Merge branch 'sendmsg.cifs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull cifs iovec cleanups from Al Viro.

* 'sendmsg.cifs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  cifs: don't bother with kmap on read_pages side
  cifs_readv_receive: use cifs_read_from_socket()
  cifs: no need to wank with copying and advancing iovec on recvmsg side either
  cifs: quit playing games with draining iovecs
  cifs: merge the hash calculation helpers

1 files changed, 35 insertions, 92 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 1bb258af1648..66736f57b5ab 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -501,99 +501,34 @@ server_unresponsive(struct TCP_Server_Info *server)
 	return false;
 }
 
-/*
- * kvec_array_init - clone a kvec array, and advance into it
- * @new:	pointer to memory for cloned array
- * @iov:	pointer to original array
- * @nr_segs:	number of members in original array
- * @bytes:	number of bytes to advance into the cloned array
- *
- * This function will copy the array provided in iov to a section of memory
- * and advance the specified number of bytes into the new array. It returns
- * the number of segments in the new array. "new" must be at least as big as
- * the original iov array.
- */
-static unsigned int
-kvec_array_init(struct kvec *new, struct kvec *iov, unsigned int nr_segs,
-		size_t bytes)
-{
-	size_t base = 0;
-
-	while (bytes || !iov->iov_len) {
-		int copy = min(bytes, iov->iov_len);
-
-		bytes -= copy;
-		base += copy;
-		if (iov->iov_len == base) {
-			iov++;
-			nr_segs--;
-			base = 0;
-		}
-	}
-	memcpy(new, iov, sizeof(*iov) * nr_segs);
-	new->iov_base += base;
-	new->iov_len -= base;
-	return nr_segs;
-}
-
-static struct kvec *
-get_server_iovec(struct TCP_Server_Info *server, unsigned int nr_segs)
-{
-	struct kvec *new_iov;
-
-	if (server->iov && nr_segs <= server->nr_iov)
-		return server->iov;
-
-	/* not big enough -- allocate a new one and release the old */
-	new_iov = kmalloc(sizeof(*new_iov) * nr_segs, GFP_NOFS);
-	if (new_iov) {
-		kfree(server->iov);
-		server->iov = new_iov;
-		server->nr_iov = nr_segs;
-	}
-	return new_iov;
-}
-
-int
-cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
-		       unsigned int nr_segs, unsigned int to_read)
+static int
+cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
 	int length = 0;
 	int total_read;
-	unsigned int segs;
-	struct msghdr smb_msg;
-	struct kvec *iov;
-
-	iov = get_server_iovec(server, nr_segs);
-	if (!iov)
-		return -ENOMEM;
 
-	smb_msg.msg_control = NULL;
-	smb_msg.msg_controllen = 0;
+	smb_msg->msg_control = NULL;
+	smb_msg->msg_controllen = 0;
 
-	for (total_read = 0; to_read; total_read += length, to_read -= length) {
+	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 		try_to_freeze();
 
-		if (server_unresponsive(server)) {
-			total_read = -ECONNABORTED;
-			break;
-		}
+		if (server_unresponsive(server))
+			return -ECONNABORTED;
 
-		segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);
+		length = sock_recvmsg(server->ssocket, smb_msg, 0);
 
-		length = kernel_recvmsg(server->ssocket, &smb_msg,
-					iov, segs, to_read, 0);
+		if (server->tcpStatus == CifsExiting)
+			return -ESHUTDOWN;
 
-		if (server->tcpStatus == CifsExiting) {
-			total_read = -ESHUTDOWN;
-			break;
-		} else if (server->tcpStatus == CifsNeedReconnect) {
+		if (server->tcpStatus == CifsNeedReconnect) {
 			cifs_reconnect(server);
-			total_read = -ECONNABORTED;
-			break;
-		} else if (length == -ERESTARTSYS ||
-			   length == -EAGAIN ||
-			   length == -EINTR) {
+			return -ECONNABORTED;
+		}
+
+		if (length == -ERESTARTSYS ||
+		    length == -EAGAIN ||
+		    length == -EINTR) {
 			/*
 			 * Minimum sleep to prevent looping, allowing socket
 			 * to clear and app threads to set tcpStatus
@@ -602,12 +537,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
 			usleep_range(1000, 2000);
 			length = 0;
 			continue;
-		} else if (length <= 0) {
-			cifs_dbg(FYI, "Received no data or error: expecting %d\n"
-				 "got %d", to_read, length);
+		}
+
+		if (length <= 0) {
+			cifs_dbg(FYI, "Received no data or error: %d\n", length);
 			cifs_reconnect(server);
-			total_read = -ECONNABORTED;
-			break;
+			return -ECONNABORTED;
 		}
 	}
 	return total_read;
@@ -617,12 +552,21 @@ int
 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 		      unsigned int to_read)
 {
-	struct kvec iov;
+	struct msghdr smb_msg;
+	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
+	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
 
-	iov.iov_base = buf;
-	iov.iov_len = to_read;
+	return cifs_readv_from_socket(server, &smb_msg);
+}
 
-	return cifs_readv_from_socket(server, &iov, 1, to_read);
+int
+cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
+		      unsigned int to_read)
+{
+	struct msghdr smb_msg;
+	struct bio_vec bv = {.bv_page = page, .bv_len = to_read};
+	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
+	return cifs_readv_from_socket(server, &smb_msg);
 }
 
 static bool
@@ -783,7 +727,6 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
 	}
 
 	kfree(server->hostname);
-	kfree(server->iov);
 	kfree(server);
 
 	length = atomic_dec_return(&tcpSesAllocCount);