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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/net/sunrpc/rpc_pipe.c

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35 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* net/sunrpc/rpc_pipe.c
*
* Userland/kernel interface for rpcauth_gss.
* Code shamelessly plagiarized from fs/nfsd/nfsctl.c
* and fs/sysfs/inode.c
*
* Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
*
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/fsnotify.h>
#include <linux/kernel.h>
#include <linux/rcupdate.h>
#include <linux/utsname.h>
#include <asm/ioctls.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <linux/seq_file.h>
#include <linux/sunrpc/clnt.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/cache.h>
#include <linux/nsproxy.h>
#include <linux/notifier.h>
#include "netns.h"
#include "sunrpc.h"
#define RPCDBG_FACILITY RPCDBG_DEBUG
#define NET_NAME(net) ((net == &init_net) ? " (init_net)" : "")
static struct file_system_type rpc_pipe_fs_type;
static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
static struct kmem_cache *rpc_inode_cachep __read_mostly;
#define RPC_UPCALL_TIMEOUT (30*HZ)
static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
int rpc_pipefs_notifier_register(struct notifier_block *nb)
{
return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
void (*destroy_msg)(struct rpc_pipe_msg *), int err)
{
struct rpc_pipe_msg *msg;
if (list_empty(head))
return;
do {
msg = list_entry(head->next, struct rpc_pipe_msg, list);
list_del_init(&msg->list);
msg->errno = err;
destroy_msg(msg);
} while (!list_empty(head));
if (waitq)
wake_up(waitq);
}
static void
rpc_timeout_upcall_queue(struct work_struct *work)
{
LIST_HEAD(free_list);
struct rpc_pipe *pipe =
container_of(work, struct rpc_pipe, queue_timeout.work);
void (*destroy_msg)(struct rpc_pipe_msg *);
struct dentry *dentry;
spin_lock(&pipe->lock);
destroy_msg = pipe->ops->destroy_msg;
if (pipe->nreaders == 0) {
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
}
dentry = dget(pipe->dentry);
spin_unlock(&pipe->lock);
rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
&free_list, destroy_msg, -ETIMEDOUT);
dput(dentry);
}
ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
char __user *dst, size_t buflen)
{
char *data = (char *)msg->data + msg->copied;
size_t mlen = min(msg->len - msg->copied, buflen);
unsigned long left;
left = copy_to_user(dst, data, mlen);
if (left == mlen) {
msg->errno = -EFAULT;
return -EFAULT;
}
mlen -= left;
msg->copied += mlen;
msg->errno = 0;
return mlen;
}
EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
/**
* rpc_queue_upcall - queue an upcall message to userspace
* @pipe: upcall pipe on which to queue given message
* @msg: message to queue
*
* Call with an @inode created by rpc_mkpipe() to queue an upcall.
* A userspace process may then later read the upcall by performing a
* read on an open file for this inode. It is up to the caller to
* initialize the fields of @msg (other than @msg->list) appropriately.
*/
int
rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
{
int res = -EPIPE;
struct dentry *dentry;
spin_lock(&pipe->lock);
if (pipe->nreaders) {
list_add_tail(&msg->list, &pipe->pipe);
pipe->pipelen += msg->len;
res = 0;
} else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
if (list_empty(&pipe->pipe))
queue_delayed_work(rpciod_workqueue,
&pipe->queue_timeout,
RPC_UPCALL_TIMEOUT);
list_add_tail(&msg->list, &pipe->pipe);
pipe->pipelen += msg->len;
res = 0;
}
dentry = dget(pipe->dentry);
spin_unlock(&pipe->lock);
if (dentry) {
wake_up(&RPC_I(d_inode(dentry))->waitq);
dput(dentry);
}
return res;
}
EXPORT_SYMBOL_GPL(rpc_queue_upcall);
static inline void
rpc_inode_setowner(struct inode *inode, void *private)
{
RPC_I(inode)->private = private;
}
static void
rpc_close_pipes(struct inode *inode)
{
struct rpc_pipe *pipe = RPC_I(inode)->pipe;
int need_release;
LIST_HEAD(free_list);
inode_lock(inode);
spin_lock(&pipe->lock);
need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
pipe->nreaders = 0;
list_splice_init(&pipe->in_upcall, &free_list);
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
pipe->dentry = NULL;
spin_unlock(&pipe->lock);
rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
pipe->nwriters = 0;
if (need_release && pipe->ops->release_pipe)
pipe->ops->release_pipe(inode);
cancel_delayed_work_sync(&pipe->queue_timeout);
rpc_inode_setowner(inode, NULL);
RPC_I(inode)->pipe = NULL;
inode_unlock(inode);
}
static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
struct rpc_inode *rpci;
rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
if (!rpci)
return NULL;
return &rpci->vfs_inode;
}
static void
rpc_free_inode(struct inode *inode)
{
kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
}
static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
struct rpc_pipe *pipe;
int first_open;
int res = -ENXIO;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL)
goto out;
first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
if (first_open && pipe->ops->open_pipe) {
res = pipe->ops->open_pipe(inode);
if (res)
goto out;
}
if (filp->f_mode & FMODE_READ)
pipe->nreaders++;
if (filp->f_mode & FMODE_WRITE)
pipe->nwriters++;
res = 0;
out:
inode_unlock(inode);
return res;
}
static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
struct rpc_pipe *pipe;
struct rpc_pipe_msg *msg;
int last_close;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL)
goto out;
msg = filp->private_data;
if (msg != NULL) {
spin_lock(&pipe->lock);
msg->errno = -EAGAIN;
list_del_init(&msg->list);
spin_unlock(&pipe->lock);
pipe->ops->destroy_msg(msg);
}
if (filp->f_mode & FMODE_WRITE)
pipe->nwriters --;
if (filp->f_mode & FMODE_READ) {
pipe->nreaders --;
if (pipe->nreaders == 0) {
LIST_HEAD(free_list);
spin_lock(&pipe->lock);
list_splice_init(&pipe->pipe, &free_list);
pipe->pipelen = 0;
spin_unlock(&pipe->lock);
rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
pipe->ops->destroy_msg, -EAGAIN);
}
}
last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
if (last_close && pipe->ops->release_pipe)
pipe->ops->release_pipe(inode);
out:
inode_unlock(inode);
return 0;
}
static ssize_t
rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = file_inode(filp);
struct rpc_pipe *pipe;
struct rpc_pipe_msg *msg;
int res = 0;
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL) {
res = -EPIPE;
goto out_unlock;
}
msg = filp->private_data;
if (msg == NULL) {
spin_lock(&pipe->lock);
if (!list_empty(&pipe->pipe)) {
msg = list_entry(pipe->pipe.next,
struct rpc_pipe_msg,
list);
list_move(&msg->list, &pipe->in_upcall);
pipe->pipelen -= msg->len;
filp->private_data = msg;
msg->copied = 0;
}
spin_unlock(&pipe->lock);
if (msg == NULL)
goto out_unlock;
}
/* NOTE: it is up to the callback to update msg->copied */
res = pipe->ops->upcall(filp, msg, buf, len);
if (res < 0 || msg->len == msg->copied) {
filp->private_data = NULL;
spin_lock(&pipe->lock);
list_del_init(&msg->list);
spin_unlock(&pipe->lock);
pipe->ops->destroy_msg(msg);
}
out_unlock:
inode_unlock(inode);
return res;
}
static ssize_t
rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
struct inode *inode = file_inode(filp);
int res;
inode_lock(inode);
res = -EPIPE;
if (RPC_I(inode)->pipe != NULL)
res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
inode_unlock(inode);
return res;
}
static __poll_t
rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
{
struct inode *inode = file_inode(filp);
struct rpc_inode *rpci = RPC_I(inode);
__poll_t mask = EPOLLOUT | EPOLLWRNORM;
poll_wait(filp, &rpci->waitq, wait);
inode_lock(inode);
if (rpci->pipe == NULL)
mask |= EPOLLERR | EPOLLHUP;
else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
mask |= EPOLLIN | EPOLLRDNORM;
inode_unlock(inode);
return mask;
}
static long
rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct rpc_pipe *pipe;
int len;
switch (cmd) {
case FIONREAD:
inode_lock(inode);
pipe = RPC_I(inode)->pipe;
if (pipe == NULL) {
inode_unlock(inode);
return -EPIPE;
}
spin_lock(&pipe->lock);
len = pipe->pipelen;
if (filp->private_data) {
struct rpc_pipe_msg *msg;
msg = filp->private_data;
len += msg->len - msg->copied;
}
spin_unlock(&pipe->lock);
inode_unlock(inode);
return put_user(len, (int __user *)arg);
default:
return -EINVAL;
}
}
static const struct file_operations rpc_pipe_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = rpc_pipe_read,
.write = rpc_pipe_write,
.poll = rpc_pipe_poll,
.unlocked_ioctl = rpc_pipe_ioctl,
.open = rpc_pipe_open,
.release = rpc_pipe_release,
};
static int
rpc_show_info(struct seq_file *m, void *v)
{
struct rpc_clnt *clnt = m->private;
rcu_read_lock();
seq_printf(m, "RPC server: %s\n",
rcu_dereference(clnt->cl_xprt)->servername);
seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
clnt->cl_prog, clnt->cl_vers);
seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
rcu_read_unlock();
return 0;
}
static int
rpc_info_open(struct inode *inode, struct file *file)
{
struct rpc_clnt *clnt = NULL;
int ret = single_open(file, rpc_show_info, NULL);
if (!ret) {
struct seq_file *m = file->private_data;
spin_lock(&file->f_path.dentry->d_lock);
if (!d_unhashed(file->f_path.dentry))
clnt = RPC_I(inode)->private;
if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
spin_unlock(&file->f_path.dentry->d_lock);
m->private = clnt;
} else {
spin_unlock(&file->f_path.dentry->d_lock);
single_release(inode, file);
ret = -EINVAL;
}
}
return ret;
}
static int
rpc_info_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
if (clnt)
rpc_release_client(clnt);
return single_release(inode, file);
}
static const struct file_operations rpc_info_operations = {
.owner = THIS_MODULE,
.open = rpc_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = rpc_info_release,
};
/*
* Description of fs contents.
*/
struct rpc_filelist {
const char *name;
const struct file_operations *i_fop;
umode_t mode;
};
static struct inode *
rpc_get_inode(struct super_block *sb, umode_t mode)
{
struct inode *inode = new_inode(sb);
if (!inode)
return NULL;
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
switch (mode & S_IFMT) {
case S_IFDIR:
inode->i_fop = &simple_dir_operations;
inode->i_op = &simple_dir_inode_operations;
inc_nlink(inode);
default:
break;
}
return inode;
}
static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
struct inode *inode;
d_drop(dentry);
inode = rpc_get_inode(dir->i_sb, mode);
if (!inode)
goto out_err;
inode->i_ino = iunique(dir->i_sb, 100);
if (i_fop)
inode->i_fop = i_fop;
if (private)
rpc_inode_setowner(inode, private);
d_add(dentry, inode);
return 0;
out_err:
printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
__FILE__, __func__, dentry);
dput(dentry);
return -ENOMEM;
}
static int __rpc_create(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
int err;
err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
if (err)
return err;
fsnotify_create(dir, dentry);
return 0;
}
static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private)
{
int err;
err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
if (err)
return err;
inc_nlink(dir);
fsnotify_mkdir(dir, dentry);
return 0;
}
static void
init_pipe(struct rpc_pipe *pipe)
{
pipe->nreaders = 0;
pipe->nwriters = 0;
INIT_LIST_HEAD(&pipe->in_upcall);
INIT_LIST_HEAD(&pipe->in_downcall);
INIT_LIST_HEAD(&pipe->pipe);
pipe->pipelen = 0;
INIT_DELAYED_WORK(&pipe->queue_timeout,
rpc_timeout_upcall_queue);
pipe->ops = NULL;
spin_lock_init(&pipe->lock);
pipe->dentry = NULL;
}
void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
{
kfree(pipe);
}
EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
{
struct rpc_pipe *pipe;
pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
if (!pipe)
return ERR_PTR(-ENOMEM);
init_pipe(pipe);
pipe->ops = ops;
pipe->flags = flags;
return pipe;
}
EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
umode_t mode,
const struct file_operations *i_fop,
void *private,
struct rpc_pipe *pipe)
{
struct rpc_inode *rpci;
int err;
err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
if (err)
return err;
rpci = RPC_I(d_inode(dentry));
rpci->private = private;
rpci->pipe = pipe;
fsnotify_create(dir, dentry);
return 0;
}
static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
{
int ret;
dget(dentry);
ret = simple_rmdir(dir, dentry);
d_delete(dentry);
dput(dentry);
return ret;
}
static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
{
int ret;
dget(dentry);
ret = simple_unlink(dir, dentry);
d_delete(dentry);
dput(dentry);
return ret;
}
static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
rpc_close_pipes(inode);
return __rpc_unlink(dir, dentry);
}
static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
const char *name)
{
struct qstr q = QSTR_INIT(name, strlen(name));
struct dentry *dentry = d_hash_and_lookup(parent, &q);
if (!dentry) {
dentry = d_alloc(parent, &q);
if (!dentry)
return ERR_PTR(-ENOMEM);
}
if (d_really_is_negative(dentry))
return dentry;
dput(dentry);
return ERR_PTR(-EEXIST);
}
/*
* FIXME: This probably has races.
*/
static void __rpc_depopulate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof)
{
struct inode *dir = d_inode(parent);
struct dentry *dentry;
struct qstr name;
int i;
for (i = start; i < eof; i++) {
name.name = files[i].name;
name.len = strlen(files[i].name);
dentry = d_hash_and_lookup(parent, &name);
if (dentry == NULL)
continue;
if (d_really_is_negative(dentry))
goto next;
switch (d_inode(dentry)->i_mode & S_IFMT) {
default:
BUG();
case S_IFREG:
__rpc_unlink(dir, dentry);
break;
case S_IFDIR:
__rpc_rmdir(dir, dentry);
}
next:
dput(dentry);
}
}
static void rpc_depopulate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof)
{
struct inode *dir = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_CHILD);
__rpc_depopulate(parent, files, start, eof);
inode_unlock(dir);
}
static int rpc_populate(struct dentry *parent,
const struct rpc_filelist *files,
int start, int eof,
void *private)
{
struct inode *dir = d_inode(parent);
struct dentry *dentry;
int i, err;
inode_lock(dir);
for (i = start; i < eof; i++) {
dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_bad;
switch (files[i].mode & S_IFMT) {
default:
BUG();
case S_IFREG:
err = __rpc_create(dir, dentry,
files[i].mode,
files[i].i_fop,
private);
break;
case S_IFDIR:
err = __rpc_mkdir(dir, dentry,
files[i].mode,
NULL,
private);
}
if (err != 0)
goto out_bad;
}
inode_unlock(dir);
return 0;
out_bad:
__rpc_depopulate(parent, files, start, eof);
inode_unlock(dir);
printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
__FILE__, __func__, parent);
return err;
}
static struct dentry *rpc_mkdir_populate(struct dentry *parent,
const char *name, umode_t mode, void *private,
int (*populate)(struct dentry *, void *), void *args_populate)
{
struct dentry *dentry;
struct inode *dir = d_inode(parent);
int error;
inode_lock_nested(dir, I_MUTEX_PARENT);
dentry = __rpc_lookup_create_exclusive(parent, name);
if (IS_ERR(dentry))
goto out;
error = __rpc_mkdir(dir, dentry, mode, NULL, private);
if (error != 0)
goto out_err;
if (populate != NULL) {
error = populate(dentry, args_populate);
if (error)
goto err_rmdir;
}
out:
inode_unlock(dir);
return dentry;
err_rmdir:
__rpc_rmdir(dir, dentry);
out_err:
dentry = ERR_PTR(error);
goto out;
}
static int rpc_rmdir_depopulate(struct dentry *dentry,
void (*depopulate)(struct dentry *))
{
struct dentry *parent;
struct inode *dir;
int error;
parent = dget_parent(dentry);
dir = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_PARENT);
if (depopulate != NULL)
depopulate(dentry);
error = __rpc_rmdir(dir, dentry);
inode_unlock(dir);
dput(parent);
return error;
}
/**
* rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
* @parent: dentry of directory to create new "pipe" in
* @name: name of pipe
* @private: private data to associate with the pipe, for the caller's use
* @pipe: &rpc_pipe containing input parameters
*
* Data is made available for userspace to read by calls to
* rpc_queue_upcall(). The actual reads will result in calls to
* @ops->upcall, which will be called with the file pointer,
* message, and userspace buffer to copy to.
*
* Writes can come at any time, and do not necessarily have to be
* responses to upcalls. They will result in calls to @msg->downcall.
*
* The @private argument passed here will be available to all these methods
* from the file pointer, via RPC_I(file_inode(file))->private.
*/
struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
void *private, struct rpc_pipe *pipe)
{
struct dentry *dentry;
struct inode *dir = d_inode(parent);
umode_t umode = S_IFIFO | 0600;
int err;
if (pipe->ops->upcall == NULL)
umode &= ~0444;
if (pipe->ops->downcall == NULL)
umode &= ~0222;
inode_lock_nested(dir, I_MUTEX_PARENT);
dentry = __rpc_lookup_create_exclusive(parent, name);
if (IS_ERR(dentry))
goto out;
err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
private, pipe);
if (err)
goto out_err;
out:
inode_unlock(dir);
return dentry;
out_err:
dentry = ERR_PTR(err);
printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
__FILE__, __func__, parent, name,
err);
goto out;
}
EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
/**
* rpc_unlink - remove a pipe
* @dentry: dentry for the pipe, as returned from rpc_mkpipe
*
* After this call, lookups will no longer find the pipe, and any
* attempts to read or write using preexisting opens of the pipe will
* return -EPIPE.
*/
int
rpc_unlink(struct dentry *dentry)
{
struct dentry *parent;
struct inode *dir;
int error = 0;
parent = dget_parent(dentry);
dir = d_inode(parent);
inode_lock_nested(dir, I_MUTEX_PARENT);
error = __rpc_rmpipe(dir, dentry);
inode_unlock(dir);
dput(parent);
return error;
}
EXPORT_SYMBOL_GPL(rpc_unlink);
/**
* rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
* @pdh: pointer to struct rpc_pipe_dir_head
*/
void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
{
INIT_LIST_HEAD(&pdh->pdh_entries);
pdh->pdh_dentry = NULL;
}
EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
/**
* rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
* @pdo: pointer to struct rpc_pipe_dir_object
* @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
* @pdo_data: pointer to caller-defined data
*/
void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
const struct rpc_pipe_dir_object_ops *pdo_ops,
void *pdo_data)
{
INIT_LIST_HEAD(&pdo->pdo_head);
pdo->pdo_ops = pdo_ops;
pdo->pdo_data = pdo_data;
}
EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
static int
rpc_add_pipe_dir_object_locked(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
int ret = 0;
if (pdh->pdh_dentry)
ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
if (ret == 0)
list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
return ret;
}
static void
rpc_remove_pipe_dir_object_locked(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
if (pdh->pdh_dentry)
pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
list_del_init(&pdo->pdo_head);
}
/**
* rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @pdo: pointer to struct rpc_pipe_dir_object
*
*/
int
rpc_add_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
int ret = 0;
if (list_empty(&pdo->pdo_head)) {
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
mutex_unlock(&sn->pipefs_sb_lock);
}
return ret;
}
EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
/**
* rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @pdo: pointer to struct rpc_pipe_dir_object
*
*/
void
rpc_remove_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
struct rpc_pipe_dir_object *pdo)
{
if (!list_empty(&pdo->pdo_head)) {
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
mutex_unlock(&sn->pipefs_sb_lock);
}
}
EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
/**
* rpc_find_or_alloc_pipe_dir_object
* @net: pointer to struct net
* @pdh: pointer to struct rpc_pipe_dir_head
* @match: match struct rpc_pipe_dir_object to data
* @alloc: allocate a new struct rpc_pipe_dir_object
* @data: user defined data for match() and alloc()
*
*/
struct rpc_pipe_dir_object *
rpc_find_or_alloc_pipe_dir_object(struct net *net,
struct rpc_pipe_dir_head *pdh,
int (*match)(struct rpc_pipe_dir_object *, void *),
struct rpc_pipe_dir_object *(*alloc)(void *),
void *data)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_pipe_dir_object *pdo;
mutex_lock(&sn->pipefs_sb_lock);
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
if (!match(pdo, data))
continue;
goto out;
}
pdo = alloc(data);
if (!pdo)
goto out;
rpc_add_pipe_dir_object_locked(net, pdh, pdo);
out:
mutex_unlock(&sn->pipefs_sb_lock);
return pdo;
}
EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
static void
rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
{
struct rpc_pipe_dir_object *pdo;
struct dentry *dir = pdh->pdh_dentry;
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
pdo->pdo_ops->create(dir, pdo);
}
static void
rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
{
struct rpc_pipe_dir_object *pdo;
struct dentry *dir = pdh->pdh_dentry;
list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
pdo->pdo_ops->destroy(dir, pdo);
}
enum {
RPCAUTH_info,
RPCAUTH_EOF
};
static const struct rpc_filelist authfiles[] = {
[RPCAUTH_info] = {
.name = "info",
.i_fop = &rpc_info_operations,
.mode = S_IFREG | 0400,
},
};
static int rpc_clntdir_populate(struct dentry *dentry, void *private)
{
return rpc_populate(dentry,
authfiles, RPCAUTH_info, RPCAUTH_EOF,
private);
}
static void rpc_clntdir_depopulate(struct dentry *dentry)
{
rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
}
/**
* rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
* @dentry: the parent of new directory
* @name: the name of new directory
* @rpc_client: rpc client to associate with this directory
*
* This creates a directory at the given @path associated with
* @rpc_clnt, which will contain a file named "info" with some basic
* information about the client, together with any "pipes" that may
* later be created using rpc_mkpipe().
*/
struct dentry *rpc_create_client_dir(struct dentry *dentry,
const char *name,
struct rpc_clnt *rpc_client)
{
struct dentry *ret;
ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
rpc_clntdir_populate, rpc_client);
if (!IS_ERR(ret)) {
rpc_client->cl_pipedir_objects.pdh_dentry = ret;
rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
}
return ret;
}
/**
* rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
* @rpc_client: rpc_client for the pipe
*/
int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
{
struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
if (dentry == NULL)
return 0;
rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
}
static const struct rpc_filelist cache_pipefs_files[3] = {
[0] = {
.name = "channel",
.i_fop = &cache_file_operations_pipefs,
.mode = S_IFREG | 0600,
},
[1] = {
.name = "content",
.i_fop = &content_file_operations_pipefs,
.mode = S_IFREG | 0400,
},
[2] = {
.name = "flush",
.i_fop = &cache_flush_operations_pipefs,
.mode = S_IFREG | 0600,
},
};
static int rpc_cachedir_populate(struct dentry *dentry, void *private)
{
return rpc_populate(dentry,
cache_pipefs_files, 0, 3,
private);
}
static void rpc_cachedir_depopulate(struct dentry *dentry)
{
rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
}
struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
umode_t umode, struct cache_detail *cd)
{
return rpc_mkdir_populate(parent, name, umode, NULL,
rpc_cachedir_populate, cd);
}
void rpc_remove_cache_dir(struct dentry *dentry)
{
rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
}
/*
* populate the filesystem
*/
static const struct super_operations s_ops = {
.alloc_inode = rpc_alloc_inode,
.free_inode = rpc_free_inode,
.statfs = simple_statfs,
};
#define RPCAUTH_GSSMAGIC 0x67596969
/*
* We have a single directory with 1 node in it.
*/
enum {
RPCAUTH_lockd,
RPCAUTH_mount,
RPCAUTH_nfs,
RPCAUTH_portmap,
RPCAUTH_statd,
RPCAUTH_nfsd4_cb,
RPCAUTH_cache,
RPCAUTH_nfsd,
RPCAUTH_gssd,
RPCAUTH_RootEOF
};
static const struct rpc_filelist files[] = {
[RPCAUTH_lockd] = {
.name = "lockd",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_mount] = {
.name = "mount",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_nfs] = {
.name = "nfs",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_portmap] = {
.name = "portmap",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_statd] = {
.name = "statd",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_nfsd4_cb] = {
.name = "nfsd4_cb",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_cache] = {
.name = "cache",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_nfsd] = {
.name = "nfsd",
.mode = S_IFDIR | 0555,
},
[RPCAUTH_gssd] = {
.name = "gssd",
.mode = S_IFDIR | 0555,
},
};
/*
* This call can be used only in RPC pipefs mount notification hooks.
*/
struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
const unsigned char *dir_name)
{
struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
return d_hash_and_lookup(sb->s_root, &dir);
}
EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
int rpc_pipefs_init_net(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
if (IS_ERR(sn->gssd_dummy))
return PTR_ERR(sn->gssd_dummy);
mutex_init(&sn->pipefs_sb_lock);
sn->pipe_version = -1;
return 0;
}
void rpc_pipefs_exit_net(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
rpc_destroy_pipe_data(sn->gssd_dummy);
}
/*
* This call will be used for per network namespace operations calls.
* Note: Function will be returned with pipefs_sb_lock taken if superblock was
* found. This lock have to be released by rpc_put_sb_net() when all operations
* will be completed.
*/
struct super_block *rpc_get_sb_net(const struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
if (sn->pipefs_sb)
return sn->pipefs_sb;
mutex_unlock(&sn->pipefs_sb_lock);
return NULL;
}
EXPORT_SYMBOL_GPL(rpc_get_sb_net);
void rpc_put_sb_net(const struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
WARN_ON(sn->pipefs_sb == NULL);
mutex_unlock(&sn->pipefs_sb_lock);
}
EXPORT_SYMBOL_GPL(rpc_put_sb_net);
static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
[0] = {
.name = "clntXX",
.mode = S_IFDIR | 0555,
},
};
static ssize_t
dummy_downcall(struct file *filp, const char __user *src, size_t len)
{
return -EINVAL;
}
static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = dummy_downcall,
};
/*
* Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
* that it will ever use this info to handle an upcall, but rpc.gssd expects
* that this file will be there and have a certain format.
*/
static int
rpc_dummy_info_show(struct seq_file *m, void *v)
{
seq_printf(m, "RPC server: %s\n", utsname()->nodename);
seq_printf(m, "service: foo (1) version 0\n");
seq_printf(m, "address: 127.0.0.1\n");
seq_printf(m, "protocol: tcp\n");
seq_printf(m, "port: 0\n");
return 0;
}
DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
static const struct rpc_filelist gssd_dummy_info_file[] = {
[0] = {
.name = "info",
.i_fop = &rpc_dummy_info_fops,
.mode = S_IFREG | 0400,
},
};
/**
* rpc_gssd_dummy_populate - create a dummy gssd pipe
* @root: root of the rpc_pipefs filesystem
* @pipe_data: pipe data created when netns is initialized
*
* Create a dummy set of directories and a pipe that gssd can hold open to
* indicate that it is up and running.
*/
static struct dentry *
rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
{
int ret = 0;
struct dentry *gssd_dentry;
struct dentry *clnt_dentry = NULL;
struct dentry *pipe_dentry = NULL;
struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
strlen(files[RPCAUTH_gssd].name));
/* We should never get this far if "gssd" doesn't exist */
gssd_dentry = d_hash_and_lookup(root, &q);
if (!gssd_dentry)
return ERR_PTR(-ENOENT);
ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
if (ret) {
pipe_dentry = ERR_PTR(ret);
goto out;
}
q.name = gssd_dummy_clnt_dir[0].name;
q.len = strlen(gssd_dummy_clnt_dir[0].name);
clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
if (!clnt_dentry) {
pipe_dentry = ERR_PTR(-ENOENT);
goto out;
}
ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
if (ret) {
__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
pipe_dentry = ERR_PTR(ret);
goto out;
}
pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
if (IS_ERR(pipe_dentry)) {
__rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
}
out:
dput(clnt_dentry);
dput(gssd_dentry);
return pipe_dentry;
}
static void
rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
{
struct dentry *clnt_dir = pipe_dentry->d_parent;
struct dentry *gssd_dir = clnt_dir->d_parent;
dget(pipe_dentry);
__rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
__rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
__rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
dput(pipe_dentry);
}
static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
struct dentry *root, *gssd_dentry;
struct net *net = get_net(sb->s_fs_info);
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
int err;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = RPCAUTH_GSSMAGIC;
sb->s_op = &s_ops;
sb->s_d_op = &simple_dentry_operations;
sb->s_time_gran = 1;
inode = rpc_get_inode(sb, S_IFDIR | 0555);
sb->s_root = root = d_make_root(inode);
if (!root)
return -ENOMEM;
if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
return -ENOMEM;
gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
if (IS_ERR(gssd_dentry)) {
__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
return PTR_ERR(gssd_dentry);
}
dprintk("RPC: sending pipefs MOUNT notification for net %x%s\n",
net->ns.inum, NET_NAME(net));
mutex_lock(&sn->pipefs_sb_lock);
sn->pipefs_sb = sb;
err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_MOUNT,
sb);
if (err)
goto err_depopulate;
mutex_unlock(&sn->pipefs_sb_lock);
return 0;
err_depopulate:
rpc_gssd_dummy_depopulate(gssd_dentry);
blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
sn->pipefs_sb = NULL;
__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
mutex_unlock(&sn->pipefs_sb_lock);
return err;
}
bool
gssd_running(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_pipe *pipe = sn->gssd_dummy;
return pipe->nreaders || pipe->nwriters;
}
EXPORT_SYMBOL_GPL(gssd_running);
static struct dentry *
rpc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct net *net = current->nsproxy->net_ns;
return mount_ns(fs_type, flags, data, net, net->user_ns, rpc_fill_super);
}
static void rpc_kill_sb(struct super_block *sb)
{
struct net *net = sb->s_fs_info;
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
mutex_lock(&sn->pipefs_sb_lock);
if (sn->pipefs_sb != sb) {
mutex_unlock(&sn->pipefs_sb_lock);
goto out;
}
sn->pipefs_sb = NULL;
dprintk("RPC: sending pipefs UMOUNT notification for net %x%s\n",
net->ns.inum, NET_NAME(net));
blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
mutex_unlock(&sn->pipefs_sb_lock);
out:
kill_litter_super(sb);
put_net(net);
}
static struct file_system_type rpc_pipe_fs_type = {
.owner = THIS_MODULE,
.name = "rpc_pipefs",
.mount = rpc_mount,
.kill_sb = rpc_kill_sb,
};
MODULE_ALIAS_FS("rpc_pipefs");
MODULE_ALIAS("rpc_pipefs");
static void
init_once(void *foo)
{
struct rpc_inode *rpci = (struct rpc_inode *) foo;
inode_init_once(&rpci->vfs_inode);
rpci->private = NULL;
rpci->pipe = NULL;
init_waitqueue_head(&rpci->waitq);
}
int register_rpc_pipefs(void)
{
int err;
rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
sizeof(struct rpc_inode),
0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD|SLAB_ACCOUNT),
init_once);
if (!rpc_inode_cachep)
return -ENOMEM;
err = rpc_clients_notifier_register();
if (err)
goto err_notifier;
err = register_filesystem(&rpc_pipe_fs_type);
if (err)
goto err_register;
return 0;
err_register:
rpc_clients_notifier_unregister();
err_notifier:
kmem_cache_destroy(rpc_inode_cachep);
return err;
}
void unregister_rpc_pipefs(void)
{
rpc_clients_notifier_unregister();
kmem_cache_destroy(rpc_inode_cachep);
unregister_filesystem(&rpc_pipe_fs_type);
}
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