From: David Laight <David.Laight@ACULAB.COM>
To: 'Ivan Babrou' <ivan@cloudflare.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel-team@cloudflare.com" <kernel-team@cloudflare.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>, Theodore Ts'o <tytso@mit.edu>,
Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>,
Vincent Whitchurch <vincent.whitchurch@axis.com>,
Mike Rapoport <rppt@kernel.org>, Yang Shi <shy828301@gmail.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
"Kalesh Singh" <kaleshsingh@google.com>
Subject: RE: [PATCH] proc: report open files as size in stat() for /proc/pid/fd
Date: Wed, 21 Sep 2022 10:21:24 +0000 [thread overview]
Message-ID: <b6aa0151527a4ee39ae85dfd34e71864@AcuMS.aculab.com> (raw)
In-Reply-To: <20220920190617.2539-1-ivan@cloudflare.com>
From: Ivan Babrou
> Sent: 20 September 2022 20:06
...
>
> +static int proc_readfd_count(struct inode *inode)
> +{
> + struct task_struct *p = get_proc_task(inode);
> + struct fdtable *fdt;
> + unsigned int i, size, open_fds = 0;
> +
> + if (!p)
> + return -ENOENT;
> +
> + if (p->files) {
> + fdt = files_fdtable(p->files);
> + size = fdt->max_fds;
> +
> + for (i = size / BITS_PER_LONG; i > 0;)
> + open_fds += hweight64(fdt->open_fds[--i]);
> + }
> +
> + return open_fds;
> +}
> +
Doesn't that need (at least) rcu protection?
There might also be issues reading p->files twice.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-09-21 10:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 19:06 [PATCH] proc: report open files as size in stat() for /proc/pid/fd Ivan Babrou
2022-09-21 10:21 ` David Laight [this message]
2022-09-21 18:08 ` Ivan Babrou
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