Hi everyone,
I'm having problems with CIFS connections to our NAS. The vendor
inspected the problem and claimed the Linux CIFS module doesn't follow
the specifications, which causes the instabilities + shutdown problems
with our LiMux clients in our SMB2+ tests.
Quoting http://msdn.microsoft.com/en-us/library/cc246529.aspx:
"TreeId (4 bytes): Uniquely identifies the tree connect for the
command. This MUST be 0 for the SMB2 TREE_CONNECT Request."
I applied the attached "warn" diff, which resulted in the (expected)
following stack trace (albeit for an old Ubuntu kernel), but otherwise
fixes the problem.
[ 1815.635274] ------------[ cut here ]------------
[ 1815.635294] WARNING: CPU: 1 PID: 65 at
/tmp/cifs-3.13.0-100.147-patched/smb2pdu.c:164
small_smb2_init+0x246/0x560 [cifs]()
[ 1815.635295] smb2_reconnect: SMB2_TREE_CONNECT with tid != 0
[ 1815.635296] Modules linked in: nls_iso8859_1 usb_storage arc4 md4
nls_utf8 cifs(OX) fscache kav4fs_oas(OX) redirfs(OX) dm_crypt rfcomm
bnep bluetooth x86_pkg_temp_thermal intel_powerclamp coretemp
snd_hda_codec_hdmi snd_hda_codec_realtek kvm_intel kvm joydev
snd_hda_intel snd_hda_codec snd_hwdep crc32_pclmul snd_pcm
snd_page_alloc serio_raw snd_seq_midi snd_seq_midi_event lpc_ich ipmi_si
snd_rawmidi snd_seq snd_seq_device snd_timer parport_pc ppdev snd shpchp
lp mac_hid soundcore parport hid_generic usbhid hid i915 i2c_algo_bit
drm_kms_helper ahci drm r8169 libahci psmouse mii wmi video
[ 1815.635327] CPU: 1 PID: 65 Comm: kworker/1:2 Tainted: G W OX
3.13.0-100-generic #147-Ubuntu
[ 1815.635328] Hardware name: Acer Veriton M4630G/Veriton M4630G, BIOS
P11-C1L 04/10/2015
[ 1815.635344] Workqueue: cifsiod cifs_writev_complete [cifs]
[ 1815.635346] 00000286 00000286 f65edd68 c165dcd2 f65edda8 f8cd0f78
f65edd98 c105798e
[ 1815.635350] f8cd102c f65eddc4 00000041 f8cd0f78 000000a4 f8cb1df6
f8cb1df6 f4347800
[ 1815.635353] 00000044 f4452c00 f65eddb0 c10579e3 00000009 f65edda8
f8cd102c f65eddc4
[ 1815.635357] Call Trace:
[ 1815.635362] [<c165dcd2>] dump_stack+0x58/0x72
[ 1815.635366] [<c105798e>] warn_slowpath_common+0x7e/0xa0
[ 1815.635378] [<f8cb1df6>] ? small_smb2_init+0x246/0x560 [cifs]
[ 1815.635390] [<f8cb1df6>] ? small_smb2_init+0x246/0x560 [cifs]
[ 1815.635392] [<c10579e3>] warn_slowpath_fmt+0x33/0x40
[ 1815.635404] [<f8cb1df6>] small_smb2_init+0x246/0x560 [cifs]
[ 1815.635416] [<f8ca1b80>] ? cifs_strtoUTF16+0xc0/0xf0 [cifs]
[ 1815.635427] [<f8cb17f9>] SMB2_tcon+0xb9/0x470 [cifs]
[ 1815.635438] [<f8cb2580>] ? SMB2_negotiate+0x470/0x470 [cifs]
[ 1815.635449] [<f8cb1fc5>] small_smb2_init+0x415/0x560 [cifs]
[ 1815.635452] [<c1092ca0>] ? prepare_to_wait_event+0xd0/0xd0
[ 1815.635464] [<f8cb45c4>] smb2_async_writev+0x34/0x1d0 [cifs]
[ 1815.635475] [<f8c7a8ae>] ? cifs_writedata_release+0x1e/0x30 [cifs]
[ 1815.635478] [<c112d547>] ? clear_page_dirty_for_io+0x57/0xe0
[ 1815.635488] [<f8c7de3a>] cifs_writev_complete+0x1aa/0x270 [cifs]
[ 1815.635491] [<c10702ba>] process_one_work+0x11a/0x3c0
[ 1815.635493] [<c1070f49>] worker_thread+0xf9/0x380
[ 1815.635495] [<c1070e50>] ? rescuer_thread+0x380/0x380
[ 1815.635497] [<c10767cb>] kthread+0x9b/0xb0
[ 1815.635500] [<c166c037>] ret_from_kernel_thread+0x1b/0x28
[ 1815.635503] [<c1076730>] ? kthread_create_on_node+0x140/0x140
[ 1815.635504] ---[ end trace d45909fef64cdfda ]---
[ 1815.655889] cifs_vfs_err: 2516 callbacks suppressed
[ 1815.655893] CIFS VFS: cifs_invalidate_mapping: could not invalidate
inode d92e3798
I don't know if we want to zero tcon for new connections / reconnects.
The "warn" diff was tested by a colleague and "works for him".
Thanks,
Jan-Marek
P.S. The 2nd patch without the warning was just compile-tested.
--- smb2pdu.c.orig 2017-01-20 19:58:34.581064153 +0100
+++ smb2pdu.c 2017-01-20 20:19:23.124772222 +0100
@@ -172,7 +172,14 @@
return rc;
if (smb2_command == SMB2_TREE_CONNECT)
+ {
+ if (tcon->tid != 0)
+ {
+ WARN(1, "%s: SMB2_TREE_CONNECT with tid != 0\n", __func__);
+ tcon->tid = 0;
+ }
return rc;
+ }
if (tcon->tidStatus == CifsExiting) {
/*
>From 249ab089b1c83dfbe22a1a0b37395ccd394ae1ad Mon Sep 17 00:00:00 2001
From: Jan-Marek Glogowski <glogow@xxxxxxxxxx>
Date: Fri, 10 Feb 2017 16:43:46 +0100
Subject: [PATCH] Reset TreeId to zero on SMB2_TREE_CONNECT
Currently the cifs module breaks the CIFS specs as described in
http://msdn.microsoft.com/en-us/library/cc246529.aspx:
"TreeId (4 bytes): Uniquely identifies the tree connect for the
command. This MUST be 0 for the SMB2 TREE_CONNECT Request."
Signed-off-by: Jan-Marek Glogowski <glogow@xxxxxxxxxx>
---
fs/cifs/smb2pdu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 8745722..ad1b555 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -169,7 +169,10 @@
return rc;
if (smb2_command == SMB2_TREE_CONNECT)
+ {
+ tcon->tid = 0;
return rc;
+ }
if (tcon->tidStatus == CifsExiting) {
/*
--
1.9.1
