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 <mawilcox@microsoft.com>

9 files changed, 15 insertions, 29 deletions

diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c
index cb28579e8a94..d879f3bca107 100644
--- a/drivers/atm/nicstar.c
+++ b/drivers/atm/nicstar.c
@@ -1980,13 +1980,12 @@ static void dequeue_rx(ns_dev * card, ns_rsqe * rsqe)
         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
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 83482721bc01..6bb3b80e7e51 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2915,11 +2915,9 @@ out_idr_remove_vol:
         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);
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index aee149bdf4c0..a301fcf46e88 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1307,8 +1307,7 @@ static void iso_resource_work(struct work_struct *work)
          */
         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;
         }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
index c02db01f6583..0218cea6be4d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
@@ -70,10 +70,10 @@ static void amdgpu_bo_list_destroy(struct amdgpu_fpriv *fpriv, int id)
         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);
         }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index 400c66ba4c6b..cf0500671353 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -135,15 +135,11 @@ static int amdgpu_ctx_free(struct amdgpu_fpriv *fpriv, uint32_t id)
         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,
diff --git a/drivers/net/wireless/marvell/mwifiex/txrx.c b/drivers/net/wireless/marvell/mwifiex/txrx.c
index abdd0cf710bf..fac28bd8fbee 100644
--- a/drivers/net/wireless/marvell/mwifiex/txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/txrx.c
@@ -346,9 +346,7 @@ void mwifiex_parse_tx_status_event(struct mwifiex_private *priv,
                 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) {
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 8041710b6972..18f0ec2e1f9c 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -642,9 +642,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
                 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) {
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 2027c7aba50d..bf70b3ef0a07 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -88,9 +88,9 @@ void *idr_get_next(struct idr *, int *nextid);
 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)
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index ddf71c648cab..43dd3316d8a4 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -462,9 +462,7 @@ static void ieee80211_report_ack_skb(struct ieee80211_local *local,
         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)