From 7287fb9114096503eddfffb7b2ed691c809a6106 Mon Sep 17 00:00:00 2001 From: Robert Love Date: Fri, 28 Jan 2011 16:03:47 -0800 Subject: [PATCH] [SCSI] fcoe: Fix module reference count for vports vports are not grabbing module references but are releasing them. This causes the module reference count to decrement too many times and it wraps around past 0. The solution is to do a module_put() in fcoe_interface_release() so that the reference is only released when the fcoe_interface is released. There is a one-to-one relationship between the N_Port and the fcoe_interface, so the module reference will only be dropped when the N_Port is destroyed To create symetry in the code this patch moves the try_module_get() call into fcoe_interface_create(). This means that only the N_Port will grab a reference to the module when its corresponding fcoe_interface is created. This patch also makes it so that the fcoe_interface_create() routine encodes any error codes in the fcoe_interface pointer returned. This way its caller, fcoe_create(), can return an accurate error code. Signed-off-by: Robert Love Tested-by: Ross Brattain Signed-off-by: James Bottomley --- drivers/scsi/fcoe/fcoe.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 9f9600b67001..452b42169c48 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -356,10 +356,18 @@ static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev, struct fcoe_interface *fcoe; int err; + if (!try_module_get(THIS_MODULE)) { + FCOE_NETDEV_DBG(netdev, + "Could not get a reference to the module\n"); + fcoe = ERR_PTR(-EBUSY); + goto out; + } + fcoe = kzalloc(sizeof(*fcoe), GFP_KERNEL); if (!fcoe) { FCOE_NETDEV_DBG(netdev, "Could not allocate fcoe structure\n"); - return NULL; + fcoe = ERR_PTR(-ENOMEM); + goto out_nomod; } dev_hold(netdev); @@ -378,9 +386,15 @@ static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev, fcoe_ctlr_destroy(&fcoe->ctlr); kfree(fcoe); dev_put(netdev); - return NULL; + fcoe = ERR_PTR(err); + goto out_nomod; } + goto out; + +out_nomod: + module_put(THIS_MODULE); +out: return fcoe; } @@ -442,6 +456,7 @@ static void fcoe_interface_release(struct kref *kref) fcoe_ctlr_destroy(&fcoe->ctlr); kfree(fcoe); dev_put(netdev); + module_put(THIS_MODULE); } /** @@ -886,7 +901,6 @@ static void fcoe_if_destroy(struct fc_lport *lport) /* Release the Scsi_Host */ scsi_host_put(lport->host); - module_put(THIS_MODULE); } /** @@ -2135,15 +2149,10 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp) */ if (THIS_MODULE->state != MODULE_STATE_LIVE) { rc = -ENODEV; - goto out_nomod; + goto out_nodev; } #endif - if (!try_module_get(THIS_MODULE)) { - rc = -EINVAL; - goto out_nomod; - } - netdev = fcoe_if_to_netdev(buffer); if (!netdev) { rc = -ENODEV; @@ -2157,8 +2166,8 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp) } fcoe = fcoe_interface_create(netdev, fip_mode); - if (!fcoe) { - rc = -ENOMEM; + if (IS_ERR(fcoe)) { + rc = PTR_ERR(fcoe); goto out_putdev; } @@ -2198,8 +2207,6 @@ out_free: out_putdev: dev_put(netdev); out_nodev: - module_put(THIS_MODULE); -out_nomod: rtnl_unlock(); mutex_unlock(&fcoe_config_mutex); return rc; -- 2.34.1