UBIFS: remount ro fixes

- preserve the idx_gc list - it will be needed in the same
state, should UBIFS be remounted rw again
- prevent remounting ro if we have switched to read only
mode (due to a fatal error)

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

3 files changed, 13 insertions, 21 deletions

diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
index bad3339a800d..a711d33b3d3e 100644
--- a/fs/ubifs/gc.c
+++ b/fs/ubifs/gc.c
@@ -830,29 +830,21 @@ out:
  * ubifs_destroy_idx_gc - destroy idx_gc list.
  * @c: UBIFS file-system description object
  *
- * This function destroys the @c->idx_gc list. It is called when unmounting or
- * remounting read-only so locks are not needed. Returns zero in case of
- * success and a negative error code in case of failure.
+ * This function destroys the @c->idx_gc list. It is called when unmounting
+ * so locks are not needed. Returns zero in case of success and a negative
+ * error code in case of failure.
  */
-int ubifs_destroy_idx_gc(struct ubifs_info *c)
+void ubifs_destroy_idx_gc(struct ubifs_info *c)
 {
-        int ret = 0;
-
         while (!list_empty(&c->idx_gc)) {
-                int err;
                 struct ubifs_gced_idx_leb *idx_gc;
 
                 idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb,
                                     list);
-                err = ubifs_change_one_lp(c, idx_gc->lnum, LPROPS_NC,
-                                          LPROPS_NC, 0, LPROPS_TAKEN, -1);
-                if (err && !ret)
-                        ret = err;
+                c->idx_gc_cnt -= 1;
                 list_del(&idx_gc->list);
                 kfree(idx_gc);
         }
-
-        return ret;
 }
 
 /**
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 3ddd754262b4..daa679d3a03e 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1687,10 +1687,6 @@ static void ubifs_remount_ro(struct ubifs_info *c)
         if (err)
                 ubifs_ro_mode(c, err);
 
-        err = ubifs_destroy_idx_gc(c);
-        if (err)
-                ubifs_ro_mode(c, err);
-
         free_wbufs(c);
         vfree(c->orph_buf);
         c->orph_buf = NULL;
@@ -1793,15 +1789,19 @@ 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 R/W, UBIFS is working in "
-                                  "R/O mode");
+                        ubifs_msg("cannot re-mount due to prior errors");
                         return -EINVAL;
                 }
                 err = ubifs_remount_rw(c);
                 if (err)
                         return err;
-        } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
+        } 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;
+                }
                 ubifs_remount_ro(c);
+        }
 
         if (c->bulk_read == 1)
                 bu_init(c);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 29dfa816077b..535f87426791 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1594,7 +1594,7 @@ int ubifs_replay_journal(struct ubifs_info *c);
 int ubifs_garbage_collect(struct ubifs_info *c, int anyway);
 int ubifs_gc_start_commit(struct ubifs_info *c);
 int ubifs_gc_end_commit(struct ubifs_info *c);
-int ubifs_destroy_idx_gc(struct ubifs_info *c);
+void ubifs_destroy_idx_gc(struct ubifs_info *c);
 int ubifs_get_idx_gc_leb(struct ubifs_info *c);
 int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp);