[Nbd] [PATCH v2 6/9] nbd: use generic helper to set max_discard_sectors
- To: dwmw2@...1270..., axboe@...161..., shli@...1285..., Paul.Clements@...124..., npiggin@...161..., neilb@...122..., cjb@...1330..., adrian.hunter@...1303..., James.Bottomley@...1336..., JBottomley@...1298...
- Cc: nbd-general@lists.sourceforge.net, Namjae Jeon <linkinjeon@...17...>, Vivek Trivedi <t.vivek@...1329...>, linux-scsi@...25..., Namjae Jeon <namjae.jeon@...1329...>, linux-mmc@...25..., linux-kernel@...25..., linux-raid@...25..., jcmvbkbc@...17..., linux-mtd@...1331...
- Subject: [Nbd] [PATCH v2 6/9] nbd: use generic helper to set max_discard_sectors
- From: Namjae Jeon <linkinjeon@...17...>
- Date: Sat, 20 Apr 2013 01:41:53 +0900
- Message-id: <1366389713-19519-1-git-send-email-linkinjeon@...17...>
From: Namjae Jeon <namjae.jeon@...1329...>
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 <namjae.jeon@...1329...>
Signed-off-by: Vivek Trivedi <t.vivek@...1329...>
---
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 037288e..b9d3d2e 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;
blk_queue_max_hw_sectors(disk->queue, 65536);
disk->queue->limits.max_sectors = 256;
--
1.7.9.5
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