Re: r268621: panic: shadowed tmpfs v_object [with dump]

From: Bryan Drewery <bdrewery_at_FreeBSD.org>
Date: Wed, 23 Jul 2014 09:12:59 -0700
On 7/23/14, 7:11 AM, Konstantin Belousov wrote:
> On Tue, Jul 22, 2014 at 02:53:56PM -0700, Bryan Drewery wrote:
>> On 7/22/14, 2:26 PM, Bryan Drewery wrote:
>>> On 7/22/14, 2:07 PM, Bryan Drewery wrote:
>>>> Meant to send to current_at_, moving there.
>>>>
>>>> On 7/22/14, 2:07 PM, Bryan Drewery wrote:
>>>>> On r268621:
>>>>>
>>>>>> panic: shadowed tmpfs v_object 0xfffff807a7f96600
>>>>>> cpuid = 0
>>>>>> KDB: stack backtrace:
>>>>>> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
>>>>>> 0xfffffe1247d67390
>>>>>> kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe1247d67440
>>>>>> vpanic() at vpanic+0x126/frame 0xfffffe1247d67480
>>>>>> kassert_panic() at kassert_panic+0x139/frame 0xfffffe1247d674f0
>>>>>> vm_object_deallocate() at vm_object_deallocate+0x236/frame
>>>>>> 0xfffffe1247d67550
>>>>>> tmpfs_free_node() at tmpfs_free_node+0x138/frame 0xfffffe1247d67580
>>>>>> tmpfs_reclaim() at tmpfs_reclaim+0x17d/frame 0xfffffe1247d675c0
>>>>>> VOP_RECLAIM_APV() at VOP_RECLAIM_APV+0xf7/frame 0xfffffe1247d675f0
>>>>>> vgonel() at vgonel+0x1a1/frame 0xfffffe1247d67660
>>>>>> vrecycle() at vrecycle+0x3e/frame 0xfffffe1247d67690
>>>>>> tmpfs_inactive() at tmpfs_inactive+0x4c/frame 0xfffffe1247d676b0
>>>>>> VOP_INACTIVE_APV() at VOP_INACTIVE_APV+0xf7/frame 0xfffffe1247d676e0
>>>>>> vinactive() at vinactive+0xc6/frame 0xfffffe1247d67730
>>>>>> vputx() at vputx+0x27a/frame 0xfffffe1247d67790
>>>>>> tmpfs_rename() at tmpfs_rename+0xf5/frame 0xfffffe1247d67860
>>>>>> VOP_RENAME_APV() at VOP_RENAME_APV+0xfc/frame 0xfffffe1247d67890
>>>>>> kern_renameat() at kern_renameat+0x3ef/frame 0xfffffe1247d67ae0
>>>>>> amd64_syscall() at amd64_syscall+0x25a/frame 0xfffffe1247d67bf0
>>>>>> Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe1247d67bf0
>>>>>> --- syscall (128, FreeBSD ELF64, sys_rename), rip = 0x80088b74a, rsp =
>>>>>> 0x7fffffffe238, rbp = 0x7fffffffe710 ---
>>>>>> Uptime: 6d4h0m3s
>>>>>>
>>>>>> Dump failed. Partition too small.
>>>>>
>>>>> Unfortunately I have no dump to debug.
>>>>>
>>>>
>>> Running poudriere again after boot hit the issue right away:
>>>
>>>
>>>> (kgdb) bt
>>>> #0  doadump (textdump=1) at pcpu.h:219
>>>> #1  0xffffffff809122a7 in kern_reboot (howto=260) at
>>>> /usr/src/sys/kern/kern_shutdown.c:445
>>>> #2  0xffffffff809127e5 in vpanic (fmt=<value optimized out>, ap=<value
>>>> optimized out>) at /usr/src/sys/kern/kern_shutdown.c:744
>>>> #3  0xffffffff80912679 in kassert_panic (fmt=<value optimized out>) at
>>>> /usr/src/sys/kern/kern_shutdown.c:632
>>>> #4  0xffffffff80ba7996 in vm_object_deallocate (object=<value
>>>> optimized out>) at /usr/src/sys/vm/vm_object.c:562
>>>> #5  0xffffffff820a75a8 in tmpfs_free_node (tmp=0xfffff800b5155980,
>>>> node=0xfffff802716ba740) at
>>>> /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_subr.c:335
>>>> #6  0xffffffff820a363d in tmpfs_reclaim (v=<value optimized out>) at
>>>> /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vnops.c:1276
>>>> #7  0xffffffff80e48717 in VOP_RECLAIM_APV (vop=<value optimized out>,
>>>> a=<value optimized out>) at vnode_if.c:2017
>>>> #8  0xffffffff809c1381 in vgonel (vp=0xfffff802716b61d8) at
>>>> vnode_if.h:830
>>>> #9  0xffffffff809c18be in vrecycle (vp=0xfffff802716b61d8) at
>>>> /usr/src/sys/kern/vfs_subr.c:2655
>>>> #10 0xffffffff820a61cc in tmpfs_inactive (v=<value optimized out>) at
>>>> /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vnops.c:1242
>>>> #11 0xffffffff80e485b7 in VOP_INACTIVE_APV (vop=<value optimized out>,
>>>> a=<value optimized out>) at vnode_if.c:1951
>>>> #12 0xffffffff809bfd36 in vinactive (vp=0xfffff802716b61d8,
>>>> td=0xfffff80187e29920) at vnode_if.h:807
>>>> #13 0xffffffff809c012a in vputx (vp=0xfffff802716b61d8, func=2) at
>>>> /usr/src/sys/kern/vfs_subr.c:2267
>>>> #14 0xffffffff820a47c5 in tmpfs_rename (v=<value optimized out>) at
>>>> /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vnops.c:1023
>>>> #15 0xffffffff80e47d3c in VOP_RENAME_APV (vop=<value optimized out>,
>>>> a=<value optimized out>) at vnode_if.c:1544
>>>> #16 0xffffffff809cc77f in kern_renameat (td=<value optimized out>,
>>>> oldfd=<value optimized out>, old=<value optimized out>, newfd=<value
>>>> optimized out>, new=<value optimized out>,
>>>>      pathseg=<value optimized out>) at vnode_if.h:636
>>>> #17 0xffffffff80d280fa in amd64_syscall (td=0xfffff80187e29920,
>>>> traced=0) at subr_syscall.c:133
>>>> #18 0xffffffff80d0a64b in Xfast_syscall () at
>>>> /usr/src/sys/amd64/amd64/exception.S:407
>>>> (kgdb) p *(vm_object_t)0xfffff8027169f500
>>>> $1 = {lock = {lock_object = {lo_name = 0xffffffff80fe89f6 "vm object",
>>>> lo_flags = 90374144, lo_data = 0, lo_witness = 0xfffffe00006e7680},
>>>> rw_lock = 18446735284191271200}, object_list = {
>>>>      tqe_next = 0xfffff8027169f400, tqe_prev = 0xfffff8027169f620},
>>>> shadow_head = {lh_first = 0xfffff801b8489e00}, shadow_list = {le_next
>>>> = 0x0, le_prev = 0x0}, memq = {tqh_first = 0xfffff811d966bc08,
>>>>      tqh_last = 0xfffff811d966bc18}, rtree = {rt_root =
>>>> 18446735354278362121, rt_flags = 0 '\0'}, size = 1, generation = 1,
>>>> ref_count = 1, shadow_count = 1, memattr = 6 '\006', type = 1 '\001',
>>>>    flags = 528, pg_color = 0, paging_in_progress = 0,
>>>> resident_page_count = 1, backing_object = 0x0, backing_object_offset =
>>>> 0, pager_object_list = {tqe_next = 0x0, tqe_prev = 0x0}, rvq = {
>>>>      lh_first = 0x0}, cache = {rt_root = 0, rt_flags = 0 '\0'}, handle
>>>> = 0x0, un_pager = {vnp = {vnp_size = 0, writemappings = 0}, devp =
>>>> {devp_pglist = {tqh_first = 0x0, tqh_last = 0x0}, ops = 0x0,
>>>>        dev = 0x0}, sgp = {sgp_pglist = {tqh_first = 0x0, tqh_last =
>>>> 0x0}}, swp = {swp_tmpfs = 0x0, swp_bcount = 0}}, cred = 0x0, charge = 0}
>>>> (kgdb) frame 8
>>>> #8  0xffffffff809c1381 in vgonel (vp=0xfffff802716b61d8) at
>>>> vnode_if.h:830
>>>> 830             return (VOP_RECLAIM_APV(vp->v_op, &a));
>>>> (kgdb) p *vp
>>>> $2 = {v_tag = 0xffffffff820abf96 "tmpfs", v_op = 0xffffffff820ac938,
>>>> v_data = 0x0, v_mount = 0xfffff8004733a000, v_nmntvnodes = {tqe_next =
>>>> 0xfffff802716b6000, tqe_prev = 0xfffff802716b63d0}, v_un = {
>>>>      vu_mount = 0x0, vu_socket = 0x0, vu_cdev = 0x0, vu_fifoinfo =
>>>> 0x0}, v_hashlist = {le_next = 0x0, le_prev = 0x0}, v_cache_src =
>>>> {lh_first = 0x0}, v_cache_dst = {tqh_first = 0x0,
>>>>      tqh_last = 0xfffff802716b6228}, v_cache_dd = 0x0, v_lock =
>>>> {lock_object = {lo_name = 0xffffffff820abf96 "tmpfs", lo_flags =
>>>> 116588544, lo_data = 0, lo_witness = 0xfffffe0000711980},
>>>>      lk_lock = 18446735284191271200, lk_exslpfail = 0, lk_timo = 51,
>>>> lk_pri = 96}, v_interlock = {lock_object = {lo_name =
>>>> 0xffffffff80fafc26 "vnode interlock", lo_flags = 16973824, lo_data = 0,
>>>>        lo_witness = 0xfffffe00006e7500}, mtx_lock = 4}, v_vnlock =
>>>> 0xfffff802716b6240, v_actfreelist = {tqe_next = 0xfffff80271898588,
>>>> tqe_prev = 0xfffff8004733a078}, v_bufobj = {bo_lock = {
>>>>        lock_object = {lo_name = 0xffffffff80fb8084 "bufobj interlock",
>>>> lo_flags = 86179840, lo_data = 0, lo_witness = 0xfffffe00006ef380},
>>>> rw_lock = 1}, bo_ops = 0xffffffff814942a0, bo_object = 0x0,
>>>>      bo_synclist = {le_next = 0x0, le_prev = 0x0}, bo_private =
>>>> 0xfffff802716b61d8, __bo_vnode = 0xfffff802716b61d8, bo_clean = {bv_hd
>>>> = {tqh_first = 0x0, tqh_last = 0xfffff802716b62f8}, bv_root = {
>>>>          pt_root = 0}, bv_cnt = 0}, bo_dirty = {bv_hd = {tqh_first =
>>>> 0x0, tqh_last = 0xfffff802716b6318}, bv_root = {pt_root = 0}, bv_cnt =
>>>> 0}, bo_numoutput = 0, bo_flag = 0, bo_bsize = 4096},
>>>>    v_pollinfo = 0x0, v_label = 0x0, v_lockf = 0x0, v_rl = {rl_waiters =
>>>> {tqh_first = 0x0, tqh_last = 0xfffff802716b6360}, rl_currdep = 0x0},
>>>> v_cstart = 0, v_lasta = 0, v_lastw = 0, v_clen = 0,
>>>>    v_holdcnt = 2, v_usecount = 0, v_iflag = 2688, v_vflag = 0,
>>>> v_writecount = 0, v_hash = 40987489, v_type = VREG}
>>>> (kgdb) info locals
>>>> mp = (struct mount *) 0xfffff8004733a000
>>>> fromnd = {ni_dirp = 0x801006080 <Address 0x801006080 out of bounds>,
>>>> ni_segflg = UIO_USERSPACE, ni_rightsneeded = {cr_rights =
>>>> {144115188142965760, 288230376151711744}},
>>>>    ni_startdir = 0xfffff802716b63b0, ni_rootdir = 0xfffff8026b01a760,
>>>> ni_topdir = 0xfffff8026b01a760, ni_dirfd = -100, ni_strictrelative =
>>>> 0, ni_filecaps = {fc_rights = {cr_rights = {0, 0}},
>>>>      fc_ioctls = 0x0, fc_nioctls = -1, fc_fcntls = 0}, ni_vp =
>>>> 0xfffff80271898588, ni_dvp = 0xfffff802716b63b0, ni_pathlen = 1,
>>>> ni_next = 0xfffff80061ea501f "", ni_loopcnt = 0, ni_cnd = {cn_nameiop
>>>> = 2,
>>>>      cn_flags = 67148812, cn_thread = 0xfffff80187e29920, cn_cred =
>>>> 0xfffff80038911800, cn_lkflags = 524288, cn_pnbuf = 0xfffff80061ea5000
>>>> "/var/run/ld-elf.so.hints.HTjP6A",
>>>>      cn_nameptr = 0xfffff80061ea5009 "ld-elf.so.hints.HTjP6A",
>>>> cn_namelen = 22, cn_consume = 0}}
>>>> tond = {ni_dirp = 0x403e66 <Address 0x403e66 out of bounds>, ni_segflg
>>>> = UIO_USERSPACE, ni_rightsneeded = {cr_rights = {144115188080051200,
>>>> 288230376151711744}}, ni_startdir = 0xfffff802716b63b0,
>>>>    ni_rootdir = 0xfffff8026b01a760, ni_topdir = 0xfffff8026b01a760,
>>>> ni_dirfd = -100, ni_strictrelative = 0, ni_filecaps = {fc_rights =
>>>> {cr_rights = {0, 0}}, fc_ioctls = 0x0, fc_nioctls = -1,
>>>>      fc_fcntls = 0}, ni_vp = 0xfffff802716b61d8, ni_dvp =
>>>> 0xfffff802716b63b0, ni_pathlen = 1, ni_next = 0xfffff80038d69418 "",
>>>> ni_loopcnt = 0, ni_cnd = {cn_nameiop = 3, cn_flags = 134257708,
>>>>      cn_thread = 0xfffff80187e29920, cn_cred = 0xfffff80038911800,
>>>> cn_lkflags = 524288, cn_pnbuf = 0xfffff80038d69400
>>>> "/var/run/ld-elf.so.hints", cn_nameptr = 0xfffff80038d69409
>>>> "ld-elf.so.hints",
>>>>      cn_namelen = 15, cn_consume = 0}}
>>>> rights = {cr_rights = {144115188080051200, 288230376151711744}}
>>>> mp = (struct mount *) 0xfffff8004733a000
>>>> error = <value optimized out>
>>>> fvp = <value optimized out>
>>>> tvp = <value optimized out>
>>>> tdvp = <value optimized out>
>>>> (kgdb) p *mp
>>>> $9 = {mnt_mtx = {lock_object = {lo_name = 0xffffffff80f8fcec "struct
>>>> mount mtx", lo_flags = 16973824, lo_data = 0, lo_witness =
>>>> 0xfffffe00006e7a00}, mtx_lock = 4}, mnt_gen = 1, mnt_list = {
>>>>      tqe_next = 0xfffff80038fa9cc0, tqe_prev = 0xfffff80187b74ce8},
>>>> mnt_op = 0xffffffff820ace60, mnt_vfc = 0xffffffff820acf80,
>>>> mnt_vnodecovered = 0xfffff801b853e760, mnt_syncer = 0xfffff8026b01a588,
>>>>    mnt_ref = 13206, mnt_nvnodelist = {tqh_first = 0xfffff8026b01a760,
>>>> tqh_last = 0xfffff802718985a8}, mnt_nvnodelistsize = 13205,
>>>> mnt_activevnodelist = {tqh_first = 0xfffff802716b61d8,
>>>>      tqh_last = 0xfffff8026b01a648}, mnt_activevnodelistsize = 730,
>>>> mnt_writeopcount = 1, mnt_kern_flag = 0, mnt_flag = 4096, mnt_opt =
>>>> 0xfffff8000e59cc30, mnt_optnew = 0xfffff8001b9ea050,
>>>>    mnt_maxsymlinklen = 0, mnt_stat = {f_version = 537068824, f_type =
>>>> 135, f_flags = 4096, f_bsize = 4096, f_iosize = 4096, f_blocks =
>>>> 1835008, f_bfree = 1738991, f_bavail = 1738991, f_files = 25690112,
>>>>      f_ffree = 25676911, f_syncwrites = 0, f_asyncwrites = 0,
>>>> f_syncreads = 0, f_asyncreads = 0, f_spare = {0, 0, 0, 0, 0, 0, 0, 0,
>>>> 0, 0}, f_namemax = 255, f_owner = 0, f_fsid = {val = {-2029977843,
>>>>          135}}, f_charspare = '\0' <repeats 79 times>, f_fstypename =
>>>> "tmpfs\000\000\000\000\000\000\000\000\000\000", f_mntfromname =
>>>> "tmpfs", '\0' <repeats 82 times>,
>>>>      f_mntonname = "/poudriere/data/.m/exp-10amd64-commit-test/01",
>>>> '\0' <repeats 42 times>}, mnt_cred = 0xfffff80047478700, mnt_data =
>>>> 0xfffff800b5155980, mnt_time = 0, mnt_iosize_max = 65536,
>>>>    mnt_export = 0x0, mnt_label = 0x0, mnt_hashseed = 1147308587,
>>>> mnt_lockref = 0, mnt_secondary_writes = 0, mnt_secondary_accwrites =
>>>> 0, mnt_susp_owner = 0x0, mnt_gjprovider = 0x0, mnt_explock = {
>>>>      lock_object = {lo_name = 0xffffffff80f8fd0f "explock", lo_flags =
>>>> 108199936, lo_data = 0, lo_witness = 0xfffffe000070ef80}, lk_lock = 1,
>>>> lk_exslpfail = 0, lk_timo = 0, lk_pri = 96},
>>>>    mnt_upper_link = {tqe_next = 0x0, tqe_prev = 0x0}, mnt_uppers =
>>>> {tqh_first = 0x0, tqh_last = 0xfffff8004733a320}}
>>>
>>
>> Shadowed object:
>>
>>> (kgdb) p *$1->shadow_head->lh_first
>>> $3 = {lock = {lock_object = {lo_name = 0xffffffff80fe89f6 "vm object", lo_flags = 90374144, lo_data = 0, lo_witness = 0xfffffe00006e7680}, rw_lock = 1}, object_list = {tqe_next = 0xfffff801b8b3ae00,
>>>      tqe_prev = 0xfffff802717bb120}, shadow_head = {lh_first = 0x0}, shadow_list = {le_next = 0x0, le_prev = 0xfffff8027169f530}, memq = {tqh_first = 0xfffff811da2c75f8, tqh_last = 0xfffff811da2c7608},
>>>    rtree = {rt_root = 18446735354291320313, rt_flags = 0 '\0'}, size = 1, generation = 1, ref_count = 1, shadow_count = 0, memattr = 6 '\006', type = 0 '\0', flags = 12288, pg_color = 1598,
>>>    paging_in_progress = 0, resident_page_count = 1, backing_object = 0xfffff8027169f500, backing_object_offset = 0, pager_object_list = {tqe_next = 0x0, tqe_prev = 0x0}, rvq = {lh_first = 0x0}, cache = {
>>>      rt_root = 0, rt_flags = 0 '\0'}, handle = 0x0, un_pager = {vnp = {vnp_size = 0, writemappings = 0}, devp = {devp_pglist = {tqh_first = 0x0, tqh_last = 0x0}, ops = 0x0, dev = 0x0}, sgp = {
>>>        sgp_pglist = {tqh_first = 0x0, tqh_last = 0x0}}, swp = {swp_tmpfs = 0x0, swp_bcount = 0}}, cred = 0xfffff80038911800, charge = 4096}
>>
>
> Try this
>
> diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
> index 1b97bdf..bb01f00 100644
> --- a/sys/vm/vm_object.c
> +++ b/sys/vm/vm_object.c
> _at__at_ -559,8 +559,6 _at__at_ vm_object_deallocate(vm_object_t object)
>   			    (object->handle == NULL) &&
>   			    (object->type == OBJT_DEFAULT ||
>   			     object->type == OBJT_SWAP)) {
> -				KASSERT((object->flags & OBJ_TMPFS_NODE) == 0,
> -				    ("shadowed tmpfs v_object %p", object));
>   				vm_object_t robject;
>
>   				robject = LIST_FIRST(&object->shadow_head);
> _at__at_ -568,6 +566,8 _at__at_ vm_object_deallocate(vm_object_t object)
>   				    ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
>   					 object->ref_count,
>   					 object->shadow_count));
> +				KASSERT((robject->flags & OBJ_TMPFS_NODE) == 0,
> +				    ("shadowed tmpfs v_object %p", object));
>   				if (!VM_OBJECT_TRYWLOCK(robject)) {
>   					/*
>   					 * Avoid a potential deadlock.
> _at__at_ -637,6 +637,8 _at__at_ retry:
>   doterm:
>   		temp = object->backing_object;
>   		if (temp != NULL) {
> +			KASSERT((object->flags & OBJ_TMPFS_NODE) == 0,
> +			    ("shadowed tmpfs v_object 2 %p", object));
>   			VM_OBJECT_WLOCK(temp);
>   			LIST_REMOVE(object, shadow_list);
>   			temp->shadow_count--;
>

Yup this avoids the panic.

Thanks!

-- 
Regards,
Bryan Drewery
Received on Wed Jul 23 2014 - 14:13:03 UTC

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