summaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
Diffstat (limited to 'include')
-rw-r--r--include/linux/blkdev.h42
-rw-r--r--include/linux/device-mapper.h2
-rw-r--r--include/linux/ide.h1
-rw-r--r--include/uapi/linux/msdos_fs.h2
4 files changed, 33 insertions, 14 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 19eaf8d89368..9af3e0f430bc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1022,6 +1022,19 @@ 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
@@ -1048,12 +1061,12 @@ 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;
}
static inline unsigned int blk_rq_zone_no(struct request *rq)
@@ -1083,7 +1096,8 @@ 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;
@@ -1395,16 +1409,21 @@ 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);
}
@@ -1511,7 +1530,8 @@ 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;
}
@@ -1545,8 +1565,8 @@ 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;
@@ -1557,7 +1577,7 @@ 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)
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index da83f64952e7..4384433b50e7 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -542,8 +542,6 @@ do { \
#define DMEMIT(x...) sz += ((sz >= maxlen) ? \
0 : scnprintf(result + sz, maxlen - sz, x))
-#define SECTOR_SHIFT 9
-
/*
* Definitions of return values from target end_io function.
*/
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 771989d25ef8..0acfa62b1d44 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -165,7 +165,6 @@ struct ide_io_ports {
*/
#define PARTN_BITS 6 /* number of minor dev bits for partitions */
#define MAX_DRIVES 2 /* per interface; 2 assumed by lots of code */
-#define SECTOR_SIZE 512
/*
* Timeouts for various operations:
diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h
index a45d0754102e..fde753735aba 100644
--- a/include/uapi/linux/msdos_fs.h
+++ b/include/uapi/linux/msdos_fs.h
@@ -10,7 +10,9 @@
* The MS-DOS filesystem constants/structures
*/
+#ifndef SECTOR_SIZE
#define SECTOR_SIZE 512 /* sector size (bytes) */
+#endif
#define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */
#define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */
#define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */