[PATCH v10 12/16] Btrfs: fix deadlock of dedup work

[Liu Bo <bo.li.liu@oracle.com>]

Checking for dedup references needs to allocate memory so it cannot
be run within spin_lock, otherwise it will end up with heavy deadlock.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/extent-tree.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a8da7aa..4c1c342 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5720,7 +5720,6 @@ again:
 	dedup_hash = 0;
 
 	path->reada = 1;
-	path->leave_spinning = 1;
 
 	is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
 	BUG_ON(!is_data && refs_to_drop != 1);
@@ -5774,7 +5773,6 @@ again:
 				goto out;
 			}
 			btrfs_release_path(path);
-			path->leave_spinning = 1;
 
 			key.objectid = bytenr;
 			key.type = BTRFS_EXTENT_ITEM_KEY;
@@ -5942,6 +5940,7 @@ again:
 				dedup_hash = extent_data_ref_offset(root,
 								    path, iref);
 
+			WARN_ON_ONCE(path->leave_spinning);
 			ret = btrfs_free_dedup_extent(trans, root,
 						      dedup_hash, bytenr);
 			if (ret) {
-- 
1.8.1.4