net/9p: Remove MAX_9P_CHAN limit
Use a list to track the channel instead of statically
allocated array
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index df924e5..05918d3 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -49,8 +49,6 @@
/* a single mutex to manage channel initialization and attachment */
static DEFINE_MUTEX(virtio_9p_lock);
-/* global which tracks highest initialized channel */
-static int chan_index;
/**
* struct virtio_chan - per-instance transport information
@@ -68,8 +66,7 @@
*
*/
-static struct virtio_chan {
- bool initialized;
+struct virtio_chan {
bool inuse;
spinlock_t lock;
@@ -80,7 +77,11 @@
/* Scatterlist: can be too big for stack. */
struct scatterlist sg[VIRTQUEUE_NUM];
-} channels[MAX_9P_CHAN];
+
+ struct list_head chan_list;
+};
+
+static struct list_head virtio_chan_list;
/* How many bytes left in this page. */
static unsigned int rest_of_page(void *data)
@@ -217,9 +218,7 @@
* p9_virtio_probe - probe for existence of 9P virtio channels
* @vdev: virtio device to probe
*
- * This probes for existing virtio channels. At present only
- * a single channel is in use, so in the future more work may need
- * to be done here.
+ * This probes for existing virtio channels.
*
*/
@@ -227,16 +226,10 @@
{
int err;
struct virtio_chan *chan;
- int index;
- mutex_lock(&virtio_9p_lock);
- index = chan_index++;
- chan = &channels[index];
- mutex_unlock(&virtio_9p_lock);
-
- if (chan_index > MAX_9P_CHAN) {
- printk(KERN_ERR "9p: virtio: Maximum channels exceeded\n");
- BUG();
+ chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
+ if (!chan) {
+ printk(KERN_ERR "9p: Failed to allocate virtio 9P channel\n");
err = -ENOMEM;
goto fail;
}
@@ -255,15 +248,15 @@
sg_init_table(chan->sg, VIRTQUEUE_NUM);
chan->inuse = false;
- chan->initialized = true;
+ mutex_lock(&virtio_9p_lock);
+ list_add_tail(&chan->chan_list, &virtio_chan_list);
+ mutex_unlock(&virtio_9p_lock);
return 0;
out_free_vq:
vdev->config->del_vqs(vdev);
+ kfree(chan);
fail:
- mutex_lock(&virtio_9p_lock);
- chan_index--;
- mutex_unlock(&virtio_9p_lock);
return err;
}
@@ -280,35 +273,27 @@
* We use a simple reference count mechanism to ensure that only a single
* mount has a channel open at a time.
*
- * Bugs: doesn't allow identification of a specific channel
- * to allocate, channels are allocated sequentially. This was
- * a pragmatic decision to get things rolling, but ideally some
- * way of identifying the channel to attach to would be nice
- * if we are going to support multiple channels.
- *
*/
static int
p9_virtio_create(struct p9_client *client, const char *devname, char *args)
{
- struct virtio_chan *chan = channels;
- int index = 0;
+ struct virtio_chan *chan;
+ int found = 0;
mutex_lock(&virtio_9p_lock);
- while (index < MAX_9P_CHAN) {
- if (chan->initialized &&
- !strcmp(devname, dev_name(&chan->vdev->dev))) {
+ list_for_each_entry(chan, &virtio_chan_list, chan_list) {
+ if (!strcmp(devname, dev_name(&chan->vdev->dev))) {
if (!chan->inuse) {
chan->inuse = true;
+ found = 1;
break;
}
}
- index++;
- chan = &channels[index];
}
mutex_unlock(&virtio_9p_lock);
- if (index >= MAX_9P_CHAN) {
+ if (!found) {
printk(KERN_ERR "9p: no channels available\n");
return -ENODEV;
}
@@ -331,11 +316,13 @@
struct virtio_chan *chan = vdev->priv;
BUG_ON(chan->inuse);
+ vdev->config->del_vqs(vdev);
- if (chan->initialized) {
- vdev->config->del_vqs(vdev);
- chan->initialized = false;
- }
+ mutex_lock(&virtio_9p_lock);
+ list_del(&chan->chan_list);
+ mutex_unlock(&virtio_9p_lock);
+ kfree(chan);
+
}
static struct virtio_device_id id_table[] = {
@@ -366,10 +353,7 @@
/* The standard init function */
static int __init p9_virtio_init(void)
{
- int count;
-
- for (count = 0; count < MAX_9P_CHAN; count++)
- channels[count].initialized = false;
+ INIT_LIST_HEAD(&virtio_chan_list);
v9fs_register_trans(&p9_virtio_trans);
return register_virtio_driver(&p9_virtio_drv);