rbd: simplify error handling in rbd_add()

If a couple pointers are initialized to NULL then a single
"out_nomem" label can be used for all of the memory allocation
failure cases in rbd_add().

Also, get rid of the "irc" local variable there.  There is no
real need for "rc" to be type ssize_t, and it can be used in
the spot "irc" was.

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 606d59a..8ac26ab 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2224,28 +2224,24 @@ static ssize_t rbd_add(struct bus_type *bus,
                       const char *buf,
                       size_t count)
 {
-       struct ceph_osd_client *osdc;
        struct rbd_device *rbd_dev;
-       ssize_t rc = -ENOMEM;
-       int irc;
-       char *mon_dev_name;
-       char *options;
+       char *mon_dev_name = NULL;
+       char *options = NULL;
+       struct ceph_osd_client *osdc;
+       int rc = -ENOMEM;
 
        if (!try_module_get(THIS_MODULE))
                return -ENODEV;
 
+       rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
+       if (!rbd_dev)
+               goto err_nomem;
        mon_dev_name = kmalloc(count, GFP_KERNEL);
        if (!mon_dev_name)
-               goto err_out_mod;
-
+               goto err_nomem;
        options = kmalloc(count, GFP_KERNEL);
        if (!options)
-               goto err_mon_dev;
-
-       /* new rbd_device object */
-       rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
-       if (!rbd_dev)
-               goto err_out_opt;
+               goto err_nomem;
 
        /* static rbd_device initialization */
        spin_lock_init(&rbd_dev->lock);
@@ -2294,12 +2290,10 @@ static ssize_t rbd_add(struct bus_type *bus,
        rbd_dev->poolid = rc;
 
        /* register our block device */
-       irc = register_blkdev(0, rbd_dev->name);
-       if (irc < 0) {
-               rc = irc;
+       rc = register_blkdev(0, rbd_dev->name);
+       if (rc < 0)
                goto err_out_client;
-       }
-       rbd_dev->major = irc;
+       rbd_dev->major = rc;
 
        rc = rbd_bus_add_dev(rbd_dev);
        if (rc)
@@ -2332,15 +2326,15 @@ err_out_client:
        rbd_put_client(rbd_dev);
 err_put_id:
        rbd_id_put(rbd_dev);
-       kfree(rbd_dev);
-err_out_opt:
+err_nomem:
        kfree(options);
-err_mon_dev:
        kfree(mon_dev_name);
-err_out_mod:
+       kfree(rbd_dev);
+
        dout("Error adding device %s\n", buf);
        module_put(THIS_MODULE);
-       return rc;
+
+       return (ssize_t) rc;
 }
 
 static struct rbd_device *__rbd_get_dev(unsigned long id)