From: Greg Freemyer Subject: Re: [RFC][PATCH 1/7]ext4: Add EXT4_IOC_ADD_GLOBAL_ALLOC_RULE restricts block allocation Date: Thu, 25 Jun 2009 08:47:59 -0400 Message-ID: <87f94c370906250547l338fd357s2e51291185bc3b2c@mail.gmail.com> References: <4A409168.3020404@rs.jp.nec.com> <20090623231950.GN31668@webber.adilger.int> <87f94c370906231702m6dde1402o9d2738f97f4b7df9@mail.gmail.com> <20090624001158.GQ31668@webber.adilger.int> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Akira Fujita , linux-ext4@vger.kernel.org, "Theodore Ts'o" , linux-fsdevel@vger.kernel.org, Aneesh Kumar To: Andreas Dilger Return-path: In-Reply-To: <20090624001158.GQ31668@webber.adilger.int> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Aneesh, Can you provide the below requested info? Thanks Greg On Tue, Jun 23, 2009 at 8:11 PM, Andreas Dilger wrote: > On Jun 23, 2009 =A020:02 -0400, Greg Freemyer wrote: >> On Tue, Jun 23, 2009 at 7:19 PM, Andreas Dilger wro= te: >> > On Jun 23, 2009 =A017:25 +0900, Akira Fujita wrote: >> >> alloc_flag of ext4_alloc_rule structure is set as "mandatory" or = "advisory". >> >> Restricted blocks with "mandatory" are never used by block alloca= tor. >> >> But in "advisory" case, block allocator is allowed to use restric= ted blocks >> >> when there are no free blocks on FS. >> > >> > Would it make more sense to implement the range protections via th= e >> > existing preallocation ranges (PA)? =A0An inode can have multiple >> > PAs attached to it to have it prefer allocations from that range. >> > >> > We could also attach PAs to the superblock to prevent other files = from >> > allocating out of those ranges. =A0This would work better with the= existing >> > allocation code instead of creating a second similar mechanism. >> >> Where can I find documentation about how PA works? =A0Or is it just = in >> the source? =A0If so, what are one or two calls that cause the PA ra= nges >> to be set, etc. > > Aneesh is the expert on the preallocation code. > > Cheers, Andreas > -- > Andreas Dilger > Sr. Staff Engineer, Lustre Group > Sun Microsystems of Canada, Inc. > > --=20 Greg Freemyer Head of EDD Tape Extraction and Processing team Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer Preservation and Forensic processing of Exchange Repositories White Pap= er - http://www.norcrossgroup.com/forms/whitepapers/Forensic%20Processing%20= of%20Exchange%20WP%20final.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html