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Date: Fri, 10 Jan 2025 10:56:01 +0100
From: Christoph Hellwig <hch@lst.de>
To: John Garry <john.g.garry@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
	Damien Le Moal <dlemoal@kernel.org>, Ming Lei <ming.lei@redhat.com>,
	Nilay Shroff <nilay@linux.ibm.com>, linux-block@vger.kernel.org,
	linux-nvme@lists.infradead.org, nbd@other.debian.org,
	linux-scsi@vger.kernel.org, usb-storage@lists.one-eyed-alien.net,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>
Subject: Re: [PATCH 05/11] block: add a store_limit operations for sysfs
 entries
Message-ID: <20250110095601.GA11121@lst.de>
References: <20250110054726.1499538-1-hch@lst.de> <20250110054726.1499538-6-hch@lst.de> <e7177a33-aebd-4828-87b0-f790b4fb1306@oracle.com> <20250110091859.GA8373@lst.de> <68cd5371-f4ca-44c0-8ac7-c734da04f877@oracle.com>
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On Fri, Jan 10, 2025 at 09:51:18AM +0000, John Garry wrote:
> ok, and that just comes down to the behavior of queue_var_store(), which 
> mimics sysfs_ops.store
>
> I will note that queue_var_store and queue_var_store64 differ in behaviour 
> here :(
>
>> ->store_limits uses
>> the simpler and harder to get wrong convention of returning 0 on
>> success.
>>
>
> understood, so any reason why not to change the rest (apart from being 
> busy)?

Not real urge.  The idea here was to get it right for the new one.
Changing the existing would be a lot of churn for a relatively small
improvement.  For me that's only worth it when touching the area anyway.
Which might or might not happen when trying to remove the sysfs_lock
around ->store.