[PATCH v2 10/16] smb: client: fix warning when reconnecting channel

[David Howells]

From: Paulo Alcantara <pc at manguebit.org>

When reconnecting a channel in smb2_reconnect_server(), a dummy tcon
is passed down to smb2_reconnect() with ->query_interface
uninitialized, so we can't call queue_delayed_work() on it.

Fix the following warning by ensuring that we're queueing the delayed
worker from correct tcon.

WARNING: CPU: 4 PID: 1126 at kernel/workqueue.c:2498 __queue_delayed_work+0x1d2/0x200
Modules linked in: cifs cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs]
CPU: 4 UID: 0 PID: 1126 Comm: kworker/4:0 Not tainted 6.16.0-rc3 #5 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-4.fc42 04/01/2014
Workqueue: cifsiod smb2_reconnect_server [cifs]
RIP: 0010:__queue_delayed_work+0x1d2/0x200
Code: 41 5e 41 5f e9 7f ee ff ff 90 0f 0b 90 e9 5d ff ff ff bf 02 00
00 00 e8 6c f3 07 00 89 c3 eb bd 90 0f 0b 90 e9 57 f> 0b 90 e9 65 fe
ff ff 90 0f 0b 90 e9 72 fe ff ff 90 0f 0b 90 e9
RSP: 0018:ffffc900014afad8 EFLAGS: 00010003
RAX: 0000000000000000 RBX: ffff888124d99988 RCX: ffffffff81399cc1
RDX: dffffc0000000000 RSI: ffff888114326e00 RDI: ffff888124d999f0
RBP: 000000000000ea60 R08: 0000000000000001 R09: ffffed10249b3331
R10: ffff888124d9998f R11: 0000000000000004 R12: 0000000000000040
R13: ffff888114326e00 R14: ffff888124d999d8 R15: ffff888114939020
FS:  0000000000000000(0000) GS:ffff88829f7fe000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7a2b4038 CR3: 0000000120a6f000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 <TASK>
 queue_delayed_work_on+0xb4/0xc0
 smb2_reconnect+0xb22/0xf50 [cifs]
 smb2_reconnect_server+0x413/0xd40 [cifs]
 ? __pfx_smb2_reconnect_server+0x10/0x10 [cifs]
 ? local_clock_noinstr+0xd/0xd0
 ? local_clock+0x15/0x30
 ? lock_release+0x29b/0x390
 process_one_work+0x4c5/0xa10
 ? __pfx_process_one_work+0x10/0x10
 ? __list_add_valid_or_report+0x37/0x120
 worker_thread+0x2f1/0x5a0
 ? __kthread_parkme+0xde/0x100
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x1fe/0x380
 ? kthread+0x10f/0x380
 ? __pfx_kthread+0x10/0x10
 ? local_clock_noinstr+0xd/0xd0
 ? ret_from_fork+0x1b/0x1f0
 ? local_clock+0x15/0x30
 ? lock_release+0x29b/0x390
 ? rcu_is_watching+0x20/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x15b/0x1f0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>
irq event stamp: 1116206
hardirqs last  enabled at (1116205): [<ffffffff8143af42>] __up_console_sem+0x52/0x60
hardirqs last disabled at (1116206): [<ffffffff81399f0e>] queue_delayed_work_on+0x6e/0xc0
softirqs last  enabled at (1116138): [<ffffffffc04562fd>] __smb_send_rqst+0x42d/0x950 [cifs]
softirqs last disabled at (1116136): [<ffffffff823d35e1>] release_sock+0x21/0xf0

Cc: linux-cifs at vger.kernel.org
Reported-by: David Howells <dhowells at redhat.com>
Fixes: 42ca547b13a2 ("cifs: do not disable interface polling on failure")
Reviewed-by: David Howells <dhowells at redhat.com>
Tested-by: David Howells <dhowells at redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc at manguebit.org>
Signed-off-by: David Howells <dhowells at redhat.com>
---
 fs/smb/client/cifsglob.h |  1 +
 fs/smb/client/smb2pdu.c  | 10 ++++------
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 45e94e18f4d5..da963294a573 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1302,6 +1302,7 @@ struct cifs_tcon {
 	bool use_persistent:1; /* use persistent instead of durable handles */
 	bool no_lease:1;    /* Do not request leases on files or directories */
 	bool use_witness:1; /* use witness protocol */
+	bool dummy:1; /* dummy tcon used for reconnecting channels */
 	__le32 capabilities;
 	__u32 share_flags;
 	__u32 maximal_access;
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 084ee66e73fd..572cfc42dda8 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -424,9 +424,9 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 		free_xid(xid);
 		ses->flags &= ~CIFS_SES_FLAGS_PENDING_QUERY_INTERFACES;
 
-		/* regardless of rc value, setup polling */
-		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
-				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
+		if (!tcon->ipc && !tcon->dummy)
+			queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
+					   (SMB_INTERFACE_POLL_INTERVAL * HZ));
 
 		mutex_unlock(&ses->session_mutex);
 
@@ -4229,10 +4229,8 @@ void smb2_reconnect_server(struct work_struct *work)
 		}
 		goto done;
 	}
-
 	tcon->status = TID_GOOD;
-	tcon->retry = false;
-	tcon->need_reconnect = false;
+	tcon->dummy = true;
 
 	/* now reconnect sessions for necessary channels */
 	list_for_each_entry_safe(ses, ses2, &tmp_ses_list, rlist) {