The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 4561ffca88c546f96367f94b8f1e4715a9c62314 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@xxxxxxxxxx>
Date: Mon, 24 Sep 2018 16:19:30 -0400
Subject: [PATCH] dm cache metadata: ignore hints array being too small during
resize
Commit fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to
on-disk superblock") enabled previously written policy hints to be
used after a cache is reactivated. But in doing so the cache
metadata's hint array was left exposed to out of bounds access because
on resize the metadata's on-disk hint array wasn't ever extended.
Fix this by ignoring that there are no on-disk hints associated with the
newly added cache blocks. An expanded on-disk hint array is later
rewritten upon the next clean shutdown of the cache.
Fixes: fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 69dddeab124c..5936de71883f 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1455,8 +1455,8 @@ static int __load_mappings(struct dm_cache_metadata *cmd,
if (hints_valid) {
r = dm_array_cursor_next(&cmd->hint_cursor);
if (r) {
- DMERR("dm_array_cursor_next for hint failed");
- goto out;
+ dm_array_cursor_end(&cmd->hint_cursor);
+ hints_valid = false;
}
}
