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, 34 insertions, 21 deletions

diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index a3d2e771306..c1a9a113507 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -268,29 +268,42 @@ xfs_sync_inode_attr(
 	return error;
 }
 
+/*
+ * Write out pagecache data for the whole filesystem.
+ */
 int
-xfs_sync_inodes(
-	xfs_mount_t	*mp,
-	int		flags)
+xfs_sync_data(
+	struct xfs_mount	*mp,
+	int			flags)
 {
-	int		error = 0;
-	int		lflags = XFS_LOG_FORCE;
+	int			error;
 
-	if (mp->m_flags & XFS_MOUNT_RDONLY)
-		return 0;
+	ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT|SYNC_IOWAIT)) == 0);
 
-	if (flags & SYNC_WAIT)
-		lflags |= XFS_LOG_SYNC;
+	error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags,
+				      XFS_ICI_NO_TAG);
+	if (error)
+		return XFS_ERROR(error);
 
-	if (flags & SYNC_DELWRI)
-		error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags, XFS_ICI_NO_TAG);
+	xfs_log_force(mp, 0,
+		      (flags & SYNC_WAIT) ?
+		       XFS_LOG_FORCE | XFS_LOG_SYNC :
+		       XFS_LOG_FORCE);
+	return 0;
+}
 
-	if (flags & SYNC_ATTR)
-		error = xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags, XFS_ICI_NO_TAG);
+/*
+ * Write out inode metadata (attributes) for the whole filesystem.
+ */
+int
+xfs_sync_attr(
+	struct xfs_mount	*mp,
+	int			flags)
+{
+	ASSERT((flags & ~SYNC_WAIT) == 0);
 
-	if (!error && (flags & SYNC_DELWRI))
-		xfs_log_force(mp, 0, lflags);
-	return XFS_ERROR(error);
+	return xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags,
+				     XFS_ICI_NO_TAG);
 }
 
 STATIC int
@@ -404,12 +417,12 @@ xfs_quiesce_data(
 	int error;
 
 	/* push non-blocking */
-	xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_BDFLUSH);
+	xfs_sync_data(mp, 0);
 	xfs_qm_sync(mp, SYNC_BDFLUSH);
 	xfs_filestream_flush(mp);
 
 	/* push and block */
-	xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_WAIT|SYNC_IOWAIT);
+	xfs_sync_data(mp, SYNC_WAIT|SYNC_IOWAIT);
 	xfs_qm_sync(mp, SYNC_WAIT);
 
 	/* write superblock and hoover up shutdown errors */
@@ -438,7 +451,7 @@ xfs_quiesce_fs(
 	 * logged before we can write the unmount record.
 	 */
 	do {
-		xfs_sync_inodes(mp, SYNC_ATTR|SYNC_WAIT);
+		xfs_sync_attr(mp, SYNC_WAIT);
 		pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1);
 		if (!pincount) {
 			delay(50);
@@ -521,8 +534,8 @@ xfs_flush_inodes_work(
 	void		*arg)
 {
 	struct inode	*inode = arg;
-	xfs_sync_inodes(mp, SYNC_DELWRI | SYNC_TRYLOCK);
-	xfs_sync_inodes(mp, SYNC_DELWRI | SYNC_TRYLOCK | SYNC_IOWAIT);
+	xfs_sync_data(mp, SYNC_TRYLOCK);
+	xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_IOWAIT);
 	iput(inode);
 }