From: Matteo Croce <mcroce@linux.microsoft.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Lennart Poettering <lennart@poettering.net>,
Luca Boccassi <bluca@debian.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Damien Le Moal <damien.lemoal@wdc.com>, Tejun Heo <tj@kernel.org>,
"Javier Gonz??lez" <javier@javigon.com>,
Niklas Cassel <niklas.cassel@wdc.com>,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Hannes Reinecke <hare@suse.de>,
Matthew Wilcox <willy@infradead.org>,
JeffleXu <jefflexu@linux.alibaba.com>
Subject: Re: [PATCH v3 1/6] block: add disk sequence number
Date: Wed, 23 Jun 2021 15:10:21 +0200 [thread overview]
Message-ID: <CAFnufp1gdag0rGQ8K4_2oB6_aC+EZgfgwd2eL4-AxpG0mK+_qQ@mail.gmail.com> (raw)
In-Reply-To: <YNMffBWvs/Fz2ptK@infradead.org>
On Wed, Jun 23, 2021 at 1:49 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Wed, Jun 23, 2021 at 12:58:53PM +0200, Matteo Croce wrote:
> > +void inc_diskseq(struct gendisk *disk)
> > +{
> > + static atomic64_t diskseq;
>
> Please don't hide file scope variables in functions.
>
I just didn't want to clobber that file namespace, as that is the only
point where it's used.
> Can you explain a little more why we need a global sequence count vs
> a per-disk one here?
The point of the whole series is to have an unique sequence number for
all the disks.
Events can arrive to the userspace delayed or out-of-order, so this
helps to correlate events to the disk.
It might seem strange, but there isn't a way to do this yet, so I come
up with a global, monotonically incrementing number.
--
per aspera ad upstream
next prev parent reply other threads:[~2021-06-23 13:11 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 10:58 [PATCH v3 0/6] block: add a sequence number to disks Matteo Croce
2021-06-23 10:58 ` [PATCH v3 1/6] block: add disk sequence number Matteo Croce
2021-06-23 11:48 ` Christoph Hellwig
2021-06-23 13:10 ` Matteo Croce [this message]
2021-06-23 13:51 ` Lennart Poettering
2021-06-23 14:01 ` Hannes Reinecke
2021-06-23 14:07 ` Luca Boccassi
2021-06-23 14:21 ` Hannes Reinecke
2021-06-23 14:34 ` Luca Boccassi
2021-06-23 14:55 ` Lennart Poettering
2021-06-23 14:12 ` Lennart Poettering
2021-06-23 15:02 ` Hannes Reinecke
2021-06-23 15:34 ` Luca Boccassi
2021-06-23 15:48 ` Lennart Poettering
2021-06-23 14:28 ` Christoph Hellwig
2021-06-23 10:58 ` [PATCH v3 2/6] block: add ioctl to read the " Matteo Croce
2021-06-23 10:58 ` [PATCH v3 3/6] block: refactor sysfs code Matteo Croce
2021-06-23 11:52 ` Christoph Hellwig
2021-06-23 19:03 ` Matteo Croce
2021-06-24 6:12 ` Christoph Hellwig
2021-06-23 10:58 ` [PATCH v3 4/6] block: export diskseq in sysfs Matteo Croce
2021-06-23 10:58 ` [PATCH v3 5/6] block: increment sequence number Matteo Croce
2021-06-23 10:58 ` [PATCH v3 6/6] loop: " Matteo Croce
2021-06-23 11:57 ` Christoph Hellwig
2021-06-23 13:13 ` Luca Boccassi
2021-06-23 14:25 ` Christoph Hellwig
2021-06-23 15:29 ` Lennart Poettering
2021-06-24 6:11 ` Christoph Hellwig
2021-06-23 12:03 ` [PATCH v3 0/6] block: add a sequence number to disks Hannes Reinecke
2021-06-23 12:46 ` Luca Boccassi
2021-06-23 14:07 ` Lennart Poettering
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=CAFnufp1gdag0rGQ8K4_2oB6_aC+EZgfgwd2eL4-AxpG0mK+_qQ@mail.gmail.com \
--to=mcroce@linux.microsoft.com \
--cc=axboe@kernel.dk \
--cc=bluca@debian.org \
--cc=damien.lemoal@wdc.com \
--cc=hare@suse.de \
--cc=hch@infradead.org \
--cc=javier@javigon.com \
--cc=jefflexu@linux.alibaba.com \
--cc=johannes.thumshirn@wdc.com \
--cc=lennart@poettering.net \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=niklas.cassel@wdc.com \
--cc=tj@kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
/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).