Add two new APIs to allocate and free a gendisk including the
request_queue for use with BIO based drivers.  This is to avoid
boilerplate code in drivers.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 block/genhd.c         | 35 +++++++++++++++++++++++++++++++++++
 include/linux/genhd.h | 22 ++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index e4974af3d729..6d4ce962866d 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1302,6 +1302,25 @@ struct gendisk *__alloc_disk_node(int minors, int 
node_id)
 }
 EXPORT_SYMBOL(__alloc_disk_node);
 
+struct gendisk *__blk_alloc_disk(int node)
+{
+       struct request_queue *q;
+       struct gendisk *disk;
+
+       q = blk_alloc_queue(node);
+       if (!q)
+               return NULL;
+
+       disk = __alloc_disk_node(0, node);
+       if (!disk) {
+               blk_cleanup_queue(q);
+               return NULL;
+       }
+       disk->queue = q;
+       return disk;
+}
+EXPORT_SYMBOL(__blk_alloc_disk);
+
 /**
  * put_disk - decrements the gendisk refcount
  * @disk: the struct gendisk to decrement the refcount for
@@ -1319,6 +1338,22 @@ void put_disk(struct gendisk *disk)
 }
 EXPORT_SYMBOL(put_disk);
 
+/**
+ * blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
+ * @disk: gendisk to shutdown
+ *
+ * Mark the queue hanging off @disk DYING, drain all pending requests, then 
mark
+ * the queue DEAD, destroy and put it and the gendisk structure.
+ *
+ * Context: can sleep
+ */
+void blk_cleanup_disk(struct gendisk *disk)
+{
+       blk_cleanup_queue(disk->queue);
+       put_disk(disk);
+}
+EXPORT_SYMBOL(blk_cleanup_disk);
+
 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
 {
        char event[] = "DISK_RO=1";
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index a5443f0b139d..03aa12730634 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -278,6 +278,28 @@ extern void put_disk(struct gendisk *disk);
 
 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 
+/**
+ * blk_alloc_disk - allocate a gendisk structure
+ * @node_id: numa node to allocate on
+ *
+ * Allocate and pre-initialize a gendisk structure for use with BIO based
+ * drivers.
+ *
+ * Context: can sleep
+ */
+#define blk_alloc_disk(node_id)                                                
\
+({                                                                     \
+       struct gendisk *__disk = __blk_alloc_disk(node_id);             \
+       static struct lock_class_key __key;                             \
+                                                                       \
+       if (__disk)                                                     \
+               lockdep_init_map(&__disk->lockdep_map,                  \
+                       "(bio completion)", &__key, 0);                 \
+       __disk;                                                         \
+})
+struct gendisk *__blk_alloc_disk(int node);
+void blk_cleanup_disk(struct gendisk *disk);
+
 int __register_blkdev(unsigned int major, const char *name,
                void (*probe)(dev_t devt));
 #define register_blkdev(major, name) \
-- 
2.30.2

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