provide a sane discard_granularity default

provide a sane discard_granularity default

[Christoph Hellwig]

Hi Jens,

this series defaults the discard_granularity to the sector size as
that is a very logical default for devices that have no further
restrictions.  This removes the need for trivial drivers to set
a discard granularity and cleans up the interface.

Diffstat:
 arch/um/drivers/ubd_kern.c    |    1 -
 block/blk-merge.c             |    6 +-----
 block/blk-settings.c          |    5 ++++-
 drivers/block/nbd.c           |    6 +-----
 drivers/block/null_blk/main.c |    1 -
 drivers/block/zram/zram_drv.c |    1 -
 drivers/md/bcache/super.c     |    1 -
 drivers/mtd/mtd_blkdevs.c     |    4 +---
 8 files changed, 7 insertions(+), 18 deletions(-)

[PATCH 1/9] block: remove two comments in bio_split_discard

[Christoph Hellwig]

A zero discard_granularity is not treated the same as a single-block one,
and not having any segments after taking alignment is perfectly fine
and does not need a warning.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-merge.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 65e75efa9bd366..2d470cf2173e29 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -115,17 +115,13 @@ static struct bio *bio_split_discard(struct bio *bio,
 
 	*nsegs = 1;
 
-	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(lim->discard_granularity >> 9, 1U);
 
 	max_discard_sectors =
 		min(lim->max_discard_sectors, bio_allowed_max_sectors(lim));
 	max_discard_sectors -= max_discard_sectors % granularity;
-
-	if (unlikely(!max_discard_sectors)) {
-		/* XXX: warn */
+	if (unlikely(!max_discard_sectors))
 		return NULL;
-	}
 
 	if (bio_sectors(bio) <= max_discard_sectors)
 		return NULL;
-- 
2.39.2

[PATCH 2/9] bcache: discard_granularity should not be smaller than a sector

[Christoph Hellwig]

Just like all block I/O, discards are in units of sectors.  Thus setting a
smaller than sector size discard limit in case of > 512 byte sectors in
bcache doesn't make sense.  Always set the discard granularity to 512
bytes instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/bcache/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index bfe1685dbae574..ecc1447f202a42 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -954,7 +954,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 	q->limits.max_segment_size	= UINT_MAX;
 	q->limits.max_segments		= BIO_MAX_VECS;
 	blk_queue_max_discard_sectors(q, UINT_MAX);
-	q->limits.discard_granularity	= 512;
+	q->limits.discard_granularity	= block_size;
 	q->limits.io_min		= block_size;
 	q->limits.logical_block_size	= block_size;
 	q->limits.physical_block_size	= block_size;
-- 
2.39.2

[PATCH 3/9] block: default the discard granularity to sector size

[Christoph Hellwig]

Current the discard granularity defaults to 0 and must be initialized by
any driver that wants to support discard.  Default to the sector size
instead, which is the smallest possible value, and a very useful default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-settings.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index ba6e0e97118c08..d993d20dab3c6d 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -48,7 +48,7 @@ void blk_set_default_limits(struct queue_limits *lim)
 	lim->max_discard_sectors = 0;
 	lim->max_hw_discard_sectors = 0;
 	lim->max_secure_erase_sectors = 0;
-	lim->discard_granularity = 0;
+	lim->discard_granularity = 512;
 	lim->discard_alignment = 0;
 	lim->discard_misaligned = 0;
 	lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
@@ -309,6 +309,9 @@ void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
 
 	limits->logical_block_size = size;
 
+	if (limits->discard_granularity < limits->logical_block_size)
+		limits->discard_granularity = limits->logical_block_size;
+
 	if (limits->physical_block_size < size)
 		limits->physical_block_size = size;
 
-- 
2.39.2

[PATCH 4/9] ubd: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/um/drivers/ubd_kern.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 50206feac577d5..92ee2697ff3984 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -798,7 +798,6 @@ static int ubd_open_dev(struct ubd *ubd_dev)
 		ubd_dev->cow.fd = err;
 	}
 	if (ubd_dev->no_trim == 0) {
-		ubd_dev->queue->limits.discard_granularity = SECTOR_SIZE;
 		blk_queue_max_discard_sectors(ubd_dev->queue, UBD_MAX_REQUEST);
 		blk_queue_max_write_zeroes_sectors(ubd_dev->queue, UBD_MAX_REQUEST);
 	}
-- 
2.39.2

[PATCH 5/9] nbd: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.  Also don't bother clearing it as a discard
granularity without discard_sectors doesn't mean anything.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/nbd.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b6414e1e645b76..4e72ec4e25ac5a 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -334,10 +334,8 @@ static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize,
 	if (!nbd->pid)
 		return 0;
 
-	if (nbd->config->flags & NBD_FLAG_SEND_TRIM) {
-		nbd->disk->queue->limits.discard_granularity = blksize;
+	if (nbd->config->flags & NBD_FLAG_SEND_TRIM)
 		blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
-	}
 	blk_queue_logical_block_size(nbd->disk->queue, blksize);
 	blk_queue_physical_block_size(nbd->disk->queue, blksize);
 
@@ -1357,7 +1355,6 @@ static void nbd_config_put(struct nbd_device *nbd)
 		nbd->config = NULL;
 
 		nbd->tag_set.timeout = 0;
-		nbd->disk->queue->limits.discard_granularity = 0;
 		blk_queue_max_discard_sectors(nbd->disk->queue, 0);
 
 		mutex_unlock(&nbd->config_lock);
@@ -1850,7 +1847,6 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
 	 * Tell the block layer that we are not a rotational device
 	 */
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
-	disk->queue->limits.discard_granularity = 0;
 	blk_queue_max_discard_sectors(disk->queue, 0);
 	blk_queue_max_segment_size(disk->queue, UINT_MAX);
 	blk_queue_max_segments(disk->queue, USHRT_MAX);
-- 
2.39.2

[PATCH 6/9] null_blk: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/null_blk/main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 13ed446b5e198e..9f7695f00c2db8 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1880,7 +1880,6 @@ static void null_config_discard(struct nullb *nullb)
 		return;
 	}
 
-	nullb->q->limits.discard_granularity = nullb->dev->blocksize;
 	blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);
 }
 
-- 
2.39.2

[PATCH 7/9] zram: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/zram/zram_drv.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d77d3664ca0805..e1dec0483a012b 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2227,7 +2227,6 @@ static int zram_add(void)
 					ZRAM_LOGICAL_BLOCK_SIZE);
 	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
 	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
-	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;
 	blk_queue_max_discard_sectors(zram->disk->queue, UINT_MAX);
 
 	/*
-- 
2.39.2

[PATCH 8/9] bcache: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/bcache/super.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index ecc1447f202a42..39ec95b8613f1f 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -954,7 +954,6 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 	q->limits.max_segment_size	= UINT_MAX;
 	q->limits.max_segments		= BIO_MAX_VECS;
 	blk_queue_max_discard_sectors(q, UINT_MAX);
-	q->limits.discard_granularity	= block_size;
 	q->limits.io_min		= block_size;
 	q->limits.logical_block_size	= block_size;
 	q->limits.physical_block_size	= block_size;
-- 
2.39.2

[PATCH 9/9] mtd_blkdevs: use the default discard granularity

[Christoph Hellwig]

The discard granularity now defaults to a single sector, so don't set
that value explicitly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/mtd/mtd_blkdevs.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index ff18636e088973..0da7b33849471a 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -376,10 +376,8 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
 
-	if (tr->discard) {
+	if (tr->discard)
 		blk_queue_max_discard_sectors(new->rq, UINT_MAX);
-		new->rq->limits.discard_granularity = tr->blksize;
-	}
 
 	gd->queue = new->rq;
 
-- 
2.39.2

Re: [PATCH 9/9] mtd_blkdevs: use the default discard granularity

[Richard Weinberger]

----- Ursprüngliche Mail -----
> Von: "hch" <hch@lst.de>
> An: "Jens Axboe" <axboe@kernel.dk>
> CC: "richard" <richard@nod.at>, "anton ivanov" <anton.ivanov@cambridgegreys.com>, "Josef Bacik" <josef@toxicpanda.com>,
> "Minchan Kim" <minchan@kernel.org>, "senozhatsky" <senozhatsky@chromium.org>, "Coly Li" <colyli@suse.de>, "Miquel
> Raynal" <miquel.raynal@bootlin.com>, "Vignesh Raghavendra" <vigneshr@ti.com>, "linux-um"
> <linux-um@lists.infradead.org>, "linux-block" <linux-block@vger.kernel.org>, nbd@other.debian.org, "linux-bcache"
> <linux-bcache@vger.kernel.org>, "linux-mtd" <linux-mtd@lists.infradead.org>
> Gesendet: Donnerstag, 28. Dezember 2023 08:55:45
> Betreff: [PATCH 9/9] mtd_blkdevs: use the default discard granularity

> The discard granularity now defaults to a single sector, so don't set
> that value explicitly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/mtd/mtd_blkdevs.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
> index ff18636e088973..0da7b33849471a 100644
> --- a/drivers/mtd/mtd_blkdevs.c
> +++ b/drivers/mtd/mtd_blkdevs.c
> @@ -376,10 +376,8 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
> 	blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
> 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
> 
> -	if (tr->discard) {
> +	if (tr->discard)
> 		blk_queue_max_discard_sectors(new->rq, UINT_MAX);
> -		new->rq->limits.discard_granularity = tr->blksize;
> -	}

Acked-by: Richard Weinberger <richard@nod.at>

Thanks,
//richard

Re: [PATCH 4/9] ubd: use the default discard granularity

[Richard Weinberger]

----- Ursprüngliche Mail -----
> Von: "hch" <hch@lst.de>
> An: "Jens Axboe" <axboe@kernel.dk>
> CC: "richard" <richard@nod.at>, "anton ivanov" <anton.ivanov@cambridgegreys.com>, "Josef Bacik" <josef@toxicpanda.com>,
> "Minchan Kim" <minchan@kernel.org>, "senozhatsky" <senozhatsky@chromium.org>, "Coly Li" <colyli@suse.de>, "Miquel
> Raynal" <miquel.raynal@bootlin.com>, "Vignesh Raghavendra" <vigneshr@ti.com>, "linux-um"
> <linux-um@lists.infradead.org>, "linux-block" <linux-block@vger.kernel.org>, nbd@other.debian.org, "linux-bcache"
> <linux-bcache@vger.kernel.org>, "linux-mtd" <linux-mtd@lists.infradead.org>
> Gesendet: Donnerstag, 28. Dezember 2023 08:55:40
> Betreff: [PATCH 4/9] ubd: use the default discard granularity

> The discard granularity now defaults to a single sector, so don't set
> that value explicitly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> arch/um/drivers/ubd_kern.c | 1 -
> 1 file changed, 1 deletion(-)
> 
> diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
> index 50206feac577d5..92ee2697ff3984 100644
> --- a/arch/um/drivers/ubd_kern.c
> +++ b/arch/um/drivers/ubd_kern.c
> @@ -798,7 +798,6 @@ static int ubd_open_dev(struct ubd *ubd_dev)
> 		ubd_dev->cow.fd = err;
> 	}
> 	if (ubd_dev->no_trim == 0) {
> -		ubd_dev->queue->limits.discard_granularity = SECTOR_SIZE;
> 		blk_queue_max_discard_sectors(ubd_dev->queue, UBD_MAX_REQUEST);
> 		blk_queue_max_write_zeroes_sectors(ubd_dev->queue, UBD_MAX_REQUEST);
> 	}

Acked-by: Richard Weinberger <richard@nod.at>

Thanks,
//richard

Re: provide a sane discard_granularity default

[Jens Axboe]

On Thu, 28 Dec 2023 07:55:36 +0000, Christoph Hellwig wrote:
> this series defaults the discard_granularity to the sector size as
> that is a very logical default for devices that have no further
> restrictions.  This removes the need for trivial drivers to set
> a discard granularity and cleans up the interface.
> 
> Diffstat:
>  arch/um/drivers/ubd_kern.c    |    1 -
>  block/blk-merge.c             |    6 +-----
>  block/blk-settings.c          |    5 ++++-
>  drivers/block/nbd.c           |    6 +-----
>  drivers/block/null_blk/main.c |    1 -
>  drivers/block/zram/zram_drv.c |    1 -
>  drivers/md/bcache/super.c     |    1 -
>  drivers/mtd/mtd_blkdevs.c     |    4 +---
>  8 files changed, 7 insertions(+), 18 deletions(-)
> 
> [...]

Applied, thanks!

[1/9] block: remove two comments in bio_split_discard
      commit: 928a5dd3a849dc6d8298835bdcb25c360d41bccb
[2/9] bcache: discard_granularity should not be smaller than a sector
      commit: 5e7169e7f7c0989304dbe8467a1d703d614c64db
[3/9] block: default the discard granularity to sector size
      commit: 3c407dc723bbf914f3744b0c2bb82265b411a50c
[4/9] ubd: use the default discard granularity
      commit: 599d9d4eab7c3d5dc6f1e0f8f052fee9eaa54e50
[5/9] nbd: use the default discard granularity
      commit: 1e2ab2e8a98c9e0629b5b8bff8ee6f2cb3e8daac
[6/9] null_blk: use the default discard granularity
      commit: 724325477f8a48ce1defc2a49998bbc19fe85c88
[7/9] zram: use the default discard granularity
      commit: 3753039def5d0d1c43af847b507ba9b782db183a
[8/9] bcache: use the default discard granularity
      commit: 105c1a5f6ccef7f52f9e76664407ef96218272eb
[9/9] mtd_blkdevs: use the default discard granularity
      commit: 31e4fac930814f2f92eb6ebac9c4d4e3b09f7aaf

Best regards,
-- 
Jens Axboe

Re: [PATCH 7/9] zram: use the default discard granularity

[Sergey Senozhatsky]

On (23/12/28 07:55), Christoph Hellwig wrote:
> 
> The discard granularity now defaults to a single sector, so don't set
> that value explicitly

Hmm, but sector size != PAGE_SIZE

[..]

> @@ -2227,7 +2227,6 @@ static int zram_add(void)
>  					ZRAM_LOGICAL_BLOCK_SIZE);
>  	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
>  	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
> -	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;

Re: [PATCH 7/9] zram: use the default discard granularity

[Jens Axboe]

On 1/1/24 6:15 PM, Sergey Senozhatsky wrote:
> On (23/12/28 07:55), Christoph Hellwig wrote:
>>
>> The discard granularity now defaults to a single sector, so don't set
>> that value explicitly
> 
> Hmm, but sector size != PAGE_SIZE
> 
> [..]
> 
>> @@ -2227,7 +2227,6 @@ static int zram_add(void)
>>  					ZRAM_LOGICAL_BLOCK_SIZE);
>>  	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
>>  	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
>> -	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;

Yep, that does indeed look buggy.

-- 
Jens Axboe

Re: [PATCH 7/9] zram: use the default discard granularity

[Jens Axboe]

On 1/2/24 8:40 AM, Jens Axboe wrote:
> On 1/1/24 6:15 PM, Sergey Senozhatsky wrote:
>> On (23/12/28 07:55), Christoph Hellwig wrote:
>>>
>>> The discard granularity now defaults to a single sector, so don't set
>>> that value explicitly
>>
>> Hmm, but sector size != PAGE_SIZE
>>
>> [..]
>>
>>> @@ -2227,7 +2227,6 @@ static int zram_add(void)
>>>  					ZRAM_LOGICAL_BLOCK_SIZE);
>>>  	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
>>>  	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
>>> -	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;
> 
> Yep, that does indeed look buggy.

Ah no it's fine, it'll default to the sector size of the device, which
is set before the discard limit/granularity. So should work fine as-is.

-- 
Jens Axboe

Re: [PATCH 7/9] zram: use the default discard granularity

[Jens Axboe]

On 1/2/24 8:44 AM, Jens Axboe wrote:
> On 1/2/24 8:40 AM, Jens Axboe wrote:
>> On 1/1/24 6:15 PM, Sergey Senozhatsky wrote:
>>> On (23/12/28 07:55), Christoph Hellwig wrote:
>>>>
>>>> The discard granularity now defaults to a single sector, so don't set
>>>> that value explicitly
>>>
>>> Hmm, but sector size != PAGE_SIZE
>>>
>>> [..]
>>>
>>>> @@ -2227,7 +2227,6 @@ static int zram_add(void)
>>>>  					ZRAM_LOGICAL_BLOCK_SIZE);
>>>>  	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
>>>>  	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
>>>> -	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;
>>
>> Yep, that does indeed look buggy.
> 
> Ah no it's fine, it'll default to the sector size of the device, which
> is set before the discard limit/granularity. So should work fine as-is.

Replying to myself again... It does then default it to the logical block
size, not the physical one. Which does look odd, seems like that should
be the physical size?

In any case, this does change behavior for zram.

Christoph?

-- 
Jens Axboe

Re: [PATCH 3/9] block: default the discard granularity to sector size

[John Pittman]

Hi Christoph, is there a reason you used 512 instead of SECTOR_SIZE
from include/linux/blk_types.h?  Thanks!

On Thu, Dec 28, 2023 at 2:56 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Current the discard granularity defaults to 0 and must be initialized by
> any driver that wants to support discard.  Default to the sector size
> instead, which is the smallest possible value, and a very useful default.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-settings.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index ba6e0e97118c08..d993d20dab3c6d 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -48,7 +48,7 @@ void blk_set_default_limits(struct queue_limits *lim)
>         lim->max_discard_sectors = 0;
>         lim->max_hw_discard_sectors = 0;
>         lim->max_secure_erase_sectors = 0;
> -       lim->discard_granularity = 0;
> +       lim->discard_granularity = 512;
>         lim->discard_alignment = 0;
>         lim->discard_misaligned = 0;
>         lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
> @@ -309,6 +309,9 @@ void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
>
>         limits->logical_block_size = size;
>
> +       if (limits->discard_granularity < limits->logical_block_size)
> +               limits->discard_granularity = limits->logical_block_size;
> +
>         if (limits->physical_block_size < size)
>                 limits->physical_block_size = size;
>
> --
> 2.39.2
>
>

Re: [PATCH 3/9] block: default the discard granularity to sector size

[Christoph Hellwig]

On Tue, Jan 02, 2024 at 05:11:19PM -0500, John Pittman wrote:
> Hi Christoph, is there a reason you used 512 instead of SECTOR_SIZE
> from include/linux/blk_types.h?  Thanks!

To match the logical_block_size/physical_block_size/io_min
assignments just below.

Re: [PATCH 8/9] bcache: use the default discard granularity

[Coly Li]

On Thu, Dec 28, 2023 at 07:55:44AM +0000, Christoph Hellwig wrote:
> The discard granularity now defaults to a single sector, so don't set
> that value explicitly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Coly Li <colyli@suse.de>

Thanks.

> ---
>  drivers/md/bcache/super.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index ecc1447f202a42..39ec95b8613f1f 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -954,7 +954,6 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
>  	q->limits.max_segment_size	= UINT_MAX;
>  	q->limits.max_segments		= BIO_MAX_VECS;
>  	blk_queue_max_discard_sectors(q, UINT_MAX);
> -	q->limits.discard_granularity	= block_size;
>  	q->limits.io_min		= block_size;
>  	q->limits.logical_block_size	= block_size;
>  	q->limits.physical_block_size	= block_size;
> -- 
> 2.39.2
> 
> 

-- 
Coly Li

Re: [PATCH 7/9] zram: use the default discard granularity

[Sergey Senozhatsky]

On (23/12/28 07:55), Christoph Hellwig wrote:
> 
> The discard granularity now defaults to a single sector, so don't set
> that value explicitly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

FWIW,
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>