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block: simplify with PAGE_SECTORS_SHIFT

PATCH Superseded Luis Chamberlain 3 participants 14 messages May 26, 2023

Subsystems (9)
Memory management VFS Block layer s390 +5 more subsystems

v2 of 3 Superseded Latest is v3 →

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Luis Chamberlain

author
#0 lore raw

v2 cover block: simplify with PAGE_SECTORS_SHIFT

A bit of block drivers have their own incantations with PAGE_SHIFT - SECTOR_SHIFT. Just simplfy and use PAGE_SECTORS_SHIFT all over.

Based on linux-next next-20230525.

Changes since v1:

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

Luis Chamberlain (5):
block: annotate bdev_disk_changed() deprecation with a symbol
namespace
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

 block/partitions/core.c          |  6 +-----
 drivers/block/drbd/drbd_bitmap.c |  4 ++--
 drivers/block/loop.c             |  2 ++
 drivers/block/zram/zram_drv.c    | 12 ++++++------
 drivers/block/zram/zram_drv.h    |  2 --
 drivers/md/dm-bufio.c            |  4 ++--
 drivers/s390/block/dasd_genhd.c  |  2 ++
 fs/iomap/buffered-io.c           |  2 +-
 8 files changed, 16 insertions(+), 18 deletions(-)
Signature · 1 line
2.39.2
author
#1 lore raw

PATCH v2 1/5 block: annotate bdev_disk_changed() deprecation with a symbol namespace

This ensures no other users pop up by mistake easily and provides us a with an easy vehicle to do the same with other routines should we need it later.

Signed-off-by Luis Chamberlain <[email protected]>
---
 block/partitions/core.c         | 6 +-----
 drivers/block/loop.c            | 2 ++
 drivers/s390/block/dasd_genhd.c | 2 ++
 3 files changed, 5 insertions(+), 5 deletions(-)
block/partitions/core.c +1 -5
index 49e0496ff23c..6f18444be4fe 100644
@@ -690,11 +690,7 @@ int bdev_disk_changed(struct gendisk *disk, bool invalidate)
 
 	return ret;
 }
-/*
- * Only exported for loop and dasd for historic reasons.  Don't use in new
- * code!
- */
-EXPORT_SYMBOL_GPL(bdev_disk_changed);
+EXPORT_SYMBOL_NS_GPL(bdev_disk_changed, BLOCK_DEPRECATED);
 
 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
 {
drivers/block/loop.c +2 -0
index bc31bb7072a2..50aa5b4c0c56 100644
@@ -37,6 +37,8 @@
 #include <linux/spinlock.h>
 #include <uapi/linux/loop.h>
 
+MODULE_IMPORT_NS(BLOCK_DEPRECATED);
+
 /* Possible states of device */
 enum {
 	Lo_unbound,
drivers/s390/block/dasd_genhd.c +2 -0
index 998a961e1704..5ea244aec534 100644
@@ -25,6 +25,8 @@
 
 #include "dasd_int.h"
 
+MODULE_IMPORT_NS(BLOCK_DEPRECATED);
+
 static unsigned int queue_depth = 32;
 static unsigned int nr_hw_queues = 4;
Signature · 1 line
2.39.2
#2 lore raw

Re: [PATCH v2 1/5] block: annotate bdev_disk_changed() deprecation with a symbol namespace

Quoted 3 lines · Luis Chamberlain

This ensures no other users pop up by mistake easily and provides us a with an easy vehicle to do the same with other routines should we need it later.

I don't see how this is related to the rest of the seris. I also don't think it's a good idea. The APIs isn't deprecated per se. It just should not be called by drivers. The right thing would be an interface like

EXPORT_SYMBOL_GPL_FOR(bdev_disk_changed, loop.ko, CONFIG_BLK_DEV_LOOP); EXPORT_SYMBOL_GPL_FOR(bdev_disk_changed, dasd_mod.ko, CONFIG_DASD);

with the modulo code enforcing that no one but the module this is explicitly exorted for can use the symbol.

author
#3 lore raw

Re: [PATCH v2 1/5] block: annotate bdev_disk_changed() deprecation with a symbol namespace

Quoted 6 lines · Christoph Hellwig
Quoted 3 lines · Luis Chamberlain

This ensures no other users pop up by mistake easily and provides us a with an easy vehicle to do the same with other routines should we need it later.

I don't see how this is related to the rest of the seris.

Jessh, sorry it is too late here and that was a typo that the commit went into the series. I'll go sleep now. This I just had queued as a reminder for the new annotation for deprecated symbols to be used in some situations.

Please ignore this patch.

Luis

author
#4 lore raw

PATCH v2 2/5 drbd: use PAGE_SECTORS_SHIFT and PAGE_SECTORS

In reply to Luis Chamberlain

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

Acked-by Christoph Böhmwalder <[email protected]>
Signed-off-by Luis Chamberlain <[email protected]>
---
 drivers/block/drbd/drbd_bitmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/block/drbd/drbd_bitmap.c +2 -2
index 6ac8c54b44c7..b556e6634f13 100644
@@ -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;
Signature · 1 line
2.39.2
author
#6 lore raw

PATCH v2 3/5 iomap: simplify iomap_init() with PAGE_SECTORS

In reply to Luis Chamberlain

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

Signed-off-by Luis Chamberlain <[email protected]>
---
 fs/iomap/buffered-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/iomap/buffered-io.c +1 -1
index 915b448b8554..5641e696fb3f 100644
@@ -1831,7 +1831,7 @@ 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);
 }
Signature · 1 line
2.39.2
author
#9 lore raw

PATCH v2 4/5 dm bufio: simplify by using PAGE_SECTORS_SHIFT

In reply to 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 <[email protected]>
---
 drivers/md/dm-bufio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/md/dm-bufio.c +2 -2
index eea977662e81..08c4730e1819 100644
@@ -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;

@@ -1190,7 +1190,7 @@ 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:
Signature · 1 line
2.39.2
#10 lore raw

Re: [PATCH v2 4/5] dm bufio: simplify by using PAGE_SECTORS_SHIFT

drivers/md/dm-bufio.c static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,

Quoted 10 lines · Luis Chamberlain
drivers/md/dm-bufio.c +2 -2
 		*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));
 
 
 	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));

The parenthesis are completely unneeded in the new version, please remove them.

author
#11 lore raw

PATCH v2 5/5 zram: use generic PAGE_SECTORS and PAGE_SECTORS_SHIFT

In reply to 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

This produces no functional changes.

Reviewed-by Sergey Senozhatsky <[email protected]>
Signed-off-by Luis Chamberlain <[email protected]>
---
 drivers/block/zram/zram_drv.c | 12 ++++++------
 drivers/block/zram/zram_drv.h |  2 --
 2 files changed, 6 insertions(+), 8 deletions(-)
drivers/block/zram/zram_drv.c +6 -6
index f6d90f1ba5cf..5fdeb78ace9a 100644
@@ -1834,8 +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)) <<
+	u32 index = bio->bi_iter.bi_sector >> PAGE_SECTORS_SHIFT;
+	u32 offset = (bio->bi_iter.bi_sector & (PAGE_SECTORS - 1)) <<
 			SECTOR_SHIFT;
 
 	/*

@@ -1876,8 +1876,8 @@ static void zram_bio_read(struct zram *zram, struct bio *bio)
 
 	start_time = bio_start_io_acct(bio);
 	bio_for_each_segment(bv, bio, iter) {
-		u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
-		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
+		u32 index = iter.bi_sector >> PAGE_SECTORS_SHIFT;
+		u32 offset = (iter.bi_sector & (PAGE_SECTORS - 1)) <<
 				SECTOR_SHIFT;
 
 		if (zram_bvec_read(zram, &bv, index, offset, bio) < 0) {

@@ -1903,8 +1903,8 @@ static void zram_bio_write(struct zram *zram, struct bio *bio)
 
 	start_time = bio_start_io_acct(bio);
 	bio_for_each_segment(bv, bio, iter) {
-		u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
-		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
+		u32 index = iter.bi_sector >> PAGE_SECTORS_SHIFT;
+		u32 offset = (iter.bi_sector & (PAGE_SECTORS - 1)) <<
 				SECTOR_SHIFT;
 
 		if (zram_bvec_write(zram, &bv, index, offset, bio) < 0) {
drivers/block/zram/zram_drv.h +0 -2
index ca7a15bd4845..9f2543af5c76 100644
@@ -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	\
Signature · 1 line
2.39.2
#12 lore raw

Re: [PATCH v2 5/5] zram: use generic PAGE_SECTORS and PAGE_SECTORS_SHIFT

drivers/block/zram/zram_drv.c static ssize_t recompress_store(struct device *dev, · line 1839

Quoted 3 lines · Luis Chamberlain
drivers/block/zram/zram_drv.c +2 -0
+	u32 index = bio->bi_iter.bi_sector >> PAGE_SECTORS_SHIFT;
+	u32 offset = (bio->bi_iter.bi_sector & (PAGE_SECTORS - 1)) <<
 			SECTOR_SHIFT;

(PAGE_SECTORS - 1) is SECTOR_MASK, please use this.

Thanks,
Johannes

#13 lore raw
In reply to Luis Chamberlain
Quoted 20 lines · Luis Chamberlain

A bit of block drivers have their own incantations with PAGE_SHIFT - SECTOR_SHIFT. Just simplfy and use PAGE_SECTORS_SHIFT all over.

Based on linux-next next-20230525.

Changes since v1:

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

Luis Chamberlain (5):
block: annotate bdev_disk_changed() deprecation with a symbol
namespace
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

Quoted 10 lines
 block/partitions/core.c          |  6 +-----
 drivers/block/drbd/drbd_bitmap.c |  4 ++--
 drivers/block/loop.c             |  2 ++
 drivers/block/zram/zram_drv.c    | 12 ++++++------
 drivers/block/zram/zram_drv.h    |  2 --
 drivers/md/dm-bufio.c            |  4 ++--
 drivers/s390/block/dasd_genhd.c  |  2 ++
 fs/iomap/buffered-io.c           |  2 +-
 8 files changed, 16 insertions(+), 18 deletions(-)

Hey Luis,
I've found another one in sd_zbc_revalidate_zones():

	max_append = min_t(u32, logical_to_sectors(sdkp->device, zone_blocks),
			   q->limits.max_segments << (PAGE_SHIFT - 9));

Mind taking care of it in the next round as well?

Thanks,
Johannes