Commit fc013a58 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  inotify: use GFP_NOFS under potential memory pressure
  fsnotify: fix inotify tail drop check with path entries
  inotify: check filename before dropping repeat events
  fsnotify: use def_bool in kconfig instead of letting the user choose
  inotify: fix error paths in inotify_update_watch
  inotify: do not leak inode marks in inotify_add_watch
  inotify: drop user watch count when a watch is removed
parents 3a542974 f44aebcc

fs/notify/Kconfig

+1 −11
Original line number Diff line number Diff line 
config FSNOTIFY

	bool "Filesystem notification backend"

	default y

	---help---

	   fsnotify is a backend for filesystem notification.  fsnotify does

	   not provide any userspace interface but does provide the basis

	   needed for other notification schemes such as dnotify, inotify,

	   and fanotify.



	   Say Y here to enable fsnotify suport.



	   If unsure, say Y.

	def_bool n



source "fs/notify/dnotify/Kconfig"

source "fs/notify/inotify/Kconfig"

fs/notify/dnotify/Kconfig

+1 −1
Original line number Diff line number Diff line 
config DNOTIFY

	bool "Dnotify support"

	depends on FSNOTIFY

	select FSNOTIFY

	default y

	help

	  Dnotify is a directory-based per-fd file change notification system

fs/notify/fsnotify.c

+3 −1
Original line number Diff line number Diff line
@@ -159,7 +159,9 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const 
			if (!group->ops->should_send_event(group, to_tell, mask))

				continue;

			if (!event) {

				event = fsnotify_create_event(to_tell, mask, data, data_is, file_name, cookie);

				event = fsnotify_create_event(to_tell, mask, data,

							      data_is, file_name, cookie,

							      GFP_KERNEL);

				/* shit, we OOM'd and now we can't tell, maybe

				 * someday someone else will want to do something

				 * here */

fs/notify/inotify/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ config INOTIFY 


config INOTIFY_USER

	bool "Inotify support for userspace"

	depends on FSNOTIFY

	select FSNOTIFY

	default y

	---help---

	  Say Y here to enable inotify support for userspace, including the

fs/notify/inotify/inotify_user.c

+71 −38
Original line number Diff line number Diff line
@@ -57,7 +57,6 @@ int inotify_max_user_watches __read_mostly; 


static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;

struct kmem_cache *event_priv_cachep __read_mostly;

static struct fsnotify_event *inotify_ignored_event;



/*

 * When inotify registers a new group it increments this and uses that
@@ -365,6 +364,17 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns 
	return error;

}



static void inotify_remove_from_idr(struct fsnotify_group *group,

				    struct inotify_inode_mark_entry *ientry)

{

	struct idr *idr;



	spin_lock(&group->inotify_data.idr_lock);

	idr = &group->inotify_data.idr;

	idr_remove(idr, ientry->wd);

	spin_unlock(&group->inotify_data.idr_lock);

	ientry->wd = -1;

}

/*

 * Send IN_IGNORED for this wd, remove this wd from the idr, and drop the

 * internal reference help on the mark because it is in the idr.
@@ -373,13 +383,19 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry, 
				    struct fsnotify_group *group)

{

	struct inotify_inode_mark_entry *ientry;

	struct fsnotify_event *ignored_event;

	struct inotify_event_private_data *event_priv;

	struct fsnotify_event_private_data *fsn_event_priv;

	struct idr *idr;



	ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL,

					      FSNOTIFY_EVENT_NONE, NULL, 0,

					      GFP_NOFS);

	if (!ignored_event)

		return;



	ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);



	event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);

	event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS);

	if (unlikely(!event_priv))

		goto skip_send_ignore;
@@ -388,7 +404,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry, 
	fsn_event_priv->group = group;

	event_priv->wd = ientry->wd;



	fsnotify_add_notify_event(group, inotify_ignored_event, fsn_event_priv);

	fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);



	/* did the private data get added? */

	if (list_empty(&fsn_event_priv->event_list))
@@ -396,14 +412,16 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry, 


skip_send_ignore:



	/* matches the reference taken when the event was created */

	fsnotify_put_event(ignored_event);



	/* remove this entry from the idr */

	spin_lock(&group->inotify_data.idr_lock);

	idr = &group->inotify_data.idr;

	idr_remove(idr, ientry->wd);

	spin_unlock(&group->inotify_data.idr_lock);

	inotify_remove_from_idr(group, ientry);



	/* removed from idr, drop that reference */

	fsnotify_put_mark(entry);



	atomic_dec(&group->inotify_data.user->inotify_watches);

}



/* ding dong the mark is dead */
@@ -418,6 +436,7 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod 
{

	struct fsnotify_mark_entry *entry = NULL;

	struct inotify_inode_mark_entry *ientry;

	struct inotify_inode_mark_entry *tmp_ientry;

	int ret = 0;

	int add = (arg & IN_MASK_ADD);

	__u32 mask;
@@ -428,54 +447,66 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod 
	if (unlikely(!mask))

		return -EINVAL;



	ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);

	if (unlikely(!ientry))

	tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);

	if (unlikely(!tmp_ientry))

		return -ENOMEM;

	/* we set the mask at the end after attaching it */

	fsnotify_init_mark(&ientry->fsn_entry, inotify_free_mark);

	ientry->wd = 0;

	fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);

	tmp_ientry->wd = -1;



find_entry:

	spin_lock(&inode->i_lock);

	entry = fsnotify_find_mark_entry(group, inode);

	spin_unlock(&inode->i_lock);

	if (entry) {

		kmem_cache_free(inotify_inode_mark_cachep, ientry);

		ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);

	} else {

		if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) {

		ret = -ENOSPC;

		if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)

			goto out_err;

		}



		ret = fsnotify_add_mark(&ientry->fsn_entry, group, inode);

		if (ret == -EEXIST)

			goto find_entry;

		else if (ret)

			goto out_err;



		entry = &ientry->fsn_entry;

retry:

		ret = -ENOMEM;

		if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))

			goto out_err;



		spin_lock(&group->inotify_data.idr_lock);

		/* if entry is added to the idr we keep the reference obtained

		 * through fsnotify_mark_add.  remember to drop this reference

		 * when entry is removed from idr */

		ret = idr_get_new_above(&group->inotify_data.idr, entry,

					++group->inotify_data.last_wd,

					&ientry->wd);

		ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,

					group->inotify_data.last_wd,

					&tmp_ientry->wd);

		spin_unlock(&group->inotify_data.idr_lock);

		if (ret) {

			if (ret == -EAGAIN)

				goto retry;

			goto out_err;

		}



		ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);

		if (ret) {

			inotify_remove_from_idr(group, tmp_ientry);

			if (ret == -EEXIST)

				goto find_entry;

			goto out_err;

		}



		/* tmp_ientry has been added to the inode, so we are all set up.

		 * now we just need to make sure tmp_ientry doesn't get freed and

		 * we need to set up entry and ientry so the generic code can

		 * do its thing. */

		ientry = tmp_ientry;

		entry = &ientry->fsn_entry;

		tmp_ientry = NULL;



		atomic_inc(&group->inotify_data.user->inotify_watches);



		/* update the idr hint */

		group->inotify_data.last_wd = ientry->wd;



		/* we put the mark on the idr, take a reference */

		fsnotify_get_mark(entry);

	}



	ret = ientry->wd;



	spin_lock(&entry->lock);



	old_mask = entry->mask;
@@ -506,14 +537,19 @@ retry: 
			fsnotify_recalc_group_mask(group);

	}



	return ientry->wd;

	/* this either matches fsnotify_find_mark_entry, or init_mark_entry

	 * depending on which path we took... */

	fsnotify_put_mark(entry);



out_err:

	/* see this isn't supposed to happen, just kill the watch */

	if (entry) {

		fsnotify_destroy_mark_by_entry(entry);

		fsnotify_put_mark(entry);

	/* could be an error, could be that we found an existing mark */

	if (tmp_ientry) {

		/* on the idr but didn't make it on the inode */

		if (tmp_ientry->wd != -1)

			inotify_remove_from_idr(group, tmp_ientry);

		kmem_cache_free(inotify_inode_mark_cachep, tmp_ientry);

	}



	return ret;

}
@@ -721,9 +757,6 @@ static int __init inotify_user_setup(void) 


	inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC);

	event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC);

	inotify_ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, FSNOTIFY_EVENT_NONE, NULL, 0);

	if (!inotify_ignored_event)

		panic("unable to allocate the inotify ignored event\n");



	inotify_max_queued_events = 16384;

	inotify_max_user_instances = 128;

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