From: "Drew DeVault" <sir@cmpwn.com>
To: "Matthew Wilcox" <willy@infradead.org>
Cc: <linux-fsdevel@vger.kernel.org>, <linux-api@vger.kernel.org>,
"Aleksa Sarai" <cyphar@cyphar.com>
Subject: Re: [RFC PATCH] fs: introduce mkdirat2 syscall for atomic mkdir
Date: Sun, 28 Feb 2021 08:57:20 -0500 [thread overview]
Message-ID: <C9L7SV0Z2GZR.K2C3O186WDJ7@taiga> (raw)
In-Reply-To: <20210228040345.GO2723601@casper.infradead.org>
On Sat Feb 27, 2021 at 11:03 PM EST, Matthew Wilcox wrote:
> > 1. Program A creates a directory
> > 2. Program A is pre-empted
> > 3. Program B deletes the directory
> > 4. Program A creates a file in that directory
> > 5. RIP
>
> umm ... program B deletes the directory. program A opens it in order to
> use openat(). program A gets ENOENT and exits, confused. that's the
> race you're removing here -- and it seems fairly insignificant to me.
Yes, that is the race being eliminated here. Instead of this, program A
has an fd which holds a reference to the directory, so it just works. A
race is a race. It's an oversight in the API.
next prev parent reply other threads:[~2021-02-28 13:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-28 0:25 [RFC PATCH] fs: introduce mkdirat2 syscall for atomic mkdir Drew DeVault
2021-02-28 2:13 ` Al Viro
2021-02-28 2:21 ` Drew DeVault
2021-02-28 2:58 ` Al Viro
2021-02-28 13:56 ` Drew DeVault
2021-03-01 19:02 ` J. Bruce Fields
2021-03-08 13:50 ` Stefan Metzmacher
2021-02-28 2:24 ` Matthew Wilcox
2021-02-28 2:26 ` Drew DeVault
2021-02-28 4:03 ` Matthew Wilcox
2021-02-28 13:57 ` Drew DeVault [this message]
2021-03-01 19:09 ` J. Bruce Fields
2021-03-01 19:35 ` Matthew Wilcox
2021-03-01 20:10 ` J. Bruce Fields
2021-03-02 8:24 ` Miklos Szeredi
2021-03-02 7:13 ` Amir Goldstein
2021-03-03 2:39 ` Aleksa Sarai
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