From 681dbd710779e8b8d5bae926f6b11f30df70638b Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Fri, 14 Aug 2009 15:49:46 +0000 Subject: cnic: Fix locking in start/stop calls. The slow path ulp_start and ulp_stop calls to the bnx2i driver are sleepable calls and therefore should not be protected using rcu_read_lock. Fix it by using mutex and setting a bit during these calls. cnic_unregister_device() will now wait for the bit to clear before completing the call. Signed-off-by: Michael Chan Reviewed-by: Benjamin Li Signed-off-by: David S. Miller --- drivers/net/cnic.c | 44 ++++++++++++++++++++++++++++---------------- drivers/net/cnic.h | 1 + 2 files changed, 29 insertions(+), 16 deletions(-) diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c index 2db81f0..4ff618a 100644 --- a/drivers/net/cnic.c +++ b/drivers/net/cnic.c @@ -466,6 +466,7 @@ EXPORT_SYMBOL(cnic_register_driver); static int cnic_unregister_device(struct cnic_dev *dev, int ulp_type) { struct cnic_local *cp = dev->cnic_priv; + int i = 0; if (ulp_type >= MAX_CNIC_ULP_TYPE) { printk(KERN_ERR PFX "cnic_unregister_device: Bad type %d\n", @@ -486,6 +487,15 @@ static int cnic_unregister_device(struct cnic_dev *dev, int ulp_type) synchronize_rcu(); + while (test_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[ulp_type]) && + i < 20) { + msleep(100); + i++; + } + if (test_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[ulp_type])) + printk(KERN_WARNING PFX "%s: Failed waiting for ULP up call" + " to complete.\n", dev->netdev->name); + return 0; } EXPORT_SYMBOL(cnic_unregister_driver); @@ -1076,18 +1086,23 @@ static void cnic_ulp_stop(struct cnic_dev *dev) if (cp->cnic_uinfo) cnic_send_nlmsg(cp, ISCSI_KEVENT_IF_DOWN, NULL); - rcu_read_lock(); for (if_type = 0; if_type < MAX_CNIC_ULP_TYPE; if_type++) { struct cnic_ulp_ops *ulp_ops; - ulp_ops = rcu_dereference(cp->ulp_ops[if_type]); - if (!ulp_ops) + mutex_lock(&cnic_lock); + ulp_ops = cp->ulp_ops[if_type]; + if (!ulp_ops) { + mutex_unlock(&cnic_lock); continue; + } + set_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]); + mutex_unlock(&cnic_lock); if (test_and_clear_bit(ULP_F_START, &cp->ulp_flags[if_type])) ulp_ops->cnic_stop(cp->ulp_handle[if_type]); + + clear_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]); } - rcu_read_unlock(); } static void cnic_ulp_start(struct cnic_dev *dev) @@ -1095,18 +1110,23 @@ static void cnic_ulp_start(struct cnic_dev *dev) struct cnic_local *cp = dev->cnic_priv; int if_type; - rcu_read_lock(); for (if_type = 0; if_type < MAX_CNIC_ULP_TYPE; if_type++) { struct cnic_ulp_ops *ulp_ops; - ulp_ops = rcu_dereference(cp->ulp_ops[if_type]); - if (!ulp_ops || !ulp_ops->cnic_start) + mutex_lock(&cnic_lock); + ulp_ops = cp->ulp_ops[if_type]; + if (!ulp_ops || !ulp_ops->cnic_start) { + mutex_unlock(&cnic_lock); continue; + } + set_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]); + mutex_unlock(&cnic_lock); if (!test_and_set_bit(ULP_F_START, &cp->ulp_flags[if_type])) ulp_ops->cnic_start(cp->ulp_handle[if_type]); + + clear_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]); } - rcu_read_unlock(); } static int cnic_ctl(void *data, struct cnic_ctl_info *info) @@ -1116,22 +1136,18 @@ static int cnic_ctl(void *data, struct cnic_ctl_info *info) switch (info->cmd) { case CNIC_CTL_STOP_CMD: cnic_hold(dev); - mutex_lock(&cnic_lock); cnic_ulp_stop(dev); cnic_stop_hw(dev); - mutex_unlock(&cnic_lock); cnic_put(dev); break; case CNIC_CTL_START_CMD: cnic_hold(dev); - mutex_lock(&cnic_lock); if (!cnic_start_hw(dev)) cnic_ulp_start(dev); - mutex_unlock(&cnic_lock); cnic_put(dev); break; default: @@ -2667,10 +2683,8 @@ static int cnic_netdev_event(struct notifier_block *this, unsigned long event, cnic_put(dev); goto done; } - mutex_lock(&cnic_lock); if (!cnic_start_hw(dev)) cnic_ulp_start(dev); - mutex_unlock(&cnic_lock); } rcu_read_lock(); @@ -2689,10 +2703,8 @@ static int cnic_netdev_event(struct notifier_block *this, unsigned long event, rcu_read_unlock(); if (event == NETDEV_GOING_DOWN) { - mutex_lock(&cnic_lock); cnic_ulp_stop(dev); cnic_stop_hw(dev); - mutex_unlock(&cnic_lock); cnic_unregister_netdev(dev); } else if (event == NETDEV_UNREGISTER) { write_lock(&cnic_dev_lock); diff --git a/drivers/net/cnic.h b/drivers/net/cnic.h index 5192d4a..a94b302 100644 --- a/drivers/net/cnic.h +++ b/drivers/net/cnic.h @@ -176,6 +176,7 @@ struct cnic_local { unsigned long ulp_flags[MAX_CNIC_ULP_TYPE]; #define ULP_F_INIT 0 #define ULP_F_START 1 +#define ULP_F_CALL_PENDING 2 struct cnic_ulp_ops *ulp_ops[MAX_CNIC_ULP_TYPE]; /* protected by ulp_lock */ -- cgit v1.1