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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 v2 0/29] block: Make blkdev_get_by_*() return handle Message-ID: <20230825015843.GB95084@ZenIV> References: <20230810171429.31759-1-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230810171429.31759-1-jack@suse.cz> X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 2D90F40007 X-Stat-Signature: muepug8twagdnxynmqhjpr4e5ajeibs6 X-Rspam-User: X-HE-Tag: 1692928764-569195 X-HE-Meta: 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 oyOPlWj3 E0iEY1hT3TLM1z6AHx4HKf9Vw9yNaC4C8SZXfr/ORcX03v38tyBtuikLVul2vxbwzI/pQ77Z6UouiWyIbrxZ7rUt0KV+X/qENlKREGWe62LNf+psganhBA7fqn2dicAodfxM2k80kVtWc0+BVpcrPKd8YY4sdrQ5KoTgTzOX3+vFVk9bd8uk2JHnorzQdwoj2TuxMRnLj4EB7diSPsg6CDOjub4IUnuCAs+4EsZlxV9Al+/c/mjh0oaPX8yCErl5dhtnfjDKVvz559p2CJI1L/FS4O6hQ0zhSLDDtHeCsgUcDOuOl7G8sDycr7XS3Q7wnKtuwSFQiKTY07XAfFzuFki+/573aIzHjJ3SFpdZS39paRZl1be2Gf6+BAS+Tess2CQ0Zj/sLdggUuVWYQPiJBocoPwXgUqHxMHYAtLRyGfsm3+VuA1YG4R1FeN0oMVzApER0CisAeVanM4s2dUKUF3pKja3uGmNPonBxcNex7Yy66el7ZRYVR8/GQfMKvhY78ZLCIgwjhaHwimQasxuc4k9DAQdc1v3pyyVDdC6lLCPNn90WKC+148/Vjr5JMQpZzcjcjxNWfsUasQfbuDo+O4rLTEF3lL+KZqbMmktCLaq8PLU= 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 Fri, Aug 11, 2023 at 01:04:31PM +0200, Jan Kara wrote: > Hello, > > this is a v2 of the patch series which implements the idea of blkdev_get_by_*() > calls returning bdev_handle which is then passed to blkdev_put() [1]. This > makes the get and put calls for bdevs more obviously matching and allows us to > propagate context from get to put without having to modify all the users > (again!). In particular I need to propagate used open flags to blkdev_put() to > be able count writeable opens and add support for blocking writes to mounted > block devices. I'll send that series separately. > > The series is based on Christian's vfs tree as of yesterday as there is quite > some overlap. Patches have passed some reasonable testing - I've tested block > changes, md, dm, bcache, xfs, btrfs, ext4, swap. This obviously doesn't cover > everything so I'd like to ask respective maintainers to review / test their > changes. Thanks! I've pushed out the full branch to: > > git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle > > to ease review / testing. Hmm... Completely Insane Idea(tm): how about turning that thing inside out and having your bdev_open_by... return an actual opened struct file? After all, we do that for sockets and pipes just fine and that's a whole lot hotter area. Suppose we leave blkdev_open()/blkdev_release() as-is. No need to mess with what we have for normal opened files for block devices. And have block_open_by_dev() that would find bdev, etc., same yours does and shove it into anon file. Paired with plain fput() - no need to bother with new primitives for closing. With a helper returning I_BDEV(bdev_file_inode(file)) to get from those to bdev. NOTE: I'm not suggesting replacing ->s_bdev with struct file * if we do that - we want that value cached, obviously. Just store both... Not saying it's a good idea, but... might be interesting to look into. Comments?