From 687cf4412a343a63928a5c9d91bdc0f522939d43 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Fri, 9 Nov 2018 11:56:03 -0500
Subject: [PATCH] dm cache metadata: verify cache has blocks in
blocks_are_clean_separate_dirty()
Git-commit: 687cf4412a343a63928a5c9d91bdc0f522939d43
Patch-mainline: v4.20-rc7
References: git-fixes
Otherwise dm_bitset_cursor_begin() return -ENODATA. Other calls to
dm_bitset_cursor_begin() have similar negative checks.
Fixes inability to create a cache in passthrough mode (even though doing
so makes no sense).
Fixes: 0d963b6e65 ("dm cache metadata: fix metadata2 format's blocks_are_clean_separate_dirty")
Cc: stable@vger.kernel.org
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-cache-metadata.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 5936de71883f..6fc93834da44 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -930,6 +930,10 @@ static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
bool dirty_flag;
*result = true;
+ if (from_cblock(cmd->cache_blocks) == 0)
+ /* Nothing to do */
+ return 0;
+
r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
if (r) {
--
2.16.4