linux-kernel - Re: [PATCH v2] ext4: fix to report fstrim.minlen back to userspace

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Message-ID: <20230421093940.k2crghkblpx2fqlv@quack3>
Date:   Fri, 21 Apr 2023 11:39:40 +0200
From:   Jan Kara <jack@...e.cz>
To:     Chao Yu <chao@...nel.org>
Cc:     Theodore Ts'o <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] ext4: fix to report fstrim.minlen back to userspace

On Thu 06-04-23 23:04:10, Chao Yu wrote:
> Quoted from manual of fstrim(8):
> 
> "-m, --minimum minimum-size
> 	..., if it's smaller than the device's minimum, and report that
> (fstrim_range.minlen) back to userspace."
> 
> So this patch tries to report adjusted fstrim_range.minlen back to
> userspace via FITRIM interface, if the value is smaller than device's
> minimum discard granularity.
> 
> Signed-off-by: Chao Yu <chao@...nel.org>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@...e.cz>

								Honza

> ---
> v2:
> - fix the wrong calculation of range->minlen.
>  fs/ext4/mballoc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index d8b9d6a83d1e..4af51a16fc64 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6491,6 +6491,10 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
>  				discard_granularity >> sb->s_blocksize_bits);
>  		if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
>  			goto out;
> +
> +		/* Report adjusted minlen back to userspace */
> +		range->minlen = EXT4_C2B(EXT4_SB(sb), minlen) <<
> +						sb->s_blocksize_bits;
>  	}
>  	if (end >= max_blks - 1) {
>  		end = max_blks - 1;
> -- 
> 2.25.1
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR