Commit 37c1209d authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Eric Van Hensbergen
Browse files

net/9p: Remove MAX_9P_CHAN limit 



Use a list to track the channel instead of statically
allocated array

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent f75580c4

include/linux/virtio_9p.h

+0 −3
Original line number Diff line number Diff line
@@ -5,7 +5,4 @@ 
#include <linux/virtio_ids.h>

#include <linux/virtio_config.h>



/* Maximum number of virtio channels per partition (1 for now) */

#define MAX_9P_CHAN	10



#endif /* _LINUX_VIRTIO_9P_H */

net/9p/trans_virtio.c

+27 −43
Original line number Diff line number Diff line
@@ -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 int chan_index; 
 *

 */



static struct virtio_chan {

	bool initialized;

struct virtio_chan {

	bool inuse;



	spinlock_t lock;
@@ -80,7 +77,11 @@ static struct virtio_chan { 


	/* 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_request(struct p9_client *client, struct p9_req_t *req) 
 * 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 @@ static int p9_virtio_probe(struct virtio_device *vdev) 
{

	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 @@ static int p9_virtio_probe(struct virtio_device *vdev) 
	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 @@ static int p9_virtio_probe(struct virtio_device *vdev) 
 * 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 @@ static void p9_virtio_remove(struct virtio_device *vdev) 
	struct virtio_chan *chan = vdev->priv;



	BUG_ON(chan->inuse);



	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 @@ static struct p9_trans_module p9_virtio_trans = { 
/* 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);