Merge commit 'v2.6.28-rc1' into sched/urgent

1 files changed, 39 insertions, 207 deletions

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 94912e077a55..2d7781ec663b 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -1,12 +1,10 @@
 /*
- * The Guest 9p transport driver
+ * The Virtio 9p transport driver
  *
  * This is a block based transport driver based on the lguest block driver
  * code.
  *
- */
-/*
- *  Copyright (C) 2007 Eric Van Hensbergen, IBM Corporation
+ *  Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation
  *
  *  Based on virtio console driver
  *  Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
@@ -41,6 +39,7 @@
 #include <linux/file.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
+#include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/scatterlist.h>
 #include <linux/virtio.h>
@@ -53,50 +52,6 @@ static DEFINE_MUTEX(virtio_9p_lock);
 /* global which tracks highest initialized channel */
 static int chan_index;
 
-#define P9_INIT_MAXTAG	16
-
-
-/**
- * enum p9_req_status_t - virtio request status
- * @REQ_STATUS_IDLE: request slot unused
- * @REQ_STATUS_SENT: request sent to server
- * @REQ_STATUS_RCVD: response received from server
- * @REQ_STATUS_FLSH: request has been flushed
- *
- * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
- * but use is actually tracked by the idpool structure which handles tag
- * id allocation.
- *
- */
-
-enum p9_req_status_t {
-	REQ_STATUS_IDLE,
-	REQ_STATUS_SENT,
-	REQ_STATUS_RCVD,
-	REQ_STATUS_FLSH,
-};
-
-/**
- * struct p9_req_t - virtio request slots
- * @status: status of this request slot
- * @wq: wait_queue for the client to block on for this request
- *
- * The virtio transport uses an array to track outstanding requests
- * instead of a list.  While this may incurr overhead during initial
- * allocation or expansion, it makes request lookup much easier as the
- * tag id is a index into an array.  (We use tag+1 so that we can accomodate
- * the -1 tag for the T_VERSION request).
- * This also has the nice effect of only having to allocate wait_queues
- * once, instead of constantly allocating and freeing them.  Its possible
- * other resources could benefit from this scheme as well.
- *
- */
-
-struct p9_req_t {
-	int status;
-	wait_queue_head_t *wq;
-};
-
 /**
  * struct virtio_chan - per-instance transport information
  * @initialized: whether the channel is initialized
@@ -121,67 +76,14 @@ static struct virtio_chan {
 
 	spinlock_t lock;
 
+	struct p9_client *client;
 	struct virtio_device *vdev;
 	struct virtqueue *vq;
 
-	struct p9_idpool *tagpool;
-	struct p9_req_t *reqs;
-	int max_tag;
-
 	/* Scatterlist: can be too big for stack. */
 	struct scatterlist sg[VIRTQUEUE_NUM];
 } channels[MAX_9P_CHAN];
 
-/**
- * p9_lookup_tag - Lookup requests by tag
- * @c: virtio channel to lookup tag within
- * @tag: numeric id for transaction
- *
- * this is a simple array lookup, but will grow the
- * request_slots as necessary to accomodate transaction
- * ids which did not previously have a slot.
- *
- * Bugs: there is currently no upper limit on request slots set
- * here, but that should be constrained by the id accounting.
- */
-
-static struct p9_req_t *p9_lookup_tag(struct virtio_chan *c, u16 tag)
-{
-	/* This looks up the original request by tag so we know which
-	 * buffer to read the data into */
-	tag++;
-
-	while (tag >= c->max_tag) {
-		int old_max = c->max_tag;
-		int count;
-
-		if (c->max_tag)
-			c->max_tag *= 2;
-		else
-			c->max_tag = P9_INIT_MAXTAG;
-
-		c->reqs = krealloc(c->reqs, sizeof(struct p9_req_t)*c->max_tag,
-								GFP_ATOMIC);
-		if (!c->reqs) {
-			printk(KERN_ERR "Couldn't grow tag array\n");
-			BUG();
-		}
-		for (count = old_max; count < c->max_tag; count++) {
-			c->reqs[count].status = REQ_STATUS_IDLE;
-			c->reqs[count].wq = kmalloc(sizeof(wait_queue_head_t),
-								GFP_ATOMIC);
-			if (!c->reqs[count].wq) {
-				printk(KERN_ERR "Couldn't grow tag array\n");
-				BUG();
-			}
-			init_waitqueue_head(c->reqs[count].wq);
-		}
-	}
-
-	return &c->reqs[tag];
-}
-
-
 /* How many bytes left in this page. */
 static unsigned int rest_of_page(void *data)
 {
@@ -197,25 +99,13 @@ static unsigned int rest_of_page(void *data)
  *
  */
 
-static void p9_virtio_close(struct p9_trans *trans)
+static void p9_virtio_close(struct p9_client *client)
 {
-	struct virtio_chan *chan = trans->priv;
-	int count;
-	unsigned long flags;
-
-	spin_lock_irqsave(&chan->lock, flags);
-	p9_idpool_destroy(chan->tagpool);
-	for (count = 0; count < chan->max_tag; count++)
-		kfree(chan->reqs[count].wq);
-	kfree(chan->reqs);
-	chan->max_tag = 0;
-	spin_unlock_irqrestore(&chan->lock, flags);
+	struct virtio_chan *chan = client->trans;
 
 	mutex_lock(&virtio_9p_lock);
 	chan->inuse = false;
 	mutex_unlock(&virtio_9p_lock);
-
-	kfree(trans);
 }
 
 /**
@@ -236,17 +126,16 @@ static void req_done(struct virtqueue *vq)
 	struct virtio_chan *chan = vq->vdev->priv;
 	struct p9_fcall *rc;
 	unsigned int len;
-	unsigned long flags;
 	struct p9_req_t *req;
 
-	spin_lock_irqsave(&chan->lock, flags);
+	P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n");
+
 	while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) {
-		req = p9_lookup_tag(chan, rc->tag);
-		req->status = REQ_STATUS_RCVD;
-		wake_up(req->wq);
+		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);
+		p9_client_cb(chan->client, req);
 	}
-	/* In case queue is stopped waiting for more buffers. */
-	spin_unlock_irqrestore(&chan->lock, flags);
 }
 
 /**
@@ -283,8 +172,14 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
 	return index-start;
 }
 
+/* We don't currently allow canceling of virtio requests */
+static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
+{
+	return 1;
+}
+
 /**
- * p9_virtio_rpc - issue a request and wait for a response
+ * p9_virtio_request - issue a request
  * @t: transport state
  * @tc: &p9_fcall request to transmit
  * @rc: &p9_fcall to put reponse into
@@ -292,44 +187,22 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
  */
 
 static int
-p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
+p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 {
 	int in, out;
-	int n, err, size;
-	struct virtio_chan *chan = t->priv;
-	char *rdata;
-	struct p9_req_t *req;
-	unsigned long flags;
-
-	if (*rc == NULL) {
-		*rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL);
-		if (!*rc)
-			return -ENOMEM;
-	}
-
-	rdata = (char *)*rc+sizeof(struct p9_fcall);
-
-	n = P9_NOTAG;
-	if (tc->id != P9_TVERSION) {
-		n = p9_idpool_get(chan->tagpool);
-		if (n < 0)
-			return -ENOMEM;
-	}
-
-	spin_lock_irqsave(&chan->lock, flags);
-	req = p9_lookup_tag(chan, n);
-	spin_unlock_irqrestore(&chan->lock, flags);
+	struct virtio_chan *chan = client->trans;
+	char *rdata = (char *)req->rc+sizeof(struct p9_fcall);
 
-	p9_set_tag(tc, n);
+	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");
 
-	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n);
-
-	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size);
-	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize);
+	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata,
+								req->tc->size);
+	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata,
+								client->msize);
 
 	req->status = REQ_STATUS_SENT;
 
-	if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, tc)) {
+	if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc)) {
 		P9_DPRINTK(P9_DEBUG_TRANS,
 			"9p debug: virtio rpc add_buf returned failure");
 		return -EIO;
@@ -337,31 +210,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 
 	chan->vq->vq_ops->kick(chan->vq);
 
-	wait_event(*req->wq, req->status == REQ_STATUS_RCVD);
-
-	size = le32_to_cpu(*(__le32 *) rdata);
-
-	err = p9_deserialize_fcall(rdata, size, *rc, t->extended);
-	if (err < 0) {
-		P9_DPRINTK(P9_DEBUG_TRANS,
-			"9p debug: virtio rpc deserialize returned %d\n", err);
-		return err;
-	}
-
-#ifdef CONFIG_NET_9P_DEBUG
-	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-		char buf[150];
-
-		p9_printfcall(buf, sizeof(buf), *rc, t->extended);
-		printk(KERN_NOTICE ">>> %p %s\n", t, buf);
-	}
-#endif
-
-	if (n != P9_NOTAG && p9_idpool_check(n, chan->tagpool))
-		p9_idpool_put(n, chan->tagpool);
-
-	req->status = REQ_STATUS_IDLE;
-
+	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
 	return 0;
 }
 
@@ -422,10 +271,9 @@ fail:
 
 /**
  * p9_virtio_create - allocate a new virtio channel
+ * @client: client instance invoking this transport
  * @devname: string identifying the channel to connect to (unused)
  * @args: args passed from sys_mount() for per-transport options (unused)
- * @msize: requested maximum packet size
- * @extended: 9p2000.u enabled flag
  *
  * This sets up a transport channel for 9p communication.  Right now
  * we only match the first available channel, but eventually we couldlook up
@@ -441,11 +289,9 @@ fail:
  *
  */
 
-static struct p9_trans *
-p9_virtio_create(const char *devname, char *args, int msize,
-							unsigned char extended)
+static int
+p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 {
-	struct p9_trans *trans;
 	struct virtio_chan *chan = channels;
 	int index = 0;
 
@@ -463,30 +309,13 @@ p9_virtio_create(const char *devname, char *args, int msize,
 
 	if (index >= MAX_9P_CHAN) {
 		printk(KERN_ERR "9p: no channels available\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	}
 
-	chan->tagpool = p9_idpool_create();
-	if (IS_ERR(chan->tagpool)) {
-		printk(KERN_ERR "9p: couldn't allocate tagpool\n");
-		return ERR_PTR(-ENOMEM);
-	}
-	p9_idpool_get(chan->tagpool); /* reserve tag 0 */
-	chan->max_tag = 0;
-	chan->reqs = NULL;
-
-	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
-	if (!trans) {
-		printk(KERN_ERR "9p: couldn't allocate transport\n");
-		return ERR_PTR(-ENOMEM);
-	}
-	trans->extended = extended;
-	trans->msize = msize;
-	trans->close = p9_virtio_close;
-	trans->rpc = p9_virtio_rpc;
-	trans->priv = chan;
+	client->trans = (void *)chan;
+	chan->client = client;
 
-	return trans;
+	return 0;
 }
 
 /**
@@ -526,6 +355,9 @@ static struct virtio_driver p9_virtio_drv = {
 static struct p9_trans_module p9_virtio_trans = {
 	.name = "virtio",
 	.create = p9_virtio_create,
+	.close = p9_virtio_close,
+	.request = p9_virtio_request,
+	.cancel = p9_virtio_cancel,
 	.maxsize = PAGE_SIZE*16,
 	.def = 0,
 	.owner = THIS_MODULE,