1 files changed, 22 insertions, 13 deletions

diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index 0355fe2b04..a07fdef12f 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -98,10 +98,14 @@ static inline long long empty_log_bytes(const struct ubifs_info *c)
 	h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
 	t = (long long)c->ltail_lnum * c->leb_size;
 
-	if (h >= t)
+	if (h > t)
 		return c->log_bytes - h + t;
-	else
+	else if (h != t)
 		return t - h;
+	else if (c->lhead_lnum != c->ltail_lnum)
+		return 0;
+	else
+		return c->log_bytes;
 }
 
 /**
@@ -232,6 +236,7 @@ int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
 
 	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}
 
@@ -396,15 +401,14 @@ int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
 	/* Switch to the next log LEB */
 	if (c->lhead_offs) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}
 
-	if (c->lhead_offs == 0) {
-		/* Must ensure next LEB has been unmapped */
-		err = ubifs_leb_unmap(c, c->lhead_lnum);
-		if (err)
-			goto out;
-	}
+	/* Must ensure next LEB has been unmapped */
+	err = ubifs_leb_unmap(c, c->lhead_lnum);
+	if (err)
+		goto out;
 
 	len = ALIGN(len, c->min_io_size);
 	dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
@@ -439,9 +443,9 @@ out:
  * @ltail_lnum: new log tail LEB number
  *
  * This function is called on when the commit operation was finished. It
- * moves log tail to new position and unmaps LEBs which contain obsolete data.
- * Returns zero in case of success and a negative error code in case of
- * failure.
+ * moves log tail to new position and updates the master node so that it stores
+ * the new log tail LEB number. Returns zero in case of success and a negative
+ * error code in case of failure.
  */
 int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
 {
@@ -469,7 +473,12 @@ int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
 	spin_unlock(&c->buds_lock);
 
 	err = dbg_check_bud_bytes(c);
+	if (err)
+		goto out;
+
+	err = ubifs_write_master(c);
 
+out:
 	mutex_unlock(&c->log_mutex);
 	return err;
 }
@@ -679,7 +688,7 @@ int ubifs_consolidate_log(struct ubifs_info *c)
 	destroy_done_tree(&done_tree);
 	vfree(buf);
 	if (write_lnum == c->lhead_lnum) {
-		ubifs_err("log is too full");
+		ubifs_err(c, "log is too full");
 		return -EINVAL;
 	}
 	/* Unmap remaining LEBs */
@@ -726,7 +735,7 @@ static int dbg_check_bud_bytes(struct ubifs_info *c)
 			bud_bytes += c->leb_size - bud->start;
 
 	if (c->bud_bytes != bud_bytes) {
-		ubifs_err("bad bud_bytes %lld, calculated %lld",
+		ubifs_err(c, "bad bud_bytes %lld, calculated %lld",
 			  c->bud_bytes, bud_bytes);
 		err = -EINVAL;
 	}