From d5a335b845792d2a69ed1e244c0b233117b7db3c Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo Date: Tue, 14 Jun 2011 17:29:52 +0200 Subject: [PATCH] fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark() This patch introduces fsnotify_add_mark_locked() and fsnotify_remove_mark_locked() which are essentially the same as fsnotify_add_mark() and fsnotify_remove_mark() but assume that the caller has already taken the groups mark mutex. Signed-off-by: Lino Sanfilippo Signed-off-by: Eric Paris --- fs/notify/mark.c | 42 +++++++++++++++++++++++--------- include/linux/fsnotify_backend.h | 4 +++ 2 files changed, 34 insertions(+), 12 deletions(-) diff --git a/fs/notify/mark.c b/fs/notify/mark.c index b77c833c8d0a..f9dda0304a10 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -121,18 +121,18 @@ void fsnotify_put_mark(struct fsnotify_mark *mark) * The caller had better be holding a reference to this mark so we don't actually * do the final put under the mark->lock */ -void fsnotify_destroy_mark(struct fsnotify_mark *mark, - struct fsnotify_group *group) +void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, + struct fsnotify_group *group) { struct inode *inode = NULL; - mutex_lock(&group->mark_mutex); + BUG_ON(!mutex_is_locked(&group->mark_mutex)); + spin_lock(&mark->lock); /* something else already called this function on this mark */ if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) { spin_unlock(&mark->lock); - mutex_unlock(&group->mark_mutex); return; } @@ -149,6 +149,8 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, list_del_init(&mark->g_list); spin_unlock(&mark->lock); + + /* release lock temporarily */ mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); @@ -184,6 +186,16 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, */ atomic_dec(&group->num_marks); + + mutex_lock(&group->mark_mutex); +} + +void fsnotify_destroy_mark(struct fsnotify_mark *mark, + struct fsnotify_group *group) +{ + mutex_lock(&group->mark_mutex); + fsnotify_destroy_mark_locked(mark, group); + mutex_unlock(&group->mark_mutex); } void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask) @@ -208,14 +220,15 @@ void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mas * These marks may be used for the fsnotify backend to determine which * event types should be delivered to which group. */ -int fsnotify_add_mark(struct fsnotify_mark *mark, - struct fsnotify_group *group, struct inode *inode, - struct vfsmount *mnt, int allow_dups) +int fsnotify_add_mark_locked(struct fsnotify_mark *mark, + struct fsnotify_group *group, struct inode *inode, + struct vfsmount *mnt, int allow_dups) { int ret = 0; BUG_ON(inode && mnt); BUG_ON(!inode && !mnt); + BUG_ON(!mutex_is_locked(&group->mark_mutex)); /* * LOCKING ORDER!!!! @@ -223,8 +236,6 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, * mark->lock * inode->i_lock */ - mutex_lock(&group->mark_mutex); - spin_lock(&mark->lock); mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE; @@ -250,8 +261,6 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_set_mark_mask_locked(mark, mark->mask); spin_unlock(&mark->lock); - mutex_unlock(&group->mark_mutex); - if (inode) __fsnotify_update_child_dentry_flags(inode); @@ -264,7 +273,6 @@ err: atomic_dec(&group->num_marks); spin_unlock(&mark->lock); - mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); list_add(&mark->destroy_list, &destroy_list); @@ -274,6 +282,16 @@ err: return ret; } +int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group, + struct inode *inode, struct vfsmount *mnt, int allow_dups) +{ + int ret; + mutex_lock(&group->mark_mutex); + ret = fsnotify_add_mark_locked(mark, group, inode, mnt, allow_dups); + mutex_unlock(&group->mark_mutex); + return ret; +} + /* * clear any marks in a group in which mark->flags & flags is true */ diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 140b4b8a100b..26c06afa264e 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -408,9 +408,13 @@ extern void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask /* attach the mark to both the group and the inode */ extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group, struct inode *inode, struct vfsmount *mnt, int allow_dups); +extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct fsnotify_group *group, + struct inode *inode, struct vfsmount *mnt, int allow_dups); /* given a group and a mark, flag mark to be freed when all references are dropped */ extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, struct fsnotify_group *group); +extern void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, + struct fsnotify_group *group); /* run all the marks in a group, and clear all of the vfsmount marks */ extern void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group); /* run all the marks in a group, and clear all of the inode marks */