From 8f50e358153dd68182c714626be4a90b64179cf4 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Mon, 18 Dec 2017 20:22:08 +0800
Subject: [PATCH] dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE
Git-commit: 8f50e358153dd68182c714626be4a90b64179cf4
Patch-mainline: v4.16-rc1
References: bsc#1093023
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>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index de17b7193299..7475739fee49 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -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;
}
--
2.16.3