Instead of taking 1. mark->lock 2. group->mark_lock 3. inode->lock we now use another order in fsnotify_add_mark(): 1. inode->lock 2. mark->lock and assume that the callers took the group->mark_lock already. By taking the mark_lock first, we can protect modification of the groups mark list without the need of an extra lock like the group->mutex. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx> --- fs/notify/mark.c | 38 +++++--------------------------------- 1 files changed, 5 insertions(+), 33 deletions(-) diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 28b64eb..a677af0 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -213,20 +213,9 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, /* * LOCKING ORDER!!!! - * mark->lock - * group->mark_lock * inode->i_lock + * mark->lock */ - spin_lock(&mark->lock); - spin_lock(&group->mark_lock); - - mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE; - mark->group = group; - list_add(&mark->g_list, &group->marks_list); - fsnotify_get_mark(mark); /* for i_list and g_list */ - atomic_inc(&group->num_marks); - - ret = 0; if (inode) ret = fsnotify_add_inode_mark(mark, group, inode, allow_dups); else if (mnt) @@ -234,34 +223,17 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, else BUG(); if (ret) - goto err; - - spin_unlock(&group->mark_lock); + return ret; - /* this will pin the object if appropriate */ - fsnotify_set_mark_mask_locked(mark, mark->mask); + fsnotify_get_mark(mark); /* for i_list and g_list */ - spin_unlock(&mark->lock); + list_add(&mark->g_list, &group->marks_list); + atomic_inc(&group->num_marks); if (inode) __fsnotify_update_child_dentry_flags(inode); return 0; -err: - mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; - list_del_init(&mark->g_list); - mark->group = NULL; - atomic_dec(&group->num_marks); - - spin_unlock(&group->mark_lock); - spin_unlock(&mark->lock); - - spin_lock(&destroy_lock); - list_add(&mark->destroy_list, &destroy_list); - spin_unlock(&destroy_lock); - wake_up(&destroy_waitq); - - return ret; } /* -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
