From e03a72e13648ac6277bf2bab6b8324d51f89c0fa Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Mon, 11 Jan 2010 03:21:51 -0500 Subject: [PATCH] block: Stop using byte offsets All callers of the stacking functions use 512-byte sector units rather than byte offsets. Simplify the code so the stacking functions take sectors when specifying data offsets. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-settings.c | 26 +++++++++----------------- fs/partitions/check.c | 7 ++++--- include/linux/blkdev.h | 17 +++++------------ 3 files changed, 18 insertions(+), 32 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 5eeb9e0d256e..78549c723783 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -507,7 +507,7 @@ static unsigned int lcm(unsigned int a, unsigned int b) * blk_stack_limits - adjust queue_limits for stacked devices * @t: the stacking driver limits (top device) * @b: the underlying queue limits (bottom, component device) - * @offset: offset to beginning of data within component device + * @start: first data sector within component device * * Description: * This function is used by stacking drivers like MD and DM to ensure @@ -525,10 +525,9 @@ static unsigned int lcm(unsigned int a, unsigned int b) * the alignment_offset is undefined. */ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, - sector_t offset) + sector_t start) { - sector_t alignment; - unsigned int top, bottom, ret = 0; + unsigned int top, bottom, alignment, ret = 0; t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); @@ -548,7 +547,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->misaligned |= b->misaligned; - alignment = queue_limit_alignment_offset(b, offset); + alignment = queue_limit_alignment_offset(b, start); /* Bottom device has different alignment. Check that it is * compatible with the current top alignment. @@ -611,11 +610,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, /* Discard alignment and granularity */ if (b->discard_granularity) { - unsigned int granularity = b->discard_granularity; - offset &= granularity - 1; - - alignment = (granularity + b->discard_alignment - offset) - & (granularity - 1); + alignment = queue_limit_discard_alignment(b, start); if (t->discard_granularity != 0 && t->discard_alignment != alignment) { @@ -657,7 +652,7 @@ int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, start += get_start_sect(bdev); - return blk_stack_limits(t, &bq->limits, start << 9); + return blk_stack_limits(t, &bq->limits, start); } EXPORT_SYMBOL(bdev_stack_limits); @@ -668,9 +663,8 @@ EXPORT_SYMBOL(bdev_stack_limits); * @offset: offset to beginning of data within component device * * Description: - * Merges the limits for two queues. Returns 0 if alignment - * didn't change. Returns -1 if adding the bottom device caused - * misalignment. + * Merges the limits for a top level gendisk and a bottom level + * block_device. */ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, sector_t offset) @@ -678,9 +672,7 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, struct request_queue *t = disk->queue; struct request_queue *b = bdev_get_queue(bdev); - offset += get_start_sect(bdev) << 9; - - if (blk_stack_limits(&t->limits, &b->limits, offset) < 0) { + if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) { char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; disk_name(disk, 0, top); diff --git a/fs/partitions/check.c b/fs/partitions/check.c index 64bc8998ac9a..e8865c11777f 100644 --- a/fs/partitions/check.c +++ b/fs/partitions/check.c @@ -412,9 +412,10 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, pdev = part_to_dev(p); p->start_sect = start; - p->alignment_offset = queue_sector_alignment_offset(disk->queue, start); - p->discard_alignment = queue_sector_discard_alignment(disk->queue, - start); + p->alignment_offset = + queue_limit_alignment_offset(&disk->queue->limits, start); + p->discard_alignment = + queue_limit_discard_alignment(&disk->queue->limits, start); p->nr_sects = len; p->partno = partno; p->policy = get_disk_ro(disk); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5c8018977efa..ffb13ad35716 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1112,18 +1112,13 @@ static inline int queue_alignment_offset(struct request_queue *q) return q->limits.alignment_offset; } -static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t offset) +static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) { unsigned int granularity = max(lim->physical_block_size, lim->io_min); + unsigned int alignment = (sector << 9) & (granularity - 1); - offset &= granularity - 1; - return (granularity + lim->alignment_offset - offset) & (granularity - 1); -} - -static inline int queue_sector_alignment_offset(struct request_queue *q, - sector_t sector) -{ - return queue_limit_alignment_offset(&q->limits, sector << 9); + return (granularity + lim->alignment_offset - alignment) + & (granularity - 1); } static inline int bdev_alignment_offset(struct block_device *bdev) @@ -1147,10 +1142,8 @@ static inline int queue_discard_alignment(struct request_queue *q) return q->limits.discard_alignment; } -static inline int queue_sector_discard_alignment(struct request_queue *q, - sector_t sector) +static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) { - struct queue_limits *lim = &q->limits; unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); return (lim->discard_granularity + lim->discard_alignment - alignment) -- 2.25.1