[Devel] [PATCH] ploop: Discard bios of size not aligned at 512 bytes

[Kirill Tkhai]

Currently, we have BUG_ON() on this place. But it's
easy to generate 511 bytes request from userspace,
as it was found by Andrey Vagin via iscsi tests:

sg_raw -r511 /dev/sda 28 0 0 0 0 0 0 0 9 0

This patch replaces BUG_ON() with bio discarding
like other drivers do when they see a size above
their logical block size.

https://jira.sw.ru/browse/PSBM-81576

Reported-by: Andrey Vagin <avagin at virtuozzo.com>
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/block/ploop/dev.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 6c0b3c0252c0..7f079aea0e88 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -846,7 +846,11 @@ static void ploop_make_request(struct request_queue *q, struct bio *bio)
 	plo->st.bio_in++;
 
 	BUG_ON(bio->bi_idx);
-	BUG_ON(bio->bi_size & 511);
+	if (bio->bi_size & 511) {
+		pr_err_once("ploop: dropped bio: bi_size=%u\n", bio->bi_size);
+		BIO_ENDIO(q, bio, -EIO);
+		return;
+	}
 
 	cpu = part_stat_lock();
 	part = disk_map_sector_rcu(plo->disk, bio->bi_sector);