Btrfs: do not abort transaction in prealloc case

During disk balance, we prealloc new file extent for file data relocation,
but we may fail in 'no available space' case, and it leads to flipping btrfs
into readonly.

It is not necessary to bail out and abort transaction since we do have several
ways to rescue ourselves from ENOSPC case.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d1ebd2a06116..67bd12a52369 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5748,7 +5748,11 @@ loop:
                                 ret = do_chunk_alloc(trans, root, num_bytes +
                                                      2 * 1024 * 1024, data,
                                                      CHUNK_ALLOC_LIMITED);
-                                if (ret < 0) {
+                                /*
+                                 * Do not bail out on ENOSPC since we
+                                 * can do more things.
+                                 */
+                                if (ret < 0 && ret != -ENOSPC) {
                                         btrfs_abort_transaction(trans,
                                                                 root, ret);
                                         goto out;