dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE

For BIO based DM, some targets aren't ready for dealing with bigger
incoming bio than 1Mbyte, such as crypt target.

Cc: Mike Snitzer <snitzer@redhat.com>
Cc:dm-devel@redhat.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2017-12-18 20:22:08 +08:00 committed by Jens Axboe
parent 3c892a098b
commit 8f50e35815

View file

@ -920,7 +920,15 @@ int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
return -EINVAL;
}
ti->max_io_len = (uint32_t) len;
/*
* BIO based queue uses its own splitting. When multipage bvecs
* is switched on, size of the incoming bio may be too big to
* be handled in some targets, such as crypt.
*
* When these targets are ready for the big bio, we can remove
* the limit.
*/
ti->max_io_len = min_t(uint32_t, len, BIO_MAX_PAGES * PAGE_SIZE);
return 0;
}