[XFS] Propagate errors from xfs_trans_commit().

xfs_trans_commit() can return errors when there are problems in the
transaction subsystem. They are indicative that the entire transaction may
be incomplete, and hence the error should be propagated as there is a good
possibility that there is something fatally wrong in the filesystem. Catch
and propagate or warn about commit errors in the places where they are
currently ignored.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30795a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 244aa1b..2d03fe1 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -45,7 +45,7 @@
 #include "xfs_fsops.h"
 #include "xfs_utils.h"
 
-STATIC void	xfs_mount_log_sb(xfs_mount_t *, __int64_t);
+STATIC int	xfs_mount_log_sb(xfs_mount_t *, __int64_t);
 STATIC int	xfs_uuid_mount(xfs_mount_t *);
 STATIC void	xfs_uuid_unmount(xfs_mount_t *mp);
 STATIC void	xfs_unmountfs_wait(xfs_mount_t *);
@@ -1189,8 +1189,13 @@
 	/*
 	 * If fs is not mounted readonly, then update the superblock changes.
 	 */
-	if (update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY))
-		xfs_mount_log_sb(mp, update_flags);
+	if (update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
+		error = xfs_mount_log_sb(mp, update_flags);
+		if (error) {
+			cmn_err(CE_WARN, "XFS: failed to write sb changes");
+			goto error4;
+		}
+	}
 
 	/*
 	 * Initialise the XFS quota management subsystem for this mount
@@ -1320,8 +1325,10 @@
 		cmn_err(CE_WARN, "XFS: Unable to free reserved block pool. "
 				"Freespace may not be correct on next mount.");
 
-
-	xfs_log_sbcount(mp, 1);
+	error = xfs_log_sbcount(mp, 1);
+	if (error)
+		cmn_err(CE_WARN, "XFS: Unable to update superblock counters. "
+				"Freespace may not be correct on next mount.");
 	xfs_unmountfs_writesb(mp);
 	xfs_unmountfs_wait(mp); 		/* wait for async bufs */
 	xfs_log_unmount(mp);			/* Done! No more fs ops. */
@@ -1413,9 +1420,8 @@
 	xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
 	if (sync)
 		xfs_trans_set_sync(tp);
-	xfs_trans_commit(tp, 0);
-
-	return 0;
+	error = xfs_trans_commit(tp, 0);
+	return error;
 }
 
 STATIC void
@@ -1913,24 +1919,27 @@
  * be altered by the mount options, as well as any potential sb_features2
  * fixup. Only the first superblock is updated.
  */
-STATIC void
+STATIC int
 xfs_mount_log_sb(
 	xfs_mount_t	*mp,
 	__int64_t	fields)
 {
 	xfs_trans_t	*tp;
+	int		error;
 
 	ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
 			 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2));
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
-	if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
-				XFS_DEFAULT_LOG_COUNT)) {
+	error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+				XFS_DEFAULT_LOG_COUNT);
+	if (error) {
 		xfs_trans_cancel(tp, 0);
-		return;
+		return error;
 	}
 	xfs_mod_sb(tp, fields);
-	xfs_trans_commit(tp, 0);
+	error = xfs_trans_commit(tp, 0);
+	return error;
 }