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authorMike Snitzer <snitzer@redhat.com>2014-07-14 16:35:54 -0400
committerJiri Slaby <jslaby@suse.cz>2014-07-29 17:01:46 +0200
commitc355b2e35e910d4aa740c4009d5cd62b0698c6c2 (patch)
treedabf66e5b4dc1be92efe1ca864d99748969d2400
parentb2a13535522c598f332f182dcacab0557ea44b0e (diff)
dm thin metadata: do not allow the data block size to change
commit 9aec8629ec829fc9403788cd959e05dd87988bd1 upstream. The block size for the thin-pool's data device must remained fixed for the life of the thin-pool. Disallow any attempt to change the thin-pool's data block size. It should be noted that attempting to change the data block size via thin-pool table reload will be ignored as a side-effect of the thin-pool handover that the thin-pool target does during thin-pool table reload. Here is an example outcome of attempting to load a thin-pool table that reduced the thin-pool's data block size from 1024K to 512K. Before: kernel: device-mapper: thin: 253:4: growing the data device from 204800 to 409600 blocks After: kernel: device-mapper: thin metadata: changing the data block size (from 2048 to 1024) is not supported kernel: device-mapper: table: 253:4: thin-pool: Error creating metadata object kernel: device-mapper: ioctl: error adding target to table Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r--drivers/md/dm-thin-metadata.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 07a6ea3a982..b63095c73b5 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -613,6 +613,15 @@ static int __open_metadata(struct dm_pool_metadata *pmd)
disk_super = dm_block_data(sblock);
+ /* Verify the data block size hasn't changed */
+ if (le32_to_cpu(disk_super->data_block_size) != pmd->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)pmd->data_block_size);
+ r = -EINVAL;
+ goto bad_unlock_sblock;
+ }
+
r = __check_incompat_features(disk_super, pmd);
if (r < 0)
goto bad_unlock_sblock;