This is a note to let you know that I've just added the patch titled
dm thin metadata: do not allow the data block size to change
to the 3.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-thin-metadata-do-not-allow-the-data-block-size-to-change.patch
and it can be found in the queue-3.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9aec8629ec829fc9403788cd959e05dd87988bd1 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@xxxxxxxxxx>
Date: Mon, 14 Jul 2014 16:35:54 -0400
Subject: dm thin metadata: do not allow the data block size to change
From: Mike Snitzer <snitzer@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-thin-metadata.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -613,6 +613,15 @@ static int __open_metadata(struct dm_poo
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;
Patches currently in stable-queue which might be from snitzer@xxxxxxxxxx are
queue-3.15/dm-thin-metadata-do-not-allow-the-data-block-size-to-change.patch
queue-3.15/dm-cache-metadata-do-not-allow-the-data-block-size-to-change.patch
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