[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: Amy Griffis <amy.griffis@hp.com>
Acked-by: Robert Love <rml@novell.com>
Acked-by: John McCutchan <john@johnmccutchan.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Amy Griffis 2006-06-01 13:11:05 -07:00 committed by Al Viro
parent a9dc971d3f
commit 3ca10067f7
2 changed files with 21 additions and 9 deletions

View File

@ -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);

View File

@ -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)
{
}