1 files changed, 52 insertions, 16 deletions

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index b24a4fb0f0a2..10c2dd486438 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -22,12 +22,11 @@
 #include <linux/un.h>
 #include <linux/uaccess.h>
 #include <linux/inet.h>
-#include <linux/idr.h>
 #include <linux/file.h>
 #include <linux/highmem.h>
 #include <linux/slab.h>
 #include <net/9p/9p.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
 #include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/scatterlist.h>
@@ -199,7 +198,7 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
 /* Reply won't come, so drop req ref */
 static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req)
 {
-	p9_req_put(req);
+	p9_req_put(client, req);
 	return 0;
 }
 
@@ -263,7 +262,7 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 
 	p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
 
-	req->status = REQ_STATUS_SENT;
+	WRITE_ONCE(req->status, REQ_STATUS_SENT);
 req_retry:
 	spin_lock_irqsave(&chan->lock, flags);
 
@@ -331,7 +330,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
 			if (err == -ERESTARTSYS)
 				return err;
 		}
-		n = iov_iter_get_pages_alloc(data, pages, count, offs);
+		n = iov_iter_get_pages_alloc2(data, pages, count, offs);
 		if (n < 0)
 			return n;
 		*need_drop = 1;
@@ -373,10 +372,40 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
 				(*pages)[index] = kmap_to_page(p);
 			p += PAGE_SIZE;
 		}
+		iov_iter_advance(data, len);
 		return len;
 	}
 }
 
+static void handle_rerror(struct p9_req_t *req, int in_hdr_len,
+			  size_t offs, struct page **pages)
+{
+	unsigned size, n;
+	void *to = req->rc.sdata + in_hdr_len;
+
+	// Fits entirely into the static data?  Nothing to do.
+	if (req->rc.size < in_hdr_len || !pages)
+		return;
+
+	// Really long error message?  Tough, truncate the reply.  Might get
+	// rejected (we can't be arsed to adjust the size encoded in header,
+	// or string size for that matter), but it wouldn't be anything valid
+	// anyway.
+	if (unlikely(req->rc.size > P9_ZC_HDR_SZ))
+		req->rc.size = P9_ZC_HDR_SZ;
+
+	// data won't span more than two pages
+	size = req->rc.size - in_hdr_len;
+	n = PAGE_SIZE - offs;
+	if (size > n) {
+		memcpy_from_page(to, *pages++, offs, n);
+		offs = 0;
+		to += n;
+		size -= n;
+	}
+	memcpy_from_page(to, *pages, offs, size);
+}
+
 /**
  * p9_virtio_zc_request - issue a zero copy request
  * @client: client instance issuing the request
@@ -399,7 +428,7 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
 	struct page **in_pages = NULL, **out_pages = NULL;
 	struct virtio_chan *chan = client->trans;
 	struct scatterlist *sgs[4];
-	size_t offs;
+	size_t offs = 0;
 	int need_drop = 0;
 	int kicked = 0;
 
@@ -439,7 +468,7 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
 			inlen = n;
 		}
 	}
-	req->status = REQ_STATUS_SENT;
+	WRITE_ONCE(req->status, REQ_STATUS_SENT);
 req_retry_pinned:
 	spin_lock_irqsave(&chan->lock, flags);
 
@@ -472,8 +501,8 @@ req_retry_pinned:
 
 	if (in_pages) {
 		sgs[out_sgs + in_sgs++] = chan->sg + out + in;
-		in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
-				     in_pages, in_nr_pages, offs, inlen);
+		pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
+			       in_pages, in_nr_pages, offs, inlen);
 	}
 
 	BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
@@ -502,7 +531,13 @@ req_retry_pinned:
 	spin_unlock_irqrestore(&chan->lock, flags);
 	kicked = 1;
 	p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
-	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
+	err = wait_event_killable(req->wq,
+			          READ_ONCE(req->status) >= REQ_STATUS_RCVD);
+	// RERROR needs reply (== error string) in static data
+	if (READ_ONCE(req->status) == REQ_STATUS_RCVD &&
+	    unlikely(req->rc.sdata[4] == P9_RERROR))
+		handle_rerror(req, in_hdr_len, offs, in_pages);
+
 	/*
 	 * Non kernel buffers are pinned, unpin them
 	 */
@@ -523,7 +558,7 @@ err_out:
 	kvfree(out_pages);
 	if (!kicked) {
 		/* reply won't come */
-		p9_req_put(req);
+		p9_req_put(client, req);
 	}
 	return err;
 }
@@ -644,8 +679,7 @@ 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)
+ * @fc: the filesystem context
  *
  * This sets up a transport channel for 9p communication.  Right now
  * we only match the first available channel, but eventually we could look up
@@ -656,8 +690,9 @@ fail:
  */
 
 static int
-p9_virtio_create(struct p9_client *client, const char *devname, char *args)
+p9_virtio_create(struct p9_client *client, struct fs_context *fc)
 {
+	const char *devname = fc->source;
 	struct virtio_chan *chan;
 	int ret = -ENOENT;
 	int found = 0;
@@ -746,7 +781,6 @@ static struct virtio_driver p9_virtio_drv = {
 	.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,
@@ -767,7 +801,9 @@ static struct p9_trans_module p9_virtio_trans = {
 	 * page in zero copy.
 	 */
 	.maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
-	.def = 1,
+	.pooled_rbuffers = false,
+	.def = true,
+	.supports_vmalloc = false,
 	.owner = THIS_MODULE,
 };