#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
+#include <linux/slab.h>
#include <net/9p/9p.h>
#include <linux/parser.h>
#include <net/9p/client.h>
/* 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
* @initialized: whether the channel is initialized
* @inuse: whether the channel is in use
* @lock: protects multiple elements within this structure
+ * @client: client instance
* @vdev: virtio dev associated with this channel
* @vq: virtio queue associated with this channel
- * @tagpool: accounting for tag ids (and request slots)
- * @reqs: array of request slots
- * @max_tag: current number of request_slots allocated
* @sg: scatter gather list which is used to pack a request (protected?)
*
* We keep all per-channel information in a structure.
*
*/
-static struct virtio_chan {
- bool initialized;
+struct virtio_chan {
bool inuse;
spinlock_t lock;
/* Scatterlist: can be too big for stack. */
struct scatterlist sg[VIRTQUEUE_NUM];
-} channels[MAX_9P_CHAN];
+
+ int tag_len;
+ /*
+ * tag name to identify a mount Non-null terminated
+ */
+ char *tag;
+
+ 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)
/**
* p9_virtio_close - reclaim resources of a channel
- * @trans: transport state
+ * @client: client instance
*
* This reclaims a channel by freeing its resources and
* reseting its inuse flag.
struct virtio_chan *chan = client->trans;
mutex_lock(&virtio_9p_lock);
- chan->inuse = false;
+ if (chan)
+ chan->inuse = false;
mutex_unlock(&virtio_9p_lock);
}
P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
req = p9_tag_lookup(chan->client, rc->tag);
+ req->status = REQ_STATUS_RCVD;
p9_client_cb(chan->client, req);
}
}
/**
* p9_virtio_request - issue a request
- * @t: transport state
- * @tc: &p9_fcall request to transmit
- * @rc: &p9_fcall to put reponse into
+ * @client: client instance issuing the request
+ * @req: request to be issued
*
*/
req->status = REQ_STATUS_SENT;
- if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc)) {
+ if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) {
P9_DPRINTK(P9_DEBUG_TRANS,
"9p debug: virtio rpc add_buf returned failure");
return -EIO;
return 0;
}
+static ssize_t p9_mount_tag_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_chan *chan;
+ struct virtio_device *vdev;
+
+ vdev = dev_to_virtio(dev);
+ chan = vdev->priv;
+
+ return snprintf(buf, chan->tag_len + 1, "%s", chan->tag);
+}
+
+static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
+
/**
* 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.
*
*/
static int p9_virtio_probe(struct virtio_device *vdev)
{
+ __u16 tag_len;
+ char *tag;
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;
}
chan->vdev = vdev;
/* We expect one virtqueue, for requests. */
- chan->vq = vdev->config->find_vq(vdev, 0, req_done);
+ chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
if (IS_ERR(chan->vq)) {
err = PTR_ERR(chan->vq);
goto out_free_vq;
sg_init_table(chan->sg, VIRTQUEUE_NUM);
chan->inuse = false;
- chan->initialized = true;
+ if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
+ vdev->config->get(vdev,
+ offsetof(struct virtio_9p_config, tag_len),
+ &tag_len, sizeof(tag_len));
+ } else {
+ err = -EINVAL;
+ goto out_free_vq;
+ }
+ tag = kmalloc(tag_len, GFP_KERNEL);
+ if (!tag) {
+ err = -ENOMEM;
+ goto out_free_vq;
+ }
+ vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
+ tag, tag_len);
+ chan->tag = tag;
+ chan->tag_len = tag_len;
+ err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ if (err) {
+ kfree(tag);
+ goto out_free_vq;
+ }
+ 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_vq(chan->vq);
+ vdev->config->del_vqs(vdev);
+ kfree(chan);
fail:
- mutex_lock(&virtio_9p_lock);
- chan_index--;
- mutex_unlock(&virtio_9p_lock);
return err;
}
* 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 ret = -ENOENT;
+ int found = 0;
mutex_lock(&virtio_9p_lock);
- while (index < MAX_9P_CHAN) {
- if (chan->initialized && !chan->inuse) {
- chan->inuse = true;
- break;
- } else {
- index++;
- chan = &channels[index];
+ list_for_each_entry(chan, &virtio_chan_list, chan_list) {
+ if (!strncmp(devname, chan->tag, chan->tag_len)) {
+ if (!chan->inuse) {
+ chan->inuse = true;
+ found = 1;
+ break;
+ }
+ ret = -EBUSY;
}
}
mutex_unlock(&virtio_9p_lock);
- if (index >= MAX_9P_CHAN) {
+ if (!found) {
printk(KERN_ERR "9p: no channels available\n");
- return -ENODEV;
+ return ret;
}
client->trans = (void *)chan;
+ client->status = Connected;
chan->client = client;
return 0;
struct virtio_chan *chan = vdev->priv;
BUG_ON(chan->inuse);
+ vdev->config->del_vqs(vdev);
- if (chan->initialized) {
- vdev->config->del_vq(chan->vq);
- chan->initialized = false;
- }
-}
+ mutex_lock(&virtio_9p_lock);
+ list_del(&chan->chan_list);
+ mutex_unlock(&virtio_9p_lock);
+ sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ kfree(chan->tag);
+ kfree(chan);
-#define VIRTIO_ID_9P 9
+}
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
{ 0 },
};
+static unsigned int features[] = {
+ VIRTIO_9P_MOUNT_TAG,
+};
+
/* The standard "struct lguest_driver": */
static struct virtio_driver p9_virtio_drv = {
- .driver.name = KBUILD_MODNAME,
- .driver.owner = THIS_MODULE,
- .id_table = id_table,
- .probe = p9_virtio_probe,
- .remove = p9_virtio_remove,
+ .feature_table = features,
+ .feature_table_size = ARRAY_SIZE(features),
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = p9_virtio_probe,
+ .remove = p9_virtio_remove,
};
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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff