Date: Tue, 02 Mar 2021 09:57:46 +0000 From: bugzilla-noreply@freebsd.org To: fs@FreeBSD.org Subject: [Bug 244048] mksnap_ffs hangs machine (12.1 regression over 11.3) Message-ID: <bug-244048-3630-uaujgD5DRx@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-244048-3630@https.bugs.freebsd.org/bugzilla/> References: <bug-244048-3630@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D244048 --- Comment #14 from ml@netfence.it --- I apologize for not being clear. The problem is not deterministic: behaviour changes slightly from machine to machine and even subsequent runs starting from the same VM snapshot can dif= fer. In comment 12 I was talking about the last situation I was able to achieve = that I think is interesting. VirtualBox VM with two disk: _ ada0 is the "system" disk (UFS SU+J); _ ada1 is the "data" disk, i.e. the one I'm trying snapshots on (GELI+UFS S= U, no journal as it would prevent snapshotting). The filesystem is clean: fsck finds no errors and everything works normally. There are already 12 snapshots. I can take one or two further snapshots (probably more, I didn't try): still everything is fine. However, if I *delete* an existing snapshot, trouble starts: _ subsequent mksnap_ffs produces the deadlock I described; _ trying to unmount the filesystem also hangs (but won't hang the whole machine): ctrl-t may say it's in "secwr", like the above or in "bo_wwait" o= r in "wdrain"; a LOR (ufs@vfs_mount.c:1349/devfs@ffs_vfsops.c:1610) may appear or not; _ even shutdown doesn't work properly: vnodes remaining count seems to rise= and decrease at the same time; it may reach 0, but will grow again. What happens after an hard reset can vary: fsck -p in single user mode seem= s to work and recover the situation; a background fsck is usually asking for troubles, often resulting in a panic (dropping into DDB). In the end I was perhaps looking at the wrong side of things: it might not = be mksnap_ffs that hangs the machine, but *deleting* a snapshot. I'm not sure, though: I think in the past I've seen situations where it han= ged even without deleting, but I cannot reconstruct now. Unfortunately https://reviews.freebsd.org/D28901 doesn't seem to help. Next thing I'll do is try 13.0 (unless someone has a better suggestion). --=20 You are receiving this mail because: You are the assignee for the bug.=
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