linux-ext4 - Re: [RFC] delayed allocation for ext4

lists.openwall.net		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 linux-cve-announce 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:	Sat, 23 Dec 2006 22:09:57 +0300
From:	Alex Tomas <alex@...sterfs.com>
To:	David Chinner <dgc@....com>
Cc:	Alex Tomas <alex@...sterfs.com>, linux-ext4@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC] delayed allocation for ext4

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.

 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.

 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?

thanks, Alex
-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html