Btrfs: split the global ordered extents mutex
When we create a snapshot, we just need wait the ordered extents in
the source fs/file root, but because we use the global mutex to protect
this ordered extents list of the source fs/file root to avoid accessing
a empty list, if someone got the mutex to access the ordered extents list
of the other fs/file root, we had to wait.
This patch splits the above global mutex, now every fs/file root has
its own mutex to protect its own list.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index a75eaa2..a94b05f 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -595,7 +595,7 @@
* wait for all the ordered extents in a root. This is done when balancing
* space between drives.
*/
-static int __btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
+int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
{
struct list_head splice, works;
struct btrfs_ordered_extent *ordered, *next;
@@ -604,6 +604,7 @@
INIT_LIST_HEAD(&splice);
INIT_LIST_HEAD(&works);
+ mutex_lock(&root->ordered_extent_mutex);
spin_lock(&root->ordered_extent_lock);
list_splice_init(&root->ordered_extents, &splice);
while (!list_empty(&splice) && nr) {
@@ -635,17 +636,7 @@
btrfs_put_ordered_extent(ordered);
cond_resched();
}
-
- return count;
-}
-
-int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
-{
- int count;
-
- mutex_lock(&root->fs_info->ordered_operations_mutex);
- count = __btrfs_wait_ordered_extents(root, nr);
- mutex_unlock(&root->fs_info->ordered_operations_mutex);
+ mutex_unlock(&root->ordered_extent_mutex);
return count;
}
@@ -670,7 +661,7 @@
&fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
- done = __btrfs_wait_ordered_extents(root, nr);
+ done = btrfs_wait_ordered_extents(root, nr);
btrfs_put_fs_root(root);
spin_lock(&fs_info->ordered_root_lock);