V4L/DVB (4373): Correctly handle sysfs error leg file removal in pvrusb2

Take note of which sysfs files / groups that the pvrusb2 successfully
creates and only delete those specific items when tearing things
down.  (Previously we just blindly tore everything down every time.)
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pvrusb2/pvrusb2-sysfs.c

@@ -44,12 +44,16 @@ struct pvr2_sysfs {
 	struct kobj_type ktype;
 	struct class_device_attribute attr_v4l_minor_number;
 	struct class_device_attribute attr_unit_number;
+	int v4l_minor_number_created_ok;
+	int unit_number_created_ok;
 };
 
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC
 struct pvr2_sysfs_debugifc {
 	struct class_device_attribute attr_debugcmd;
 	struct class_device_attribute attr_debuginfo;
+	int debugcmd_created_ok;
+	int debuginfo_created_ok;
 };
 #endif /* CONFIG_VIDEO_PVRUSB2_DEBUGIFC */
 
@@ -67,6 +71,7 @@ struct pvr2_sysfs_ctl_item {
 	struct pvr2_sysfs_ctl_item *item_next;
 	struct attribute *attr_gen[7];
 	struct attribute_group grp;
+	int created_ok;
 	char name[80];
 };
 
@@ -487,6 +492,7 @@ static void pvr2_sysfs_add_control(struct pvr2_sysfs *sfp,int ctl_id)
 	struct pvr2_sysfs_func_set *fp;
 	struct pvr2_ctrl *cptr;
 	unsigned int cnt,acnt;
+	int ret;
 
 	if ((ctl_id < 0) || (ctl_id >= (sizeof(funcs)/sizeof(funcs[0])))) {
 		return;
@@ -589,7 +595,13 @@ static void pvr2_sysfs_add_control(struct pvr2_sysfs *sfp,int ctl_id)
 	cip->grp.name = cip->name;
 	cip->grp.attrs = cip->attr_gen;
 
-	sysfs_create_group(&sfp->class_dev->kobj,&cip->grp);
+	ret = sysfs_create_group(&sfp->class_dev->kobj,&cip->grp);
+	if (ret) {
+		printk(KERN_WARNING "%s: sysfs_create_group error: %d\n",
+		       __FUNCTION__, ret);
+		return;
+	}
+	cip->created_ok = !0;
 }
 
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC
@@ -616,22 +628,33 @@ static void pvr2_sysfs_add_debugifc(struct pvr2_sysfs *sfp)
 	dip->attr_debuginfo.show = debuginfo_show;
 	sfp->debugifc = dip;
 	ret = class_device_create_file(sfp->class_dev,&dip->attr_debugcmd);
-	if (ret < 0)
+	if (ret < 0) {
 		printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
 		       __FUNCTION__, ret);
+	} else {
+		dip->debugcmd_created_ok = !0;
+	}
 	ret = class_device_create_file(sfp->class_dev,&dip->attr_debuginfo);
-	if (ret < 0)
+	if (ret < 0) {
 		printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
 		       __FUNCTION__, ret);
+	} else {
+		dip->debuginfo_created_ok = !0;
+	}
 }
 
 
 static void pvr2_sysfs_tear_down_debugifc(struct pvr2_sysfs *sfp)
 {
 	if (!sfp->debugifc) return;
-	class_device_remove_file(sfp->class_dev,
-				 &sfp->debugifc->attr_debuginfo);
-	class_device_remove_file(sfp->class_dev,&sfp->debugifc->attr_debugcmd);
+	if (sfp->debugifc->debuginfo_created_ok) {
+		class_device_remove_file(sfp->class_dev,
+					 &sfp->debugifc->attr_debuginfo);
+	}
+	if (sfp->debugifc->debugcmd_created_ok) {
+		class_device_remove_file(sfp->class_dev,
+					 &sfp->debugifc->attr_debugcmd);
+	}
 	kfree(sfp->debugifc);
 	sfp->debugifc = NULL;
 }
@@ -653,7 +676,9 @@ static void pvr2_sysfs_tear_down_controls(struct pvr2_sysfs *sfp)
 	struct pvr2_sysfs_ctl_item *cip1,*cip2;
 	for (cip1 = sfp->item_first; cip1; cip1 = cip2) {
 		cip2 = cip1->item_next;
-		sysfs_remove_group(&sfp->class_dev->kobj,&cip1->grp);
+		if (cip1->created_ok) {
+			sysfs_remove_group(&sfp->class_dev->kobj,&cip1->grp);
+		}
 		pvr2_sysfs_trace("Destroying pvr2_sysfs_ctl_item id=%p",cip1);
 		kfree(cip1);
 	}
@@ -683,8 +708,14 @@ static void class_dev_destroy(struct pvr2_sysfs *sfp)
 	pvr2_sysfs_tear_down_debugifc(sfp);
 #endif /* CONFIG_VIDEO_PVRUSB2_DEBUGIFC */
 	pvr2_sysfs_tear_down_controls(sfp);
-	class_device_remove_file(sfp->class_dev,&sfp->attr_v4l_minor_number);
-	class_device_remove_file(sfp->class_dev,&sfp->attr_unit_number);
+	if (sfp->v4l_minor_number_created_ok) {
+		class_device_remove_file(sfp->class_dev,
+					 &sfp->attr_v4l_minor_number);
+	}
+	if (sfp->unit_number_created_ok) {
+		class_device_remove_file(sfp->class_dev,
+					 &sfp->attr_unit_number);
+	}
 	pvr2_sysfs_trace("Destroying class_dev id=%p",sfp->class_dev);
 	sfp->class_dev->class_data = NULL;
 	class_device_unregister(sfp->class_dev);
@@ -756,10 +787,14 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 	sfp->attr_v4l_minor_number.attr.mode = S_IRUGO;
 	sfp->attr_v4l_minor_number.show = v4l_minor_number_show;
 	sfp->attr_v4l_minor_number.store = NULL;
-	ret = class_device_create_file(sfp->class_dev,&sfp->attr_v4l_minor_number);
-	if (ret < 0)
+	ret = class_device_create_file(sfp->class_dev,
+				       &sfp->attr_v4l_minor_number);
+	if (ret < 0) {
 		printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
 		       __FUNCTION__, ret);
+	} else {
+		sfp->v4l_minor_number_created_ok = !0;
+	}
 
 	sfp->attr_unit_number.attr.owner = THIS_MODULE;
 	sfp->attr_unit_number.attr.name = "unit_number";
@@ -767,9 +802,12 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 	sfp->attr_unit_number.show = unit_number_show;
 	sfp->attr_unit_number.store = NULL;
 	ret = class_device_create_file(sfp->class_dev,&sfp->attr_unit_number);
-	if (ret < 0)
+	if (ret < 0) {
 		printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
 		       __FUNCTION__, ret);
+	} else {
+		sfp->unit_number_created_ok = !0;
+	}
 
 	pvr2_sysfs_add_controls(sfp);
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC