block: cleanup __alloc_disk_node

Use early returns and goto-based unwinding to simplify the flow a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/genhd.c b/block/genhd.c
index 99c6464..055ce9c 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1729,45 +1729,48 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
        }
 
        disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
-       if (disk) {
-               disk->part0.dkstats = alloc_percpu(struct disk_stats);
-               if (!disk->part0.dkstats) {
-                       kfree(disk);
-                       return NULL;
-               }
-               init_rwsem(&disk->lookup_sem);
-               disk->node_id = node_id;
-               if (disk_expand_part_tbl(disk, 0)) {
-                       free_percpu(disk->part0.dkstats);
-                       kfree(disk);
-                       return NULL;
-               }
-               ptbl = rcu_dereference_protected(disk->part_tbl, 1);
-               rcu_assign_pointer(ptbl->part[0], &disk->part0);
+       if (!disk)
+               return NULL;
 
-               /*
-                * set_capacity() and get_capacity() currently don't use
-                * seqcounter to read/update the part0->nr_sects. Still init
-                * the counter as we can read the sectors in IO submission
-                * patch using seqence counters.
-                *
-                * TODO: Ideally set_capacity() and get_capacity() should be
-                * converted to make use of bd_mutex and sequence counters.
-                */
-               hd_sects_seq_init(&disk->part0);
-               if (hd_ref_init(&disk->part0)) {
-                       hd_free_part(&disk->part0);
-                       kfree(disk);
-                       return NULL;
-               }
+       disk->part0.dkstats = alloc_percpu(struct disk_stats);
+       if (!disk->part0.dkstats)
+               goto out_free_disk;
 
-               disk->minors = minors;
-               rand_initialize_disk(disk);
-               disk_to_dev(disk)->class = &block_class;
-               disk_to_dev(disk)->type = &disk_type;
-               device_initialize(disk_to_dev(disk));
+       init_rwsem(&disk->lookup_sem);
+       disk->node_id = node_id;
+       if (disk_expand_part_tbl(disk, 0)) {
+               free_percpu(disk->part0.dkstats);
+               goto out_free_disk;
        }
+
+       ptbl = rcu_dereference_protected(disk->part_tbl, 1);
+       rcu_assign_pointer(ptbl->part[0], &disk->part0);
+
+       /*
+        * set_capacity() and get_capacity() currently don't use
+        * seqcounter to read/update the part0->nr_sects. Still init
+        * the counter as we can read the sectors in IO submission
+        * patch using seqence counters.
+        *
+        * TODO: Ideally set_capacity() and get_capacity() should be
+        * converted to make use of bd_mutex and sequence counters.
+        */
+       hd_sects_seq_init(&disk->part0);
+       if (hd_ref_init(&disk->part0))
+               goto out_free_part0;
+
+       disk->minors = minors;
+       rand_initialize_disk(disk);
+       disk_to_dev(disk)->class = &block_class;
+       disk_to_dev(disk)->type = &disk_type;
+       device_initialize(disk_to_dev(disk));
        return disk;
+
+out_free_part0:
+       hd_free_part(&disk->part0);
+out_free_disk:
+       kfree(disk);
+       return NULL;
 }
 EXPORT_SYMBOL(__alloc_disk_node);