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Wong" , Dave Kleikamp , David Sterba , dm-devel@redhat.com, drbd-dev@lists.linbit.com, Gao Xiang , Jack Wang , Jaegeuk Kim , jfs-discussion@lists.sourceforge.net, Joern Engel , Joseph Qi , Kent Overstreet , 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" , Mike Snitzer , Minchan Kim , ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, Sergey Senozhatsky , Song Liu , Sven Schnelle , target-devel@vger.kernel.org, Ted Tso , Trond Myklebust , xen-devel@lists.xenproject.org Subject: Re: [PATCH 01/32] block: Provide blkdev_get_handle_* functions Message-ID: <20230704130356.xwdlxvgvi4l6sruc@quack3> 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: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 4009F140009 X-Stat-Signature: 83ijyej5o6y1fqsswdc7akns6razkxig X-Rspam-User: X-HE-Tag: 1688475838-820665 X-HE-Meta: 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 lIVOcRBo OEtODJSDTDcLsRDBNc3IWN/zlvPfKw1oMoO05xR7Lwv8hFVrwwhdw4k0q/aXy9p63B4Kj26X3r+uxh+7+QCsZLZRZqla3s1K1jbNKDcm6Cw85bdeXXIq5KIGHbq47DOwakIv1Y/iLGHZvqoF9MYR6aw+w4syPKXXKZd6WXyejbJ3UmacKtN1zOL++URpvFl5IZmwwsvnb5vJMMRqXUOmStbdVyoPotohU4s9IPskAHHAfBciM9xZ1BzNTu1n6M1Rj092Zy9NkPgmIp3/PyxisV2LkmNW+peZKLxiSsmgrm6cJnXX+YAnVVEt25Irco0aKm2U93txpbWrZG8ICtgHV1zk6M/PRGgbqAApfdD/un3NjUhq+UXgCMMKDLA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 04-07-23 13:43:51, Matthew Wilcox wrote: > 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. Hum, I've checked a couple of users and it seems it would be more complicated for the users to handle this convention than the one I've chosen. And that one is also pretty standard so I think by the principle of least surprise it is also better. Honza > -- Jan Kara SUSE Labs, CR