From e03a72e13648ac6277bf2bab6b8324d51f89c0fa Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Mon, 11 Jan 2010 03:21:51 -0500 Subject: 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 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) (limited to 'block') 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); -- cgit v1.2.3