lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 29 Dec 2006 13:52:46 +1100
From:	David Chinner <>
To:	Alex Tomas <>
Cc:	David Chinner <>,,
Subject: Re: [RFC] delayed allocation for ext4

On Sat, Dec 23, 2006 at 10:09:57PM +0300, Alex Tomas wrote:
> Good day,
> >>>>> David Chinner (DC) writes:
>  DC> So that mean's we'll have 2 separate mechanisms for marking
>  DC> pages as delalloc. XFS uses the BH_delay flag to indicate
>  DC> that a buffer (block) attached to the page is using delalloc.
> well, for blocksize=pagesize we can save 56 bytes on every page.

Sure, but it means that ext4 w/ delalloc won't work on lots of

>  DC> FWIW, how does this mechanism deal with block size < page size?
>  DC> Don't you have to track delalloc on a block basis rather than
>  DC> a page basis?
> I'm still thinking how better to deal with that w/o much code duplication.

Code duplication in ext4, or across all filesystems?

>  DC> Ah, that's why you can get away with a page flag - you've ignored
>  DC> the partial page delay state problem. Any plans to use the
>  DC> existing method in the future so we will be able to use ext4 delalloc
>  DC> on machines with a page size larger than 4k?
> what do you mean by "exsiting"? BH_delay?



Dave Chinner
Principal Engineer
SGI Australian Software Group
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists