From: "Michal Suchánek" <msuchanek@suse.de>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-scsi@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
Jens Axboe <axboe@kernel.dk>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Eric Biggers <ebiggers@google.com>,
"J. Bruce Fields" <bfields@redhat.com>,
Benjamin Coddington <bcodding@redhat.com>,
Hannes Reinecke <hare@suse.com>, Omar Sandoval <osandov@fb.com>,
Ming Lei <ming.lei@redhat.com>,
Damien Le Moal <damien.lemoal@wdc.com>,
Bart Van Assche <bvanassche@acm.org>, Tejun Heo <tj@kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 6/8] bdev: add open_finish.
Date: Thu, 24 Oct 2019 10:55:14 +0200 [thread overview]
Message-ID: <20191024085514.GI938@kitsune.suse.cz> (raw)
In-Reply-To: <20191024022232.GB11485@infradead.org>
On Wed, Oct 23, 2019 at 07:22:32PM -0700, Christoph Hellwig wrote:
> On Wed, Oct 23, 2019 at 02:52:45PM +0200, Michal Suchanek wrote:
> > Opening a block device may require a long operation such as waiting for
> > the cdrom tray to close. Performing this operation with locks held locks
> > out other attempts to open the device. These processes waiting to open
> > the device are not killable.
> >
> > To avoid this issue and still be able to perform time-consuming checks
> > at open() time the block device driver can provide open_finish(). If it
> > does opening the device proceeds even when an error is returned from
> > open(), bd_mutex is released and open_finish() is called. If
> > open_finish() succeeds the device is now open, if it fails release() is
> > called.
> >
> > When -ERESTARTSYS is returned from open() blkdev_get may loop without
> > calling open_finish(). On -ERESTARTSYS open_finish() is not called.
> >
> > Move a ret = 0 assignment up in the if/else branching to avoid returning
> > -ENXIO. Previously the return value was ignored on the unhandled branch.
>
> This just doesn't make much sense. There is no point in messing up
> the block API for ugly workarounds like that.
If you have ideas how to do this better then share them.
Thanks
Michal
next prev parent reply other threads:[~2019-10-24 8:55 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-23 12:52 [PATCH v2 0/8] Fix cdrom autoclose Michal Suchanek
2019-10-23 12:52 ` [PATCH v2 1/8] cdrom: add poll_event_interruptible Michal Suchanek
2019-10-23 12:52 ` [PATCH v2 2/8] cdrom: factor out common open_for_* code Michal Suchanek
2019-10-24 2:19 ` Christoph Hellwig
2019-10-24 8:50 ` Michal Suchánek
2019-10-25 2:39 ` Christoph Hellwig
2019-10-25 10:42 ` Michal Suchánek
2019-10-26 6:46 ` Finn Thain
2019-10-24 13:23 ` Matthew Wilcox
2019-10-25 2:38 ` Christoph Hellwig
2019-10-23 12:52 ` [PATCH v2 3/8] cdrom: wait for the tray to close Michal Suchanek
2019-10-23 12:52 ` [PATCH v2 4/8] cdrom: separate autoclose into an IOCTL Michal Suchanek
2019-10-23 12:52 ` [PATCH v2 5/8] docs: cdrom: Add autoclose IOCTL Michal Suchanek
2019-10-23 12:52 ` [PATCH v2 6/8] bdev: add open_finish Michal Suchanek
2019-10-24 2:22 ` Christoph Hellwig
2019-10-24 8:55 ` Michal Suchánek [this message]
2019-10-24 13:12 ` Matthew Wilcox
2019-10-24 13:19 ` Michal Suchánek
2019-11-21 10:15 ` Michal Suchánek
2019-10-23 12:52 ` [PATCH v2 7/8] scsi: sr: workaround VMware ESXi cdrom emulation bug Michal Suchanek
2019-10-23 14:13 ` Hannes Reinecke
2019-10-23 16:23 ` Michal Suchánek
2019-10-23 21:44 ` Ewan D. Milne
2019-10-24 5:46 ` Hannes Reinecke
2019-10-24 8:56 ` Michal Suchánek
2019-10-24 9:41 ` Hannes Reinecke
2019-10-24 10:11 ` Michal Suchánek
2019-10-24 11:45 ` [PATCH RFC] scsi: blacklist: add VMware ESXi cdrom - broken tray emulation Michal Suchanek
2019-10-24 2:23 ` [PATCH v2 7/8] scsi: sr: workaround VMware ESXi cdrom emulation bug Christoph Hellwig
2019-10-24 8:53 ` Michal Suchánek
2019-11-21 15:21 ` Michal Suchánek
2019-10-23 12:52 ` [PATCH v2 8/8] scsi: sr: wait for the medium to become ready Michal Suchanek
2019-10-24 2:24 ` Christoph Hellwig
2019-10-24 8:51 ` Michal Suchánek
2019-10-24 13:14 ` Matthew Wilcox
2019-10-26 14:57 ` [scsi] 9ed2563662: BUG:kernel_NULL_pointer_dereference,address kernel test robot
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