From 2dbe5495763612f7c1b68fc897cd28c9e22079b8 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.com>
Date: Wed, 4 Nov 2015 17:13:39 +0100
Subject: [PATCH] brd: Refuse improperly aligned discard requests
Currently when improperly aligned discard request is submitted, we just
silently discard more / less data which results in filesystem corruption
in some cases. Refuse such misaligned requests.
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
drivers/block/brd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index c9f9c30d64675..a5880f4ab40eb 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -337,6 +337,9 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
goto io_error;
if (unlikely(bio->bi_rw & REQ_DISCARD)) {
+ if (sector & ((PAGE_SIZE >> SECTOR_SHIFT) - 1) ||
+ bio->bi_iter.bi_size & PAGE_MASK)
+ goto io_error;
discard_from_brd(brd, sector, bio->bi_iter.bi_size);
goto out;
}
--
GitLab