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 <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
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 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
/*
* 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 @@
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 @@
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 @@
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 @@
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 @@
{
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 @@
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 @@
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 */