WSL2-Linux-Kernel/fs/ksmbd/vfs_cache.c

710 строки
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
* Copyright (C) 2019 Samsung Electronics Co., Ltd.
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include "glob.h"
#include "vfs_cache.h"
#include "oplock.h"
#include "vfs.h"
#include "connection.h"
#include "mgmt/tree_connect.h"
#include "mgmt/user_session.h"
#include "smb_common.h"
#define S_DEL_PENDING 1
#define S_DEL_ON_CLS 2
#define S_DEL_ON_CLS_STREAM 8
static unsigned int inode_hash_mask __read_mostly;
static unsigned int inode_hash_shift __read_mostly;
static struct hlist_head *inode_hashtable __read_mostly;
static DEFINE_RWLOCK(inode_hash_lock);
static struct ksmbd_file_table global_ft;
static atomic_long_t fd_limit;
static struct kmem_cache *filp_cache;
void ksmbd_set_fd_limit(unsigned long limit)
{
limit = min(limit, get_max_files());
atomic_long_set(&fd_limit, limit);
}
static bool fd_limit_depleted(void)
{
long v = atomic_long_dec_return(&fd_limit);
if (v >= 0)
return false;
atomic_long_inc(&fd_limit);
return true;
}
static void fd_limit_close(void)
{
atomic_long_inc(&fd_limit);
}
/*
* INODE hash
*/
static unsigned long inode_hash(struct super_block *sb, unsigned long hashval)
{
unsigned long tmp;
tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
L1_CACHE_BYTES;
tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> inode_hash_shift);
return tmp & inode_hash_mask;
}
static struct ksmbd_inode *__ksmbd_inode_lookup(struct inode *inode)
{
struct hlist_head *head = inode_hashtable +
inode_hash(inode->i_sb, inode->i_ino);
struct ksmbd_inode *ci = NULL, *ret_ci = NULL;
hlist_for_each_entry(ci, head, m_hash) {
if (ci->m_inode == inode) {
if (atomic_inc_not_zero(&ci->m_count))
ret_ci = ci;
break;
}
}
return ret_ci;
}
static struct ksmbd_inode *ksmbd_inode_lookup(struct ksmbd_file *fp)
{
return __ksmbd_inode_lookup(file_inode(fp->filp));
}
static struct ksmbd_inode *ksmbd_inode_lookup_by_vfsinode(struct inode *inode)
{
struct ksmbd_inode *ci;
read_lock(&inode_hash_lock);
ci = __ksmbd_inode_lookup(inode);
read_unlock(&inode_hash_lock);
return ci;
}
int ksmbd_query_inode_status(struct inode *inode)
{
struct ksmbd_inode *ci;
int ret = KSMBD_INODE_STATUS_UNKNOWN;
read_lock(&inode_hash_lock);
ci = __ksmbd_inode_lookup(inode);
if (ci) {
ret = KSMBD_INODE_STATUS_OK;
if (ci->m_flags & S_DEL_PENDING)
ret = KSMBD_INODE_STATUS_PENDING_DELETE;
atomic_dec(&ci->m_count);
}
read_unlock(&inode_hash_lock);
return ret;
}
bool ksmbd_inode_pending_delete(struct ksmbd_file *fp)
{
return (fp->f_ci->m_flags & S_DEL_PENDING);
}
void ksmbd_set_inode_pending_delete(struct ksmbd_file *fp)
{
fp->f_ci->m_flags |= S_DEL_PENDING;
}
void ksmbd_clear_inode_pending_delete(struct ksmbd_file *fp)
{
fp->f_ci->m_flags &= ~S_DEL_PENDING;
}
void ksmbd_fd_set_delete_on_close(struct ksmbd_file *fp,
int file_info)
{
if (ksmbd_stream_fd(fp)) {
fp->f_ci->m_flags |= S_DEL_ON_CLS_STREAM;
return;
}
fp->f_ci->m_flags |= S_DEL_ON_CLS;
}
static void ksmbd_inode_hash(struct ksmbd_inode *ci)
{
struct hlist_head *b = inode_hashtable +
inode_hash(ci->m_inode->i_sb, ci->m_inode->i_ino);
hlist_add_head(&ci->m_hash, b);
}
static void ksmbd_inode_unhash(struct ksmbd_inode *ci)
{
write_lock(&inode_hash_lock);
hlist_del_init(&ci->m_hash);
write_unlock(&inode_hash_lock);
}
static int ksmbd_inode_init(struct ksmbd_inode *ci, struct ksmbd_file *fp)
{
ci->m_inode = file_inode(fp->filp);
atomic_set(&ci->m_count, 1);
atomic_set(&ci->op_count, 0);
atomic_set(&ci->sop_count, 0);
ci->m_flags = 0;
ci->m_fattr = 0;
INIT_LIST_HEAD(&ci->m_fp_list);
INIT_LIST_HEAD(&ci->m_op_list);
rwlock_init(&ci->m_lock);
return 0;
}
static struct ksmbd_inode *ksmbd_inode_get(struct ksmbd_file *fp)
{
struct ksmbd_inode *ci, *tmpci;
int rc;
read_lock(&inode_hash_lock);
ci = ksmbd_inode_lookup(fp);
read_unlock(&inode_hash_lock);
if (ci)
return ci;
ci = kmalloc(sizeof(struct ksmbd_inode), GFP_KERNEL);
if (!ci)
return NULL;
rc = ksmbd_inode_init(ci, fp);
if (rc) {
pr_err("inode initialized failed\n");
kfree(ci);
return NULL;
}
write_lock(&inode_hash_lock);
tmpci = ksmbd_inode_lookup(fp);
if (!tmpci) {
ksmbd_inode_hash(ci);
} else {
kfree(ci);
ci = tmpci;
}
write_unlock(&inode_hash_lock);
return ci;
}
static void ksmbd_inode_free(struct ksmbd_inode *ci)
{
ksmbd_inode_unhash(ci);
kfree(ci);
}
static void ksmbd_inode_put(struct ksmbd_inode *ci)
{
if (atomic_dec_and_test(&ci->m_count))
ksmbd_inode_free(ci);
}
int __init ksmbd_inode_hash_init(void)
{
unsigned int loop;
unsigned long numentries = 16384;
unsigned long bucketsize = sizeof(struct hlist_head);
unsigned long size;
inode_hash_shift = ilog2(numentries);
inode_hash_mask = (1 << inode_hash_shift) - 1;
size = bucketsize << inode_hash_shift;
/* init master fp hash table */
inode_hashtable = vmalloc(size);
if (!inode_hashtable)
return -ENOMEM;
for (loop = 0; loop < (1U << inode_hash_shift); loop++)
INIT_HLIST_HEAD(&inode_hashtable[loop]);
return 0;
}
void ksmbd_release_inode_hash(void)
{
vfree(inode_hashtable);
}
static void __ksmbd_inode_close(struct ksmbd_file *fp)
{
struct dentry *dir, *dentry;
struct ksmbd_inode *ci = fp->f_ci;
int err;
struct file *filp;
filp = fp->filp;
if (ksmbd_stream_fd(fp) && (ci->m_flags & S_DEL_ON_CLS_STREAM)) {
ci->m_flags &= ~S_DEL_ON_CLS_STREAM;
err = ksmbd_vfs_remove_xattr(file_mnt_user_ns(filp),
filp->f_path.dentry,
fp->stream.name);
if (err)
pr_err("remove xattr failed : %s\n",
fp->stream.name);
}
if (atomic_dec_and_test(&ci->m_count)) {
write_lock(&ci->m_lock);
if (ci->m_flags & (S_DEL_ON_CLS | S_DEL_PENDING)) {
dentry = filp->f_path.dentry;
dir = dentry->d_parent;
ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
write_unlock(&ci->m_lock);
ksmbd_vfs_unlink(file_mnt_user_ns(filp), dir, dentry);
write_lock(&ci->m_lock);
}
write_unlock(&ci->m_lock);
ksmbd_inode_free(ci);
}
}
static void __ksmbd_remove_durable_fd(struct ksmbd_file *fp)
{
if (!has_file_id(fp->persistent_id))
return;
write_lock(&global_ft.lock);
idr_remove(global_ft.idr, fp->persistent_id);
write_unlock(&global_ft.lock);
}
static void __ksmbd_remove_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
{
if (!has_file_id(fp->volatile_id))
return;
write_lock(&fp->f_ci->m_lock);
list_del_init(&fp->node);
write_unlock(&fp->f_ci->m_lock);
write_lock(&ft->lock);
idr_remove(ft->idr, fp->volatile_id);
write_unlock(&ft->lock);
}
static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
{
struct file *filp;
struct ksmbd_lock *smb_lock, *tmp_lock;
fd_limit_close();
__ksmbd_remove_durable_fd(fp);
__ksmbd_remove_fd(ft, fp);
close_id_del_oplock(fp);
filp = fp->filp;
__ksmbd_inode_close(fp);
if (!IS_ERR_OR_NULL(filp))
fput(filp);
/* because the reference count of fp is 0, it is guaranteed that
* there are not accesses to fp->lock_list.
*/
list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) {
spin_lock(&fp->conn->llist_lock);
list_del(&smb_lock->clist);
spin_unlock(&fp->conn->llist_lock);
list_del(&smb_lock->flist);
locks_free_lock(smb_lock->fl);
kfree(smb_lock);
}
if (ksmbd_stream_fd(fp))
kfree(fp->stream.name);
kmem_cache_free(filp_cache, fp);
}
static struct ksmbd_file *ksmbd_fp_get(struct ksmbd_file *fp)
{
if (!atomic_inc_not_zero(&fp->refcount))
return NULL;
return fp;
}
static struct ksmbd_file *__ksmbd_lookup_fd(struct ksmbd_file_table *ft,
u64 id)
{
struct ksmbd_file *fp;
if (!has_file_id(id))
return NULL;
read_lock(&ft->lock);
fp = idr_find(ft->idr, id);
if (fp)
fp = ksmbd_fp_get(fp);
read_unlock(&ft->lock);
return fp;
}
static void __put_fd_final(struct ksmbd_work *work, struct ksmbd_file *fp)
{
__ksmbd_close_fd(&work->sess->file_table, fp);
atomic_dec(&work->conn->stats.open_files_count);
}
static void set_close_state_blocked_works(struct ksmbd_file *fp)
{
struct ksmbd_work *cancel_work, *ctmp;
spin_lock(&fp->f_lock);
list_for_each_entry_safe(cancel_work, ctmp, &fp->blocked_works,
fp_entry) {
list_del(&cancel_work->fp_entry);
cancel_work->state = KSMBD_WORK_CLOSED;
cancel_work->cancel_fn(cancel_work->cancel_argv);
}
spin_unlock(&fp->f_lock);
}
int ksmbd_close_fd(struct ksmbd_work *work, u64 id)
{
struct ksmbd_file *fp;
struct ksmbd_file_table *ft;
if (!has_file_id(id))
return 0;
ft = &work->sess->file_table;
read_lock(&ft->lock);
fp = idr_find(ft->idr, id);
if (fp) {
set_close_state_blocked_works(fp);
if (!atomic_dec_and_test(&fp->refcount))
fp = NULL;
}
read_unlock(&ft->lock);
if (!fp)
return -EINVAL;
__put_fd_final(work, fp);
return 0;
}
void ksmbd_fd_put(struct ksmbd_work *work, struct ksmbd_file *fp)
{
if (!fp)
return;
if (!atomic_dec_and_test(&fp->refcount))
return;
__put_fd_final(work, fp);
}
static bool __sanity_check(struct ksmbd_tree_connect *tcon, struct ksmbd_file *fp)
{
if (!fp)
return false;
if (fp->tcon != tcon)
return false;
return true;
}
struct ksmbd_file *ksmbd_lookup_foreign_fd(struct ksmbd_work *work, u64 id)
{
return __ksmbd_lookup_fd(&work->sess->file_table, id);
}
struct ksmbd_file *ksmbd_lookup_fd_fast(struct ksmbd_work *work, u64 id)
{
struct ksmbd_file *fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
if (__sanity_check(work->tcon, fp))
return fp;
ksmbd_fd_put(work, fp);
return NULL;
}
struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
u64 pid)
{
struct ksmbd_file *fp;
if (!has_file_id(id)) {
id = work->compound_fid;
pid = work->compound_pfid;
}
fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
if (!__sanity_check(work->tcon, fp)) {
ksmbd_fd_put(work, fp);
return NULL;
}
if (fp->persistent_id != pid) {
ksmbd_fd_put(work, fp);
return NULL;
}
return fp;
}
struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
{
return __ksmbd_lookup_fd(&global_ft, id);
}
struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid)
{
struct ksmbd_file *fp = NULL;
unsigned int id;
read_lock(&global_ft.lock);
idr_for_each_entry(global_ft.idr, fp, id) {
if (!memcmp(fp->create_guid,
cguid,
SMB2_CREATE_GUID_SIZE)) {
fp = ksmbd_fp_get(fp);
break;
}
}
read_unlock(&global_ft.lock);
return fp;
}
struct ksmbd_file *ksmbd_lookup_fd_inode(struct inode *inode)
{
struct ksmbd_file *lfp;
struct ksmbd_inode *ci;
ci = ksmbd_inode_lookup_by_vfsinode(inode);
if (!ci)
return NULL;
read_lock(&ci->m_lock);
list_for_each_entry(lfp, &ci->m_fp_list, node) {
if (inode == file_inode(lfp->filp)) {
atomic_dec(&ci->m_count);
lfp = ksmbd_fp_get(lfp);
read_unlock(&ci->m_lock);
return lfp;
}
}
atomic_dec(&ci->m_count);
read_unlock(&ci->m_lock);
return NULL;
}
#define OPEN_ID_TYPE_VOLATILE_ID (0)
#define OPEN_ID_TYPE_PERSISTENT_ID (1)
static void __open_id_set(struct ksmbd_file *fp, u64 id, int type)
{
if (type == OPEN_ID_TYPE_VOLATILE_ID)
fp->volatile_id = id;
if (type == OPEN_ID_TYPE_PERSISTENT_ID)
fp->persistent_id = id;
}
static int __open_id(struct ksmbd_file_table *ft, struct ksmbd_file *fp,
int type)
{
u64 id = 0;
int ret;
if (type == OPEN_ID_TYPE_VOLATILE_ID && fd_limit_depleted()) {
__open_id_set(fp, KSMBD_NO_FID, type);
return -EMFILE;
}
idr_preload(GFP_KERNEL);
write_lock(&ft->lock);
ret = idr_alloc_cyclic(ft->idr, fp, 0, INT_MAX - 1, GFP_NOWAIT);
if (ret >= 0) {
id = ret;
ret = 0;
} else {
id = KSMBD_NO_FID;
fd_limit_close();
}
__open_id_set(fp, id, type);
write_unlock(&ft->lock);
idr_preload_end();
return ret;
}
unsigned int ksmbd_open_durable_fd(struct ksmbd_file *fp)
{
__open_id(&global_ft, fp, OPEN_ID_TYPE_PERSISTENT_ID);
return fp->persistent_id;
}
struct ksmbd_file *ksmbd_open_fd(struct ksmbd_work *work, struct file *filp)
{
struct ksmbd_file *fp;
int ret;
fp = kmem_cache_zalloc(filp_cache, GFP_KERNEL);
if (!fp) {
pr_err("Failed to allocate memory\n");
return ERR_PTR(-ENOMEM);
}
INIT_LIST_HEAD(&fp->blocked_works);
INIT_LIST_HEAD(&fp->node);
INIT_LIST_HEAD(&fp->lock_list);
spin_lock_init(&fp->f_lock);
atomic_set(&fp->refcount, 1);
fp->filp = filp;
fp->conn = work->conn;
fp->tcon = work->tcon;
fp->volatile_id = KSMBD_NO_FID;
fp->persistent_id = KSMBD_NO_FID;
fp->f_ci = ksmbd_inode_get(fp);
if (!fp->f_ci) {
ret = -ENOMEM;
goto err_out;
}
ret = __open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
if (ret) {
ksmbd_inode_put(fp->f_ci);
goto err_out;
}
atomic_inc(&work->conn->stats.open_files_count);
return fp;
err_out:
kmem_cache_free(filp_cache, fp);
return ERR_PTR(ret);
}
static int
__close_file_table_ids(struct ksmbd_file_table *ft,
struct ksmbd_tree_connect *tcon,
bool (*skip)(struct ksmbd_tree_connect *tcon,
struct ksmbd_file *fp))
{
unsigned int id;
struct ksmbd_file *fp;
int num = 0;
idr_for_each_entry(ft->idr, fp, id) {
if (skip(tcon, fp))
continue;
set_close_state_blocked_works(fp);
if (!atomic_dec_and_test(&fp->refcount))
continue;
__ksmbd_close_fd(ft, fp);
num++;
}
return num;
}
static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
struct ksmbd_file *fp)
{
return fp->tcon != tcon;
}
static bool session_fd_check(struct ksmbd_tree_connect *tcon,
struct ksmbd_file *fp)
{
return false;
}
void ksmbd_close_tree_conn_fds(struct ksmbd_work *work)
{
int num = __close_file_table_ids(&work->sess->file_table,
work->tcon,
tree_conn_fd_check);
atomic_sub(num, &work->conn->stats.open_files_count);
}
void ksmbd_close_session_fds(struct ksmbd_work *work)
{
int num = __close_file_table_ids(&work->sess->file_table,
work->tcon,
session_fd_check);
atomic_sub(num, &work->conn->stats.open_files_count);
}
int ksmbd_init_global_file_table(void)
{
return ksmbd_init_file_table(&global_ft);
}
void ksmbd_free_global_file_table(void)
{
struct ksmbd_file *fp = NULL;
unsigned int id;
idr_for_each_entry(global_ft.idr, fp, id) {
__ksmbd_remove_durable_fd(fp);
kmem_cache_free(filp_cache, fp);
}
ksmbd_destroy_file_table(&global_ft);
}
int ksmbd_init_file_table(struct ksmbd_file_table *ft)
{
ft->idr = kzalloc(sizeof(struct idr), GFP_KERNEL);
if (!ft->idr)
return -ENOMEM;
idr_init(ft->idr);
rwlock_init(&ft->lock);
return 0;
}
void ksmbd_destroy_file_table(struct ksmbd_file_table *ft)
{
if (!ft->idr)
return;
__close_file_table_ids(ft, NULL, session_fd_check);
idr_destroy(ft->idr);
kfree(ft->idr);
ft->idr = NULL;
}
int ksmbd_init_file_cache(void)
{
filp_cache = kmem_cache_create("ksmbd_file_cache",
sizeof(struct ksmbd_file), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!filp_cache)
goto out;
return 0;
out:
pr_err("failed to allocate file cache\n");
return -ENOMEM;
}
void ksmbd_exit_file_cache(void)
{
kmem_cache_destroy(filp_cache);
}