Merge tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifs

Pull UBIFS fixes from Artem Bityutskiy:
 "Two patches which fix a problem reported by several people in the
  past, but only fixed now because no one gave enough material for
  debugging.

  Anyway, these fix the problem that sometimes after a power cut the
  file-system is not mountable with the following symptom:

	grab_empty_leb: could not find an empty LEB

  The fixes make the file-system mountable again."

* tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifs:
  UBIFS: fix mounting problems after power cuts
  UBIFS: introduce categorized lprops counter

fs/ubifs/find.c

@@ -681,8 +681,16 @@ int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
 	if (!lprops) {
 		lprops = ubifs_fast_find_freeable(c);
 		if (!lprops) {
-			ubifs_assert(c->freeable_cnt == 0);
+			/*
-			if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
+			 * The first condition means the following: go scan the
+			 * LPT if there are uncategorized lprops, which means
+			 * there may be freeable LEBs there (UBIFS does not
+			 * store the information about freeable LEBs in the
+			 * master node).
+			 */
+			if (c->in_a_category_cnt != c->main_lebs ||
+			    c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
+				ubifs_assert(c->freeable_cnt == 0);
 				lprops = scan_for_leb_for_idx(c);
 				if (IS_ERR(lprops)) {
 					err = PTR_ERR(lprops);

fs/ubifs/lprops.c

@@ -300,8 +300,11 @@ void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
 	default:
 		ubifs_assert(0);
 	}
+
 	lprops->flags &= ~LPROPS_CAT_MASK;
 	lprops->flags |= cat;
+	c->in_a_category_cnt += 1;
+	ubifs_assert(c->in_a_category_cnt <= c->main_lebs);
 }
 
 /**
@@ -334,6 +337,9 @@ static void ubifs_remove_from_cat(struct ubifs_info *c,
 	default:
 		ubifs_assert(0);
 	}
+
+	c->in_a_category_cnt -= 1;
+	ubifs_assert(c->in_a_category_cnt >= 0);
 }
 
 /**

fs/ubifs/ubifs.h

@@ -1183,6 +1183,8 @@ struct ubifs_debug_info;
  * @freeable_list: list of freeable non-index LEBs (free + dirty == @leb_size)
  * @frdi_idx_list: list of freeable index LEBs (free + dirty == @leb_size)
  * @freeable_cnt: number of freeable LEBs in @freeable_list
+ * @in_a_category_cnt: count of lprops which are in a certain category, which
+ *                     basically meants that they were loaded from the flash
  *
  * @ltab_lnum: LEB number of LPT's own lprops table
  * @ltab_offs: offset of LPT's own lprops table
@@ -1412,6 +1414,7 @@ struct ubifs_info {
 	struct list_head freeable_list;
 	struct list_head frdi_idx_list;
 	int freeable_cnt;
+	int in_a_category_cnt;
 
 	int ltab_lnum;
 	int ltab_offs;