xfs: split xfs_sync_inodes

xfs_sync_inodes is used to write back either file data or inode metadata.
In general we always do these separately, except for one fishy case in
xfs_fs_put_super that does both.  So separate xfs_sync_inodes into
separate xfs_sync_data and xfs_sync_attr functions.  In xfs_fs_put_super
we first call the data sync and then the attr sync as that was the previous
order.  The moved log force in that path doesn't make a difference because
we will force the log again as part of the real unmount process.

The filesystem readonly checks are not performed by the new function but
instead moved into the callers, given that most callers alredy have it
further up in the stack.  Also add debug checks that we do not pass in
incorrect flags in the new xfs_sync_data and xfs_sync_attr function and
fix the one place that did pass in a wrong flag.

Also remove a comment mentioning xfs_sync_inodes that has been incorrect
for a while because we always take either the iolock or ilock in the
sync path these days.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index 6c87c8f304e..edf8bdf4141 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -542,10 +542,8 @@ xfs_filestream_associate(
 	 * waiting for the lock because someone else is waiting on the lock we
 	 * hold and we cannot drop that as we are in a transaction here.
 	 *
-	 * Lucky for us, this inversion is rarely a problem because it's a
-	 * directory inode that we are trying to lock here and that means the
-	 * only place that matters is xfs_sync_inodes() and SYNC_DELWRI is
-	 * used. i.e. freeze, remount-ro, quotasync or unmount.
+	 * Lucky for us, this inversion is not a problem because it's a
+	 * directory inode that we are trying to lock here.
 	 *
 	 * So, if we can't get the iolock without sleeping then just give up
 	 */