Btrfs: Add some conditional schedules near the alloc_mutex

This helps prevent stalls, especially while the snapshot cleaner is
running hard

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index c51cd11de206..72fa28236e5d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -937,6 +937,7 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         level = btrfs_header_level(buf);
         nritems = btrfs_header_nritems(buf);
         for (i = 0; i < nritems; i++) {
+                cond_resched();
                 if (level == 0) {
                         u64 disk_bytenr;
                         btrfs_item_key_to_cpu(buf, &key, i);
@@ -2189,6 +2190,7 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
 
         for (i = 0; i < nritems; i++) {
                 u64 disk_bytenr;
+                cond_resched();
 
                 btrfs_item_key_to_cpu(leaf, &key, i);
                 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)