From: stsp <stsp2@yandex.ru>
To: Jeff Layton <jlayton@kernel.org>, linux-kernel@vger.kernel.org
Cc: Chuck Lever <chuck.lever@oracle.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 2/3] fd/locks: allow get the lock owner by F_OFD_GETLK
Date: Tue, 20 Jun 2023 17:34:00 +0500 [thread overview]
Message-ID: <d70b6831-3443-51d0-f64c-6f6996367a85@yandex.ru> (raw)
In-Reply-To: <2eb8566726e95a01536b61a3b8d0343379092b94.camel@kernel.org>
20.06.2023 17:02, Jeff Layton пишет:
> Suppose I start a process (call it pid 100), and then spawn a thread
> (101). I then have 101 open a file and set an OFD lock on it (such that
> the resulting fl_pid field in the file_lock is set to 101).
How come?
There are multiple places in locks.c
with this line:
fl->fl_pid = current->tgid;
And I've yet to see the line like:
fl->fl_pid = current->pid;
Its simply not there.
No, we put tgid into l_pid!
tgid will still be 100, no matter how
many threads you spawn or destroy.
Or what am I misseng?
> That's just one example, of course. The underlying problem is that OFD
> locks are not owned by processes in the same way that traditional POSIX
> locks are, so reporting a pid there is unreliable, at best.
But we report tgid.
It doesn't depend on threads.
I don't understand. :)
next prev parent reply other threads:[~2023-06-20 12:34 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 9:55 [PATCH 0/3] RFC: F_OFD_GETLK should provide more info Stas Sergeev
2023-06-20 9:55 ` [PATCH 1/3] fs/locks: F_UNLCK extension for F_OFD_GETLK Stas Sergeev
2023-06-20 10:46 ` Jeff Layton
2023-06-20 11:00 ` stsp
2023-06-20 11:15 ` Jeff Layton
2023-06-21 15:24 ` stsp
2023-06-20 9:55 ` [PATCH 2/3] fd/locks: allow get the lock owner by F_OFD_GETLK Stas Sergeev
2023-06-20 10:51 ` Jeff Layton
2023-06-20 10:57 ` stsp
2023-06-20 11:12 ` Jeff Layton
2023-06-20 11:45 ` stsp
2023-06-20 12:02 ` Jeff Layton
2023-06-20 12:34 ` stsp [this message]
2023-06-20 13:19 ` Jeff Layton
2023-06-20 13:39 ` stsp
2023-06-20 13:46 ` Matthew Wilcox
2023-06-20 13:47 ` stsp
2023-06-20 14:36 ` Matthew Wilcox
2023-06-20 15:45 ` stsp
2023-06-20 17:05 ` Matthew Wilcox
2023-06-21 2:54 ` stsp
2023-06-23 13:10 ` David Laight
2023-06-20 13:58 ` Jeff Layton
2023-06-21 6:57 ` stsp
2023-06-21 10:35 ` Jeff Layton
2023-06-21 10:42 ` stsp
2023-06-21 11:05 ` Jeff Layton
2023-06-21 11:22 ` stsp
2023-06-21 11:26 ` stsp
2023-06-23 15:25 ` Christian Brauner
2023-06-23 17:18 ` stsp
2023-06-27 16:00 ` Jeff Layton
2023-06-27 16:20 ` stsp
2023-06-20 9:55 ` [PATCH 3/3] selftests: add OFD lock tests Stas Sergeev
2023-06-20 11:06 ` Jeff Layton
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