microsoft
/
WSL2-Linux-Kernel
зеркало из https://github.com/microsoft/WSL2-Linux-Kernel.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
WSL2-Linux-Kernel/fs/io_uring.c

10195 строки
245 KiB
C
Исходник Ответственный История

// SPDX-License-Identifier: GPL-2.0
/*
* Shared application/kernel submission and completion ring pairs, for
* supporting fast/efficient IO.
*
* A note on the read/write ordering memory barriers that are matched between
* the application and kernel side.
*
* After the application reads the CQ ring tail, it must use an
* appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
* before writing the tail (using smp_load_acquire to read the tail will
* do). It also needs a smp_mb() before updating CQ head (ordering the
* entry load(s) with the head store), pairing with an implicit barrier
* through a control-dependency in io_get_cqring (smp_store_release to
* store head will do). Failure to do so could lead to reading invalid
* CQ entries.
*
* Likewise, the application must use an appropriate smp_wmb() before
* writing the SQ tail (ordering SQ entry stores with the tail store),
* which pairs with smp_load_acquire in io_get_sqring (smp_store_release
* to store the tail will do). And it needs a barrier ordering the SQ
* head load before writing new SQ entries (smp_load_acquire to read
* head will do).
*
* When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
* needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
* updating the SQ tail; a full memory barrier smp_mb() is needed
* between.
*
* Also see the examples in the liburing library:
*
* git://git.kernel.dk/liburing
*
* io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
* from data shared between the kernel and application. This is done both
* for ordering purposes, but also to ensure that once a value is loaded from
* data that the application could potentially modify, it remains stable.
*
* Copyright (C) 2018-2019 Jens Axboe
* Copyright (c) 2018-2019 Christoph Hellwig
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <net/compat.h>
#include <linux/refcount.h>
#include <linux/uio.h>
#include <linux/bits.h>
#include <linux/sched/signal.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/blkdev.h>
#include <linux/bvec.h>
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
#include <linux/nospec.h>
#include <linux/sizes.h>
#include <linux/hugetlb.h>
#include <linux/highmem.h>
#include <linux/namei.h>
#include <linux/fsnotify.h>
#include <linux/fadvise.h>
#include <linux/eventpoll.h>
#include <linux/fs_struct.h>
#include <linux/splice.h>
#include <linux/task_work.h>
#include <linux/pagemap.h>
#include <linux/io_uring.h>
#include <linux/blk-cgroup.h>
#include <linux/audit.h>
#define CREATE_TRACE_POINTS
#include <trace/events/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "internal.h"
#include "io-wq.h"
#define IORING_MAX_ENTRIES 32768
#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
/*
* Shift of 9 is 512 entries, or exactly one page on 64-bit archs
*/
#define IORING_FILE_TABLE_SHIFT 9
#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
IORING_REGISTER_LAST + IORING_OP_LAST)
struct io_uring {
u32 head ____cacheline_aligned_in_smp;
u32 tail ____cacheline_aligned_in_smp;
};
/*
* This data is shared with the application through the mmap at offsets
* IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
*
* The offsets to the member fields are published through struct
* io_sqring_offsets when calling io_uring_setup.
*/
struct io_rings {
/*
* Head and tail offsets into the ring; the offsets need to be
* masked to get valid indices.
*
* The kernel controls head of the sq ring and the tail of the cq ring,
* and the application controls tail of the sq ring and the head of the
* cq ring.
*/
struct io_uring sq, cq;
/*
* Bitmasks to apply to head and tail offsets (constant, equals
* ring_entries - 1)
*/
u32 sq_ring_mask, cq_ring_mask;
/* Ring sizes (constant, power of 2) */
u32 sq_ring_entries, cq_ring_entries;
/*
* Number of invalid entries dropped by the kernel due to
* invalid index stored in array
*
* Written by the kernel, shouldn't be modified by the
* application (i.e. get number of "new events" by comparing to
* cached value).
*
* After a new SQ head value was read by the application this
* counter includes all submissions that were dropped reaching
* the new SQ head (and possibly more).
*/
u32 sq_dropped;
/*
* Runtime SQ flags
*
* Written by the kernel, shouldn't be modified by the
* application.
*
* The application needs a full memory barrier before checking
* for IORING_SQ_NEED_WAKEUP after updating the sq tail.
*/
u32 sq_flags;
/*
* Runtime CQ flags
*
* Written by the application, shouldn't be modified by the
* kernel.
*/
u32 cq_flags;
/*
* Number of completion events lost because the queue was full;
* this should be avoided by the application by making sure
* there are not more requests pending than there is space in
* the completion queue.
*
* Written by the kernel, shouldn't be modified by the
* application (i.e. get number of "new events" by comparing to
* cached value).
*
* As completion events come in out of order this counter is not
* ordered with any other data.
*/
u32 cq_overflow;
/*
* Ring buffer of completion events.
*
* The kernel writes completion events fresh every time they are
* produced, so the application is allowed to modify pending
* entries.
*/
struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
};
struct io_mapped_ubuf {
u64 ubuf;
size_t len;
struct bio_vec *bvec;
unsigned int nr_bvecs;
unsigned long acct_pages;
};
struct fixed_file_table {
struct file **files;
};
struct fixed_file_ref_node {
struct percpu_ref refs;
struct list_head node;
struct list_head file_list;
struct fixed_file_data *file_data;
struct llist_node llist;
bool done;
};
struct fixed_file_data {
struct fixed_file_table *table;
struct io_ring_ctx *ctx;
struct fixed_file_ref_node *node;
struct percpu_ref refs;
struct completion done;
struct list_head ref_list;
spinlock_t lock;
};
struct io_buffer {
struct list_head list;
__u64 addr;
__s32 len;
__u16 bid;
};
struct io_restriction {
DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
u8 sqe_flags_allowed;
u8 sqe_flags_required;
bool registered;
};
struct io_sq_data {
refcount_t refs;
struct mutex lock;
/* ctx's that are using this sqd */
struct list_head ctx_list;
struct list_head ctx_new_list;
struct mutex ctx_lock;
struct task_struct *thread;
struct wait_queue_head wait;
unsigned sq_thread_idle;
};
struct io_ring_ctx {
struct {
struct percpu_ref refs;
} ____cacheline_aligned_in_smp;
struct {
unsigned int flags;
unsigned int compat: 1;
unsigned int limit_mem: 1;
unsigned int cq_overflow_flushed: 1;
unsigned int drain_next: 1;
unsigned int eventfd_async: 1;
unsigned int restricted: 1;
unsigned int sqo_dead: 1;
/*
* Ring buffer of indices into array of io_uring_sqe, which is
* mmapped by the application using the IORING_OFF_SQES offset.
*
* This indirection could e.g. be used to assign fixed
* io_uring_sqe entries to operations and only submit them to
* the queue when needed.
*
* The kernel modifies neither the indices array nor the entries
* array.
*/
u32 *sq_array;
unsigned cached_sq_head;
unsigned sq_entries;
unsigned sq_mask;
unsigned sq_thread_idle;
unsigned cached_sq_dropped;
unsigned cached_cq_overflow;
unsigned long sq_check_overflow;
struct list_head defer_list;
struct list_head timeout_list;
struct list_head cq_overflow_list;
struct io_uring_sqe *sq_sqes;
} ____cacheline_aligned_in_smp;
struct io_rings *rings;
/* IO offload */
struct io_wq *io_wq;
/*
* For SQPOLL usage - we hold a reference to the parent task, so we
* have access to the ->files
*/
struct task_struct *sqo_task;
/* Only used for accounting purposes */
struct mm_struct *mm_account;
#ifdef CONFIG_BLK_CGROUP
struct cgroup_subsys_state *sqo_blkcg_css;
#endif
struct io_sq_data *sq_data; /* if using sq thread polling */
struct wait_queue_head sqo_sq_wait;
struct list_head sqd_list;
/*
* If used, fixed file set. Writers must ensure that ->refs is dead,
* readers must ensure that ->refs is alive as long as the file* is
* used. Only updated through io_uring_register(2).
*/
struct fixed_file_data *file_data;
unsigned nr_user_files;
/* if used, fixed mapped user buffers */
unsigned nr_user_bufs;
struct io_mapped_ubuf *user_bufs;
struct user_struct *user;
const struct cred *creds;
#ifdef CONFIG_AUDIT
kuid_t loginuid;
unsigned int sessionid;
#endif
struct completion ref_comp;
struct completion sq_thread_comp;
/* if all else fails... */
struct io_kiocb *fallback_req;
#if defined(CONFIG_UNIX)
struct socket *ring_sock;
#endif
struct idr io_buffer_idr;
struct idr personality_idr;
struct {
unsigned cached_cq_tail;
unsigned cq_entries;
unsigned cq_mask;
atomic_t cq_timeouts;
unsigned cq_last_tm_flush;
unsigned long cq_check_overflow;
struct wait_queue_head cq_wait;
struct fasync_struct *cq_fasync;
struct eventfd_ctx *cq_ev_fd;
} ____cacheline_aligned_in_smp;
struct {
struct mutex uring_lock;
wait_queue_head_t wait;
} ____cacheline_aligned_in_smp;
struct {
spinlock_t completion_lock;
/*
* ->iopoll_list is protected by the ctx->uring_lock for
* io_uring instances that don't use IORING_SETUP_SQPOLL.
* For SQPOLL, only the single threaded io_sq_thread() will
* manipulate the list, hence no extra locking is needed there.
*/
struct list_head iopoll_list;
struct hlist_head *cancel_hash;
unsigned cancel_hash_bits;
bool poll_multi_file;
spinlock_t inflight_lock;
struct list_head inflight_list;
} ____cacheline_aligned_in_smp;
struct delayed_work file_put_work;
struct llist_head file_put_llist;
struct work_struct exit_work;
struct io_restriction restrictions;
};
/*
* First field must be the file pointer in all the
* iocb unions! See also 'struct kiocb' in <linux/fs.h>
*/
struct io_poll_iocb {
struct file *file;
struct wait_queue_head *head;
__poll_t events;
bool done;
bool canceled;
struct wait_queue_entry wait;
};
struct io_poll_remove {
struct file *file;
u64 addr;
};
struct io_close {
struct file *file;
struct file *put_file;
int fd;
};
struct io_timeout_data {
struct io_kiocb *req;
struct hrtimer timer;
struct timespec64 ts;
enum hrtimer_mode mode;
};
struct io_accept {
struct file *file;
struct sockaddr __user *addr;
int __user *addr_len;
int flags;
unsigned long nofile;
};
struct io_sync {
struct file *file;
loff_t len;
loff_t off;
int flags;
int mode;
};
struct io_cancel {
struct file *file;
u64 addr;
};
struct io_timeout {
struct file *file;
u32 off;
u32 target_seq;
struct list_head list;
/* head of the link, used by linked timeouts only */
struct io_kiocb *head;
};
struct io_timeout_rem {
struct file *file;
u64 addr;
/* timeout update */
struct timespec64 ts;
u32 flags;
};
struct io_rw {
/* NOTE: kiocb has the file as the first member, so don't do it here */
struct kiocb kiocb;
u64 addr;
u64 len;
};
struct io_connect {
struct file *file;
struct sockaddr __user *addr;
int addr_len;
};
struct io_sr_msg {
struct file *file;
union {
struct user_msghdr __user *umsg;
void __user *buf;
};
int msg_flags;
int bgid;
size_t len;
struct io_buffer *kbuf;
};
struct io_open {
struct file *file;
int dfd;
bool ignore_nonblock;
struct filename *filename;
struct open_how how;
unsigned long nofile;
};
struct io_files_update {
struct file *file;
u64 arg;
u32 nr_args;
u32 offset;
};
struct io_fadvise {
struct file *file;
u64 offset;
u32 len;
u32 advice;
};
struct io_madvise {
struct file *file;
u64 addr;
u32 len;
u32 advice;
};
struct io_epoll {
struct file *file;
int epfd;
int op;
int fd;
struct epoll_event event;
};
struct io_splice {
struct file *file_out;
struct file *file_in;
loff_t off_out;
loff_t off_in;
u64 len;
unsigned int flags;
};
struct io_provide_buf {
struct file *file;
__u64 addr;
__s32 len;
__u32 bgid;
__u16 nbufs;
__u16 bid;
};
struct io_statx {
struct file *file;
int dfd;
unsigned int mask;
unsigned int flags;
const char __user *filename;
struct statx __user *buffer;
};
struct io_shutdown {
struct file *file;
int how;
};
struct io_rename {
struct file *file;
int old_dfd;
int new_dfd;
struct filename *oldpath;
struct filename *newpath;
int flags;
};
struct io_unlink {
struct file *file;
int dfd;
int flags;
struct filename *filename;
};
struct io_completion {
struct file *file;
struct list_head list;
int cflags;
};
struct io_async_connect {
struct sockaddr_storage address;
};
struct io_async_msghdr {
struct iovec fast_iov[UIO_FASTIOV];
struct iovec *iov;
struct sockaddr __user *uaddr;
struct msghdr msg;
struct sockaddr_storage addr;
};
struct io_async_rw {
struct iovec fast_iov[UIO_FASTIOV];
const struct iovec *free_iovec;
struct iov_iter iter;
size_t bytes_done;
struct wait_page_queue wpq;
};
enum {
REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
REQ_F_FAIL_LINK_BIT,
REQ_F_INFLIGHT_BIT,
REQ_F_CUR_POS_BIT,
REQ_F_NOWAIT_BIT,
REQ_F_LINK_TIMEOUT_BIT,
REQ_F_ISREG_BIT,
REQ_F_NEED_CLEANUP_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
REQ_F_NO_FILE_TABLE_BIT,
REQ_F_WORK_INITIALIZED_BIT,
REQ_F_LTIMEOUT_ACTIVE_BIT,
/* not a real bit, just to check we're not overflowing the space */
__REQ_F_LAST_BIT,
};
enum {
/* ctx owns file */
REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
/* drain existing IO first */
REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
/* linked sqes */
REQ_F_LINK = BIT(REQ_F_LINK_BIT),
/* doesn't sever on completion < 0 */
REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
/* IOSQE_ASYNC */
REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
/* IOSQE_BUFFER_SELECT */
REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
/* fail rest of links */
REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
/* on inflight list */
REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
/* read/write uses file position */
REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
/* must not punt to workers */
REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
/* has or had linked timeout */
REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
/* regular file */
REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
/* needs cleanup */
REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
/* already went through poll handler */
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
/* buffer already selected */
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
/* doesn't need file table for this request */
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
/* io_wq_work is initialized */
REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
/* linked timeout is active, i.e. prepared by link's head */
REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT),
};
struct async_poll {
struct io_poll_iocb poll;
struct io_poll_iocb *double_poll;
};
/*
* NOTE! Each of the iocb union members has the file pointer
* as the first entry in their struct definition. So you can
* access the file pointer through any of the sub-structs,
* or directly as just 'ki_filp' in this struct.
*/
struct io_kiocb {
union {
struct file *file;
struct io_rw rw;
struct io_poll_iocb poll;
struct io_poll_remove poll_remove;
struct io_accept accept;
struct io_sync sync;
struct io_cancel cancel;
struct io_timeout timeout;
struct io_timeout_rem timeout_rem;
struct io_connect connect;
struct io_sr_msg sr_msg;
struct io_open open;
struct io_close close;
struct io_files_update files_update;
struct io_fadvise fadvise;
struct io_madvise madvise;
struct io_epoll epoll;
struct io_splice splice;
struct io_provide_buf pbuf;
struct io_statx statx;
struct io_shutdown shutdown;
struct io_rename rename;
struct io_unlink unlink;
/* use only after cleaning per-op data, see io_clean_op() */
struct io_completion compl;
};
/* opcode allocated if it needs to store data for async defer */
void *async_data;
u8 opcode;
/* polled IO has completed */
u8 iopoll_completed;
u16 buf_index;
u32 result;
struct io_ring_ctx *ctx;
unsigned int flags;
refcount_t refs;
struct task_struct *task;
u64 user_data;
struct io_kiocb *link;
struct percpu_ref *fixed_file_refs;
/*
* 1. used with ctx->iopoll_list with reads/writes
* 2. to track reqs with ->files (see io_op_def::file_table)
*/
struct list_head inflight_entry;
struct callback_head task_work;
/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
struct hlist_node hash_node;
struct async_poll *apoll;
struct io_wq_work work;
};
struct io_defer_entry {
struct list_head list;
struct io_kiocb *req;
u32 seq;
};
#define IO_IOPOLL_BATCH 8
struct io_comp_state {
unsigned int nr;
struct list_head list;
struct io_ring_ctx *ctx;
};
struct io_submit_state {
struct blk_plug plug;
/*
* io_kiocb alloc cache
*/
void *reqs[IO_IOPOLL_BATCH];
unsigned int free_reqs;
bool plug_started;
/*
* Batch completion logic
*/
struct io_comp_state comp;
/*
* File reference cache
*/
struct file *file;
unsigned int fd;
unsigned int file_refs;
unsigned int ios_left;
};
struct io_op_def {
/* needs req->file assigned */
unsigned needs_file : 1;
/* don't fail if file grab fails */
unsigned needs_file_no_error : 1;
/* hash wq insertion if file is a regular file */
unsigned hash_reg_file : 1;
/* unbound wq insertion if file is a non-regular file */
unsigned unbound_nonreg_file : 1;
/* opcode is not supported by this kernel */
unsigned not_supported : 1;
/* set if opcode supports polled "wait" */
unsigned pollin : 1;
unsigned pollout : 1;
/* op supports buffer selection */
unsigned buffer_select : 1;
/* must always have async data allocated */
unsigned needs_async_data : 1;
/* should block plug */
unsigned plug : 1;
/* size of async data needed, if any */
unsigned short async_size;
unsigned work_flags;
};
static const struct io_op_def io_op_defs[] = {
[IORING_OP_NOP] = {},
[IORING_OP_READV] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.buffer_select = 1,
.needs_async_data = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_WRITEV] = {
.needs_file = 1,
.hash_reg_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.needs_async_data = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
IO_WQ_WORK_FSIZE,
},
[IORING_OP_FSYNC] = {
.needs_file = 1,
.work_flags = IO_WQ_WORK_BLKCG,
},
[IORING_OP_READ_FIXED] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM,
},
[IORING_OP_WRITE_FIXED] = {
.needs_file = 1,
.hash_reg_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE |
IO_WQ_WORK_MM,
},
[IORING_OP_POLL_ADD] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
},
[IORING_OP_POLL_REMOVE] = {},
[IORING_OP_SYNC_FILE_RANGE] = {
.needs_file = 1,
.work_flags = IO_WQ_WORK_BLKCG,
},
[IORING_OP_SENDMSG] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.needs_async_data = 1,
.async_size = sizeof(struct io_async_msghdr),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_RECVMSG] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.buffer_select = 1,
.needs_async_data = 1,
.async_size = sizeof(struct io_async_msghdr),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_TIMEOUT] = {
.needs_async_data = 1,
.async_size = sizeof(struct io_timeout_data),
.work_flags = IO_WQ_WORK_MM,
},
[IORING_OP_TIMEOUT_REMOVE] = {
/* used by timeout updates' prep() */
.work_flags = IO_WQ_WORK_MM,
},
[IORING_OP_ACCEPT] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
},
[IORING_OP_ASYNC_CANCEL] = {},
[IORING_OP_LINK_TIMEOUT] = {
.needs_async_data = 1,
.async_size = sizeof(struct io_timeout_data),
.work_flags = IO_WQ_WORK_MM,
},
[IORING_OP_CONNECT] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.needs_async_data = 1,
.async_size = sizeof(struct io_async_connect),
.work_flags = IO_WQ_WORK_MM,
},
[IORING_OP_FALLOCATE] = {
.needs_file = 1,
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE,
},
[IORING_OP_OPENAT] = {
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG |
IO_WQ_WORK_FS | IO_WQ_WORK_MM,
},
[IORING_OP_CLOSE] = {
.needs_file = 1,
.needs_file_no_error = 1,
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG,
},
[IORING_OP_FILES_UPDATE] = {
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM,
},
[IORING_OP_STATX] = {
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM |
IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
},
[IORING_OP_READ] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.buffer_select = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_WRITE] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.plug = 1,
.async_size = sizeof(struct io_async_rw),
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
IO_WQ_WORK_FSIZE,
},
[IORING_OP_FADVISE] = {
.needs_file = 1,
.work_flags = IO_WQ_WORK_BLKCG,
},
[IORING_OP_MADVISE] = {
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_SEND] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollout = 1,
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_RECV] = {
.needs_file = 1,
.unbound_nonreg_file = 1,
.pollin = 1,
.buffer_select = 1,
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
},
[IORING_OP_OPENAT2] = {
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS |
IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM,
},
[IORING_OP_EPOLL_CTL] = {
.unbound_nonreg_file = 1,
.work_flags = IO_WQ_WORK_FILES,
},
[IORING_OP_SPLICE] = {
.needs_file = 1,
.hash_reg_file = 1,
.unbound_nonreg_file = 1,
.work_flags = IO_WQ_WORK_BLKCG,
},
[IORING_OP_PROVIDE_BUFFERS] = {},
[IORING_OP_REMOVE_BUFFERS] = {},
[IORING_OP_TEE] = {
.needs_file = 1,
.hash_reg_file = 1,
.unbound_nonreg_file = 1,
},
[IORING_OP_SHUTDOWN] = {
.needs_file = 1,
},
[IORING_OP_RENAMEAT] = {
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
},
[IORING_OP_UNLINKAT] = {
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES |
IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
},
};
enum io_mem_account {
ACCT_LOCKED,
ACCT_PINNED,
};
static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
struct task_struct *task);
static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node);
static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
struct io_ring_ctx *ctx);
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
struct io_comp_state *cs);
static void io_cqring_fill_event(struct io_kiocb *req, long res);
static void io_put_req(struct io_kiocb *req);
static void io_put_req_deferred(struct io_kiocb *req, int nr);
static void io_double_put_req(struct io_kiocb *req);
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
static void __io_queue_linked_timeout(struct io_kiocb *req);
static void io_queue_linked_timeout(struct io_kiocb *req);
static int __io_sqe_files_update(struct io_ring_ctx *ctx,
struct io_uring_files_update *ip,
unsigned nr_args);
static void __io_clean_op(struct io_kiocb *req);
static struct file *io_file_get(struct io_submit_state *state,
struct io_kiocb *req, int fd, bool fixed);
static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs);
static void io_file_put_work(struct work_struct *work);
static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
struct iovec **iovec, struct iov_iter *iter,
bool needs_lock);
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
const struct iovec *fast_iov,
struct iov_iter *iter, bool force);
static void io_req_drop_files(struct io_kiocb *req);
static struct kmem_cache *req_cachep;
static const struct file_operations io_uring_fops;
struct sock *io_uring_get_socket(struct file *file)
{
#if defined(CONFIG_UNIX)
if (file->f_op == &io_uring_fops) {
struct io_ring_ctx *ctx = file->private_data;
return ctx->ring_sock->sk;
}
#endif
return NULL;
}
EXPORT_SYMBOL(io_uring_get_socket);
#define io_for_each_link(pos, head) \
for (pos = (head); pos; pos = pos->link)
static inline void io_clean_op(struct io_kiocb *req)
{
if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED))
__io_clean_op(req);
}
static inline void io_set_resource_node(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
if (!req->fixed_file_refs) {
req->fixed_file_refs = &ctx->file_data->node->refs;
percpu_ref_get(req->fixed_file_refs);
}
}
static bool io_match_task(struct io_kiocb *head,
struct task_struct *task,
struct files_struct *files)
{
struct io_kiocb *req;
if (task && head->task != task)
return false;
if (!files)
return true;
io_for_each_link(req, head) {
if (!(req->flags & REQ_F_WORK_INITIALIZED))
continue;
if (req->file && req->file->f_op == &io_uring_fops)
return true;
if ((req->work.flags & IO_WQ_WORK_FILES) &&
req->work.identity->files == files)
return true;
}
return false;
}
static void io_sq_thread_drop_mm_files(void)
{
struct files_struct *files = current->files;
struct mm_struct *mm = current->mm;
if (mm) {
kthread_unuse_mm(mm);
mmput(mm);
current->mm = NULL;
}
if (files) {
struct nsproxy *nsproxy = current->nsproxy;
task_lock(current);
current->files = NULL;
current->nsproxy = NULL;
task_unlock(current);
put_files_struct(files);
put_nsproxy(nsproxy);
}
}
static int __io_sq_thread_acquire_files(struct io_ring_ctx *ctx)
{
if (current->flags & PF_EXITING)
return -EFAULT;
if (!current->files) {
struct files_struct *files;
struct nsproxy *nsproxy;
task_lock(ctx->sqo_task);
files = ctx->sqo_task->files;
if (!files) {
task_unlock(ctx->sqo_task);
return -EOWNERDEAD;
}
atomic_inc(&files->count);
get_nsproxy(ctx->sqo_task->nsproxy);
nsproxy = ctx->sqo_task->nsproxy;
task_unlock(ctx->sqo_task);
task_lock(current);
current->files = files;
current->nsproxy = nsproxy;
task_unlock(current);
}
return 0;
}
static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
{
struct mm_struct *mm;
if (current->flags & PF_EXITING)
return -EFAULT;
if (current->mm)
return 0;
/* Should never happen */
if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL)))
return -EFAULT;
task_lock(ctx->sqo_task);
mm = ctx->sqo_task->mm;
if (unlikely(!mm || !mmget_not_zero(mm)))
mm = NULL;
task_unlock(ctx->sqo_task);
if (mm) {
kthread_use_mm(mm);
return 0;
}
return -EFAULT;
}
static int io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx,
struct io_kiocb *req)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
int ret;
if (def->work_flags & IO_WQ_WORK_MM) {
ret = __io_sq_thread_acquire_mm(ctx);
if (unlikely(ret))
return ret;
}
if (def->needs_file || (def->work_flags & IO_WQ_WORK_FILES)) {
ret = __io_sq_thread_acquire_files(ctx);
if (unlikely(ret))
return ret;
}
return 0;
}
static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx,
struct cgroup_subsys_state **cur_css)
{
#ifdef CONFIG_BLK_CGROUP
/* puts the old one when swapping */
if (*cur_css != ctx->sqo_blkcg_css) {
kthread_associate_blkcg(ctx->sqo_blkcg_css);
*cur_css = ctx->sqo_blkcg_css;
}
#endif
}
static void io_sq_thread_unassociate_blkcg(void)
{
#ifdef CONFIG_BLK_CGROUP
kthread_associate_blkcg(NULL);
#endif
}
static inline void req_set_fail_links(struct io_kiocb *req)
{
if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
req->flags |= REQ_F_FAIL_LINK;
}
/*
* None of these are dereferenced, they are simply used to check if any of
* them have changed. If we're under current and check they are still the
* same, we're fine to grab references to them for actual out-of-line use.
*/
static void io_init_identity(struct io_identity *id)
{
id->files = current->files;
id->mm = current->mm;
#ifdef CONFIG_BLK_CGROUP
rcu_read_lock();
id->blkcg_css = blkcg_css();
rcu_read_unlock();
#endif
id->creds = current_cred();
id->nsproxy = current->nsproxy;
id->fs = current->fs;
id->fsize = rlimit(RLIMIT_FSIZE);
#ifdef CONFIG_AUDIT
id->loginuid = current->loginuid;
id->sessionid = current->sessionid;
#endif
refcount_set(&id->count, 1);
}
static inline void __io_req_init_async(struct io_kiocb *req)
{
memset(&req->work, 0, sizeof(req->work));
req->flags |= REQ_F_WORK_INITIALIZED;
}
/*
* Note: must call io_req_init_async() for the first time you
* touch any members of io_wq_work.
*/
static inline void io_req_init_async(struct io_kiocb *req)
{
struct io_uring_task *tctx = current->io_uring;
if (req->flags & REQ_F_WORK_INITIALIZED)
return;
__io_req_init_async(req);
/* Grab a ref if this isn't our static identity */
req->work.identity = tctx->identity;
if (tctx->identity != &tctx->__identity)
refcount_inc(&req->work.identity->count);
}
static inline bool io_async_submit(struct io_ring_ctx *ctx)
{
return ctx->flags & IORING_SETUP_SQPOLL;
}
static void io_ring_ctx_ref_free(struct percpu_ref *ref)
{
struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
complete(&ctx->ref_comp);
}
static inline bool io_is_timeout_noseq(struct io_kiocb *req)
{
return !req->timeout.off;
}
static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
{
struct io_ring_ctx *ctx;
int hash_bits;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return NULL;
ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
if (!ctx->fallback_req)
goto err;
/*
* Use 5 bits less than the max cq entries, that should give us around
* 32 entries per hash list if totally full and uniformly spread.
*/
hash_bits = ilog2(p->cq_entries);
hash_bits -= 5;
if (hash_bits <= 0)
hash_bits = 1;
ctx->cancel_hash_bits = hash_bits;
ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
GFP_KERNEL);
if (!ctx->cancel_hash)
goto err;
__hash_init(ctx->cancel_hash, 1U << hash_bits);
if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
goto err;
ctx->flags = p->flags;
init_waitqueue_head(&ctx->sqo_sq_wait);
INIT_LIST_HEAD(&ctx->sqd_list);
init_waitqueue_head(&ctx->cq_wait);
INIT_LIST_HEAD(&ctx->cq_overflow_list);
init_completion(&ctx->ref_comp);
init_completion(&ctx->sq_thread_comp);
idr_init(&ctx->io_buffer_idr);
idr_init(&ctx->personality_idr);
mutex_init(&ctx->uring_lock);
init_waitqueue_head(&ctx->wait);
spin_lock_init(&ctx->completion_lock);
INIT_LIST_HEAD(&ctx->iopoll_list);
INIT_LIST_HEAD(&ctx->defer_list);
INIT_LIST_HEAD(&ctx->timeout_list);
spin_lock_init(&ctx->inflight_lock);
INIT_LIST_HEAD(&ctx->inflight_list);
INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
init_llist_head(&ctx->file_put_llist);
return ctx;
err:
if (ctx->fallback_req)
kmem_cache_free(req_cachep, ctx->fallback_req);
kfree(ctx->cancel_hash);
kfree(ctx);
return NULL;
}
static bool req_need_defer(struct io_kiocb *req, u32 seq)
{
if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
struct io_ring_ctx *ctx = req->ctx;
return seq != ctx->cached_cq_tail
+ READ_ONCE(ctx->cached_cq_overflow);
}
return false;
}
static void __io_commit_cqring(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
/* order cqe stores with ring update */
smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
}
static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req)
{
if (req->work.identity == &tctx->__identity)
return;
if (refcount_dec_and_test(&req->work.identity->count))
kfree(req->work.identity);
}
static void io_req_clean_work(struct io_kiocb *req)
{
if (!(req->flags & REQ_F_WORK_INITIALIZED))
return;
req->flags &= ~REQ_F_WORK_INITIALIZED;
if (req->work.flags & IO_WQ_WORK_MM) {
mmdrop(req->work.identity->mm);
req->work.flags &= ~IO_WQ_WORK_MM;
}
#ifdef CONFIG_BLK_CGROUP
if (req->work.flags & IO_WQ_WORK_BLKCG) {
css_put(req->work.identity->blkcg_css);
req->work.flags &= ~IO_WQ_WORK_BLKCG;
}
#endif
if (req->work.flags & IO_WQ_WORK_CREDS) {
put_cred(req->work.identity->creds);
req->work.flags &= ~IO_WQ_WORK_CREDS;
}
if (req->work.flags & IO_WQ_WORK_FS) {
struct fs_struct *fs = req->work.identity->fs;
spin_lock(&req->work.identity->fs->lock);
if (--fs->users)
fs = NULL;
spin_unlock(&req->work.identity->fs->lock);
if (fs)
free_fs_struct(fs);
req->work.flags &= ~IO_WQ_WORK_FS;
}
if (req->flags & REQ_F_INFLIGHT)
io_req_drop_files(req);
io_put_identity(req->task->io_uring, req);
}
/*
* Create a private copy of io_identity, since some fields don't match
* the current context.
*/
static bool io_identity_cow(struct io_kiocb *req)
{
struct io_uring_task *tctx = current->io_uring;
const struct cred *creds = NULL;
struct io_identity *id;
if (req->work.flags & IO_WQ_WORK_CREDS)
creds = req->work.identity->creds;
id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL);
if (unlikely(!id)) {
req->work.flags |= IO_WQ_WORK_CANCEL;
return false;
}
/*
* We can safely just re-init the creds we copied Either the field
* matches the current one, or we haven't grabbed it yet. The only
* exception is ->creds, through registered personalities, so handle
* that one separately.
*/
io_init_identity(id);
if (creds)
id->creds = creds;
/* add one for this request */
refcount_inc(&id->count);
/* drop tctx and req identity references, if needed */
if (tctx->identity != &tctx->__identity &&
refcount_dec_and_test(&tctx->identity->count))
kfree(tctx->identity);
if (req->work.identity != &tctx->__identity &&
refcount_dec_and_test(&req->work.identity->count))
kfree(req->work.identity);
req->work.identity = id;
tctx->identity = id;
return true;
}
static bool io_grab_identity(struct io_kiocb *req)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
struct io_identity *id = req->work.identity;
struct io_ring_ctx *ctx = req->ctx;
if (def->work_flags & IO_WQ_WORK_FSIZE) {
if (id->fsize != rlimit(RLIMIT_FSIZE))
return false;
req->work.flags |= IO_WQ_WORK_FSIZE;
}
#ifdef CONFIG_BLK_CGROUP
if (!(req->work.flags & IO_WQ_WORK_BLKCG) &&
(def->work_flags & IO_WQ_WORK_BLKCG)) {
rcu_read_lock();
if (id->blkcg_css != blkcg_css()) {
rcu_read_unlock();
return false;
}
/*
* This should be rare, either the cgroup is dying or the task
* is moving cgroups. Just punt to root for the handful of ios.
*/
if (css_tryget_online(id->blkcg_css))
req->work.flags |= IO_WQ_WORK_BLKCG;
rcu_read_unlock();
}
#endif
if (!(req->work.flags & IO_WQ_WORK_CREDS)) {
if (id->creds != current_cred())
return false;
get_cred(id->creds);
req->work.flags |= IO_WQ_WORK_CREDS;
}
#ifdef CONFIG_AUDIT
if (!uid_eq(current->loginuid, id->loginuid) ||
current->sessionid != id->sessionid)
return false;
#endif
if (!(req->work.flags & IO_WQ_WORK_FS) &&
(def->work_flags & IO_WQ_WORK_FS)) {
if (current->fs != id->fs)
return false;
spin_lock(&id->fs->lock);
if (!id->fs->in_exec) {
id->fs->users++;
req->work.flags |= IO_WQ_WORK_FS;
} else {
req->work.flags |= IO_WQ_WORK_CANCEL;
}
spin_unlock(&current->fs->lock);
}
if (!(req->work.flags & IO_WQ_WORK_FILES) &&
(def->work_flags & IO_WQ_WORK_FILES) &&
!(req->flags & REQ_F_NO_FILE_TABLE)) {
if (id->files != current->files ||
id->nsproxy != current->nsproxy)
return false;
atomic_inc(&id->files->count);
get_nsproxy(id->nsproxy);
if (!(req->flags & REQ_F_INFLIGHT)) {
req->flags |= REQ_F_INFLIGHT;
spin_lock_irq(&ctx->inflight_lock);
list_add(&req->inflight_entry, &ctx->inflight_list);
spin_unlock_irq(&ctx->inflight_lock);
}
req->work.flags |= IO_WQ_WORK_FILES;
}
if (!(req->work.flags & IO_WQ_WORK_MM) &&
(def->work_flags & IO_WQ_WORK_MM)) {
if (id->mm != current->mm)
return false;
mmgrab(id->mm);
req->work.flags |= IO_WQ_WORK_MM;
}
return true;
}
static void io_prep_async_work(struct io_kiocb *req)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
struct io_ring_ctx *ctx = req->ctx;
io_req_init_async(req);
if (req->flags & REQ_F_FORCE_ASYNC)
req->work.flags |= IO_WQ_WORK_CONCURRENT;
if (req->flags & REQ_F_ISREG) {
if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
io_wq_hash_work(&req->work, file_inode(req->file));
} else {
if (def->unbound_nonreg_file)
req->work.flags |= IO_WQ_WORK_UNBOUND;
}
/* if we fail grabbing identity, we must COW, regrab, and retry */
if (io_grab_identity(req))
return;
if (!io_identity_cow(req))
return;
/* can't fail at this point */
if (!io_grab_identity(req))
WARN_ON(1);
}
static void io_prep_async_link(struct io_kiocb *req)
{
struct io_kiocb *cur;
io_for_each_link(cur, req)
io_prep_async_work(cur);
}
static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *link = io_prep_linked_timeout(req);
trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
&req->work, req->flags);
io_wq_enqueue(ctx->io_wq, &req->work);
return link;
}
static void io_queue_async_work(struct io_kiocb *req)
{
struct io_kiocb *link;
/* init ->work of the whole link before punting */
io_prep_async_link(req);
link = __io_queue_async_work(req);
if (link)
io_queue_linked_timeout(link);
}
static void io_kill_timeout(struct io_kiocb *req)
{
struct io_timeout_data *io = req->async_data;
int ret;
ret = hrtimer_try_to_cancel(&io->timer);
if (ret != -1) {
atomic_set(&req->ctx->cq_timeouts,
atomic_read(&req->ctx->cq_timeouts) + 1);
list_del_init(&req->timeout.list);
io_cqring_fill_event(req, 0);
io_put_req_deferred(req, 1);
}
}
/*
* Returns true if we found and killed one or more timeouts
*/
static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
struct files_struct *files)
{
struct io_kiocb *req, *tmp;
int canceled = 0;
spin_lock_irq(&ctx->completion_lock);
list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
if (io_match_task(req, tsk, files)) {
io_kill_timeout(req);
canceled++;
}
}
spin_unlock_irq(&ctx->completion_lock);
return canceled != 0;
}
static void __io_queue_deferred(struct io_ring_ctx *ctx)
{
do {
struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
struct io_defer_entry, list);
struct io_kiocb *link;
if (req_need_defer(de->req, de->seq))
break;
list_del_init(&de->list);
/* punt-init is done before queueing for defer */
link = __io_queue_async_work(de->req);
if (link) {
__io_queue_linked_timeout(link);
/* drop submission reference */
io_put_req_deferred(link, 1);
}
kfree(de);
} while (!list_empty(&ctx->defer_list));
}
static void io_flush_timeouts(struct io_ring_ctx *ctx)
{
u32 seq;
if (list_empty(&ctx->timeout_list))
return;
seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
do {
u32 events_needed, events_got;
struct io_kiocb *req = list_first_entry(&ctx->timeout_list,
struct io_kiocb, timeout.list);
if (io_is_timeout_noseq(req))
break;
/*
* Since seq can easily wrap around over time, subtract
* the last seq at which timeouts were flushed before comparing.
* Assuming not more than 2^31-1 events have happened since,
* these subtractions won't have wrapped, so we can check if
* target is in [last_seq, current_seq] by comparing the two.
*/
events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
events_got = seq - ctx->cq_last_tm_flush;
if (events_got < events_needed)
break;
list_del_init(&req->timeout.list);
io_kill_timeout(req);
} while (!list_empty(&ctx->timeout_list));
ctx->cq_last_tm_flush = seq;
}
static void io_commit_cqring(struct io_ring_ctx *ctx)
{
io_flush_timeouts(ctx);
__io_commit_cqring(ctx);
if (unlikely(!list_empty(&ctx->defer_list)))
__io_queue_deferred(ctx);
}
static inline bool io_sqring_full(struct io_ring_ctx *ctx)
{
struct io_rings *r = ctx->rings;
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
}
static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
unsigned tail;
tail = ctx->cached_cq_tail;
/*
* writes to the cq entry need to come after reading head; the
* control dependency is enough as we're using WRITE_ONCE to
* fill the cq entry
*/
if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
return NULL;
ctx->cached_cq_tail++;
return &rings->cqes[tail & ctx->cq_mask];
}
static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
{
if (!ctx->cq_ev_fd)
return false;
if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
return false;
if (!ctx->eventfd_async)
return true;
return io_wq_current_is_worker();
}
static inline unsigned __io_cqring_events(struct io_ring_ctx *ctx)
{
return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
}
static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
{
/* see waitqueue_active() comment */
smp_mb();
if (waitqueue_active(&ctx->wait))
wake_up(&ctx->wait);
if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
wake_up(&ctx->sq_data->wait);
if (io_should_trigger_evfd(ctx))
eventfd_signal(ctx->cq_ev_fd, 1);
if (waitqueue_active(&ctx->cq_wait)) {
wake_up_interruptible(&ctx->cq_wait);
kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
}
}
static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
{
/* see waitqueue_active() comment */
smp_mb();
if (ctx->flags & IORING_SETUP_SQPOLL) {
if (waitqueue_active(&ctx->wait))
wake_up(&ctx->wait);
}
if (io_should_trigger_evfd(ctx))
eventfd_signal(ctx->cq_ev_fd, 1);
if (waitqueue_active(&ctx->cq_wait)) {
wake_up_interruptible(&ctx->cq_wait);
kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
}
}
/* Returns true if there are no backlogged entries after the flush */
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
struct task_struct *tsk,
struct files_struct *files)
{
struct io_rings *rings = ctx->rings;
struct io_kiocb *req, *tmp;
struct io_uring_cqe *cqe;
unsigned long flags;
bool all_flushed;
LIST_HEAD(list);
if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries)
return false;
spin_lock_irqsave(&ctx->completion_lock, flags);
list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
if (!io_match_task(req, tsk, files))
continue;
cqe = io_get_cqring(ctx);
if (!cqe && !force)
break;
list_move(&req->compl.list, &list);
if (cqe) {
WRITE_ONCE(cqe->user_data, req->user_data);
WRITE_ONCE(cqe->res, req->result);
WRITE_ONCE(cqe->flags, req->compl.cflags);
} else {
ctx->cached_cq_overflow++;
WRITE_ONCE(ctx->rings->cq_overflow,
ctx->cached_cq_overflow);
}
}
all_flushed = list_empty(&ctx->cq_overflow_list);
if (all_flushed) {
clear_bit(0, &ctx->sq_check_overflow);
clear_bit(0, &ctx->cq_check_overflow);
ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
}
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
io_cqring_ev_posted(ctx);
while (!list_empty(&list)) {
req = list_first_entry(&list, struct io_kiocb, compl.list);
list_del(&req->compl.list);
io_put_req(req);
}
return all_flushed;
}
static void io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
struct task_struct *tsk,
struct files_struct *files)
{
if (test_bit(0, &ctx->cq_check_overflow)) {
/* iopoll syncs against uring_lock, not completion_lock */
if (ctx->flags & IORING_SETUP_IOPOLL)
mutex_lock(&ctx->uring_lock);
__io_cqring_overflow_flush(ctx, force, tsk, files);
if (ctx->flags & IORING_SETUP_IOPOLL)
mutex_unlock(&ctx->uring_lock);
}
}
static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_uring_cqe *cqe;
trace_io_uring_complete(ctx, req->user_data, res);
/*
* If we can't get a cq entry, userspace overflowed the
* submission (by quite a lot). Increment the overflow count in
* the ring.
*/
cqe = io_get_cqring(ctx);
if (likely(cqe)) {
WRITE_ONCE(cqe->user_data, req->user_data);
WRITE_ONCE(cqe->res, res);
WRITE_ONCE(cqe->flags, cflags);
} else if (ctx->cq_overflow_flushed ||
atomic_read(&req->task->io_uring->in_idle)) {
/*
* If we're in ring overflow flush mode, or in task cancel mode,
* then we cannot store the request for later flushing, we need
* to drop it on the floor.
*/
ctx->cached_cq_overflow++;
WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow);
} else {
if (list_empty(&ctx->cq_overflow_list)) {
set_bit(0, &ctx->sq_check_overflow);
set_bit(0, &ctx->cq_check_overflow);
ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW;
}
io_clean_op(req);
req->result = res;
req->compl.cflags = cflags;
refcount_inc(&req->refs);
list_add_tail(&req->compl.list, &ctx->cq_overflow_list);
}
}
static void io_cqring_fill_event(struct io_kiocb *req, long res)
{
__io_cqring_fill_event(req, res, 0);
}
static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
{
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags);
__io_cqring_fill_event(req, res, cflags);
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
io_cqring_ev_posted(ctx);
}
static void io_submit_flush_completions(struct io_comp_state *cs)
{
struct io_ring_ctx *ctx = cs->ctx;
spin_lock_irq(&ctx->completion_lock);
while (!list_empty(&cs->list)) {
struct io_kiocb *req;
req = list_first_entry(&cs->list, struct io_kiocb, compl.list);
list_del(&req->compl.list);
__io_cqring_fill_event(req, req->result, req->compl.cflags);
/*
* io_free_req() doesn't care about completion_lock unless one
* of these flags is set. REQ_F_WORK_INITIALIZED is in the list
* because of a potential deadlock with req->work.fs->lock
*/
if (req->flags & (REQ_F_FAIL_LINK|REQ_F_LINK_TIMEOUT
|REQ_F_WORK_INITIALIZED)) {
spin_unlock_irq(&ctx->completion_lock);
io_put_req(req);
spin_lock_irq(&ctx->completion_lock);
} else {
io_put_req(req);
}
}
io_commit_cqring(ctx);
spin_unlock_irq(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
cs->nr = 0;
}
static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags,
struct io_comp_state *cs)
{
if (!cs) {
io_cqring_add_event(req, res, cflags);
io_put_req(req);
} else {
io_clean_op(req);
req->result = res;
req->compl.cflags = cflags;
list_add_tail(&req->compl.list, &cs->list);
if (++cs->nr >= 32)
io_submit_flush_completions(cs);
}
}
static void io_req_complete(struct io_kiocb *req, long res)
{
__io_req_complete(req, res, 0, NULL);
}
static inline bool io_is_fallback_req(struct io_kiocb *req)
{
return req == (struct io_kiocb *)
((unsigned long) req->ctx->fallback_req & ~1UL);
}
static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
{
struct io_kiocb *req;
req = ctx->fallback_req;
if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
return req;
return NULL;
}
static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
struct io_submit_state *state)
{
if (!state->free_reqs) {
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
size_t sz;
int ret;
sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
/*
* Bulk alloc is all-or-nothing. If we fail to get a batch,
* retry single alloc to be on the safe side.
*/
if (unlikely(ret <= 0)) {
state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
if (!state->reqs[0])
goto fallback;
ret = 1;
}
state->free_reqs = ret;
}
state->free_reqs--;
return state->reqs[state->free_reqs];
fallback:
return io_get_fallback_req(ctx);
}
static inline void io_put_file(struct io_kiocb *req, struct file *file,
bool fixed)
{
if (!fixed)
fput(file);
}
static void io_dismantle_req(struct io_kiocb *req)
{
io_clean_op(req);
if (req->async_data)
kfree(req->async_data);
if (req->file)
io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
if (req->fixed_file_refs)
percpu_ref_put(req->fixed_file_refs);
io_req_clean_work(req);
}
static void __io_free_req(struct io_kiocb *req)
{
struct io_uring_task *tctx = req->task->io_uring;
struct io_ring_ctx *ctx = req->ctx;
io_dismantle_req(req);
percpu_counter_dec(&tctx->inflight);
if (atomic_read(&tctx->in_idle))
wake_up(&tctx->wait);
put_task_struct(req->task);
if (likely(!io_is_fallback_req(req)))
kmem_cache_free(req_cachep, req);
else
clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req);
percpu_ref_put(&ctx->refs);
}
static inline void io_remove_next_linked(struct io_kiocb *req)
{
struct io_kiocb *nxt = req->link;
req->link = nxt->link;
nxt->link = NULL;
}
static void io_kill_linked_timeout(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *link;
bool cancelled = false;
unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags);
link = req->link;
/*
* Can happen if a linked timeout fired and link had been like
* req -> link t-out -> link t-out [-> ...]
*/
if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) {
struct io_timeout_data *io = link->async_data;
int ret;
io_remove_next_linked(req);
link->timeout.head = NULL;
ret = hrtimer_try_to_cancel(&io->timer);
if (ret != -1) {
io_cqring_fill_event(link, -ECANCELED);
io_commit_cqring(ctx);
cancelled = true;
}
}
req->flags &= ~REQ_F_LINK_TIMEOUT;
spin_unlock_irqrestore(&ctx->completion_lock, flags);
if (cancelled) {
io_cqring_ev_posted(ctx);
io_put_req(link);
}
}
static void io_fail_links(struct io_kiocb *req)
{
struct io_kiocb *link, *nxt;
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags);
link = req->link;
req->link = NULL;
while (link) {
nxt = link->link;
link->link = NULL;
trace_io_uring_fail_link(req, link);
io_cqring_fill_event(link, -ECANCELED);
/*
* It's ok to free under spinlock as they're not linked anymore,
* but avoid REQ_F_WORK_INITIALIZED because it may deadlock on
* work.fs->lock.
*/
if (link->flags & REQ_F_WORK_INITIALIZED)
io_put_req_deferred(link, 2);
else
io_double_put_req(link);
link = nxt;
}
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
io_cqring_ev_posted(ctx);
}
static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
{
if (req->flags & REQ_F_LINK_TIMEOUT)
io_kill_linked_timeout(req);
/*
* If LINK is set, we have dependent requests in this chain. If we
* didn't fail this request, queue the first one up, moving any other
* dependencies to the next request. In case of failure, fail the rest
* of the chain.
*/
if (likely(!(req->flags & REQ_F_FAIL_LINK))) {
struct io_kiocb *nxt = req->link;
req->link = NULL;
return nxt;
}
io_fail_links(req);
return NULL;
}
static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
{
if (likely(!(req->link) && !(req->flags & REQ_F_LINK_TIMEOUT)))
return NULL;
return __io_req_find_next(req);
}
static int io_req_task_work_add(struct io_kiocb *req)
{
struct task_struct *tsk = req->task;
struct io_ring_ctx *ctx = req->ctx;
enum task_work_notify_mode notify;
int ret;
if (tsk->flags & PF_EXITING)
return -ESRCH;
/*
* SQPOLL kernel thread doesn't need notification, just a wakeup. For
* all other cases, use TWA_SIGNAL unconditionally to ensure we're
* processing task_work. There's no reliable way to tell if TWA_RESUME
* will do the job.
*/
notify = TWA_NONE;
if (!(ctx->flags & IORING_SETUP_SQPOLL))
notify = TWA_SIGNAL;
ret = task_work_add(tsk, &req->task_work, notify);
if (!ret)
wake_up_process(tsk);
return ret;
}
static void __io_req_task_cancel(struct io_kiocb *req, int error)
{
struct io_ring_ctx *ctx = req->ctx;
spin_lock_irq(&ctx->completion_lock);
io_cqring_fill_event(req, error);
io_commit_cqring(ctx);
spin_unlock_irq(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
req_set_fail_links(req);
io_double_put_req(req);
}
static void io_req_task_cancel(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
struct io_ring_ctx *ctx = req->ctx;
__io_req_task_cancel(req, -ECANCELED);
percpu_ref_put(&ctx->refs);
}
static void __io_req_task_submit(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
mutex_lock(&ctx->uring_lock);
if (!ctx->sqo_dead &&
!__io_sq_thread_acquire_mm(ctx) &&
!__io_sq_thread_acquire_files(ctx))
__io_queue_sqe(req, NULL);
else
__io_req_task_cancel(req, -EFAULT);
mutex_unlock(&ctx->uring_lock);
}
static void io_req_task_submit(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
struct io_ring_ctx *ctx = req->ctx;
__io_req_task_submit(req);
percpu_ref_put(&ctx->refs);
}
static void io_req_task_queue(struct io_kiocb *req)
{
int ret;
init_task_work(&req->task_work, io_req_task_submit);
percpu_ref_get(&req->ctx->refs);
ret = io_req_task_work_add(req);
if (unlikely(ret)) {
struct task_struct *tsk;
init_task_work(&req->task_work, io_req_task_cancel);
tsk = io_wq_get_task(req->ctx->io_wq);
task_work_add(tsk, &req->task_work, TWA_NONE);
wake_up_process(tsk);
}
}
static inline void io_queue_next(struct io_kiocb *req)
{
struct io_kiocb *nxt = io_req_find_next(req);
if (nxt)
io_req_task_queue(nxt);
}
static void io_free_req(struct io_kiocb *req)
{
io_queue_next(req);
__io_free_req(req);
}
struct req_batch {
void *reqs[IO_IOPOLL_BATCH];
int to_free;
struct task_struct *task;
int task_refs;
};
static inline void io_init_req_batch(struct req_batch *rb)
{
rb->to_free = 0;
rb->task_refs = 0;
rb->task = NULL;
}
static void __io_req_free_batch_flush(struct io_ring_ctx *ctx,
struct req_batch *rb)
{
kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
percpu_ref_put_many(&ctx->refs, rb->to_free);
rb->to_free = 0;
}
static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
struct req_batch *rb)
{
if (rb->to_free)
__io_req_free_batch_flush(ctx, rb);
if (rb->task) {
struct io_uring_task *tctx = rb->task->io_uring;
percpu_counter_sub(&tctx->inflight, rb->task_refs);
if (atomic_read(&tctx->in_idle))
wake_up(&tctx->wait);
put_task_struct_many(rb->task, rb->task_refs);
rb->task = NULL;
}
}
static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
{
if (unlikely(io_is_fallback_req(req))) {
io_free_req(req);
return;
}
io_queue_next(req);
if (req->task != rb->task) {
if (rb->task) {
struct io_uring_task *tctx = rb->task->io_uring;
percpu_counter_sub(&tctx->inflight, rb->task_refs);
if (atomic_read(&tctx->in_idle))
wake_up(&tctx->wait);
put_task_struct_many(rb->task, rb->task_refs);
}
rb->task = req->task;
rb->task_refs = 0;
}
rb->task_refs++;
io_dismantle_req(req);
rb->reqs[rb->to_free++] = req;
if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
__io_req_free_batch_flush(req->ctx, rb);
}
/*
* Drop reference to request, return next in chain (if there is one) if this
* was the last reference to this request.
*/
static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
{
struct io_kiocb *nxt = NULL;
if (refcount_dec_and_test(&req->refs)) {
nxt = io_req_find_next(req);
__io_free_req(req);
}
return nxt;
}
static void io_put_req(struct io_kiocb *req)
{
if (refcount_dec_and_test(&req->refs))
io_free_req(req);
}
static void io_put_req_deferred_cb(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
io_free_req(req);
}
static void io_free_req_deferred(struct io_kiocb *req)
{
int ret;
init_task_work(&req->task_work, io_put_req_deferred_cb);
ret = io_req_task_work_add(req);
if (unlikely(ret)) {
struct task_struct *tsk;
tsk = io_wq_get_task(req->ctx->io_wq);
task_work_add(tsk, &req->task_work, TWA_NONE);
wake_up_process(tsk);
}
}
static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
{
if (refcount_sub_and_test(refs, &req->refs))
io_free_req_deferred(req);
}
static struct io_wq_work *io_steal_work(struct io_kiocb *req)
{
struct io_kiocb *nxt;
/*
* A ref is owned by io-wq in which context we're. So, if that's the
* last one, it's safe to steal next work. False negatives are Ok,
* it just will be re-punted async in io_put_work()
*/
if (refcount_read(&req->refs) != 1)
return NULL;
nxt = io_req_find_next(req);
return nxt ? &nxt->work : NULL;
}
static void io_double_put_req(struct io_kiocb *req)
{
/* drop both submit and complete references */
if (refcount_sub_and_test(2, &req->refs))
io_free_req(req);
}
static unsigned io_cqring_events(struct io_ring_ctx *ctx)
{
/* See comment at the top of this file */
smp_rmb();
return __io_cqring_events(ctx);
}
static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
/* make sure SQ entry isn't read before tail */
return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
}
static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
{
unsigned int cflags;
cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
cflags |= IORING_CQE_F_BUFFER;
req->flags &= ~REQ_F_BUFFER_SELECTED;
kfree(kbuf);
return cflags;
}
static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
{
struct io_buffer *kbuf;
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
return io_put_kbuf(req, kbuf);
}
static inline bool io_run_task_work(void)
{
/*
* Not safe to run on exiting task, and the task_work handling will
* not add work to such a task.
*/
if (unlikely(current->flags & PF_EXITING))
return false;
if (current->task_works) {
__set_current_state(TASK_RUNNING);
task_work_run();
return true;
}
return false;
}
static void io_iopoll_queue(struct list_head *again)
{
struct io_kiocb *req;
do {
req = list_first_entry(again, struct io_kiocb, inflight_entry);
list_del(&req->inflight_entry);
__io_complete_rw(req, -EAGAIN, 0, NULL);
} while (!list_empty(again));
}
/*
* Find and free completed poll iocbs
*/
static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
struct list_head *done)
{
struct req_batch rb;
struct io_kiocb *req;
LIST_HEAD(again);
/* order with ->result store in io_complete_rw_iopoll() */
smp_rmb();
io_init_req_batch(&rb);
while (!list_empty(done)) {
int cflags = 0;
req = list_first_entry(done, struct io_kiocb, inflight_entry);
if (READ_ONCE(req->result) == -EAGAIN) {
req->result = 0;
req->iopoll_completed = 0;
list_move_tail(&req->inflight_entry, &again);
continue;
}
list_del(&req->inflight_entry);
if (req->flags & REQ_F_BUFFER_SELECTED)
cflags = io_put_rw_kbuf(req);
__io_cqring_fill_event(req, req->result, cflags);
(*nr_events)++;
if (refcount_dec_and_test(&req->refs))
io_req_free_batch(&rb, req);
}
io_commit_cqring(ctx);
io_cqring_ev_posted_iopoll(ctx);
io_req_free_batch_finish(ctx, &rb);
if (!list_empty(&again))
io_iopoll_queue(&again);
}
static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
long min)
{
struct io_kiocb *req, *tmp;
LIST_HEAD(done);
bool spin;
int ret;
/*
* Only spin for completions if we don't have multiple devices hanging
* off our complete list, and we're under the requested amount.
*/
spin = !ctx->poll_multi_file && *nr_events < min;
ret = 0;
list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
struct kiocb *kiocb = &req->rw.kiocb;
/*
* Move completed and retryable entries to our local lists.
* If we find a request that requires polling, break out
* and complete those lists first, if we have entries there.
*/
if (READ_ONCE(req->iopoll_completed)) {
list_move_tail(&req->inflight_entry, &done);
continue;
}
if (!list_empty(&done))
break;
ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
if (ret < 0)
break;
/* iopoll may have completed current req */
if (READ_ONCE(req->iopoll_completed))
list_move_tail(&req->inflight_entry, &done);
if (ret && spin)
spin = false;
ret = 0;
}
if (!list_empty(&done))
io_iopoll_complete(ctx, nr_events, &done);
return ret;
}
/*
* Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
* non-spinning poll check - we'll still enter the driver poll loop, but only
* as a non-spinning completion check.
*/
static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
long min)
{
while (!list_empty(&ctx->iopoll_list) && !need_resched()) {
int ret;
ret = io_do_iopoll(ctx, nr_events, min);
if (ret < 0)
return ret;
if (*nr_events >= min)
return 0;
}
return 1;
}
/*
* We can't just wait for polled events to come to us, we have to actively
* find and complete them.
*/
static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
{
if (!(ctx->flags & IORING_SETUP_IOPOLL))
return;
mutex_lock(&ctx->uring_lock);
while (!list_empty(&ctx->iopoll_list)) {
unsigned int nr_events = 0;
io_do_iopoll(ctx, &nr_events, 0);
/* let it sleep and repeat later if can't complete a request */
if (nr_events == 0)
break;
/*
* Ensure we allow local-to-the-cpu processing to take place,
* in this case we need to ensure that we reap all events.
* Also let task_work, etc. to progress by releasing the mutex
*/
if (need_resched()) {
mutex_unlock(&ctx->uring_lock);
cond_resched();
mutex_lock(&ctx->uring_lock);
}
}
mutex_unlock(&ctx->uring_lock);
}
static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
{
unsigned int nr_events = 0;
int iters = 0, ret = 0;
/*
* We disallow the app entering submit/complete with polling, but we
* still need to lock the ring to prevent racing with polled issue
* that got punted to a workqueue.
*/
mutex_lock(&ctx->uring_lock);
do {
/*
* Don't enter poll loop if we already have events pending.
* If we do, we can potentially be spinning for commands that
* already triggered a CQE (eg in error).
*/
if (test_bit(0, &ctx->cq_check_overflow))
__io_cqring_overflow_flush(ctx, false, NULL, NULL);
if (io_cqring_events(ctx))
break;
/*
* If a submit got punted to a workqueue, we can have the
* application entering polling for a command before it gets
* issued. That app will hold the uring_lock for the duration
* of the poll right here, so we need to take a breather every
* now and then to ensure that the issue has a chance to add
* the poll to the issued list. Otherwise we can spin here
* forever, while the workqueue is stuck trying to acquire the
* very same mutex.
*/
if (!(++iters & 7)) {
mutex_unlock(&ctx->uring_lock);
io_run_task_work();
mutex_lock(&ctx->uring_lock);
}
ret = io_iopoll_getevents(ctx, &nr_events, min);
if (ret <= 0)
break;
ret = 0;
} while (min && !nr_events && !need_resched());
mutex_unlock(&ctx->uring_lock);
return ret;
}
static void kiocb_end_write(struct io_kiocb *req)
{
/*
* Tell lockdep we inherited freeze protection from submission
* thread.
*/
if (req->flags & REQ_F_ISREG) {
struct inode *inode = file_inode(req->file);
__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
}
file_end_write(req->file);
}
static void io_complete_rw_common(struct kiocb *kiocb, long res,
struct io_comp_state *cs)
{
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
int cflags = 0;
if (kiocb->ki_flags & IOCB_WRITE)
kiocb_end_write(req);
if (res != req->result)
req_set_fail_links(req);
if (req->flags & REQ_F_BUFFER_SELECTED)
cflags = io_put_rw_kbuf(req);
__io_req_complete(req, res, cflags, cs);
}
#ifdef CONFIG_BLOCK
static bool io_resubmit_prep(struct io_kiocb *req, int error)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
ssize_t ret = -ECANCELED;
struct iov_iter iter;
int rw;
if (error) {
ret = error;
goto end_req;
}
switch (req->opcode) {
case IORING_OP_READV:
case IORING_OP_READ_FIXED:
case IORING_OP_READ:
rw = READ;
break;
case IORING_OP_WRITEV:
case IORING_OP_WRITE_FIXED:
case IORING_OP_WRITE:
rw = WRITE;
break;
default:
printk_once(KERN_WARNING "io_uring: bad opcode in resubmit %d\n",
req->opcode);
goto end_req;
}
if (!req->async_data) {
ret = io_import_iovec(rw, req, &iovec, &iter, false);
if (ret < 0)
goto end_req;
ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false);
if (!ret)
return true;
kfree(iovec);
} else {
return true;
}
end_req:
req_set_fail_links(req);
return false;
}
#endif
static bool io_rw_reissue(struct io_kiocb *req, long res)
{
#ifdef CONFIG_BLOCK
umode_t mode = file_inode(req->file)->i_mode;
int ret;
if (!S_ISBLK(mode) && !S_ISREG(mode))
return false;
if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
return false;
lockdep_assert_held(&req->ctx->uring_lock);
ret = io_sq_thread_acquire_mm_files(req->ctx, req);
if (io_resubmit_prep(req, ret)) {
refcount_inc(&req->refs);
io_queue_async_work(req);
return true;
}
#endif
return false;
}
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
struct io_comp_state *cs)
{
if (!io_rw_reissue(req, res))
io_complete_rw_common(&req->rw.kiocb, res, cs);
}
static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
{
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
__io_complete_rw(req, res, res2, NULL);
}
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
{
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
if (kiocb->ki_flags & IOCB_WRITE)
kiocb_end_write(req);
if (res != -EAGAIN && res != req->result)
req_set_fail_links(req);
WRITE_ONCE(req->result, res);
/* order with io_poll_complete() checking ->result */
smp_wmb();
WRITE_ONCE(req->iopoll_completed, 1);
}
/*
* After the iocb has been issued, it's safe to be found on the poll list.
* Adding the kiocb to the list AFTER submission ensures that we don't
* find it from a io_iopoll_getevents() thread before the issuer is done
* accessing the kiocb cookie.
*/
static void io_iopoll_req_issued(struct io_kiocb *req, bool in_async)
{
struct io_ring_ctx *ctx = req->ctx;
/*
* Track whether we have multiple files in our lists. This will impact
* how we do polling eventually, not spinning if we're on potentially
* different devices.
*/
if (list_empty(&ctx->iopoll_list)) {
ctx->poll_multi_file = false;
} else if (!ctx->poll_multi_file) {
struct io_kiocb *list_req;
list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
inflight_entry);
if (list_req->file != req->file)
ctx->poll_multi_file = true;
}
/*
* For fast devices, IO may have already completed. If it has, add
* it to the front so we find it first.
*/
if (READ_ONCE(req->iopoll_completed))
list_add(&req->inflight_entry, &ctx->iopoll_list);
else
list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
/*
* If IORING_SETUP_SQPOLL is enabled, sqes are either handled in sq thread
* task context or in io worker task context. If current task context is
* sq thread, we don't need to check whether should wake up sq thread.
*/
if (in_async && (ctx->flags & IORING_SETUP_SQPOLL) &&
wq_has_sleeper(&ctx->sq_data->wait))
wake_up(&ctx->sq_data->wait);
}
static inline void __io_state_file_put(struct io_submit_state *state)
{
fput_many(state->file, state->file_refs);
state->file_refs = 0;
}
static inline void io_state_file_put(struct io_submit_state *state)
{
if (state->file_refs)
__io_state_file_put(state);
}
/*
* Get as many references to a file as we have IOs left in this submission,
* assuming most submissions are for one file, or at least that each file
* has more than one submission.
*/
static struct file *__io_file_get(struct io_submit_state *state, int fd)
{
if (!state)
return fget(fd);
if (state->file_refs) {
if (state->fd == fd) {
state->file_refs--;
return state->file;
}
__io_state_file_put(state);
}
state->file = fget_many(fd, state->ios_left);
if (unlikely(!state->file))
return NULL;
state->fd = fd;
state->file_refs = state->ios_left - 1;
return state->file;
}
static bool io_bdev_nowait(struct block_device *bdev)
{
return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
}
/*
* If we tracked the file through the SCM inflight mechanism, we could support
* any file. For now, just ensure that anything potentially problematic is done
* inline.
*/
static bool io_file_supports_async(struct file *file, int rw)
{
umode_t mode = file_inode(file)->i_mode;
if (S_ISBLK(mode)) {
if (IS_ENABLED(CONFIG_BLOCK) &&
io_bdev_nowait(I_BDEV(file->f_mapping->host)))
return true;
return false;
}
if (S_ISCHR(mode) || S_ISSOCK(mode))
return true;
if (S_ISREG(mode)) {
if (IS_ENABLED(CONFIG_BLOCK) &&
io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
file->f_op != &io_uring_fops)
return true;
return false;
}
/* any ->read/write should understand O_NONBLOCK */
if (file->f_flags & O_NONBLOCK)
return true;
if (!(file->f_mode & FMODE_NOWAIT))
return false;
if (rw == READ)
return file->f_op->read_iter != NULL;
return file->f_op->write_iter != NULL;
}
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_ring_ctx *ctx = req->ctx;
struct kiocb *kiocb = &req->rw.kiocb;
unsigned ioprio;
int ret;
if (S_ISREG(file_inode(req->file)->i_mode))
req->flags |= REQ_F_ISREG;
kiocb->ki_pos = READ_ONCE(sqe->off);
if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
req->flags |= REQ_F_CUR_POS;
kiocb->ki_pos = req->file->f_pos;
}
kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
if (unlikely(ret))
return ret;
ioprio = READ_ONCE(sqe->ioprio);
if (ioprio) {
ret = ioprio_check_cap(ioprio);
if (ret)
return ret;
kiocb->ki_ioprio = ioprio;
} else
kiocb->ki_ioprio = get_current_ioprio();
/* don't allow async punt if RWF_NOWAIT was requested */
if (kiocb->ki_flags & IOCB_NOWAIT)
req->flags |= REQ_F_NOWAIT;
if (ctx->flags & IORING_SETUP_IOPOLL) {
if (!(kiocb->ki_flags & IOCB_DIRECT) ||
!kiocb->ki_filp->f_op->iopoll)
return -EOPNOTSUPP;
kiocb->ki_flags |= IOCB_HIPRI;
kiocb->ki_complete = io_complete_rw_iopoll;
req->iopoll_completed = 0;
} else {
if (kiocb->ki_flags & IOCB_HIPRI)
return -EINVAL;
kiocb->ki_complete = io_complete_rw;
}
req->rw.addr = READ_ONCE(sqe->addr);
req->rw.len = READ_ONCE(sqe->len);
req->buf_index = READ_ONCE(sqe->buf_index);
return 0;
}
static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
{
switch (ret) {
case -EIOCBQUEUED:
break;
case -ERESTARTSYS:
case -ERESTARTNOINTR:
case -ERESTARTNOHAND:
case -ERESTART_RESTARTBLOCK:
/*
* We can't just restart the syscall, since previously
* submitted sqes may already be in progress. Just fail this
* IO with EINTR.
*/
ret = -EINTR;
fallthrough;
default:
kiocb->ki_complete(kiocb, ret, 0);
}
}
static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
struct io_comp_state *cs)
{
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
struct io_async_rw *io = req->async_data;
/* add previously done IO, if any */
if (io && io->bytes_done > 0) {
if (ret < 0)
ret = io->bytes_done;
else
ret += io->bytes_done;
}
if (req->flags & REQ_F_CUR_POS)
req->file->f_pos = kiocb->ki_pos;
if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
__io_complete_rw(req, ret, 0, cs);
else
io_rw_done(kiocb, ret);
}
static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
struct iov_iter *iter)
{
struct io_ring_ctx *ctx = req->ctx;
size_t len = req->rw.len;
struct io_mapped_ubuf *imu;
u16 index, buf_index = req->buf_index;
size_t offset;
u64 buf_addr;
if (unlikely(buf_index >= ctx->nr_user_bufs))
return -EFAULT;
index = array_index_nospec(buf_index, ctx->nr_user_bufs);
imu = &ctx->user_bufs[index];
buf_addr = req->rw.addr;
/* overflow */
if (buf_addr + len < buf_addr)
return -EFAULT;
/* not inside the mapped region */
if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
return -EFAULT;
/*
* May not be a start of buffer, set size appropriately
* and advance us to the beginning.
*/
offset = buf_addr - imu->ubuf;
iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
if (offset) {
/*
* Don't use iov_iter_advance() here, as it's really slow for
* using the latter parts of a big fixed buffer - it iterates
* over each segment manually. We can cheat a bit here, because
* we know that:
*
* 1) it's a BVEC iter, we set it up
* 2) all bvecs are PAGE_SIZE in size, except potentially the
* first and last bvec
*
* So just find our index, and adjust the iterator afterwards.
* If the offset is within the first bvec (or the whole first
* bvec, just use iov_iter_advance(). This makes it easier
* since we can just skip the first segment, which may not
* be PAGE_SIZE aligned.
*/
const struct bio_vec *bvec = imu->bvec;
if (offset <= bvec->bv_len) {
iov_iter_advance(iter, offset);
} else {
unsigned long seg_skip;
/* skip first vec */
offset -= bvec->bv_len;
seg_skip = 1 + (offset >> PAGE_SHIFT);
iter->bvec = bvec + seg_skip;
iter->nr_segs -= seg_skip;
iter->count -= bvec->bv_len + offset;
iter->iov_offset = offset & ~PAGE_MASK;
}
}
return len;
}
static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
{
if (needs_lock)
mutex_unlock(&ctx->uring_lock);
}
static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
{
/*
* "Normal" inline submissions always hold the uring_lock, since we
* grab it from the system call. Same is true for the SQPOLL offload.
* The only exception is when we've detached the request and issue it
* from an async worker thread, grab the lock for that case.
*/
if (needs_lock)
mutex_lock(&ctx->uring_lock);
}
static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
int bgid, struct io_buffer *kbuf,
bool needs_lock)
{
struct io_buffer *head;
if (req->flags & REQ_F_BUFFER_SELECTED)
return kbuf;
io_ring_submit_lock(req->ctx, needs_lock);
lockdep_assert_held(&req->ctx->uring_lock);
head = idr_find(&req->ctx->io_buffer_idr, bgid);
if (head) {
if (!list_empty(&head->list)) {
kbuf = list_last_entry(&head->list, struct io_buffer,
list);
list_del(&kbuf->list);
} else {
kbuf = head;
idr_remove(&req->ctx->io_buffer_idr, bgid);
}
if (*len > kbuf->len)
*len = kbuf->len;
} else {
kbuf = ERR_PTR(-ENOBUFS);
}
io_ring_submit_unlock(req->ctx, needs_lock);
return kbuf;
}
static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
bool needs_lock)
{
struct io_buffer *kbuf;
u16 bgid;
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
bgid = req->buf_index;
kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
if (IS_ERR(kbuf))
return kbuf;
req->rw.addr = (u64) (unsigned long) kbuf;
req->flags |= REQ_F_BUFFER_SELECTED;
return u64_to_user_ptr(kbuf->addr);
}
#ifdef CONFIG_COMPAT
static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
bool needs_lock)
{
struct compat_iovec __user *uiov;
compat_ssize_t clen;
void __user *buf;
ssize_t len;
uiov = u64_to_user_ptr(req->rw.addr);
if (!access_ok(uiov, sizeof(*uiov)))
return -EFAULT;
if (__get_user(clen, &uiov->iov_len))
return -EFAULT;
if (clen < 0)
return -EINVAL;
len = clen;
buf = io_rw_buffer_select(req, &len, needs_lock);
if (IS_ERR(buf))
return PTR_ERR(buf);
iov[0].iov_base = buf;
iov[0].iov_len = (compat_size_t) len;
return 0;
}
#endif
static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
bool needs_lock)
{
struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
void __user *buf;
ssize_t len;
if (copy_from_user(iov, uiov, sizeof(*uiov)))
return -EFAULT;
len = iov[0].iov_len;
if (len < 0)
return -EINVAL;
buf = io_rw_buffer_select(req, &len, needs_lock);
if (IS_ERR(buf))
return PTR_ERR(buf);
iov[0].iov_base = buf;
iov[0].iov_len = len;
return 0;
}
static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
bool needs_lock)
{
if (req->flags & REQ_F_BUFFER_SELECTED) {
struct io_buffer *kbuf;
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
iov[0].iov_len = kbuf->len;
return 0;
}
if (req->rw.len != 1)
return -EINVAL;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
return io_compat_import(req, iov, needs_lock);
#endif
return __io_iov_buffer_select(req, iov, needs_lock);
}
static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
struct iovec **iovec, struct iov_iter *iter,
bool needs_lock)
{
void __user *buf = u64_to_user_ptr(req->rw.addr);
size_t sqe_len = req->rw.len;
ssize_t ret;
u8 opcode;
opcode = req->opcode;
if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
*iovec = NULL;
return io_import_fixed(req, rw, iter);
}
/* buffer index only valid with fixed read/write, or buffer select */
if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
return -EINVAL;
if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
if (req->flags & REQ_F_BUFFER_SELECT) {
buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
if (IS_ERR(buf))
return PTR_ERR(buf);
req->rw.len = sqe_len;
}
ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
*iovec = NULL;
return ret;
}
if (req->flags & REQ_F_BUFFER_SELECT) {
ret = io_iov_buffer_select(req, *iovec, needs_lock);
if (!ret) {
ret = (*iovec)->iov_len;
iov_iter_init(iter, rw, *iovec, 1, ret);
}
*iovec = NULL;
return ret;
}
return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
req->ctx->compat);
}
static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
{
return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
}
/*
* For files that don't have ->read_iter() and ->write_iter(), handle them
* by looping over ->read() or ->write() manually.
*/
static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
{
struct kiocb *kiocb = &req->rw.kiocb;
struct file *file = req->file;
ssize_t ret = 0;
/*
* Don't support polled IO through this interface, and we can't
* support non-blocking either. For the latter, this just causes
* the kiocb to be handled from an async context.
*/
if (kiocb->ki_flags & IOCB_HIPRI)
return -EOPNOTSUPP;
if (kiocb->ki_flags & IOCB_NOWAIT)
return -EAGAIN;
while (iov_iter_count(iter)) {
struct iovec iovec;
ssize_t nr;
if (!iov_iter_is_bvec(iter)) {
iovec = iov_iter_iovec(iter);
} else {
iovec.iov_base = u64_to_user_ptr(req->rw.addr);
iovec.iov_len = req->rw.len;
}
if (rw == READ) {
nr = file->f_op->read(file, iovec.iov_base,
iovec.iov_len, io_kiocb_ppos(kiocb));
} else {
nr = file->f_op->write(file, iovec.iov_base,
iovec.iov_len, io_kiocb_ppos(kiocb));
}
if (nr < 0) {
if (!ret)
ret = nr;
break;
}
ret += nr;
if (nr != iovec.iov_len)
break;
req->rw.len -= nr;
req->rw.addr += nr;
iov_iter_advance(iter, nr);
}
return ret;
}
static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
const struct iovec *fast_iov, struct iov_iter *iter)
{
struct io_async_rw *rw = req->async_data;
memcpy(&rw->iter, iter, sizeof(*iter));
rw->free_iovec = iovec;
rw->bytes_done = 0;
/* can only be fixed buffers, no need to do anything */
if (iov_iter_is_bvec(iter))
return;
if (!iovec) {
unsigned iov_off = 0;
rw->iter.iov = rw->fast_iov;
if (iter->iov != fast_iov) {
iov_off = iter->iov - fast_iov;
rw->iter.iov += iov_off;
}
if (rw->fast_iov != fast_iov)
memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
sizeof(struct iovec) * iter->nr_segs);
} else {
req->flags |= REQ_F_NEED_CLEANUP;
}
}
static inline int __io_alloc_async_data(struct io_kiocb *req)
{
WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
return req->async_data == NULL;
}
static int io_alloc_async_data(struct io_kiocb *req)
{
if (!io_op_defs[req->opcode].needs_async_data)
return 0;
return __io_alloc_async_data(req);
}
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
const struct iovec *fast_iov,
struct iov_iter *iter, bool force)
{
if (!force && !io_op_defs[req->opcode].needs_async_data)
return 0;
if (!req->async_data) {
if (__io_alloc_async_data(req))
return -ENOMEM;
io_req_map_rw(req, iovec, fast_iov, iter);
}
return 0;
}
static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
{
struct io_async_rw *iorw = req->async_data;
struct iovec *iov = iorw->fast_iov;
ssize_t ret;
ret = io_import_iovec(rw, req, &iov, &iorw->iter, false);
if (unlikely(ret < 0))
return ret;
iorw->bytes_done = 0;
iorw->free_iovec = iov;
if (iov)
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
ssize_t ret;
ret = io_prep_rw(req, sqe);
if (ret)
return ret;
if (unlikely(!(req->file->f_mode & FMODE_READ)))
return -EBADF;
/* either don't need iovec imported or already have it */
if (!req->async_data)
return 0;
return io_rw_prep_async(req, READ);
}
/*
* This is our waitqueue callback handler, registered through lock_page_async()
* when we initially tried to do the IO with the iocb armed our waitqueue.
* This gets called when the page is unlocked, and we generally expect that to
* happen when the page IO is completed and the page is now uptodate. This will
* queue a task_work based retry of the operation, attempting to copy the data
* again. If the latter fails because the page was NOT uptodate, then we will
* do a thread based blocking retry of the operation. That's the unexpected
* slow path.
*/
static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
int sync, void *arg)
{
struct wait_page_queue *wpq;
struct io_kiocb *req = wait->private;
struct wait_page_key *key = arg;
int ret;
wpq = container_of(wait, struct wait_page_queue, wait);
if (!wake_page_match(wpq, key))
return 0;
req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
list_del_init(&wait->entry);
init_task_work(&req->task_work, io_req_task_submit);
percpu_ref_get(&req->ctx->refs);
/* submit ref gets dropped, acquire a new one */
refcount_inc(&req->refs);
ret = io_req_task_work_add(req);
if (unlikely(ret)) {
struct task_struct *tsk;
/* queue just for cancelation */
init_task_work(&req->task_work, io_req_task_cancel);
tsk = io_wq_get_task(req->ctx->io_wq);
task_work_add(tsk, &req->task_work, TWA_NONE);
wake_up_process(tsk);
}
return 1;
}
/*
* This controls whether a given IO request should be armed for async page
* based retry. If we return false here, the request is handed to the async
* worker threads for retry. If we're doing buffered reads on a regular file,
* we prepare a private wait_page_queue entry and retry the operation. This
* will either succeed because the page is now uptodate and unlocked, or it
* will register a callback when the page is unlocked at IO completion. Through
* that callback, io_uring uses task_work to setup a retry of the operation.
* That retry will attempt the buffered read again. The retry will generally
* succeed, or in rare cases where it fails, we then fall back to using the
* async worker threads for a blocking retry.
*/
static bool io_rw_should_retry(struct io_kiocb *req)
{
struct io_async_rw *rw = req->async_data;
struct wait_page_queue *wait = &rw->wpq;
struct kiocb *kiocb = &req->rw.kiocb;
/* never retry for NOWAIT, we just complete with -EAGAIN */
if (req->flags & REQ_F_NOWAIT)
return false;
/* Only for buffered IO */
if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
return false;
/*
* just use poll if we can, and don't attempt if the fs doesn't
* support callback based unlocks
*/
if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
return false;
wait->wait.func = io_async_buf_func;
wait->wait.private = req;
wait->wait.flags = 0;
INIT_LIST_HEAD(&wait->wait.entry);
kiocb->ki_flags |= IOCB_WAITQ;
kiocb->ki_flags &= ~IOCB_NOWAIT;
kiocb->ki_waitq = wait;
return true;
}
static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
{
if (req->file->f_op->read_iter)
return call_read_iter(req->file, &req->rw.kiocb, iter);
else if (req->file->f_op->read)
return loop_rw_iter(READ, req, iter);
else
return -EINVAL;
}
static int io_read(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct kiocb *kiocb = &req->rw.kiocb;
struct iov_iter __iter, *iter = &__iter;
struct io_async_rw *rw = req->async_data;
ssize_t io_size, ret, ret2;
bool no_async;
if (rw) {
iter = &rw->iter;
iovec = NULL;
} else {
ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
if (ret < 0)
return ret;
}
io_size = iov_iter_count(iter);
req->result = io_size;
ret = 0;
/* Ensure we clear previously set non-block flag */
if (!force_nonblock)
kiocb->ki_flags &= ~IOCB_NOWAIT;
else
kiocb->ki_flags |= IOCB_NOWAIT;
/* If the file doesn't support async, just async punt */
no_async = force_nonblock && !io_file_supports_async(req->file, READ);
if (no_async)
goto copy_iov;
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size);
if (unlikely(ret))
goto out_free;
ret = io_iter_do_read(req, iter);
if (!ret) {
goto done;
} else if (ret == -EIOCBQUEUED) {
ret = 0;
goto out_free;
} else if (ret == -EAGAIN) {
/* IOPOLL retry should happen for io-wq threads */
if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
goto done;
/* no retry on NONBLOCK marked file */
if (req->file->f_flags & O_NONBLOCK)
goto done;
/* some cases will consume bytes even on error returns */
iov_iter_revert(iter, io_size - iov_iter_count(iter));
ret = 0;
goto copy_iov;
} else if (ret < 0) {
/* make sure -ERESTARTSYS -> -EINTR is done */
goto done;
}
/* read it all, or we did blocking attempt. no retry. */
if (!iov_iter_count(iter) || !force_nonblock ||
(req->file->f_flags & O_NONBLOCK) || !(req->flags & REQ_F_ISREG))
goto done;
io_size -= ret;
copy_iov:
ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
if (ret2) {
ret = ret2;
goto out_free;
}
if (no_async)
return -EAGAIN;
rw = req->async_data;
/* it's copied and will be cleaned with ->io */
iovec = NULL;
/* now use our persistent iterator, if we aren't already */
iter = &rw->iter;
retry:
rw->bytes_done += ret;
/* if we can retry, do so with the callbacks armed */
if (!io_rw_should_retry(req)) {
kiocb->ki_flags &= ~IOCB_WAITQ;
return -EAGAIN;
}
/*
* Now retry read with the IOCB_WAITQ parts set in the iocb. If we
* get -EIOCBQUEUED, then we'll get a notification when the desired
* page gets unlocked. We can also get a partial read here, and if we
* do, then just retry at the new offset.
*/
ret = io_iter_do_read(req, iter);
if (ret == -EIOCBQUEUED) {
ret = 0;
goto out_free;
} else if (ret > 0 && ret < io_size) {
/* we got some bytes, but not all. retry. */
goto retry;
}
done:
kiocb_done(kiocb, ret, cs);
ret = 0;
out_free:
/* it's reportedly faster than delegating the null check to kfree() */
if (iovec)
kfree(iovec);
return ret;
}
static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
ssize_t ret;
ret = io_prep_rw(req, sqe);
if (ret)
return ret;
if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
return -EBADF;
/* either don't need iovec imported or already have it */
if (!req->async_data)
return 0;
return io_rw_prep_async(req, WRITE);
}
static int io_write(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct kiocb *kiocb = &req->rw.kiocb;
struct iov_iter __iter, *iter = &__iter;
struct io_async_rw *rw = req->async_data;
ssize_t ret, ret2, io_size;
if (rw) {
iter = &rw->iter;
iovec = NULL;
} else {
ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
if (ret < 0)
return ret;
}
io_size = iov_iter_count(iter);
req->result = io_size;
/* Ensure we clear previously set non-block flag */
if (!force_nonblock)
kiocb->ki_flags &= ~IOCB_NOWAIT;
else
kiocb->ki_flags |= IOCB_NOWAIT;
/* If the file doesn't support async, just async punt */
if (force_nonblock && !io_file_supports_async(req->file, WRITE))
goto copy_iov;
/* file path doesn't support NOWAIT for non-direct_IO */
if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
(req->flags & REQ_F_ISREG))
goto copy_iov;
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), io_size);
if (unlikely(ret))
goto out_free;
/*
* Open-code file_start_write here to grab freeze protection,
* which will be released by another thread in
* io_complete_rw(). Fool lockdep by telling it the lock got
* released so that it doesn't complain about the held lock when
* we return to userspace.
*/
if (req->flags & REQ_F_ISREG) {
sb_start_write(file_inode(req->file)->i_sb);
__sb_writers_release(file_inode(req->file)->i_sb,
SB_FREEZE_WRITE);
}
kiocb->ki_flags |= IOCB_WRITE;
if (req->file->f_op->write_iter)
ret2 = call_write_iter(req->file, kiocb, iter);
else if (req->file->f_op->write)
ret2 = loop_rw_iter(WRITE, req, iter);
else
ret2 = -EINVAL;
/*
* Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
* retry them without IOCB_NOWAIT.
*/
if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
ret2 = -EAGAIN;
/* no retry on NONBLOCK marked file */
if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK))
goto done;
if (!force_nonblock || ret2 != -EAGAIN) {
/* IOPOLL retry should happen for io-wq threads */
if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
goto copy_iov;
done:
kiocb_done(kiocb, ret2, cs);
} else {
copy_iov:
/* some cases will consume bytes even on error returns */
iov_iter_revert(iter, io_size - iov_iter_count(iter));
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
if (!ret)
return -EAGAIN;
}
out_free:
/* it's reportedly faster than delegating the null check to kfree() */
if (iovec)
kfree(iovec);
return ret;
}
static int io_renameat_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_rename *ren = &req->rename;
const char __user *oldf, *newf;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
ren->old_dfd = READ_ONCE(sqe->fd);
oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
ren->new_dfd = READ_ONCE(sqe->len);
ren->flags = READ_ONCE(sqe->rename_flags);
ren->oldpath = getname(oldf);
if (IS_ERR(ren->oldpath))
return PTR_ERR(ren->oldpath);
ren->newpath = getname(newf);
if (IS_ERR(ren->newpath)) {
putname(ren->oldpath);
return PTR_ERR(ren->newpath);
}
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
static int io_renameat(struct io_kiocb *req, bool force_nonblock)
{
struct io_rename *ren = &req->rename;
int ret;
if (force_nonblock)
return -EAGAIN;
ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,
ren->newpath, ren->flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_unlinkat_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_unlink *un = &req->unlink;
const char __user *fname;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
un->dfd = READ_ONCE(sqe->fd);
un->flags = READ_ONCE(sqe->unlink_flags);
if (un->flags & ~AT_REMOVEDIR)
return -EINVAL;
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
un->filename = getname(fname);
if (IS_ERR(un->filename))
return PTR_ERR(un->filename);
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
static int io_unlinkat(struct io_kiocb *req, bool force_nonblock)
{
struct io_unlink *un = &req->unlink;
int ret;
if (force_nonblock)
return -EAGAIN;
if (un->flags & AT_REMOVEDIR)
ret = do_rmdir(un->dfd, un->filename);
else
ret = do_unlinkat(un->dfd, un->filename);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_shutdown_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
#if defined(CONFIG_NET)
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags ||
sqe->buf_index)
return -EINVAL;
req->shutdown.how = READ_ONCE(sqe->len);
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int io_shutdown(struct io_kiocb *req, bool force_nonblock)
{
#if defined(CONFIG_NET)
struct socket *sock;
int ret;
if (force_nonblock)
return -EAGAIN;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = __sys_shutdown_sock(sock, req->shutdown.how);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int __io_splice_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_splice* sp = &req->splice;
unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
sp->file_in = NULL;
sp->len = READ_ONCE(sqe->len);
sp->flags = READ_ONCE(sqe->splice_flags);
if (unlikely(sp->flags & ~valid_flags))
return -EINVAL;
sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in),
(sp->flags & SPLICE_F_FD_IN_FIXED));
if (!sp->file_in)
return -EBADF;
req->flags |= REQ_F_NEED_CLEANUP;
if (!S_ISREG(file_inode(sp->file_in)->i_mode)) {
/*
* Splice operation will be punted aync, and here need to
* modify io_wq_work.flags, so initialize io_wq_work firstly.
*/
io_req_init_async(req);
req->work.flags |= IO_WQ_WORK_UNBOUND;
}
return 0;
}
static int io_tee_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
return -EINVAL;
return __io_splice_prep(req, sqe);
}
static int io_tee(struct io_kiocb *req, bool force_nonblock)
{
struct io_splice *sp = &req->splice;
struct file *in = sp->file_in;
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
long ret = 0;
if (force_nonblock)
return -EAGAIN;
if (sp->len)
ret = do_tee(in, out, sp->len, flags);
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret != sp->len)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_splice* sp = &req->splice;
sp->off_in = READ_ONCE(sqe->splice_off_in);
sp->off_out = READ_ONCE(sqe->off);
return __io_splice_prep(req, sqe);
}
static int io_splice(struct io_kiocb *req, bool force_nonblock)
{
struct io_splice *sp = &req->splice;
struct file *in = sp->file_in;
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
loff_t *poff_in, *poff_out;
long ret = 0;
if (force_nonblock)
return -EAGAIN;
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
if (sp->len)
ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret != sp->len)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
/*
* IORING_OP_NOP just posts a completion event, nothing else.
*/
static int io_nop(struct io_kiocb *req, struct io_comp_state *cs)
{
struct io_ring_ctx *ctx = req->ctx;
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
__io_req_complete(req, 0, 0, cs);
return 0;
}
static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_ring_ctx *ctx = req->ctx;
if (!req->file)
return -EBADF;
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
return -EINVAL;
req->sync.flags = READ_ONCE(sqe->fsync_flags);
if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
return -EINVAL;
req->sync.off = READ_ONCE(sqe->off);
req->sync.len = READ_ONCE(sqe->len);
return 0;
}
static int io_fsync(struct io_kiocb *req, bool force_nonblock)
{
loff_t end = req->sync.off + req->sync.len;
int ret;
/* fsync always requires a blocking context */
if (force_nonblock)
return -EAGAIN;
ret = vfs_fsync_range(req->file, req->sync.off,
end > 0 ? end : LLONG_MAX,
req->sync.flags & IORING_FSYNC_DATASYNC);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_fallocate_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
return -EINVAL;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
req->sync.off = READ_ONCE(sqe->off);
req->sync.len = READ_ONCE(sqe->addr);
req->sync.mode = READ_ONCE(sqe->len);
return 0;
}
static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
{
int ret;
/* fallocate always requiring blocking context */
if (force_nonblock)
return -EAGAIN;
ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
req->sync.len);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
const char __user *fname;
int ret;
if (unlikely(sqe->ioprio || sqe->buf_index))
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
/* open.how should be already initialised */
if (!(req->open.how.flags & O_PATH) && force_o_largefile())
req->open.how.flags |= O_LARGEFILE;
req->open.dfd = READ_ONCE(sqe->fd);
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
req->open.filename = getname(fname);
if (IS_ERR(req->open.filename)) {
ret = PTR_ERR(req->open.filename);
req->open.filename = NULL;
return ret;
}
req->open.nofile = rlimit(RLIMIT_NOFILE);
req->open.ignore_nonblock = false;
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
u64 flags, mode;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
mode = READ_ONCE(sqe->len);
flags = READ_ONCE(sqe->open_flags);
req->open.how = build_open_how(flags, mode);
return __io_openat_prep(req, sqe);
}
static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct open_how __user *how;
size_t len;
int ret;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
len = READ_ONCE(sqe->len);
if (len < OPEN_HOW_SIZE_VER0)
return -EINVAL;
ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
len);
if (ret)
return ret;
return __io_openat_prep(req, sqe);
}
static int io_openat2(struct io_kiocb *req, bool force_nonblock)
{
struct open_flags op;
struct file *file;
int ret;
if (force_nonblock && !req->open.ignore_nonblock)
return -EAGAIN;
ret = build_open_flags(&req->open.how, &op);
if (ret)
goto err;
ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
if (ret < 0)
goto err;
file = do_filp_open(req->open.dfd, req->open.filename, &op);
if (IS_ERR(file)) {
put_unused_fd(ret);
ret = PTR_ERR(file);
/*
* A work-around to ensure that /proc/self works that way
* that it should - if we get -EOPNOTSUPP back, then assume
* that proc_self_get_link() failed us because we're in async
* context. We should be safe to retry this from the task
* itself with force_nonblock == false set, as it should not
* block on lookup. Would be nice to know this upfront and
* avoid the async dance, but doesn't seem feasible.
*/
if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) {
req->open.ignore_nonblock = true;
refcount_inc(&req->refs);
io_req_task_queue(req);
return 0;
}
} else {
fsnotify_open(file);
fd_install(ret, file);
}
err:
putname(req->open.filename);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_openat(struct io_kiocb *req, bool force_nonblock)
{
return io_openat2(req, force_nonblock);
}
static int io_remove_buffers_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_provide_buf *p = &req->pbuf;
u64 tmp;
if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off)
return -EINVAL;
tmp = READ_ONCE(sqe->fd);
if (!tmp || tmp > USHRT_MAX)
return -EINVAL;
memset(p, 0, sizeof(*p));
p->nbufs = tmp;
p->bgid = READ_ONCE(sqe->buf_group);
return 0;
}
static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
int bgid, unsigned nbufs)
{
unsigned i = 0;
/* shouldn't happen */
if (!nbufs)
return 0;
/* the head kbuf is the list itself */
while (!list_empty(&buf->list)) {
struct io_buffer *nxt;
nxt = list_first_entry(&buf->list, struct io_buffer, list);
list_del(&nxt->list);
kfree(nxt);
if (++i == nbufs)
return i;
}
i++;
kfree(buf);
idr_remove(&ctx->io_buffer_idr, bgid);
return i;
}
static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_provide_buf *p = &req->pbuf;
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer *head;
int ret = 0;
io_ring_submit_lock(ctx, !force_nonblock);
lockdep_assert_held(&ctx->uring_lock);
ret = -ENOENT;
head = idr_find(&ctx->io_buffer_idr, p->bgid);
if (head)
ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
if (ret < 0)
req_set_fail_links(req);
/* need to hold the lock to complete IOPOLL requests */
if (ctx->flags & IORING_SETUP_IOPOLL) {
__io_req_complete(req, ret, 0, cs);
io_ring_submit_unlock(ctx, !force_nonblock);
} else {
io_ring_submit_unlock(ctx, !force_nonblock);
__io_req_complete(req, ret, 0, cs);
}
return 0;
}
static int io_provide_buffers_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_provide_buf *p = &req->pbuf;
u64 tmp;
if (sqe->ioprio || sqe->rw_flags)
return -EINVAL;
tmp = READ_ONCE(sqe->fd);
if (!tmp || tmp > USHRT_MAX)
return -E2BIG;
p->nbufs = tmp;
p->addr = READ_ONCE(sqe->addr);
p->len = READ_ONCE(sqe->len);
if (!access_ok(u64_to_user_ptr(p->addr), (p->len * p->nbufs)))
return -EFAULT;
p->bgid = READ_ONCE(sqe->buf_group);
tmp = READ_ONCE(sqe->off);
if (tmp > USHRT_MAX)
return -E2BIG;
p->bid = tmp;
return 0;
}
static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
{
struct io_buffer *buf;
u64 addr = pbuf->addr;
int i, bid = pbuf->bid;
for (i = 0; i < pbuf->nbufs; i++) {
buf = kmalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
break;
buf->addr = addr;
buf->len = pbuf->len;
buf->bid = bid;
addr += pbuf->len;
bid++;
if (!*head) {
INIT_LIST_HEAD(&buf->list);
*head = buf;
} else {
list_add_tail(&buf->list, &(*head)->list);
}
}
return i ? i : -ENOMEM;
}
static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_provide_buf *p = &req->pbuf;
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer *head, *list;
int ret = 0;
io_ring_submit_lock(ctx, !force_nonblock);
lockdep_assert_held(&ctx->uring_lock);
list = head = idr_find(&ctx->io_buffer_idr, p->bgid);
ret = io_add_buffers(p, &head);
if (ret < 0)
goto out;
if (!list) {
ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
GFP_KERNEL);
if (ret < 0) {
__io_remove_buffers(ctx, head, p->bgid, -1U);
goto out;
}
}
out:
if (ret < 0)
req_set_fail_links(req);
/* need to hold the lock to complete IOPOLL requests */
if (ctx->flags & IORING_SETUP_IOPOLL) {
__io_req_complete(req, ret, 0, cs);
io_ring_submit_unlock(ctx, !force_nonblock);
} else {
io_ring_submit_unlock(ctx, !force_nonblock);
__io_req_complete(req, ret, 0, cs);
}
return 0;
}
static int io_epoll_ctl_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
#if defined(CONFIG_EPOLL)
if (sqe->ioprio || sqe->buf_index)
return -EINVAL;
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
return -EINVAL;
req->epoll.epfd = READ_ONCE(sqe->fd);
req->epoll.op = READ_ONCE(sqe->len);
req->epoll.fd = READ_ONCE(sqe->off);
if (ep_op_has_event(req->epoll.op)) {
struct epoll_event __user *ev;
ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
return -EFAULT;
}
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
#if defined(CONFIG_EPOLL)
struct io_epoll *ie = &req->epoll;
int ret;
ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
if (force_nonblock && ret == -EAGAIN)
return -EAGAIN;
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, 0, cs);
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
if (sqe->ioprio || sqe->buf_index || sqe->off)
return -EINVAL;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
req->madvise.addr = READ_ONCE(sqe->addr);
req->madvise.len = READ_ONCE(sqe->len);
req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int io_madvise(struct io_kiocb *req, bool force_nonblock)
{
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
struct io_madvise *ma = &req->madvise;
int ret;
if (force_nonblock)
return -EAGAIN;
ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
#else
return -EOPNOTSUPP;
#endif
}
static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
if (sqe->ioprio || sqe->buf_index || sqe->addr)
return -EINVAL;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
req->fadvise.offset = READ_ONCE(sqe->off);
req->fadvise.len = READ_ONCE(sqe->len);
req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
return 0;
}
static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
{
struct io_fadvise *fa = &req->fadvise;
int ret;
if (force_nonblock) {
switch (fa->advice) {
case POSIX_FADV_NORMAL:
case POSIX_FADV_RANDOM:
case POSIX_FADV_SEQUENTIAL:
break;
default:
return -EAGAIN;
}
}
ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
return -EINVAL;
if (sqe->ioprio || sqe->buf_index)
return -EINVAL;
if (req->flags & REQ_F_FIXED_FILE)
return -EBADF;
req->statx.dfd = READ_ONCE(sqe->fd);
req->statx.mask = READ_ONCE(sqe->len);
req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
req->statx.flags = READ_ONCE(sqe->statx_flags);
return 0;
}
static int io_statx(struct io_kiocb *req, bool force_nonblock)
{
struct io_statx *ctx = &req->statx;
int ret;
if (force_nonblock) {
/* only need file table for an actual valid fd */
if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
req->flags |= REQ_F_NO_FILE_TABLE;
return -EAGAIN;
}
ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
ctx->buffer);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
/*
* If we queue this for async, it must not be cancellable. That would
* leave the 'file' in an undeterminate state, and here need to modify
* io_wq_work.flags, so initialize io_wq_work firstly.
*/
io_req_init_async(req);
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
sqe->rw_flags || sqe->buf_index)
return -EINVAL;
if (req->flags & REQ_F_FIXED_FILE)
return -EBADF;
req->close.fd = READ_ONCE(sqe->fd);
if ((req->file && req->file->f_op == &io_uring_fops))
return -EBADF;
req->close.put_file = NULL;
return 0;
}
static int io_close(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_close *close = &req->close;
int ret;
/* might be already done during nonblock submission */
if (!close->put_file) {
ret = close_fd_get_file(close->fd, &close->put_file);
if (ret < 0)
return (ret == -ENOENT) ? -EBADF : ret;
}
/* if the file has a flush method, be safe and punt to async */
if (close->put_file->f_op->flush && force_nonblock) {
/* not safe to cancel at this point */
req->work.flags |= IO_WQ_WORK_NO_CANCEL;
/* was never set, but play safe */
req->flags &= ~REQ_F_NOWAIT;
/* avoid grabbing files - we don't need the files */
req->flags |= REQ_F_NO_FILE_TABLE;
return -EAGAIN;
}
/* No ->flush() or already async, safely close from here */
ret = filp_close(close->put_file, req->work.identity->files);
if (ret < 0)
req_set_fail_links(req);
fput(close->put_file);
close->put_file = NULL;
__io_req_complete(req, ret, 0, cs);
return 0;
}
static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_ring_ctx *ctx = req->ctx;
if (!req->file)
return -EBADF;
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
return -EINVAL;
req->sync.off = READ_ONCE(sqe->off);
req->sync.len = READ_ONCE(sqe->len);
req->sync.flags = READ_ONCE(sqe->sync_range_flags);
return 0;
}
static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
{
int ret;
/* sync_file_range always requires a blocking context */
if (force_nonblock)
return -EAGAIN;
ret = sync_file_range(req->file, req->sync.off, req->sync.len,
req->sync.flags);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
#if defined(CONFIG_NET)
static int io_setup_async_msg(struct io_kiocb *req,
struct io_async_msghdr *kmsg)
{
struct io_async_msghdr *async_msg = req->async_data;
if (async_msg)
return -EAGAIN;
if (io_alloc_async_data(req)) {
if (kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
return -ENOMEM;
}
async_msg = req->async_data;
req->flags |= REQ_F_NEED_CLEANUP;
memcpy(async_msg, kmsg, sizeof(*kmsg));
return -EAGAIN;
}
static int io_sendmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
iomsg->iov = iomsg->fast_iov;
iomsg->msg.msg_name = &iomsg->addr;
return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
req->sr_msg.msg_flags, &iomsg->iov);
}
static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_async_msghdr *async_msg = req->async_data;
struct io_sr_msg *sr = &req->sr_msg;
int ret;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags);
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
return 0;
ret = io_sendmsg_copy_hdr(req, async_msg);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
unsigned flags;
int ret;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req->async_data) {
kmsg = req->async_data;
kmsg->msg.msg_name = &kmsg->addr;
/* if iov is set, it's allocated already */
if (!kmsg->iov)
kmsg->iov = kmsg->fast_iov;
kmsg->msg.msg_iter.iov = kmsg->iov;
} else {
ret = io_sendmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
flags = req->sr_msg.msg_flags;
if (flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
else if (force_nonblock)
flags |= MSG_DONTWAIT;
ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
if (force_nonblock && ret == -EAGAIN)
return io_setup_async_msg(req, kmsg);
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, 0, cs);
return 0;
}
static int io_send(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_sr_msg *sr = &req->sr_msg;
struct msghdr msg;
struct iovec iov;
struct socket *sock;
unsigned flags;
int ret;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
if (unlikely(ret))
return ret;
msg.msg_name = NULL;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_namelen = 0;
flags = req->sr_msg.msg_flags;
if (flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
else if (force_nonblock)
flags |= MSG_DONTWAIT;
msg.msg_flags = flags;
ret = sock_sendmsg(sock, &msg);
if (force_nonblock && ret == -EAGAIN)
return -EAGAIN;
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, 0, cs);
return 0;
}
static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct io_sr_msg *sr = &req->sr_msg;
struct iovec __user *uiov;
size_t iov_len;
int ret;
ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
&iomsg->uaddr, &uiov, &iov_len);
if (ret)
return ret;
if (req->flags & REQ_F_BUFFER_SELECT) {
if (iov_len > 1)
return -EINVAL;
if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov)))
return -EFAULT;
sr->len = iomsg->iov[0].iov_len;
iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1,
sr->len);
iomsg->iov = NULL;
} else {
ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
&iomsg->iov, &iomsg->msg.msg_iter,
false);
if (ret > 0)
ret = 0;
}
return ret;
}
#ifdef CONFIG_COMPAT
static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct compat_msghdr __user *msg_compat;
struct io_sr_msg *sr = &req->sr_msg;
struct compat_iovec __user *uiov;
compat_uptr_t ptr;
compat_size_t len;
int ret;
msg_compat = (struct compat_msghdr __user *) sr->umsg;
ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
&ptr, &len);
if (ret)
return ret;
uiov = compat_ptr(ptr);
if (req->flags & REQ_F_BUFFER_SELECT) {
compat_ssize_t clen;
if (len > 1)
return -EINVAL;
if (!access_ok(uiov, sizeof(*uiov)))
return -EFAULT;
if (__get_user(clen, &uiov->iov_len))
return -EFAULT;
if (clen < 0)
return -EINVAL;
sr->len = clen;
iomsg->iov[0].iov_len = clen;
iomsg->iov = NULL;
} else {
ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
UIO_FASTIOV, &iomsg->iov,
&iomsg->msg.msg_iter, true);
if (ret < 0)
return ret;
}
return 0;
}
#endif
static int io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
iomsg->msg.msg_name = &iomsg->addr;
iomsg->iov = iomsg->fast_iov;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
return __io_compat_recvmsg_copy_hdr(req, iomsg);
#endif
return __io_recvmsg_copy_hdr(req, iomsg);
}
static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
bool needs_lock)
{
struct io_sr_msg *sr = &req->sr_msg;
struct io_buffer *kbuf;
kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
if (IS_ERR(kbuf))
return kbuf;
sr->kbuf = kbuf;
req->flags |= REQ_F_BUFFER_SELECTED;
return kbuf;
}
static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
{
return io_put_kbuf(req, req->sr_msg.kbuf);
}
static int io_recvmsg_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_async_msghdr *async_msg = req->async_data;
struct io_sr_msg *sr = &req->sr_msg;
int ret;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags);
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
sr->bgid = READ_ONCE(sqe->buf_group);
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
return 0;
ret = io_recvmsg_copy_hdr(req, async_msg);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
struct io_buffer *kbuf;
unsigned flags;
int ret, cflags = 0;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req->async_data) {
kmsg = req->async_data;
kmsg->msg.msg_name = &kmsg->addr;
/* if iov is set, it's allocated already */
if (!kmsg->iov)
kmsg->iov = kmsg->fast_iov;
kmsg->msg.msg_iter.iov = kmsg->iov;
} else {
ret = io_recvmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
if (req->flags & REQ_F_BUFFER_SELECT) {
kbuf = io_recv_buffer_select(req, !force_nonblock);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
1, req->sr_msg.len);
}
flags = req->sr_msg.msg_flags;
if (flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
else if (force_nonblock)
flags |= MSG_DONTWAIT;
ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
kmsg->uaddr, flags);
if (force_nonblock && ret == -EAGAIN)
return io_setup_async_msg(req, kmsg);
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (req->flags & REQ_F_BUFFER_SELECTED)
cflags = io_put_recv_kbuf(req);
if (kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, cflags, cs);
return 0;
}
static int io_recv(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_buffer *kbuf;
struct io_sr_msg *sr = &req->sr_msg;
struct msghdr msg;
void __user *buf = sr->buf;
struct socket *sock;
struct iovec iov;
unsigned flags;
int ret, cflags = 0;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req->flags & REQ_F_BUFFER_SELECT) {
kbuf = io_recv_buffer_select(req, !force_nonblock);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
buf = u64_to_user_ptr(kbuf->addr);
}
ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
if (unlikely(ret))
goto out_free;
msg.msg_name = NULL;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_namelen = 0;
msg.msg_iocb = NULL;
msg.msg_flags = 0;
flags = req->sr_msg.msg_flags;
if (flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
else if (force_nonblock)
flags |= MSG_DONTWAIT;
ret = sock_recvmsg(sock, &msg, flags);
if (force_nonblock && ret == -EAGAIN)
return -EAGAIN;
if (ret == -ERESTARTSYS)
ret = -EINTR;
out_free:
if (req->flags & REQ_F_BUFFER_SELECTED)
cflags = io_put_recv_kbuf(req);
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, cflags, cs);
return 0;
}
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_accept *accept = &req->accept;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->len || sqe->buf_index)
return -EINVAL;
accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
accept->flags = READ_ONCE(sqe->accept_flags);
accept->nofile = rlimit(RLIMIT_NOFILE);
return 0;
}
static int io_accept(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_accept *accept = &req->accept;
unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
int ret;
if (req->file->f_flags & O_NONBLOCK)
req->flags |= REQ_F_NOWAIT;
ret = __sys_accept4_file(req->file, file_flags, accept->addr,
accept->addr_len, accept->flags,
accept->nofile);
if (ret == -EAGAIN && force_nonblock)
return -EAGAIN;
if (ret < 0) {
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail_links(req);
}
__io_req_complete(req, ret, 0, cs);
return 0;
}
static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_connect *conn = &req->connect;
struct io_async_connect *io = req->async_data;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags)
return -EINVAL;
conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
conn->addr_len = READ_ONCE(sqe->addr2);
if (!io)
return 0;
return move_addr_to_kernel(conn->addr, conn->addr_len,
&io->address);
}
static int io_connect(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_async_connect __io, *io;
unsigned file_flags;
int ret;
if (req->async_data) {
io = req->async_data;
} else {
ret = move_addr_to_kernel(req->connect.addr,
req->connect.addr_len,
&__io.address);
if (ret)
goto out;
io = &__io;
}
file_flags = force_nonblock ? O_NONBLOCK : 0;
ret = __sys_connect_file(req->file, &io->address,
req->connect.addr_len, file_flags);
if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
if (req->async_data)
return -EAGAIN;
if (io_alloc_async_data(req)) {
ret = -ENOMEM;
goto out;
}
io = req->async_data;
memcpy(req->async_data, &__io, sizeof(__io));
return -EAGAIN;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
out:
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, 0, cs);
return 0;
}
#else /* !CONFIG_NET */
static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
return -EOPNOTSUPP;
}
static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
static int io_send(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
static int io_recvmsg_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
return -EOPNOTSUPP;
}
static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
static int io_recv(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
return -EOPNOTSUPP;
}
static int io_accept(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
return -EOPNOTSUPP;
}
static int io_connect(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_NET */
struct io_poll_table {
struct poll_table_struct pt;
struct io_kiocb *req;
int error;
};
static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
__poll_t mask, task_work_func_t func)
{
int ret;
/* for instances that support it check for an event match first: */
if (mask && !(mask & poll->events))
return 0;
trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
list_del_init(&poll->wait.entry);
req->result = mask;
init_task_work(&req->task_work, func);
percpu_ref_get(&req->ctx->refs);
/*
* If this fails, then the task is exiting. When a task exits, the
* work gets canceled, so just cancel this request as well instead
* of executing it. We can't safely execute it anyway, as we may not
* have the needed state needed for it anyway.
*/
ret = io_req_task_work_add(req);
if (unlikely(ret)) {
struct task_struct *tsk;
WRITE_ONCE(poll->canceled, true);
tsk = io_wq_get_task(req->ctx->io_wq);
task_work_add(tsk, &req->task_work, TWA_NONE);
wake_up_process(tsk);
}
return 1;
}
static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
__acquires(&req->ctx->completion_lock)
{
struct io_ring_ctx *ctx = req->ctx;
if (!req->result && !READ_ONCE(poll->canceled)) {
struct poll_table_struct pt = { ._key = poll->events };
req->result = vfs_poll(req->file, &pt) & poll->events;
}
spin_lock_irq(&ctx->completion_lock);
if (!req->result && !READ_ONCE(poll->canceled)) {
add_wait_queue(poll->head, &poll->wait);
return true;
}
return false;
}
static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
{
/* pure poll stashes this in ->async_data, poll driven retry elsewhere */
if (req->opcode == IORING_OP_POLL_ADD)
return req->async_data;
return req->apoll->double_poll;
}
static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
{
if (req->opcode == IORING_OP_POLL_ADD)
return &req->poll;
return &req->apoll->poll;
}
static void io_poll_remove_double(struct io_kiocb *req)
{
struct io_poll_iocb *poll = io_poll_get_double(req);
lockdep_assert_held(&req->ctx->completion_lock);
if (poll && poll->head) {
struct wait_queue_head *head = poll->head;
spin_lock(&head->lock);
list_del_init(&poll->wait.entry);
if (poll->wait.private)
refcount_dec(&req->refs);
poll->head = NULL;
spin_unlock(&head->lock);
}
}
static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
{
struct io_ring_ctx *ctx = req->ctx;
io_poll_remove_double(req);
req->poll.done = true;
io_cqring_fill_event(req, error ? error : mangle_poll(mask));
io_commit_cqring(ctx);
}
static void io_poll_task_func(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *nxt;
if (io_poll_rewait(req, &req->poll)) {
spin_unlock_irq(&ctx->completion_lock);
} else {
hash_del(&req->hash_node);
io_poll_complete(req, req->result, 0);
spin_unlock_irq(&ctx->completion_lock);
nxt = io_put_req_find_next(req);
io_cqring_ev_posted(ctx);
if (nxt)
__io_req_task_submit(nxt);
}
percpu_ref_put(&ctx->refs);
}
static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
int sync, void *key)
{
struct io_kiocb *req = wait->private;
struct io_poll_iocb *poll = io_poll_get_single(req);
__poll_t mask = key_to_poll(key);
/* for instances that support it check for an event match first: */
if (mask && !(mask & poll->events))
return 0;
list_del_init(&wait->entry);
if (poll && poll->head) {
bool done;
spin_lock(&poll->head->lock);
done = list_empty(&poll->wait.entry);
if (!done)
list_del_init(&poll->wait.entry);
/* make sure double remove sees this as being gone */
wait->private = NULL;
spin_unlock(&poll->head->lock);
if (!done) {
/* use wait func handler, so it matches the rq type */
poll->wait.func(&poll->wait, mode, sync, key);
}
}
refcount_dec(&req->refs);
return 1;
}
static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
wait_queue_func_t wake_func)
{
poll->head = NULL;
poll->done = false;
poll->canceled = false;
poll->events = events;
INIT_LIST_HEAD(&poll->wait.entry);
init_waitqueue_func_entry(&poll->wait, wake_func);
}
static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
struct wait_queue_head *head,
struct io_poll_iocb **poll_ptr)
{
struct io_kiocb *req = pt->req;
/*
* If poll->head is already set, it's because the file being polled
* uses multiple waitqueues for poll handling (eg one for read, one
* for write). Setup a separate io_poll_iocb if this happens.
*/
if (unlikely(poll->head)) {
struct io_poll_iocb *poll_one = poll;
/* already have a 2nd entry, fail a third attempt */
if (*poll_ptr) {
pt->error = -EINVAL;
return;
}
poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
if (!poll) {
pt->error = -ENOMEM;
return;
}
io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake);
refcount_inc(&req->refs);
poll->wait.private = req;
*poll_ptr = poll;
}
pt->error = 0;
poll->head = head;
if (poll->events & EPOLLEXCLUSIVE)
add_wait_queue_exclusive(head, &poll->wait);
else
add_wait_queue(head, &poll->wait);
}
static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
struct poll_table_struct *p)
{
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
struct async_poll *apoll = pt->req->apoll;
__io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
}
static void io_async_task_func(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
struct async_poll *apoll = req->apoll;
struct io_ring_ctx *ctx = req->ctx;
trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
if (io_poll_rewait(req, &apoll->poll)) {
spin_unlock_irq(&ctx->completion_lock);
percpu_ref_put(&ctx->refs);
return;
}
/* If req is still hashed, it cannot have been canceled. Don't check. */
if (hash_hashed(&req->hash_node))
hash_del(&req->hash_node);
io_poll_remove_double(req);
spin_unlock_irq(&ctx->completion_lock);
if (!READ_ONCE(apoll->poll.canceled))
__io_req_task_submit(req);
else
__io_req_task_cancel(req, -ECANCELED);
percpu_ref_put(&ctx->refs);
kfree(apoll->double_poll);
kfree(apoll);
}
static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
void *key)
{
struct io_kiocb *req = wait->private;
struct io_poll_iocb *poll = &req->apoll->poll;
trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
key_to_poll(key));
return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
}
static void io_poll_req_insert(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct hlist_head *list;
list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
hlist_add_head(&req->hash_node, list);
}
static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
struct io_poll_iocb *poll,
struct io_poll_table *ipt, __poll_t mask,
wait_queue_func_t wake_func)
__acquires(&ctx->completion_lock)
{
struct io_ring_ctx *ctx = req->ctx;
bool cancel = false;
INIT_HLIST_NODE(&req->hash_node);
io_init_poll_iocb(poll, mask, wake_func);
poll->file = req->file;
poll->wait.private = req;
ipt->pt._key = mask;
ipt->req = req;
ipt->error = -EINVAL;
mask = vfs_poll(req->file, &ipt->pt) & poll->events;
spin_lock_irq(&ctx->completion_lock);
if (likely(poll->head)) {
spin_lock(&poll->head->lock);
if (unlikely(list_empty(&poll->wait.entry))) {
if (ipt->error)
cancel = true;
ipt->error = 0;
mask = 0;
}
if (mask || ipt->error)
list_del_init(&poll->wait.entry);
else if (cancel)
WRITE_ONCE(poll->canceled, true);
else if (!poll->done) /* actually waiting for an event */
io_poll_req_insert(req);
spin_unlock(&poll->head->lock);
}
return mask;
}
static bool io_arm_poll_handler(struct io_kiocb *req)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
struct io_ring_ctx *ctx = req->ctx;
struct async_poll *apoll;
struct io_poll_table ipt;
__poll_t mask, ret;
int rw;
if (!req->file || !file_can_poll(req->file))
return false;
if (req->flags & REQ_F_POLLED)
return false;
if (def->pollin)
rw = READ;
else if (def->pollout)
rw = WRITE;
else
return false;
/* if we can't nonblock try, then no point in arming a poll handler */
if (!io_file_supports_async(req->file, rw))
return false;
apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
if (unlikely(!apoll))
return false;
apoll->double_poll = NULL;
req->flags |= REQ_F_POLLED;
req->apoll = apoll;
mask = 0;
if (def->pollin)
mask |= POLLIN | POLLRDNORM;
if (def->pollout)
mask |= POLLOUT | POLLWRNORM;
/* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
if ((req->opcode == IORING_OP_RECVMSG) &&
(req->sr_msg.msg_flags & MSG_ERRQUEUE))
mask &= ~POLLIN;
mask |= POLLERR | POLLPRI;
ipt.pt._qproc = io_async_queue_proc;
ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
io_async_wake);
if (ret || ipt.error) {
io_poll_remove_double(req);
spin_unlock_irq(&ctx->completion_lock);
kfree(apoll->double_poll);
kfree(apoll);
return false;
}
spin_unlock_irq(&ctx->completion_lock);
trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
apoll->poll.events);
return true;
}
static bool __io_poll_remove_one(struct io_kiocb *req,
struct io_poll_iocb *poll)
{
bool do_complete = false;
spin_lock(&poll->head->lock);
WRITE_ONCE(poll->canceled, true);
if (!list_empty(&poll->wait.entry)) {
list_del_init(&poll->wait.entry);
do_complete = true;
}
spin_unlock(&poll->head->lock);
hash_del(&req->hash_node);
return do_complete;
}
static bool io_poll_remove_one(struct io_kiocb *req)
{
bool do_complete;
io_poll_remove_double(req);
if (req->opcode == IORING_OP_POLL_ADD) {
do_complete = __io_poll_remove_one(req, &req->poll);
} else {
struct async_poll *apoll = req->apoll;
/* non-poll requests have submit ref still */
do_complete = __io_poll_remove_one(req, &apoll->poll);
if (do_complete) {
io_put_req(req);
kfree(apoll->double_poll);
kfree(apoll);
}
}
if (do_complete) {
io_cqring_fill_event(req, -ECANCELED);
io_commit_cqring(req->ctx);
req_set_fail_links(req);
io_put_req_deferred(req, 1);
}
return do_complete;
}
/*
* Returns true if we found and killed one or more poll requests
*/
static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
struct files_struct *files)
{
struct hlist_node *tmp;
struct io_kiocb *req;
int posted = 0, i;
spin_lock_irq(&ctx->completion_lock);
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
struct hlist_head *list;
list = &ctx->cancel_hash[i];
hlist_for_each_entry_safe(req, tmp, list, hash_node) {
if (io_match_task(req, tsk, files))
posted += io_poll_remove_one(req);
}
}
spin_unlock_irq(&ctx->completion_lock);
if (posted)
io_cqring_ev_posted(ctx);
return posted != 0;
}
static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
{
struct hlist_head *list;
struct io_kiocb *req;
list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
hlist_for_each_entry(req, list, hash_node) {
if (sqe_addr != req->user_data)
continue;
if (io_poll_remove_one(req))
return 0;
return -EALREADY;
}
return -ENOENT;
}
static int io_poll_remove_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
sqe->poll_events)
return -EINVAL;
req->poll_remove.addr = READ_ONCE(sqe->addr);
return 0;
}
/*
* Find a running poll command that matches one specified in sqe->addr,
* and remove it if found.
*/
static int io_poll_remove(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
int ret;
spin_lock_irq(&ctx->completion_lock);
ret = io_poll_cancel(ctx, req->poll_remove.addr);
spin_unlock_irq(&ctx->completion_lock);
if (ret < 0)
req_set_fail_links(req);
io_req_complete(req, ret);
return 0;
}
static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
void *key)
{
struct io_kiocb *req = wait->private;
struct io_poll_iocb *poll = &req->poll;
return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
}
static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
struct poll_table_struct *p)
{
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
__io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data);
}
static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_poll_iocb *poll = &req->poll;
u32 events;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
return -EINVAL;
events = READ_ONCE(sqe->poll32_events);
#ifdef __BIG_ENDIAN
events = swahw32(events);
#endif
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP |
(events & EPOLLEXCLUSIVE);
return 0;
}
static int io_poll_add(struct io_kiocb *req)
{
struct io_poll_iocb *poll = &req->poll;
struct io_ring_ctx *ctx = req->ctx;
struct io_poll_table ipt;
__poll_t mask;
ipt.pt._qproc = io_poll_queue_proc;
mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
io_poll_wake);
if (mask) { /* no async, we'd stolen it */
ipt.error = 0;
io_poll_complete(req, mask, 0);
}
spin_unlock_irq(&ctx->completion_lock);
if (mask) {
io_cqring_ev_posted(ctx);
io_put_req(req);
}
return ipt.error;
}
static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
{
struct io_timeout_data *data = container_of(timer,
struct io_timeout_data, timer);
struct io_kiocb *req = data->req;
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags);
list_del_init(&req->timeout.list);
atomic_set(&req->ctx->cq_timeouts,
atomic_read(&req->ctx->cq_timeouts) + 1);
io_cqring_fill_event(req, -ETIME);
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
io_cqring_ev_posted(ctx);
req_set_fail_links(req);
io_put_req(req);
return HRTIMER_NORESTART;
}
static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
__u64 user_data)
{
struct io_timeout_data *io;
struct io_kiocb *req;
int ret = -ENOENT;
list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
if (user_data == req->user_data) {
ret = 0;
break;
}
}
if (ret == -ENOENT)
return ERR_PTR(ret);
io = req->async_data;
ret = hrtimer_try_to_cancel(&io->timer);
if (ret == -1)
return ERR_PTR(-EALREADY);
list_del_init(&req->timeout.list);
return req;
}
static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
{
struct io_kiocb *req = io_timeout_extract(ctx, user_data);
if (IS_ERR(req))
return PTR_ERR(req);
req_set_fail_links(req);
io_cqring_fill_event(req, -ECANCELED);
io_put_req_deferred(req, 1);
return 0;
}
static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
struct timespec64 *ts, enum hrtimer_mode mode)
{
struct io_kiocb *req = io_timeout_extract(ctx, user_data);
struct io_timeout_data *data;
if (IS_ERR(req))
return PTR_ERR(req);
req->timeout.off = 0; /* noseq */
data = req->async_data;
list_add_tail(&req->timeout.list, &ctx->timeout_list);
hrtimer_init(&data->timer, CLOCK_MONOTONIC, mode);
data->timer.function = io_timeout_fn;
hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
return 0;
}
static int io_timeout_remove_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_timeout_rem *tr = &req->timeout_rem;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
return -EINVAL;
if (sqe->ioprio || sqe->buf_index || sqe->len)
return -EINVAL;
tr->addr = READ_ONCE(sqe->addr);
tr->flags = READ_ONCE(sqe->timeout_flags);
if (tr->flags & IORING_TIMEOUT_UPDATE) {
if (tr->flags & ~(IORING_TIMEOUT_UPDATE|IORING_TIMEOUT_ABS))
return -EINVAL;
if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
return -EFAULT;
} else if (tr->flags) {
/* timeout removal doesn't support flags */
return -EINVAL;
}
return 0;
}
/*
* Remove or update an existing timeout command
*/
static int io_timeout_remove(struct io_kiocb *req)
{
struct io_timeout_rem *tr = &req->timeout_rem;
struct io_ring_ctx *ctx = req->ctx;
int ret;
spin_lock_irq(&ctx->completion_lock);
if (req->timeout_rem.flags & IORING_TIMEOUT_UPDATE) {
enum hrtimer_mode mode = (tr->flags & IORING_TIMEOUT_ABS)
? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
} else {
ret = io_timeout_cancel(ctx, tr->addr);
}
io_cqring_fill_event(req, ret);
io_commit_cqring(ctx);
spin_unlock_irq(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
if (ret < 0)
req_set_fail_links(req);
io_put_req(req);
return 0;
}
static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
bool is_timeout_link)
{
struct io_timeout_data *data;
unsigned flags;
u32 off = READ_ONCE(sqe->off);
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (sqe->ioprio || sqe->buf_index || sqe->len != 1)
return -EINVAL;
if (off && is_timeout_link)
return -EINVAL;
flags = READ_ONCE(sqe->timeout_flags);
if (flags & ~IORING_TIMEOUT_ABS)
return -EINVAL;
req->timeout.off = off;
if (!req->async_data && io_alloc_async_data(req))
return -ENOMEM;
data = req->async_data;
data->req = req;
if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
return -EFAULT;
if (flags & IORING_TIMEOUT_ABS)
data->mode = HRTIMER_MODE_ABS;
else
data->mode = HRTIMER_MODE_REL;
hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
return 0;
}
static int io_timeout(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_timeout_data *data = req->async_data;
struct list_head *entry;
u32 tail, off = req->timeout.off;
spin_lock_irq(&ctx->completion_lock);
/*
* sqe->off holds how many events that need to occur for this
* timeout event to be satisfied. If it isn't set, then this is
* a pure timeout request, sequence isn't used.
*/
if (io_is_timeout_noseq(req)) {
entry = ctx->timeout_list.prev;
goto add;
}
tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
req->timeout.target_seq = tail + off;
/* Update the last seq here in case io_flush_timeouts() hasn't.
* This is safe because ->completion_lock is held, and submissions
* and completions are never mixed in the same ->completion_lock section.
*/
ctx->cq_last_tm_flush = tail;
/*
* Insertion sort, ensuring the first entry in the list is always
* the one we need first.
*/
list_for_each_prev(entry, &ctx->timeout_list) {
struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
timeout.list);
if (io_is_timeout_noseq(nxt))
continue;
/* nxt.seq is behind @tail, otherwise would've been completed */
if (off >= nxt->timeout.target_seq - tail)
break;
}
add:
list_add(&req->timeout.list, entry);
data->timer.function = io_timeout_fn;
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
spin_unlock_irq(&ctx->completion_lock);
return 0;
}
static bool io_cancel_cb(struct io_wq_work *work, void *data)
{
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
return req->user_data == (unsigned long) data;
}
static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
{
enum io_wq_cancel cancel_ret;
int ret = 0;
cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false);
switch (cancel_ret) {
case IO_WQ_CANCEL_OK:
ret = 0;
break;
case IO_WQ_CANCEL_RUNNING:
ret = -EALREADY;
break;
case IO_WQ_CANCEL_NOTFOUND:
ret = -ENOENT;
break;
}
return ret;
}
static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
struct io_kiocb *req, __u64 sqe_addr,
int success_ret)
{
unsigned long flags;
int ret;
ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
if (ret != -ENOENT) {
spin_lock_irqsave(&ctx->completion_lock, flags);
goto done;
}
spin_lock_irqsave(&ctx->completion_lock, flags);
ret = io_timeout_cancel(ctx, sqe_addr);
if (ret != -ENOENT)
goto done;
ret = io_poll_cancel(ctx, sqe_addr);
done:
if (!ret)
ret = success_ret;
io_cqring_fill_event(req, ret);
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
io_cqring_ev_posted(ctx);
if (ret < 0)
req_set_fail_links(req);
io_put_req(req);
}
static int io_async_cancel_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
return -EINVAL;
if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags)
return -EINVAL;
req->cancel.addr = READ_ONCE(sqe->addr);
return 0;
}
static int io_async_cancel(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
return 0;
}
static int io_files_update_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL))
return -EINVAL;
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
return -EINVAL;
if (sqe->ioprio || sqe->rw_flags)
return -EINVAL;
req->files_update.offset = READ_ONCE(sqe->off);
req->files_update.nr_args = READ_ONCE(sqe->len);
if (!req->files_update.nr_args)
return -EINVAL;
req->files_update.arg = READ_ONCE(sqe->addr);
return 0;
}
static int io_files_update(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_uring_files_update up;
int ret;
if (force_nonblock)
return -EAGAIN;
up.offset = req->files_update.offset;
up.fds = req->files_update.arg;
mutex_lock(&ctx->uring_lock);
ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
mutex_unlock(&ctx->uring_lock);
if (ret < 0)
req_set_fail_links(req);
__io_req_complete(req, ret, 0, cs);
return 0;
}
static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
switch (req->opcode) {
case IORING_OP_NOP:
return 0;
case IORING_OP_READV:
case IORING_OP_READ_FIXED:
case IORING_OP_READ:
return io_read_prep(req, sqe);
case IORING_OP_WRITEV:
case IORING_OP_WRITE_FIXED:
case IORING_OP_WRITE:
return io_write_prep(req, sqe);
case IORING_OP_POLL_ADD:
return io_poll_add_prep(req, sqe);
case IORING_OP_POLL_REMOVE:
return io_poll_remove_prep(req, sqe);
case IORING_OP_FSYNC:
return io_prep_fsync(req, sqe);
case IORING_OP_SYNC_FILE_RANGE:
return io_prep_sfr(req, sqe);
case IORING_OP_SENDMSG:
case IORING_OP_SEND:
return io_sendmsg_prep(req, sqe);
case IORING_OP_RECVMSG:
case IORING_OP_RECV:
return io_recvmsg_prep(req, sqe);
case IORING_OP_CONNECT:
return io_connect_prep(req, sqe);
case IORING_OP_TIMEOUT:
return io_timeout_prep(req, sqe, false);
case IORING_OP_TIMEOUT_REMOVE:
return io_timeout_remove_prep(req, sqe);
case IORING_OP_ASYNC_CANCEL:
return io_async_cancel_prep(req, sqe);
case IORING_OP_LINK_TIMEOUT:
return io_timeout_prep(req, sqe, true);
case IORING_OP_ACCEPT:
return io_accept_prep(req, sqe);
case IORING_OP_FALLOCATE:
return io_fallocate_prep(req, sqe);
case IORING_OP_OPENAT:
return io_openat_prep(req, sqe);
case IORING_OP_CLOSE:
return io_close_prep(req, sqe);
case IORING_OP_FILES_UPDATE:
return io_files_update_prep(req, sqe);
case IORING_OP_STATX:
return io_statx_prep(req, sqe);
case IORING_OP_FADVISE:
return io_fadvise_prep(req, sqe);
case IORING_OP_MADVISE:
return io_madvise_prep(req, sqe);
case IORING_OP_OPENAT2:
return io_openat2_prep(req, sqe);
case IORING_OP_EPOLL_CTL:
return io_epoll_ctl_prep(req, sqe);
case IORING_OP_SPLICE:
return io_splice_prep(req, sqe);
case IORING_OP_PROVIDE_BUFFERS:
return io_provide_buffers_prep(req, sqe);
case IORING_OP_REMOVE_BUFFERS:
return io_remove_buffers_prep(req, sqe);
case IORING_OP_TEE:
return io_tee_prep(req, sqe);
case IORING_OP_SHUTDOWN:
return io_shutdown_prep(req, sqe);
case IORING_OP_RENAMEAT:
return io_renameat_prep(req, sqe);
case IORING_OP_UNLINKAT:
return io_unlinkat_prep(req, sqe);
}
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
return-EINVAL;
}
static int io_req_defer_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
if (!sqe)
return 0;
if (io_alloc_async_data(req))
return -EAGAIN;
return io_req_prep(req, sqe);
}
static u32 io_get_sequence(struct io_kiocb *req)
{
struct io_kiocb *pos;
struct io_ring_ctx *ctx = req->ctx;
u32 total_submitted, nr_reqs = 0;
io_for_each_link(pos, req)
nr_reqs++;
total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;
return total_submitted - nr_reqs;
}
static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_defer_entry *de;
int ret;
u32 seq;
/* Still need defer if there is pending req in defer list. */
if (likely(list_empty_careful(&ctx->defer_list) &&
!(req->flags & REQ_F_IO_DRAIN)))
return 0;
seq = io_get_sequence(req);
/* Still a chance to pass the sequence check */
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
return 0;
if (!req->async_data) {
ret = io_req_defer_prep(req, sqe);
if (ret)
return ret;
}
io_prep_async_link(req);
de = kmalloc(sizeof(*de), GFP_KERNEL);
if (!de)
return -ENOMEM;
spin_lock_irq(&ctx->completion_lock);
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
spin_unlock_irq(&ctx->completion_lock);
kfree(de);
io_queue_async_work(req);
return -EIOCBQUEUED;
}
trace_io_uring_defer(ctx, req, req->user_data);
de->req = req;
de->seq = seq;
list_add_tail(&de->list, &ctx->defer_list);
spin_unlock_irq(&ctx->completion_lock);
return -EIOCBQUEUED;
}
static void io_req_drop_files(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_uring_task *tctx = req->task->io_uring;
unsigned long flags;
if (req->work.flags & IO_WQ_WORK_FILES) {
put_files_struct(req->work.identity->files);
put_nsproxy(req->work.identity->nsproxy);
}
spin_lock_irqsave(&ctx->inflight_lock, flags);
list_del(&req->inflight_entry);
spin_unlock_irqrestore(&ctx->inflight_lock, flags);
req->flags &= ~REQ_F_INFLIGHT;
req->work.flags &= ~IO_WQ_WORK_FILES;
if (atomic_read(&tctx->in_idle))
wake_up(&tctx->wait);
}
static void __io_clean_op(struct io_kiocb *req)
{
if (req->flags & REQ_F_BUFFER_SELECTED) {
switch (req->opcode) {
case IORING_OP_READV:
case IORING_OP_READ_FIXED:
case IORING_OP_READ:
kfree((void *)(unsigned long)req->rw.addr);
break;
case IORING_OP_RECVMSG:
case IORING_OP_RECV:
kfree(req->sr_msg.kbuf);
break;
}
req->flags &= ~REQ_F_BUFFER_SELECTED;
}
if (req->flags & REQ_F_NEED_CLEANUP) {
switch (req->opcode) {
case IORING_OP_READV:
case IORING_OP_READ_FIXED:
case IORING_OP_READ:
case IORING_OP_WRITEV:
case IORING_OP_WRITE_FIXED:
case IORING_OP_WRITE: {
struct io_async_rw *io = req->async_data;
if (io->free_iovec)
kfree(io->free_iovec);
break;
}
case IORING_OP_RECVMSG:
case IORING_OP_SENDMSG: {
struct io_async_msghdr *io = req->async_data;
if (io->iov != io->fast_iov)
kfree(io->iov);
break;
}
case IORING_OP_SPLICE:
case IORING_OP_TEE:
io_put_file(req, req->splice.file_in,
(req->splice.flags & SPLICE_F_FD_IN_FIXED));
break;
case IORING_OP_OPENAT:
case IORING_OP_OPENAT2:
if (req->open.filename)
putname(req->open.filename);
break;
case IORING_OP_RENAMEAT:
putname(req->rename.oldpath);
putname(req->rename.newpath);
break;
case IORING_OP_UNLINKAT:
putname(req->unlink.filename);
break;
}
req->flags &= ~REQ_F_NEED_CLEANUP;
}
}
static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
struct io_comp_state *cs)
{
struct io_ring_ctx *ctx = req->ctx;
int ret;
switch (req->opcode) {
case IORING_OP_NOP:
ret = io_nop(req, cs);
break;
case IORING_OP_READV:
case IORING_OP_READ_FIXED:
case IORING_OP_READ:
ret = io_read(req, force_nonblock, cs);
break;
case IORING_OP_WRITEV:
case IORING_OP_WRITE_FIXED:
case IORING_OP_WRITE:
ret = io_write(req, force_nonblock, cs);
break;
case IORING_OP_FSYNC:
ret = io_fsync(req, force_nonblock);
break;
case IORING_OP_POLL_ADD:
ret = io_poll_add(req);
break;
case IORING_OP_POLL_REMOVE:
ret = io_poll_remove(req);
break;
case IORING_OP_SYNC_FILE_RANGE:
ret = io_sync_file_range(req, force_nonblock);
break;
case IORING_OP_SENDMSG:
ret = io_sendmsg(req, force_nonblock, cs);
break;
case IORING_OP_SEND:
ret = io_send(req, force_nonblock, cs);
break;
case IORING_OP_RECVMSG:
ret = io_recvmsg(req, force_nonblock, cs);
break;
case IORING_OP_RECV:
ret = io_recv(req, force_nonblock, cs);
break;
case IORING_OP_TIMEOUT:
ret = io_timeout(req);
break;
case IORING_OP_TIMEOUT_REMOVE:
ret = io_timeout_remove(req);
break;
case IORING_OP_ACCEPT:
ret = io_accept(req, force_nonblock, cs);
break;
case IORING_OP_CONNECT:
ret = io_connect(req, force_nonblock, cs);
break;
case IORING_OP_ASYNC_CANCEL:
ret = io_async_cancel(req);
break;
case IORING_OP_FALLOCATE:
ret = io_fallocate(req, force_nonblock);
break;
case IORING_OP_OPENAT:
ret = io_openat(req, force_nonblock);
break;
case IORING_OP_CLOSE:
ret = io_close(req, force_nonblock, cs);
break;
case IORING_OP_FILES_UPDATE:
ret = io_files_update(req, force_nonblock, cs);
break;
case IORING_OP_STATX:
ret = io_statx(req, force_nonblock);
break;
case IORING_OP_FADVISE:
ret = io_fadvise(req, force_nonblock);
break;
case IORING_OP_MADVISE:
ret = io_madvise(req, force_nonblock);
break;
case IORING_OP_OPENAT2:
ret = io_openat2(req, force_nonblock);
break;
case IORING_OP_EPOLL_CTL:
ret = io_epoll_ctl(req, force_nonblock, cs);
break;
case IORING_OP_SPLICE:
ret = io_splice(req, force_nonblock);
break;
case IORING_OP_PROVIDE_BUFFERS:
ret = io_provide_buffers(req, force_nonblock, cs);
break;
case IORING_OP_REMOVE_BUFFERS:
ret = io_remove_buffers(req, force_nonblock, cs);
break;
case IORING_OP_TEE:
ret = io_tee(req, force_nonblock);
break;
case IORING_OP_SHUTDOWN:
ret = io_shutdown(req, force_nonblock);
break;
case IORING_OP_RENAMEAT:
ret = io_renameat(req, force_nonblock);
break;
case IORING_OP_UNLINKAT:
ret = io_unlinkat(req, force_nonblock);
break;
default:
ret = -EINVAL;
break;
}
if (ret)
return ret;
/* If the op doesn't have a file, we're not polling for it */
if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
const bool in_async = io_wq_current_is_worker();
/* workqueue context doesn't hold uring_lock, grab it now */
if (in_async)
mutex_lock(&ctx->uring_lock);
io_iopoll_req_issued(req, in_async);
if (in_async)
mutex_unlock(&ctx->uring_lock);
}
return 0;
}
static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
{
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
struct io_kiocb *timeout;
int ret = 0;
timeout = io_prep_linked_timeout(req);
if (timeout)
io_queue_linked_timeout(timeout);
/* if NO_CANCEL is set, we must still run the work */
if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
IO_WQ_WORK_CANCEL) {
ret = -ECANCELED;
}
if (!ret) {
do {
ret = io_issue_sqe(req, false, NULL);
/*
* We can get EAGAIN for polled IO even though we're
* forcing a sync submission from here, since we can't
* wait for request slots on the block side.
*/
if (ret != -EAGAIN)
break;
cond_resched();
} while (1);
}
if (ret) {
struct io_ring_ctx *lock_ctx = NULL;
if (req->ctx->flags & IORING_SETUP_IOPOLL)
lock_ctx = req->ctx;
/*
* io_iopoll_complete() does not hold completion_lock to
* complete polled io, so here for polled io, we can not call
* io_req_complete() directly, otherwise there maybe concurrent
* access to cqring, defer_list, etc, which is not safe. Given
* that io_iopoll_complete() is always called under uring_lock,
* so here for polled io, we also get uring_lock to complete
* it.
*/
if (lock_ctx)
mutex_lock(&lock_ctx->uring_lock);
req_set_fail_links(req);
io_req_complete(req, ret);
if (lock_ctx)
mutex_unlock(&lock_ctx->uring_lock);
}
return io_steal_work(req);
}
static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
int index)
{
struct fixed_file_table *table;
table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
return table->files[index & IORING_FILE_TABLE_MASK];
}
static struct file *io_file_get(struct io_submit_state *state,
struct io_kiocb *req, int fd, bool fixed)
{
struct io_ring_ctx *ctx = req->ctx;
struct file *file;
if (fixed) {
if (unlikely((unsigned int)fd >= ctx->nr_user_files))
return NULL;
fd = array_index_nospec(fd, ctx->nr_user_files);
file = io_file_from_index(ctx, fd);
io_set_resource_node(req);
} else {
trace_io_uring_file_get(ctx, fd);
file = __io_file_get(state, fd);
}
if (file && file->f_op == &io_uring_fops) {
io_req_init_async(req);
req->flags |= REQ_F_INFLIGHT;
spin_lock_irq(&ctx->inflight_lock);
list_add(&req->inflight_entry, &ctx->inflight_list);
spin_unlock_irq(&ctx->inflight_lock);
}
return file;
}
static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
{
struct io_timeout_data *data = container_of(timer,
struct io_timeout_data, timer);
struct io_kiocb *prev, *req = data->req;
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags);
prev = req->timeout.head;
req->timeout.head = NULL;
/*
* We don't expect the list to be empty, that will only happen if we
* race with the completion of the linked work.
*/
if (prev && refcount_inc_not_zero(&prev->refs))
io_remove_next_linked(prev);
else
prev = NULL;
spin_unlock_irqrestore(&ctx->completion_lock, flags);
if (prev) {
req_set_fail_links(prev);
io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
io_put_req(prev);
} else {
io_req_complete(req, -ETIME);
}
return HRTIMER_NORESTART;
}
static void __io_queue_linked_timeout(struct io_kiocb *req)
{
/*
* If the back reference is NULL, then our linked request finished
* before we got a chance to setup the timer
*/
if (req->timeout.head) {
struct io_timeout_data *data = req->async_data;
data->timer.function = io_link_timeout_fn;
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
data->mode);
}
}
static void io_queue_linked_timeout(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
spin_lock_irq(&ctx->completion_lock);
__io_queue_linked_timeout(req);
spin_unlock_irq(&ctx->completion_lock);
/* drop submission reference */
io_put_req(req);
}
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
{
struct io_kiocb *nxt = req->link;
if (!nxt || (req->flags & REQ_F_LINK_TIMEOUT) ||
nxt->opcode != IORING_OP_LINK_TIMEOUT)
return NULL;
nxt->timeout.head = req;
nxt->flags |= REQ_F_LTIMEOUT_ACTIVE;
req->flags |= REQ_F_LINK_TIMEOUT;
return nxt;
}
static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
{
struct io_kiocb *linked_timeout;
const struct cred *old_creds = NULL;
int ret;
again:
linked_timeout = io_prep_linked_timeout(req);
if ((req->flags & REQ_F_WORK_INITIALIZED) &&
(req->work.flags & IO_WQ_WORK_CREDS) &&
req->work.identity->creds != current_cred()) {
if (old_creds)
revert_creds(old_creds);
if (old_creds == req->work.identity->creds)
old_creds = NULL; /* restored original creds */
else
old_creds = override_creds(req->work.identity->creds);
}
ret = io_issue_sqe(req, true, cs);
/*
* We async punt it if the file wasn't marked NOWAIT, or if the file
* doesn't support non-blocking read/write attempts
*/
if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
if (!io_arm_poll_handler(req)) {
/*
* Queued up for async execution, worker will release
* submit reference when the iocb is actually submitted.
*/
io_queue_async_work(req);
}
if (linked_timeout)
io_queue_linked_timeout(linked_timeout);
} else if (likely(!ret)) {
/* drop submission reference */
req = io_put_req_find_next(req);
if (linked_timeout)
io_queue_linked_timeout(linked_timeout);
if (req) {
if (!(req->flags & REQ_F_FORCE_ASYNC))
goto again;
io_queue_async_work(req);
}
} else {
/* un-prep timeout, so it'll be killed as any other linked */
req->flags &= ~REQ_F_LINK_TIMEOUT;
req_set_fail_links(req);
io_put_req(req);
io_req_complete(req, ret);
}
if (old_creds)
revert_creds(old_creds);
}
static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
struct io_comp_state *cs)
{
int ret;
ret = io_req_defer(req, sqe);
if (ret) {
if (ret != -EIOCBQUEUED) {
fail_req:
req_set_fail_links(req);
io_put_req(req);
io_req_complete(req, ret);
}
} else if (req->flags & REQ_F_FORCE_ASYNC) {
if (!req->async_data) {
ret = io_req_defer_prep(req, sqe);
if (unlikely(ret))
goto fail_req;
}
io_queue_async_work(req);
} else {
if (sqe) {
ret = io_req_prep(req, sqe);
if (unlikely(ret))
goto fail_req;
}
__io_queue_sqe(req, cs);
}
}
static inline void io_queue_link_head(struct io_kiocb *req,
struct io_comp_state *cs)
{
if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
io_put_req(req);
io_req_complete(req, -ECANCELED);
} else
io_queue_sqe(req, NULL, cs);
}
struct io_submit_link {
struct io_kiocb *head;
struct io_kiocb *last;
};
static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
struct io_submit_link *link, struct io_comp_state *cs)
{
struct io_ring_ctx *ctx = req->ctx;
int ret;
/*
* If we already have a head request, queue this one for async
* submittal once the head completes. If we don't have a head but
* IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
* submitted sync once the chain is complete. If none of those
* conditions are true (normal request), then just queue it.
*/
if (link->head) {
struct io_kiocb *head = link->head;
/*
* Taking sequential execution of a link, draining both sides
* of the link also fullfils IOSQE_IO_DRAIN semantics for all
* requests in the link. So, it drains the head and the
* next after the link request. The last one is done via
* drain_next flag to persist the effect across calls.
*/
if (req->flags & REQ_F_IO_DRAIN) {
head->flags |= REQ_F_IO_DRAIN;
ctx->drain_next = 1;
}
ret = io_req_defer_prep(req, sqe);
if (unlikely(ret)) {
/* fail even hard links since we don't submit */
head->flags |= REQ_F_FAIL_LINK;
return ret;
}
trace_io_uring_link(ctx, req, head);
link->last->link = req;
link->last = req;
/* last request of a link, enqueue the link */
if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
io_queue_link_head(head, cs);
link->head = NULL;
}
} else {
if (unlikely(ctx->drain_next)) {
req->flags |= REQ_F_IO_DRAIN;
ctx->drain_next = 0;
}
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
ret = io_req_defer_prep(req, sqe);
if (unlikely(ret))
req->flags |= REQ_F_FAIL_LINK;
link->head = req;
link->last = req;
} else {
io_queue_sqe(req, sqe, cs);
}
}
return 0;
}
/*
* Batched submission is done, ensure local IO is flushed out.
*/
static void io_submit_state_end(struct io_submit_state *state)
{
if (!list_empty(&state->comp.list))
io_submit_flush_completions(&state->comp);
if (state->plug_started)
blk_finish_plug(&state->plug);
io_state_file_put(state);
if (state->free_reqs)
kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
}
/*
* Start submission side cache.
*/
static void io_submit_state_start(struct io_submit_state *state,
struct io_ring_ctx *ctx, unsigned int max_ios)
{
state->plug_started = false;
state->comp.nr = 0;
INIT_LIST_HEAD(&state->comp.list);
state->comp.ctx = ctx;
state->free_reqs = 0;
state->file_refs = 0;
state->ios_left = max_ios;
}
static void io_commit_sqring(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
/*
* Ensure any loads from the SQEs are done at this point,
* since once we write the new head, the application could
* write new data to them.
*/
smp_store_release(&rings->sq.head, ctx->cached_sq_head);
}
/*
* Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
* that is mapped by userspace. This means that care needs to be taken to
* ensure that reads are stable, as we cannot rely on userspace always
* being a good citizen. If members of the sqe are validated and then later
* used, it's important that those reads are done through READ_ONCE() to
* prevent a re-load down the line.
*/
static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
{
u32 *sq_array = ctx->sq_array;
unsigned head;
/*
* The cached sq head (or cq tail) serves two purposes:
*
* 1) allows us to batch the cost of updating the user visible
* head updates.
* 2) allows the kernel side to track the head on its own, even
* though the application is the one updating it.
*/
head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
if (likely(head < ctx->sq_entries))
return &ctx->sq_sqes[head];
/* drop invalid entries */
ctx->cached_sq_dropped++;
WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
return NULL;
}
static inline void io_consume_sqe(struct io_ring_ctx *ctx)
{
ctx->cached_sq_head++;
}
/*
* Check SQE restrictions (opcode and flags).
*
* Returns 'true' if SQE is allowed, 'false' otherwise.
*/
static inline bool io_check_restriction(struct io_ring_ctx *ctx,
struct io_kiocb *req,
unsigned int sqe_flags)
{
if (!ctx->restricted)
return true;
if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
return false;
if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
ctx->restrictions.sqe_flags_required)
return false;
if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
ctx->restrictions.sqe_flags_required))
return false;
return true;
}
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
IOSQE_BUFFER_SELECT)
static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
const struct io_uring_sqe *sqe,
struct io_submit_state *state)
{
unsigned int sqe_flags;
int id, ret;
req->opcode = READ_ONCE(sqe->opcode);
req->user_data = READ_ONCE(sqe->user_data);
req->async_data = NULL;
req->file = NULL;
req->ctx = ctx;
req->flags = 0;
req->link = NULL;
req->fixed_file_refs = NULL;
/* one is dropped after submission, the other at completion */
refcount_set(&req->refs, 2);
req->task = current;
req->result = 0;
if (unlikely(req->opcode >= IORING_OP_LAST))
return -EINVAL;
if (unlikely(io_sq_thread_acquire_mm_files(ctx, req)))
return -EFAULT;
sqe_flags = READ_ONCE(sqe->flags);
/* enforce forwards compatibility on users */
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
return -EINVAL;
if (unlikely(!io_check_restriction(ctx, req, sqe_flags)))
return -EACCES;
if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
!io_op_defs[req->opcode].buffer_select)
return -EOPNOTSUPP;
id = READ_ONCE(sqe->personality);
if (id) {
struct io_identity *iod;
iod = idr_find(&ctx->personality_idr, id);
if (unlikely(!iod))
return -EINVAL;
refcount_inc(&iod->count);
__io_req_init_async(req);
get_cred(iod->creds);
req->work.identity = iod;
req->work.flags |= IO_WQ_WORK_CREDS;
}
/* same numerical values with corresponding REQ_F_*, safe to copy */
req->flags |= sqe_flags;
/*
* Plug now if we have more than 1 IO left after this, and the target
* is potentially a read/write to block based storage.
*/
if (!state->plug_started && state->ios_left > 1 &&
io_op_defs[req->opcode].plug) {
blk_start_plug(&state->plug);
state->plug_started = true;
}
ret = 0;
if (io_op_defs[req->opcode].needs_file) {
bool fixed = req->flags & REQ_F_FIXED_FILE;
req->file = io_file_get(state, req, READ_ONCE(sqe->fd), fixed);
if (unlikely(!req->file &&
!io_op_defs[req->opcode].needs_file_no_error))
ret = -EBADF;
}
state->ios_left--;
return ret;
}
static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
{
struct io_submit_state state;
struct io_submit_link link;
int i, submitted = 0;
/* if we have a backlog and couldn't flush it all, return BUSY */
if (test_bit(0, &ctx->sq_check_overflow)) {
if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL))
return -EBUSY;
}
/* make sure SQ entry isn't read before tail */
nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
if (!percpu_ref_tryget_many(&ctx->refs, nr))
return -EAGAIN;
percpu_counter_add(&current->io_uring->inflight, nr);
refcount_add(nr, &current->usage);
io_submit_state_start(&state, ctx, nr);
link.head = NULL;
for (i = 0; i < nr; i++) {
const struct io_uring_sqe *sqe;
struct io_kiocb *req;
int err;
sqe = io_get_sqe(ctx);
if (unlikely(!sqe)) {
io_consume_sqe(ctx);
break;
}
req = io_alloc_req(ctx, &state);
if (unlikely(!req)) {
if (!submitted)
submitted = -EAGAIN;
break;
}
io_consume_sqe(ctx);
/* will complete beyond this point, count as submitted */
submitted++;
err = io_init_req(ctx, req, sqe, &state);
if (unlikely(err)) {
fail_req:
io_put_req(req);
io_req_complete(req, err);
break;
}
trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
true, io_async_submit(ctx));
err = io_submit_sqe(req, sqe, &link, &state.comp);
if (err)
goto fail_req;
}
if (unlikely(submitted != nr)) {
int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
struct io_uring_task *tctx = current->io_uring;
int unused = nr - ref_used;
percpu_ref_put_many(&ctx->refs, unused);
percpu_counter_sub(&tctx->inflight, unused);
put_task_struct_many(current, unused);
}
if (link.head)
io_queue_link_head(link.head, &state.comp);
io_submit_state_end(&state);
/* Commit SQ ring head once we've consumed and submitted all SQEs */
io_commit_sqring(ctx);
return submitted;
}
static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
{
/* Tell userspace we may need a wakeup call */
spin_lock_irq(&ctx->completion_lock);
ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
spin_unlock_irq(&ctx->completion_lock);
}
static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
{
spin_lock_irq(&ctx->completion_lock);
ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
spin_unlock_irq(&ctx->completion_lock);
}
static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
{
unsigned int to_submit;
int ret = 0;
to_submit = io_sqring_entries(ctx);
/* if we're handling multiple rings, cap submit size for fairness */
if (cap_entries && to_submit > 8)
to_submit = 8;
if (!list_empty(&ctx->iopoll_list) || to_submit) {
unsigned nr_events = 0;
mutex_lock(&ctx->uring_lock);
if (!list_empty(&ctx->iopoll_list))
io_do_iopoll(ctx, &nr_events, 0);
if (to_submit && !ctx->sqo_dead &&
likely(!percpu_ref_is_dying(&ctx->refs)))
ret = io_submit_sqes(ctx, to_submit);
mutex_unlock(&ctx->uring_lock);
}
if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait))
wake_up(&ctx->sqo_sq_wait);
return ret;
}
static void io_sqd_update_thread_idle(struct io_sq_data *sqd)
{
struct io_ring_ctx *ctx;
unsigned sq_thread_idle = 0;
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
if (sq_thread_idle < ctx->sq_thread_idle)
sq_thread_idle = ctx->sq_thread_idle;
}
sqd->sq_thread_idle = sq_thread_idle;
}
static void io_sqd_init_new(struct io_sq_data *sqd)
{
struct io_ring_ctx *ctx;
while (!list_empty(&sqd->ctx_new_list)) {
ctx = list_first_entry(&sqd->ctx_new_list, struct io_ring_ctx, sqd_list);
list_move_tail(&ctx->sqd_list, &sqd->ctx_list);
complete(&ctx->sq_thread_comp);
}
io_sqd_update_thread_idle(sqd);
}
static int io_sq_thread(void *data)
{
struct cgroup_subsys_state *cur_css = NULL;
struct files_struct *old_files = current->files;
struct nsproxy *old_nsproxy = current->nsproxy;
const struct cred *old_cred = NULL;
struct io_sq_data *sqd = data;
struct io_ring_ctx *ctx;
unsigned long timeout = 0;
DEFINE_WAIT(wait);
task_lock(current);
current->files = NULL;
current->nsproxy = NULL;
task_unlock(current);
while (!kthread_should_stop()) {
int ret;
bool cap_entries, sqt_spin, needs_sched;
/*
* Any changes to the sqd lists are synchronized through the
* kthread parking. This synchronizes the thread vs users,
* the users are synchronized on the sqd->ctx_lock.
*/
if (kthread_should_park()) {
kthread_parkme();
/*
* When sq thread is unparked, in case the previous park operation
* comes from io_put_sq_data(), which means that sq thread is going
* to be stopped, so here needs to have a check.
*/
if (kthread_should_stop())
break;
}
if (unlikely(!list_empty(&sqd->ctx_new_list))) {
io_sqd_init_new(sqd);
timeout = jiffies + sqd->sq_thread_idle;
}
sqt_spin = false;
cap_entries = !list_is_singular(&sqd->ctx_list);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
if (current->cred != ctx->creds) {
if (old_cred)
revert_creds(old_cred);
old_cred = override_creds(ctx->creds);
}
io_sq_thread_associate_blkcg(ctx, &cur_css);
#ifdef CONFIG_AUDIT
current->loginuid = ctx->loginuid;
current->sessionid = ctx->sessionid;
#endif
ret = __io_sq_thread(ctx, cap_entries);
if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list)))
sqt_spin = true;
io_sq_thread_drop_mm_files();
}
if (sqt_spin || !time_after(jiffies, timeout)) {
io_run_task_work();
io_sq_thread_drop_mm_files();
cond_resched();
if (sqt_spin)
timeout = jiffies + sqd->sq_thread_idle;
continue;
}
if (kthread_should_park())
continue;
needs_sched = true;
prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
if ((ctx->flags & IORING_SETUP_IOPOLL) &&
!list_empty_careful(&ctx->iopoll_list)) {
needs_sched = false;
break;
}
if (io_sqring_entries(ctx)) {
needs_sched = false;
break;
}
}
if (needs_sched) {
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
io_ring_set_wakeup_flag(ctx);
schedule();
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
io_ring_clear_wakeup_flag(ctx);
}
finish_wait(&sqd->wait, &wait);
timeout = jiffies + sqd->sq_thread_idle;
}
io_run_task_work();
io_sq_thread_drop_mm_files();
if (cur_css)
io_sq_thread_unassociate_blkcg();
if (old_cred)
revert_creds(old_cred);
task_lock(current);
current->files = old_files;
current->nsproxy = old_nsproxy;
task_unlock(current);
kthread_parkme();
return 0;
}
struct io_wait_queue {
struct wait_queue_entry wq;
struct io_ring_ctx *ctx;
unsigned to_wait;
unsigned nr_timeouts;
};
static inline bool io_should_wake(struct io_wait_queue *iowq)
{
struct io_ring_ctx *ctx = iowq->ctx;
/*
* Wake up if we have enough events, or if a timeout occurred since we
* started waiting. For timeouts, we always want to return to userspace,
* regardless of event count.
*/
return io_cqring_events(ctx) >= iowq->to_wait ||
atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
}
static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
int wake_flags, void *key)
{
struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
wq);
/*
* Cannot safely flush overflowed CQEs from here, ensure we wake up
* the task, and the next invocation will do it.
*/
if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow))
return autoremove_wake_function(curr, mode, wake_flags, key);
return -1;
}
static int io_run_task_work_sig(void)
{
if (io_run_task_work())
return 1;
if (!signal_pending(current))
return 0;
if (test_tsk_thread_flag(current, TIF_NOTIFY_SIGNAL))
return -ERESTARTSYS;
return -EINTR;
}
/*
* Wait until events become available, if we don't already have some. The
* application must reap them itself, as they reside on the shared cq ring.
*/
static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
const sigset_t __user *sig, size_t sigsz,
struct __kernel_timespec __user *uts)
{
struct io_wait_queue iowq = {
.wq = {
.private = current,
.func = io_wake_function,
.entry = LIST_HEAD_INIT(iowq.wq.entry),
},
.ctx = ctx,
.to_wait = min_events,
};
struct io_rings *rings = ctx->rings;
struct timespec64 ts;
signed long timeout = 0;
int ret = 0;
do {
io_cqring_overflow_flush(ctx, false, NULL, NULL);
if (io_cqring_events(ctx) >= min_events)
return 0;
if (!io_run_task_work())
break;
} while (1);
if (sig) {
#ifdef CONFIG_COMPAT
if (in_compat_syscall())
ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
sigsz);
else
#endif
ret = set_user_sigmask(sig, sigsz);
if (ret)
return ret;
}
if (uts) {
if (get_timespec64(&ts, uts))
return -EFAULT;
timeout = timespec64_to_jiffies(&ts);
}
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
trace_io_uring_cqring_wait(ctx, min_events);
do {
io_cqring_overflow_flush(ctx, false, NULL, NULL);
prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
TASK_INTERRUPTIBLE);
/* make sure we run task_work before checking for signals */
ret = io_run_task_work_sig();
if (ret > 0)
continue;
else if (ret < 0)
break;
if (io_should_wake(&iowq))
break;
if (test_bit(0, &ctx->cq_check_overflow))
continue;
if (uts) {
timeout = schedule_timeout(timeout);
if (timeout == 0) {
ret = -ETIME;
break;
}
} else {
schedule();
}
} while (1);
finish_wait(&ctx->wait, &iowq.wq);
restore_saved_sigmask_unless(ret == -EINTR);
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
}
static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
#if defined(CONFIG_UNIX)
if (ctx->ring_sock) {
struct sock *sock = ctx->ring_sock->sk;
struct sk_buff *skb;
while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
kfree_skb(skb);
}
#else
int i;
for (i = 0; i < ctx->nr_user_files; i++) {
struct file *file;
file = io_file_from_index(ctx, i);
if (file)
fput(file);
}
#endif
}
static void io_file_ref_kill(struct percpu_ref *ref)
{
struct fixed_file_data *data;
data = container_of(ref, struct fixed_file_data, refs);
complete(&data->done);
}
static void io_sqe_files_set_node(struct fixed_file_data *file_data,
struct fixed_file_ref_node *ref_node)
{
spin_lock_bh(&file_data->lock);
file_data->node = ref_node;
list_add_tail(&ref_node->node, &file_data->ref_list);
spin_unlock_bh(&file_data->lock);
percpu_ref_get(&file_data->refs);
}
static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
struct fixed_file_data *data = ctx->file_data;
struct fixed_file_ref_node *backup_node, *ref_node = NULL;
unsigned nr_tables, i;
int ret;
if (!data)
return -ENXIO;
backup_node = alloc_fixed_file_ref_node(ctx);
if (!backup_node)
return -ENOMEM;
spin_lock_bh(&data->lock);
ref_node = data->node;
spin_unlock_bh(&data->lock);
if (ref_node)
percpu_ref_kill(&ref_node->refs);
percpu_ref_kill(&data->refs);
/* wait for all refs nodes to complete */
flush_delayed_work(&ctx->file_put_work);
do {
ret = wait_for_completion_interruptible(&data->done);
if (!ret)
break;
ret = io_run_task_work_sig();
if (ret < 0) {
percpu_ref_resurrect(&data->refs);
reinit_completion(&data->done);
io_sqe_files_set_node(data, backup_node);
return ret;
}
} while (1);
__io_sqe_files_unregister(ctx);
nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
for (i = 0; i < nr_tables; i++)
kfree(data->table[i].files);
kfree(data->table);
percpu_ref_exit(&data->refs);
kfree(data);
ctx->file_data = NULL;
ctx->nr_user_files = 0;
destroy_fixed_file_ref_node(backup_node);
return 0;
}
static void io_put_sq_data(struct io_sq_data *sqd)
{
if (refcount_dec_and_test(&sqd->refs)) {
/*
* The park is a bit of a work-around, without it we get
* warning spews on shutdown with SQPOLL set and affinity
* set to a single CPU.
*/
if (sqd->thread) {
kthread_park(sqd->thread);
kthread_stop(sqd->thread);
}
kfree(sqd);
}
}
static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
{
struct io_ring_ctx *ctx_attach;
struct io_sq_data *sqd;
struct fd f;
f = fdget(p->wq_fd);
if (!f.file)
return ERR_PTR(-ENXIO);
if (f.file->f_op != &io_uring_fops) {
fdput(f);
return ERR_PTR(-EINVAL);
}
ctx_attach = f.file->private_data;
sqd = ctx_attach->sq_data;
if (!sqd) {
fdput(f);
return ERR_PTR(-EINVAL);
}
refcount_inc(&sqd->refs);
fdput(f);
return sqd;
}
static struct io_sq_data *io_get_sq_data(struct io_uring_params *p)
{
struct io_sq_data *sqd;
if (p->flags & IORING_SETUP_ATTACH_WQ)
return io_attach_sq_data(p);
sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
if (!sqd)
return ERR_PTR(-ENOMEM);
refcount_set(&sqd->refs, 1);
INIT_LIST_HEAD(&sqd->ctx_list);
INIT_LIST_HEAD(&sqd->ctx_new_list);
mutex_init(&sqd->ctx_lock);
mutex_init(&sqd->lock);
init_waitqueue_head(&sqd->wait);
return sqd;
}
static void io_sq_thread_unpark(struct io_sq_data *sqd)
__releases(&sqd->lock)
{
if (!sqd->thread)
return;
kthread_unpark(sqd->thread);
mutex_unlock(&sqd->lock);
}
static void io_sq_thread_park(struct io_sq_data *sqd)
__acquires(&sqd->lock)
{
if (!sqd->thread)
return;
mutex_lock(&sqd->lock);
kthread_park(sqd->thread);
}
static void io_sq_thread_stop(struct io_ring_ctx *ctx)
{
struct io_sq_data *sqd = ctx->sq_data;
if (sqd) {
if (sqd->thread) {
/*
* We may arrive here from the error branch in
* io_sq_offload_create() where the kthread is created
* without being waked up, thus wake it up now to make
* sure the wait will complete.
*/
wake_up_process(sqd->thread);
wait_for_completion(&ctx->sq_thread_comp);
io_sq_thread_park(sqd);
}
mutex_lock(&sqd->ctx_lock);
list_del(&ctx->sqd_list);
io_sqd_update_thread_idle(sqd);
mutex_unlock(&sqd->ctx_lock);
if (sqd->thread)
io_sq_thread_unpark(sqd);
io_put_sq_data(sqd);
ctx->sq_data = NULL;
}
}
static void io_finish_async(struct io_ring_ctx *ctx)
{
io_sq_thread_stop(ctx);
if (ctx->io_wq) {
io_wq_destroy(ctx->io_wq);
ctx->io_wq = NULL;
}
}
#if defined(CONFIG_UNIX)
/*
* Ensure the UNIX gc is aware of our file set, so we are certain that
* the io_uring can be safely unregistered on process exit, even if we have
* loops in the file referencing.
*/
static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
{
struct sock *sk = ctx->ring_sock->sk;
struct scm_fp_list *fpl;
struct sk_buff *skb;
int i, nr_files;
fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
if (!fpl)
return -ENOMEM;
skb = alloc_skb(0, GFP_KERNEL);
if (!skb) {
kfree(fpl);
return -ENOMEM;
}
skb->sk = sk;
nr_files = 0;
fpl->user = get_uid(ctx->user);
for (i = 0; i < nr; i++) {
struct file *file = io_file_from_index(ctx, i + offset);
if (!file)
continue;
fpl->fp[nr_files] = get_file(file);
unix_inflight(fpl->user, fpl->fp[nr_files]);
nr_files++;
}
if (nr_files) {
fpl->max = SCM_MAX_FD;
fpl->count = nr_files;
UNIXCB(skb).fp = fpl;
skb->destructor = unix_destruct_scm;
refcount_add(skb->truesize, &sk->sk_wmem_alloc);
skb_queue_head(&sk->sk_receive_queue, skb);
for (i = 0; i < nr_files; i++)
fput(fpl->fp[i]);
} else {
kfree_skb(skb);
kfree(fpl);
}
return 0;
}
/*
* If UNIX sockets are enabled, fd passing can cause a reference cycle which
* causes regular reference counting to break down. We rely on the UNIX
* garbage collection to take care of this problem for us.
*/
static int io_sqe_files_scm(struct io_ring_ctx *ctx)
{
unsigned left, total;
int ret = 0;
total = 0;
left = ctx->nr_user_files;
while (left) {
unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
ret = __io_sqe_files_scm(ctx, this_files, total);
if (ret)
break;
left -= this_files;
total += this_files;
}
if (!ret)
return 0;
while (total < ctx->nr_user_files) {
struct file *file = io_file_from_index(ctx, total);
if (file)
fput(file);
total++;
}
return ret;
}
#else
static int io_sqe_files_scm(struct io_ring_ctx *ctx)
{
return 0;
}
#endif
static int io_sqe_alloc_file_tables(struct fixed_file_data *file_data,
unsigned nr_tables, unsigned nr_files)
{
int i;
for (i = 0; i < nr_tables; i++) {
struct fixed_file_table *table = &file_data->table[i];
unsigned this_files;
this_files = min(nr_files, IORING_MAX_FILES_TABLE);
table->files = kcalloc(this_files, sizeof(struct file *),
GFP_KERNEL);
if (!table->files)
break;
nr_files -= this_files;
}
if (i == nr_tables)
return 0;
for (i = 0; i < nr_tables; i++) {
struct fixed_file_table *table = &file_data->table[i];
kfree(table->files);
}
return 1;
}
static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
{
#if defined(CONFIG_UNIX)
struct sock *sock = ctx->ring_sock->sk;
struct sk_buff_head list, *head = &sock->sk_receive_queue;
struct sk_buff *skb;
int i;
__skb_queue_head_init(&list);
/*
* Find the skb that holds this file in its SCM_RIGHTS. When found,
* remove this entry and rearrange the file array.
*/
skb = skb_dequeue(head);
while (skb) {
struct scm_fp_list *fp;
fp = UNIXCB(skb).fp;
for (i = 0; i < fp->count; i++) {
int left;
if (fp->fp[i] != file)
continue;
unix_notinflight(fp->user, fp->fp[i]);
left = fp->count - 1 - i;
if (left) {
memmove(&fp->fp[i], &fp->fp[i + 1],
left * sizeof(struct file *));
}
fp->count--;
if (!fp->count) {
kfree_skb(skb);
skb = NULL;
} else {
__skb_queue_tail(&list, skb);
}
fput(file);
file = NULL;
break;
}
if (!file)
break;
__skb_queue_tail(&list, skb);
skb = skb_dequeue(head);
}
if (skb_peek(&list)) {
spin_lock_irq(&head->lock);
while ((skb = __skb_dequeue(&list)) != NULL)
__skb_queue_tail(head, skb);
spin_unlock_irq(&head->lock);
}
#else
fput(file);
#endif
}
struct io_file_put {
struct list_head list;
struct file *file;
};
static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
{
struct fixed_file_data *file_data = ref_node->file_data;
struct io_ring_ctx *ctx = file_data->ctx;
struct io_file_put *pfile, *tmp;
list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
list_del(&pfile->list);
io_ring_file_put(ctx, pfile->file);
kfree(pfile);
}
percpu_ref_exit(&ref_node->refs);
kfree(ref_node);
percpu_ref_put(&file_data->refs);
}
static void io_file_put_work(struct work_struct *work)
{
struct io_ring_ctx *ctx;
struct llist_node *node;
ctx = container_of(work, struct io_ring_ctx, file_put_work.work);
node = llist_del_all(&ctx->file_put_llist);
while (node) {
struct fixed_file_ref_node *ref_node;
struct llist_node *next = node->next;
ref_node = llist_entry(node, struct fixed_file_ref_node, llist);
__io_file_put_work(ref_node);
node = next;
}
}
static void io_file_data_ref_zero(struct percpu_ref *ref)
{
struct fixed_file_ref_node *ref_node;
struct fixed_file_data *data;
struct io_ring_ctx *ctx;
bool first_add = false;
int delay = HZ;
ref_node = container_of(ref, struct fixed_file_ref_node, refs);
data = ref_node->file_data;
ctx = data->ctx;
spin_lock_bh(&data->lock);
ref_node->done = true;
while (!list_empty(&data->ref_list)) {
ref_node = list_first_entry(&data->ref_list,
struct fixed_file_ref_node, node);
/* recycle ref nodes in order */
if (!ref_node->done)
break;
list_del(&ref_node->node);
first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist);
}
spin_unlock_bh(&data->lock);
if (percpu_ref_is_dying(&data->refs))
delay = 0;
if (!delay)
mod_delayed_work(system_wq, &ctx->file_put_work, 0);
else if (first_add)
queue_delayed_work(system_wq, &ctx->file_put_work, delay);
}
static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
struct io_ring_ctx *ctx)
{
struct fixed_file_ref_node *ref_node;
ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
if (!ref_node)
return NULL;
if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
0, GFP_KERNEL)) {
kfree(ref_node);
return NULL;
}
INIT_LIST_HEAD(&ref_node->node);
INIT_LIST_HEAD(&ref_node->file_list);
ref_node->file_data = ctx->file_data;
ref_node->done = false;
return ref_node;
}
static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
{
percpu_ref_exit(&ref_node->refs);
kfree(ref_node);
}
static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args)
{
__s32 __user *fds = (__s32 __user *) arg;
unsigned nr_tables, i;
struct file *file;
int fd, ret = -ENOMEM;
struct fixed_file_ref_node *ref_node;
struct fixed_file_data *file_data;
if (ctx->file_data)
return -EBUSY;
if (!nr_args)
return -EINVAL;
if (nr_args > IORING_MAX_FIXED_FILES)
return -EMFILE;
file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
if (!file_data)
return -ENOMEM;
file_data->ctx = ctx;
init_completion(&file_data->done);
INIT_LIST_HEAD(&file_data->ref_list);
spin_lock_init(&file_data->lock);
nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
GFP_KERNEL);
if (!file_data->table)
goto out_free;
if (percpu_ref_init(&file_data->refs, io_file_ref_kill,
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
goto out_free;
if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
goto out_ref;
ctx->file_data = file_data;
for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
struct fixed_file_table *table;
unsigned index;
if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
ret = -EFAULT;
goto out_fput;
}
/* allow sparse sets */
if (fd == -1)
continue;
file = fget(fd);
ret = -EBADF;
if (!file)
goto out_fput;
/*
* Don't allow io_uring instances to be registered. If UNIX
* isn't enabled, then this causes a reference cycle and this
* instance can never get freed. If UNIX is enabled we'll
* handle it just fine, but there's still no point in allowing
* a ring fd as it doesn't support regular read/write anyway.
*/
if (file->f_op == &io_uring_fops) {
fput(file);
goto out_fput;
}
table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT];
index = i & IORING_FILE_TABLE_MASK;
table->files[index] = file;
}
ret = io_sqe_files_scm(ctx);
if (ret) {
io_sqe_files_unregister(ctx);
return ret;
}
ref_node = alloc_fixed_file_ref_node(ctx);
if (!ref_node) {
io_sqe_files_unregister(ctx);
return -ENOMEM;
}
io_sqe_files_set_node(file_data, ref_node);
return ret;
out_fput:
for (i = 0; i < ctx->nr_user_files; i++) {
file = io_file_from_index(ctx, i);
if (file)
fput(file);
}
for (i = 0; i < nr_tables; i++)
kfree(file_data->table[i].files);
ctx->nr_user_files = 0;
out_ref:
percpu_ref_exit(&file_data->refs);
out_free:
kfree(file_data->table);
kfree(file_data);
ctx->file_data = NULL;
return ret;
}
static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
int index)
{
#if defined(CONFIG_UNIX)
struct sock *sock = ctx->ring_sock->sk;
struct sk_buff_head *head = &sock->sk_receive_queue;
struct sk_buff *skb;
/*
* See if we can merge this file into an existing skb SCM_RIGHTS
* file set. If there's no room, fall back to allocating a new skb
* and filling it in.
*/
spin_lock_irq(&head->lock);
skb = skb_peek(head);
if (skb) {
struct scm_fp_list *fpl = UNIXCB(skb).fp;
if (fpl->count < SCM_MAX_FD) {
__skb_unlink(skb, head);
spin_unlock_irq(&head->lock);
fpl->fp[fpl->count] = get_file(file);
unix_inflight(fpl->user, fpl->fp[fpl->count]);
fpl->count++;
spin_lock_irq(&head->lock);
__skb_queue_head(head, skb);
} else {
skb = NULL;
}
}
spin_unlock_irq(&head->lock);
if (skb) {
fput(file);
return 0;
}
return __io_sqe_files_scm(ctx, 1, index);
#else
return 0;
#endif
}
static int io_queue_file_removal(struct fixed_file_data *data,
struct file *file)
{
struct io_file_put *pfile;
struct fixed_file_ref_node *ref_node = data->node;
pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
if (!pfile)
return -ENOMEM;
pfile->file = file;
list_add(&pfile->list, &ref_node->file_list);
return 0;
}
static int __io_sqe_files_update(struct io_ring_ctx *ctx,
struct io_uring_files_update *up,
unsigned nr_args)
{
struct fixed_file_data *data = ctx->file_data;
struct fixed_file_ref_node *ref_node;
struct file *file;
__s32 __user *fds;
int fd, i, err;
__u32 done;
bool needs_switch = false;
if (check_add_overflow(up->offset, nr_args, &done))
return -EOVERFLOW;
if (done > ctx->nr_user_files)
return -EINVAL;
ref_node = alloc_fixed_file_ref_node(ctx);
if (!ref_node)
return -ENOMEM;
done = 0;
fds = u64_to_user_ptr(up->fds);
while (nr_args) {
struct fixed_file_table *table;
unsigned index;
err = 0;
if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
err = -EFAULT;
break;
}
i = array_index_nospec(up->offset, ctx->nr_user_files);
table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
index = i & IORING_FILE_TABLE_MASK;
if (table->files[index]) {
file = table->files[index];
err = io_queue_file_removal(data, file);
if (err)
break;
table->files[index] = NULL;
needs_switch = true;
}
if (fd != -1) {
file = fget(fd);
if (!file) {
err = -EBADF;
break;
}
/*
* Don't allow io_uring instances to be registered. If
* UNIX isn't enabled, then this causes a reference
* cycle and this instance can never get freed. If UNIX
* is enabled we'll handle it just fine, but there's
* still no point in allowing a ring fd as it doesn't
* support regular read/write anyway.
*/
if (file->f_op == &io_uring_fops) {
fput(file);
err = -EBADF;
break;
}
table->files[index] = file;
err = io_sqe_file_register(ctx, file, i);
if (err) {
table->files[index] = NULL;
fput(file);
break;
}
}
nr_args--;
done++;
up->offset++;
}
if (needs_switch) {
percpu_ref_kill(&data->node->refs);
io_sqe_files_set_node(data, ref_node);
} else
destroy_fixed_file_ref_node(ref_node);
return done ? done : err;
}
static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args)
{
struct io_uring_files_update up;
if (!ctx->file_data)
return -ENXIO;
if (!nr_args)
return -EINVAL;
if (copy_from_user(&up, arg, sizeof(up)))
return -EFAULT;
if (up.resv)
return -EINVAL;
return __io_sqe_files_update(ctx, &up, nr_args);
}
static void io_free_work(struct io_wq_work *work)
{
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
/* Consider that io_steal_work() relies on this ref */
io_put_req(req);
}
static int io_init_wq_offload(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
struct io_wq_data data;
struct fd f;
struct io_ring_ctx *ctx_attach;
unsigned int concurrency;
int ret = 0;
data.user = ctx->user;
data.free_work = io_free_work;
data.do_work = io_wq_submit_work;
if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
/* Do QD, or 4 * CPUS, whatever is smallest */
concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
ctx->io_wq = io_wq_create(concurrency, &data);
if (IS_ERR(ctx->io_wq)) {
ret = PTR_ERR(ctx->io_wq);
ctx->io_wq = NULL;
}
return ret;
}
f = fdget(p->wq_fd);
if (!f.file)
return -EBADF;
if (f.file->f_op != &io_uring_fops) {
ret = -EINVAL;
goto out_fput;
}
ctx_attach = f.file->private_data;
/* @io_wq is protected by holding the fd */
if (!io_wq_get(ctx_attach->io_wq, &data)) {
ret = -EINVAL;
goto out_fput;
}
ctx->io_wq = ctx_attach->io_wq;
out_fput:
fdput(f);
return ret;
}
static int io_uring_alloc_task_context(struct task_struct *task)
{
struct io_uring_task *tctx;
int ret;
tctx = kmalloc(sizeof(*tctx), GFP_KERNEL);
if (unlikely(!tctx))
return -ENOMEM;
ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
if (unlikely(ret)) {
kfree(tctx);
return ret;
}
xa_init(&tctx->xa);
init_waitqueue_head(&tctx->wait);
tctx->last = NULL;
atomic_set(&tctx->in_idle, 0);
tctx->sqpoll = false;
io_init_identity(&tctx->__identity);
tctx->identity = &tctx->__identity;
task->io_uring = tctx;
return 0;
}
void __io_uring_free(struct task_struct *tsk)
{
struct io_uring_task *tctx = tsk->io_uring;
WARN_ON_ONCE(!xa_empty(&tctx->xa));
WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1);
if (tctx->identity != &tctx->__identity)
kfree(tctx->identity);
percpu_counter_destroy(&tctx->inflight);
kfree(tctx);
tsk->io_uring = NULL;
}
static int io_sq_offload_create(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
int ret;
if (ctx->flags & IORING_SETUP_SQPOLL) {
struct io_sq_data *sqd;
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_NICE))
goto err;
sqd = io_get_sq_data(p);
if (IS_ERR(sqd)) {
ret = PTR_ERR(sqd);
goto err;
}
ctx->sq_data = sqd;
io_sq_thread_park(sqd);
mutex_lock(&sqd->ctx_lock);
list_add(&ctx->sqd_list, &sqd->ctx_new_list);
mutex_unlock(&sqd->ctx_lock);
io_sq_thread_unpark(sqd);
ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
if (!ctx->sq_thread_idle)
ctx->sq_thread_idle = HZ;
if (sqd->thread)
goto done;
if (p->flags & IORING_SETUP_SQ_AFF) {
int cpu = p->sq_thread_cpu;
ret = -EINVAL;
if (cpu >= nr_cpu_ids)
goto err;
if (!cpu_online(cpu))
goto err;
sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd,
cpu, "io_uring-sq");
} else {
sqd->thread = kthread_create(io_sq_thread, sqd,
"io_uring-sq");
}
if (IS_ERR(sqd->thread)) {
ret = PTR_ERR(sqd->thread);
sqd->thread = NULL;
goto err;
}
ret = io_uring_alloc_task_context(sqd->thread);
if (ret)
goto err;
} else if (p->flags & IORING_SETUP_SQ_AFF) {
/* Can't have SQ_AFF without SQPOLL */
ret = -EINVAL;
goto err;
}
done:
ret = io_init_wq_offload(ctx, p);
if (ret)
goto err;
return 0;
err:
io_finish_async(ctx);
return ret;
}
static void io_sq_offload_start(struct io_ring_ctx *ctx)
{
struct io_sq_data *sqd = ctx->sq_data;
if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd->thread)
wake_up_process(sqd->thread);
}
static inline void __io_unaccount_mem(struct user_struct *user,
unsigned long nr_pages)
{
atomic_long_sub(nr_pages, &user->locked_vm);
}
static inline int __io_account_mem(struct user_struct *user,
unsigned long nr_pages)
{
unsigned long page_limit, cur_pages, new_pages;
/* Don't allow more pages than we can safely lock */
page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
do {
cur_pages = atomic_long_read(&user->locked_vm);
new_pages = cur_pages + nr_pages;
if (new_pages > page_limit)
return -ENOMEM;
} while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
new_pages) != cur_pages);
return 0;
}
static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
enum io_mem_account acct)
{
if (ctx->limit_mem)
__io_unaccount_mem(ctx->user, nr_pages);
if (ctx->mm_account) {
if (acct == ACCT_LOCKED) {
mmap_write_lock(ctx->mm_account);
ctx->mm_account->locked_vm -= nr_pages;
mmap_write_unlock(ctx->mm_account);
}else if (acct == ACCT_PINNED) {
atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
}
}
}
static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
enum io_mem_account acct)
{
int ret;
if (ctx->limit_mem) {
ret = __io_account_mem(ctx->user, nr_pages);
if (ret)
return ret;
}
if (ctx->mm_account) {
if (acct == ACCT_LOCKED) {
mmap_write_lock(ctx->mm_account);
ctx->mm_account->locked_vm += nr_pages;
mmap_write_unlock(ctx->mm_account);
} else if (acct == ACCT_PINNED) {
atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
}
}
return 0;
}
static void io_mem_free(void *ptr)
{
struct page *page;
if (!ptr)
return;
page = virt_to_head_page(ptr);
if (put_page_testzero(page))
free_compound_page(page);
}
static void *io_mem_alloc(size_t size)
{
gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
__GFP_NORETRY;
return (void *) __get_free_pages(gfp_flags, get_order(size));
}
static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
size_t *sq_offset)
{
struct io_rings *rings;
size_t off, sq_array_size;
off = struct_size(rings, cqes, cq_entries);
if (off == SIZE_MAX)
return SIZE_MAX;
#ifdef CONFIG_SMP
off = ALIGN(off, SMP_CACHE_BYTES);
if (off == 0)
return SIZE_MAX;
#endif
if (sq_offset)
*sq_offset = off;
sq_array_size = array_size(sizeof(u32), sq_entries);
if (sq_array_size == SIZE_MAX)
return SIZE_MAX;
if (check_add_overflow(off, sq_array_size, &off))
return SIZE_MAX;
return off;
}
static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
{
size_t pages;
pages = (size_t)1 << get_order(
rings_size(sq_entries, cq_entries, NULL));
pages += (size_t)1 << get_order(
array_size(sizeof(struct io_uring_sqe), sq_entries));
return pages;
}
static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
{
int i, j;
if (!ctx->user_bufs)
return -ENXIO;
for (i = 0; i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
for (j = 0; j < imu->nr_bvecs; j++)
unpin_user_page(imu->bvec[j].bv_page);
if (imu->acct_pages)
io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
kvfree(imu->bvec);
imu->nr_bvecs = 0;
}
kfree(ctx->user_bufs);
ctx->user_bufs = NULL;
ctx->nr_user_bufs = 0;
return 0;
}
static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
void __user *arg, unsigned index)
{
struct iovec __user *src;
#ifdef CONFIG_COMPAT
if (ctx->compat) {
struct compat_iovec __user *ciovs;
struct compat_iovec ciov;
ciovs = (struct compat_iovec __user *) arg;
if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
return -EFAULT;
dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
dst->iov_len = ciov.iov_len;
return 0;
}
#endif
src = (struct iovec __user *) arg;
if (copy_from_user(dst, &src[index], sizeof(*dst)))
return -EFAULT;
return 0;
}
/*
* Not super efficient, but this is just a registration time. And we do cache
* the last compound head, so generally we'll only do a full search if we don't
* match that one.
*
* We check if the given compound head page has already been accounted, to
* avoid double accounting it. This allows us to account the full size of the
* page, not just the constituent pages of a huge page.
*/
static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
int nr_pages, struct page *hpage)
{
int i, j;
/* check current page array */
for (i = 0; i < nr_pages; i++) {
if (!PageCompound(pages[i]))
continue;
if (compound_head(pages[i]) == hpage)
return true;
}
/* check previously registered pages */
for (i = 0; i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
for (j = 0; j < imu->nr_bvecs; j++) {
if (!PageCompound(imu->bvec[j].bv_page))
continue;
if (compound_head(imu->bvec[j].bv_page) == hpage)
return true;
}
}
return false;
}
static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
int nr_pages, struct io_mapped_ubuf *imu,
struct page **last_hpage)
{
int i, ret;
for (i = 0; i < nr_pages; i++) {
if (!PageCompound(pages[i])) {
imu->acct_pages++;
} else {
struct page *hpage;
hpage = compound_head(pages[i]);
if (hpage == *last_hpage)
continue;
*last_hpage = hpage;
if (headpage_already_acct(ctx, pages, i, hpage))
continue;
imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
}
}
if (!imu->acct_pages)
return 0;
ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED);
if (ret)
imu->acct_pages = 0;
return ret;
}
static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args)
{
struct vm_area_struct **vmas = NULL;
struct page **pages = NULL;
struct page *last_hpage = NULL;
int i, j, got_pages = 0;
int ret = -EINVAL;
if (ctx->user_bufs)
return -EBUSY;
if (!nr_args || nr_args > UIO_MAXIOV)
return -EINVAL;
ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
GFP_KERNEL);
if (!ctx->user_bufs)
return -ENOMEM;
for (i = 0; i < nr_args; i++) {
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
unsigned long off, start, end, ubuf;
int pret, nr_pages;
struct iovec iov;
size_t size;
ret = io_copy_iov(ctx, &iov, arg, i);
if (ret)
goto err;
/*
* Don't impose further limits on the size and buffer
* constraints here, we'll -EINVAL later when IO is
* submitted if they are wrong.
*/
ret = -EFAULT;
if (!iov.iov_base || !iov.iov_len)
goto err;
/* arbitrary limit, but we need something */
if (iov.iov_len > SZ_1G)
goto err;
ubuf = (unsigned long) iov.iov_base;
end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
start = ubuf >> PAGE_SHIFT;
nr_pages = end - start;
ret = 0;
if (!pages || nr_pages > got_pages) {
kvfree(vmas);
kvfree(pages);
pages = kvmalloc_array(nr_pages, sizeof(struct page *),
GFP_KERNEL);
vmas = kvmalloc_array(nr_pages,
sizeof(struct vm_area_struct *),
GFP_KERNEL);
if (!pages || !vmas) {
ret = -ENOMEM;
goto err;
}
got_pages = nr_pages;
}
imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
GFP_KERNEL);
ret = -ENOMEM;
if (!imu->bvec)
goto err;
ret = 0;
mmap_read_lock(current->mm);
pret = pin_user_pages(ubuf, nr_pages,
FOLL_WRITE | FOLL_LONGTERM,
pages, vmas);
if (pret == nr_pages) {
/* don't support file backed memory */
for (j = 0; j < nr_pages; j++) {
struct vm_area_struct *vma = vmas[j];
if (vma->vm_file &&
!is_file_hugepages(vma->vm_file)) {
ret = -EOPNOTSUPP;
break;
}
}
} else {
ret = pret < 0 ? pret : -EFAULT;
}
mmap_read_unlock(current->mm);
if (ret) {
/*
* if we did partial map, or found file backed vmas,
* release any pages we did get
*/
if (pret > 0)
unpin_user_pages(pages, pret);
kvfree(imu->bvec);
goto err;
}
ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage);
if (ret) {
unpin_user_pages(pages, pret);
kvfree(imu->bvec);
goto err;
}
off = ubuf & ~PAGE_MASK;
size = iov.iov_len;
for (j = 0; j < nr_pages; j++) {
size_t vec_len;
vec_len = min_t(size_t, size, PAGE_SIZE - off);
imu->bvec[j].bv_page = pages[j];
imu->bvec[j].bv_len = vec_len;
imu->bvec[j].bv_offset = off;
off = 0;
size -= vec_len;
}
/* store original address for later verification */
imu->ubuf = ubuf;
imu->len = iov.iov_len;
imu->nr_bvecs = nr_pages;
ctx->nr_user_bufs++;
}
kvfree(pages);
kvfree(vmas);
return 0;
err:
kvfree(pages);
kvfree(vmas);
io_sqe_buffer_unregister(ctx);
return ret;
}
static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
{
__s32 __user *fds = arg;
int fd;
if (ctx->cq_ev_fd)
return -EBUSY;
if (copy_from_user(&fd, fds, sizeof(*fds)))
return -EFAULT;
ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
if (IS_ERR(ctx->cq_ev_fd)) {
int ret = PTR_ERR(ctx->cq_ev_fd);
ctx->cq_ev_fd = NULL;
return ret;
}
return 0;
}
static int io_eventfd_unregister(struct io_ring_ctx *ctx)
{
if (ctx->cq_ev_fd) {
eventfd_ctx_put(ctx->cq_ev_fd);
ctx->cq_ev_fd = NULL;
return 0;
}
return -ENXIO;
}
static int __io_destroy_buffers(int id, void *p, void *data)
{
struct io_ring_ctx *ctx = data;
struct io_buffer *buf = p;
__io_remove_buffers(ctx, buf, id, -1U);
return 0;
}
static void io_destroy_buffers(struct io_ring_ctx *ctx)
{
idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx);
idr_destroy(&ctx->io_buffer_idr);
}
static void io_ring_ctx_free(struct io_ring_ctx *ctx)
{
io_finish_async(ctx);
io_sqe_buffer_unregister(ctx);
if (ctx->sqo_task) {
put_task_struct(ctx->sqo_task);
ctx->sqo_task = NULL;
mmdrop(ctx->mm_account);
ctx->mm_account = NULL;
}
#ifdef CONFIG_BLK_CGROUP
if (ctx->sqo_blkcg_css)
css_put(ctx->sqo_blkcg_css);
#endif
io_sqe_files_unregister(ctx);
io_eventfd_unregister(ctx);
io_destroy_buffers(ctx);
idr_destroy(&ctx->personality_idr);
#if defined(CONFIG_UNIX)
if (ctx->ring_sock) {
ctx->ring_sock->file = NULL; /* so that iput() is called */
sock_release(ctx->ring_sock);
}
#endif
io_mem_free(ctx->rings);
io_mem_free(ctx->sq_sqes);
percpu_ref_exit(&ctx->refs);
free_uid(ctx->user);
put_cred(ctx->creds);
kfree(ctx->cancel_hash);
kmem_cache_free(req_cachep, ctx->fallback_req);
kfree(ctx);
}
static __poll_t io_uring_poll(struct file *file, poll_table *wait)
{
struct io_ring_ctx *ctx = file->private_data;
__poll_t mask = 0;
poll_wait(file, &ctx->cq_wait, wait);
/*
* synchronizes with barrier from wq_has_sleeper call in
* io_commit_cqring
*/
smp_rmb();
if (!io_sqring_full(ctx))
mask |= EPOLLOUT | EPOLLWRNORM;
io_cqring_overflow_flush(ctx, false, NULL, NULL);
if (io_cqring_events(ctx))
mask |= EPOLLIN | EPOLLRDNORM;
return mask;
}
static int io_uring_fasync(int fd, struct file *file, int on)
{
struct io_ring_ctx *ctx = file->private_data;
return fasync_helper(fd, file, on, &ctx->cq_fasync);
}
static int io_remove_personalities(int id, void *p, void *data)
{
struct io_ring_ctx *ctx = data;
struct io_identity *iod;
iod = idr_remove(&ctx->personality_idr, id);
if (iod) {
put_cred(iod->creds);
if (refcount_dec_and_test(&iod->count))
kfree(iod);
}
return 0;
}
static void io_ring_exit_work(struct work_struct *work)
{
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
exit_work);
/*
* If we're doing polled IO and end up having requests being
* submitted async (out-of-line), then completions can come in while
* we're waiting for refs to drop. We need to reap these manually,
* as nobody else will be looking for them.
*/
do {
__io_uring_cancel_task_requests(ctx, NULL);
} while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
io_ring_ctx_free(ctx);
}
static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
{
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
return req->ctx == data;
}
static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
{
mutex_lock(&ctx->uring_lock);
percpu_ref_kill(&ctx->refs);
if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead))
ctx->sqo_dead = 1;
/* if force is set, the ring is going away. always drop after that */
ctx->cq_overflow_flushed = 1;
if (ctx->rings)
__io_cqring_overflow_flush(ctx, true, NULL, NULL);
mutex_unlock(&ctx->uring_lock);
io_kill_timeouts(ctx, NULL, NULL);
io_poll_remove_all(ctx, NULL, NULL);
if (ctx->io_wq)
io_wq_cancel_cb(ctx->io_wq, io_cancel_ctx_cb, ctx, true);
/* if we failed setting up the ctx, we might not have any rings */
io_iopoll_try_reap_events(ctx);
idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
/*
* Do this upfront, so we won't have a grace period where the ring
* is closed but resources aren't reaped yet. This can cause
* spurious failure in setting up a new ring.
*/
io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
ACCT_LOCKED);
INIT_WORK(&ctx->exit_work, io_ring_exit_work);
/*
* Use system_unbound_wq to avoid spawning tons of event kworkers
* if we're exiting a ton of rings at the same time. It just adds
* noise and overhead, there's no discernable change in runtime
* over using system_wq.
*/
queue_work(system_unbound_wq, &ctx->exit_work);
}
static int io_uring_release(struct inode *inode, struct file *file)
{
struct io_ring_ctx *ctx = file->private_data;
file->private_data = NULL;
io_ring_ctx_wait_and_kill(ctx);
return 0;
}
struct io_task_cancel {
struct task_struct *task;
struct files_struct *files;
};
static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
{
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
struct io_task_cancel *cancel = data;
bool ret;
if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) {
unsigned long flags;
struct io_ring_ctx *ctx = req->ctx;
/* protect against races with linked timeouts */
spin_lock_irqsave(&ctx->completion_lock, flags);
ret = io_match_task(req, cancel->task, cancel->files);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
} else {
ret = io_match_task(req, cancel->task, cancel->files);
}
return ret;
}
static void io_cancel_defer_files(struct io_ring_ctx *ctx,
struct task_struct *task,
struct files_struct *files)
{
struct io_defer_entry *de = NULL;
LIST_HEAD(list);
spin_lock_irq(&ctx->completion_lock);
list_for_each_entry_reverse(de, &ctx->defer_list, list) {
if (io_match_task(de->req, task, files)) {
list_cut_position(&list, &ctx->defer_list, &de->list);
break;
}
}
spin_unlock_irq(&ctx->completion_lock);
while (!list_empty(&list)) {
de = list_first_entry(&list, struct io_defer_entry, list);
list_del_init(&de->list);
req_set_fail_links(de->req);
io_put_req(de->req);
io_req_complete(de->req, -ECANCELED);
kfree(de);
}
}
static void io_uring_cancel_files(struct io_ring_ctx *ctx,
struct task_struct *task,
struct files_struct *files)
{
while (!list_empty_careful(&ctx->inflight_list)) {
struct io_task_cancel cancel = { .task = task, .files = files };
struct io_kiocb *req;
DEFINE_WAIT(wait);
bool found = false;
spin_lock_irq(&ctx->inflight_lock);
list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
if (!io_match_task(req, task, files))
continue;
found = true;
break;
}
if (found)
prepare_to_wait(&task->io_uring->wait, &wait,
TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&ctx->inflight_lock);
/* We need to keep going until we don't find a matching req */
if (!found)
break;
io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
io_poll_remove_all(ctx, task, files);
io_kill_timeouts(ctx, task, files);
io_cqring_overflow_flush(ctx, true, task, files);
/* cancellations _may_ trigger task work */
io_run_task_work();
schedule();
finish_wait(&task->io_uring->wait, &wait);
}
}
static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
struct task_struct *task)
{
while (1) {
struct io_task_cancel cancel = { .task = task, .files = NULL, };
enum io_wq_cancel cret;
bool ret = false;
if (ctx->io_wq) {
cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb,
&cancel, true);
ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
}
/* SQPOLL thread does its own polling */
if (!(ctx->flags & IORING_SETUP_SQPOLL)) {
while (!list_empty_careful(&ctx->iopoll_list)) {
io_iopoll_try_reap_events(ctx);
ret = true;
}
}
ret |= io_poll_remove_all(ctx, task, NULL);
ret |= io_kill_timeouts(ctx, task, NULL);
ret |= io_run_task_work();
if (!ret)
break;
cond_resched();
}
}
static void io_disable_sqo_submit(struct io_ring_ctx *ctx)
{
mutex_lock(&ctx->uring_lock);
ctx->sqo_dead = 1;
mutex_unlock(&ctx->uring_lock);
/* make sure callers enter the ring to get error */
if (ctx->rings)
io_ring_set_wakeup_flag(ctx);
}
/*
* We need to iteratively cancel requests, in case a request has dependent
* hard links. These persist even for failure of cancelations, hence keep
* looping until none are found.
*/
static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
struct files_struct *files)
{
struct task_struct *task = current;
if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
/* for SQPOLL only sqo_task has task notes */
WARN_ON_ONCE(ctx->sqo_task != current);
io_disable_sqo_submit(ctx);
task = ctx->sq_data->thread;
atomic_inc(&task->io_uring->in_idle);
io_sq_thread_park(ctx->sq_data);
}
io_cancel_defer_files(ctx, task, files);
io_cqring_overflow_flush(ctx, true, task, files);
if (!files)
__io_uring_cancel_task_requests(ctx, task);
else
io_uring_cancel_files(ctx, task, files);
if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
atomic_dec(&task->io_uring->in_idle);
/*
* If the files that are going away are the ones in the thread
* identity, clear them out.
*/
if (task->io_uring->identity->files == files)
task->io_uring->identity->files = NULL;
io_sq_thread_unpark(ctx->sq_data);
}
}
/*
* Note that this task has used io_uring. We use it for cancelation purposes.
*/
static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
{
struct io_uring_task *tctx = current->io_uring;
int ret;
if (unlikely(!tctx)) {
ret = io_uring_alloc_task_context(current);
if (unlikely(ret))
return ret;
tctx = current->io_uring;
}
if (tctx->last != file) {
void *old = xa_load(&tctx->xa, (unsigned long)file);
if (!old) {
get_file(file);
ret = xa_err(xa_store(&tctx->xa, (unsigned long)file,
file, GFP_KERNEL));
if (ret) {
fput(file);
return ret;
}
}
tctx->last = file;
}
/*
* This is race safe in that the task itself is doing this, hence it
* cannot be going through the exit/cancel paths at the same time.
* This cannot be modified while exit/cancel is running.
*/
if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL))
tctx->sqpoll = true;
return 0;
}
/*
* Remove this io_uring_file -> task mapping.
*/
static void io_uring_del_task_file(struct file *file)
{
struct io_uring_task *tctx = current->io_uring;
if (tctx->last == file)
tctx->last = NULL;
file = xa_erase(&tctx->xa, (unsigned long)file);
if (file)
fput(file);
}
static void io_uring_remove_task_files(struct io_uring_task *tctx)
{
struct file *file;
unsigned long index;
xa_for_each(&tctx->xa, index, file)
io_uring_del_task_file(file);
}
void __io_uring_files_cancel(struct files_struct *files)
{
struct io_uring_task *tctx = current->io_uring;
struct file *file;
unsigned long index;
/* make sure overflow events are dropped */
atomic_inc(&tctx->in_idle);
xa_for_each(&tctx->xa, index, file)
io_uring_cancel_task_requests(file->private_data, files);
atomic_dec(&tctx->in_idle);
if (files)
io_uring_remove_task_files(tctx);
}
static s64 tctx_inflight(struct io_uring_task *tctx)
{
unsigned long index;
struct file *file;
s64 inflight;
inflight = percpu_counter_sum(&tctx->inflight);
if (!tctx->sqpoll)
return inflight;
/*
* If we have SQPOLL rings, then we need to iterate and find them, and
* add the pending count for those.
*/
xa_for_each(&tctx->xa, index, file) {
struct io_ring_ctx *ctx = file->private_data;
if (ctx->flags & IORING_SETUP_SQPOLL) {
struct io_uring_task *__tctx = ctx->sqo_task->io_uring;
inflight += percpu_counter_sum(&__tctx->inflight);
}
}
return inflight;
}
/*
* Find any io_uring fd that this task has registered or done IO on, and cancel
* requests.
*/
void __io_uring_task_cancel(void)
{
struct io_uring_task *tctx = current->io_uring;
DEFINE_WAIT(wait);
s64 inflight;
/* make sure overflow events are dropped */
atomic_inc(&tctx->in_idle);
/* trigger io_disable_sqo_submit() */
if (tctx->sqpoll)
__io_uring_files_cancel(NULL);
do {
/* read completions before cancelations */
inflight = tctx_inflight(tctx);
if (!inflight)
break;
__io_uring_files_cancel(NULL);
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
/*
* If we've seen completions, retry. This avoids a race where
* a completion comes in before we did prepare_to_wait().
*/
if (inflight != tctx_inflight(tctx))
continue;
schedule();
finish_wait(&tctx->wait, &wait);
} while (1);
finish_wait(&tctx->wait, &wait);
atomic_dec(&tctx->in_idle);
io_uring_remove_task_files(tctx);
}
static int io_uring_flush(struct file *file, void *data)
{
struct io_uring_task *tctx = current->io_uring;
struct io_ring_ctx *ctx = file->private_data;
if (!tctx)
return 0;
/* we should have cancelled and erased it before PF_EXITING */
WARN_ON_ONCE((current->flags & PF_EXITING) &&
xa_load(&tctx->xa, (unsigned long)file));
/*
* fput() is pending, will be 2 if the only other ref is our potential
* task file note. If the task is exiting, drop regardless of count.
*/
if (atomic_long_read(&file->f_count) != 2)
return 0;
if (ctx->flags & IORING_SETUP_SQPOLL) {
/* there is only one file note, which is owned by sqo_task */
WARN_ON_ONCE(ctx->sqo_task != current &&
xa_load(&tctx->xa, (unsigned long)file));
/* sqo_dead check is for when this happens after cancellation */
WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead &&
!xa_load(&tctx->xa, (unsigned long)file));
io_disable_sqo_submit(ctx);
}
if (!(ctx->flags & IORING_SETUP_SQPOLL) || ctx->sqo_task == current)
io_uring_del_task_file(file);
return 0;
}
static void *io_uring_validate_mmap_request(struct file *file,
loff_t pgoff, size_t sz)
{
struct io_ring_ctx *ctx = file->private_data;
loff_t offset = pgoff << PAGE_SHIFT;
struct page *page;
void *ptr;
switch (offset) {
case IORING_OFF_SQ_RING:
case IORING_OFF_CQ_RING:
ptr = ctx->rings;
break;
case IORING_OFF_SQES:
ptr = ctx->sq_sqes;
break;
default:
return ERR_PTR(-EINVAL);
}
page = virt_to_head_page(ptr);
if (sz > page_size(page))
return ERR_PTR(-EINVAL);
return ptr;
}
#ifdef CONFIG_MMU
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
{
size_t sz = vma->vm_end - vma->vm_start;
unsigned long pfn;
void *ptr;
ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
if (IS_ERR(ptr))
return PTR_ERR(ptr);
pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
}
#else /* !CONFIG_MMU */
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
{
return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
}
static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
{
return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
}
static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
void *ptr;
ptr = io_uring_validate_mmap_request(file, pgoff, len);
if (IS_ERR(ptr))
return PTR_ERR(ptr);
return (unsigned long) ptr;
}
#endif /* !CONFIG_MMU */
static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
{
int ret = 0;
DEFINE_WAIT(wait);
do {
if (!io_sqring_full(ctx))
break;
prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
if (unlikely(ctx->sqo_dead)) {
ret = -EOWNERDEAD;
goto out;
}
if (!io_sqring_full(ctx))
break;
schedule();
} while (!signal_pending(current));
finish_wait(&ctx->sqo_sq_wait, &wait);
out:
return ret;
}
static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
struct __kernel_timespec __user **ts,
const sigset_t __user **sig)
{
struct io_uring_getevents_arg arg;
/*
* If EXT_ARG isn't set, then we have no timespec and the argp pointer
* is just a pointer to the sigset_t.
*/
if (!(flags & IORING_ENTER_EXT_ARG)) {
*sig = (const sigset_t __user *) argp;
*ts = NULL;
return 0;
}
/*
* EXT_ARG is set - ensure we agree on the size of it and copy in our
* timespec and sigset_t pointers if good.
*/
if (*argsz != sizeof(arg))
return -EINVAL;
if (copy_from_user(&arg, argp, sizeof(arg)))
return -EFAULT;
*sig = u64_to_user_ptr(arg.sigmask);
*argsz = arg.sigmask_sz;
*ts = u64_to_user_ptr(arg.ts);
return 0;
}
SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
u32, min_complete, u32, flags, const void __user *, argp,
size_t, argsz)
{
struct io_ring_ctx *ctx;
long ret = -EBADF;
int submitted = 0;
struct fd f;
io_run_task_work();
if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG))
return -EINVAL;
f = fdget(fd);
if (!f.file)
return -EBADF;
ret = -EOPNOTSUPP;
if (f.file->f_op != &io_uring_fops)
goto out_fput;
ret = -ENXIO;
ctx = f.file->private_data;
if (!percpu_ref_tryget(&ctx->refs))
goto out_fput;
ret = -EBADFD;
if (ctx->flags & IORING_SETUP_R_DISABLED)
goto out;
/*
* For SQ polling, the thread will do all submissions and completions.
* Just return the requested submit count, and wake the thread if
* we were asked to.
*/
ret = 0;
if (ctx->flags & IORING_SETUP_SQPOLL) {
io_cqring_overflow_flush(ctx, false, NULL, NULL);
ret = -EOWNERDEAD;
if (unlikely(ctx->sqo_dead))
goto out;
if (flags & IORING_ENTER_SQ_WAKEUP)
wake_up(&ctx->sq_data->wait);
if (flags & IORING_ENTER_SQ_WAIT) {
ret = io_sqpoll_wait_sq(ctx);
if (ret)
goto out;
}
submitted = to_submit;
} else if (to_submit) {
ret = io_uring_add_task_file(ctx, f.file);
if (unlikely(ret))
goto out;
mutex_lock(&ctx->uring_lock);
submitted = io_submit_sqes(ctx, to_submit);
mutex_unlock(&ctx->uring_lock);
if (submitted != to_submit)
goto out;
}
if (flags & IORING_ENTER_GETEVENTS) {
const sigset_t __user *sig;
struct __kernel_timespec __user *ts;
ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
if (unlikely(ret))
goto out;
min_complete = min(min_complete, ctx->cq_entries);
/*
* When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
* space applications don't need to do io completion events
* polling again, they can rely on io_sq_thread to do polling
* work, which can reduce cpu usage and uring_lock contention.
*/
if (ctx->flags & IORING_SETUP_IOPOLL &&
!(ctx->flags & IORING_SETUP_SQPOLL)) {
ret = io_iopoll_check(ctx, min_complete);
} else {
ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts);
}
}
out:
percpu_ref_put(&ctx->refs);
out_fput:
fdput(f);
return submitted ? submitted : ret;
}
#ifdef CONFIG_PROC_FS
static int io_uring_show_cred(int id, void *p, void *data)
{
struct io_identity *iod = p;
const struct cred *cred = iod->creds;
struct seq_file *m = data;
struct user_namespace *uns = seq_user_ns(m);
struct group_info *gi;
kernel_cap_t cap;
unsigned __capi;
int g;
seq_printf(m, "%5d\n", id);
seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
seq_puts(m, "\n\tGroups:\t");
gi = cred->group_info;
for (g = 0; g < gi->ngroups; g++) {
seq_put_decimal_ull(m, g ? " " : "",
from_kgid_munged(uns, gi->gid[g]));
}
seq_puts(m, "\n\tCapEff:\t");
cap = cred->cap_effective;
CAP_FOR_EACH_U32(__capi)
seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
seq_putc(m, '\n');
return 0;
}
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
{
struct io_sq_data *sq = NULL;
bool has_lock;
int i;
/*
* Avoid ABBA deadlock between the seq lock and the io_uring mutex,
* since fdinfo case grabs it in the opposite direction of normal use
* cases. If we fail to get the lock, we just don't iterate any
* structures that could be going away outside the io_uring mutex.
*/
has_lock = mutex_trylock(&ctx->uring_lock);
if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL))
sq = ctx->sq_data;
seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
struct fixed_file_table *table;
struct file *f;
table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
f = table->files[i & IORING_FILE_TABLE_MASK];
if (f)
seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
else
seq_printf(m, "%5u: <none>\n", i);
}
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
(unsigned int) buf->len);
}
if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
seq_printf(m, "Personalities:\n");
idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
}
seq_printf(m, "PollList:\n");
spin_lock_irq(&ctx->completion_lock);
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
struct hlist_head *list = &ctx->cancel_hash[i];
struct io_kiocb *req;
hlist_for_each_entry(req, list, hash_node)
seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
req->task->task_works != NULL);
}
spin_unlock_irq(&ctx->completion_lock);
if (has_lock)
mutex_unlock(&ctx->uring_lock);
}
static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
{
struct io_ring_ctx *ctx = f->private_data;
if (percpu_ref_tryget(&ctx->refs)) {
__io_uring_show_fdinfo(ctx, m);
percpu_ref_put(&ctx->refs);
}
}
#endif
static const struct file_operations io_uring_fops = {
.release = io_uring_release,
.flush = io_uring_flush,
.mmap = io_uring_mmap,
#ifndef CONFIG_MMU
.get_unmapped_area = io_uring_nommu_get_unmapped_area,
.mmap_capabilities = io_uring_nommu_mmap_capabilities,
#endif
.poll = io_uring_poll,
.fasync = io_uring_fasync,
#ifdef CONFIG_PROC_FS
.show_fdinfo = io_uring_show_fdinfo,
#endif
};
static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
struct io_rings *rings;
size_t size, sq_array_offset;
/* make sure these are sane, as we already accounted them */
ctx->sq_entries = p->sq_entries;
ctx->cq_entries = p->cq_entries;
size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
if (size == SIZE_MAX)
return -EOVERFLOW;
rings = io_mem_alloc(size);
if (!rings)
return -ENOMEM;
ctx->rings = rings;
ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
rings->sq_ring_mask = p->sq_entries - 1;
rings->cq_ring_mask = p->cq_entries - 1;
rings->sq_ring_entries = p->sq_entries;
rings->cq_ring_entries = p->cq_entries;
ctx->sq_mask = rings->sq_ring_mask;
ctx->cq_mask = rings->cq_ring_mask;
size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
if (size == SIZE_MAX) {
io_mem_free(ctx->rings);
ctx->rings = NULL;
return -EOVERFLOW;
}
ctx->sq_sqes = io_mem_alloc(size);
if (!ctx->sq_sqes) {
io_mem_free(ctx->rings);
ctx->rings = NULL;
return -ENOMEM;
}
return 0;
}
static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
{
int ret, fd;
fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
if (fd < 0)
return fd;
ret = io_uring_add_task_file(ctx, file);
if (ret) {
put_unused_fd(fd);
return ret;
}
fd_install(fd, file);
return fd;
}
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
* fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
* we have to tie this fd to a socket for file garbage collection purposes.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
struct file *file;
#if defined(CONFIG_UNIX)
int ret;
ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
&ctx->ring_sock);
if (ret)
return ERR_PTR(ret);
#endif
file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC);
#if defined(CONFIG_UNIX)
if (IS_ERR(file)) {
sock_release(ctx->ring_sock);
ctx->ring_sock = NULL;
} else {
ctx->ring_sock->file = file;
}
#endif
return file;
}
static int io_uring_create(unsigned entries, struct io_uring_params *p,
struct io_uring_params __user *params)
{
struct user_struct *user = NULL;
struct io_ring_ctx *ctx;
struct file *file;
bool limit_mem;
int ret;
if (!entries)
return -EINVAL;
if (entries > IORING_MAX_ENTRIES) {
if (!(p->flags & IORING_SETUP_CLAMP))
return -EINVAL;
entries = IORING_MAX_ENTRIES;
}
/*
* Use twice as many entries for the CQ ring. It's possible for the
* application to drive a higher depth than the size of the SQ ring,
* since the sqes are only used at submission time. This allows for
* some flexibility in overcommitting a bit. If the application has
* set IORING_SETUP_CQSIZE, it will have passed in the desired number
* of CQ ring entries manually.
*/
p->sq_entries = roundup_pow_of_two(entries);
if (p->flags & IORING_SETUP_CQSIZE) {
/*
* If IORING_SETUP_CQSIZE is set, we do the same roundup
* to a power-of-two, if it isn't already. We do NOT impose
* any cq vs sq ring sizing.
*/
if (!p->cq_entries)
return -EINVAL;
if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
if (!(p->flags & IORING_SETUP_CLAMP))
return -EINVAL;
p->cq_entries = IORING_MAX_CQ_ENTRIES;
}
p->cq_entries = roundup_pow_of_two(p->cq_entries);
if (p->cq_entries < p->sq_entries)
return -EINVAL;
} else {
p->cq_entries = 2 * p->sq_entries;
}
user = get_uid(current_user());
limit_mem = !capable(CAP_IPC_LOCK);
if (limit_mem) {
ret = __io_account_mem(user,
ring_pages(p->sq_entries, p->cq_entries));
if (ret) {
free_uid(user);
return ret;
}
}
ctx = io_ring_ctx_alloc(p);
if (!ctx) {
if (limit_mem)
__io_unaccount_mem(user, ring_pages(p->sq_entries,
p->cq_entries));
free_uid(user);
return -ENOMEM;
}
ctx->compat = in_compat_syscall();
ctx->user = user;
ctx->creds = get_current_cred();
#ifdef CONFIG_AUDIT
ctx->loginuid = current->loginuid;
ctx->sessionid = current->sessionid;
#endif
ctx->sqo_task = get_task_struct(current);
/*
* This is just grabbed for accounting purposes. When a process exits,
* the mm is exited and dropped before the files, hence we need to hang
* on to this mm purely for the purposes of being able to unaccount
* memory (locked/pinned vm). It's not used for anything else.
*/
mmgrab(current->mm);
ctx->mm_account = current->mm;
#ifdef CONFIG_BLK_CGROUP
/*
* The sq thread will belong to the original cgroup it was inited in.
* If the cgroup goes offline (e.g. disabling the io controller), then
* issued bios will be associated with the closest cgroup later in the
* block layer.
*/
rcu_read_lock();
ctx->sqo_blkcg_css = blkcg_css();
ret = css_tryget_online(ctx->sqo_blkcg_css);
rcu_read_unlock();
if (!ret) {
/* don't init against a dying cgroup, have the user try again */
ctx->sqo_blkcg_css = NULL;
ret = -ENODEV;
goto err;
}
#endif
/*
* Account memory _before_ installing the file descriptor. Once
* the descriptor is installed, it can get closed at any time. Also
* do this before hitting the general error path, as ring freeing
* will un-account as well.
*/
io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
ACCT_LOCKED);
ctx->limit_mem = limit_mem;
ret = io_allocate_scq_urings(ctx, p);
if (ret)
goto err;
ret = io_sq_offload_create(ctx, p);
if (ret)
goto err;
if (!(p->flags & IORING_SETUP_R_DISABLED))
io_sq_offload_start(ctx);
memset(&p->sq_off, 0, sizeof(p->sq_off));
p->sq_off.head = offsetof(struct io_rings, sq.head);
p->sq_off.tail = offsetof(struct io_rings, sq.tail);
p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
p->sq_off.flags = offsetof(struct io_rings, sq_flags);
p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
memset(&p->cq_off, 0, sizeof(p->cq_off));
p->cq_off.head = offsetof(struct io_rings, cq.head);
p->cq_off.tail = offsetof(struct io_rings, cq.tail);
p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
p->cq_off.cqes = offsetof(struct io_rings, cqes);
p->cq_off.flags = offsetof(struct io_rings, cq_flags);
p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED |
IORING_FEAT_EXT_ARG;
if (copy_to_user(params, p, sizeof(*p))) {
ret = -EFAULT;
goto err;
}
file = io_uring_get_file(ctx);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto err;
}
/*
* Install ring fd as the very last thing, so we don't risk someone
* having closed it before we finish setup
*/
ret = io_uring_install_fd(ctx, file);
if (ret < 0) {
io_disable_sqo_submit(ctx);
/* fput will clean it up */
fput(file);
return ret;
}
trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
return ret;
err:
io_disable_sqo_submit(ctx);
io_ring_ctx_wait_and_kill(ctx);
return ret;
}
/*
* Sets up an aio uring context, and returns the fd. Applications asks for a
* ring size, we return the actual sq/cq ring sizes (among other things) in the
* params structure passed in.
*/
static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
{
struct io_uring_params p;
int i;
if (copy_from_user(&p, params, sizeof(p)))
return -EFAULT;
for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
if (p.resv[i])
return -EINVAL;
}
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
IORING_SETUP_R_DISABLED))
return -EINVAL;
return io_uring_create(entries, &p, params);
}
SYSCALL_DEFINE2(io_uring_setup, u32, entries,
struct io_uring_params __user *, params)
{
return io_uring_setup(entries, params);
}
static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
{
struct io_uring_probe *p;
size_t size;
int i, ret;
size = struct_size(p, ops, nr_args);
if (size == SIZE_MAX)
return -EOVERFLOW;
p = kzalloc(size, GFP_KERNEL);
if (!p)
return -ENOMEM;
ret = -EFAULT;
if (copy_from_user(p, arg, size))
goto out;
ret = -EINVAL;
if (memchr_inv(p, 0, size))
goto out;
p->last_op = IORING_OP_LAST - 1;
if (nr_args > IORING_OP_LAST)
nr_args = IORING_OP_LAST;
for (i = 0; i < nr_args; i++) {
p->ops[i].op = i;
if (!io_op_defs[i].not_supported)
p->ops[i].flags = IO_URING_OP_SUPPORTED;
}
p->ops_len = i;
ret = 0;
if (copy_to_user(arg, p, size))
ret = -EFAULT;
out:
kfree(p);
return ret;
}
static int io_register_personality(struct io_ring_ctx *ctx)
{
struct io_identity *id;
int ret;
id = kmalloc(sizeof(*id), GFP_KERNEL);
if (unlikely(!id))
return -ENOMEM;
io_init_identity(id);
id->creds = get_current_cred();
ret = idr_alloc_cyclic(&ctx->personality_idr, id, 1, USHRT_MAX, GFP_KERNEL);
if (ret < 0) {
put_cred(id->creds);
kfree(id);
}
return ret;
}
static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
{
struct io_identity *iod;
iod = idr_remove(&ctx->personality_idr, id);
if (iod) {
put_cred(iod->creds);
if (refcount_dec_and_test(&iod->count))
kfree(iod);
return 0;
}
return -EINVAL;
}
static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
unsigned int nr_args)
{
struct io_uring_restriction *res;
size_t size;
int i, ret;
/* Restrictions allowed only if rings started disabled */
if (!(ctx->flags & IORING_SETUP_R_DISABLED))
return -EBADFD;
/* We allow only a single restrictions registration */
if (ctx->restrictions.registered)
return -EBUSY;
if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
return -EINVAL;
size = array_size(nr_args, sizeof(*res));
if (size == SIZE_MAX)
return -EOVERFLOW;
res = memdup_user(arg, size);
if (IS_ERR(res))
return PTR_ERR(res);
ret = 0;
for (i = 0; i < nr_args; i++) {
switch (res[i].opcode) {
case IORING_RESTRICTION_REGISTER_OP:
if (res[i].register_op >= IORING_REGISTER_LAST) {
ret = -EINVAL;
goto out;
}
__set_bit(res[i].register_op,
ctx->restrictions.register_op);
break;
case IORING_RESTRICTION_SQE_OP:
if (res[i].sqe_op >= IORING_OP_LAST) {
ret = -EINVAL;
goto out;
}
__set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
break;
case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
break;
case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
break;
default:
ret = -EINVAL;
goto out;
}
}
out:
/* Reset all restrictions if an error happened */
if (ret != 0)
memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
else
ctx->restrictions.registered = true;
kfree(res);
return ret;
}
static int io_register_enable_rings(struct io_ring_ctx *ctx)
{
if (!(ctx->flags & IORING_SETUP_R_DISABLED))
return -EBADFD;
if (ctx->restrictions.registered)
ctx->restricted = 1;
ctx->flags &= ~IORING_SETUP_R_DISABLED;
io_sq_offload_start(ctx);
return 0;
}
static bool io_register_op_must_quiesce(int op)
{
switch (op) {
case IORING_UNREGISTER_FILES:
case IORING_REGISTER_FILES_UPDATE:
case IORING_REGISTER_PROBE:
case IORING_REGISTER_PERSONALITY:
case IORING_UNREGISTER_PERSONALITY:
return false;
default:
return true;
}
}
static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
void __user *arg, unsigned nr_args)
__releases(ctx->uring_lock)
__acquires(ctx->uring_lock)
{
int ret;
/*
* We're inside the ring mutex, if the ref is already dying, then
* someone else killed the ctx or is already going through
* io_uring_register().
*/
if (percpu_ref_is_dying(&ctx->refs))
return -ENXIO;
if (io_register_op_must_quiesce(opcode)) {
percpu_ref_kill(&ctx->refs);
/*
* Drop uring mutex before waiting for references to exit. If
* another thread is currently inside io_uring_enter() it might
* need to grab the uring_lock to make progress. If we hold it
* here across the drain wait, then we can deadlock. It's safe
* to drop the mutex here, since no new references will come in
* after we've killed the percpu ref.
*/
mutex_unlock(&ctx->uring_lock);
do {
ret = wait_for_completion_interruptible(&ctx->ref_comp);
if (!ret)
break;
ret = io_run_task_work_sig();
if (ret < 0)
break;
} while (1);
mutex_lock(&ctx->uring_lock);
if (ret) {
percpu_ref_resurrect(&ctx->refs);
goto out_quiesce;
}
}
if (ctx->restricted) {
if (opcode >= IORING_REGISTER_LAST) {
ret = -EINVAL;
goto out;
}
if (!test_bit(opcode, ctx->restrictions.register_op)) {
ret = -EACCES;
goto out;
}
}
switch (opcode) {
case IORING_REGISTER_BUFFERS:
ret = io_sqe_buffer_register(ctx, arg, nr_args);
break;
case IORING_UNREGISTER_BUFFERS:
ret = -EINVAL;
if (arg || nr_args)
break;
ret = io_sqe_buffer_unregister(ctx);
break;
case IORING_REGISTER_FILES:
ret = io_sqe_files_register(ctx, arg, nr_args);
break;
case IORING_UNREGISTER_FILES:
ret = -EINVAL;
if (arg || nr_args)
break;
ret = io_sqe_files_unregister(ctx);
break;
case IORING_REGISTER_FILES_UPDATE:
ret = io_sqe_files_update(ctx, arg, nr_args);
break;
case IORING_REGISTER_EVENTFD:
case IORING_REGISTER_EVENTFD_ASYNC:
ret = -EINVAL;
if (nr_args != 1)
break;
ret = io_eventfd_register(ctx, arg);
if (ret)
break;
if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
ctx->eventfd_async = 1;
else
ctx->eventfd_async = 0;
break;
case IORING_UNREGISTER_EVENTFD:
ret = -EINVAL;
if (arg || nr_args)
break;
ret = io_eventfd_unregister(ctx);
break;
case IORING_REGISTER_PROBE:
ret = -EINVAL;
if (!arg || nr_args > 256)
break;
ret = io_probe(ctx, arg, nr_args);
break;
case IORING_REGISTER_PERSONALITY:
ret = -EINVAL;
if (arg || nr_args)
break;
ret = io_register_personality(ctx);
break;
case IORING_UNREGISTER_PERSONALITY:
ret = -EINVAL;
if (arg)
break;
ret = io_unregister_personality(ctx, nr_args);
break;
case IORING_REGISTER_ENABLE_RINGS:
ret = -EINVAL;
if (arg || nr_args)
break;
ret = io_register_enable_rings(ctx);
break;
case IORING_REGISTER_RESTRICTIONS:
ret = io_register_restrictions(ctx, arg, nr_args);
break;
default:
ret = -EINVAL;
break;
}
out:
if (io_register_op_must_quiesce(opcode)) {
/* bring the ctx back to life */
percpu_ref_reinit(&ctx->refs);
out_quiesce:
reinit_completion(&ctx->ref_comp);
}
return ret;
}
SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
void __user *, arg, unsigned int, nr_args)
{
struct io_ring_ctx *ctx;
long ret = -EBADF;
struct fd f;
f = fdget(fd);
if (!f.file)
return -EBADF;
ret = -EOPNOTSUPP;
if (f.file->f_op != &io_uring_fops)
goto out_fput;
ctx = f.file->private_data;
mutex_lock(&ctx->uring_lock);
ret = __io_uring_register(ctx, opcode, arg, nr_args);
mutex_unlock(&ctx->uring_lock);
trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
ctx->cq_ev_fd != NULL, ret);
out_fput:
fdput(f);
return ret;
}
static int __init io_uring_init(void)
{
#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
} while (0)
#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
__BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
BUILD_BUG_SQE_ELEM(0, __u8, opcode);
BUILD_BUG_SQE_ELEM(1, __u8, flags);
BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
BUILD_BUG_SQE_ELEM(4, __s32, fd);
BUILD_BUG_SQE_ELEM(8, __u64, off);
BUILD_BUG_SQE_ELEM(8, __u64, addr2);
BUILD_BUG_SQE_ELEM(16, __u64, addr);
BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
BUILD_BUG_SQE_ELEM(24, __u32, len);
BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
BUILD_BUG_SQE_ELEM(32, __u64, user_data);
BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
BUILD_BUG_SQE_ELEM(42, __u16, personality);
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
return 0;
};
__initcall(io_uring_init);
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку