RE: [EXT] [PATCH V2] scsi: bnx2fc: flush destroy_work queue before calling bnx2fc_interface_put

[Saurav Kashyap]

Hi John,


> -----Original Message-----
> From: John Meneghini <jmeneghi@xxxxxxxxxx>
> Sent: Friday, January 14, 2022 10:34 PM
> To: linux-scsi@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; GR-QLogic-Storage-Upstream <GR-QLogic-
> Storage-Upstream@xxxxxxxxxxx>; mlombard@xxxxxxxxxx; Saurav Kashyap
> <skashyap@xxxxxxxxxxx>
> Subject: [EXT] [PATCH V2] scsi: bnx2fc: flush destroy_work queue before calling
> bnx2fc_interface_put
> 
> External Email
> 
> ----------------------------------------------------------------------
>   The bnx2fc_destroy functions are removing the interface before calling
>   destroy_work. This results multiple WARNings from sysfs_remove_group
>   as the controller rport device attributes are removed to early.
> 
>   Replace the fcoe_port's destroy_work queue.  It's not needed.
> 
>   The problem is easily reproducible with the following steps.
> 
>   Example:
> 
>     $ dmesg -w &
>     $ systemctl enable --now fcoe
>     $ fipvlan -s -c ens2f1
>     $ fcoeadm -d ens2f1.802
>     [  583.464488] host2: libfc: Link down on port (7500a1)
>     [  583.472651] bnx2fc: 7500a1 - rport not created Yet!!
>     [  583.490468] ------------[ cut here ]------------
>     [  583.538725] sysfs group 'power' not found for kobject 'rport-2:0-0'
>     [  583.568814] WARNING: CPU: 3 PID: 192 at fs/sysfs/group.c:279
> sysfs_remove_group+0x6f/0x80
>     [  583.607130] Modules linked in: dm_service_time 8021q garp mrp stp llc
> bnx2fc cnic uio rpcsec_gss_krb5 auth_rpcgss nfsv4 ...
>     [  583.942994] CPU: 3 PID: 192 Comm: kworker/3:2 Kdump: loaded Not
> tainted 5.14.0-39.el9.x86_64 #1
>     [  583.984105] Hardware name: HP ProLiant DL120 G7, BIOS J01 07/01/2013
>     [  584.016535] Workqueue: fc_wq_2 fc_rport_final_delete
> [scsi_transport_fc]
>     [  584.050691] RIP: 0010:sysfs_remove_group+0x6f/0x80
>     [  584.074725] Code: ff 5b 48 89 ef 5d 41 5c e9 ee c0 ff ff 48 89 ef e8 f6 b8 ff
> ff eb d1 49 8b 14 24 48 8b 33 48 c7 c7 ...
>     [  584.162586] RSP: 0018:ffffb567c15afdc0 EFLAGS: 00010282
>     [  584.188225] RAX: 0000000000000000 RBX: ffffffff8eec4220 RCX:
> 0000000000000000
>     [  584.221053] RDX: ffff8c1586ce84c0 RSI: ffff8c1586cd7cc0 RDI:
> ffff8c1586cd7cc0
>     [  584.255089] RBP: 0000000000000000 R08: 0000000000000000 R09:
> ffffb567c15afc00
>     [  584.287954] R10: ffffb567c15afbf8 R11: ffffffff8fbe7f28 R12:
> ffff8c1486326400
>     [  584.322356] R13: ffff8c1486326480 R14: ffff8c1483a4a000 R15:
> 0000000000000004
>     [  584.355379] FS:  0000000000000000(0000) GS:ffff8c1586cc0000(0000)
> knlGS:0000000000000000
>     [  584.394419] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>     [  584.421123] CR2: 00007fe95a6f7840 CR3: 0000000107674002 CR4:
> 00000000000606e0
>     [  584.454888] Call Trace:
>     [  584.466108]  device_del+0xb2/0x3e0
>     [  584.481701]  device_unregister+0x13/0x60
>     [  584.501306]  bsg_unregister_queue+0x5b/0x80
>     [  584.522029]  bsg_remove_queue+0x1c/0x40
>     [  584.541884]  fc_rport_final_delete+0xf3/0x1d0 [scsi_transport_fc]
>     [  584.573823]  process_one_work+0x1e3/0x3b0
>     [  584.592396]  worker_thread+0x50/0x3b0
>     [  584.609256]  ? rescuer_thread+0x370/0x370
>     [  584.628877]  kthread+0x149/0x170
>     [  584.643673]  ? set_kthread_struct+0x40/0x40
>     [  584.662909]  ret_from_fork+0x22/0x30
>     [  584.680002] ---[ end trace 53575ecefa942ece ]---
> 
> Signed-off-by: John Meneghini <jmeneghi@xxxxxxxxxx>
> Signed-off-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
> ---
>  drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 20 +++++---------------
>  1 file changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> index 71fa62bd3083..9be273c320e2 100644
> --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> @@ -82,7 +82,7 @@ static int bnx2fc_bind_pcidev(struct bnx2fc_hba *hba);
>  static void bnx2fc_unbind_pcidev(struct bnx2fc_hba *hba);
>  static struct fc_lport *bnx2fc_if_create(struct bnx2fc_interface *interface,
>  				  struct device *parent, int npiv);
> -static void bnx2fc_destroy_work(struct work_struct *work);
> +static void bnx2fc_port_destroy(struct fcoe_port *port);
> 
>  static struct bnx2fc_hba *bnx2fc_hba_lookup(struct net_device *phys_dev);
>  static struct bnx2fc_interface *bnx2fc_interface_lookup(struct net_device
> @@ -907,9 +907,6 @@ static void bnx2fc_indicate_netevent(void *context,
> unsigned long event,
>  				__bnx2fc_destroy(interface);
>  		}
>  		mutex_unlock(&bnx2fc_dev_lock);
> -
> -		/* Ensure ALL destroy work has been completed before return
> */
> -		flush_workqueue(bnx2fc_wq);
>  		return;
> 
>  	default:
> @@ -1215,8 +1212,8 @@ static int bnx2fc_vport_destroy(struct fc_vport
> *vport)
>  	mutex_unlock(&n_port->lp_mutex);
>  	bnx2fc_free_vport(interface->hba, port->lport);
>  	bnx2fc_port_shutdown(port->lport);
> +	bnx2fc_port_destroy(port);
>  	bnx2fc_interface_put(interface);
> -	queue_work(bnx2fc_wq, &port->destroy_work);
>  	return 0;
>  }
> 
> @@ -1525,7 +1522,6 @@ static struct fc_lport *bnx2fc_if_create(struct
> bnx2fc_interface *interface,
>  	port->lport = lport;
>  	port->priv = interface;
>  	port->get_netdev = bnx2fc_netdev;
> -	INIT_WORK(&port->destroy_work, bnx2fc_destroy_work);
> 
>  	/* Configure fcoe_port */
>  	rc = bnx2fc_lport_config(lport);
> @@ -1653,8 +1649,8 @@ static void __bnx2fc_destroy(struct bnx2fc_interface
> *interface)
>  	bnx2fc_interface_cleanup(interface);
>  	bnx2fc_stop(interface);
>  	list_del(&interface->list);
> +	bnx2fc_port_destroy(port);
>  	bnx2fc_interface_put(interface);
> -	queue_work(bnx2fc_wq, &port->destroy_work);
>  }
> 
>  /**
> @@ -1694,15 +1690,12 @@ static int bnx2fc_destroy(struct net_device
> *netdev)
>  	return rc;
>  }
> 
> -static void bnx2fc_destroy_work(struct work_struct *work)
> +static void bnx2fc_port_destroy(struct fcoe_port *port)
>  {
> -	struct fcoe_port *port;
>  	struct fc_lport *lport;
> 
> -	port = container_of(work, struct fcoe_port, destroy_work);
>  	lport = port->lport;
> -
> -	BNX2FC_HBA_DBG(lport, "Entered bnx2fc_destroy_work\n");
> +	BNX2FC_HBA_DBG(lport, "Entered %s, destroying lport %p\n",
> __func__, lport);
> 
>  	bnx2fc_if_destroy(lport);
>  }
> @@ -2556,9 +2549,6 @@ static void bnx2fc_ulp_exit(struct cnic_dev *dev)
>  			__bnx2fc_destroy(interface);
>  	mutex_unlock(&bnx2fc_dev_lock);
> 
> -	/* Ensure ALL destroy work has been completed before return */
> -	flush_workqueue(bnx2fc_wq);
> -
>  	bnx2fc_ulp_stop(hba);
>  	/* unregister cnic device */
>  	if (test_and_clear_bit(BNX2FC_CNIC_REGISTERED, &hba-
> >reg_with_cnic))
> --

Thanks for the patch.
Acked-by: Saurav Kashyap <skashyap@xxxxxxxxxxx>

Thanks,
~Saurav
> 2.27.0