Fixes reference counting on fcoe_instance and net_device, and adds NETDEV_UNREGISTER notifier handling so that you can unload network drivers. FCoE no longer increments the module use count for the network driver.
On an NETDEV_UNREGISTER event, destroying the FCoE instance is deferred to a workqueue context to avoid RTNL deadlocks. Based in part by an earlier patch from John Fastabend John's patch description: Currently, the netdev module ref count is not decremented with module_put() when the module is unloaded while fcoe instances are present. To fix this removed reference count on netdev module completely and added functionality to netdev event handling for NETDEV_UNREGISTER events. This allows fcoe to remove devices cleanly when the netdev module is unloaded so we no longer need to hold a reference count for the netdev module. Signed-off-by: Chris Leech <[email protected]> --- drivers/scsi/fcoe/fcoe.c | 175 +++++++++++++++------------------------------- drivers/scsi/fcoe/fcoe.h | 2 + 2 files changed, 58 insertions(+), 119 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 2330403..290baaa 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -74,12 +74,13 @@ static int fcoe_link_ok(struct fc_lport *lp); static struct fc_lport *fcoe_hostlist_lookup(const struct net_device *); static int fcoe_hostlist_add(const struct fc_lport *); -static int fcoe_hostlist_remove(const struct fc_lport *); static void fcoe_check_wait_queue(struct fc_lport *, struct sk_buff *); static int fcoe_device_notification(struct notifier_block *, ulong, void *); static void fcoe_dev_setup(void); static void fcoe_dev_cleanup(void); +static struct fcoe_interface * + fcoe_hostlist_lookup_port(const struct net_device *dev); /* notification function from net device */ static struct notifier_block fcoe_notifier = { @@ -216,6 +217,7 @@ static int fcoe_interface_setup(struct fcoe_interface *fcoe, static void fcoe_fip_send(struct fcoe_ctlr *fip, struct sk_buff *skb); static void fcoe_update_src_mac(struct fcoe_ctlr *fip, u8 *old, u8 *new); +static void fcoe_destroy_work(struct work_struct *work); /** * fcoe_interface_create() @@ -233,6 +235,7 @@ static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev) return NULL; } + dev_hold(netdev); kref_init(&fcoe->kref); /* @@ -289,10 +292,13 @@ void fcoe_interface_cleanup(struct fcoe_interface *fcoe) static void fcoe_interface_release(struct kref *kref) { struct fcoe_interface *fcoe; + struct net_device *netdev; fcoe = container_of(kref, struct fcoe_interface, kref); + netdev = fcoe->netdev; fcoe_interface_cleanup(fcoe); kfree(fcoe); + dev_put(netdev); } /** @@ -643,8 +649,7 @@ static void fcoe_if_destroy(struct fc_lport *lport) /* Free memory used by statistical counters */ fc_lport_free_stats(lport); - /* Release the net_device and Scsi_Host */ - dev_put(netdev); + /* Release the Scsi_Host */ scsi_host_put(lport->host); } @@ -719,7 +724,9 @@ static struct fc_lport *fcoe_if_create(struct fcoe_interface *fcoe, } lport = shost_priv(shost); port = lport_priv(lport); + port->lport = lport; port->fcoe = fcoe; + INIT_WORK(&port->destroy_work, fcoe_destroy_work); /* configure fc_lport, e.g., em */ rc = fcoe_lport_config(lport); @@ -770,7 +777,6 @@ static struct fc_lport *fcoe_if_create(struct fcoe_interface *fcoe, goto out_lp_destroy; } - dev_hold(netdev); fcoe_interface_get(fcoe); return lport; @@ -1532,19 +1538,19 @@ static int fcoe_device_notification(struct notifier_block *notifier, struct fc_lport *lp = NULL; struct net_device *netdev = ptr; struct fcoe_interface *fcoe; + struct fcoe_port *port; struct fcoe_dev_stats *stats; u32 link_possible = 1; u32 mfs; int rc = NOTIFY_OK; - read_lock(&fcoe_hostlist_lock); + write_lock(&fcoe_hostlist_lock); list_for_each_entry(fcoe, &fcoe_hostlist, list) { if (fcoe->netdev == netdev) { lp = fcoe->ctlr.lp; break; } } - read_unlock(&fcoe_hostlist_lock); if (lp == NULL) { rc = NOTIFY_DONE; goto out; @@ -1566,6 +1572,12 @@ static int fcoe_device_notification(struct notifier_block *notifier, break; case NETDEV_REGISTER: break; + case NETDEV_UNREGISTER: + list_del(&fcoe->list); + port = lport_priv(fcoe->ctlr.lp); + schedule_work(&port->destroy_work); + goto out; + break; default: FCOE_NETDEV_DBG(netdev, "Unknown event %ld " "from netdev netlink\n", event); @@ -1578,6 +1590,7 @@ static int fcoe_device_notification(struct notifier_block *notifier, fcoe_clean_pending_queue(lp); } out: + write_unlock(&fcoe_hostlist_lock); return rc; } @@ -1603,75 +1616,6 @@ static struct net_device *fcoe_if_to_netdev(const char *buffer) } /** - * fcoe_netdev_to_module_owner() - finds out the driver module of the netdev - * @netdev: the target netdev - * - * Returns: ptr to the struct module, NULL for failure - */ -static struct module * -fcoe_netdev_to_module_owner(const struct net_device *netdev) -{ - struct device *dev; - - if (!netdev) - return NULL; - - dev = netdev->dev.parent; - if (!dev) - return NULL; - - if (!dev->driver) - return NULL; - - return dev->driver->owner; -} - -/** - * fcoe_ethdrv_get() - Hold the Ethernet driver - * @netdev: the target netdev - * - * Holds the Ethernet driver module by try_module_get() for - * the corresponding netdev. - * - * Returns: 0 for success - */ -static int fcoe_ethdrv_get(const struct net_device *netdev) -{ - struct module *owner; - - owner = fcoe_netdev_to_module_owner(netdev); - if (owner) { - FCOE_NETDEV_DBG(netdev, "Hold driver module %s\n", - module_name(owner)); - return try_module_get(owner); - } - return -ENODEV; -} - -/** - * fcoe_ethdrv_put() - Release the Ethernet driver - * @netdev: the target netdev - * - * Releases the Ethernet driver module by module_put for - * the corresponding netdev. - * - * Returns: 0 for success - */ -static int fcoe_ethdrv_put(const struct net_device *netdev) -{ - struct module *owner; - - owner = fcoe_netdev_to_module_owner(netdev); - if (owner) { - FCOE_NETDEV_DBG(netdev, "Release driver module %s\n", - module_name(owner)); - module_put(owner); - return 0; - } - return -ENODEV; -} - -/** * fcoe_destroy() - handles the destroy from sysfs * @buffer: expected to be an eth if name * @kp: associated kernel param @@ -1680,10 +1624,8 @@ static int fcoe_ethdrv_put(const struct net_device *netdev) */ static int fcoe_destroy(const char *buffer, struct kernel_param *kp) { - struct net_device *netdev; struct fcoe_interface *fcoe; - struct fcoe_port *port; - struct fc_lport *lport; + struct net_device *netdev; int rc; mutex_lock(&fcoe_config_mutex); @@ -1704,26 +1646,33 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp) rc = -ENODEV; goto out_nodev; } - /* look for existing lport */ - lport = fcoe_hostlist_lookup(netdev); - if (!lport) { + + write_lock(&fcoe_hostlist_lock); + fcoe = fcoe_hostlist_lookup_port(netdev); + if (!fcoe) { + write_unlock(&fcoe_hostlist_lock); rc = -ENODEV; - goto out_putdev; + goto out_nodev; } - /* Remove the instance from fcoe's list */ - fcoe_hostlist_remove(lport); - port = lport_priv(lport); - fcoe = port->fcoe; - fcoe_if_destroy(lport); - fcoe_ethdrv_put(netdev); - rc = 0; -out_putdev: + list_del(&fcoe->list); + write_unlock(&fcoe_hostlist_lock); + fcoe_if_destroy(fcoe->ctlr.lp); dev_put(netdev); out_nodev: mutex_unlock(&fcoe_config_mutex); return rc; } +static void fcoe_destroy_work(struct work_struct *work) +{ + struct fcoe_port *port; + + port = container_of(work, struct fcoe_port, destroy_work); + mutex_lock(&fcoe_config_mutex); + fcoe_if_destroy(port->lport); + mutex_unlock(&fcoe_config_mutex); +} + /** * fcoe_create() - Handles the create call from sysfs * @buffer: expected to be an eth if name @@ -1756,12 +1705,12 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp) rc = -ENODEV; goto out_nodev; } + /* look for existing lport */ if (fcoe_hostlist_lookup(netdev)) { rc = -EEXIST; goto out_putdev; } - fcoe_ethdrv_get(netdev); fcoe = fcoe_interface_create(netdev); if (!fcoe) { @@ -1773,7 +1722,6 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp) if (IS_ERR(lport)) { printk(KERN_ERR "fcoe: Failed to create interface (%s)\n", netdev->name); - fcoe_ethdrv_put(netdev); rc = -EIO; goto out_free; } @@ -1790,11 +1738,12 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp) if (!fcoe_link_ok(lport)) fcoe_ctlr_link_up(&fcoe->ctlr); - dev_put(netdev); - mutex_unlock(&fcoe_config_mutex); - return 0; - + rc = 0; out_free: + /* + * Release from init in fcoe_interface_create(), on success lport + * should be holding a reference taken in fcoe_if_create(). + */ fcoe_interface_put(fcoe); out_putdev: dev_put(netdev); @@ -1974,25 +1923,6 @@ int fcoe_hostlist_add(const struct fc_lport *lport) } /** - * fcoe_hostlist_remove() - remove a lport from lports list - * @lp: ptr to the fc_lport to be removed - * - * Returns: 0 for success - */ -int fcoe_hostlist_remove(const struct fc_lport *lport) -{ - struct fcoe_interface *fcoe; - - write_lock_bh(&fcoe_hostlist_lock); - fcoe = fcoe_hostlist_lookup_port(fcoe_netdev(lport)); - BUG_ON(!fcoe); - list_del(&fcoe->list); - write_unlock_bh(&fcoe_hostlist_lock); - - return 0; -} - -/** * fcoe_init() - fcoe module loading initialization * * Returns 0 on success, negative on failure @@ -2046,6 +1976,7 @@ static void __exit fcoe_exit(void) { unsigned int cpu; struct fcoe_interface *fcoe, *tmp; + struct fcoe_port *port; mutex_lock(&fcoe_config_mutex); @@ -2055,7 +1986,8 @@ static void __exit fcoe_exit(void) write_lock_bh(&fcoe_hostlist_lock); list_for_each_entry_safe(fcoe, tmp, &fcoe_hostlist, list) { list_del(&fcoe->list); - fcoe_if_destroy(fcoe->ctlr.lp); + port = lport_priv(fcoe->ctlr.lp); + schedule_work(&port->destroy_work); } write_unlock_bh(&fcoe_hostlist_lock); @@ -2064,9 +1996,14 @@ static void __exit fcoe_exit(void) for_each_online_cpu(cpu) fcoe_percpu_thread_destroy(cpu); - /* detach from scsi transport */ - fcoe_if_exit(); - mutex_unlock(&fcoe_config_mutex); + + /* flush any asyncronous interface destroys, + * this should happen after the netdev notifier is unregistered */ + flush_scheduled_work(); + + /* detach from scsi transport + * must happen after all destroys are done, therefor after the flush */ + fcoe_if_exit(); } module_exit(fcoe_exit); diff --git a/drivers/scsi/fcoe/fcoe.h b/drivers/scsi/fcoe/fcoe.h index b9c9c7d..976321b 100644 --- a/drivers/scsi/fcoe/fcoe.h +++ b/drivers/scsi/fcoe/fcoe.h @@ -93,9 +93,11 @@ struct fcoe_interface { */ struct fcoe_port { struct fcoe_interface *fcoe; + struct fc_lport *lport; struct sk_buff_head fcoe_pending_queue; u8 fcoe_pending_queue_active; struct timer_list timer; /* queue timer */ + struct work_struct destroy_work; /* to prevent rtnl deadlocks */ }; #define fcoe_from_ctlr(fip) container_of(fip, struct fcoe_interface, ctlr) _______________________________________________ devel mailing list [email protected] http://www.open-fcoe.org/mailman/listinfo/devel
