rbd: define rbd_dev_{create,destroy}() helpers

Encapsulate the creation/initialization and destruction of rbd
device structures.  The rbd_client and the rbd_spec structures
provided on creation hold references whose ownership is transferred
to the new rbd_device structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 41 insertions, 21 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4771de2fba8a..a8ad8f8370b6 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -504,7 +504,8 @@ static void rbd_client_release(struct kref *kref)
  */
 static void rbd_put_client(struct rbd_client *rbdc)
 {
-        kref_put(&rbdc->kref, rbd_client_release);
+        if (rbdc)
+                kref_put(&rbdc->kref, rbd_client_release);
 }
 
 /*
@@ -2166,6 +2167,34 @@ static void rbd_spec_free(struct kref *kref)
         kfree(spec);
 }
 
+struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
+                                struct rbd_spec *spec)
+{
+        struct rbd_device *rbd_dev;
+
+        rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
+        if (!rbd_dev)
+                return NULL;
+
+        spin_lock_init(&rbd_dev->lock);
+        INIT_LIST_HEAD(&rbd_dev->node);
+        INIT_LIST_HEAD(&rbd_dev->snaps);
+        init_rwsem(&rbd_dev->header_rwsem);
+
+        rbd_dev->spec = spec;
+        rbd_dev->rbd_client = rbdc;
+
+        return rbd_dev;
+}
+
+static void rbd_dev_destroy(struct rbd_device *rbd_dev)
+{
+        kfree(rbd_dev->header_name);
+        rbd_put_client(rbd_dev->rbd_client);
+        rbd_spec_put(rbd_dev->spec);
+        kfree(rbd_dev);
+}
+
 static bool rbd_snap_registered(struct rbd_snap *snap)
 {
         bool ret = snap->dev.type == &rbd_snap_device_type;
@@ -3242,7 +3271,7 @@ static ssize_t rbd_add(struct bus_type *bus,
                 rc = PTR_ERR(rbdc);
                 goto err_out_args;
         }
-        ceph_opts = NULL;       /* ceph_opts now owned by rbd_dev client */
+        ceph_opts = NULL;       /* rbd_dev client now owns this */
 
         /* pick the pool */
         osdc = &rbdc->client->osdc;
@@ -3251,22 +3280,19 @@ static ssize_t rbd_add(struct bus_type *bus,
                 goto err_out_client;
         spec->pool_id = (u64) rc;
 
-        rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
+        rbd_dev = rbd_dev_create(rbdc, spec);
         if (!rbd_dev)
                 goto err_out_client;
-
-        spin_lock_init(&rbd_dev->lock);
-        INIT_LIST_HEAD(&rbd_dev->node);
-        INIT_LIST_HEAD(&rbd_dev->snaps);
-        init_rwsem(&rbd_dev->header_rwsem);
-        rbd_dev->rbd_client = rbdc;
-        rbd_dev->spec = spec;
+        rbdc = NULL;            /* rbd_dev now owns this */
+        spec = NULL;            /* rbd_dev now owns this */
 
         rbd_dev->mapping.read_only = rbd_opts->read_only;
+        kfree(rbd_opts);
+        rbd_opts = NULL;        /* done with this */
 
         rc = rbd_dev_probe(rbd_dev);
         if (rc < 0)
-                goto err_out_mem;
+                goto err_out_rbd_dev;
 
         /* no need to lock here, as rbd_dev is not registered yet */
         rc = rbd_dev_snaps_update(rbd_dev);
@@ -3317,8 +3343,6 @@ static ssize_t rbd_add(struct bus_type *bus,
         if (rc)
                 goto err_out_bus;
 
-        kfree(rbd_opts);
-
         /* Everything's ready.  Announce the disk to the world. */
 
         add_disk(rbd_dev->disk);
@@ -3332,7 +3356,6 @@ err_out_bus:
         /* this will also clean up rest of rbd_dev stuff */
 
         rbd_bus_del_dev(rbd_dev);
-        kfree(rbd_opts);
 
         return rc;
 
@@ -3346,9 +3369,8 @@ err_out_snaps:
         rbd_remove_all_snaps(rbd_dev);
 err_out_probe:
         rbd_header_free(&rbd_dev->header);
-        kfree(rbd_dev->header_name);
-err_out_mem:
-        kfree(rbd_dev);
+err_out_rbd_dev:
+        rbd_dev_destroy(rbd_dev);
 err_out_client:
         rbd_put_client(rbdc);
 err_out_args:
@@ -3394,7 +3416,6 @@ static void rbd_dev_release(struct device *dev)
         if (rbd_dev->watch_event)
                 rbd_req_sync_unwatch(rbd_dev);
 
-        rbd_put_client(rbd_dev->rbd_client);
 
         /* clean up and free blkdev */
         rbd_free_disk(rbd_dev);
@@ -3404,10 +3425,9 @@ static void rbd_dev_release(struct device *dev)
         rbd_header_free(&rbd_dev->header);
 
         /* done with the id, and with the rbd_dev */
-        kfree(rbd_dev->header_name);
         rbd_dev_id_put(rbd_dev);
-        rbd_spec_put(rbd_dev->spec);
-        kfree(rbd_dev);
+        rbd_assert(rbd_dev->rbd_client != NULL);
+        rbd_dev_destroy(rbd_dev);
 
         /* release module ref */
         module_put(THIS_MODULE);