NVMe: Namespace removal simplifications

This liberates namespace removal from the device, allowing gendisk
references to be closed independent of the nvme controller reference
count.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index b02ae3d759d7098e44b545b1e7c4cac4494bb326..904b54fcbbcd7ae1517253ed7a6556f4d7f96ec0 100644 (file)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1943,6 +1943,7 @@ static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
 #define nvme_compat_ioctl      NULL
 #endif
 
+static void nvme_free_dev(struct kref *kref);
 static void nvme_free_ns(struct kref *kref)
 {
        struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
@@ -1951,6 +1952,7 @@ static void nvme_free_ns(struct kref *kref)
        ns->disk->private_data = NULL;
        spin_unlock(&dev_list_lock);
 
+       kref_put(&ns->dev->kref, nvme_free_dev);
        put_disk(ns->disk);
        kfree(ns);
 }
@@ -1966,22 +1968,14 @@ static int nvme_open(struct block_device *bdev, fmode_t mode)
                ret = -ENXIO;
        else if (!kref_get_unless_zero(&ns->kref))
                ret = -ENXIO;
-       else if (!kref_get_unless_zero(&ns->dev->kref)) {
-               kref_put(&ns->kref, nvme_free_ns);
-               ret = -ENXIO;
-       }
        spin_unlock(&dev_list_lock);
 
        return ret;
 }
 
-static void nvme_free_dev(struct kref *kref);
 static void nvme_release(struct gendisk *disk, fmode_t mode)
 {
        struct nvme_ns *ns = disk->private_data;
-       struct nvme_dev *dev = ns->dev;
-
-       kref_put(&dev->kref, nvme_free_dev);
        kref_put(&ns->kref, nvme_free_ns);
 }
 
@@ -2179,6 +2173,7 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid)
        if (nvme_revalidate_disk(ns->disk))
                goto out_free_disk;
 
+       kref_get(&dev->kref);
        add_disk(ns->disk);
        if (ns->ms) {
                struct block_device *bd = bdget_disk(ns->disk, 0);
@@ -2374,12 +2369,6 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
        return result;
 }
 
-static void nvme_free_namespace(struct nvme_ns *ns)
-{
-       list_del(&ns->list);
-       kref_put(&ns->kref, nvme_free_ns);
-}
-
 static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
 {
        struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
@@ -2421,7 +2410,9 @@ static void nvme_ns_remove(struct nvme_ns *ns)
        if (kill || !blk_queue_dying(ns->queue)) {
                blk_mq_abort_requeue_list(ns->queue);
                blk_cleanup_queue(ns->queue);
-        }
+       }
+       list_del_init(&ns->list);
+       kref_put(&ns->kref, nvme_free_ns);
 }
 
 static void nvme_scan_namespaces(struct nvme_dev *dev, unsigned nn)
@@ -2432,18 +2423,14 @@ static void nvme_scan_namespaces(struct nvme_dev *dev, unsigned nn)
        for (i = 1; i <= nn; i++) {
                ns = nvme_find_ns(dev, i);
                if (ns) {
-                       if (revalidate_disk(ns->disk)) {
+                       if (revalidate_disk(ns->disk))
                                nvme_ns_remove(ns);
-                               nvme_free_namespace(ns);
-                       }
                } else
                        nvme_alloc_ns(dev, i);
        }
        list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
-               if (ns->ns_id > nn) {
+               if (ns->ns_id > nn)
                        nvme_ns_remove(ns);
-                       nvme_free_namespace(ns);
-               }
        }
        list_sort(NULL, &dev->namespaces, ns_cmp);
 }
@@ -2833,9 +2820,9 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
 
 static void nvme_dev_remove(struct nvme_dev *dev)
 {
-       struct nvme_ns *ns;
+       struct nvme_ns *ns, *next;
 
-       list_for_each_entry(ns, &dev->namespaces, list)
+       list_for_each_entry_safe(ns, next, &dev->namespaces, list)
                nvme_ns_remove(ns);
 }
 
@@ -2891,21 +2878,12 @@ static void nvme_release_instance(struct nvme_dev *dev)
        spin_unlock(&dev_list_lock);
 }
 
-static void nvme_free_namespaces(struct nvme_dev *dev)
-{
-       struct nvme_ns *ns, *next;
-
-       list_for_each_entry_safe(ns, next, &dev->namespaces, list)
-               nvme_free_namespace(ns);
-}
-
 static void nvme_free_dev(struct kref *kref)
 {
        struct nvme_dev *dev = container_of(kref, struct nvme_dev, kref);
 
        put_device(dev->dev);
        put_device(dev->device);
-       nvme_free_namespaces(dev);
        nvme_release_instance(dev);
        if (dev->tagset.tags)
                blk_mq_free_tag_set(&dev->tagset);