From c4a69ecdb463a901b4645230613961e134e897cd Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 28 Mar 2012 18:41:28 +0100 Subject: dm thin: relax hard limit on the maximum size of a metadata device The thin metadata format can only make use of a device that is <= THIN_METADATA_MAX_SECTORS (currently 15.9375 GB). Therefore, there is no practical benefit to using a larger device. However, it may be that other factors impose a certain granularity for the space that is allocated to a device (E.g. lvm2 can impose a coarse granularity through the use of large, >= 1 GB, physical extents). Rather than reject a larger metadata device, during thin-pool device construction, switch to allowing it but issue a warning if a device larger than THIN_METADATA_MAX_SECTORS_WARNING (16 GB) is provided. Any space over 15.9375 GB will not be used. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-thin-metadata.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/md/dm-thin-metadata.c') diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index a680c761341f..737d38865b69 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -713,6 +713,9 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, if (r) goto bad; + if (bdev_size > THIN_METADATA_MAX_SECTORS) + bdev_size = THIN_METADATA_MAX_SECTORS; + disk_super = dm_block_data(sblock); disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); disk_super->version = cpu_to_le32(THIN_VERSION); -- cgit v1.2.3