Btrfs: fix deadlock in run_delalloc_nocow

@cur_offset is not set back to what it should be (@cow_start) if
btrfs_next_leaf() returns something wrong, and the range [cow_start,
cur_offset) remains locked forever.

cc: <[email protected]>
Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c5f31817778bc1fe9dc5027153de3bfcd2cc759a..a68a4acd16e51aac6e3633f7753ee66884b86069 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1334,8 +1334,11 @@ next_slot:
                leaf = path->nodes[0];
                if (path->slots[0] >= btrfs_header_nritems(leaf)) {
                        ret = btrfs_next_leaf(root, path);
-                       if (ret < 0)
+                       if (ret < 0) {
+                               if (cow_start != (u64)-1)
+                                       cur_offset = cow_start;
                                goto error;
+                       }
                        if (ret > 0)
                                break;
                        leaf = path->nodes[0];