[PATCH 2/2] ocfs2: fix the la space leak when unmounting an ocfs2 volume

[Heming Zhao]

This bug has existed since the initial OCFS2 code.  The code logic in
ocfs2_sync_local_to_main() is wrong, as it ignores the last contiguous
free bits, which causes an OCFS2 volume to lose the last free clusters of
LA window on each umount command.

Signed-off-by: Heming Zhao <heming.zhao@xxxxxxxx>
Fixes: 30dd3478c3cd ("ocfs2: correctly use ocfs2_find_next_zero_bit()")
---
 fs/ocfs2/localalloc.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index 5df34561c551..8ac42ea81a17 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -1002,6 +1002,25 @@ static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
 		start = bit_off + 1;
 	}
 
+	/* clear the contiguous bits until the end boundary */
+	if (count) {
+		blkno = la_start_blk +
+			ocfs2_clusters_to_blocks(osb->sb,
+					start - count);
+
+		trace_ocfs2_sync_local_to_main_free(
+				count, start - count,
+				(unsigned long long)la_start_blk,
+				(unsigned long long)blkno);
+
+		status = ocfs2_release_clusters(handle,
+				main_bm_inode,
+				main_bm_bh, blkno,
+				count);
+		if (status < 0)
+			mlog_errno(status);
+	}
+
 bail:
 	if (status)
 		mlog_errno(status);
-- 
2.43.0