From: Vaios Papadimitriou <vaios.papadimitriou@emulex.com>
Date: Tue, 8 May 2012 22:01:25 +0000 (-0500)
Subject: Fix management communication issues by creating character device to take a reference... 
X-Git-Tag: v2.6.39-400.9.0~423^2~123^2~16
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=20803ce4a7305e8e4b0ce20368974f23e6f29099;p=users%2Fjedix%2Flinux-maple.git

Fix management communication issues by creating character device to take a reference on the driver (CR 126082)

The management userspace applications have no way to take a lock on the driver
to prevent it from unloading. To remedy this a character device is created that
will up the reference count on lpfc by one when it is opened and decrement it by
one when it is closed.

commit id: 3ef6d24cd9f473518dd7941e86cc2a5f8992eed0

Signed-off-by: Maxim Uvarov <maxim.uvarov@oracle.com>
---

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index b1af6624b94f..f5a04ea880ee 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -31,6 +31,7 @@
 #include <linux/aer.h>
 #include <linux/slab.h>
 #include <linux/firmware.h>
+#include <linux/miscdevice.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_device.h>
@@ -10048,6 +10049,36 @@ lpfc_io_resume(struct pci_dev *pdev)
 	return;
 }
 
+/**
+ * lpfc_mgmt_open - method called when 'lpfcmgmt' is opened from userspace
+ * @inode: pointer to the inode representing the lpfcmgmt device
+ * @filep: pointer to the file representing the open lpfcmgmt device
+ *
+ * This routine puts a reference count on the lpfc module whenever the
+ * character device is opened
+ **/
+static int
+lpfc_mgmt_open(struct inode *inode, struct file *filep)
+{
+	try_module_get(THIS_MODULE);
+	return 0;
+}
+
+/**
+ * lpfc_mgmt_release - method called when 'lpfcmgmt' is closed in userspace
+ * @inode: pointer to the inode representing the lpfcmgmt device
+ * @filep: pointer to the file representing the open lpfcmgmt device
+ *
+ * This routine removes a reference count from the lpfc module when the
+ * character device is closed
+ **/
+static int
+lpfc_mgmt_release(struct inode *inode, struct file *filep)
+{
+	module_put(THIS_MODULE);
+	return 0;
+}
+
 static struct pci_device_id lpfc_id_table[] = {
 	{PCI_VENDOR_ID_EMULEX, PCI_DEVICE_ID_VIPER,
 		PCI_ANY_ID, PCI_ANY_ID, },
@@ -10160,6 +10191,17 @@ static struct pci_driver lpfc_driver = {
 	.err_handler    = &lpfc_err_handler,
 };
 
+static const struct file_operations lpfc_mgmt_fop = {
+	.open = lpfc_mgmt_open,
+	.release = lpfc_mgmt_release,
+};
+
+static struct miscdevice lpfc_mgmt_dev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "lpfcmgmt",
+	.fops = &lpfc_mgmt_fop,
+};
+
 /**
  * lpfc_init - lpfc module initialization routine
  *
@@ -10180,6 +10222,11 @@ lpfc_init(void)
 	printk(LPFC_MODULE_DESC "\n");
 	printk(LPFC_COPYRIGHT "\n");
 
+	error = misc_register(&lpfc_mgmt_dev);
+	if (error)
+		printk(KERN_ERR "Could not register lpfcmgmt device, "
+			"misc_register returned with status %d", error);
+
 	if (lpfc_enable_npiv) {
 		lpfc_transport_functions.vport_create = lpfc_vport_create;
 		lpfc_transport_functions.vport_delete = lpfc_vport_delete;
@@ -10216,6 +10263,7 @@ lpfc_init(void)
 static void __exit
 lpfc_exit(void)
 {
+	misc_deregister(&lpfc_mgmt_dev);
 	pci_unregister_driver(&lpfc_driver);
 	fc_release_transport(lpfc_transport_template);
 	if (lpfc_enable_npiv)