[PATCH] UBIFS: fix master node recovery

[Anatolij Gustschin]

When the 1st LEB was unmapped and written but 2nd LEB not,
the master node recovery doesn't succeed after power cut.
We see following error when mounting UBIFS partition on NOR
flash:

UBIFS error (pid 1137): ubifs_recover_master_node: failed to recover master node

Additional 2nd master node offset check is needed to fix the
problem. If the 2nd master node is at the end in the 2nd LEB,
first master node is used for recovery.

Signed-off-by: Anatolij Gustschin <agust at denx.de>
---
 fs/ubifs/recovery.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c
index 783d8e0..0e951f0 100644
--- a/fs/ubifs/recovery.c
+++ b/fs/ubifs/recovery.c
@@ -274,7 +274,9 @@ int ubifs_recover_master_node(struct ubifs_info *c)
 				if (cor1)
 					goto out_err;
 				mst = mst1;
-			} else if (offs1 == 0 && offs2 + sz >= c->leb_size) {
+			} else if (offs1 == 0 &&
+				   (offs2 + sz >= c->leb_size ||
+				    (c->leb_size - offs2 - sz) < sz)) {
 				/* 1st LEB was unmapped and written, 2nd not */
 				if (cor1)
 					goto out_err;
-- 
1.7.1