Btrfs: fix a deadlock in aborting transaction due to ENOSPC
When committing a transaction, we may bail out of running delayed refs
due to ENOSPC, and then abort the current transaction to flip into readonly.
But we'll hit a deadlock on ref head's lock since we forget to release
its lock and other cleanup stuff.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0bcb954..f8a358a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2297,6 +2297,9 @@
kfree(extent_op);
if (ret) {
+ list_del_init(&locked_ref->cluster);
+ mutex_unlock(&locked_ref->mutex);
+
printk(KERN_DEBUG "btrfs: run_delayed_extent_op returned %d\n", ret);
spin_lock(&delayed_refs->lock);
return ret;
@@ -2339,6 +2342,10 @@
count++;
if (ret) {
+ if (locked_ref) {
+ list_del_init(&locked_ref->cluster);
+ mutex_unlock(&locked_ref->mutex);
+ }
printk(KERN_DEBUG "btrfs: run_one_delayed_ref returned %d\n", ret);
spin_lock(&delayed_refs->lock);
return ret;