Date: Sat, 23 May 2026 21:46:54 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 295532] lock order reversal zfs and ufs Message-ID: <bug-295532-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=295532 Bug ID: 295532 Summary: lock order reversal zfs and ufs Product: Base System Version: 16.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: jfc@mit.edu Today running 16-CURRENT in bhyve I had a lock order reversal with zfs and ufs named and nullfs implied. Given the stack trace and concurrent system activity, I figure poudriere was cleaning up its ZFS filesystems at the end of a build. The build filesystems had nullfs mounts leading back to UFS /usr/src. Root filesystem (UFS) includes /usr/src. Poudriere master filesystem (ZFS) has a nullfs mount of root filesystem /usr/src. Builder filesystem (ZFS) has a nullfs mount of master filesystem usr/src. But there are four null_lock calls in the stack trace, not three. I might have missed a filesystem. lock order reversal: 1st 0xfffff80c0f52d908 zfs (zfs, lockmgr) @ /usr/src/sys/kern/vfs_mount.c:2299 2nd 0xfffff80005a55c78 ufs (ufs, lockmgr) @ /usr/src/sys/fs/nullfs/null_vnops.c:851 lock order ufs -> zfs established at: #0 0xffffffff80c2f16b at witness_checkorder+0x35b #1 0xffffffff80b80f1a at lockmgr_lock_flags+0x16a #2 0xffffffff811db702 at VOP_LOCK1_APV+0x32 #3 0xffffffff80cd9123 at _vn_lock+0x53 #4 0xffffffff80cbeb19 at vflush+0xe9 #5 0xffffffff8305885a at zfs_umount+0xda #6 0xffffffff80cb28b4 at dounmount+0x664 #7 0xffffffff80cb21fc at kern_unmount+0x35c #8 0xffffffff8110ba08 at amd64_syscall+0x168 #9 0xffffffff810db0ab at fast_syscall_common+0xf8 lock order zfs -> ufs attempted at: #0 0xffffffff80c2faa7 at witness_checkorder+0xc97 #1 0xffffffff80b80f1a at lockmgr_lock_flags+0x16a #2 0xffffffff80f615fd at ffs_lock+0x8d #3 0xffffffff811db702 at VOP_LOCK1_APV+0x32 #4 0xffffffff82e89229 at null_lock+0x169 #5 0xffffffff811db702 at VOP_LOCK1_APV+0x32 #6 0xffffffff82e89229 at null_lock+0x169 #7 0xffffffff811db702 at VOP_LOCK1_APV+0x32 #8 0xffffffff82e89229 at null_lock+0x169 #9 0xffffffff811db702 at VOP_LOCK1_APV+0x32 #10 0xffffffff80cd9123 at _vn_lock+0x53 #11 0xffffffff80cbeb19 at vflush+0xe9 #12 0xffffffff82e87fd0 at nullfs_unmount+0x50 #13 0xffffffff80cb28b4 at dounmount+0x664 #14 0xffffffff80cb21fc at kern_unmount+0x35c #15 0xffffffff8110ba08 at amd64_syscall+0x168 #16 0xffffffff810db0ab at fast_syscall_common+0xf8 -- You are receiving this mail because: You are the assignee for the bug.home | help
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