Date: Sun, 16 Dec 2001 14:43:50 -0500 From: Jake Burkholder <jake@locore.ca> To: freebsd-alpha@FreeBSD.ORG Subject: Re: HEADS UP Re: cvs commit: src/sys/ufs/ffs ffs_alloc.c ffs_snapshot.c ffs_vfsops.c fs.h Message-ID: <20011216144350.B39205@locore.ca> In-Reply-To: <20011216000821.D35198@locore.ca>; from jake@locore.ca on Sun, Dec 16, 2001 at 12:08:21AM -0500 References: <200112140015.fBE0F6Q99440@freefall.freebsd.org> <20011216000821.D35198@locore.ca>
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Apparently, On Sun, Dec 16, 2001 at 12:08:21AM -0500, Jake Burkholder said words to the effect of; > > 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. This is fixed in rev 1.25 of fs.h. Jake > > 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 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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