[PATCH 3.16 100/366] ubifs: Check ubifs_wbuf_sync() return code

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Richard Weinberger <richard@xxxxxx>

commit aac17948a7ce01fb60b9ee6cf902967a47b3ce26 upstream.

If ubifs_wbuf_sync() fails we must not write a master node with the
dirty marker cleared.
Otherwise it is possible that in case of an IO error while syncing we
mark the filesystem as clean and UBIFS refuses to recover upon next
mount.

Fixes: 1e51764a3c2a ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/ubifs/super.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1726,8 +1726,11 @@ static void ubifs_remount_ro(struct ubif
 
 	dbg_save_space_info(c);
 
-	for (i = 0; i < c->jhead_cnt; i++)
-		ubifs_wbuf_sync(&c->jheads[i].wbuf);
+	for (i = 0; i < c->jhead_cnt; i++) {
+		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+		if (err)
+			ubifs_ro_mode(c, err);
+	}
 
 	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
 	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
@@ -1794,8 +1797,11 @@ static void ubifs_put_super(struct super
 			int err;
 
 			/* Synchronize write-buffers */
-			for (i = 0; i < c->jhead_cnt; i++)
-				ubifs_wbuf_sync(&c->jheads[i].wbuf);
+			for (i = 0; i < c->jhead_cnt; i++) {
+				err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+				if (err)
+					ubifs_ro_mode(c, err);
+			}
 
 			/*
 			 * We are being cleanly unmounted which means the