9p: patches for 4.1 merge window

Some accumulated cleanup patches for kerneldoc and unused variables
 as well as some lock bug fixes and adding privateport option for RDMA.
 
 A quick check shows some merge-conflicts versus current-tip on
    9p: use unsigned integers for nwqid/count
 If you would prefer I can rebase, remerge and fix the patch but didn't
 want to do that and look the for-next references.
 
 Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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Merge tag 'for-linus-4.1-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

Pull 9pfs updates from Eric Van Hensbergen:
 "Some accumulated cleanup patches for kerneldoc and unused variables as
  well as some lock bug fixes and adding privateport option for RDMA"

* tag 'for-linus-4.1-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  net/9p: add a privport option for RDMA transport.
  fs/9p: Initialize status in v9fs_file_do_lock.
  net/9p: Initialize opts->privport as it should be.
  net/9p: use memcpy() instead of snprintf() in p9_mount_tag_show()
  9p: use unsigned integers for nwqid/count
  9p: do not crash on unknown lock status code
  9p: fix error handling in v9fs_file_do_lock
  9p: remove unused variable in p9_fd_create()
  9p: kerneldoc warning fixes

fs/9p/v9fs.h

@@ -78,7 +78,6 @@ enum p9_cache_modes {
  * @cache: cache mode of type &p9_cache_modes
  * @cachetag: the tag of the cache associated with this session
  * @fscache: session cookie associated with FS-Cache
- * @options: copy of options string given by user
  * @uname: string user name to mount hierarchy as
  * @aname: mount specifier for remote hierarchy
  * @maxdata: maximum data to be sent/recvd per protocol message

fs/9p/vfs_addr.c

@@ -231,9 +231,7 @@ static int v9fs_launder_page(struct page *page)
 /**
  * v9fs_direct_IO - 9P address space operation for direct I/O
  * @iocb: target I/O control block
- * @iov: array of vectors that define I/O buffer
  * @pos: offset in file to begin the operation
- * @nr_segs: size of iovec array
  *
  * The presence of v9fs_direct_IO() in the address space ops vector
  * allowes open() O_DIRECT flags which would have failed otherwise.

fs/9p/vfs_file.c

@@ -151,7 +151,7 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
 {
 	struct p9_flock flock;
 	struct p9_fid *fid;
-	uint8_t status;
+	uint8_t status = P9_LOCK_ERROR;
 	int res = 0;
 	unsigned char fl_type;
 
@@ -196,7 +196,7 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
 	for (;;) {
 		res = p9_client_lock_dotl(fid, &flock, &status);
 		if (res < 0)
-			break;
+			goto out_unlock;
 
 		if (status != P9_LOCK_BLOCKED)
 			break;
@@ -214,14 +214,16 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
 	case P9_LOCK_BLOCKED:
 		res = -EAGAIN;
 		break;
+	default:
+		WARN_ONCE(1, "unknown lock status code: %d\n", status);
+		/* fallthough */
 	case P9_LOCK_ERROR:
 	case P9_LOCK_GRACE:
 		res = -ENOLCK;
 		break;
-	default:
-		BUG();
 	}
 
+out_unlock:
 	/*
 	 * incase server returned error for lock request, revert
 	 * it locally

net/9p/protocol.c

@@ -275,7 +275,7 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
 			}
 			break;
 		case 'R':{
-				int16_t *nwqid = va_arg(ap, int16_t *);
+				uint16_t *nwqid = va_arg(ap, uint16_t *);
 				struct p9_qid **wqids =
 				    va_arg(ap, struct p9_qid **);
 
@@ -440,7 +440,7 @@ p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 						 stbuf->n_gid, stbuf->n_muid);
 			} break;
 		case 'V':{
-				int32_t count = va_arg(ap, int32_t);
+				uint32_t count = va_arg(ap, uint32_t);
 				struct iov_iter *from =
 						va_arg(ap, struct iov_iter *);
 				errcode = p9pdu_writef(pdu, proto_version, "d",
@@ -471,7 +471,7 @@ p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 			}
 			break;
 		case 'R':{
-				int16_t nwqid = va_arg(ap, int);
+				uint16_t nwqid = va_arg(ap, int);
 				struct p9_qid *wqids =
 				    va_arg(ap, struct p9_qid *);
 

net/9p/trans_fd.c

@@ -734,6 +734,7 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
 	opts->port = P9_PORT;
 	opts->rfd = ~0;
 	opts->wfd = ~0;
+	opts->privport = 0;
 
 	if (!params)
 		return 0;
@@ -1013,7 +1014,6 @@ p9_fd_create(struct p9_client *client, const char *addr, char *args)
 {
 	int err;
 	struct p9_fd_opts opts;
-	struct p9_trans_fd *p;
 
 	parse_opts(args, &opts);
 
@@ -1026,7 +1026,6 @@ p9_fd_create(struct p9_client *client, const char *addr, char *args)
 	if (err < 0)
 		return err;
 
-	p = (struct p9_trans_fd *) client->trans;
 	p9_conn_create(client);
 
 	return 0;

net/9p/trans_rdma.c

@@ -139,6 +139,7 @@ struct p9_rdma_opts {
 	int sq_depth;
 	int rq_depth;
 	long timeout;
+	int privport;
 };
 
 /*
@@ -146,7 +147,10 @@ struct p9_rdma_opts {
  */
 enum {
 	/* Options that take integer arguments */
-	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
+	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
+	/* Options that take no argument */
+	Opt_privport,
+	Opt_err,
 };
 
 static match_table_t tokens = {
@@ -154,6 +158,7 @@ static match_table_t tokens = {
 	{Opt_sq_depth, "sq=%u"},
 	{Opt_rq_depth, "rq=%u"},
 	{Opt_timeout, "timeout=%u"},
+	{Opt_privport, "privport"},
 	{Opt_err, NULL},
 };
 
@@ -175,6 +180,7 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 	opts->sq_depth = P9_RDMA_SQ_DEPTH;
 	opts->rq_depth = P9_RDMA_RQ_DEPTH;
 	opts->timeout = P9_RDMA_TIMEOUT;
+	opts->privport = 0;
 
 	if (!params)
 		return 0;
@@ -193,13 +199,13 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 		if (!*p)
 			continue;
 		token = match_token(p, tokens, args);
-		if (token == Opt_err)
-			continue;
-		r = match_int(&args[0], &option);
-		if (r < 0) {
-			p9_debug(P9_DEBUG_ERROR,
-				 "integer field, but no integer?\n");
-			continue;
+		if ((token != Opt_err) && (token != Opt_privport)) {
+			r = match_int(&args[0], &option);
+			if (r < 0) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "integer field, but no integer?\n");
+				continue;
+			}
 		}
 		switch (token) {
 		case Opt_port:
@@ -214,6 +220,9 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 		case Opt_timeout:
 			opts->timeout = option;
 			break;
+		case Opt_privport:
+			opts->privport = 1;
+			break;
 		default:
 			continue;
 		}
@@ -607,6 +616,23 @@ static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
 	return 0;
 }
 
+static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
+{
+	struct sockaddr_in cl = {
+		.sin_family = AF_INET,
+		.sin_addr.s_addr = htonl(INADDR_ANY),
+	};
+	int port, err = -EINVAL;
+
+	for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
+		cl.sin_port = htons((ushort)port);
+		err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
+		if (err != -EADDRINUSE)
+			break;
+	}
+	return err;
+}
+
 /**
  * trans_create_rdma - Transport method for creating atransport instance
  * @client: client instance
@@ -642,6 +668,16 @@ rdma_create_trans(struct p9_client *client, const char *addr, char *args)
 	/* Associate the client with the transport */
 	client->trans = rdma;
 
+	/* Bind to a privileged port if we need to */
+	if (opts.privport) {
+		err = p9_rdma_bind_privport(rdma);
+		if (err < 0) {
+			pr_err("%s (%d): problem binding to privport: %d\n",
+			       __func__, task_pid_nr(current), -err);
+			goto error;
+		}
+	}
+
 	/* Resolve the server's address */
 	rdma->addr.sin_family = AF_INET;
 	rdma->addr.sin_addr.s_addr = in_aton(addr);

net/9p/trans_virtio.c

@@ -525,7 +525,10 @@ static ssize_t p9_mount_tag_show(struct device *dev,
 	vdev = dev_to_virtio(dev);
 	chan = vdev->priv;
 
-	return snprintf(buf, chan->tag_len + 1, "%s", chan->tag);
+	memcpy(buf, chan->tag, chan->tag_len);
+	buf[chan->tag_len] = 0;
+
+	return chan->tag_len + 1;
 }
 
 static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);