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

Matthew Wilcox
2017-11-22T21:11:06Z

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 <mawilcox@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