From 986ab09807ca9454c3f54aae4db7e1bb00daeed3 Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo Date: Tue, 14 Jun 2011 17:29:50 +0200 Subject: fsnotify: use a mutex instead of a spinlock to protect a groups mark list Replaces the groups mark_lock spinlock with a mutex. Using a mutex instead of a spinlock results in more flexibility (i.e it allows to sleep while the lock is held). Signed-off-by: Lino Sanfilippo Signed-off-by: Eric Paris diff --git a/fs/notify/group.c b/fs/notify/group.c index 354044c..1f73057 100644 --- a/fs/notify/group.c +++ b/fs/notify/group.c @@ -95,7 +95,7 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops) init_waitqueue_head(&group->notification_waitq); group->max_events = UINT_MAX; - spin_lock_init(&group->mark_lock); + mutex_init(&group->mark_mutex); INIT_LIST_HEAD(&group->marks_list); group->ops = ops; diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c index b13c00a..4e9071e 100644 --- a/fs/notify/inode_mark.c +++ b/fs/notify/inode_mark.c @@ -63,8 +63,8 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark) { struct inode *inode = mark->i.inode; + BUG_ON(!mutex_is_locked(&mark->group->mark_mutex)); assert_spin_locked(&mark->lock); - assert_spin_locked(&mark->group->mark_lock); spin_lock(&inode->i_lock); @@ -191,8 +191,8 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark, mark->flags |= FSNOTIFY_MARK_FLAG_INODE; + BUG_ON(!mutex_is_locked(&group->mark_mutex)); assert_spin_locked(&mark->lock); - assert_spin_locked(&group->mark_lock); spin_lock(&inode->i_lock); diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 32447dc..ab25b81 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -136,13 +136,13 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark) group = mark->group; spin_unlock(&mark->lock); - spin_lock(&group->mark_lock); + mutex_lock(&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); - spin_unlock(&group->mark_lock); + mutex_unlock(&group->mark_mutex); goto put_group; } @@ -159,7 +159,7 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark) list_del_init(&mark->g_list); spin_unlock(&mark->lock); - spin_unlock(&group->mark_lock); + mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); list_add(&mark->destroy_list, &destroy_list); @@ -232,11 +232,11 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, /* * LOCKING ORDER!!!! - * group->mark_lock + * group->mark_mutex * mark->lock * inode->i_lock */ - spin_lock(&group->mark_lock); + mutex_lock(&group->mark_mutex); spin_lock(&mark->lock); mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE; @@ -263,7 +263,7 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_set_mark_mask_locked(mark, mark->mask); spin_unlock(&mark->lock); - spin_unlock(&group->mark_lock); + mutex_unlock(&group->mark_mutex); if (inode) __fsnotify_update_child_dentry_flags(inode); @@ -277,7 +277,7 @@ err: atomic_dec(&group->num_marks); spin_unlock(&mark->lock); - spin_unlock(&group->mark_lock); + mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); list_add(&mark->destroy_list, &destroy_list); @@ -296,7 +296,7 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, struct fsnotify_mark *lmark, *mark; LIST_HEAD(free_list); - spin_lock(&group->mark_lock); + mutex_lock(&group->mark_mutex); list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) { if (mark->flags & flags) { list_add(&mark->free_g_list, &free_list); @@ -304,7 +304,7 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, fsnotify_get_mark(mark); } } - spin_unlock(&group->mark_lock); + mutex_unlock(&group->mark_mutex); list_for_each_entry_safe(mark, lmark, &free_list, free_g_list) { fsnotify_destroy_mark(mark); diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c index b7b4b0e..f26a348 100644 --- a/fs/notify/vfsmount_mark.c +++ b/fs/notify/vfsmount_mark.c @@ -88,8 +88,8 @@ void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark) { struct vfsmount *mnt = mark->m.mnt; + BUG_ON(!mutex_is_locked(&mark->group->mark_mutex)); assert_spin_locked(&mark->lock); - assert_spin_locked(&mark->group->mark_lock); spin_lock(&mnt->mnt_root->d_lock); @@ -151,8 +151,8 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark, mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT; + BUG_ON(!mutex_is_locked(&group->mark_mutex)); assert_spin_locked(&mark->lock); - assert_spin_locked(&group->mark_lock); spin_lock(&mnt->mnt_root->d_lock); diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index e76cef7..c584834 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -141,7 +141,7 @@ struct fsnotify_group { unsigned int priority; /* stores all fastpath marks assoc with this group so they can be cleaned on unregister */ - spinlock_t mark_lock; /* protect marks_list */ + struct mutex mark_mutex; /* protect marks_list */ atomic_t num_marks; /* 1 for each mark and 1 for not being * past the point of no return when freeing * a group */ -- cgit v0.10.2