[RFC][PATCH 15/16] writeback: clean-up the warning about non-registered bdi

[Artem Bityutskiy <dedekind1@gmail.com>]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

In '__mark_inode_dirty()', when the corresponding bdi was not properly
registered, we print a warning. But the corresponding code is a bit
untidy, it used if and 'WARN_ON(1)' and printk.

This patch turns it into one multi-line WARN() statement which looks
tidier and also uses 'unlikely()' for the condition which might matter
a tiny bit for this hot-path function.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/fs-writeback.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 559092d..83662fb 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -981,12 +981,9 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 			struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
 			struct backing_dev_info *bdi = wb->bdi;
 
-			if (bdi_cap_writeback_dirty(bdi) &&
-			    !test_bit(BDI_registered, &bdi->state)) {
-				WARN_ON(1);
-				printk(KERN_ERR "bdi-%s not registered\n",
-								bdi->name);
-			}
+			WARN(bdi_cap_writeback_dirty(bdi) &&
+			     !test_bit(BDI_registered, &bdi->state),
+			     "bdi-%s not registered\n", bdi->name);
 
 			inode->dirtied_when = jiffies;
 			list_move(&inode->i_list, &wb->b_dirty);
-- 
1.7.1.1