Re: [PATCH 20/22] xfs: add support for lazy direct read bounce buffering

Anuj Gupta/Anuj Gupta <[email protected]> Mon, 27 Jul 2026 19:44:32 +0530
Newsgroups org.kernel.vger.linux-xfs,org.kernel.vger.linux-block,org.kernel.vger.linux-fsdevel
Message-ID <[email protected]>
On 7/23/2026 8:19 PM, Christoph Hellwig wrote:
> +static ssize_t
> +read_bounce_store(
> +	struct kobject	*kobj,
> +	const char	*buf,
> +	size_t		count)
> +{
> +	struct xfs_mount	*mp = csum_to_mp(kobj);
> +
> +	if (!strcmp(buf, "never"))
> +		WRITE_ONCE(mp->m_read_bounce, XFS_READ_BOUNCE_NEVER);
> +	else if (!strcmp(buf, "always"))
> +		WRITE_ONCE(mp->m_read_bounce, XFS_READ_BOUNCE_ALWAYS);
> +	else if (!strcmp(buf, "lazy"))
> +		WRITE_ONCE(mp->m_read_bounce, XFS_READ_BOUNCE_LAZY);
it returns a -EINVAL always.

# echo always > /sys/fs/xfs/nvme0n1/csum/read_bounce
bash: echo: write error: Invalid argument

Maybe use sysfs_streq here?