[PATCH v3 0/4] block: simplify with PAGE_SECTORS_SHIFT

[PATCH v3 0/4] block: simplify with PAGE_SECTORS_SHIFT

[Luis Chamberlain]

Just spinning these low hanging fruit patches I forgot about.

Changes on v3:

 o Add tags for Reviews/acks
 o rebase onto next-20230914
 o Fixes as suggested by Johannes Thumshirn:
   - drop not-needed parens on dm bufio
   - use SECTOR_MASK instead of PAGE_SECTORS - 1 for the zram driver
 o Drop shmem patches as they are already merged / modified

Changes on v2:
                                                                                                                                                                                              
 o keep iomap math visibly simple                                                                                                                                                             
 o Add tags for Reviews/acks                                                                                                                                                                  
 o rebase onto next-20230525 

Luis Chamberlain (4):
  drbd: use PAGE_SECTORS_SHIFT and PAGE_SECTORS
  iomap: simplify iomap_init() with PAGE_SECTORS
  dm bufio: simplify by using PAGE_SECTORS_SHIFT
  zram: use generic PAGE_SECTORS and PAGE_SECTORS_SHIFT

 drivers/block/drbd/drbd_bitmap.c |  4 ++--
 drivers/block/zram/zram_drv.c    | 15 ++++++---------
 drivers/block/zram/zram_drv.h    |  2 --
 drivers/md/dm-bufio.c            |  4 ++--
 fs/iomap/buffered-io.c           |  2 +-
 5 files changed, 11 insertions(+), 16 deletions(-)

-- 
2.39.2

[PATCH v3 1/4] drbd: use PAGE_SECTORS_SHIFT and PAGE_SECTORS

[Luis Chamberlain]

Replace common constants with generic versions.
This produces no functional changes.

Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 drivers/block/drbd/drbd_bitmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 85ca000a0564..1a1782f55e61 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1000,7 +1000,7 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho
 	unsigned int len;
 
 	first_bm_sect = device->ldev->md.md_offset + device->ldev->md.bm_offset;
-	on_disk_sector = first_bm_sect + (((sector_t)page_nr) << (PAGE_SHIFT-SECTOR_SHIFT));
+	on_disk_sector = first_bm_sect + (((sector_t)page_nr) << PAGE_SECTORS_SHIFT);
 
 	/* this might happen with very small
 	 * flexible external meta data device,
@@ -1008,7 +1008,7 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho
 	last_bm_sect = drbd_md_last_bitmap_sector(device->ldev);
 	if (first_bm_sect <= on_disk_sector && last_bm_sect >= on_disk_sector) {
 		sector_t len_sect = last_bm_sect - on_disk_sector + 1;
-		if (len_sect < PAGE_SIZE/SECTOR_SIZE)
+		if (len_sect < PAGE_SECTORS)
 			len = (unsigned int)len_sect*SECTOR_SIZE;
 		else
 			len = PAGE_SIZE;
-- 
2.39.2

[PATCH v3 2/4] iomap: simplify iomap_init() with PAGE_SECTORS

[Luis Chamberlain]

Replace common constants with generic versions. This produces no
functional changes.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/iomap/buffered-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index ae8673ce08b1..1a16c0e5d190 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1985,7 +1985,7 @@ EXPORT_SYMBOL_GPL(iomap_writepages);
 
 static int __init iomap_init(void)
 {
-	return bioset_init(&iomap_ioend_bioset, 4 * (PAGE_SIZE / SECTOR_SIZE),
+	return bioset_init(&iomap_ioend_bioset, 4 * PAGE_SECTORS,
 			   offsetof(struct iomap_ioend, io_inline_bio),
 			   BIOSET_NEED_BVECS);
 }
-- 
2.39.2

[PATCH v3 3/4] dm bufio: simplify by using PAGE_SECTORS_SHIFT

[Luis Chamberlain]

The PAGE_SHIFT - SECTOR_SHIFT constant be replaced with PAGE_SECTORS_SHIFT
defined in linux/blt_types.h, which is included by linux/blkdev.h.

This produces no functional changes.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 drivers/md/dm-bufio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 62eb27639c9b..a5b48be93b30 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1152,7 +1152,7 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
 	    gfp_mask & __GFP_NORETRY) {
 		*data_mode = DATA_MODE_GET_FREE_PAGES;
 		return (void *)__get_free_pages(gfp_mask,
-						c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT));
+						c->sectors_per_block_bits - PAGE_SECTORS_SHIFT);
 	}
 
 	*data_mode = DATA_MODE_VMALLOC;
@@ -1173,7 +1173,7 @@ static void free_buffer_data(struct dm_bufio_client *c,
 
 	case DATA_MODE_GET_FREE_PAGES:
 		free_pages((unsigned long)data,
-			   c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT));
+			   c->sectors_per_block_bits - PAGE_SECTORS_SHIFT);
 		break;
 
 	case DATA_MODE_VMALLOC:
-- 
2.39.2

[PATCH v3 4/4] zram: use generic PAGE_SECTORS and PAGE_SECTORS_SHIFT

[Luis Chamberlain]

Instead of re-defining the already existing constants use the provided ones:

So replace:

 o SECTORS_PER_PAGE_SHIFT with PAGE_SECTORS_SHIFT
 o SECTORS_PER_PAGE       with PAGE_SECTORS
 o SECTORS_PER_PAGE - 1   with SECTOR_MASK

This produces no functional changes.

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 drivers/block/zram/zram_drv.c | 15 ++++++---------
 drivers/block/zram/zram_drv.h |  2 --
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 06673c6ca255..58d36c8574d4 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1834,9 +1834,8 @@ static ssize_t recompress_store(struct device *dev,
 static void zram_bio_discard(struct zram *zram, struct bio *bio)
 {
 	size_t n = bio->bi_iter.bi_size;
-	u32 index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
-	u32 offset = (bio->bi_iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
-			SECTOR_SHIFT;
+	u32 index = bio->bi_iter.bi_sector >> PAGE_SECTORS_SHIFT;
+	u32 offset = (bio->bi_iter.bi_sector & SECTOR_MASK) << SECTOR_SHIFT;
 
 	/*
 	 * zram manages data in physical block size units. Because logical block
@@ -1874,9 +1873,8 @@ static void zram_bio_read(struct zram *zram, struct bio *bio)
 	struct bvec_iter iter = bio->bi_iter;
 
 	do {
-		u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
-		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
-				SECTOR_SHIFT;
+		u32 index = iter.bi_sector >> PAGE_SECTORS_SHIFT;
+		u32 offset = (iter.bi_sector & SECTOR_MASK) << SECTOR_SHIFT;
 		struct bio_vec bv = bio_iter_iovec(bio, iter);
 
 		bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset);
@@ -1905,9 +1903,8 @@ static void zram_bio_write(struct zram *zram, struct bio *bio)
 	struct bvec_iter iter = bio->bi_iter;
 
 	do {
-		u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
-		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
-				SECTOR_SHIFT;
+		u32 index = iter.bi_sector >> PAGE_SECTORS_SHIFT;
+		u32 offset = (iter.bi_sector & SECTOR_MASK) << SECTOR_SHIFT;
 		struct bio_vec bv = bio_iter_iovec(bio, iter);
 
 		bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset);
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index ca7a15bd4845..9f2543af5c76 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -21,8 +21,6 @@
 
 #include "zcomp.h"
 
-#define SECTORS_PER_PAGE_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
-#define SECTORS_PER_PAGE	(1 << SECTORS_PER_PAGE_SHIFT)
 #define ZRAM_LOGICAL_BLOCK_SHIFT 12
 #define ZRAM_LOGICAL_BLOCK_SIZE	(1 << ZRAM_LOGICAL_BLOCK_SHIFT)
 #define ZRAM_SECTOR_PER_LOGICAL_BLOCK	\
-- 
2.39.2

Re: [PATCH v3 2/4] iomap: simplify iomap_init() with PAGE_SECTORS

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: [PATCH v3 3/4] dm bufio: simplify by using PAGE_SECTORS_SHIFT

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: [PATCH v3 4/4] zram: use generic PAGE_SECTORS and PAGE_SECTORS_SHIFT

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>