From: Maxim Patlasov <mpatlasov@parallels.com>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: <dev@parallels.com>, <xemul@parallels.com>,
<fuse-devel@lists.sourceforge.net>, <bfoster@redhat.com>,
<linux-kernel@vger.kernel.org>, <jbottomley@parallels.com>,
<linux-fsdevel@vger.kernel.org>, <akpm@linux-foundation.org>,
<fengguang.wu@intel.com>, <devel@openvz.org>
Subject: Re: [PATCH 05/11] fuse: Trust kernel i_mtime only -v2
Date: Mon, 20 Jan 2014 15:33:37 +0400 [thread overview]
Message-ID: <52DD0991.2000905@parallels.com> (raw)
In-Reply-To: <20140106162242.GE16230@tucsk.piliscsaba.szeredi.hu>
On 01/06/2014 08:22 PM, Miklos Szeredi wrote:
> On Thu, Dec 26, 2013 at 07:41:41PM +0400, Maxim Patlasov wrote:
>>>> +
>>>> + if (!err)
>>>> + clear_bit(FUSE_I_MTIME_DIRTY, &fi->state);
>>> Doing the test and the clear separately opens a huge race window when i_mtime
>>> modifications are bound to get lost.
>> No. Because the whole operation is protected by i_mutex (see
>> fuse_fsync_common()).
> fuse_release_common() doesn't have i_mutex. It's probably safe to acquire it,
> but is that really needed?
No, that's not needed, I think. Because by the time of calling
fuse_release(), file->f_count is already zero and no userspace activity
is possible on the file.
Are you OK about -v3 version of the patch (sent 12/26/2013)?
Thanks,
Maxim
>
> Thanks,
> Miklos
>
next prev parent reply other threads:[~2014-01-20 11:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-10 13:09 [PATCH v6 00/11] fuse: An attempt to implement a write-back cache policy Maxim Patlasov
2013-10-10 13:10 ` [PATCH 01/11] fuse: Linking file to inode helper Maxim Patlasov
2013-10-10 13:10 ` [PATCH 02/11] fuse: Prepare to handle short reads Maxim Patlasov
2013-10-10 13:10 ` [PATCH 03/11] fuse: Connection bit for enabling writeback Maxim Patlasov
2013-10-10 13:10 ` [PATCH 04/11] fuse: Trust kernel i_size only - v4 Maxim Patlasov
[not found] ` <20131010130718.10089.6736.stgit-opBMJL+S1+lZ2WjqXT1pg9yJl3JzOD/t@public.gmane.org>
2013-10-10 13:10 ` [PATCH 05/11] fuse: Trust kernel i_mtime only -v2 Maxim Patlasov
2013-11-12 16:52 ` Miklos Szeredi
2013-12-26 15:41 ` Maxim Patlasov
2014-01-06 16:22 ` Miklos Szeredi
2014-01-20 11:33 ` Maxim Patlasov [this message]
2013-12-26 15:51 ` [PATCH 05/11] fuse: Trust kernel i_mtime only -v3 Maxim Patlasov
2013-10-10 13:11 ` [PATCH 06/11] fuse: Flush files on wb close -v2 Maxim Patlasov
[not found] ` <20131010131102.10089.51081.stgit-opBMJL+S1+lZ2WjqXT1pg9yJl3JzOD/t@public.gmane.org>
2013-10-10 13:19 ` [PATCH] " Maxim Patlasov
2013-10-10 13:11 ` [PATCH 07/11] fuse: restructure fuse_readpage() Maxim Patlasov
2013-11-12 17:17 ` Miklos Szeredi
2013-12-20 14:54 ` Maxim Patlasov
2014-01-06 16:43 ` Miklos Szeredi
2014-01-20 11:46 ` Maxim Patlasov
2013-10-10 13:11 ` [PATCH 08/11] fuse: Implement write_begin/write_end callbacks -v2 Maxim Patlasov
2013-10-10 13:11 ` [PATCH 09/11] fuse: fuse_flush() should wait on writeback Maxim Patlasov
2013-10-10 13:12 ` [PATCH 10/11] fuse: Fix O_DIRECT operations vs cached writeback misorder - v2 Maxim Patlasov
2013-10-10 13:12 ` [PATCH 11/11] fuse: Turn writeback cache on Maxim Patlasov
[not found] ` <87li13pido.fsf@vostro.rath.org>
[not found] ` <CAJfpegvFFXPuEoXXXJCBLEQi+T3mx95g4X+MjxAbyg0rhjbfDA@mail.gmail.com>
[not found] ` <528321C3.20307@parallels.com>
[not found] ` <CAJfpegu_ScgdgHDVM_5GMQC86OFnpXLDsuArKbWP_cX-D8m8Jw@mail.gmail.com>
[not found] ` <52FA4ECD.2030608@parallels.com>
[not found] ` <52FC2DE5.9010008@rath.org>
[not found] ` <52FCB029.9040608@parallels.com>
[not found] ` <87wqgwdvi1.fsf@vostro.rath.org>
2014-02-27 15:33 ` fuse write performance Miklos Szeredi
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