Ocfs2 devel - Mar 2016 - [patch 18/25] ocfs2: solve a problem of crossing the boundary in updating backups

From: jiangyiwen <jiangyiwen at huawei.com>
Subject: ocfs2: solve a problem of crossing the boundary in updating backups

In update_backups() there exists a problem of crossing the boundary
as follows:

we assume that lun will be resized to 1TB(cluster_size is 32kb),
it will include 0~33554431 cluster, in update_backups func,
it will backup super block in location of 1TB which is the 33554432th
cluster, so the phenomenon of crossing the boundary happens.

Signed-off-by: Yiwen Jiang <jiangyiwen at huawei.com>
Reviewed-by: Joseph Qi <joseph.qi at huawei.com>
Cc: Xue jiufei <xuejiufei at huawei.com>
Cc: Mark Fasheh <mfasheh at suse.de>
Cc: Joel Becker <jlbec at evilplan.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
---

 fs/ocfs2/resize.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN
fs/ocfs2/resize.c~ocfs2-solve-a-problem-of-crossing-the-boundary-in-updating-backups
fs/ocfs2/resize.c
---
a/fs/ocfs2/resize.c~ocfs2-solve-a-problem-of-crossing-the-boundary-in-updating-backups
+++ a/fs/ocfs2/resize.c
@@ -196,7 +196,7 @@ static int update_backups(struct inode *
 	for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
 		blkno = ocfs2_backup_super_blkno(inode->i_sb, i);
 		cluster = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
-		if (cluster > clusters)
+		if (cluster >= clusters)
 			break;
 
 		ret = ocfs2_read_blocks_sync(osb, blkno, 1, &backup);
_