From 86b37281411cf1e9bc0a6b5406c45edb7bd9ea5d Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 10 Nov 2009 11:50:21 +0100 Subject: block: Expose discard granularity While SSDs track block usage on a per-sector basis, RAID arrays often have allocation blocks that are bigger. Allow the discard granularity and alignment to be set and teach the topology stacking logic how to handle them. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 39c601f783a0..1cc02972fbe2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -312,12 +312,15 @@ struct queue_limits { unsigned int io_min; unsigned int io_opt; unsigned int max_discard_sectors; + unsigned int discard_granularity; + unsigned int discard_alignment; unsigned short logical_block_size; unsigned short max_hw_segments; unsigned short max_phys_segments; unsigned char misaligned; + unsigned char discard_misaligned; unsigned char no_cluster; }; @@ -1121,6 +1124,21 @@ static inline int bdev_alignment_offset(struct block_device *bdev) return q->limits.alignment_offset; } +static inline int queue_discard_alignment(struct request_queue *q) +{ + if (q->limits.discard_misaligned) + return -1; + + return q->limits.discard_alignment; +} + +static inline int queue_sector_discard_alignment(struct request_queue *q, + sector_t sector) +{ + return ((sector << 9) - q->limits.discard_alignment) + & (q->limits.discard_granularity - 1); +} + static inline int queue_dma_alignment(struct request_queue *q) { return q ? q->dma_alignment : 511; -- cgit v1.2.3