From 048e5a07f282c57815b3901d4a68a77fa131ce0a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 14 Jul 2014 16:59:39 -0400 Subject: [PATCH] dm cache metadata: do not allow the data block size to change The block size for the dm-cache's data device must remained fixed for the life of the cache. Disallow any attempt to change the cache's data block size. Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Cc: stable@vger.kernel.org --- drivers/md/dm-cache-metadata.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 4ead4ba60656..d2899e7eb3aa 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -425,6 +425,15 @@ static int __open_metadata(struct dm_cache_metadata *cmd) disk_super = dm_block_data(sblock); + /* Verify the data block size hasn't changed */ + if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { + DMERR("changing the data block size (from %u to %llu) is not supported", + le32_to_cpu(disk_super->data_block_size), + (unsigned long long)cmd->data_block_size); + r = -EINVAL; + goto bad; + } + r = __check_incompat_features(disk_super, cmd); if (r < 0) goto bad; -- 2.20.1