[GIT PULL] one writeback regression fix for .36

[Jens Axboe <jaxboe@fusionio.com>]

Hi Linus,

The recent patch series from Jan introduced a WARN_ON() regression.
The real fix for this is adding a super_operations->get_bdi(), which
we'll do for 2.6.37.

Please pull.

are available in the git repository at:
  git://git.kernel.dk/linux-2.6-block.git for-linus

Christoph Hellwig (1):
      writeback: always use sb->s_bdi for writeback purposes

 fs/fs-writeback.c |   19 ++++---------------
 1 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5581122..ab38fef 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -72,22 +72,11 @@ int writeback_in_progress(struct backing_dev_info *bdi)
 static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
-	struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
 
-	/*
-	 * For inodes on standard filesystems, we use superblock's bdi. For
-	 * inodes on virtual filesystems, we want to use inode mapping's bdi
-	 * because they can possibly point to something useful (think about
-	 * block_dev filesystem).
-	 */
-	if (sb->s_bdi && sb->s_bdi != &noop_backing_dev_info) {
-		/* Some device inodes could play dirty tricks. Catch them... */
-		WARN(bdi != sb->s_bdi && bdi_cap_writeback_dirty(bdi),
-			"Dirtiable inode bdi %s != sb bdi %s\n",
-			bdi->name, sb->s_bdi->name);
-		return sb->s_bdi;
-	}
-	return bdi;
+	if (strcmp(sb->s_type->name, "bdev") == 0)
+		return inode->i_mapping->backing_dev_info;
+
+	return sb->s_bdi;
 }
 
 static void bdi_queue_work(struct backing_dev_info *bdi,

-- 
Jens Axboe