fs: make fsync_buffers_list() plug

It used WRITE_SYNC_PLUG before and potentially submits a batch
of IO, so lets enable plugging for this case.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/fs/buffer.c b/fs/buffer.c
index 42534f6..2e6b1a3 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -743,8 +743,10 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
        struct list_head tmp;
        struct address_space *mapping;
        int err = 0, err2;
+       struct blk_plug plug;
 
        INIT_LIST_HEAD(&tmp);
+       blk_start_plug(&plug);
 
        spin_lock(lock);
        while (!list_empty(list)) {
@@ -781,6 +783,10 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
                }
        }
 
+       spin_unlock(lock);
+       blk_finish_plug(&plug);
+       spin_lock(lock);
+
        while (!list_empty(&tmp)) {
                bh = BH_ENTRY(tmp.prev);
                get_bh(bh);