[Today's main-snapshot kernel panics as well.]

On Sep 7, 2023, at 16:32, Mark Millard <mark...@yahoo.com> wrote:

> On Sep 7, 2023, at 13:07, Alexander Motin <m...@freebsd.org> wrote:
> 
>> Thanks, Mark.
>> 
>> On 07.09.2023 15:40, Mark Millard wrote:
>>> On Sep 7, 2023, at 11:48, Glen Barber <g...@freebsd.org> wrote:
>>>> On Thu, Sep 07, 2023 at 11:17:22AM -0700, Mark Millard wrote:
>>>>> When I next have time, should I retry based on a more recent
>>>>> vintage of main that includes 969071be938c ?
>>>> 
>>>> Yes, please, if you can.
>>> As stands, I rebooted that machine into my normal
>>> enviroment, so the after-crash-with-dump-info
>>> context is preserved. I'll presume lack of a need
>>> to preserve that context unless I hear otherwise.
>>> (But I'll work on this until later today.)
>>> Even my normal environment predates the commit in
>>> question by a few commits. So I'll end up doing a
>>> more general round of updates overall.
>>> Someone can let me know if there is a preference
>>> for debug over non-debug for the next test run.
>> 
>> It is not unknown when some bugs disappear once debugging is enabled due to 
>> different execution timings, but generally debug may to detect the problem 
>> closer to its origin instead of looking on random consequences. I am only 
>> starting to look on this report (unless Pawel or somebody beat me on it), 
>> and don't have additional requests yet, but if you can repeat the same with 
>> debug kernel (in-base ZFS's ZFS_DEBUG setting follows kernel's INVARIANTS), 
>> it may give us some additional information.
> 
> So I did a zpool import, rewinding to the checkpoint.
> (This depends on the questionable zfs doing fully as
> desired for this. Notably the normal environment has
> vfs.zfs.bclone_enabled=0 , including when it was
> doing this activity.) My normal environment reported
> no problems.
> 
> Note: the earlier snapshot from my first setup was
> still in place since it was made just before the
> original checkpoint used above.
> 
> However, the rewind did remove the /var/crash/
> material that had been added.
> 
> I did the appropriate zfs mount.
> 
> I installed a debug kernel and world to the import. Again,
> no problems reported.
> 
> I did the appropriate zfs umount.
> 
> I did the appropriate zpool export.
> 
> I rebooted with the test media.
> 
> # sysctl vfs.zfs.bclone_enabled
> vfs.zfs.bclone_enabled: 1
> 
> # zpool trim -w zamd64
> 
> # zpool checkpoint zamd64
> 
> # uname -apKU
> FreeBSD amd64-ZFS 15.0-CURRENT FreeBSD 15.0-CURRENT amd64 1500000 #74 
> main-n265188-117c54a78ccd-dirty: Tue Sep  5 21:29:53 PDT 2023     
> root@amd64-ZFS:/usr/obj/BUILDs/main-amd64-dbg-clang/usr/main-src/amd64.amd64/sys/GENERIC-DBG
>  amd64 amd64 1500000 1500000
> 
> (So, before the 969071be938c vintage, same sources as for
> my last run but a debug build.)
> 
> # poudriere bulk -jmain-amd64-bulk_a -a
> . . .
> [00:03:23] Building 34214 packages using up to 32 builders
> [00:03:23] Hit CTRL+t at any time to see build progress and stats
> [00:03:23] [01] [00:00:00] Builder starting
> [00:04:19] [01] [00:00:56] Builder started
> [00:04:20] [01] [00:00:01] Building ports-mgmt/pkg | pkg-1.20.6
> [00:05:33] [01] [00:01:14] Finished ports-mgmt/pkg | pkg-1.20.6: Success
> [00:05:53] [01] [00:00:00] Building print/indexinfo | indexinfo-0.3.1
> [00:05:53] [02] [00:00:00] Builder starting
> . . .
> [00:05:54] [32] [00:00:00] Builder starting
> [00:06:11] [01] [00:00:18] Finished print/indexinfo | indexinfo-0.3.1: Success
> [00:06:12] [01] [00:00:00] Building devel/gettext-runtime | 
> gettext-runtime-0.22_1
> [00:08:24] [01] [00:02:12] Finished devel/gettext-runtime | 
> gettext-runtime-0.22_1: Success
> [00:08:31] [01] [00:00:00] Building devel/libtextstyle | libtextstyle-0.22
> [00:10:06] [05] [00:04:13] Builder started
> [00:10:06] [05] [00:00:00] Building devel/autoconf-switch | 
> autoconf-switch-20220527
> [00:10:06] [31] [00:04:12] Builder started
> [00:10:06] [31] [00:00:00] Building devel/libatomic_ops | libatomic_ops-7.8.0
> . . .
> 
> Crashed again, with 158 *.pkg files in .building/All/ after
> rebooting.
> 
> The crash is similar to the non-debug one. No extra output
> from the debug build.
> 
> For reference:
> 
> Unread portion of the kernel message buffer:
> panic: Solaris(panic): zfs: accessing past end of object 422/10b1c02 
> (size=2560 access=2560+2560)
> . . .

Same world with newer snapshot main kernel that should
be compatible with the world:

# uname -apKU
FreeBSD amd64-ZFS 15.0-CURRENT FreeBSD 15.0-CURRENT amd64 1500000 #0 
main-n265205-03a7c36ddbc0: Thu Sep  7 03:10:34 UTC 2023     
r...@releng3.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64 
amd64 1500000 1500000


Steps:

#NOTE: (re)boot to normal environment
#NOTE: login

cd ~/artifacts/

#NOTE: as needed . . .
fetch 
http://ftp3.freebsd.org/pub/FreeBSD/snapshots/amd64/15.0-CURRENT/kernel.txz
fetch 
http://ftp3.freebsd.org/pub/FreeBSD/snapshots/amd64/15.0-CURRENT/kernel-dbg.txz
fetch http://ftp3.freebsd.org/pub/FreeBSD/snapshots/amd64/15.0-CURRENT/src.txz

#NOTE: /zamd64-mnt is a pre-existing empty directory for such use:
zpool import --rewind-to-checkpoint -f -N -R /zamd64-mnt -t zamd64 zpamd64
zpool checkpoint zpamd64

#NOTE: My BE's for bectl use have mountpoint=none normally.
zfs set mountpoint=/ zpamd64/ROOT/main-amd64
zfs mount zpamd64/ROOT/main-amd64

mv /zamd64-mnt/boot/kernel /zamd64-mnt/boot/kernel.mm
tar -xpf kernel.txz -C /zamd64-mnt/

mv /zamd64-mnt/usr/lib/debug/boot/kernel 
/zamd64-mnt/usr/lib/debug/boot/kernel.mm
tar -xpf kernel-dbg.txz -C /zamd64-mnt/

zfs umount zpamd64/ROOT/main-amd64
zfs set mountpoint=none zpamd64/ROOT/main-amd64

zfs mount zpamd64/usr/src
#NOTE: /zamd64-mnt/usr/src/ being empty initially
#NOTE: My normal environment's source is in a worktree /usr/main-src/
tar -xpf src.txz -C /zamd64-mnt/
zfs umount zpamd64/usr/src

zpool export zpamd64

#NOTE: reboot to zamd64 #(my test environment)
#NOTE: login

uname -apKU

sysctl vfs.zfs.bclone_enabled

zpool trim -w zamd64
poudriere bulk -jmain-amd64-bulk_a -a

Paniced.

#NOTE: dump
#NOTE: reboot to zamd64 #(my test environment)
#NOTE: login

ls -Tlod 
/usr/local/poudriere/data/packages/main-amd64-bulk_a-default/.building/All/*.pkg
 | wc -l
     122

less /var/crash/core.txt.3
. . .
Unread portion of the kernel message buffer:
panic: Solaris(panic): zfs: accessing past end of object 422/10d670b (size=2560 
access=2560+2560)
cpuid = 18
time = 1694146387
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe033f721590
vpanic() at vpanic+0x132/frame 0xfffffe033f7216c0
panic() at panic+0x43/frame 0xfffffe033f721720
vcmn_err() at vcmn_err+0xeb/frame 0xfffffe033f721850
zfs_panic_recover() at zfs_panic_recover+0x59/frame 0xfffffe033f7218b0
dmu_buf_hold_array_by_dnode() at dmu_buf_hold_array_by_dnode+0xb8/frame 
0xfffffe033f721960
dmu_brt_clone() at dmu_brt_clone+0x61/frame 0xfffffe033f7219e0
zfs_clone_range() at zfs_clone_range+0xaa3/frame 0xfffffe033f721bb0
zfs_freebsd_copy_file_range() at zfs_freebsd_copy_file_range+0x18a/frame 
0xfffffe033f721c30
vn_copy_file_range() at vn_copy_file_range+0x163/frame 0xfffffe033f721ce0
kern_copy_file_range() at kern_copy_file_range+0x36c/frame 0xfffffe033f721db0
sys_copy_file_range() at sys_copy_file_range+0x78/frame 0xfffffe033f721e00
amd64_syscall() at amd64_syscall+0x138/frame 0xfffffe033f721f30
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe033f721f30
--- syscall (569, FreeBSD ELF64, copy_file_range), rip = 0x2c05a58a355a, rsp = 
0x2c05a4312138, rbp = 0x2c05a43125d0 ---
KDB: enter: panic

__curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57
57              __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" (offsetof(struct 
pcpu,
(kgdb) #0  __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57
#1  doadump (textdump=textdump@entry=0)
    at /usr/src/sys/kern/kern_shutdown.c:405
#2  0xffffffff804a401a in db_dump (dummy=<optimized out>,      
dummy2=<optimized out>, dummy3=<optimized out>, dummy4=<optimized out>)
    at /usr/src/sys/ddb/db_command.c:591
#3  0xffffffff804a3e1d in db_command (last_cmdp=<optimized out>,      
cmd_table=<optimized out>, dopager=true)
    at /usr/src/sys/ddb/db_command.c:504
#4  0xffffffff804a3add in db_command_loop ()
    at /usr/src/sys/ddb/db_command.c:551
#5  0xffffffff804a71b6 in db_trap (type=<optimized out>, code=<optimized out>)
    at /usr/src/sys/ddb/db_main.c:268
#6  0xffffffff80b9dfb3 in kdb_trap (type=type@entry=3, code=code@entry=0,      
tf=tf@entry=0xfffffe033f7214d0) at /usr/src/sys/kern/subr_kdb.c:790
#7  0xffffffff8104d579 in trap (frame=0xfffffe033f7214d0)
    at /usr/src/sys/amd64/amd64/trap.c:608
#8  <signal handler called>
#9  kdb_enter (why=<optimized out>, msg=<optimized out>)
    at /usr/src/sys/kern/subr_kdb.c:556
#10 0xffffffff80b4f683 in vpanic (fmt=0xffffffff8223d54e "%s%s",      
ap=ap@entry=0xfffffe033f721700) at /usr/src/sys/kern/kern_shutdown.c:958
#11 0xffffffff80b4f463 in panic (
    fmt=0xffffffff8196c800 <cnputs_mtx> "$\222\024\201\377\377\377\377")
    at /usr/src/sys/kern/kern_shutdown.c:894
#12 0xffffffff81f9964b in vcmn_err (ce=<optimized out>,      
fmt=0xffffffff82274462 "zfs: accessing past end of object %llx/%llx (size=%u 
access=%llu+%llu)", adx=0xfffffe033f721890)
    at /usr/src/sys/contrib/openzfs/module/os/freebsd/spl/spl_cmn_err.c:60
#13 0xffffffff820b6a59 in zfs_panic_recover (
    fmt=0x12 <error: Cannot access memory at address 0x12>)
    at /usr/src/sys/contrib/openzfs/module/zfs/spa_misc.c:1594
#14 0xffffffff820150d8 in dmu_buf_hold_array_by_dnode (dn=0xfffff802c3c41be8,   
   offset=offset@entry=2560, length=length@entry=2560, read=read@entry=0,      
tag=0xffffffff8222139b, numbufsp=numbufsp@entry=0xfffffe033f7219ac,      
dbpp=0xfffffe033f7219b0, flags=0)
    at /usr/src/sys/contrib/openzfs/module/zfs/dmu.c:543
#15 0xffffffff82018c31 in dmu_buf_hold_array (os=<optimized out>,      
object=<optimized out>, read=0, numbufsp=0xfffffe033f7219ac,      
dbpp=0xfffffe033f7219b0, offset=<optimized out>, length=<optimized out>,      
tag=<optimized out>) at /usr/src/sys/contrib/openzfs/module/zfs/dmu.c:654
#16 dmu_brt_clone (os=os@entry=0xfffff8019696b800, object=<optimized out>,      
offset=offset@entry=2560, length=length@entry=2560,      
tx=tx@entry=0xfffff81433e03d00, bps=bps@entry=0xfffffe0442ce5000, nbps=1,      
replay=0) at /usr/src/sys/contrib/openzfs/module/zfs/dmu.c:2301
#17 0xffffffff82183333 in zfs_clone_range (inzp=0xfffff80e37f64000,      
inoffp=0xfffff8019ab32b38, outzp=0xfffff80d931a5910,      
outoffp=0xfffff80662d0a548, lenp=lenp@entry=0xfffffe033f721bf0,      
cr=0xfffff8051d1c4800)
    at /usr/src/sys/contrib/openzfs/module/zfs/zfs_vnops.c:1302
#18 0xffffffff81fbc76a in zfs_freebsd_copy_file_range (ap=0xfffffe033f721c48)
    at /usr/src/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c:6294
#19 0xffffffff80c612a3 in VOP_COPY_FILE_RANGE (invp=0xfffff80eb09c08c0,      
inoffp=0xfffff8019ab32b38, outvp=0xfffff80e7f998000,      
outoffp=0xfffff80662d0a548, lenp=0xfffffe033f721d40,      
incred=0xfffff8051d1c4800, flags=<optimized out>,      outcred=<optimized out>, 
fsizetd=<optimized out>) at ./vnode_if.h:2385
#20 vn_copy_file_range (invp=invp@entry=0xfffff80eb09c08c0,      
inoffp=inoffp@entry=0xfffff8019ab32b38,      
outvp=outvp@entry=0xfffff80e7f998000, outoffp=0xfffff80662d0a548,      
lenp=lenp@entry=0xfffffe033f721d40, flags=flags@entry=0,      
incred=0xfffff8051d1c4800, outcred=0xfffff8051d1c4800,      
fsize_td=0xfffffe033fdf1c80) at /usr/src/sys/kern/vfs_vnops.c:3087
#21 0xffffffff80c5be9c in kern_copy_file_range (
    td=td@entry=0xfffffe033fdf1c80, infd=<optimized out>,      
inoffp=0xfffff8019ab32b38, inoffp@entry=0x0, outfd=<optimized out>,      
outoffp=0xffffffff8120f47f, outoffp@entry=0x0, len=9223372036854775807,      
flags=0) at /usr/src/sys/kern/vfs_syscalls.c:4971
#22 0xffffffff80c5bfa8 in sys_copy_file_range (td=0xfffffe033fdf1c80,      
uap=0xfffffe033fdf2080) at /usr/src/sys/kern/vfs_syscalls.c:5009
#23 0xffffffff8104e3d8 in syscallenter (td=<optimized out>)
    at /usr/src/sys/amd64/amd64/../../kern/subr_syscall.c:187
#24 amd64_syscall (td=0xfffffe033fdf1c80, traced=0)
    at /usr/src/sys/amd64/amd64/trap.c:1197
#25 <signal handler called>
#26 0x00002c05a58a355a in ?? ()
Backtrace stopped: Cannot access memory at address 0x2c05a4312138
(kgdb) 
. . .


So the problem is not special to my personal kernel builds.


>>> Looking at "git: 969071be938c - main", the relevant
>>> part seems to be just (white space possibly not
>>> preserved accurately):
>>> diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
>>> index 9fb5aee6a023..4e4161ef1a7f 100644
>>> --- a/sys/kern/vfs_vnops.c
>>> +++ b/sys/kern/vfs_vnops.c
>>> @@ -3076,12 +3076,14 @@ vn_copy_file_range(struct vnode *invp, off_t 
>>> *inoffp, struct vnode *outvp,
>>>  goto out;
>>>    /*
>>> - * If the two vnode are for the same file system, call
>>> + * If the two vnodes are for the same file system type, call
>>>  * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
>>> - * which can handle copies across multiple file systems.
>>> + * which can handle copies across multiple file system types.
>>>  */
>>>  *lenp = len;
>>> - if (invp->v_mount == outvp->v_mount)
>>> + if (invp->v_mount == outvp->v_mount ||
>>> +    strcmp(invp->v_mount->mnt_vfc->vfc_name,
>>> +    outvp->v_mount->mnt_vfc->vfc_name) == 0)
>>>  error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
>>>     lenp, flags, incred, outcred, fsize_td);
>>>  else
>>> That looks to call VOP_COPY_FILE_RANGE in more contexts and
>>> vn_generic_copy_file_range in fewer.
>>> The backtrace I reported involves: VOP_COPY_FILE_RANGE
>>> So it appears this change is unlikely to invalidate my
>>> test result,  although failure might happen sooner if
>>> more VOP_COPY_FILE_RANGE calls happen with the newer code.
>> 
>> Your logic is likely right, but if you have block cloning requests both 
>> within and between datasets, this patch may change the pattern.  Though it 
>> is obviously not a fix for the issue.  I responded to the commit email only 
>> because it makes no difference while vfs.zfs.bclone_enabled is 0.
>> 
>>> That in turns means that someone may come up with some
>>> other change for me to test by the time I get around to
>>> setting up another test. Let me know if so.
>> . . .


===
Mark Millard
marklmi at yahoo.com


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