From: Chris Mason <chris.mason@oracle.com>
Date: Mon, 15 Mar 2010 14:21:30 +0000 (-0400)
Subject: Btrfs: don't look at bio flags after submit_bio
X-Git-Tag: v2.6.34-rc4~3^2~25
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5ff7ba3a797a8ffd5299b8477df2dca3c3ebd34e;p=platform%2Fupstream%2Fkernel-adaptation-pc.git

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>
---

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 4053fc4..9df8e3f 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);