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| author | Geert Uytterhoeven <geert@linux-m68k.org> | 2013-11-04 17:00:06 +0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-11-08 20:04:46 +0400 |
| commit | 97597dc08f58e25bc74154b7d1c387a4c0432950 (patch) | |
| tree | 0d904cb15553db7ee1c624dfa1ae4706da779bfe | |
| parent | f8c5e94486671ffcac696886c246baa6ba89b5cf (diff) | |
| download | linux-97597dc08f58e25bc74154b7d1c387a4c0432950.tar.xz | |
block: Do not call sector_div() with a 64-bit divisor
do_div() (called by sector_div() if CONFIG_LBDAF=y) is meant for divisions
of 64-bit number by 32-bit numbers. Passing 64-bit divisor types caused
issues in the past on 32-bit platforms, cfr. commit
ea077b1b96e073eac5c3c5590529e964767fc5f7 ("m68k: Truncate base in
do_div()").
As queue_limits.max_discard_sectors and .discard_granularity are unsigned
int, max_discard_sectors and granularity should be unsigned int.
As bdev_discard_alignment() returns int, alignment should be int.
Now 2 calls to sector_div() can be replaced by 32-bit arithmetic:
- The 64-bit modulo operation can become a 32-bit modulo operation,
- The 64-bit division and multiplication can be replaced by a 32-bit
modulo operation and a subtraction.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-lib.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index d6f50d572565..9b5b561cb928 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -43,8 +43,8 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, DECLARE_COMPLETION_ONSTACK(wait); struct request_queue *q = bdev_get_queue(bdev); int type = REQ_WRITE | REQ_DISCARD; - sector_t max_discard_sectors; - sector_t granularity, alignment; + unsigned int max_discard_sectors, granularity; + int alignment; struct bio_batch bb; struct bio *bio; int ret = 0; @@ -58,16 +58,14 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, /* Zero-sector (unknown) and one-sector granularities are the same. */ granularity = max(q->limits.discard_granularity >> 9, 1U); - alignment = bdev_discard_alignment(bdev) >> 9; - alignment = sector_div(alignment, granularity); + alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; /* * Ensure that max_discard_sectors is of the proper * granularity, so that requests stay aligned after a split. */ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); - sector_div(max_discard_sectors, granularity); - max_discard_sectors *= granularity; + max_discard_sectors -= max_discard_sectors % granularity; if (unlikely(!max_discard_sectors)) { /* Avoid infinite loop below. Being cautious never hurts. */ return -EOPNOTSUPP; |