From owner-freebsd-alpha Sat Dec 15 21: 6:14 2001 Delivered-To: freebsd-alpha@freebsd.org Received: from k6.locore.ca (k6.locore.ca [198.96.117.170]) by hub.freebsd.org (Postfix) with ESMTP id C048D37B417 for ; Sat, 15 Dec 2001 21:06:03 -0800 (PST) Received: (from jake@localhost) by k6.locore.ca (8.11.6/8.11.6) id fBG58LY36694 for freebsd-alpha@freebsd.org; Sun, 16 Dec 2001 00:08:21 -0500 (EST) (envelope-from jake) Date: Sun, 16 Dec 2001 00:08:21 -0500 From: Jake Burkholder To: freebsd-alpha@freebsd.org Subject: HEADS UP Re: cvs commit: src/sys/ufs/ffs ffs_alloc.c ffs_snapshot.c ffs_vfsops.c fs.h Message-ID: <20011216000821.D35198@locore.ca> References: <200112140015.fBE0F6Q99440@freefall.freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200112140015.fBE0F6Q99440@freefall.freebsd.org>; from mckusick@FreeBSD.org on Thu, Dec 13, 2001 at 04:15:06PM -0800 Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org This commit breaks binary compatibility of the ffs superblock for 64 bit platforms. Do not update to -current or you will not be able to mount your ffs filesystems (unless you use kernel.old). Have a nice day. Apparently, On Thu, Dec 13, 2001 at 04:15:06PM -0800, Kirk McKusick said words to the effect of; > mckusick 2001/12/13 16:15:06 PST > > Modified files: > sys/ufs/ffs ffs_alloc.c ffs_snapshot.c ffs_vfsops.c > fs.h > Log: > Minimize the time necessary to suspend operations on a filesystem > when taking a snapshot. The two time consuming operations are > scanning all the filesystem bitmaps to determine which blocks > are in use and scanning all the other snapshots so as to be able > to expunge their blocks from the view of the current snapshot. > The bitmap scanning is broken into two passes. Before suspending > the filesystem all bitmaps are scanned. After the suspension, > those bitmaps that changed after being scanned the first time > are rescanned. Typically there are few bitmaps that need to be > rescanned. The expunging of other snapshots is now done after > the suspension is released by observing that we can easily > identify any blocks that were allocated to them after the > suspension (they will be maked as `not needing to be copied' > in the just created snapshot). For all the gory details, see > the ``Running fsck in the Background'' paper in the Usenix > BSDCon 2002 Conference Proceedings, pages 55-64. > > Revision Changes Path > 1.82 +15 -1 src/sys/ufs/ffs/ffs_alloc.c > 1.24 +193 -96 src/sys/ufs/ffs/ffs_snapshot.c > 1.164 +1 -0 src/sys/ufs/ffs/ffs_vfsops.c > 1.24 +3 -2 src/sys/ufs/ffs/fs.h To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message