nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 202 insertions, 88 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 83867ef348df..2126ab185045 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -27,6 +27,8 @@
 #include <linux/net.h>
 #include <linux/delay.h>
 #include <linux/freezer.h>
+#include <linux/tcp.h>
+#include <linux/highmem.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 #include <linux/mempool.h>
@@ -109,8 +111,8 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
 	mempool_free(midEntry, cifs_mid_poolp);
 }
 
-static void
-delete_mid(struct mid_q_entry *mid)
+void
+cifs_delete_mid(struct mid_q_entry *mid)
 {
 	spin_lock(&GlobalMid_Lock);
 	list_del(&mid->qhead);
@@ -119,18 +121,29 @@ delete_mid(struct mid_q_entry *mid)
 	DeleteMidQEntry(mid);
 }
 
+/*
+ * smb_send_kvec - send an array of kvecs to the server
+ * @server:	Server to send the data to
+ * @iov:	Pointer to array of kvecs
+ * @n_vec:	length of kvec array
+ * @sent:	amount of data sent on socket is stored here
+ *
+ * Our basic "send data to server" function. Should be called with srv_mutex
+ * held. The caller is responsible for handling the results.
+ */
 static int
-smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
+smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
+		size_t *sent)
 {
 	int rc = 0;
 	int i = 0;
 	struct msghdr smb_msg;
-	unsigned int len = iov[0].iov_len;
-	unsigned int total_len;
-	int first_vec = 0;
-	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
+	unsigned int remaining;
+	size_t first_vec = 0;
 	struct socket *ssocket = server->ssocket;
 
+	*sent = 0;
+
 	if (ssocket == NULL)
 		return -ENOTSOCK; /* BB eventually add reconnect code here */
 
@@ -143,56 +156,60 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 	else
 		smb_msg.msg_flags = MSG_NOSIGNAL;
 
-	total_len = 0;
+	remaining = 0;
 	for (i = 0; i < n_vec; i++)
-		total_len += iov[i].iov_len;
-
-	cFYI(1, "Sending smb:  total_len %d", total_len);
-	dump_smb(iov[0].iov_base, len);
+		remaining += iov[i].iov_len;
 
 	i = 0;
-	while (total_len) {
+	while (remaining) {
+		/*
+		 * If blocking send, we try 3 times, since each can block
+		 * for 5 seconds. For nonblocking  we have to try more
+		 * but wait increasing amounts of time allowing time for
+		 * socket to clear.  The overall time we wait in either
+		 * case to send on the socket is about 15 seconds.
+		 * Similarly we wait for 15 seconds for a response from
+		 * the server in SendReceive[2] for the server to send
+		 * a response back for most types of requests (except
+		 * SMB Write past end of file which can be slow, and
+		 * blocking lock operations). NFS waits slightly longer
+		 * than CIFS, but this can make it take longer for
+		 * nonresponsive servers to be detected and 15 seconds
+		 * is more than enough time for modern networks to
+		 * send a packet.  In most cases if we fail to send
+		 * after the retries we will kill the socket and
+		 * reconnect which may clear the network problem.
+		 */
 		rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
-				    n_vec - first_vec, total_len);
-		if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
+				    n_vec - first_vec, remaining);
+		if (rc == -ENOSPC || rc == -EAGAIN) {
 			i++;
-			/*
-			 * If blocking send we try 3 times, since each can block
-			 * for 5 seconds. For nonblocking  we have to try more
-			 * but wait increasing amounts of time allowing time for
-			 * socket to clear.  The overall time we wait in either
-			 * case to send on the socket is about 15 seconds.
-			 * Similarly we wait for 15 seconds for a response from
-			 * the server in SendReceive[2] for the server to send
-			 * a response back for most types of requests (except
-			 * SMB Write past end of file which can be slow, and
-			 * blocking lock operations). NFS waits slightly longer
-			 * than CIFS, but this can make it take longer for
-			 * nonresponsive servers to be detected and 15 seconds
-			 * is more than enough time for modern networks to
-			 * send a packet.  In most cases if we fail to send
-			 * after the retries we will kill the socket and
-			 * reconnect which may clear the network problem.
-			 */
-			if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
-				cERROR(1, "sends on sock %p stuck for 15 seconds",
-				    ssocket);
+			if (i >= 14 || (!server->noblocksnd && (i > 2))) {
+				cERROR(1, "sends on sock %p stuck for 15 "
+					  "seconds", ssocket);
 				rc = -EAGAIN;
 				break;
 			}
 			msleep(1 << i);
 			continue;
 		}
+
 		if (rc < 0)
 			break;
 
-		if (rc == total_len) {
-			total_len = 0;
+		/* send was at least partially successful */
+		*sent += rc;
+
+		if (rc == remaining) {
+			remaining = 0;
 			break;
-		} else if (rc > total_len) {
-			cERROR(1, "sent %d requested %d", rc, total_len);
+		}
+
+		if (rc > remaining) {
+			cERROR(1, "sent %d requested %d", rc, remaining);
 			break;
 		}
+
 		if (rc == 0) {
 			/* should never happen, letting socket clear before
 			   retrying is our only obvious option here */
@@ -200,7 +217,9 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 			msleep(500);
 			continue;
 		}
-		total_len -= rc;
+
+		remaining -= rc;
+
 		/* the line below resets i */
 		for (i = first_vec; i < n_vec; i++) {
 			if (iov[i].iov_len) {
@@ -215,16 +234,97 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 				}
 			}
 		}
+
 		i = 0; /* in case we get ENOSPC on the next send */
+		rc = 0;
 	}
+	return rc;
+}
+
+/**
+ * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
+ * @rqst: pointer to smb_rqst
+ * @idx: index into the array of the page
+ * @iov: pointer to struct kvec that will hold the result
+ *
+ * Helper function to convert a slot in the rqst->rq_pages array into a kvec.
+ * The page will be kmapped and the address placed into iov_base. The length
+ * will then be adjusted according to the ptailoff.
+ */
+void
+cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
+			struct kvec *iov)
+{
+	/*
+	 * FIXME: We could avoid this kmap altogether if we used
+	 * kernel_sendpage instead of kernel_sendmsg. That will only
+	 * work if signing is disabled though as sendpage inlines the
+	 * page directly into the fraglist. If userspace modifies the
+	 * page after we calculate the signature, then the server will
+	 * reject it and may break the connection. kernel_sendmsg does
+	 * an extra copy of the data and avoids that issue.
+	 */
+	iov->iov_base = kmap(rqst->rq_pages[idx]);
+
+	/* if last page, don't send beyond this offset into page */
+	if (idx == (rqst->rq_npages - 1))
+		iov->iov_len = rqst->rq_tailsz;
+	else
+		iov->iov_len = rqst->rq_pagesz;
+}
+
+static int
+smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+{
+	int rc;
+	struct kvec *iov = rqst->rq_iov;
+	int n_vec = rqst->rq_nvec;
+	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
+	unsigned int i;
+	size_t total_len = 0, sent;
+	struct socket *ssocket = server->ssocket;
+	int val = 1;
+
+	cFYI(1, "Sending smb: smb_len=%u", smb_buf_length);
+	dump_smb(iov[0].iov_base, iov[0].iov_len);
+
+	/* cork the socket */
+	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+				(char *)&val, sizeof(val));
+
+	rc = smb_send_kvec(server, iov, n_vec, &sent);
+	if (rc < 0)
+		goto uncork;
+
+	total_len += sent;
+
+	/* now walk the page array and send each page in it */
+	for (i = 0; i < rqst->rq_npages; i++) {
+		struct kvec p_iov;
+
+		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
+		rc = smb_send_kvec(server, &p_iov, 1, &sent);
+		kunmap(rqst->rq_pages[i]);
+		if (rc < 0)
+			break;
+
+		total_len += sent;
+	}
+
+uncork:
+	/* uncork it */
+	val = 0;
+	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+				(char *)&val, sizeof(val));
 
 	if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
-		cFYI(1, "partial send (%d remaining), terminating session",
-			total_len);
-		/* If we have only sent part of an SMB then the next SMB
-		   could be taken as the remainder of this one.  We need
-		   to kill the socket so the server throws away the partial
-		   SMB */
+		cFYI(1, "partial send (wanted=%u sent=%zu): terminating "
+			"session", smb_buf_length + 4, total_len);
+		/*
+		 * If we have only sent part of an SMB then the next SMB could
+		 * be taken as the remainder of this one. We need to kill the
+		 * socket so the server throws away the partial SMB
+		 */
 		server->tcpStatus = CifsNeedReconnect;
 	}
 
@@ -236,6 +336,15 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 	return rc;
 }
 
+static int
+smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
+{
+	struct smb_rqst rqst = { .rq_iov = iov,
+				 .rq_nvec = n_vec };
+
+	return smb_send_rqst(server, &rqst);
+}
+
 int
 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 	 unsigned int smb_buf_length)
@@ -345,12 +454,11 @@ wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
 	return 0;
 }
 
-int
-cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
-			 unsigned int nvec, struct mid_q_entry **ret_mid)
+struct mid_q_entry *
+cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 {
 	int rc;
-	struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
+	struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 	struct mid_q_entry *mid;
 
 	/* enable signing if server requires it */
@@ -359,16 +467,15 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
 
 	mid = AllocMidQEntry(hdr, server);
 	if (mid == NULL)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	rc = cifs_sign_smbv(iov, nvec, server, &mid->sequence_number);
+	rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
 	if (rc) {
 		DeleteMidQEntry(mid);
-		return rc;
+		return ERR_PTR(rc);
 	}
 
-	*ret_mid = mid;
-	return 0;
+	return mid;
 }
 
 /*
@@ -376,9 +483,9 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
  * the result. Caller is responsible for dealing with timeouts.
  */
 int
-cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
-		unsigned int nvec, mid_receive_t *receive,
-		mid_callback_t *callback, void *cbdata, const int flags)
+cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
+		mid_receive_t *receive, mid_callback_t *callback,
+		void *cbdata, const int flags)
 {
 	int rc, timeout, optype;
 	struct mid_q_entry *mid;
@@ -391,12 +498,12 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
 		return rc;
 
 	mutex_lock(&server->srv_mutex);
-	rc = server->ops->setup_async_request(server, iov, nvec, &mid);
-	if (rc) {
+	mid = server->ops->setup_async_request(server, rqst);
+	if (IS_ERR(mid)) {
 		mutex_unlock(&server->srv_mutex);
 		add_credits(server, 1, optype);
 		wake_up(&server->request_q);
-		return rc;
+		return PTR_ERR(mid);
 	}
 
 	mid->receive = receive;
@@ -411,7 +518,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
 
 
 	cifs_in_send_inc(server);
-	rc = smb_sendv(server, iov, nvec);
+	rc = smb_send_rqst(server, rqst);
 	cifs_in_send_dec(server);
 	cifs_save_when_sent(mid);
 	mutex_unlock(&server->srv_mutex);
@@ -419,7 +526,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
 	if (rc == 0)
 		return 0;
 
-	delete_mid(mid);
+	cifs_delete_mid(mid);
 	add_credits(server, 1, optype);
 	wake_up(&server->request_q);
 	return rc;
@@ -503,35 +610,40 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 	/* convert the length into a more usable form */
 	if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
 		struct kvec iov;
+		int rc = 0;
+		struct smb_rqst rqst = { .rq_iov = &iov,
+					 .rq_nvec = 1 };
 
 		iov.iov_base = mid->resp_buf;
 		iov.iov_len = len;
 		/* FIXME: add code to kill session */
-		if (cifs_verify_signature(&iov, 1, server,
-					  mid->sequence_number + 1) != 0)
-			cERROR(1, "Unexpected SMB signature");
+		rc = cifs_verify_signature(&rqst, server,
+					   mid->sequence_number + 1);
+		if (rc)
+			cERROR(1, "SMB signature verification returned error = "
+			       "%d", rc);
 	}
 
 	/* BB special case reconnect tid and uid here? */
 	return map_smb_to_linux_error(mid->resp_buf, log_error);
 }
 
-int
-cifs_setup_request(struct cifs_ses *ses, struct kvec *iov,
-		   unsigned int nvec, struct mid_q_entry **ret_mid)
+struct mid_q_entry *
+cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 {
 	int rc;
-	struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
+	struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 	struct mid_q_entry *mid;
 
 	rc = allocate_mid(ses, hdr, &mid);
 	if (rc)
-		return rc;
-	rc = cifs_sign_smbv(iov, nvec, ses->server, &mid->sequence_number);
-	if (rc)
-		delete_mid(mid);
-	*ret_mid = mid;
-	return rc;
+		return ERR_PTR(rc);
+	rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
+	if (rc) {
+		cifs_delete_mid(mid);
+		return ERR_PTR(rc);
+	}
+	return mid;
 }
 
 int
@@ -544,6 +656,8 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 	struct mid_q_entry *midQ;
 	char *buf = iov[0].iov_base;
 	unsigned int credits = 1;
+	struct smb_rqst rqst = { .rq_iov = iov,
+				 .rq_nvec = n_vec };
 
 	timeout = flags & CIFS_TIMEOUT_MASK;
 	optype = flags & CIFS_OP_MASK;
@@ -581,13 +695,13 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_lock(&ses->server->srv_mutex);
 
-	rc = ses->server->ops->setup_request(ses, iov, n_vec, &midQ);
-	if (rc) {
+	midQ = ses->server->ops->setup_request(ses, &rqst);
+	if (IS_ERR(midQ)) {
 		mutex_unlock(&ses->server->srv_mutex);
 		cifs_small_buf_release(buf);
 		/* Update # of requests on wire to server */
 		add_credits(ses->server, 1, optype);
-		return rc;
+		return PTR_ERR(midQ);
 	}
 
 	midQ->mid_state = MID_REQUEST_SUBMITTED;
@@ -649,11 +763,11 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 	rc = ses->server->ops->check_receive(midQ, ses->server,
 					     flags & CIFS_LOG_ERROR);
 
-	/* mark it so buf will not be freed by delete_mid */
+	/* mark it so buf will not be freed by cifs_delete_mid */
 	if ((flags & CIFS_NO_RESP) == 0)
 		midQ->resp_buf = NULL;
 out:
-	delete_mid(midQ);
+	cifs_delete_mid(midQ);
 	add_credits(ses->server, credits, optype);
 
 	return rc;
@@ -759,7 +873,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 	memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
 	rc = cifs_check_receive(midQ, ses->server, 0);
 out:
-	delete_mid(midQ);
+	cifs_delete_mid(midQ);
 	add_credits(ses->server, 1, 0);
 
 	return rc;
@@ -843,7 +957,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 	if (rc) {
-		delete_mid(midQ);
+		cifs_delete_mid(midQ);
 		mutex_unlock(&ses->server->srv_mutex);
 		return rc;
 	}
@@ -856,7 +970,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 	mutex_unlock(&ses->server->srv_mutex);
 
 	if (rc < 0) {
-		delete_mid(midQ);
+		cifs_delete_mid(midQ);
 		return rc;
 	}
 
@@ -877,7 +991,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 			   blocking lock to return. */
 			rc = send_cancel(ses->server, in_buf, midQ);
 			if (rc) {
-				delete_mid(midQ);
+				cifs_delete_mid(midQ);
 				return rc;
 			}
 		} else {
@@ -889,7 +1003,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 			/* If we get -ENOLCK back the lock may have
 			   already been removed. Don't exit in this case. */
 			if (rc && rc != -ENOLCK) {
-				delete_mid(midQ);
+				cifs_delete_mid(midQ);
 				return rc;
 			}
 		}
@@ -926,7 +1040,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 	memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
 	rc = cifs_check_receive(midQ, ses->server, 0);
 out:
-	delete_mid(midQ);
+	cifs_delete_mid(midQ);
 	if (rstart && rc == -EACCES)
 		return -ERESTARTSYS;
 	return rc;