diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/firewire/fw-cdev.c | 55 |
1 files changed, 46 insertions, 9 deletions
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c index ead5c7b..81362c1 100644 --- a/drivers/firewire/fw-cdev.c +++ b/drivers/firewire/fw-cdev.c @@ -20,6 +20,7 @@ #include <linux/module.h> #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/wait.h> #include <linux/errno.h> #include <linux/device.h> @@ -94,8 +95,27 @@ struct client { unsigned long vm_start; struct list_head link; + struct kref kref; }; +static inline void client_get(struct client *client) +{ + kref_get(&client->kref); +} + +static void client_release(struct kref *kref) +{ + struct client *client = container_of(kref, struct client, kref); + + fw_device_put(client->device); + kfree(client); +} + +static void client_put(struct client *client) +{ + kref_put(&client->kref, client_release); +} + static inline void __user *u64_to_uptr(__u64 value) { return (void __user *)(unsigned long)value; @@ -131,6 +151,7 @@ static int fw_device_op_open(struct inode *inode, struct file *file) idr_init(&client->resource_idr); INIT_LIST_HEAD(&client->event_list); init_waitqueue_head(&client->wait); + kref_init(&client->kref); file->private_data = client; @@ -326,6 +347,8 @@ static int add_client_resource(struct client *client, else ret = idr_get_new(&client->resource_idr, resource, &resource->handle); + if (ret >= 0) + client_get(client); spin_unlock_irqrestore(&client->lock, flags); if (ret == -EAGAIN) @@ -358,6 +381,8 @@ static int release_client_resource(struct client *client, u32 handle, else r->release(client, r); + client_put(client); + return 0; } @@ -385,11 +410,21 @@ static void complete_transaction(struct fw_card *card, int rcode, spin_lock_irqsave(&client->lock, flags); /* - * If called while in shutdown, the idr tree must be left untouched. - * The idr handle will be removed later. + * 1. If called while in shutdown, the idr tree must be left untouched. + * The idr handle will be removed and the client reference will be + * dropped later. + * 2. If the call chain was release_client_resource -> + * release_transaction -> complete_transaction (instead of a normal + * conclusion of the transaction), i.e. if this resource was already + * unregistered from the idr, the client reference will be dropped + * by release_client_resource and we must not drop it here. */ - if (!client->in_shutdown) + if (!client->in_shutdown && + idr_find(&client->resource_idr, response->resource.handle)) { idr_remove(&client->resource_idr, response->resource.handle); + /* Drop the idr's reference */ + client_put(client); + } spin_unlock_irqrestore(&client->lock, flags); r->type = FW_CDEV_EVENT_RESPONSE; @@ -408,6 +443,9 @@ static void complete_transaction(struct fw_card *card, int rcode, else queue_event(client, &response->event, r, sizeof(*r) + r->length, NULL, 0); + + /* Drop the transaction callback's reference */ + client_put(client); } static int ioctl_send_request(struct client *client, void *buffer) @@ -459,6 +497,9 @@ static int ioctl_send_request(struct client *client, void *buffer) if (ret < 0) goto failed; + /* Get a reference for the transaction callback */ + client_get(client); + fw_send_request(device->card, &response->transaction, request->tcode & 0x1f, device->node->node_id, @@ -1044,6 +1085,7 @@ static int shutdown_resource(int id, void *p, void *data) struct client *client = data; r->release(client, r); + client_put(client); return 0; } @@ -1076,12 +1118,7 @@ static int fw_device_op_release(struct inode *inode, struct file *file) list_for_each_entry_safe(e, next_e, &client->event_list, link) kfree(e); - /* - * FIXME: client should be reference-counted. It's extremely unlikely - * but there may still be transactions being completed at this point. - */ - fw_device_put(client->device); - kfree(client); + client_put(client); return 0; } |