idr: Return the deleted entry from idr_remove

It is a relatively common idiom (8 instances) to first look up an IDR
entry, and then remove it from the tree if it is found, possibly doing
further operations upon the entry afterwards. If we change idr_remove()
to return the removed object, all of these users can save themselves a
walk of the IDR tree.

Signed-off-by: Matthew Wilcox <[e-mail]>

drivers/atm/nicstar.c

···
 	card->lbfqc = ns_stat_lfbqc_get(stat);
 
 	id = le32_to_cpu(rsqe->buffer_handle);
-	skb = idr_find(&card->idr, id);
+	skb = idr_remove(&card->idr, id);
 	if (!skb) {
 		RXPRINTK(KERN_ERR
-			 "nicstar%d: idr_find() failed!\n", card->index);
+			 "nicstar%d: skb not found!\n", card->index);
 		return;
 	}
-	idr_remove(&card->idr, id);
 	dma_sync_single_for_cpu(&card->pcidev->dev,
 				NS_PRV_DMA(skb),
 				(NS_PRV_BUFTYPE(skb) == BUF_SM

drivers/block/drbd/drbd_main.c

···
 	idr_remove(&connection->peer_devices, vnr);
 out_idr_remove_from_resource:
 	for_each_connection(connection, resource) {
-		peer_device = idr_find(&connection->peer_devices, vnr);
-		if (peer_device) {
-			idr_remove(&connection->peer_devices, vnr);
+		peer_device = idr_remove(&connection->peer_devices, vnr);
+		if (peer_device)
 			kref_put(&connection->kref, drbd_destroy_connection);
-		}
 	}
 	for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
 		list_del(&peer_device->peer_devices);

drivers/firewire/core-cdev.c

···
 	 */
 	if (r->todo == ISO_RES_REALLOC && !success &&
 	    !client->in_shutdown &&
-	    idr_find(&client->resource_idr, r->resource.handle)) {
-		idr_remove(&client->resource_idr, r->resource.handle);
+	    idr_remove(&client->resource_idr, r->resource.handle)) {
 		client_put(client);
 		free = true;
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

···
 	struct amdgpu_bo_list *list;
 
 	mutex_lock(&fpriv->bo_list_lock);
-	list = idr_find(&fpriv->bo_list_handles, id);
+	list = idr_remove(&fpriv->bo_list_handles, id);
 	if (list) {
+		/* Another user may have a reference to this list still */
 		mutex_lock(&list->lock);
-		idr_remove(&fpriv->bo_list_handles, id);
 		mutex_unlock(&list->lock);
 		amdgpu_bo_list_free(list);
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c

···
 	struct amdgpu_ctx *ctx;
 
 	mutex_lock(&mgr->lock);
-	ctx = idr_find(&mgr->ctx_handles, id);
-	if (ctx) {
-		idr_remove(&mgr->ctx_handles, id);
+	ctx = idr_remove(&mgr->ctx_handles, id);
+	if (ctx)
 		kref_put(&ctx->refcount, amdgpu_ctx_do_release);
-		mutex_unlock(&mgr->lock);
-		return 0;
-	}
 	mutex_unlock(&mgr->lock);
-	return -EINVAL;
+	return ctx ? 0 : -EINVAL;
 }
 
 static int amdgpu_ctx_query(struct amdgpu_device *adev,

drivers/net/wireless/marvell/mwifiex/txrx.c

···
 		return;
 
 	spin_lock_irqsave(&priv->ack_status_lock, flags);
-	ack_skb = idr_find(&priv->ack_status_frames, tx_status->tx_token_id);
-	if (ack_skb)
-		idr_remove(&priv->ack_status_frames, tx_status->tx_token_id);
+	ack_skb = idr_remove(&priv->ack_status_frames, tx_status->tx_token_id);
 	spin_unlock_irqrestore(&priv->ack_status_lock, flags);
 
 	if (ack_skb) {

drivers/target/target_core_user.c

···
 		WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
 
 		spin_lock(&udev->commands_lock);
-		cmd = idr_find(&udev->commands, entry->hdr.cmd_id);
-		if (cmd)
-			idr_remove(&udev->commands, cmd->cmd_id);
+		cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
 		spin_unlock(&udev->commands_lock);
 
 		if (!cmd) {

include/linux/idr.h

···
 void *idr_replace(struct idr *, void *, int id);
 void idr_destroy(struct idr *);
 
-static inline void idr_remove(struct idr *idr, int id)
+static inline void *idr_remove(struct idr *idr, int id)
 {
-	radix_tree_delete(&idr->idr_rt, id);
+	return radix_tree_delete_item(&idr->idr_rt, id, NULL);
 }
 
 static inline void idr_init(struct idr *idr)

net/mac80211/status.c

···
 	unsigned long flags;
 
 	spin_lock_irqsave(&local->ack_status_lock, flags);
-	skb = idr_find(&local->ack_status_frames, info->ack_frame_id);
-	if (skb)
-		idr_remove(&local->ack_status_frames, info->ack_frame_id);
+	skb = idr_remove(&local->ack_status_frames, info->ack_frame_id);
 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
 
 	if (!skb)