Staging: ramzswap: Return proper error code on device create failure

Currently, we return 0 if create_device() fails and 1 otherwise.
Now, proper error code is returned from create_device() and the
same is propagated as module error code from ramzswap_init().

Also added some cleanups for ramzswap_init(), improving function
structure.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 2021ad6..3035add 100644 (file)
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1300,6 +1300,8 @@ static struct block_device_operations ramzswap_devops = {
 
 static int create_device(struct ramzswap *rzs, int device_id)
 {
+       int ret = 0;
+
        mutex_init(&rzs->lock);
        spin_lock_init(&rzs->stat64_lock);
        INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
@@ -1308,7 +1310,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
        if (!rzs->queue) {
                pr_err("Error allocating disk queue for device %d\n",
                        device_id);
-               return 0;
+               ret = -ENOMEM;
+               goto out;
        }
 
        blk_queue_make_request(rzs->queue, ramzswap_make_request);
@@ -1320,7 +1323,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
                blk_cleanup_queue(rzs->queue);
                pr_warning("Error allocating disk structure for device %d\n",
                        device_id);
-               return 0;
+               ret = -ENOMEM;
+               goto out;
        }
 
        rzs->disk->major = ramzswap_major;
@@ -1342,7 +1346,9 @@ static int create_device(struct ramzswap *rzs, int device_id)
        add_disk(rzs->disk);
 
        rzs->init_done = 0;
-       return 1;
+
+out:
+       return ret;
 }
 
 static void destroy_device(struct ramzswap *rzs)
@@ -1358,18 +1364,20 @@ static void destroy_device(struct ramzswap *rzs)
 
 static int __init ramzswap_init(void)
 {
-       int i, ret;
+       int ret, dev_id;
 
        if (num_devices > max_num_devices) {
                pr_warning("Invalid value for num_devices: %u\n",
                                num_devices);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
 
        ramzswap_major = register_blkdev(0, "ramzswap");
        if (ramzswap_major <= 0) {
                pr_warning("Unable to get major number\n");
-               return -EBUSY;
+               ret = -EBUSY;
+               goto out;
        }
 
        if (!num_devices) {
@@ -1380,21 +1388,25 @@ static int __init ramzswap_init(void)
        /* Allocate the device array and initialize each one */
        pr_info("Creating %u devices ...\n", num_devices);
        devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
-       if (!devices)
-               goto out;
+       if (!devices) {
+               ret = -ENOMEM;
+               goto unregister;
+       }
 
-       for (i = 0; i < num_devices; i++)
-               if (!create_device(&devices[i], i)) {
-                       ret = i;
+       for (dev_id = 0; dev_id < num_devices; dev_id++) {
+               ret = create_device(&devices[dev_id], dev_id);
+               if (ret)
                        goto free_devices;
-               }
+       }
+
        return 0;
+
 free_devices:
-       for (i = 0; i < ret; i++)
-               destroy_device(&devices[i]);
-out:
-       ret = -ENOMEM;
+       while (dev_id)
+               destroy_device(&devices[--dev_id]);
+unregister:
        unregister_blkdev(ramzswap_major, "ramzswap");
+out:
        return ret;
 }