diff options
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5999d8031675..1c3d774d3c83 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1016,6 +1016,19 @@ static inline struct request_queue *bdev_get_queue(struct block_device *bdev) } /* + * The basic unit of block I/O is a sector. It is used in a number of contexts + * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9 + * bytes. Variables of type sector_t represent an offset or size that is a + * multiple of 512 bytes. Hence these two constants. + */ +#ifndef SECTOR_SHIFT +#define SECTOR_SHIFT 9 +#endif +#ifndef SECTOR_SIZE +#define SECTOR_SIZE (1 << SECTOR_SHIFT) +#endif + +/* * blk_rq_pos() : the current sector * blk_rq_bytes() : bytes left in the entire request * blk_rq_cur_bytes() : bytes left in the current segment @@ -1042,12 +1055,12 @@ extern unsigned int blk_rq_err_bytes(const struct request *rq); static inline unsigned int blk_rq_sectors(const struct request *rq) { - return blk_rq_bytes(rq) >> 9; + return blk_rq_bytes(rq) >> SECTOR_SHIFT; } static inline unsigned int blk_rq_cur_sectors(const struct request *rq) { - return blk_rq_cur_bytes(rq) >> 9; + return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT; } /* @@ -1067,7 +1080,8 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, int op) { if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)) - return min(q->limits.max_discard_sectors, UINT_MAX >> 9); + return min(q->limits.max_discard_sectors, + UINT_MAX >> SECTOR_SHIFT); if (unlikely(op == REQ_OP_WRITE_SAME)) return q->limits.max_write_same_sectors; @@ -1376,16 +1390,21 @@ extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, static inline int sb_issue_discard(struct super_block *sb, sector_t block, sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) { - return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), - nr_blocks << (sb->s_blocksize_bits - 9), + return blkdev_issue_discard(sb->s_bdev, + block << (sb->s_blocksize_bits - + SECTOR_SHIFT), + nr_blocks << (sb->s_blocksize_bits - + SECTOR_SHIFT), gfp_mask, flags); } static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, sector_t nr_blocks, gfp_t gfp_mask) { return blkdev_issue_zeroout(sb->s_bdev, - block << (sb->s_blocksize_bits - 9), - nr_blocks << (sb->s_blocksize_bits - 9), + block << (sb->s_blocksize_bits - + SECTOR_SHIFT), + nr_blocks << (sb->s_blocksize_bits - + SECTOR_SHIFT), gfp_mask, 0); } @@ -1492,7 +1511,8 @@ static inline int queue_alignment_offset(struct request_queue *q) 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_div(sector, granularity >> 9) << 9; + unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) + << SECTOR_SHIFT; return (granularity + lim->alignment_offset - alignment) % granularity; } @@ -1526,8 +1546,8 @@ static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector return 0; /* Why are these in bytes, not sectors? */ - alignment = lim->discard_alignment >> 9; - granularity = lim->discard_granularity >> 9; + alignment = lim->discard_alignment >> SECTOR_SHIFT; + granularity = lim->discard_granularity >> SECTOR_SHIFT; if (!granularity) return 0; @@ -1538,7 +1558,7 @@ static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector offset = (granularity + alignment - offset) % granularity; /* Turn it back into bytes, gaah */ - return offset << 9; + return offset << SECTOR_SHIFT; } static inline int bdev_discard_alignment(struct block_device *bdev) |