Commit 3ca10067 authored by Amy Griffis's avatar Amy Griffis Committed by Al Viro
Browse files

[PATCH] inotify (4/5): allow watch removal from event handler 



Allow callers to remove watches from their event handler via
inotify_remove_watch_locked().  This functionality can be used to
achieve IN_ONESHOT-like functionality for a subset of events in the
mask.

Signed-off-by: default avatarAmy Griffis <amy.griffis@hp.com>
Acked-by: default avatarRobert Love <rml@novell.com>
Acked-by: default avatarJohn McCutchan <john@johnmccutchan.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a9dc971d

fs/inotify.c

+14 −9
Original line number Diff line number Diff line
@@ -207,7 +207,7 @@ static struct inotify_watch *inode_find_handle(struct inode *inode, 
}



/*

 * remove_watch_no_event - remove_watch() without the IN_IGNORED event.

 * remove_watch_no_event - remove watch without the IN_IGNORED event.

 *

 * Callers must hold both inode->inotify_mutex and ih->mutex.

 */
@@ -223,17 +223,22 @@ static void remove_watch_no_event(struct inotify_watch *watch, 
	idr_remove(&ih->idr, watch->wd);

}



/*

 * remove_watch - Remove a watch from both the handle and the inode.  Sends

 * the IN_IGNORED event signifying that the inode is no longer watched.

/**

 * inotify_remove_watch_locked - Remove a watch from both the handle and the

 * inode.  Sends the IN_IGNORED event signifying that the inode is no longer

 * watched.  May be invoked from a caller's event handler.

 * @ih: inotify handle associated with watch

 * @watch: watch to remove

 *

 * Callers must hold both inode->inotify_mutex and ih->mutex.

 */

static void remove_watch(struct inotify_watch *watch, struct inotify_handle *ih)

void inotify_remove_watch_locked(struct inotify_handle *ih,

				 struct inotify_watch *watch)

{

	remove_watch_no_event(watch, ih);

	ih->in_ops->handle_event(watch, watch->wd, IN_IGNORED, 0, NULL, NULL);

}

EXPORT_SYMBOL_GPL(inotify_remove_watch_locked);



/* Kernel API for producing events */
@@ -378,7 +383,7 @@ void inotify_unmount_inodes(struct list_head *list) 


		need_iput_tmp = need_iput;

		need_iput = NULL;

		/* In case the remove_watch() drops a reference. */

		/* In case inotify_remove_watch_locked() drops a reference. */

		if (inode != need_iput_tmp)

			__iget(inode);

		else
@@ -411,7 +416,7 @@ void inotify_unmount_inodes(struct list_head *list) 
			mutex_lock(&ih->mutex);

			ih->in_ops->handle_event(watch, watch->wd, IN_UNMOUNT, 0,

						 NULL, NULL);

			remove_watch(watch, ih);

			inotify_remove_watch_locked(ih, watch);

			mutex_unlock(&ih->mutex);

		}

		mutex_unlock(&inode->inotify_mutex);
@@ -434,7 +439,7 @@ void inotify_inode_is_dead(struct inode *inode) 
	list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {

		struct inotify_handle *ih = watch->ih;

		mutex_lock(&ih->mutex);

		remove_watch(watch, ih);

		inotify_remove_watch_locked(ih, watch);

		mutex_unlock(&ih->mutex);

	}

	mutex_unlock(&inode->inotify_mutex);
@@ -687,7 +692,7 @@ int inotify_rm_wd(struct inotify_handle *ih, u32 wd) 


	/* make sure that we did not race */

	if (likely(idr_find(&ih->idr, wd) == watch))

		remove_watch(watch, ih);

		inotify_remove_watch_locked(ih, watch);



	mutex_unlock(&ih->mutex);

	mutex_unlock(&inode->inotify_mutex);

include/linux/inotify.h

+7 −0
Original line number Diff line number Diff line
@@ -122,6 +122,8 @@ extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *, 
			       struct inode *, __u32);

extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);

extern int inotify_rm_wd(struct inotify_handle *, __u32);

extern void inotify_remove_watch_locked(struct inotify_handle *,

					struct inotify_watch *);

extern void get_inotify_watch(struct inotify_watch *);

extern void put_inotify_watch(struct inotify_watch *);
@@ -205,6 +207,11 @@ static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd) 
	return -EOPNOTSUPP;

}



static inline void inotify_remove_watch_locked(struct inotify_handle *ih,

					       struct inotify_watch *watch)

{

}



static inline void get_inotify_watch(struct inotify_watch *watch)

{

}

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