Patchwork [8/8] bcache: use generic helper to set max_discard_sectors

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Submitter NamJae Jeon
Date April 13, 2013, 1:40 p.m.
Message ID <1365860416-21499-1-git-send-email-linkinjeon@gmail.com>
Download mbox | patch
Permalink /patch/236354/
State New
Headers show

Comments

NamJae Jeon - April 13, 2013, 1:40 p.m.
From: Namjae Jeon <namjae.jeon@samsung.com>

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@samsung.com>
Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
---
 drivers/md/bcache/super.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f3bf310..d87ab31 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -746,7 +746,7 @@  static int bcache_device_init(struct bcache_device *d, unsigned block_size)
 	q->limits.max_sectors		= UINT_MAX;
 	q->limits.max_segment_size	= UINT_MAX;
 	q->limits.max_segments		= BIO_MAX_PAGES;
-	q->limits.max_discard_sectors	= UINT_MAX;
+	blk_queue_max_discard_sectors(q, UINT_MAX >> 9);
 	q->limits.io_min		= block_size;
 	q->limits.logical_block_size	= block_size;
 	q->limits.physical_block_size	= block_size;