From mboxrd@z Thu Jan 1 00:00:00 1970 From: Namjae Jeon Subject: [PATCH 5/8] nbd: use generic helper to set max_discard_sectors Date: Sat, 13 Apr 2013 22:39:18 +0900 Message-ID: <1365860358-21363-1-git-send-email-linkinjeon@gmail.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: dwmw2@infradead.org, axboe@kernel.dk, shli@kernel.org, Paul.Clements@steeleye.com, npiggin@kernel.dk, neilb@suse.de, cjb@laptop.org, adrian.hunter@intel.com Cc: linux-mtd@lists.infradead.org, nbd-general@lists.sourceforge.net, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Namjae Jeon , Namjae Jeon , Vivek Trivedi List-Id: linux-mmc@vger.kernel.org From: Namjae Jeon It is better to use blk_queue_max_discard_sectors helper function to set max_discard_sectors as it checks max_discard_sectors upper limit UINT_MAX >> 9 similar issue was reported for mmc in below link https://lkml.org/lkml/2013/4/1/292 If multiple discard requests get merged, merged discard request's size exceeds 4GB, there is possibility that merged discard request's __data_len field may overflow. This patch fixes this issue. Signed-off-by: Namjae Jeon Signed-off-by: Vivek Trivedi --- drivers/block/nbd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 7fecc78..0a081bc 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -854,7 +854,7 @@ static int __init nbd_init(void) */ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); disk->queue->limits.discard_granularity = 512; - disk->queue->limits.max_discard_sectors = UINT_MAX; + blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9); disk->queue->limits.discard_zeroes_data = 0; } -- 1.7.9.5