block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>

It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
<linux/blkdev.h> header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
<linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller <davem@davemloft.net>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 0 insertions, 13 deletions

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index deea78e485da..66cb0f857f64 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -24,7 +24,6 @@
 
 #include <linux/uaccess.h>
 
-#define SECTOR_SHIFT		9
 #define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)
 
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 0517613afccb..a76553293a31 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -16,10 +16,8 @@
 #include <linux/badblocks.h>
 #include <linux/fault-inject.h>
 
-#define SECTOR_SHIFT		9
 #define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)
-#define SECTOR_SIZE		(1 << SECTOR_SHIFT)
 #define SECTOR_MASK		(PAGE_SECTORS - 1)
 
 #define FREE_BATCH		16
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 0016170cde0a..1e03b04819c8 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -51,15 +51,6 @@
 #define RBD_DEBUG	/* Activate rbd_assert() calls */
 
 /*
- * The basic unit of block I/O is a sector.  It is interpreted in a
- * number of contexts in Linux (blk, bio, genhd), but the default is
- * universally 512 bytes.  These symbols are just slightly more
- * meaningful than the bare numbers they represent.
- */
-#define	SECTOR_SHIFT	9
-#define	SECTOR_SIZE	(1ULL << SECTOR_SHIFT)
-
-/*
  * Increment the given counter and return its updated value.
  * If the counter is already 0 it will not be incremented.
  * If the counter is already at its maximum value returns
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 31762db861e3..1e9bf65c0bfb 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -37,7 +37,6 @@ static const size_t max_zpage_size = PAGE_SIZE / 4 * 3;
 
 /*-- End of configurable params */
 
-#define SECTOR_SHIFT		9
 #define SECTORS_PER_PAGE_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define SECTORS_PER_PAGE	(1 << SECTORS_PER_PAGE_SHIFT)
 #define ZRAM_LOGICAL_BLOCK_SHIFT 12