Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 4 Jul 2023 13:43:51 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Jan Kara <jack@suse.cz>
Cc:     linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Jens Axboe <axboe@kernel.dk>,
        Christoph Hellwig <hch@infradead.org>,
        Alasdair Kergon <agk@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Anna Schumaker <anna@kernel.org>, Chao Yu <chao@kernel.org>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        "Darrick J. Wong" <djwong@kernel.org>,
        Dave Kleikamp <shaggy@kernel.org>,
        David Sterba <dsterba@suse.com>, dm-devel@redhat.com,
        drbd-dev@lists.linbit.com, Gao Xiang <xiang@kernel.org>,
        Jack Wang <jinpu.wang@ionos.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        jfs-discussion@lists.sourceforge.net,
        Joern Engel <joern@lazybastard.org>,
        Joseph Qi <joseph.qi@linux.alibaba.com>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        linux-bcache@vger.kernel.org, linux-btrfs@vger.kernel.org,
        linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org,
        linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org,
        linux-nilfs@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-pm@vger.kernel.org, linux-raid@vger.kernel.org,
        linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org,
        linux-xfs@vger.kernel.org,
        "Md. Haris Iqbal" <haris.iqbal@ionos.com>,
        Mike Snitzer <snitzer@kernel.org>,
        Minchan Kim <minchan@kernel.org>, ocfs2-devel@oss.oracle.com,
        reiserfs-devel@vger.kernel.org,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Song Liu <song@kernel.org>,
        Sven Schnelle <svens@linux.ibm.com>,
        target-devel@vger.kernel.org, Ted Tso <tytso@mit.edu>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        xen-devel@lists.xenproject.org
Subject: Re: [PATCH 01/32] block: Provide blkdev_get_handle_* functions
Message-ID: <ZKQUB4rU8Gebhq6R@casper.infradead.org>
References: <20230629165206.383-1-jack@suse.cz>
 <20230704122224.16257-1-jack@suse.cz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230704122224.16257-1-jack@suse.cz>
Precedence: bulk

On Tue, Jul 04, 2023 at 02:21:28PM +0200, Jan Kara wrote:
> +struct bdev_handle *blkdev_get_handle_by_dev(dev_t dev, blk_mode_t mode,
> +		void *holder, const struct blk_holder_ops *hops)
> +{
> +	struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle),
> +					     GFP_KERNEL);
> +	struct block_device *bdev;
> +
> +	if (!handle)
> +		return ERR_PTR(-ENOMEM);
> +	bdev = blkdev_get_by_dev(dev, mode, holder, hops);
> +	if (IS_ERR(bdev))
> +		return ERR_CAST(bdev);

Would we be better off with a handle->error (and a NULL return from this
function means "we couldn't allocate a handle")?  I have no objection
to what you've done here, just wondering if it might end up nicer for
the users.