UBIFS: return sensible error codes

When mounting/re-mounting, UBIFS returns EINVAL even if the ENOSPC
or EROFS codes are are much better, just because we have not found
references to ENOSPC/EROFS in mount (2) man pages. This patch
changes this behaviour and makes UBIFS return real error code,
because:

1. It is just less confusing and more logical
2. mount is not described in SuSv3, so it seems to be not really
   well-standartized
3. we do not cover all cases, and any random undocumented in man
   pages error code may be returned anyway

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

2 files changed, 4 insertions, 9 deletions

diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 71d5493bf56..a88f33801b9 100644
--- a/fs/ubifs/master.c
+++ b/fs/ubifs/master.c
@@ -354,7 +354,7 @@ int ubifs_write_master(struct ubifs_info *c)
         int err, lnum, offs, len;
 
         if (c->ro_media)
-                return -EINVAL;
+                return -EROFS;
 
         lnum = UBIFS_MST_LNUM;
         offs = c->mst_offs + c->mst_node_alsz;
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index daa679d3a03..ab85eb8cce7 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1085,12 +1085,7 @@ static int check_free_space(struct ubifs_info *c)
                 ubifs_err("insufficient free space to mount in read/write mode");
                 dbg_dump_budg(c);
                 dbg_dump_lprops(c);
-                /*
-                 * We return %-EINVAL instead of %-ENOSPC because it seems to
-                 * be the closest error code mentioned in the mount function
-                 * documentation.
-                 */
-                return -EINVAL;
+                return -ENOSPC;
         }
         return 0;
 }
@@ -1790,7 +1785,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
                 if (c->ro_media) {
                         ubifs_msg("cannot re-mount due to prior errors");
-                        return -EINVAL;
+                        return -EROFS;
                 }
                 err = ubifs_remount_rw(c);
                 if (err)
@@ -1798,7 +1793,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
         } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
                 if (c->ro_media) {
                         ubifs_msg("cannot re-mount due to prior errors");
-                        return -EINVAL;
+                        return -EROFS;
                 }
                 ubifs_remount_ro(c);
         }