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Date: Fri, 10 Jan 2025 10:18:59 +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
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References: <20250110054726.1499538-1-hch@lst.de> <20250110054726.1499538-6-hch@lst.de> <e7177a33-aebd-4828-87b0-f790b4fb1306@oracle.com>
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On Fri, Jan 10, 2025 at 09:15:09AM +0000, John Garry wrote:
>> +	int (*store_limit)(struct gendisk *disk, const char *page,
>
> I don't really see why this returns an int, while the queue features 
> callback methods return a ssize_t. I know that the res variable in 
> queue_attr_store() gets mixed with an int for updating the queue limits, 
> but I don't see that as a reason to use int here.

The normal store methods have the annoying calling convention where
they return the parsed string length on success.  ->store_limits uses
the simpler and harder to get wrong convention of returning 0 on
success.