From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
Oleksii Kurochko <olkuroch@cisco.com>,
Sagi Grimberg <sagi@grimberg.me>,
Mike Snitzer <snitzer@redhat.com>,
Ilya Dryomov <idryomov@gmail.com>,
Dongsheng Yang <dongsheng.yang@easystack.cn>,
ceph-devel@vger.kernel.org, dm-devel@redhat.com,
linux-block@vger.kernel.org, linux-nvme@lists.infradead.org
Subject: Re: [PATCH 1/4] block: add a hard-readonly flag to struct gendisk
Date: Wed, 02 Dec 2020 23:04:33 -0500 [thread overview]
Message-ID: <yq17dpza6nz.fsf@ca-mkp.ca.oracle.com> (raw)
In-Reply-To: <20201129181926.897775-2-hch@lst.de> (Christoph Hellwig's message of "Sun, 29 Nov 2020 19:19:23 +0100")
Hi Christoph!
> - If BLKROSET is used to set a whole-disk device read-only, any
> partitions will end up in a read-only state until the user
> explicitly clears the flag.
This no longer appears to be the case with your tweak.
It's very common for database folks to twiddle the read-only state of
block devices and partitions. I know that our users will find it very
counter-intuitive that setting /dev/sda read-only won't prevent writes
to /dev/sda1.
> int bdev_read_only(struct block_device *bdev)
> {
> if (!bdev)
> return 0;
> - return bdev->bd_read_only;
> + return bdev->bd_read_only ||
> + test_bit(GD_READ_ONLY, &bdev->bd_disk->state);
> }
I suggest doing bd->bd_read_only || get_disk_ro(...) here. That does
take part0 into account.
> static inline int get_disk_ro(struct gendisk *disk)
> {
> - return disk->part0->bd_read_only;
> + return disk->part0->bd_read_only ||
> + test_bit(GD_READ_ONLY, &disk->state);
> }
>
> extern void disk_block_events(struct gendisk *disk);
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2020-12-03 4:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-29 18:19 split hard read-only vs read-only policy v2 Christoph Hellwig
2020-11-29 18:19 ` [PATCH 1/4] block: add a hard-readonly flag to struct gendisk Christoph Hellwig
2020-11-30 1:23 ` Alex Elder
2020-11-30 7:55 ` Hannes Reinecke
2020-12-03 4:04 ` Martin K. Petersen [this message]
2020-12-03 8:53 ` Christoph Hellwig
2020-12-03 14:01 ` Martin K. Petersen
2020-11-29 18:19 ` [PATCH 2/4] rbd: remove the ->set_read_only method Christoph Hellwig
2020-11-30 7:56 ` Hannes Reinecke
2020-11-29 18:19 ` [PATCH 3/4] nvme: allow revalidate to set a namespace read-only Christoph Hellwig
2020-11-29 21:13 ` Chaitanya Kulkarni
2020-11-30 7:57 ` Hannes Reinecke
2020-11-29 18:19 ` [PATCH 4/4] dm: use bdev_read_only to check if a device is read-only Christoph Hellwig
2020-11-30 7:58 ` Hannes Reinecke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=yq17dpza6nz.fsf@ca-mkp.ca.oracle.com \
--to=martin.petersen@oracle.com \
--cc=axboe@kernel.dk \
--cc=ceph-devel@vger.kernel.org \
--cc=dm-devel@redhat.com \
--cc=dongsheng.yang@easystack.cn \
--cc=hch@lst.de \
--cc=idryomov@gmail.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=olkuroch@cisco.com \
--cc=sagi@grimberg.me \
--cc=snitzer@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).