Btrfs: don't look at bio flags after submit_bio

After callling submit_bio, the bio can be freed at any time.  The
btrfs submission thread helper was checking the bio flags too late,
which might not give the correct answer.

When CONFIG_DEBUG_PAGE_ALLOC is turned on, it can lead to oopsen.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 4053fc44d2cf..9df8e3f1ccab 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -256,13 +256,13 @@ loop_lock:
                         wake_up(&fs_info->async_submit_wait);
 
                 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
-                submit_bio(cur->bi_rw, cur);
-                num_run++;
-                batch_run++;
 
                 if (bio_rw_flagged(cur, BIO_RW_SYNCIO))
                         num_sync_run++;
 
+                submit_bio(cur->bi_rw, cur);
+                num_run++;
+                batch_run++;
                 if (need_resched()) {
                         if (num_sync_run) {
                                 blk_run_backing_dev(bdi, NULL);