From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC] a corner case of open(2)
Date: Tue, 26 Apr 2016 18:55:38 +0100 [thread overview]
Message-ID: <20160426175538.GO25498@ZenIV.linux.org.uk> (raw)
According to POSIX (and behaviour on other Unices) the following
should succeed: open("/tmp", O_CREAT, 0) does not have O_EXCL and the pathname
does refer to existing object, so O_CREAT is ignored and the call is
equivalent to open("/tmp", 0), which succeeds.
We have it rejected with EISDIR. The thing is, the standard behaviour
is actually less messy wrt code, and do_last()/lookup_open()/atomic_open()
badly needs untangling.
Another place where we produce a bogus EISDIR is O_CREAT|O_EXCL on
an existing directory. POSIX (and other Unices) have EEXIST there. In some
cases we produce EEXIST, in some - EISDIR. Uniform EEXIST is actually easier.
It is a change of user-visible behaviour, but I would be very
surprised if anything broke from that change. And it would help to simplify
the awful mess we have in there.
Comments?
next reply other threads:[~2016-04-26 17:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-26 17:55 Al Viro [this message]
2016-04-26 18:05 ` [RFC] a corner case of open(2) Cedric Blancher
2016-04-26 18:15 ` Al Viro
2016-04-26 18:41 ` Valdis.Kletnieks
2016-04-26 19:02 ` Al Viro
2016-04-26 19:25 ` Valdis.Kletnieks
2016-04-26 20:17 ` Al Viro
2016-04-27 5:34 ` Al Viro
2016-04-27 9:33 ` Miklos Szeredi
2016-04-27 19:29 ` another patch in #for-linus (was Re: [RFC] a corner case of open(2)) Al Viro
2016-05-02 21:48 ` Pavel Machek
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