From: "Serge E. Hallyn" <serue@us.ibm.com>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>,
containers <containers@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Oren Laadan <orenl@cs.columbia.edu>,
Alexey Dobriyan <adobriyan@gmail.com>
Subject: Re: [RFC][PATCH 3/5] check files for checkpointability
Date: Mon, 23 Feb 2009 17:49:11 -0600 [thread overview]
Message-ID: <20090223234911.GB2590@us.ibm.com> (raw)
In-Reply-To: <20090219182009.1A3E8860@kernel>
Quoting Dave Hansen (dave@linux.vnet.ibm.com):
>
> Introduce a files_struct counter to indicate whether a particular
> file_struct has ever contained a file which can not be
> checkpointed. This flag is a one-way trip; once it is set, it may
> not be unset.
>
> We assume at allocation that a new files_struct is clean and may
> be checkpointed. However, as soon as it has had its files filled
> from its parent's, we check it for real in __scan_files_for_cr().
> At that point, we mark it if it contained any uncheckpointable
> files.
>
> We also check each 'struct file' when it is installed in a fd
> slot. This way, if anyone open()s or managed to dup() an
> unsuppored file, we can catch it.
So what is the point of tagging the files_struct counter and
making it a one-way trip? Why not just check every file at
checkpoint time?
-serge
next prev parent reply other threads:[~2009-02-23 23:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-19 18:20 [RFC][PATCH 1/5] create fs flag to mark c/r supported fs's Dave Hansen
2009-02-19 18:20 ` [RFC][PATCH 2/5] file c/r: expose functions to query fs support Dave Hansen
2009-02-19 18:20 ` [RFC][PATCH 3/5] check files for checkpointability Dave Hansen
2009-02-23 23:49 ` Serge E. Hallyn [this message]
2009-02-24 0:30 ` Dave Hansen
2009-02-24 1:10 ` Serge E. Hallyn
2009-02-24 1:20 ` Dave Hansen
2009-02-24 19:43 ` Serge E. Hallyn
2009-02-24 19:47 ` Dave Hansen
2009-02-19 18:20 ` [RFC][PATCH 4/5] breakout fdinfo sprintf() into its own function Dave Hansen
2009-02-19 18:20 ` [RFC][PATCH 5/5] add c/r info to fdinfo Dave Hansen
2009-02-19 18:23 ` [RFC][PATCH 1/5] create fs flag to mark c/r supported fs's Dave Hansen
2009-02-19 19:00 ` Christoph Hellwig
2009-02-19 19:24 ` Dave Hansen
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