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Date: Wed, 6 Dec 2023 11:21:43 +1100
From: David Disseldorp <ddiss@suse.de>
To: David Sterba <dsterba@suse.cz>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] btrfs: drop unused memparse() parameter
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On Tue, 5 Dec 2023 15:22:53 +0100, David Sterba wrote:

> On Tue, Dec 05, 2023 at 10:13:29PM +1100, David Disseldorp wrote:
> > The @retptr parameter for memparse() is optional.
> > btrfs_devinfo_scrub_speed_max_store() doesn't use it for any input
> > validation, so the parameter can be dropped.  
> 
> Or should it be used for validation? memparse is also used in
> btrfs_chunk_size_store() that accepts whitespace as trailing characters
> (namely '\n' if the value is from echo).

It probably should have been used for validation when originally added,
but the current behaviour is now part of the sysfs scrub_speed_max API.
Failing on invalid input would break scripts which do things like
  echo clear > /sys/fs/btrfs/UUID/devinfo/1/scrub_speed_max

Cheers, David