From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> https://lkml.org/lkml/2013/4/1/292 As per above discussion, it has been oberved that few drivers are setting q->limits.max_discard_sectors to more than (UINT_MAX >> 9) 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. Also, adding BLK_DEF_MAX_DISCARD_SECTORS macro to use it instead of UINT_MAX >> 9. Reported-by: Max Filippov <jcmvbkbc@xxxxxxxxx> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Signed-off-by: Vivek Trivedi <t.vivek@xxxxxxxxxxx> --- block/blk-settings.c | 3 ++- include/linux/blkdev.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index c50ecf0..34e6b61 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -283,7 +283,8 @@ EXPORT_SYMBOL(blk_queue_max_hw_sectors); void blk_queue_max_discard_sectors(struct request_queue *q, unsigned int max_discard_sectors) { - q->limits.max_discard_sectors = max_discard_sectors; + q->limits.max_discard_sectors = min_t(unsigned int, max_discard_sectors, + BLK_DEF_MAX_DISCARD_SECTORS); } EXPORT_SYMBOL(blk_queue_max_discard_sectors); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 07aa5f6..efff505 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1105,6 +1105,7 @@ enum blk_default_limits { BLK_DEF_MAX_SECTORS = 1024, BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, + BLK_DEF_MAX_DISCARD_SECTORS = UINT_MAX >> 9, }; #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
