-CURRENT panics in NFS

Sat Feb 27 15:53:19 UTC 2021

I reproduced the problem and the attached trivial patch
seems to fix it. Please test the patch if you can.

Mateusz, I assume the directory shouldn't try and add
a cache entry for itself?
I don't test NFSv3 much and I don't test "rdirplus"
much, so it slipped through the cracks.

Thanks for reporting it, rick

________________________________________
From: owner-freebsd-current at freebsd.org <owner-freebsd-current at freebsd.org> on behalf of Juraj Lutter <otis at FreeBSD.org>
Sent: Saturday, February 27, 2021 9:31 AM
To: freebsd-current
Subject: Re: -CURRENT panics in NFS

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And a kgdb backtrace:

(kgdb) bt
#0  __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:55
#1  doadump (textdump=textdump at entry=0) at /usr/src/sys/kern/kern_shutdown.c:399
#2  0xffffffff804c7b2a in db_dump (dummy=<optimized out>, dummy2=<unavailable>, dummy3=<unavailable>, dummy4=<unavailable>) at /usr/src/sys/ddb/db_command.c:575
#3  0xffffffff804c78ee in db_command (last_cmdp=<optimized out>, cmd_table=<optimized out>, dopager=dopager at entry=1) at /usr/src/sys/ddb/db_command.c:482
#4  0xffffffff804c762d in db_command_loop () at /usr/src/sys/ddb/db_command.c:535
#5  0xffffffff804cac36 in db_trap (type=<optimized out>, code=<optimized out>) at /usr/src/sys/ddb/db_main.c:270
#6  0xffffffff80c59d04 in kdb_trap (type=type at entry=3, code=code at entry=0, tf=<optimized out>, tf at entry=0xfffffe00d01c3d40) at /usr/src/sys/kern/subr_kdb.c:727
#7  0xffffffff810bc1ee in trap (frame=0xfffffe00d01c3d40) at /usr/src/sys/amd64/amd64/trap.c:576
#8  <signal handler called>
#9  kdb_enter (why=0xffffffff812accc9 "panic", msg=<optimized out>) at /usr/src/sys/kern/subr_kdb.c:506
#10 0xffffffff80c0d5d2 in vpanic (fmt=<optimized out>, ap=<optimized out>, ap at entry=0xfffffe00d01c3ea0) at /usr/src/sys/kern/kern_shutdown.c:907
#11 0xffffffff80c0d363 in panic (fmt=0xffffffff81e9a178 <cnputs_mtx> "\177\256&\201\377\377\377\377") at /usr/src/sys/kern/kern_shutdown.c:843
#12 0xffffffff80cd6d74 in cache_enter_time (dvp=0xfffff80079321e00, vp=0xfffff80079321e00, cnp=cnp at entry=0xfffffe00d01c4030, tsp=tsp at entry=0xfffffe00d01c40e0, dtsp=<optimized out>)
    at /usr/src/sys/kern/vfs_cache.c:2274
#13 0xffffffff80ae2bd6 in nfsrpc_readdirplus (vp=<optimized out>, vp at entry=0xfffff80079321e00, uiop=<optimized out>, uiop at entry=0xfffffe00d01c4540,
    cookiep=cookiep at entry=0xfffffe00d01c44e0, cred=cred at entry=0xfffff80079307e00, p=<optimized out>, p at entry=0xfffffe00de06be00, nap=nap at entry=0xfffffe00d01c4400,
    attrflagp=0xfffffe00d01c44f0, eofp=0xfffffe00d01c44f4, stuff=0x0) at /usr/src/sys/fs/nfsclient/nfs_clrpcops.c:3766
#14 0xffffffff80aed4ec in ncl_readdirplusrpc (vp=vp at entry=0xfffff80079321e00, uiop=uiop at entry=0xfffffe00d01c4540, cred=0xfffff80079307e00, td=td at entry=0xfffffe00de06be00)
    at /usr/src/sys/fs/nfsclient/nfs_clvnops.c:2490
#15 0xffffffff80afdc93 in ncl_doio (vp=vp at entry=0xfffff80079321e00, bp=bp at entry=0xfffffe000ee1c610, cr=0xfffffe00d01c3d00, cr at entry=0xfffff80079307e00, td=td at entry=0xfffffe00de06be00,
    called_from_strategy=called_from_strategy at entry=0) at /usr/src/sys/fs/nfsclient/nfs_clbio.c:1686
#16 0xffffffff80afce3c in ncl_bioread (vp=<optimized out>, vp at entry=0xfffff80079321e00, uio=<optimized out>, ioflag=ioflag at entry=0, cred=<optimized out>)
    at /usr/src/sys/fs/nfsclient/nfs_clbio.c:604
#17 0xffffffff80af1baf in nfs_readdir (ap=ap at entry=0xfffffe00d01c4918) at /usr/src/sys/fs/nfsclient/nfs_clvnops.c:2383
#18 0xffffffff80ce490f in vop_sigdefer (vop=<optimized out>, a=0xfffffe00d01c4918) at /usr/src/sys/kern/vfs_default.c:1471
#19 0xffffffff81181f38 in VOP_READDIR_APV (vop=0xffffffff81af00d8 <newnfs_vnodeops>, a=a at entry=0xfffffe00d01c4918) at vnode_if.c:1939
#20 0xffffffff80d0b23b in VOP_READDIR (vp=0xfffff80079321e00, uio=0xfffffe00d01c48d0, cred=<optimized out>, eofflag=0xfffffe00d01c48cc, ncookies=0x0, cookies=0x0) at ./vnode_if.h:985
#21 kern_getdirentries (td=<optimized out>, fd=<optimized out>, buf=0x801851000 <error: Cannot access memory at address 0x801851000>, count=4096, basep=basep at entry=0xfffffe00d01c49b0,
    residp=residp at entry=0x0, bufseg=UIO_USERSPACE) at /usr/src/sys/kern/vfs_syscalls.c:4142
#22 0xffffffff80d0b449 in sys_getdirentries (td=0xffffffff81e9a178 <cnputs_mtx>, uap=0xfffffe00de06c1e8) at /usr/src/sys/kern/vfs_syscalls.c:4089
#23 0xffffffff810bd00e in syscallenter (td=<optimized out>) at /usr/src/sys/amd64/amd64/../../kern/subr_syscall.c:189
#24 amd64_syscall (td=0xfffffe00de06be00, traced=0) at /usr/src/sys/amd64/amd64/trap.c:1156
#25 <signal handler called>
#26 0x00000008012a83fa in ?? ()
Backtrace stopped: Cannot access memory at address 0x7fffffffd928

—
Juraj Lutter
XMPP: juraj (at) lutter.sk
GSM: +421907986576

> On 27 Feb 2021, at 15:18, Juraj Lutter <otis at FreeBSD.org> wrote:
>
> Reliably reproducible:
>

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