ksmbd hangs with macOS clients - "unsupported INVOKE method 45, alloc_hint : 52"?

[victorhooi]

I'm running into a weird issue with ksmbd, where macOS clients seem to hang the server, requiring ksmbd to restart.

Specifically, when I try to open up multiple folders on the ksmbd share, after a while, the macOS client seems to disconnect. Anecdotally, I think this seems to be more pronounced with large folders with lots of files, or nested folders, although it's hard to be sure.

After that if I try to re-connect to the ksmbd share from macOS, it times out - but then if I restart the ksmbd service (sudo systemctl restart ksmbd), then the macOS clients can connect again.

I'm using the in-kernel ksmbd, and I am on kernel 6.18.6, on Debian Forky, on the ARM64 architecture (Ampere server):

> uname -a
Linux ampere-01 6.16.8+deb14-arm64 #1 SMP PREEMPT Debian 6.16.8-1 (2025-09-21) aarch64 GNU/Linux
> lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux forky/sid
Release:        n/a
Codename:       forky

If I look in the journalctl logs (sudo journalctl --unit ksmbd), I see:

Sep 09 16:55:56 ampere-01 systemd[1]: Stopping ksmbd.service - ksmbd userspace daemon...
Sep 09 16:55:56 ampere-01 ksmbd[1822255]: [ksmbd.mountd(worker)/1822255]: INFO: Terminated
Sep 09 16:55:56 ampere-01 ksmbd[1822254]: [ksmbd.mountd(manager)/1822254]: INFO: Terminated
Sep 09 16:56:03 ampere-01 ksmbd.control[2835645]: [ksmbd.control/2835645]: INFO: Terminated mountd
Sep 09 16:56:03 ampere-01 ksmbd.control[2835645]: [ksmbd.control/2835645]: INFO: Killed ksmbd
Sep 09 16:56:03 ampere-01 systemd[1]: ksmbd.service: Deactivated successfully.
Sep 09 16:56:03 ampere-01 systemd[1]: Stopped ksmbd.service - ksmbd userspace daemon.
Sep 09 16:56:03 ampere-01 systemd[1]: ksmbd.service: Consumed 1.752s CPU time, 3.1M memory peak, 84K memory swap peak.
Sep 09 16:56:03 ampere-01 systemd[1]: Starting ksmbd.service - ksmbd userspace daemon...
Sep 09 16:56:03 ampere-01 ksmbd[2835680]: [ksmbd.mountd/2835680]: INFO: Wrote `/run/ksmbd.lock'
Sep 09 16:56:03 ampere-01 ksmbd.mountd[2835679]: [ksmbd.mountd/2835679]: INFO: Started manager
Sep 09 16:56:03 ampere-01 ksmbd[2835680]: [ksmbd.mountd(manager)/2835680]: INFO: Started worker
Sep 09 16:56:03 ampere-01 systemd[1]: Started ksmbd.service - ksmbd userspace daemon.
Sep 09 16:56:13 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 16:56:13 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 16:56:14 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:44 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:46 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:48 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:49 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:50 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 09 18:25:51 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:45 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 10 04:54:46 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:57 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:57 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:58 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:58 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:58 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:27:59 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 11 13:29:00 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:16 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 21:32:17 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Sep 12 23:27:54 ampere-01 ksmbd[2835681]: [ksmbd.mountd(worker)/2835681]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
lines 1-52

[namjaejeon]

Okay, Can you dump tcpdump(or wireshark) to check packets on problem situation ?

[victorhooi]

OK, I've tried to reproduce the issue, capturing systemctl logs, dmesg, and a tcpdump (attached) during the issue.

Current kernel version is 6.19.9 (Debian, ARM64):

> uname -a
Linux ampere-01 6.16.9+deb14-arm64 #1 SMP PREEMPT Debian 6.16.9-1 (2025-09-27) aarch64 GNU/Linux

For the ksmbd systemcl logs - I can confirm the below messages appear when I first mount the ksmbd volumes - not when it later disconnects. Hence, I'm not sure if they're related to my error?:

Oct 07 13:31:10 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:10 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:11 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:11 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:11 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:11 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52
Oct 07 13:31:11 ampere-01 ksmbd[1856928]: [ksmbd.mountd(worker)/1856928]: ERROR: LSARPC: unsupported INVOKE method 45, alloc_hint : 52

First, I turned on ksmbd debug logging per the instructions here:

> cat /sys/class/ksmbd-control/debug
smb auth vfs oplock ipc conn rdma
> sudo ksmbd.control -d "all"
[sudo] password for victorhooi:
[ksmbd.control/1861845]: INFO: [smb] [auth] [vfs] [oplock] [ipc] [conn] [rdma]
> cat /sys/class/ksmbd-control/debug
[smb] [auth] [vfs] [oplock] [ipc] [conn] [rdma]

I then started took a packet capture per the command below - this should hopefully cover the period where the macOS client was attempting to connect (10.5.1.210 is the client, 10.5.1.132 is the server running ksmbd)):

> sudo tcpdump -i enP6p1s0f0np0 host 10.5.1.210 and host 10.5.1.132 -vv -w trying_to_remount_after_disconnection.pcap
[sudo] password for victorhooi:
tcpdump: listening on enP6p1s0f0np0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
^C3522 packets captured
3540 packets received by filter
0 packets dropped by kernel

I've attached that packet capture. (To be honest, I only saw a single smb2 packet, from server to client - but it's very possible I'm not filtering correctly for the other ksmbd packets - hopefully it has it, let me know if you think I missed capturing something).

There weren't any additional systemctl/journalctl ksmbd log messages printed during the reproduction. However, if I follow dmesg, I can see that ksmbd seems to spit out all its debug messages there:

[ +10.005127] ksmbd: RFC1002 header 344 bytes
[  +0.000194] ksmbd: SMB2 data length 24 offset 128
[  +0.000019] ksmbd: SMB2 len 152
[  +0.000006] ksmbd: Received smb2 create request
[  +0.000059] ksmbd: check permission using windows acl
[  +0.000048] ksmbd: Discard write access to a directory
[  +0.000037] ksmbd: get query on disk id context
[  +0.000027] ksmbd: credits: requested[10] granted[10] total_granted[3805]
[  +0.000009] ksmbd: got SMB2 chained command
[  +0.000004] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000005] ksmbd: SMB2 data length 0 offset 104
[  +0.000004] ksmbd: SMB2 len 105
[  +0.000004] ksmbd: Received request smb2 query info request
[  +0.000007] ksmbd: GOT SMB2_O_INFO_FILESYSTEM
[  +0.000027] ksmbd: credits: requested[10] granted[10] total_granted[3814]
[  +0.000008] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 104 rcv off = 256 rsp off = 312
[  +0.000004] ksmbd: SMB2 len 88
[  +0.000004] ksmbd: Received smb2 close request
[  +0.000004] ksmbd: Compound request set FID = 131:268372
[  +0.000004] ksmbd: volatile_id = 131
[  +0.000012] ksmbd: credits: requested[10] granted[10] total_granted[3823]
[  +0.000005] ksmbd: padding len 4
[ +10.004930] ksmbd: RFC1002 header 344 bytes
[  +0.000229] ksmbd: SMB2 data length 24 offset 128
[  +0.000019] ksmbd: SMB2 len 152
[  +0.000006] ksmbd: Received smb2 create request
[  +0.000056] ksmbd: check permission using windows acl
[  +0.000052] ksmbd: Discard write access to a directory
[  +0.000033] ksmbd: get query on disk id context
[  +0.000024] ksmbd: credits: requested[10] granted[10] total_granted[3832]
[  +0.000007] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000006] ksmbd: SMB2 data length 0 offset 104
[  +0.000006] ksmbd: SMB2 len 105
[  +0.000005] ksmbd: Received request smb2 query info request
[  +0.000013] ksmbd: GOT SMB2_O_INFO_FILESYSTEM
[  +0.000031] ksmbd: credits: requested[10] granted[10] total_granted[3841]
[  +0.000008] ksmbd: got SMB2 chained command
[  +0.000004] ksmbd: Compound req new_len = 104 rcv off = 256 rsp off = 312
[  +0.000005] ksmbd: SMB2 len 88
[  +0.000005] ksmbd: Received smb2 close request
[  +0.000005] ksmbd: Compound request set FID = 132:268373
[  +0.000005] ksmbd: volatile_id = 132
[  +0.000013] ksmbd: credits: requested[10] granted[10] total_granted[3850]
[  +0.000006] ksmbd: padding len 4
[  +1.541230] ksmbd: RFC1002 header 344 bytes
[  +0.000190] ksmbd: SMB2 data length 24 offset 128
[  +0.000019] ksmbd: SMB2 len 152
[  +0.000005] ksmbd: Received smb2 create request
[  +0.000059] ksmbd: check permission using windows acl
[  +0.000047] ksmbd: Discard write access to a directory
[  +0.000030] ksmbd: get query on disk id context
[  +0.000028] ksmbd: credits: requested[10] granted[10] total_granted[3859]
[  +0.000006] ksmbd: got SMB2 chained command
[  +0.000002] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000005] ksmbd: SMB2 data length 0 offset 104
[  +0.000003] ksmbd: SMB2 len 105
[  +0.000005] ksmbd: Received request smb2 query info request
[  +0.000006] ksmbd: GOT SMB2_O_INFO_FILE
[  +0.000005] ksmbd: Compound request set FID = 133
[  +0.000012] ksmbd: filename = \
[  +0.000007] ksmbd: credits: requested[10] granted[10] total_granted[3868]
[  +0.000005] ksmbd: got SMB2 chained command
[  +0.000005] ksmbd: Compound req new_len = 176 rcv off = 256 rsp off = 384
[  +0.000005] ksmbd: SMB2 len 88
[  +0.000004] ksmbd: Received smb2 close request
[  +0.000003] ksmbd: Compound request set FID = 133:268374
[  +0.000003] ksmbd: volatile_id = 133
[  +0.000011] ksmbd: credits: requested[10] granted[10] total_granted[3877]
[  +0.000003] ksmbd: padding len 4
[  +8.463242] ksmbd: RFC1002 header 344 bytes
[  +0.000220] ksmbd: SMB2 data length 24 offset 128
[  +0.000021] ksmbd: SMB2 len 152
[  +0.000006] ksmbd: Received smb2 create request
[  +0.000055] ksmbd: check permission using windows acl
[  +0.000043] ksmbd: Discard write access to a directory
[  +0.000034] ksmbd: get query on disk id context
[  +0.000022] ksmbd: credits: requested[10] granted[10] total_granted[3886]
[  +0.000007] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000006] ksmbd: SMB2 data length 0 offset 104
[  +0.000003] ksmbd: SMB2 len 105
[  +0.000004] ksmbd: Received request smb2 query info request
[  +0.000006] ksmbd: GOT SMB2_O_INFO_FILESYSTEM
[  +0.000026] ksmbd: credits: requested[10] granted[10] total_granted[3895]
[  +0.000005] ksmbd: got SMB2 chained command
[  +0.000002] ksmbd: Compound req new_len = 104 rcv off = 256 rsp off = 312
[  +0.000004] ksmbd: SMB2 len 88
[  +0.000003] ksmbd: Received smb2 close request
[  +0.000002] ksmbd: Compound request set FID = 134:268375
[  +0.000003] ksmbd: volatile_id = 134
[  +0.000010] ksmbd: credits: requested[10] granted[10] total_granted[3904]
[  +0.000003] ksmbd: padding len 4
[  +0.480280] ksmbd: RFC1002 header 344 bytes
[  +0.000167] ksmbd: SMB2 data length 24 offset 128
[  +0.000004] ksmbd: SMB2 len 152
[  +0.000019] ksmbd: Received smb2 create request
[  +0.000054] ksmbd: check permission using windows acl
[  +0.000039] ksmbd: Discard write access to a directory
[  +0.000031] ksmbd: get query on disk id context
[  +0.000020] ksmbd: credits: requested[10] granted[10] total_granted[3913]
[  +0.000005] ksmbd: got SMB2 chained command
[  +0.000002] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000006] ksmbd: SMB2 data length 0 offset 104
[  +0.000003] ksmbd: SMB2 len 105
[  +0.000007] ksmbd: Received request smb2 query info request
[  +0.000006] ksmbd: GOT SMB2_O_INFO_FILESYSTEM
[  +0.000022] ksmbd: credits: requested[10] granted[10] total_granted[3922]
[  +0.000004] ksmbd: got SMB2 chained command
[  +0.000002] ksmbd: Compound req new_len = 104 rcv off = 256 rsp off = 312
[  +0.000003] ksmbd: SMB2 len 88
[  +0.000003] ksmbd: Received smb2 close request
[  +0.000004] ksmbd: Compound request set FID = 135:268376
[  +0.000003] ksmbd: volatile_id = 135
[  +0.000008] ksmbd: credits: requested[10] granted[10] total_granted[3931]
[  +0.000004] ksmbd: padding len 4
[Oct 7 13:40] ksmbd: RFC1002 header 344 bytes
[  +0.000209] ksmbd: SMB2 data length 24 offset 128
[  +0.000020] ksmbd: SMB2 len 152
[  +0.000006] ksmbd: Received smb2 create request
[  +0.000058] ksmbd: check permission using windows acl
[  +0.000049] ksmbd: Discard write access to a directory
[  +0.000033] ksmbd: get query on disk id context
[  +0.000023] ksmbd: credits: requested[10] granted[10] total_granted[3940]
[  +0.000006] ksmbd: got SMB2 chained command
[  +0.000002] ksmbd: Compound req new_len = 208 rcv off = 152 rsp off = 208
[  +0.000006] ksmbd: SMB2 data length 0 offset 104
[  +0.000003] ksmbd: SMB2 len 105
[  +0.000005] ksmbd: Received request smb2 query info request
[  +0.000008] ksmbd: GOT SMB2_O_INFO_FILE
[  +0.000002] ksmbd: Compound request set FID = 136
[  +0.000012] ksmbd: filename = \
[  +0.000008] ksmbd: credits: requested[10] granted[10] total_granted[3949]
[  +0.000003] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 176 rcv off = 256 rsp off = 384
[  +0.000004] ksmbd: SMB2 len 88
[  +0.000003] ksmbd: Received smb2 close request
[  +0.000003] ksmbd: Compound request set FID = 136:268377
[  +0.000004] ksmbd: volatile_id = 136
[  +0.000011] ksmbd: credits: requested[10] granted[10] total_granted[3958]
[  +0.000008] ksmbd: padding len 4
[  +0.000966] ksmbd: RFC1002 header 424 bytes
[  +0.000128] ksmbd: SMB2 data length 24 offset 208
[  +0.000004] ksmbd: SMB2 len 232
[  +0.000014] ksmbd: Received smb2 create request
[  +0.000011] ksmbd: converted name = 6a01c6dd-5b26-7ff5-6a64-1ac4bb64dc28.tmp
[  +0.000029] ksmbd: check permission using windows acl
[  +0.000213] ksmbd: get query on disk id context
[  +0.000111] ksmbd: credits: requested[10] granted[10] total_granted[3967]
[  +0.000010] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 208 rcv off = 232 rsp off = 208
[  +0.000005] ksmbd: SMB2 data length 0 offset 104
[  +0.000002] ksmbd: SMB2 len 105
[  +0.000005] ksmbd: Received request smb2 query info request
[  +0.000012] ksmbd: GOT SMB2_O_INFO_FILE
[  +0.000003] ksmbd: Compound request set FID = 137
[  +0.000011] ksmbd: filename = \6a01c6dd-5b26-7ff5-6a64-1ac4bb64dc28.tmp
[  +0.000009] ksmbd: credits: requested[10] granted[10] total_granted[3976]
[  +0.000003] ksmbd: got SMB2 chained command
[  +0.000003] ksmbd: Compound req new_len = 256 rcv off = 336 rsp off = 464
[  +0.000005] ksmbd: SMB2 len 88
[  +0.000003] ksmbd: Received smb2 close request
[  +0.000005] ksmbd: Compound request set FID = 137:268378
[  +0.000003] ksmbd: volatile_id = 137
[  +0.000009] ksmbd: credits: requested[10] granted[10] total_granted[3985]
[  +0.000004] ksmbd: padding len 4
[  +0.000292] ksmbd: RFC1002 header 272 bytes
[  +0.000044] ksmbd: SMB2 data length 64 offset 208
[  +0.000008] ksmbd: SMB2 len 272
[  +0.000003] ksmbd: Received smb2 create request
[  +0.000009] ksmbd: converted name = 6a01c6dd-5b26-7ff5-6a64-1ac4bb64dc28.tmp
[  +0.000026] ksmbd: check permission using windows acl
[  +0.000137] ksmbd: get query on disk id context
[  +0.000101] ksmbd: credits: requested[10] granted[10] total_granted[3994]
[  +0.000301] ksmbd: RFC1002 header 88 bytes
[  +0.000038] ksmbd: SMB2 len 88
[  +0.000009] ksmbd: Received smb2 close request
[  +0.000003] ksmbd: volatile_id = 138
[  +0.000021] ksmbd: credits: requested[10] granted[10] total_granted[4003]
[  +0.000383] ksmbd: RFC1002 header 344 bytes
[  +0.000124] ksmbd: SMB2 data length 24 offset 128
[  +0.000005] ksmbd: SMB2 len 152
[  +0.000007] ksmbd: Received smb2 create request
[  +0.000037] ksmbd: check permission using windows acl
[  +0.000030] ksmbd: Discard write access to a directory
[  +0.000021] ksmbd: get query on disk id context

trying_to_remount_after_disconnection.pcap.zip

[victorhooi]

Also, I think this might be the dmesg messages when the ksmbd server forcefully disconnects the client:

[Oct 7 14:11] ksmbd: Unsupported RPC: mdssvc
[  +0.000024] ksmbd: Unable to open RPC pipe: -22
[  +0.205931] ksmbd: Unsupported RPC: mdssvc
[  +0.000027] ksmbd: Unable to open RPC pipe: -22
[  +0.040366] ksmbd: Unsupported RPC: MsFteWds
[  +0.000023] ksmbd: Unable to open RPC pipe: -22
[  +0.366110] ksmbd: Unsupported RPC: mdssvc
[  +0.000025] ksmbd: Unable to open RPC pipe: -22
[  +0.082372] ksmbd: Unsupported RPC: MsFteWds
[  +0.000020] ksmbd: Unable to open RPC pipe: -22
[  +0.283340] ksmbd: Unsupported RPC: mdssvc
[  +0.000049] ksmbd: Unable to open RPC pipe: -22
[  +0.080888] ksmbd: Unsupported RPC: MsFteWds
[  +0.000020] ksmbd: Unable to open RPC pipe: -22
[  +0.283834] ksmbd: Unsupported RPC: mdssvc
[  +0.000018] ksmbd: Unable to open RPC pipe: -22
[  +0.080489] ksmbd: Unsupported RPC: MsFteWds
[  +0.000033] ksmbd: Unable to open RPC pipe: -22
[  +0.366179] ksmbd: Unsupported RPC: MsFteWds
[  +0.000047] ksmbd: Unable to open RPC pipe: -22
[  +0.040638] ksmbd: Unsupported RPC: mdssvc
[  +0.000040] ksmbd: Unable to open RPC pipe: -22
[  +0.326399] ksmbd: Unsupported RPC: mdssvc
[  +0.000026] ksmbd: Unable to open RPC pipe: -22
[  +0.042839] ksmbd: Unsupported RPC: MsFteWds
[  +0.000023] ksmbd: Unable to open RPC pipe: -22
[  +0.281648] ksmbd: Unsupported RPC: MsFteWds
[  +0.000028] ksmbd: Unable to open RPC pipe: -22

[namjaejeon]

@victorhooi Sorry, You didn't capture packets correctly. So I can't figure anything out with this dump. I'd like to know if your issue can happen with the latest ksmbd source.

If you don't check 6.18-rc1 kernel(or the latest linus tree), can you check the following out of tree ksmbd source?

git clone https://github.com/namjaejeon/ksmbd

[mmakassikis]

The "Unsupported RPC" messages are not a problem. They appear because the client is probing for Spotlight/indexing support on the server.

Can you try with the patch I just sent on the mailing list ?

https://lore.kernel.org/linux-cifs/20251015072546.3941890-1-mmakassikis@freebox.fr/T/#u

[namjaejeon]

@mmakassikis Your patch have been applied into mainline now. (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/smb/server?id=88f170814fea74911ceab798a43cbd7c5599bed4")

@victorhooi Can you check your issue with this patch ? or try 6.18-rc2 kernel that is coming soon.