diff mbox

[v2,10/51] dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE

Message ID 20170626121034.3051-11-ming.lei@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ming Lei June 26, 2017, 12:09 p.m. UTC
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
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/md/dm.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 96bd13e581cd..49583c623cdd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -921,7 +921,16 @@  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;
 }