[25] lock order reversal: [25] 1st 0xfffffe03dea4e1c0 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:3130 [25] 2nd 0xfffff8000d61c7b0 snaplk (snaplk) @ /usr/src/sys/ufs/ffs/ffs_snapshot.c:2298 [25] KDB: stack backtrace: [25] db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe04656f8310 [25] kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe04656f83c0 [25] witness_checkorder() at witness_checkorder+0xe12/frame 0xfffffe04656f8450 [25] __lockmgr_args() at __lockmgr_args+0x9ea/frame 0xfffffe04656f8590 [25] ffs_copyonwrite() at ffs_copyonwrite+0x179/frame 0xfffffe04656f8640 [25] ffs_geom_strategy() at ffs_geom_strategy+0xe6/frame 0xfffffe04656f8670 [25] bufwrite() at bufwrite+0x19a/frame 0xfffffe04656f86c0 [25] ffs_update() at ffs_update+0x2b8/frame 0xfffffe04656f8740 [25] ffs_syncvnode() at ffs_syncvnode+0x485/frame 0xfffffe04656f87c0 [25] ffs_fsync() at ffs_fsync+0x20/frame 0xfffffe04656f87f0 [25] VOP_FSYNC_APV() at VOP_FSYNC_APV+0xd1/frame 0xfffffe04656f8820 [25] sys_fsync() at sys_fsync+0x175/frame 0xfffffe04656f88a0 [25] amd64_syscall() at amd64_syscall+0x2a8/frame 0xfffffe04656f89b0 [25] Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe04656f89b0 [25] --- syscall (95, FreeBSD ELF64, sys_fsync), rip = 0x243328448ca, rsp = 0x67f303cb9a58, rbp = 0x67f303cbab00 ---