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authorPaolo Bonzini <pbonzini@redhat.com>2012-08-02 09:48:49 +0200
committerJens Axboe <axboe@kernel.dk>2012-08-02 09:48:49 +0200
commitf6ff53d3611b564661896be23369b54d84941a0e (patch)
tree9a6128ce4f3f86e327d088c42e4ddd7002bb410b /block
parent1a9b4993b70fb1884716902774dc9025b457760d (diff)
downloadlinux-f6ff53d3611b564661896be23369b54d84941a0e.tar.gz
block: reorganize rounding of max_discard_sectors
Mostly a preparation for the next patch. In principle this fixes an infinite loop if max_discard_sectors < granularity, but that really shouldn't happen. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-lib.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 2b461b496a7..16b06f62e68 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -44,6 +44,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
struct request_queue *q = bdev_get_queue(bdev);
int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
+ unsigned int granularity;
struct bio_batch bb;
struct bio *bio;
int ret = 0;
@@ -54,18 +55,18 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
+ /* Zero-sector (unknown) and one-sector granularities are the same. */
+ granularity = max(q->limits.discard_granularity >> 9, 1U);
+
/*
* Ensure that max_discard_sectors is of the proper
* granularity
*/
max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ max_discard_sectors = round_down(max_discard_sectors, granularity);
if (unlikely(!max_discard_sectors)) {
/* Avoid infinite loop below. Being cautious never hurts. */
return -EOPNOTSUPP;
- } else if (q->limits.discard_granularity) {
- unsigned int disc_sects = q->limits.discard_granularity >> 9;
-
- max_discard_sectors &= ~(disc_sects - 1);
}
if (flags & BLKDEV_DISCARD_SECURE) {