[PATCH 55/62] firewire: Remove call to idr_preload

[Matthew Wilcox]

From: Matthew Wilcox <mawil...@microsoft.com>

core-cdev uses a spinlock to protect several elements, including the IDR.
Rather than reusing the IDR's spinlock for all of this, preallocate the
necessary memory by allocating a NULL pointer and then replace it with
the resource pointer once we have the spinlock.

Signed-off-by: Matthew Wilcox <mawil...@microsoft.com>
---
 drivers/firewire/core-cdev.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index a301fcf46e88..52c22c39744e 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -486,28 +486,24 @@ static int ioctl_get_info(struct client *client, union 
ioctl_arg *arg)
 static int add_client_resource(struct client *client,
                               struct client_resource *resource, gfp_t gfp_mask)
 {
-       bool preload = gfpflags_allow_blocking(gfp_mask);
        unsigned long flags;
        int ret;
 
-       if (preload)
-               idr_preload(gfp_mask);
-       spin_lock_irqsave(&client->lock, flags);
+       ret = idr_alloc(&client->resource_idr, NULL, 0, 0, gfp_mask);
+       if (ret < 0)
+               return ret;
 
-       if (client->in_shutdown)
+       spin_lock_irqsave(&client->lock, flags);
+       if (client->in_shutdown) {
+               idr_remove(&client->resource_idr, ret);
                ret = -ECANCELED;
-       else
-               ret = idr_alloc(&client->resource_idr, resource, 0, 0,
-                               GFP_NOWAIT);
-       if (ret >= 0) {
+       } else {
+               idr_replace(&client->resource_idr, resource, ret);
                resource->handle = ret;
                client_get(client);
                schedule_if_iso_resource(resource);
        }
-
        spin_unlock_irqrestore(&client->lock, flags);
-       if (preload)
-               idr_preload_end();
 
        return ret < 0 ? ret : 0;
 }
-- 
2.15.0