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From: Daniel Lezcano <daniel.lezcano@free.fr>
To: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Jamie Lokier <jamie@shareable.org>,
	linux-fsdevel@vger.kernel.org,
	containers@lists.linux-foundation.org,
	Andreas Dilger <adilger@sun.com>
Subject: Re: [C/R v20][PATCH 38/96] c/r: dump open file descriptors
Date: Sun, 21 Mar 2010 21:58:44 +0100	[thread overview]
Message-ID: <4BA68884.3080003@free.fr> (raw)
In-Reply-To: <20100321194019.GA11714@hallyn.com>

Serge E. Hallyn wrote:
> Quoting Jamie Lokier (jamie@shareable.org):
>   
>> Matt Helsley wrote:
>>     
>>>> That said, if the intent is to allow the restore to be done on
>>>> another node with a "similar" filesystem (e.g. created by rsync/node
>>>> image), instead of having a coherent distributed filesystem on all
>>>> of the nodes then the filename makes sense.
>>>>         
>>> Yes, this is the intent.
>>>       
>> I would worry about programs which are using files which have been
>> deleted, renamed, or (very common) renamed-over by another process
>> after being opened, as there's a good chance they will successfully
>> open the wrong file after c/r, and corrupt state from then on.
>>     
>
> Userspace is expected to back up and restore the filesystem, for
> instance using a btrfs snapshot or a simple rsync or tar.
>
>   
That does not solve the problem Jamie is talking about.
A rsync or a tar will not see a deleted file and using a btrfs to have 
the CR to work with the deleted files is a bit overkill, no ?
I have another question about the deleted files. How is handled the case 
when a process has a deleted mapped file but without an associated file 
descriptor ?

> If we detect anything which really is not supported (for instance
> inotify for now) then we fail and leave a log message explaining the
> failure.
>   


  reply	other threads:[~2010-03-21 20:58 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-19  0:59 [C/R v20][PATCH 00/96] Linux Checkpoint-Restart - v20 Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 20/96] c/r: make file_pos_read/write() public Oren Laadan
2010-03-22  6:31   ` Nick Piggin
2010-03-23  0:12     ` Oren Laadan
2010-03-23  0:43       ` Nick Piggin
2010-03-23  0:56         ` Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 37/96] c/r: introduce new 'file_operations': ->checkpoint, ->collect() Oren Laadan
2010-03-22  6:34   ` Nick Piggin
2010-03-22 10:16     ` Matt Helsley
2010-03-22 11:00       ` Nick Piggin
2010-03-19  0:59 ` [C/R v20][PATCH 38/96] c/r: dump open file descriptors Oren Laadan
2010-03-19 23:19   ` Andreas Dilger
2010-03-20  4:43     ` Matt Helsley
2010-03-21 17:27       ` Jamie Lokier
2010-03-21 19:40         ` Serge E. Hallyn
2010-03-21 20:58           ` Daniel Lezcano [this message]
2010-03-21 21:36             ` Oren Laadan
     [not found]               ` <4BA6914D.8040007-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-03-21 23:31                 ` xing lin
2010-03-22  8:40               ` Daniel Lezcano
2010-03-22  2:12             ` Matt Helsley
2010-03-22 13:51               ` Jamie Lokier
2010-03-22 23:18               ` Andreas Dilger
2010-03-22  1:06         ` Matt Helsley
2010-03-22  2:20           ` Jamie Lokier
2010-03-22  3:37             ` Matt Helsley
2010-03-22 14:13               ` Jamie Lokier
2010-03-22  2:55           ` Serge E. Hallyn
     [not found]   ` <1268960401-16680-4-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-03-22 10:30     ` Nick Piggin
2010-03-22 13:22       ` Matt Helsley
2010-03-22 13:38         ` Nick Piggin
2010-03-19  0:59 ` [C/R v20][PATCH 39/96] c/r: restore " Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 40/96] c/r: introduce method '->checkpoint()' in struct vm_operations_struct Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 44/96] c/r: add generic '->checkpoint' f_op to ext fses Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 45/96] c/r: add generic '->checkpoint()' f_op to simple devices Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 50/96] splice: export pipe/file-to-pipe/file functionality Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 51/96] c/r: support for open pipes Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 52/96] c/r: checkpoint and restore FIFOs Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 53/96] c/r: refuse to checkpoint if monitoring directories with dnotify Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 66/96] c/r: restore file->f_cred Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 82/96] c/r: checkpoint/restart epoll sets Oren Laadan
2010-03-19  0:59 ` [C/R v20][PATCH 83/96] c/r: checkpoint/restart eventfd Oren Laadan
2010-03-19  1:00 ` [C/R v20][PATCH 84/96] c/r: restore task fs_root and pwd (v3) Oren Laadan
2010-03-19  1:00 ` [C/R v20][PATCH 85/96] c/r: preliminary support mounts namespace Oren Laadan

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