Btrfs: Only do async bio submission for pdflush

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

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9e41ea93ebce..76ee7a4ae00c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -381,6 +381,13 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 {
         struct async_submit_bio *async;
 
+        /*
+         * inline writerback should stay inline, only hop to the async
+         * queue if we're pdflush
+         */
+        if (!current_is_pdflush())
+                return submit_bio_hook(inode, rw, bio, mirror_num);
+
         async = kmalloc(sizeof(*async), GFP_NOFS);
         if (!async)
                 return -ENOMEM;