ocfs2: fix double unlock in case retry after free truncate log

If ocfs2_reserve_cluster_bitmap_bits fails with ENOSPC, it will try to free truncate log and then retry. Since ocfs2_try_to_free_truncate_log will lock/unlock global bitmap inode, we have to unlock it before calling this function. But when retry reserve and it fails with no global bitmap inode lock taken, it will unlock again in error handling branch and BUG.
This issue also exists if no need retry and then ocfs2_inode_lock fails. So fix it.

Changes since v1:
Use ret instead of status to avoid return value overwritten issue.

Fixes 2070ad1aebff ("ocfs2: retry on ENOSPC if sufficient space in

truncate log"

Signed-off-by Joseph Qi <[email protected]>

Signed-off-by Jiufei Xue <[email protected]>

---
  fs/ocfs2/suballoc.c | 14 ++++++++++++--
  1 file changed, 12 insertions(+), 2 deletions(-)

fs/ocfs2/suballoc.c +12 -2

index ea47120..6ad3533 100644
@@ -1199,14 +1199,24 @@ retry:
  			inode_unlock((*ac)->ac_inode);
 
  			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
-			if (ret == 1)
+			if (ret == 1) {
+				iput((*ac)->ac_inode);
+				(*ac)->ac_inode = NULL;
  				goto retry;
+			}
 
  			if (ret < 0)
  				mlog_errno(ret);
 
  			inode_lock((*ac)->ac_inode);
-			ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
+			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
+			if (ret < 0) {
+				mlog_errno(ret);
+				inode_unlock((*ac)->ac_inode);
+				iput((*ac)->ac_inode);
+				(*ac)->ac_inode = NULL;
+				goto bail;
+			}
  		}
  		if (status < 0) {
  			if (status != -ENOSPC)