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>

1 files changed, 17 insertions, 23 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 606d59aece2b..8ac26ab09aa0 100644
--- 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)