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From: Rik van Riel <riel@redhat.com>
To: Boaz Harrosh <boaz@plexistor.com>,
	Daniel Phillips <daniel@phunq.net>,
	linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, tux3@tux3.org,
	OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Subject: Re: [FYI] tux3: Core changes
Date: Sun, 17 May 2015 22:20:58 -0400	[thread overview]
Message-ID: <55594C8A.7000803@redhat.com> (raw)
In-Reply-To: <555896EB.7040002@plexistor.com>

On 05/17/2015 09:26 AM, Boaz Harrosh wrote:
> On 05/14/2015 03:59 PM, Rik van Riel wrote:
>> On 05/14/2015 04:26 AM, Daniel Phillips wrote:
>>> Hi Rik,
> <>
>>
>> The issue is that things like ptrace, AIO, infiniband
>> RDMA, and other direct memory access subsystems can take
>> a reference to page A, which Tux3 clones into a new page B
>> when the process writes it.
>>
>> However, while the process now points at page B, ptrace,
>> AIO, infiniband, etc will still be pointing at page A.
>>
> 
> All these problems can also happen with truncate+new-extending-write
> 
> It is the responsibility of the application to take file/range locks
> to prevent these page-pinned problems.

It is unreasonable to expect a process that is being ptraced
(potentially without its knowledge) to take special measures
to protect the ptraced memory from disappearing.

It is impossible for the debugger to take those special measures
for anonymous memory, or unlinked inodes.

I don't think your requirement is workable or reasonable.

-- 
All rights reversed

  reply	other threads:[~2015-05-18  2:20 UTC|newest]

Thread overview: 160+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-28 23:13 Tux3 Report: How fast can we fsync? Daniel Phillips
2015-04-29  2:21 ` Mike Galbraith
2015-04-29  6:01   ` Daniel Phillips
2015-04-29  6:20     ` Richard Weinberger
2015-04-29  6:56       ` Daniel Phillips
2015-04-29  6:33     ` Mike Galbraith
2015-04-29  7:23       ` Daniel Phillips
2015-04-29 16:42         ` Mike Galbraith
2015-04-29 19:05           ` xfs: does mkfs.xfs require fancy switches to get decent performance? (was Tux3 Report: How fast can we fsync?) Mike Galbraith
2015-04-29 19:20             ` Austin S Hemmelgarn
2015-04-29 21:12             ` Daniel Phillips
2015-04-30  4:40               ` Mike Galbraith
2015-04-30  0:20             ` Dave Chinner
2015-04-30  3:35               ` Mike Galbraith
2015-04-30  9:00               ` Martin Steigerwald
2015-04-30 14:57                 ` Theodore Ts'o
2015-04-30 15:59                   ` Daniel Phillips
2015-04-30 17:59                   ` Martin Steigerwald
2015-04-30 11:14               ` Daniel Phillips
2015-04-30 12:07                 ` Mike Galbraith
2015-04-30 12:58                   ` Daniel Phillips
2015-04-30 13:48                     ` Mike Galbraith
2015-04-30 14:07                       ` Daniel Phillips
2015-04-30 14:28                         ` Howard Chu
2015-04-30 15:14                           ` Daniel Phillips
2015-04-30 16:00                             ` Howard Chu
2015-04-30 18:22                             ` Christian Stroetmann
2015-05-11 22:12                             ` Pavel Machek
2015-05-11 23:17                               ` Theodore Ts'o
2015-05-12  2:34                                 ` Daniel Phillips
2015-05-12  5:38                                   ` Dave Chinner
2015-05-12  6:18                                     ` Daniel Phillips
2015-05-12 18:39                                       ` David Lang
2015-05-12 20:54                                         ` Daniel Phillips
2015-05-12 21:30                                           ` David Lang
2015-05-12 22:27                                             ` Daniel Phillips
2015-05-12 22:35                                               ` David Lang
2015-05-12 23:55                                                 ` Theodore Ts'o
2015-05-13  1:26                                                 ` Daniel Phillips
2015-05-13 19:09                                                   ` Martin Steigerwald
2015-05-13 19:37                                                     ` Daniel Phillips
2015-05-13 20:02                                                       ` Jeremy Allison
2015-05-13 20:24                                                         ` Daniel Phillips
2015-05-13 20:25                                                       ` Martin Steigerwald
2015-05-13 20:38                                                         ` Daniel Phillips
2015-05-13 21:10                                                           ` Martin Steigerwald
2015-05-13  0:31                                             ` Daniel Phillips
2015-05-12 21:30                                           ` Christian Stroetmann
2015-05-13  7:20                                           ` Pavel Machek
2015-05-13 13:47                                             ` Elifarley Callado Coelho Cruz
2015-05-12  9:03                                   ` Pavel Machek
2015-05-12 11:22                                     ` Daniel Phillips
2015-05-12 13:26                                       ` Howard Chu
2015-05-11 23:53                               ` Daniel Phillips
2015-05-12  0:12                                 ` David Lang
2015-05-12  4:36                                   ` Daniel Phillips
2015-05-12 17:30                                     ` Christian Stroetmann
2015-05-13  7:25                                 ` Pavel Machek
2015-05-13 11:31                                   ` Daniel Phillips
2015-05-13 12:41                                     ` Daniel Phillips
2015-05-13 13:08                                     ` Mike Galbraith
2015-05-13 13:15                                       ` Daniel Phillips
2015-04-30 14:33                         ` Mike Galbraith
2015-04-30 15:24                           ` Daniel Phillips
2015-04-29 20:40           ` Tux3 Report: How fast can we fsync? Daniel Phillips
2015-04-29 22:06             ` OGAWA Hirofumi
2015-04-30  3:57               ` Mike Galbraith
2015-04-30  3:50             ` Mike Galbraith
2015-04-30 10:59               ` Daniel Phillips
2015-04-30  1:46 ` Dave Chinner
2015-04-30 10:28   ` Daniel Phillips
2015-05-01 15:38     ` Dave Chinner
2015-05-01 23:20       ` Daniel Phillips
2015-05-02  1:07         ` David Lang
2015-05-02 10:26           ` Daniel Phillips
2015-05-02 16:00             ` Christian Stroetmann
2015-05-02 16:30               ` Richard Weinberger
2015-05-02 17:00                 ` Christian Stroetmann
2015-05-12 17:41 ` Daniel Phillips
2015-05-12 17:46 ` Tux3 Report: How fast can we fail? Daniel Phillips
2015-05-13 22:07   ` Daniel Phillips
2015-05-26 10:03   ` Pavel Machek
2015-05-27  6:41     ` Mosis Tembo
2015-05-27 18:28       ` Daniel Phillips
2015-05-27 21:39         ` Pavel Machek
2015-05-27 22:46           ` Daniel Phillips
2015-05-28 12:55             ` Austin S Hemmelgarn
2015-05-27  7:37     ` Mosis Tembo
2015-05-27 14:04       ` Austin S Hemmelgarn
2015-05-27 15:21         ` Mosis Tembo
2015-05-27 15:37           ` Austin S Hemmelgarn
2015-05-14  7:37 ` [WIP] tux3: Optimized fsync Daniel Phillips
2015-05-14  8:26 ` [FYI] tux3: Core changes Daniel Phillips
2015-05-14 12:59   ` Rik van Riel
2015-05-15  0:06     ` Daniel Phillips
2015-05-15  3:06       ` Rik van Riel
2015-05-15  8:09         ` Mel Gorman
2015-05-15  9:54           ` Daniel Phillips
2015-05-15 11:00             ` Mel Gorman
2015-05-16 22:38               ` David Lang
2015-05-18 12:57                 ` Mel Gorman
2015-05-15  9:38         ` Daniel Phillips
2015-05-27  7:41           ` Pavel Machek
2015-05-27 18:09             ` Daniel Phillips
2015-05-27 21:37               ` Pavel Machek
2015-05-27 22:33                 ` Daniel Phillips
2015-05-15  8:05       ` Mel Gorman
2015-05-17 13:26     ` Boaz Harrosh
2015-05-18  2:20       ` Rik van Riel [this message]
2015-05-18  7:58         ` Boaz Harrosh
2015-05-19  4:46         ` Daniel Phillips
2015-05-21 19:43     ` [WIP][PATCH] tux3: preliminatry nospace handling Daniel Phillips
2015-05-19 14:00   ` [FYI] tux3: Core changes Jan Kara
2015-05-19 19:18     ` Daniel Phillips
2015-05-19 20:33       ` David Lang
2015-05-20 14:44         ` Jan Kara
2015-05-20 16:22           ` Daniel Phillips
2015-05-20 18:01             ` David Lang
2015-05-20 19:53             ` Rik van Riel
2015-05-20 22:51               ` Daniel Phillips
2015-05-21  3:24                 ` Daniel Phillips
2015-05-21  3:51                   ` David Lang
2015-05-21 19:53                     ` Daniel Phillips
2015-05-26  4:25                       ` Rik van Riel
2015-05-26  4:30                         ` Daniel Phillips
2015-05-26  6:04                           ` David Lang
2015-05-26  6:11                             ` Daniel Phillips
2015-05-26  6:13                               ` David Lang
2015-05-26  8:09                                 ` Daniel Phillips
2015-05-26 10:13                                   ` Pavel Machek
2015-05-26  7:09                               ` Jan Kara
2015-05-26  8:08                                 ` Daniel Phillips
2015-05-26  9:00                                   ` Jan Kara
2015-05-26 20:22                                     ` Daniel Phillips
2015-05-26 21:36                                       ` Rik van Riel
2015-05-26 21:49                                         ` Daniel Phillips
2015-05-27  8:41                                       ` Jan Kara
2015-06-21 15:36                                         ` OGAWA Hirofumi
2015-06-23 16:12                                           ` Jan Kara
2015-07-05 12:54                                             ` OGAWA Hirofumi
2015-07-09 16:05                                               ` Jan Kara
2015-07-31  4:44                                                 ` OGAWA Hirofumi
2015-07-31 15:37                                                   ` Raymond Jennings
2015-07-31 17:27                                                     ` Daniel Phillips
2015-07-31 18:29                                                       ` David Lang
2015-07-31 18:43                                                         ` Daniel Phillips
2015-07-31 22:12                                                         ` Daniel Phillips
2015-07-31 22:27                                                           ` David Lang
2015-08-01  0:00                                                             ` Daniel Phillips
2015-08-01  0:16                                                               ` Daniel Phillips
2015-08-03 13:07                                                                 ` Jan Kara
2015-08-01 10:55                                                             ` Elifarley Callado Coelho Cruz
2015-08-18 16:39                                                       ` Rik van Riel
2015-08-03 13:42                                                   ` Jan Kara
2015-08-09 13:42                                                     ` OGAWA Hirofumi
2015-08-10 12:45                                                       ` Jan Kara
2015-08-16 19:42                                                         ` OGAWA Hirofumi
2015-05-26 10:22                                   ` Sergey Senozhatsky
2015-05-26 12:33                                     ` Jan Kara
2015-05-26 19:18                                     ` Daniel Phillips

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