block: fix problem with sending down discard that isn't of correct granularity
If the queue doesn't have a limit set, or it just set UINT_MAX like
we default to, we coud be sending down a discard request that isn't
of the correct granularity if the block size is > 512b.
Fix this by adjusting max_discard_sectors down to the proper
alignment.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/block/blk-lib.c b/block/blk-lib.c
index e16185b..5d793e1 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -41,6 +41,7 @@
struct request_queue *q = bdev_get_queue(bdev);
int type = flags & BLKDEV_IFL_BARRIER ?
DISCARD_BARRIER : DISCARD_NOBARRIER;
+ unsigned int max_discard_sectors;
struct bio *bio;
int ret = 0;
@@ -50,10 +51,18 @@
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
- while (nr_sects && !ret) {
- unsigned int max_discard_sectors =
- min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ /*
+ * Ensure that max_discard_sectors is of the proper
+ * granularity
+ */
+ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ if (q->limits.discard_granularity) {
+ unsigned int disc_sects = q->limits.discard_granularity >> 9;
+ max_discard_sectors &= ~(disc_sects - 1);
+ }
+
+ while (nr_sects && !ret) {
bio = bio_alloc(gfp_mask, 1);
if (!bio) {
ret = -ENOMEM;