From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id n075rZXE007456 for ; Tue, 6 Jan 2009 23:53:38 -0600 Received: from mail.sandeen.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 92BB369754 for ; Tue, 6 Jan 2009 21:53:33 -0800 (PST) Received: from mail.sandeen.net (sandeen.net [209.173.210.139]) by cuda.sgi.com with ESMTP id VWmprNRMHRm1mkow for ; Tue, 06 Jan 2009 21:53:33 -0800 (PST) Message-ID: <4964435C.802@sandeen.net> Date: Tue, 06 Jan 2009 23:53:32 -0600 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: [PATCH] fix corruption case for block size < page size References: <49435F35.40109@sandeen.net> <4943FCD7.2010509@sandeen.net> <494735D9.8020809@sgi.com> <49473F5C.3070308@sandeen.net> <49474530.2080809@sgi.com> <4947466D.7000705@sandeen.net> <494748FA.20404@sandeen.net> <49474FE4.2030500@sandeen.net> <49643C5A.30608@sgi.com> In-Reply-To: <49643C5A.30608@sgi.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: lachlan@sgi.com Cc: xfs-oss Lachlan McIlroy wrote: > Eric Sandeen wrote: >> Eric Sandeen wrote: >> >>> Gah; or not. what is going on here... Doing just steps 1, 2, 3, 4 >>> (ending on the extending truncate): >>> >>> # xfs_io -c "pwrite -S 0x11 -b 4096 0 4096" -c "mmap -r 0 512" -c "mread >>> 0 512" -c "munmap" -c "truncate 256" -c "truncate 514" -t -d -f >>> /mnt/scratch/testfile >>> >>> # xfs_bmap -v /mnt/scratch/testfile >>> /mnt/scratch/testfile: >>> EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL >>> 0: [0..0]: 63..63 0 (63..63) 1 >>> 1: [1..1]: hole 1 >>> >>> It looks like what I expect, at this point. But then: >>> >>> # sync >>> # xfs_bmap -v /mnt/scratch/testfile >>> /mnt/scratch/testfile: >>> EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL >>> 0: [0..1]: 63..64 0 (63..64) 2 >>> >>> Um, why'd that last block get mapped in? mmap vs. direct IO I'm >>> guessing... w/o the mmap read this does not happen. >> Replying to myself twice? I really need to go to bed. >> >> So this all does seem to come back to page_state_convert. >> >> Both the extending write in the original case and the sync above find >> their way there; but esp. in the sync test above, why do we have *any* >> work to do? > Eric, did you find out why sync was allocating that second block? I'm afraid this has been on the back burner (or maybe further back) for a while... so... either "no" or "I don't remember" :) -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs