vfs: ignore error on forced remount

On emergency remount we want to force MS_RDONLY on the super block
even if ->remount_fs() failed for some reason.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/super.c b/fs/super.c
index 32a81f3467e0..afd0f1ad45e0 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -727,8 +727,13 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
 
         if (sb->s_op->remount_fs) {
                 retval = sb->s_op->remount_fs(sb, &flags, data);
-                if (retval)
-                        return retval;
+                if (retval) {
+                        if (!force)
+                                return retval;
+                        /* If forced remount, go ahead despite any errors */
+                        WARN(1, "forced remount of a %s fs returned %i\n",
+                             sb->s_type->name, retval);
+                }
         }
         sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);