Date: Tue, 31 Jul 2018 19:02:53 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 230220] UFS: the freezing ioctl (i.e.UFSSUSPEND) causes panic or EBUSY Message-ID: <bug-230220-227-eZCQGETGAM@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-230220-227@https.bugs.freebsd.org/bugzilla/> References: <bug-230220-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D230220 --- Comment #9 from Dexuan Cui <decui@microsoft.com> --- Thanks for the patch that removes the KASSERT for the panic! I still don't know how to correctly freeze all the mounted file systems. Can you please elaborate it? I do have multiple mounted file systems. My purpos= e is that:=20 1. Freeze all the mounted file systems, so any write access is suspended; 2. The host (i.e. Hyper-V) can take a quick snapshot of the guest image. The snapshot is file system consistent. 3. The guest can thaw the file systems, so any suspended write can resume. Assuming I have these 3 mounted file systems, should I freeze (and then tha= w) all of them? What order should I use -- freezing /mnt and /opt before / ? /dev/da0s1a on / (ufs, local, journaled soft-updates) /dev/da2p1 on /mnt (ufs, local, soft-updates) /dev/da2p2 on /opt (ufs, local, soft-updates) What' the correct way to thaw all the file systems -- by just closing the /dev/ufssuspend file descriptor, or callling ioctl(g_ufs_suspend_handle, UFSRESUME, ...) for every mounted file systems I froze by ioctl(g_ufs_suspend_handle, UFSSUSPEND, ...) ? According to https://lists.freebsd.org/pipermail/freebsd-fs/2015-February/020805.html, it looks I should use ioctl with UFSSUSPEND and UFSRESUME, but I need to figure out why contrib/hyperv/tools/hv_vss_daemon.c didn't do that in the first place. It looks there is no good document about how the UFSSUSPEND/UFSRESUME ioctl should be correctly used.=20 Linux has a utility fsfreeze: https://linux.die.net/man/8/fsfreeze, but it looks the equivalent utility doesn't exist in FreeBSD. --=20 You are receiving this mail because: You are the assignee for the bug.=
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