From: Bart Van Assche <bvanassche@acm.org>
To: Luis Chamberlain <mcgrof@kernel.org>,
axboe@kernel.dk, viro@zeniv.linux.org.uk,
gregkh@linuxfoundation.org, rostedt@goodmis.org,
mingo@redhat.com, jack@suse.cz, ming.lei@redhat.com,
nstange@suse.de, akpm@linux-foundation.org
Cc: mhocko@suse.com, yukuai3@huawei.com, linux-block@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 4/5] blktrace: break out of blktrace setup on concurrent calls
Date: Sat, 9 May 2020 18:09:38 -0700 [thread overview]
Message-ID: <e728acea-61c1-fcb5-489b-9be8cafe61ea@acm.org> (raw)
In-Reply-To: <20200509031058.8239-5-mcgrof@kernel.org>
On 2020-05-08 20:10, Luis Chamberlain wrote:
> @@ -493,6 +496,12 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
> */
> strreplace(buts->name, '/', '_');
>
> + if (q->blk_trace) {
> + pr_warn("Concurrent blktraces are not allowed on %s\n",
> + buts->name);
> + return -EBUSY;
> + }
> +
> bt = kzalloc(sizeof(*bt), GFP_KERNEL);
> if (!bt)
> return -ENOMEM;
Is this really sufficient? Shouldn't concurrent do_blk_trace_setup()
calls that refer to the same request queue be serialized to really
prevent that debugfs attribute creation fails?
How about using the block device name instead of the partition name in
the error message since the concurrency context is the block device and
not the partition?
Thanks,
Bart.
next prev parent reply other threads:[~2020-05-10 1:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 3:10 [PATCH v4 0/5] block: fix blktrace debugfs use after free Luis Chamberlain
2020-05-09 3:10 ` [PATCH v4 1/5] block: revert back to synchronous request_queue removal Luis Chamberlain
2020-05-10 0:36 ` Bart Van Assche
2020-05-10 6:20 ` Greg KH
2020-05-11 13:41 ` Luis Chamberlain
2020-05-09 3:10 ` [PATCH v4 2/5] block: move main block debugfs initialization to its own file Luis Chamberlain
2020-05-09 3:10 ` [PATCH v4 3/5] blktrace: fix debugfs use after free Luis Chamberlain
2020-05-10 0:58 ` Bart Van Assche
2020-05-11 13:44 ` Luis Chamberlain
2020-05-10 6:26 ` Greg KH
2020-05-11 14:03 ` Luis Chamberlain
2020-05-09 3:10 ` [PATCH v4 4/5] blktrace: break out of blktrace setup on concurrent calls Luis Chamberlain
2020-05-10 1:09 ` Bart Van Assche [this message]
2020-05-11 13:39 ` Luis Chamberlain
2020-05-16 1:39 ` Luis Chamberlain
2020-05-09 3:10 ` [PATCH v4 5/5] loop: be paranoid on exit and prevent new additions / removals Luis Chamberlain
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=e728acea-61c1-fcb5-489b-9be8cafe61ea@acm.org \
--to=bvanassche@acm.org \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=gregkh@linuxfoundation.org \
--cc=jack@suse.cz \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mcgrof@kernel.org \
--cc=mhocko@suse.com \
--cc=ming.lei@redhat.com \
--cc=mingo@redhat.com \
--cc=nstange@suse.de \
--cc=rostedt@goodmis.org \
--cc=viro@zeniv.linux.org.uk \
--cc=yukuai3@huawei.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).