[SCSI] SCSI osst: add error handling to module init, sysfs

- check all sysfs-related return codes, and propagate them back to callers

- properly unwind errors in osst_probe(), init_osst().  This fixes a
  leak that occured if scsi driver registration failed, and fixes an
  oops if sysfs creation returned an error.

(unrelated)
- kzalloc() cleanup in new_tape_buf()

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 9ecb323ebae8fa4bf78a5a67840798ae0f450f14..824fe080d1dc2b9d0b2e1a35b2e1a64464e615b9 100644 (file)
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -5206,12 +5206,12 @@ static struct osst_buffer * new_tape_buffer( int from_initialization, int need_d
                priority = GFP_KERNEL;
 
        i = sizeof(struct osst_buffer) + (osst_max_sg_segs - 1) * sizeof(struct scatterlist);
-       tb = (struct osst_buffer *)kmalloc(i, priority);
+       tb = kzalloc(i, priority);
        if (!tb) {
                printk(KERN_NOTICE "osst :I: Can't allocate new tape buffer.\n");
                return NULL;
        }
-       memset(tb, 0, i);
+
        tb->sg_segs = tb->orig_sg_segs = 0;
        tb->use_sg = max_sg;
        tb->in_use = 1;
@@ -5574,9 +5574,9 @@ static ssize_t osst_version_show(struct device_driver *ddd, char *buf)
 
 static DRIVER_ATTR(version, S_IRUGO, osst_version_show, NULL);
 
-static void osst_create_driverfs_files(struct device_driver *driverfs)
+static int osst_create_driverfs_files(struct device_driver *driverfs)
 {
-       driver_create_file(driverfs, &driver_attr_version);
+       return driver_create_file(driverfs, &driver_attr_version);
 }
 
 static void osst_remove_driverfs_files(struct device_driver *driverfs)
@@ -5662,50 +5662,70 @@ CLASS_DEVICE_ATTR(file_count, S_IRUGO, osst_filemark_cnt_show, NULL);
 
 static struct class *osst_sysfs_class;
 
-static int osst_sysfs_valid = 0;
-
-static void osst_sysfs_init(void)
+static int osst_sysfs_init(void)
 {
        osst_sysfs_class = class_create(THIS_MODULE, "onstream_tape");
-       if ( IS_ERR(osst_sysfs_class) )
-               printk(KERN_WARNING "osst :W: Unable to register sysfs class\n");
-       else
-               osst_sysfs_valid = 1;
+       if (IS_ERR(osst_sysfs_class)) {
+               printk(KERN_ERR "osst :W: Unable to register sysfs class\n");
+               return PTR_ERR(osst_sysfs_class);
+       }
+
+       return 0;
 }
 
-static void osst_sysfs_add(dev_t dev, struct device *device, struct osst_tape * STp, char * name)
+static void osst_sysfs_destroy(dev_t dev)
 {
-       struct class_device *osst_class_member;
+       class_device_destroy(osst_sysfs_class, dev);
+}
 
-       if (!osst_sysfs_valid) return;
+static int osst_sysfs_add(dev_t dev, struct device *device, struct osst_tape * STp, char * name)
+{
+       struct class_device *osst_class_member;
+       int err;
 
-       osst_class_member = class_device_create(osst_sysfs_class, NULL, dev, device, "%s", name);
+       osst_class_member = class_device_create(osst_sysfs_class, NULL, dev,
+                                               device, "%s", name);
        if (IS_ERR(osst_class_member)) {
                printk(KERN_WARNING "osst :W: Unable to add sysfs class member %s\n", name);
-               return;
+               return PTR_ERR(osst_class_member);
        }
+
        class_set_devdata(osst_class_member, STp);
-       class_device_create_file(osst_class_member, &class_device_attr_ADR_rev);
-       class_device_create_file(osst_class_member, &class_device_attr_media_version);
-       class_device_create_file(osst_class_member, &class_device_attr_capacity);
-       class_device_create_file(osst_class_member, &class_device_attr_BOT_frame);
-       class_device_create_file(osst_class_member, &class_device_attr_EOD_frame);
-       class_device_create_file(osst_class_member, &class_device_attr_file_count);
-}
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_ADR_rev);
+       if (err)
+               goto err_out;
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_media_version);
+       if (err)
+               goto err_out;
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_capacity);
+       if (err)
+               goto err_out;
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_BOT_frame);
+       if (err)
+               goto err_out;
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_EOD_frame);
+       if (err)
+               goto err_out;
+       err = class_device_create_file(osst_class_member,
+                                      &class_device_attr_file_count);
+       if (err)
+               goto err_out;
 
-static void osst_sysfs_destroy(dev_t dev)
-{
-       if (!osst_sysfs_valid) return; 
+       return 0;
 
-       class_device_destroy(osst_sysfs_class, dev);
+err_out:
+       osst_sysfs_destroy(dev);
+       return err;
 }
 
 static void osst_sysfs_cleanup(void)
 {
-       if (osst_sysfs_valid) {
-               class_destroy(osst_sysfs_class);
-               osst_sysfs_valid = 0;
-       }
+       class_destroy(osst_sysfs_class);
 }
 
 /*
@@ -5720,7 +5740,7 @@ static int osst_probe(struct device *dev)
        struct st_partstat * STps;
        struct osst_buffer * buffer;
        struct gendisk     * drive;
-       int                  i, dev_num;
+       int                  i, dev_num, err = -ENODEV;
 
        if (SDp->type != TYPE_TAPE || !osst_supports(SDp))
                return -ENODEV;
@@ -5848,13 +5868,20 @@ static int osst_probe(struct device *dev)
        init_MUTEX(&tpnt->lock);
        osst_nr_dev++;
        write_unlock(&os_scsi_tapes_lock);
+
        {
                char name[8];
+
                /*  Rewind entry  */
-               osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num), dev, tpnt, tape_name(tpnt));
+               err = osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num), dev, tpnt, tape_name(tpnt));
+               if (err)
+                       goto out_free_buffer;
+
                /*  No-rewind entry  */
                snprintf(name, 8, "%s%s", "n", tape_name(tpnt));
-               osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num + 128), dev, tpnt, name);
+               err = osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num + 128), dev, tpnt, name);
+               if (err)
+                       goto out_free_sysfs1;
        }
 
        sdev_printk(KERN_INFO, SDp,
@@ -5863,9 +5890,13 @@ static int osst_probe(struct device *dev)
 
        return 0;
 
+out_free_sysfs1:
+       osst_sysfs_destroy(MKDEV(OSST_MAJOR, dev_num));
+out_free_buffer:
+       kfree(buffer);
 out_put_disk:
         put_disk(drive);
-        return -ENODEV;
+        return err;
 };
 
 static int osst_remove(struct device *dev)
@@ -5902,19 +5933,39 @@ static int osst_remove(struct device *dev)
 
 static int __init init_osst(void) 
 {
+       int err;
+
        printk(KERN_INFO "osst :I: Tape driver with OnStream support version %s\nosst :I: %s\n", osst_version, cvsid);
 
        validate_options();
-       osst_sysfs_init();
 
-       if ((register_chrdev(OSST_MAJOR,"osst", &osst_fops) < 0) || scsi_register_driver(&osst_template.gendrv)) {
+       err = osst_sysfs_init();
+       if (err)
+               return err;
+
+       err = register_chrdev(OSST_MAJOR, "osst", &osst_fops);
+       if (err < 0) {
                printk(KERN_ERR "osst :E: Unable to register major %d for OnStream tapes\n", OSST_MAJOR);
-               osst_sysfs_cleanup();
-               return 1;
+               goto err_out;
        }
-       osst_create_driverfs_files(&osst_template.gendrv);
+
+       err = scsi_register_driver(&osst_template.gendrv);
+       if (err)
+               goto err_out_chrdev;
+
+       err = osst_create_driverfs_files(&osst_template.gendrv);
+       if (err)
+               goto err_out_scsidrv;
 
        return 0;
+
+err_out_scsidrv:
+       scsi_unregister_driver(&osst_template.gendrv);
+err_out_chrdev:
+       unregister_chrdev(OSST_MAJOR, "osst");
+err_out:
+       osst_sysfs_cleanup();
+       return err;
 }
 
 static void __exit exit_osst (void)