From 0680810c11fe16e7f8797908c8cb94e6a4933cbd Mon Sep 17 00:00:00 2001 From: Eddie Wai Date: Wed, 25 Sep 2013 22:01:20 -0700 Subject: [PATCH] [SCSI] BNX2FC: hung task timeout warning observed when rmmod bnx2x with active FCoE targets [v2] - removed the interface->enabled flag setting which prevented the fcoe ctlr link from being brought back up after a MTU change A rtnl_lock deadlock was observed from the rmmod thread where it tries to unregister the fcoe_ctlr device. This unregistration triggered a flush of the sysfs queue of the associated ctlr and led to a call to the set_fcoe_ctlr_enabled routine. This will eventually propagate down to call the bnx2fc_disable routine and contented for the rtnl_lock in the same context. This patch creates a subset of the bnx2fc_enable/disable routine which removes the unnecesary rtnl_lock and the bnx2fc_dev_lock acquisition from the set_fcoe_ctlr_enabled path. kernel: INFO: task rmmod:7874 blocked for more than 120 seconds. kernel: Tainted: G W --------------- 2.6.32-415.0.1.el6.x86_64 #1 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: rmmod D 000000000000000f 0 7874 6518 0x00000080 kernel: ffff88022158f7d8 0000000000000086 0000000000000000 0000000000000000 kernel: ffff88023fe72600 ffff88043c74d410 ffff88043c74d400 ffff88043c74d000 kernel: ffff88021ecbe5f8 ffff88022158ffd8 000000000000fbc8 ffff88021ecbe5f8 kernel: Call Trace: kernel: [] schedule_timeout+0x215/0x2e0 kernel: [] ? pick_next_task_fair+0xd0/0x130 kernel: [] ? schedule+0x178/0x3b2 kernel: [] wait_for_common+0x123/0x180 kernel: [] ? default_wake_function+0x0/0x20 kernel: [] ? ifind_fast+0x5e/0xb0 kernel: [] wait_for_completion+0x1d/0x20 kernel: [] sysfs_addrm_finish+0x228/0x270 kernel: [] sysfs_hash_and_remove+0x5b/0x90 kernel: [] sysfs_remove_group+0x5f/0x100 kernel: [] device_remove_groups+0x3b/0x60 kernel: [] device_remove_attrs+0x3d/0x90 kernel: [] device_del+0x125/0x1e0 kernel: [] device_unregister+0x22/0x60 kernel: [] fcoe_ctlr_device_delete+0xe2/0xf4 [libfcoe] kernel: [] bnx2fc_interface_release+0x5b/0x90 [bnx2fc] kernel: [] ? bnx2fc_interface_release+0x0/0x90 [bnx2fc] kernel: [] kref_put+0x37/0x70 kernel: [] __bnx2fc_destroy+0x72/0xa0 [bnx2fc] kernel: [] bnx2fc_ulp_exit+0xf5/0x160 [bnx2fc] <- got bnx2fc_dev_lock mutex_lock kernel: [] cnic_ulp_exit+0xb6/0xc0 [cnic] kernel: [] cnic_netdev_event+0x368/0x370 [cnic] kernel: [] ? fcoe_del_netdev_mapping+0x8c/0xa0 [libfcoe] kernel: [] notifier_call_chain+0x55/0x80 kernel: [] raw_notifier_call_chain+0x16/0x20 kernel: [] call_netdevice_notifiers+0x1b/0x20 kernel: [] rollback_registered_many+0x154/0x280 kernel: [] rollback_registered+0x38/0x50 kernel: [] unregister_netdevice_queue+0x58/0xa0 kernel: [] unregister_netdevice+0x10/0x20 kernel: [] unregister_netdev+0x1e/0x30 <- got rtnl_lock!!!!!!!!! kernel: [] __bnx2x_remove+0x48/0x270 [bnx2x] <- got & rel rtnl_lock kernel: [] bnx2x_remove_one+0x44/0x80 [bnx2x] kernel: [] pci_device_remove+0x37/0x70 kernel: [] __device_release_driver+0x6f/0xe0 kernel: [] driver_detach+0xc8/0xd0 kernel: [] bus_remove_driver+0x8e/0x110 kernel: [] driver_unregister+0x62/0xa0 kernel: [] pci_unregister_driver+0x44/0xb0 kernel: [] bnx2x_cleanup+0x18/0x73 [bnx2x] kernel: [] sys_delete_module+0x194/0x260 kernel: [] ? audit_syscall_entry+0x1d7/0x200 kernel: [] system_call_fastpath+0x16/0x1b Signed-off-by: Eddie Wai Signed-off-by: James Bottomley --- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 63 ++++++++++++++++++++++--------- 1 file changed, 46 insertions(+), 17 deletions(-) diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index 69ac55495c1d..7a25766b0fcd 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -2004,6 +2004,24 @@ static void bnx2fc_ulp_init(struct cnic_dev *dev) set_bit(BNX2FC_CNIC_REGISTERED, &hba->reg_with_cnic); } +/* Assumes rtnl_lock and the bnx2fc_dev_lock are already taken */ +static int __bnx2fc_disable(struct fcoe_ctlr *ctlr) +{ + struct bnx2fc_interface *interface = fcoe_ctlr_priv(ctlr); + + if (interface->enabled == true) { + if (!ctlr->lp) { + pr_err(PFX "__bnx2fc_disable: lport not found\n"); + return -ENODEV; + } else { + interface->enabled = false; + fcoe_ctlr_link_down(ctlr); + fcoe_clean_pending_queue(ctlr->lp); + } + } + return 0; +} + /** * Deperecated: Use bnx2fc_enabled() */ @@ -2018,20 +2036,34 @@ static int bnx2fc_disable(struct net_device *netdev) interface = bnx2fc_interface_lookup(netdev); ctlr = bnx2fc_to_ctlr(interface); - if (!interface || !ctlr->lp) { - rc = -ENODEV; - printk(KERN_ERR PFX "bnx2fc_disable: interface or lport not found\n"); - } else { - interface->enabled = false; - fcoe_ctlr_link_down(ctlr); - fcoe_clean_pending_queue(ctlr->lp); - } + if (!interface) { + rc = -ENODEV; + pr_err(PFX "bnx2fc_disable: interface not found\n"); + } else { + rc = __bnx2fc_disable(ctlr); + } mutex_unlock(&bnx2fc_dev_lock); rtnl_unlock(); return rc; } +static int __bnx2fc_enable(struct fcoe_ctlr *ctlr) +{ + struct bnx2fc_interface *interface = fcoe_ctlr_priv(ctlr); + + if (interface->enabled == false) { + if (!ctlr->lp) { + pr_err(PFX "__bnx2fc_enable: lport not found\n"); + return -ENODEV; + } else if (!bnx2fc_link_ok(ctlr->lp)) { + fcoe_ctlr_link_up(ctlr); + interface->enabled = true; + } + } + return 0; +} + /** * Deprecated: Use bnx2fc_enabled() */ @@ -2046,12 +2078,11 @@ static int bnx2fc_enable(struct net_device *netdev) interface = bnx2fc_interface_lookup(netdev); ctlr = bnx2fc_to_ctlr(interface); - if (!interface || !ctlr->lp) { + if (!interface) { rc = -ENODEV; - printk(KERN_ERR PFX "bnx2fc_enable: interface or lport not found\n"); - } else if (!bnx2fc_link_ok(ctlr->lp)) { - fcoe_ctlr_link_up(ctlr); - interface->enabled = true; + pr_err(PFX "bnx2fc_enable: interface not found\n"); + } else { + rc = __bnx2fc_enable(ctlr); } mutex_unlock(&bnx2fc_dev_lock); @@ -2072,14 +2103,12 @@ static int bnx2fc_enable(struct net_device *netdev) static int bnx2fc_ctlr_enabled(struct fcoe_ctlr_device *cdev) { struct fcoe_ctlr *ctlr = fcoe_ctlr_device_priv(cdev); - struct fc_lport *lport = ctlr->lp; - struct net_device *netdev = bnx2fc_netdev(lport); switch (cdev->enabled) { case FCOE_CTLR_ENABLED: - return bnx2fc_enable(netdev); + return __bnx2fc_enable(ctlr); case FCOE_CTLR_DISABLED: - return bnx2fc_disable(netdev); + return __bnx2fc_disable(ctlr); case FCOE_CTLR_UNUSED: default: return -ENOTSUPP;