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>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4771de2..a8ad8f8 100644 (file)
--- 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);