From: Namjae Jeon <[email protected]>

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 <[email protected]>
Signed-off-by: Vivek Trivedi <[email protected]>
---
 drivers/block/loop.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index b2955b3..aedc341 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -814,7 +814,7 @@ static void loop_config_discard(struct loop_device *lo)
 
        q->limits.discard_granularity = inode->i_sb->s_blocksize;
        q->limits.discard_alignment = 0;
-       q->limits.max_discard_sectors = UINT_MAX >> 9;
+       blk_queue_max_discard_sectors(q, UINT_MAX >> 9);
        q->limits.discard_zeroes_data = 1;
        queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 }
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to