ubuntu 20.04 kernel 5.8.. kolabuje se zapuntym cachefiles

Stav: komp s ubunutu 20.04 a jadro 5.8.36, pred tim 5.8.34, dnes po restaru a pokusu o prihlaseni komp zkolaboval...

stroj ma pripojene nektere slozky z jineho pres nfs ( mimo jine i /home),

fstab puvodni:
ip adresa:/home_server /home nfs4 defaults,hard,intr,fsc 0 0
s timto zkolabuje

pokud odmazu fsc, tedy takto:
ip adresa:/home_server /home nfs4 defaults,hard,intr 0 0
nezkolabuje

s jadrem 5.4... problem neni a mam dojem ze pred tim jsem tam mel nejake jadro 5.8.. chodilo to taky,
mimo to se mi povedelo stroj nastartovat i tak ze jsem ho pri bootu odpojil od site po te se prihlasil. pripojil sit, mount -a
a po te se rozebehl take normalne....

cast kernel.log:
an 8 11:50:25 desktop-amd kernel: [ 19.509971] CacheFiles: Loaded
Jan 8 11:50:25 desktop-amd kernel: [ 19.554956] FS-Cache: Cache "mycache" added (type cachefiles)
Jan 8 11:50:25 desktop-amd kernel: [ 19.554959] CacheFiles: File cache on sda2 registered
Jan 8 11:50:25 desktop-amd kernel: [ 19.720802] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
Jan 8 11:50:25 desktop-amd kernel: [ 19.721956] virbr0: port 1(virbr0-nic) entered blocking state
Jan 8 11:50:25 desktop-amd kernel: [ 19.721959] virbr0: port 1(virbr0-nic) entered disabled state
Jan 8 11:50:25 desktop-amd kernel: [ 19.722006] device virbr0-nic entered promiscuous mode
Jan 8 11:50:25 desktop-amd kernel: [ 19.765964] bpfilter: Loaded bpfilter_umh pid 2305
Jan 8 11:50:25 desktop-amd kernel: [ 20.160521] virbr0: port 1(virbr0-nic) entered blocking state
Jan 8 11:50:25 desktop-amd kernel: [ 20.160525] virbr0: port 1(virbr0-nic) entered listening state
Jan 8 11:50:25 desktop-amd kernel: [ 20.227881] virbr0: port 1(virbr0-nic) entered disabled state
Jan 8 11:50:25 desktop-amd kernel: [ 20.256017] CacheFiles:
Jan 8 11:50:25 desktop-amd kernel: [ 20.256021] CacheFiles: Assertion failed
Jan 8 11:50:25 desktop-amd kernel: [ 20.256067] ------------[ cut here ]------------
Jan 8 11:50:25 desktop-amd kernel: [ 20.256068] kernel BUG at fs/cachefiles/rdwr.c:717!
Jan 8 11:50:25 desktop-amd kernel: [ 20.256078] invalid opcode: 0000 [#1] SMP NOPTI
Jan 8 11:50:25 desktop-amd kernel: [ 20.256082] CPU: 1 PID: 2277 Comm: daemon-init Tainted: G OE 5.8.0-34-generic #37~20.04.2-Ubuntu
Jan 8 11:50:25 desktop-amd kernel: [ 20.256084] Hardware name: MSI MS-7913/A88XI AC V2 (MS-7913), BIOS V2.4 07/27/2016
Jan 8 11:50:25 desktop-amd kernel: [ 20.256093] RIP: 0010:cachefiles_read_or_alloc_pages.cold+0x32/0x4e [cachefiles]
Jan 8 11:50:25 desktop-amd kernel: [ 20.256096] Code: a6 8f c5 c0 48 c7 c7 48 48 4c c1 e8 9a 8f c5 c0 0f 0b 48 c7 c7 70 3b 4c c1 e8 8c 8f c5 c0 48 c7 c7 48 48 4c c1 e8 80 8f c5 c0 <0f> 0b 48 c7 c7 70 3>
Jan 8 11:50:25 desktop-amd kernel: [ 20.256098] RSP: 0018:ffffaf09825c3890 EFLAGS: 00010246
Jan 8 11:50:25 desktop-amd kernel: [ 20.256100] RAX: 000000000000001c RBX: ffff96a2d54fb448 RCX: 0000000000000027
Jan 8 11:50:25 desktop-amd kernel: [ 20.256101] RDX: 0000000000000000 RSI: 0000000000000086 RDI: ffff96a2efc98cd8
Jan 8 11:50:25 desktop-amd kernel: [ 20.256102] RBP: ffffaf09825c3980 R08: ffff96a2efc98cd0 R09: ffffffff83bcf8bc
Jan 8 11:50:25 desktop-amd kernel: [ 20.256104] R10: ffffffff83bb4988 R11: ffffaf09825c3710 R12: ffff96a28ce999c0
Jan 8 11:50:25 desktop-amd kernel: [ 20.256105] R13: 0000000000000000 R14: ffffaf09825c3b98 R15: ffffaf09825c3a24
Jan 8 11:50:25 desktop-amd kernel: [ 20.256107] FS: 00007f7668b7a700(0000) GS:ffff96a2efc80000(0000) knlGS:0000000000000000
Jan 8 11:50:25 desktop-amd kernel: [ 20.256109] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jan 8 11:50:25 desktop-amd kernel: [ 20.256110] CR2: 000055fb84fb8da4 CR3: 0000000415b30000 CR4: 00000000000406e0
Jan 8 11:50:25 desktop-amd kernel: [ 20.256111] Call Trace:

Dotaz: ubuntu 20.04 kernel 5.8.. kolabuje se zapuntym cachefiles