[PATCH] ubifs: Check ubifs_wbuf_sync() return code

[Richard Weinberger]

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.

Cc: <stable at vger.kernel.org>
Fixes: 1e51764a3c2a ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard at nod.at>
---
 fs/ubifs/super.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 0beb285b143d..468bca452d0a 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1739,8 +1739,11 @@ static void ubifs_remount_ro(struct ubifs_info *c)
 
 	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);
@@ -1806,8 +1809,11 @@ static void ubifs_put_super(struct super_block *sb)
 			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
-- 
2.13.6