linux-f2fs-devel.lists.sourceforge.net archive mirror
 help / color / mirror / Atom feed
* [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
@ 2025-10-24 14:37 Yongpeng Yang
  2025-10-27  8:35 ` Chao Yu via Linux-f2fs-devel
  2025-10-29  9:42 ` Chao Yu via Linux-f2fs-devel
  0 siblings, 2 replies; 6+ messages in thread
From: Yongpeng Yang @ 2025-10-24 14:37 UTC (permalink / raw)
  To: Chao Yu, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

From: Yongpeng Yang <yangyongpeng@xiaomi.com>

When F2FS uses multiple block devices, each device may have a
different discard granularity. The minimum trim granularity must be
at least the maximum discard granularity of all devices, excluding
zoned devices. Use max_t instead of the max() macro to compute the
maximum value.

Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
---
 fs/f2fs/f2fs.h | 12 ++++++++++++
 fs/f2fs/file.c | 12 ++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 32fb2e7338b7..064bdbf463f7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4762,6 +4762,18 @@ static inline bool f2fs_hw_support_discard(struct f2fs_sb_info *sbi)
 	return false;
 }
 
+static inline unsigned int f2fs_hw_discard_granularity(struct f2fs_sb_info *sbi)
+{
+	int i = 1;
+	unsigned int discard_granularity = bdev_discard_granularity(sbi->sb->s_bdev);
+
+	if (f2fs_is_multi_device(sbi))
+		for (; i < sbi->s_ndevs && !bdev_is_zoned(FDEV(i).bdev); i++)
+			discard_granularity = max_t(unsigned int, discard_granularity,
+						bdev_discard_granularity(FDEV(i).bdev));
+	return discard_granularity;
+}
+
 static inline bool f2fs_realtime_discard_enable(struct f2fs_sb_info *sbi)
 {
 	return (test_opt(sbi, DISCARD) && f2fs_hw_support_discard(sbi)) ||
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6d42e2d28861..ced0f78532c9 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2588,14 +2588,14 @@ static int f2fs_keep_noreuse_range(struct inode *inode,
 static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
-	struct super_block *sb = inode->i_sb;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct fstrim_range range;
 	int ret;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!f2fs_hw_support_discard(F2FS_SB(sb)))
+	if (!f2fs_hw_support_discard(sbi))
 		return -EOPNOTSUPP;
 
 	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
@@ -2606,9 +2606,9 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
 	if (ret)
 		return ret;
 
-	range.minlen = max((unsigned int)range.minlen,
-			   bdev_discard_granularity(sb->s_bdev));
-	ret = f2fs_trim_fs(F2FS_SB(sb), &range);
+	range.minlen = max_t(unsigned int, range.minlen,
+			f2fs_hw_discard_granularity(sbi));
+	ret = f2fs_trim_fs(sbi, &range);
 	mnt_drop_write_file(filp);
 	if (ret < 0)
 		return ret;
@@ -2616,7 +2616,7 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
 	if (copy_to_user((struct fstrim_range __user *)arg, &range,
 				sizeof(range)))
 		return -EFAULT;
-	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	f2fs_update_time(sbi, REQ_TIME);
 	return 0;
 }
 
-- 
2.43.0



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
  2025-10-24 14:37 [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices Yongpeng Yang
@ 2025-10-27  8:35 ` Chao Yu via Linux-f2fs-devel
  2025-10-27 13:06   ` Yongpeng Yang
  2025-10-29  9:42 ` Chao Yu via Linux-f2fs-devel
  1 sibling, 1 reply; 6+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2025-10-27  8:35 UTC (permalink / raw)
  To: Yongpeng Yang, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

On 10/24/25 22:37, Yongpeng Yang wrote:
> From: Yongpeng Yang <yangyongpeng@xiaomi.com>
> 
> When F2FS uses multiple block devices, each device may have a
> different discard granularity. The minimum trim granularity must be
> at least the maximum discard granularity of all devices, excluding
> zoned devices. Use max_t instead of the max() macro to compute the
> maximum value.
> 
> Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
> ---
>  fs/f2fs/f2fs.h | 12 ++++++++++++
>  fs/f2fs/file.c | 12 ++++++------
>  2 files changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 32fb2e7338b7..064bdbf463f7 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -4762,6 +4762,18 @@ static inline bool f2fs_hw_support_discard(struct f2fs_sb_info *sbi)
>  	return false;
>  }
>  
> +static inline unsigned int f2fs_hw_discard_granularity(struct f2fs_sb_info *sbi)
> +{
> +	int i = 1;
> +	unsigned int discard_granularity = bdev_discard_granularity(sbi->sb->s_bdev);

Yongpeng,

The patch makes sense to me.

One extra question, if a zoned device contains both conventional zones and
sequential zones, what discard granularity will it exposes?

Thanks,

> +
> +	if (f2fs_is_multi_device(sbi))
> +		for (; i < sbi->s_ndevs && !bdev_is_zoned(FDEV(i).bdev); i++)
> +			discard_granularity = max_t(unsigned int, discard_granularity,
> +						bdev_discard_granularity(FDEV(i).bdev));
> +	return discard_granularity;
> +}
> +
>  static inline bool f2fs_realtime_discard_enable(struct f2fs_sb_info *sbi)
>  {
>  	return (test_opt(sbi, DISCARD) && f2fs_hw_support_discard(sbi)) ||
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 6d42e2d28861..ced0f78532c9 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2588,14 +2588,14 @@ static int f2fs_keep_noreuse_range(struct inode *inode,
>  static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>  {
>  	struct inode *inode = file_inode(filp);
> -	struct super_block *sb = inode->i_sb;
> +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>  	struct fstrim_range range;
>  	int ret;
>  
>  	if (!capable(CAP_SYS_ADMIN))
>  		return -EPERM;
>  
> -	if (!f2fs_hw_support_discard(F2FS_SB(sb)))
> +	if (!f2fs_hw_support_discard(sbi))
>  		return -EOPNOTSUPP;
>  
>  	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
> @@ -2606,9 +2606,9 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>  	if (ret)
>  		return ret;
>  
> -	range.minlen = max((unsigned int)range.minlen,
> -			   bdev_discard_granularity(sb->s_bdev));
> -	ret = f2fs_trim_fs(F2FS_SB(sb), &range);
> +	range.minlen = max_t(unsigned int, range.minlen,
> +			f2fs_hw_discard_granularity(sbi));
> +	ret = f2fs_trim_fs(sbi, &range);
>  	mnt_drop_write_file(filp);
>  	if (ret < 0)
>  		return ret;
> @@ -2616,7 +2616,7 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>  	if (copy_to_user((struct fstrim_range __user *)arg, &range,
>  				sizeof(range)))
>  		return -EFAULT;
> -	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
> +	f2fs_update_time(sbi, REQ_TIME);
>  	return 0;
>  }
>  



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
  2025-10-27  8:35 ` Chao Yu via Linux-f2fs-devel
@ 2025-10-27 13:06   ` Yongpeng Yang
  2025-10-28  2:30     ` Chao Yu via Linux-f2fs-devel
  0 siblings, 1 reply; 6+ messages in thread
From: Yongpeng Yang @ 2025-10-27 13:06 UTC (permalink / raw)
  To: Chao Yu, Yongpeng Yang, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

On 10/27/25 16:35, Chao Yu via Linux-f2fs-devel wrote:
> On 10/24/25 22:37, Yongpeng Yang wrote:
>> From: Yongpeng Yang <yangyongpeng@xiaomi.com>
>>
>> When F2FS uses multiple block devices, each device may have a
>> different discard granularity. The minimum trim granularity must be
>> at least the maximum discard granularity of all devices, excluding
>> zoned devices. Use max_t instead of the max() macro to compute the
>> maximum value.
>>
>> Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
>> ---
>>   fs/f2fs/f2fs.h | 12 ++++++++++++
>>   fs/f2fs/file.c | 12 ++++++------
>>   2 files changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 32fb2e7338b7..064bdbf463f7 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -4762,6 +4762,18 @@ static inline bool f2fs_hw_support_discard(struct f2fs_sb_info *sbi)
>>   	return false;
>>   }
>>   
>> +static inline unsigned int f2fs_hw_discard_granularity(struct f2fs_sb_info *sbi)
>> +{
>> +	int i = 1;
>> +	unsigned int discard_granularity = bdev_discard_granularity(sbi->sb->s_bdev);
> 
> Yongpeng,
> 
> The patch makes sense to me.
> 
> One extra question, if a zoned device contains both conventional zones and
> sequential zones, what discard granularity will it exposes?
> 
> Thanks,
I don't have such a device. I think the exposed discard granularity 
should be that of the conventional zones, since the sequential zones 
have a default reset granularity of 1 zone, and no additional 
information is needed to indicate that.

Yongpeng>
>> +
>> +	if (f2fs_is_multi_device(sbi))
>> +		for (; i < sbi->s_ndevs && !bdev_is_zoned(FDEV(i).bdev); i++)
>> +			discard_granularity = max_t(unsigned int, discard_granularity,
>> +						bdev_discard_granularity(FDEV(i).bdev));
>> +	return discard_granularity;
>> +}
>> +
>>   static inline bool f2fs_realtime_discard_enable(struct f2fs_sb_info *sbi)
>>   {
>>   	return (test_opt(sbi, DISCARD) && f2fs_hw_support_discard(sbi)) ||
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index 6d42e2d28861..ced0f78532c9 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -2588,14 +2588,14 @@ static int f2fs_keep_noreuse_range(struct inode *inode,
>>   static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>   {
>>   	struct inode *inode = file_inode(filp);
>> -	struct super_block *sb = inode->i_sb;
>> +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>   	struct fstrim_range range;
>>   	int ret;
>>   
>>   	if (!capable(CAP_SYS_ADMIN))
>>   		return -EPERM;
>>   
>> -	if (!f2fs_hw_support_discard(F2FS_SB(sb)))
>> +	if (!f2fs_hw_support_discard(sbi))
>>   		return -EOPNOTSUPP;
>>   
>>   	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
>> @@ -2606,9 +2606,9 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>   	if (ret)
>>   		return ret;
>>   
>> -	range.minlen = max((unsigned int)range.minlen,
>> -			   bdev_discard_granularity(sb->s_bdev));
>> -	ret = f2fs_trim_fs(F2FS_SB(sb), &range);
>> +	range.minlen = max_t(unsigned int, range.minlen,
>> +			f2fs_hw_discard_granularity(sbi));
>> +	ret = f2fs_trim_fs(sbi, &range);
>>   	mnt_drop_write_file(filp);
>>   	if (ret < 0)
>>   		return ret;
>> @@ -2616,7 +2616,7 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>   	if (copy_to_user((struct fstrim_range __user *)arg, &range,
>>   				sizeof(range)))
>>   		return -EFAULT;
>> -	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
>> +	f2fs_update_time(sbi, REQ_TIME);
>>   	return 0;
>>   }
>>   
> 
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
  2025-10-27 13:06   ` Yongpeng Yang
@ 2025-10-28  2:30     ` Chao Yu via Linux-f2fs-devel
  2025-10-28  9:27       ` Yongpeng Yang
  0 siblings, 1 reply; 6+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2025-10-28  2:30 UTC (permalink / raw)
  To: Yongpeng Yang, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

On 10/27/25 21:06, Yongpeng Yang wrote:
> On 10/27/25 16:35, Chao Yu via Linux-f2fs-devel wrote:
>> On 10/24/25 22:37, Yongpeng Yang wrote:
>>> From: Yongpeng Yang <yangyongpeng@xiaomi.com>
>>>
>>> When F2FS uses multiple block devices, each device may have a
>>> different discard granularity. The minimum trim granularity must be
>>> at least the maximum discard granularity of all devices, excluding
>>> zoned devices. Use max_t instead of the max() macro to compute the
>>> maximum value.
>>>
>>> Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
>>> ---
>>>   fs/f2fs/f2fs.h | 12 ++++++++++++
>>>   fs/f2fs/file.c | 12 ++++++------
>>>   2 files changed, 18 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 32fb2e7338b7..064bdbf463f7 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -4762,6 +4762,18 @@ static inline bool f2fs_hw_support_discard(struct f2fs_sb_info *sbi)
>>>       return false;
>>>   }
>>>   +static inline unsigned int f2fs_hw_discard_granularity(struct f2fs_sb_info *sbi)
>>> +{
>>> +    int i = 1;
>>> +    unsigned int discard_granularity = bdev_discard_granularity(sbi->sb->s_bdev);
>>
>> Yongpeng,
>>
>> The patch makes sense to me.
>>
>> One extra question, if a zoned device contains both conventional zones and
>> sequential zones, what discard granularity will it exposes?
>>
>> Thanks,
> I don't have such a device. I think the exposed discard granularity should be that of the conventional zones, since the sequential zones have a default reset granularity of 1 zone, and no additional information is needed to indicate that.

I guess you can have a virtual one simulated by null_blk driver?

https://zonedstorage.io/docs/getting-started/zbd-emulation#zoned-block-device-emulation-with-null_blk

- nullblk_create.sh 512 2 1024 1024
- cat /sys/block/nullb1/queue/discard_*
0
0
0
0

I didn't dig into more details, though. :)

Thanks,

> 
> Yongpeng>
>>> +
>>> +    if (f2fs_is_multi_device(sbi))
>>> +        for (; i < sbi->s_ndevs && !bdev_is_zoned(FDEV(i).bdev); i++)
>>> +            discard_granularity = max_t(unsigned int, discard_granularity,
>>> +                        bdev_discard_granularity(FDEV(i).bdev));
>>> +    return discard_granularity;
>>> +}
>>> +
>>>   static inline bool f2fs_realtime_discard_enable(struct f2fs_sb_info *sbi)
>>>   {
>>>       return (test_opt(sbi, DISCARD) && f2fs_hw_support_discard(sbi)) ||
>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>> index 6d42e2d28861..ced0f78532c9 100644
>>> --- a/fs/f2fs/file.c
>>> +++ b/fs/f2fs/file.c
>>> @@ -2588,14 +2588,14 @@ static int f2fs_keep_noreuse_range(struct inode *inode,
>>>   static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>   {
>>>       struct inode *inode = file_inode(filp);
>>> -    struct super_block *sb = inode->i_sb;
>>> +    struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>>       struct fstrim_range range;
>>>       int ret;
>>>         if (!capable(CAP_SYS_ADMIN))
>>>           return -EPERM;
>>>   -    if (!f2fs_hw_support_discard(F2FS_SB(sb)))
>>> +    if (!f2fs_hw_support_discard(sbi))
>>>           return -EOPNOTSUPP;
>>>         if (copy_from_user(&range, (struct fstrim_range __user *)arg,
>>> @@ -2606,9 +2606,9 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>       if (ret)
>>>           return ret;
>>>   -    range.minlen = max((unsigned int)range.minlen,
>>> -               bdev_discard_granularity(sb->s_bdev));
>>> -    ret = f2fs_trim_fs(F2FS_SB(sb), &range);
>>> +    range.minlen = max_t(unsigned int, range.minlen,
>>> +            f2fs_hw_discard_granularity(sbi));
>>> +    ret = f2fs_trim_fs(sbi, &range);
>>>       mnt_drop_write_file(filp);
>>>       if (ret < 0)
>>>           return ret;
>>> @@ -2616,7 +2616,7 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>       if (copy_to_user((struct fstrim_range __user *)arg, &range,
>>>                   sizeof(range)))
>>>           return -EFAULT;
>>> -    f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
>>> +    f2fs_update_time(sbi, REQ_TIME);
>>>       return 0;
>>>   }
>>>   
>>
>>
>>
>> _______________________________________________
>> Linux-f2fs-devel mailing list
>> Linux-f2fs-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> 



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
  2025-10-28  2:30     ` Chao Yu via Linux-f2fs-devel
@ 2025-10-28  9:27       ` Yongpeng Yang
  0 siblings, 0 replies; 6+ messages in thread
From: Yongpeng Yang @ 2025-10-28  9:27 UTC (permalink / raw)
  To: Chao Yu, Yongpeng Yang, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

On 10/28/25 10:30, Chao Yu via Linux-f2fs-devel wrote:
> On 10/27/25 21:06, Yongpeng Yang wrote:
>> On 10/27/25 16:35, Chao Yu via Linux-f2fs-devel wrote:
>>> On 10/24/25 22:37, Yongpeng Yang wrote:
>>>> From: Yongpeng Yang <yangyongpeng@xiaomi.com>
>>>>
>>>> When F2FS uses multiple block devices, each device may have a
>>>> different discard granularity. The minimum trim granularity must be
>>>> at least the maximum discard granularity of all devices, excluding
>>>> zoned devices. Use max_t instead of the max() macro to compute the
>>>> maximum value.
>>>>
>>>> Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
>>>> ---
>>>>    fs/f2fs/f2fs.h | 12 ++++++++++++
>>>>    fs/f2fs/file.c | 12 ++++++------
>>>>    2 files changed, 18 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>>> index 32fb2e7338b7..064bdbf463f7 100644
>>>> --- a/fs/f2fs/f2fs.h
>>>> +++ b/fs/f2fs/f2fs.h
>>>> @@ -4762,6 +4762,18 @@ static inline bool f2fs_hw_support_discard(struct f2fs_sb_info *sbi)
>>>>        return false;
>>>>    }
>>>>    +static inline unsigned int f2fs_hw_discard_granularity(struct f2fs_sb_info *sbi)
>>>> +{
>>>> +    int i = 1;
>>>> +    unsigned int discard_granularity = bdev_discard_granularity(sbi->sb->s_bdev);
>>>
>>> Yongpeng,
>>>
>>> The patch makes sense to me.
>>>
>>> One extra question, if a zoned device contains both conventional zones and
>>> sequential zones, what discard granularity will it exposes?
>>>
>>> Thanks,
>> I don't have such a device. I think the exposed discard granularity should be that of the conventional zones, since the sequential zones have a default reset granularity of 1 zone, and no additional information is needed to indicate that.
> 
> I guess you can have a virtual one simulated by null_blk driver?
> 
> https://zonedstorage.io/docs/getting-started/zbd-emulation#zoned-block-device-emulation-with-null_blk
1. When using qemu to emulate a zns ssd, a namespace cannot 
simultaneously contain both conventional zones and sequential zones. 
Additionally, for the emulated zoned device, the discard_granularity 
cannot be configured manually. Its size is defaulted to the maximum 
value between the logical_block_size and 4KiB.

static int nvme_ns_init_blk(NvmeNamespace *ns, Error **errp)
{
...
     if (ns->blkconf.discard_granularity == -1) {
         ns->blkconf.discard_granularity =
             MAX(ns->blkconf.logical_block_size, MIN_DISCARD_GRANULARITY);
     }
...
}

The default value of discard_granularity is set to logical_block_size in 
nvme driver.
static void nvme_config_discard(struct nvme_ns *ns, struct queue_limits 
*lim)
{
...
	lim->discard_granularity = lim->logical_block_size;
...
}

2. QEMU cannot emulate SMR HDDs. From scsi driver code, I found that the 
discard_granularity of a scsi device is as follows. The value of 
sdkp->unmap_granularity is shared across multiple LUNs, meaning that 
both conventional LUNs and sequential LUNs have the same 
sdkp->unmap_granularity. As a result, the discard_granularity is also 
the same for both types of zones. Therefore, from the driver 
perspective, a zoned device that contains both conventional zones and 
sequential zones will have the same discard_granularity as other 
conventional devices.


static void sd_config_discard(struct scsi_disk *sdkp, struct 
queue_limits *lim,
                 unsigned int mode)
{
...
     lim->discard_granularity = max(sdkp->physical_block_size,
                         sdkp->unmap_granularity * logical_block_size);
...
}

static void sd_read_block_limits(struct scsi_disk *sdkp,
                 struct queue_limits *lim)
{
...
     sdkp->unmap_granularity = get_unaligned_be32(&vpd->data[28]);
...
}

3. It seems that discard_granularity is related to logical_block_size 
and physical_block_size, and is not associated with the zone size. For 
zoned device, discard_granularity is meaningless.

> 
> - nullblk_create.sh 512 2 1024 1024
> - cat /sys/block/nullb1/queue/discard_*
> 0
> 0
> 0
> 0
> 
> I didn't dig into more details, though. :)
> 
> Thanks,
> 

I found that null device didn't config discard_*.
static int null_add_dev(struct nullb_device *dev) 

{
...
         struct queue_limits lim = {
                 .logical_block_size     = dev->blocksize,
                 .physical_block_size    = dev->blocksize,
                 .max_hw_sectors         = dev->max_sectors,
         };
...
}>>
>> Yongpeng>
>>>> +
>>>> +    if (f2fs_is_multi_device(sbi))
>>>> +        for (; i < sbi->s_ndevs && !bdev_is_zoned(FDEV(i).bdev); i++)
>>>> +            discard_granularity = max_t(unsigned int, discard_granularity,
>>>> +                        bdev_discard_granularity(FDEV(i).bdev));
>>>> +    return discard_granularity;
>>>> +}
>>>> +
>>>>    static inline bool f2fs_realtime_discard_enable(struct f2fs_sb_info *sbi)
>>>>    {
>>>>        return (test_opt(sbi, DISCARD) && f2fs_hw_support_discard(sbi)) ||
>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>>> index 6d42e2d28861..ced0f78532c9 100644
>>>> --- a/fs/f2fs/file.c
>>>> +++ b/fs/f2fs/file.c
>>>> @@ -2588,14 +2588,14 @@ static int f2fs_keep_noreuse_range(struct inode *inode,
>>>>    static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>>    {
>>>>        struct inode *inode = file_inode(filp);
>>>> -    struct super_block *sb = inode->i_sb;
>>>> +    struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>>>        struct fstrim_range range;
>>>>        int ret;
>>>>          if (!capable(CAP_SYS_ADMIN))
>>>>            return -EPERM;
>>>>    -    if (!f2fs_hw_support_discard(F2FS_SB(sb)))
>>>> +    if (!f2fs_hw_support_discard(sbi))
>>>>            return -EOPNOTSUPP;
>>>>          if (copy_from_user(&range, (struct fstrim_range __user *)arg,
>>>> @@ -2606,9 +2606,9 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>>        if (ret)
>>>>            return ret;
>>>>    -    range.minlen = max((unsigned int)range.minlen,
>>>> -               bdev_discard_granularity(sb->s_bdev));
>>>> -    ret = f2fs_trim_fs(F2FS_SB(sb), &range);
>>>> +    range.minlen = max_t(unsigned int, range.minlen,
>>>> +            f2fs_hw_discard_granularity(sbi));
>>>> +    ret = f2fs_trim_fs(sbi, &range);
>>>>        mnt_drop_write_file(filp);
>>>>        if (ret < 0)
>>>>            return ret;
>>>> @@ -2616,7 +2616,7 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
>>>>        if (copy_to_user((struct fstrim_range __user *)arg, &range,
>>>>                    sizeof(range)))
>>>>            return -EFAULT;
>>>> -    f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
>>>> +    f2fs_update_time(sbi, REQ_TIME);
>>>>        return 0;
>>>>    }
>>>>    
>>>
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices
  2025-10-24 14:37 [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices Yongpeng Yang
  2025-10-27  8:35 ` Chao Yu via Linux-f2fs-devel
@ 2025-10-29  9:42 ` Chao Yu via Linux-f2fs-devel
  1 sibling, 0 replies; 6+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2025-10-29  9:42 UTC (permalink / raw)
  To: Yongpeng Yang, Jaegeuk Kim; +Cc: Yongpeng Yang, linux-f2fs-devel

On 10/24/25 22:37, Yongpeng Yang wrote:
> From: Yongpeng Yang <yangyongpeng@xiaomi.com>
> 
> When F2FS uses multiple block devices, each device may have a
> different discard granularity. The minimum trim granularity must be
> at least the maximum discard granularity of all devices, excluding
> zoned devices. Use max_t instead of the max() macro to compute the
> maximum value.
> 
> Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2025-10-29  9:43 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-10-24 14:37 [f2fs-dev] [PATCH] f2fs: ensure minimum trim granularity accounts for all devices Yongpeng Yang
2025-10-27  8:35 ` Chao Yu via Linux-f2fs-devel
2025-10-27 13:06   ` Yongpeng Yang
2025-10-28  2:30     ` Chao Yu via Linux-f2fs-devel
2025-10-28  9:27       ` Yongpeng Yang
2025-10-29  9:42 ` Chao Yu via Linux-f2fs-devel

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).