OpenVZ Forum: Devel » Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction

Home » Mailing lists » Devel » Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction [message #7365 is a reply to message #7361]

Thu, 12 October 2006 07:01

Nick Piggin
Messages: 35
Registered: March 2006

Member

Andrew Morton wrote:
> On Thu, 12 Oct 2006 09:57:26 +0400
> Dmitriy Monakhov <dmonakhov@openvz.org> wrote:
>
>
>>While reading Andrew's generic_file_buffered_write patches i've remembered
>>one more EXT3 issue.journal_start() in prepare_write() causes different ranking
>>violations if copy_from_user() triggers a page fault. It could cause
>>GFP_FS allocation, re-entering into ext3 code possibly with a different
>>superblock and journal, ranking violation of journalling serialization
>>and mmap_sem and page lock and all other kinds of funny consequences.
>
>
> With the stuff Nick and I are looking at, we won't take pagefaults inside
> prepare_write()/commit_write() any more.

Yep. Because the page is locked, it is too much to deal with even
without a filesystem in the picture.

--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com

Report message to a moderator

[Message index]

		Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction By: Andrew Morton on Thu, 12 October 2006 06:43
		Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction By: Nick Piggin on Thu, 12 October 2006 07:01
		Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction By: Dmitriy Monakhov on Thu, 12 October 2006 07:53
		Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction By: Andrew Morton on Thu, 12 October 2006 08:37
		Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction By: Nick Piggin on Thu, 12 October 2006 08:31

Previous Topic:	[RFC][PATCH] EXT3: problem with page fault inside a transaction
Next Topic:	IMPORTANT: latest RHEL4 kernel has a root exploit!! (2.6.9-023stab016.2)

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Mon Jul 21 05:09:37 GMT 2025

Total time taken to generate the page: 0.07919 seconds