// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* fs/inotify_user.c - inotify support for userspace
|
*
|
* Authors:
|
* John McCutchan <ttb@tentacle.dhs.org>
|
* Robert Love <rml@novell.com>
|
*
|
* Copyright (C) 2005 John McCutchan
|
* Copyright 2006 Hewlett-Packard Development Company, L.P.
|
*
|
* Copyright (C) 2009 Eric Paris <Red Hat Inc>
|
* inotify was largely rewriten to make use of the fsnotify infrastructure
|
*/
|
|
#include <linux/file.h>
|
#include <linux/fs.h> /* struct inode */
|
#include <linux/fsnotify_backend.h>
|
#include <linux/idr.h>
|
#include <linux/init.h> /* fs_initcall */
|
#include <linux/inotify.h>
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#include <linux/kernel.h> /* roundup() */
|
#include <linux/namei.h> /* LOOKUP_FOLLOW */
|
#include <linux/sched/signal.h>
|
#include <linux/slab.h> /* struct kmem_cache */
|
#include <linux/syscalls.h>
|
#include <linux/types.h>
|
#include <linux/anon_inodes.h>
|
#include <linux/uaccess.h>
|
#include <linux/poll.h>
|
#include <linux/wait.h>
|
#include <linux/memcontrol.h>
|
#include <linux/security.h>
|
|
#include "inotify.h"
|
#include "../fdinfo.h"
|
|
#include <asm/ioctls.h>
|
|
/* configurable via /proc/sys/fs/inotify/ */
|
static int inotify_max_queued_events __read_mostly;
|
|
struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
|
|
#ifdef CONFIG_SYSCTL
|
|
#include <linux/sysctl.h>
|
|
struct ctl_table inotify_table[] = {
|
{
|
.procname = "max_user_instances",
|
.data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES],
|
.maxlen = sizeof(int),
|
.mode = 0644,
|
.proc_handler = proc_dointvec_minmax,
|
.extra1 = SYSCTL_ZERO,
|
},
|
{
|
.procname = "max_user_watches",
|
.data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES],
|
.maxlen = sizeof(int),
|
.mode = 0644,
|
.proc_handler = proc_dointvec_minmax,
|
.extra1 = SYSCTL_ZERO,
|
},
|
{
|
.procname = "max_queued_events",
|
.data = &inotify_max_queued_events,
|
.maxlen = sizeof(int),
|
.mode = 0644,
|
.proc_handler = proc_dointvec_minmax,
|
.extra1 = SYSCTL_ZERO
|
},
|
{ }
|
};
|
#endif /* CONFIG_SYSCTL */
|
|
static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
|
{
|
__u32 mask;
|
|
/*
|
* Everything should accept their own ignored and should receive events
|
* when the inode is unmounted. All directories care about children.
|
*/
|
mask = (FS_IN_IGNORED | FS_UNMOUNT);
|
if (S_ISDIR(inode->i_mode))
|
mask |= FS_EVENT_ON_CHILD;
|
|
/* mask off the flags used to open the fd */
|
mask |= (arg & INOTIFY_USER_MASK);
|
|
return mask;
|
}
|
|
static inline u32 inotify_mask_to_arg(__u32 mask)
|
{
|
return mask & (IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT | IN_IGNORED |
|
IN_Q_OVERFLOW);
|
}
|
|
/* intofiy userspace file descriptor functions */
|
static __poll_t inotify_poll(struct file *file, poll_table *wait)
|
{
|
struct fsnotify_group *group = file->private_data;
|
__poll_t ret = 0;
|
|
poll_wait(file, &group->notification_waitq, wait);
|
spin_lock(&group->notification_lock);
|
if (!fsnotify_notify_queue_is_empty(group))
|
ret = EPOLLIN | EPOLLRDNORM;
|
spin_unlock(&group->notification_lock);
|
|
return ret;
|
}
|
|
static int round_event_name_len(struct fsnotify_event *fsn_event)
|
{
|
struct inotify_event_info *event;
|
|
event = INOTIFY_E(fsn_event);
|
if (!event->name_len)
|
return 0;
|
return roundup(event->name_len + 1, sizeof(struct inotify_event));
|
}
|
|
/*
|
* Get an inotify_kernel_event if one exists and is small
|
* enough to fit in "count". Return an error pointer if
|
* not large enough.
|
*
|
* Called with the group->notification_lock held.
|
*/
|
static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
|
size_t count)
|
{
|
size_t event_size = sizeof(struct inotify_event);
|
struct fsnotify_event *event;
|
|
if (fsnotify_notify_queue_is_empty(group))
|
return NULL;
|
|
event = fsnotify_peek_first_event(group);
|
|
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
|
|
event_size += round_event_name_len(event);
|
if (event_size > count)
|
return ERR_PTR(-EINVAL);
|
|
/* held the notification_lock the whole time, so this is the
|
* same event we peeked above */
|
fsnotify_remove_first_event(group);
|
|
return event;
|
}
|
|
/*
|
* Copy an event to user space, returning how much we copied.
|
*
|
* We already checked that the event size is smaller than the
|
* buffer we had in "get_one_event()" above.
|
*/
|
static ssize_t copy_event_to_user(struct fsnotify_group *group,
|
struct fsnotify_event *fsn_event,
|
char __user *buf)
|
{
|
struct inotify_event inotify_event;
|
struct inotify_event_info *event;
|
size_t event_size = sizeof(struct inotify_event);
|
size_t name_len;
|
size_t pad_name_len;
|
|
pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event);
|
|
event = INOTIFY_E(fsn_event);
|
name_len = event->name_len;
|
/*
|
* round up name length so it is a multiple of event_size
|
* plus an extra byte for the terminating '\0'.
|
*/
|
pad_name_len = round_event_name_len(fsn_event);
|
inotify_event.len = pad_name_len;
|
inotify_event.mask = inotify_mask_to_arg(event->mask);
|
inotify_event.wd = event->wd;
|
inotify_event.cookie = event->sync_cookie;
|
|
/* send the main event */
|
if (copy_to_user(buf, &inotify_event, event_size))
|
return -EFAULT;
|
|
buf += event_size;
|
|
/*
|
* fsnotify only stores the pathname, so here we have to send the pathname
|
* and then pad that pathname out to a multiple of sizeof(inotify_event)
|
* with zeros.
|
*/
|
if (pad_name_len) {
|
/* copy the path name */
|
if (copy_to_user(buf, event->name, name_len))
|
return -EFAULT;
|
buf += name_len;
|
|
/* fill userspace with 0's */
|
if (clear_user(buf, pad_name_len - name_len))
|
return -EFAULT;
|
event_size += pad_name_len;
|
}
|
|
return event_size;
|
}
|
|
static ssize_t inotify_read(struct file *file, char __user *buf,
|
size_t count, loff_t *pos)
|
{
|
struct fsnotify_group *group;
|
struct fsnotify_event *kevent;
|
char __user *start;
|
int ret;
|
DEFINE_WAIT_FUNC(wait, woken_wake_function);
|
|
start = buf;
|
group = file->private_data;
|
|
add_wait_queue(&group->notification_waitq, &wait);
|
while (1) {
|
spin_lock(&group->notification_lock);
|
kevent = get_one_event(group, count);
|
spin_unlock(&group->notification_lock);
|
|
pr_debug("%s: group=%p kevent=%p\n", __func__, group, kevent);
|
|
if (kevent) {
|
ret = PTR_ERR(kevent);
|
if (IS_ERR(kevent))
|
break;
|
ret = copy_event_to_user(group, kevent, buf);
|
fsnotify_destroy_event(group, kevent);
|
if (ret < 0)
|
break;
|
buf += ret;
|
count -= ret;
|
continue;
|
}
|
|
ret = -EAGAIN;
|
if (file->f_flags & O_NONBLOCK)
|
break;
|
ret = -ERESTARTSYS;
|
if (signal_pending(current))
|
break;
|
|
if (start != buf)
|
break;
|
|
wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
|
}
|
remove_wait_queue(&group->notification_waitq, &wait);
|
|
if (start != buf && ret != -EFAULT)
|
ret = buf - start;
|
return ret;
|
}
|
|
static int inotify_release(struct inode *ignored, struct file *file)
|
{
|
struct fsnotify_group *group = file->private_data;
|
|
pr_debug("%s: group=%p\n", __func__, group);
|
|
/* free this group, matching get was inotify_init->fsnotify_obtain_group */
|
fsnotify_destroy_group(group);
|
|
return 0;
|
}
|
|
static long inotify_ioctl(struct file *file, unsigned int cmd,
|
unsigned long arg)
|
{
|
struct fsnotify_group *group;
|
struct fsnotify_event *fsn_event;
|
void __user *p;
|
int ret = -ENOTTY;
|
size_t send_len = 0;
|
|
group = file->private_data;
|
p = (void __user *) arg;
|
|
pr_debug("%s: group=%p cmd=%u\n", __func__, group, cmd);
|
|
switch (cmd) {
|
case FIONREAD:
|
spin_lock(&group->notification_lock);
|
list_for_each_entry(fsn_event, &group->notification_list,
|
list) {
|
send_len += sizeof(struct inotify_event);
|
send_len += round_event_name_len(fsn_event);
|
}
|
spin_unlock(&group->notification_lock);
|
ret = put_user(send_len, (int __user *) p);
|
break;
|
#ifdef CONFIG_CHECKPOINT_RESTORE
|
case INOTIFY_IOC_SETNEXTWD:
|
ret = -EINVAL;
|
if (arg >= 1 && arg <= INT_MAX) {
|
struct inotify_group_private_data *data;
|
|
data = &group->inotify_data;
|
spin_lock(&data->idr_lock);
|
idr_set_cursor(&data->idr, (unsigned int)arg);
|
spin_unlock(&data->idr_lock);
|
ret = 0;
|
}
|
break;
|
#endif /* CONFIG_CHECKPOINT_RESTORE */
|
}
|
|
return ret;
|
}
|
|
static const struct file_operations inotify_fops = {
|
.show_fdinfo = inotify_show_fdinfo,
|
.poll = inotify_poll,
|
.read = inotify_read,
|
.fasync = fsnotify_fasync,
|
.release = inotify_release,
|
.unlocked_ioctl = inotify_ioctl,
|
.compat_ioctl = inotify_ioctl,
|
.llseek = noop_llseek,
|
};
|
|
|
/*
|
* find_inode - resolve a user-given path to a specific inode
|
*/
|
static int inotify_find_inode(const char __user *dirname, struct path *path,
|
unsigned int flags, __u64 mask)
|
{
|
int error;
|
|
error = user_path_at(AT_FDCWD, dirname, flags, path);
|
if (error)
|
return error;
|
/* you can only watch an inode if you have read permissions on it */
|
error = inode_permission(path->dentry->d_inode, MAY_READ);
|
if (error) {
|
path_put(path);
|
return error;
|
}
|
error = security_path_notify(path, mask,
|
FSNOTIFY_OBJ_TYPE_INODE);
|
if (error)
|
path_put(path);
|
|
return error;
|
}
|
|
static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
|
struct inotify_inode_mark *i_mark)
|
{
|
int ret;
|
|
idr_preload(GFP_KERNEL);
|
spin_lock(idr_lock);
|
|
ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT);
|
if (ret >= 0) {
|
/* we added the mark to the idr, take a reference */
|
i_mark->wd = ret;
|
fsnotify_get_mark(&i_mark->fsn_mark);
|
}
|
|
spin_unlock(idr_lock);
|
idr_preload_end();
|
return ret < 0 ? ret : 0;
|
}
|
|
static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group,
|
int wd)
|
{
|
struct idr *idr = &group->inotify_data.idr;
|
spinlock_t *idr_lock = &group->inotify_data.idr_lock;
|
struct inotify_inode_mark *i_mark;
|
|
assert_spin_locked(idr_lock);
|
|
i_mark = idr_find(idr, wd);
|
if (i_mark) {
|
struct fsnotify_mark *fsn_mark = &i_mark->fsn_mark;
|
|
fsnotify_get_mark(fsn_mark);
|
/* One ref for being in the idr, one ref we just took */
|
BUG_ON(refcount_read(&fsn_mark->refcnt) < 2);
|
}
|
|
return i_mark;
|
}
|
|
static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group,
|
int wd)
|
{
|
struct inotify_inode_mark *i_mark;
|
spinlock_t *idr_lock = &group->inotify_data.idr_lock;
|
|
spin_lock(idr_lock);
|
i_mark = inotify_idr_find_locked(group, wd);
|
spin_unlock(idr_lock);
|
|
return i_mark;
|
}
|
|
/*
|
* Remove the mark from the idr (if present) and drop the reference
|
* on the mark because it was in the idr.
|
*/
|
static void inotify_remove_from_idr(struct fsnotify_group *group,
|
struct inotify_inode_mark *i_mark)
|
{
|
struct idr *idr = &group->inotify_data.idr;
|
spinlock_t *idr_lock = &group->inotify_data.idr_lock;
|
struct inotify_inode_mark *found_i_mark = NULL;
|
int wd;
|
|
spin_lock(idr_lock);
|
wd = i_mark->wd;
|
|
/*
|
* does this i_mark think it is in the idr? we shouldn't get called
|
* if it wasn't....
|
*/
|
if (wd == -1) {
|
WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p\n",
|
__func__, i_mark, i_mark->wd, i_mark->fsn_mark.group);
|
goto out;
|
}
|
|
/* Lets look in the idr to see if we find it */
|
found_i_mark = inotify_idr_find_locked(group, wd);
|
if (unlikely(!found_i_mark)) {
|
WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p\n",
|
__func__, i_mark, i_mark->wd, i_mark->fsn_mark.group);
|
goto out;
|
}
|
|
/*
|
* We found an mark in the idr at the right wd, but it's
|
* not the mark we were told to remove. eparis seriously
|
* fucked up somewhere.
|
*/
|
if (unlikely(found_i_mark != i_mark)) {
|
WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p "
|
"found_i_mark=%p found_i_mark->wd=%d "
|
"found_i_mark->group=%p\n", __func__, i_mark,
|
i_mark->wd, i_mark->fsn_mark.group, found_i_mark,
|
found_i_mark->wd, found_i_mark->fsn_mark.group);
|
goto out;
|
}
|
|
/*
|
* One ref for being in the idr
|
* one ref grabbed by inotify_idr_find
|
*/
|
if (unlikely(refcount_read(&i_mark->fsn_mark.refcnt) < 2)) {
|
printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p\n",
|
__func__, i_mark, i_mark->wd, i_mark->fsn_mark.group);
|
/* we can't really recover with bad ref cnting.. */
|
BUG();
|
}
|
|
idr_remove(idr, wd);
|
/* Removed from the idr, drop that ref. */
|
fsnotify_put_mark(&i_mark->fsn_mark);
|
out:
|
i_mark->wd = -1;
|
spin_unlock(idr_lock);
|
/* match the ref taken by inotify_idr_find_locked() */
|
if (found_i_mark)
|
fsnotify_put_mark(&found_i_mark->fsn_mark);
|
}
|
|
/*
|
* Send IN_IGNORED for this wd, remove this wd from the idr.
|
*/
|
void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
|
struct fsnotify_group *group)
|
{
|
struct inotify_inode_mark *i_mark;
|
|
/* Queue ignore event for the watch */
|
inotify_handle_inode_event(fsn_mark, FS_IN_IGNORED, NULL, NULL, NULL,
|
0);
|
|
i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
|
/* remove this mark from the idr */
|
inotify_remove_from_idr(group, i_mark);
|
|
dec_inotify_watches(group->inotify_data.ucounts);
|
}
|
|
static int inotify_update_existing_watch(struct fsnotify_group *group,
|
struct inode *inode,
|
u32 arg)
|
{
|
struct fsnotify_mark *fsn_mark;
|
struct inotify_inode_mark *i_mark;
|
__u32 old_mask, new_mask;
|
__u32 mask;
|
int add = (arg & IN_MASK_ADD);
|
int create = (arg & IN_MASK_CREATE);
|
int ret;
|
|
mask = inotify_arg_to_mask(inode, arg);
|
|
fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
|
if (!fsn_mark)
|
return -ENOENT;
|
else if (create) {
|
ret = -EEXIST;
|
goto out;
|
}
|
|
i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
|
|
spin_lock(&fsn_mark->lock);
|
old_mask = fsn_mark->mask;
|
if (add)
|
fsn_mark->mask |= mask;
|
else
|
fsn_mark->mask = mask;
|
new_mask = fsn_mark->mask;
|
spin_unlock(&fsn_mark->lock);
|
|
if (old_mask != new_mask) {
|
/* more bits in old than in new? */
|
int dropped = (old_mask & ~new_mask);
|
/* more bits in this fsn_mark than the inode's mask? */
|
int do_inode = (new_mask & ~inode->i_fsnotify_mask);
|
|
/* update the inode with this new fsn_mark */
|
if (dropped || do_inode)
|
fsnotify_recalc_mask(inode->i_fsnotify_marks);
|
|
}
|
|
/* return the wd */
|
ret = i_mark->wd;
|
|
out:
|
/* match the get from fsnotify_find_mark() */
|
fsnotify_put_mark(fsn_mark);
|
|
return ret;
|
}
|
|
static int inotify_new_watch(struct fsnotify_group *group,
|
struct inode *inode,
|
u32 arg)
|
{
|
struct inotify_inode_mark *tmp_i_mark;
|
__u32 mask;
|
int ret;
|
struct idr *idr = &group->inotify_data.idr;
|
spinlock_t *idr_lock = &group->inotify_data.idr_lock;
|
|
mask = inotify_arg_to_mask(inode, arg);
|
|
tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
|
if (unlikely(!tmp_i_mark))
|
return -ENOMEM;
|
|
fsnotify_init_mark(&tmp_i_mark->fsn_mark, group);
|
tmp_i_mark->fsn_mark.mask = mask;
|
tmp_i_mark->wd = -1;
|
|
ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
|
if (ret)
|
goto out_err;
|
|
/* increment the number of watches the user has */
|
if (!inc_inotify_watches(group->inotify_data.ucounts)) {
|
inotify_remove_from_idr(group, tmp_i_mark);
|
ret = -ENOSPC;
|
goto out_err;
|
}
|
|
/* we are on the idr, now get on the inode */
|
ret = fsnotify_add_inode_mark_locked(&tmp_i_mark->fsn_mark, inode, 0);
|
if (ret) {
|
/* we failed to get on the inode, get off the idr */
|
inotify_remove_from_idr(group, tmp_i_mark);
|
goto out_err;
|
}
|
|
|
/* return the watch descriptor for this new mark */
|
ret = tmp_i_mark->wd;
|
|
out_err:
|
/* match the ref from fsnotify_init_mark() */
|
fsnotify_put_mark(&tmp_i_mark->fsn_mark);
|
|
return ret;
|
}
|
|
static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg)
|
{
|
int ret = 0;
|
|
mutex_lock(&group->mark_mutex);
|
/* try to update and existing watch with the new arg */
|
ret = inotify_update_existing_watch(group, inode, arg);
|
/* no mark present, try to add a new one */
|
if (ret == -ENOENT)
|
ret = inotify_new_watch(group, inode, arg);
|
mutex_unlock(&group->mark_mutex);
|
|
return ret;
|
}
|
|
static struct fsnotify_group *inotify_new_group(unsigned int max_events)
|
{
|
struct fsnotify_group *group;
|
struct inotify_event_info *oevent;
|
|
group = fsnotify_alloc_group(&inotify_fsnotify_ops);
|
if (IS_ERR(group))
|
return group;
|
|
oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL);
|
if (unlikely(!oevent)) {
|
fsnotify_destroy_group(group);
|
return ERR_PTR(-ENOMEM);
|
}
|
group->overflow_event = &oevent->fse;
|
fsnotify_init_event(group->overflow_event, 0);
|
oevent->mask = FS_Q_OVERFLOW;
|
oevent->wd = -1;
|
oevent->sync_cookie = 0;
|
oevent->name_len = 0;
|
|
group->max_events = max_events;
|
group->memcg = get_mem_cgroup_from_mm(current->mm);
|
|
spin_lock_init(&group->inotify_data.idr_lock);
|
idr_init(&group->inotify_data.idr);
|
group->inotify_data.ucounts = inc_ucount(current_user_ns(),
|
current_euid(),
|
UCOUNT_INOTIFY_INSTANCES);
|
|
if (!group->inotify_data.ucounts) {
|
fsnotify_destroy_group(group);
|
return ERR_PTR(-EMFILE);
|
}
|
|
return group;
|
}
|
|
|
/* inotify syscalls */
|
static int do_inotify_init(int flags)
|
{
|
struct fsnotify_group *group;
|
int ret;
|
|
/* Check the IN_* constants for consistency. */
|
BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
|
BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
|
|
if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
|
return -EINVAL;
|
|
/* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */
|
group = inotify_new_group(inotify_max_queued_events);
|
if (IS_ERR(group))
|
return PTR_ERR(group);
|
|
ret = anon_inode_getfd("inotify", &inotify_fops, group,
|
O_RDONLY | flags);
|
if (ret < 0)
|
fsnotify_destroy_group(group);
|
|
return ret;
|
}
|
|
SYSCALL_DEFINE1(inotify_init1, int, flags)
|
{
|
return do_inotify_init(flags);
|
}
|
|
SYSCALL_DEFINE0(inotify_init)
|
{
|
return do_inotify_init(0);
|
}
|
|
SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
|
u32, mask)
|
{
|
struct fsnotify_group *group;
|
struct inode *inode;
|
struct path path;
|
struct path alteredpath;
|
struct path *canonical_path = &path;
|
struct fd f;
|
int ret;
|
unsigned flags = 0;
|
|
/*
|
* We share a lot of code with fs/dnotify. We also share
|
* the bit layout between inotify's IN_* and the fsnotify
|
* FS_*. This check ensures that only the inotify IN_*
|
* bits get passed in and set in watches/events.
|
*/
|
if (unlikely(mask & ~ALL_INOTIFY_BITS))
|
return -EINVAL;
|
/*
|
* Require at least one valid bit set in the mask.
|
* Without _something_ set, we would have no events to
|
* watch for.
|
*/
|
if (unlikely(!(mask & ALL_INOTIFY_BITS)))
|
return -EINVAL;
|
|
f = fdget(fd);
|
if (unlikely(!f.file))
|
return -EBADF;
|
|
/* IN_MASK_ADD and IN_MASK_CREATE don't make sense together */
|
if (unlikely((mask & IN_MASK_ADD) && (mask & IN_MASK_CREATE))) {
|
ret = -EINVAL;
|
goto fput_and_out;
|
}
|
|
/* verify that this is indeed an inotify instance */
|
if (unlikely(f.file->f_op != &inotify_fops)) {
|
ret = -EINVAL;
|
goto fput_and_out;
|
}
|
|
if (!(mask & IN_DONT_FOLLOW))
|
flags |= LOOKUP_FOLLOW;
|
if (mask & IN_ONLYDIR)
|
flags |= LOOKUP_DIRECTORY;
|
|
ret = inotify_find_inode(pathname, &path, flags,
|
(mask & IN_ALL_EVENTS));
|
if (ret)
|
goto fput_and_out;
|
|
/* support stacked filesystems */
|
if (path.dentry && path.dentry->d_op) {
|
if (path.dentry->d_op->d_canonical_path) {
|
path.dentry->d_op->d_canonical_path(&path,
|
&alteredpath);
|
canonical_path = &alteredpath;
|
path_put(&path);
|
}
|
}
|
|
/* inode held in place by reference to path; group by fget on fd */
|
inode = canonical_path->dentry->d_inode;
|
group = f.file->private_data;
|
|
/* create/update an inode mark */
|
ret = inotify_update_watch(group, inode, mask);
|
path_put(canonical_path);
|
fput_and_out:
|
fdput(f);
|
return ret;
|
}
|
|
SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
|
{
|
struct fsnotify_group *group;
|
struct inotify_inode_mark *i_mark;
|
struct fd f;
|
int ret = -EINVAL;
|
|
f = fdget(fd);
|
if (unlikely(!f.file))
|
return -EBADF;
|
|
/* verify that this is indeed an inotify instance */
|
if (unlikely(f.file->f_op != &inotify_fops))
|
goto out;
|
|
group = f.file->private_data;
|
|
i_mark = inotify_idr_find(group, wd);
|
if (unlikely(!i_mark))
|
goto out;
|
|
ret = 0;
|
|
fsnotify_destroy_mark(&i_mark->fsn_mark, group);
|
|
/* match ref taken by inotify_idr_find */
|
fsnotify_put_mark(&i_mark->fsn_mark);
|
|
out:
|
fdput(f);
|
return ret;
|
}
|
|
/*
|
* inotify_user_setup - Our initialization function. Note that we cannot return
|
* error because we have compiled-in VFS hooks. So an (unlikely) failure here
|
* must result in panic().
|
*/
|
static int __init inotify_user_setup(void)
|
{
|
BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
|
BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
|
BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
|
BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
|
BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
|
BUILD_BUG_ON(IN_OPEN != FS_OPEN);
|
BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
|
BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
|
BUILD_BUG_ON(IN_CREATE != FS_CREATE);
|
BUILD_BUG_ON(IN_DELETE != FS_DELETE);
|
BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
|
BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
|
BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
|
BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
|
BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
|
BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK);
|
BUILD_BUG_ON(IN_ISDIR != FS_ISDIR);
|
BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
|
|
BUILD_BUG_ON(HWEIGHT32(ALL_INOTIFY_BITS) != 22);
|
|
inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark,
|
SLAB_PANIC|SLAB_ACCOUNT);
|
|
inotify_max_queued_events = 16384;
|
init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES] = 128;
|
init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES] = 8192;
|
|
return 0;
|
}
|
fs_initcall(inotify_user_setup);
|
