diff options
author | Lino Sanfilippo <LinoSanfilippo@gmx.de> | 2013-07-08 22:59:44 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-09 17:33:20 (GMT) |
commit | 52f85729805b7a0ec5a7a70e2c814193929de2f0 (patch) | |
tree | cea36db4bfc807c0dfa357da02f5bb899df863a1 | |
parent | 5e9c070ca085439fbec9e9629dd6171ae325d4d8 (diff) | |
download | linux-52f85729805b7a0ec5a7a70e2c814193929de2f0.tar.xz |
dnotify: replace dnotify_mark_mutex with mark mutex of dnotify_group
There is no need to use a special mutex to protect against the
fcntl/close race (see dnotify.c for a description of this race).
Instead the dnotify_groups mark mutex can be used.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | fs/notify/dnotify/dnotify.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index 2bfe6dc..1fedd5f 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -31,7 +31,6 @@ int dir_notify_enable __read_mostly = 1; static struct kmem_cache *dnotify_struct_cache __read_mostly; static struct kmem_cache *dnotify_mark_cache __read_mostly; static struct fsnotify_group *dnotify_group __read_mostly; -static DEFINE_MUTEX(dnotify_mark_mutex); /* * dnotify will attach one of these to each inode (i_fsnotify_marks) which @@ -183,7 +182,7 @@ void dnotify_flush(struct file *filp, fl_owner_t id) return; dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark); - mutex_lock(&dnotify_mark_mutex); + mutex_lock(&dnotify_group->mark_mutex); spin_lock(&fsn_mark->lock); prev = &dn_mark->dn; @@ -199,11 +198,12 @@ void dnotify_flush(struct file *filp, fl_owner_t id) spin_unlock(&fsn_mark->lock); - /* nothing else could have found us thanks to the dnotify_mark_mutex */ + /* nothing else could have found us thanks to the dnotify_groups + mark_mutex */ if (dn_mark->dn == NULL) - fsnotify_destroy_mark(fsn_mark, dnotify_group); + fsnotify_destroy_mark_locked(fsn_mark, dnotify_group); - mutex_unlock(&dnotify_mark_mutex); + mutex_unlock(&dnotify_group->mark_mutex); fsnotify_put_mark(fsn_mark); } @@ -326,7 +326,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) new_dn_mark->dn = NULL; /* this is needed to prevent the fcntl/close race described below */ - mutex_lock(&dnotify_mark_mutex); + mutex_lock(&dnotify_group->mark_mutex); /* add the new_fsn_mark or find an old one. */ fsn_mark = fsnotify_find_inode_mark(dnotify_group, inode); @@ -334,7 +334,8 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark); spin_lock(&fsn_mark->lock); } else { - fsnotify_add_mark(new_fsn_mark, dnotify_group, inode, NULL, 0); + fsnotify_add_mark_locked(new_fsn_mark, dnotify_group, inode, + NULL, 0); spin_lock(&new_fsn_mark->lock); fsn_mark = new_fsn_mark; dn_mark = new_dn_mark; @@ -348,9 +349,9 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) /* if (f != filp) means that we lost a race and another task/thread * actually closed the fd we are still playing with before we grabbed - * the dnotify_mark_mutex and fsn_mark->lock. Since closing the fd is the - * only time we clean up the marks we need to get our mark off - * the list. */ + * the dnotify_groups mark_mutex and fsn_mark->lock. Since closing the + * fd is the only time we clean up the marks we need to get our mark + * off the list. */ if (f != filp) { /* if we added ourselves, shoot ourselves, it's possible that * the flush actually did shoot this fsn_mark. That's fine too @@ -385,9 +386,9 @@ out: spin_unlock(&fsn_mark->lock); if (destroy) - fsnotify_destroy_mark(fsn_mark, dnotify_group); + fsnotify_destroy_mark_locked(fsn_mark, dnotify_group); - mutex_unlock(&dnotify_mark_mutex); + mutex_unlock(&dnotify_group->mark_mutex); fsnotify_put_mark(fsn_mark); out_err: if (new_fsn_mark) |