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

8 files changed, 167 insertions, 383 deletions

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 4897dacf8944..6aeb8d4616a4 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -66,45 +66,15 @@ cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
 	return 0;
 }
 
-/*
- * Calculate and return the CIFS signature based on the mac key and SMB PDU.
- * The 16 byte signature must be allocated by the caller. Note we only use the
- * 1st eight bytes and that the smb header signature field on input contains
- * the sequence number before this function is called. Also, this function
- * should be called with the server->srv_mutex held.
- */
-static int cifs_calc_signature(struct smb_rqst *rqst,
-			struct TCP_Server_Info *server, char *signature)
+int __cifs_calc_signature(struct smb_rqst *rqst,
+			struct TCP_Server_Info *server, char *signature,
+			struct shash_desc *shash)
 {
 	int i;
 	int rc;
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
 
-	if (iov == NULL || signature == NULL || server == NULL)
-		return -EINVAL;
-
-	if (!server->secmech.sdescmd5) {
-		rc = cifs_crypto_shash_md5_allocate(server);
-		if (rc) {
-			cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
-			return -1;
-		}
-	}
-
-	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
-	if (rc) {
-		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
-		return rc;
-	}
-
-	rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
-		server->session_key.response, server->session_key.len);
-	if (rc) {
-		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
-		return rc;
-	}
-
 	for (i = 0; i < n_vec; i++) {
 		if (iov[i].iov_len == 0)
 			continue;
@@ -117,12 +87,10 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
 		if (i == 0) {
 			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 				break; /* nothing to sign or corrupt header */
-			rc =
-			crypto_shash_update(&server->secmech.sdescmd5->shash,
+			rc = crypto_shash_update(shash,
 				iov[i].iov_base + 4, iov[i].iov_len - 4);
 		} else {
-			rc =
-			crypto_shash_update(&server->secmech.sdescmd5->shash,
+			rc = crypto_shash_update(shash,
 				iov[i].iov_base, iov[i].iov_len);
 		}
 		if (rc) {
@@ -134,21 +102,64 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
 
 	/* now hash over the rq_pages array */
 	for (i = 0; i < rqst->rq_npages; i++) {
-		struct kvec p_iov;
+		void *kaddr = kmap(rqst->rq_pages[i]);
+		size_t len = rqst->rq_pagesz;
+
+		if (i == rqst->rq_npages - 1)
+			len = rqst->rq_tailsz;
+
+		crypto_shash_update(shash, kaddr, len);
 
-		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-		crypto_shash_update(&server->secmech.sdescmd5->shash,
-					p_iov.iov_base, p_iov.iov_len);
 		kunmap(rqst->rq_pages[i]);
 	}
 
-	rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
+	rc = crypto_shash_final(shash, signature);
 	if (rc)
-		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
+		cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
 
 	return rc;
 }
 
+/*
+ * Calculate and return the CIFS signature based on the mac key and SMB PDU.
+ * The 16 byte signature must be allocated by the caller. Note we only use the
+ * 1st eight bytes and that the smb header signature field on input contains
+ * the sequence number before this function is called. Also, this function
+ * should be called with the server->srv_mutex held.
+ */
+static int cifs_calc_signature(struct smb_rqst *rqst,
+			struct TCP_Server_Info *server, char *signature)
+{
+	int rc;
+
+	if (!rqst->rq_iov || !signature || !server)
+		return -EINVAL;
+
+	if (!server->secmech.sdescmd5) {
+		rc = cifs_crypto_shash_md5_allocate(server);
+		if (rc) {
+			cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
+			return -1;
+		}
+	}
+
+	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+	if (rc) {
+		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
+		return rc;
+	}
+
+	rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
+		server->session_key.response, server->session_key.len);
+	if (rc) {
+		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
+		return rc;
+	}
+
+	return __cifs_calc_signature(rqst, server, signature,
+				     &server->secmech.sdescmd5->shash);
+}
+
 /* must be called with server->srv_mutex held */
 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 		   __u32 *pexpected_response_sequence_number)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index f2cc0b3d1af7..bba106cdc43c 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -615,8 +615,6 @@ struct TCP_Server_Info {
 	bool	sec_mskerberos;		/* supports legacy MS Kerberos */
 	bool	large_buf;		/* is current buffer large? */
 	struct delayed_work	echo; /* echo ping workqueue job */
-	struct kvec *iov;	/* reusable kvec array for receives */
-	unsigned int nr_iov;	/* number of kvecs in array */
 	char	*smallbuf;	/* pointer to current "small" buffer */
 	char	*bigbuf;	/* pointer to current "big" buffer */
 	unsigned int total_read; /* total amount of data read in this pass */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index eed7ff50faf0..0f9a6bc4ba43 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -37,8 +37,6 @@ extern void cifs_buf_release(void *);
 extern struct smb_hdr *cifs_small_buf_get(void);
 extern void cifs_small_buf_release(void *);
 extern void free_rsp_buf(int, void *);
-extern void cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
-					struct kvec *iov);
 extern int smb_send(struct TCP_Server_Info *, struct smb_hdr *,
 			unsigned int /* length */);
 extern unsigned int _get_xid(void);
@@ -181,10 +179,9 @@ extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 
 extern void dequeue_mid(struct mid_q_entry *mid, bool malformed);
 extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
-		     unsigned int to_read);
-extern int cifs_readv_from_socket(struct TCP_Server_Info *server,
-		struct kvec *iov_orig, unsigned int nr_segs,
-		unsigned int to_read);
+			         unsigned int to_read);
+extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
+				      struct page *page, unsigned int to_read);
 extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 			       struct cifs_sb_info *cifs_sb);
 extern int cifs_match_super(struct super_block *, void *);
@@ -512,4 +509,7 @@ int cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 			   struct cifs_sb_info *cifs_sb,
 			   const unsigned char *path, char *pbuf,
 			   unsigned int *pbytes_written);
+int __cifs_calc_signature(struct smb_rqst *rqst,
+			struct TCP_Server_Info *server, char *signature,
+			struct shash_desc *shash);
 #endif			/* _CIFSPROTO_H */
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 145c03e75ee4..d47197ea4ab6 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1447,10 +1447,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	len = min_t(unsigned int, buflen, server->vals->read_rsp_size) -
 							HEADER_SIZE(server) + 1;
 
-	rdata->iov.iov_base = buf + HEADER_SIZE(server) - 1;
-	rdata->iov.iov_len = len;
-
-	length = cifs_readv_from_socket(server, &rdata->iov, 1, len);
+	length = cifs_read_from_socket(server,
+				       buf + HEADER_SIZE(server) - 1, len);
 	if (length < 0)
 		return length;
 	server->total_read += length;
@@ -1502,9 +1500,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	len = data_offset - server->total_read;
 	if (len > 0) {
 		/* read any junk before data into the rest of smallbuf */
-		rdata->iov.iov_base = buf + server->total_read;
-		rdata->iov.iov_len = len;
-		length = cifs_readv_from_socket(server, &rdata->iov, 1, len);
+		length = cifs_read_from_socket(server,
+					       buf + server->total_read, len);
 		if (length < 0)
 			return length;
 		server->total_read += length;
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);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index f3a90298dfe2..9793ae0bcaa2 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2852,39 +2852,31 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
 	int result = 0;
 	unsigned int i;
 	unsigned int nr_pages = rdata->nr_pages;
-	struct kvec iov;
 
 	rdata->got_bytes = 0;
 	rdata->tailsz = PAGE_SIZE;
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = rdata->pages[i];
+		size_t n;
 
-		if (len >= PAGE_SIZE) {
-			/* enough data to fill the page */
-			iov.iov_base = kmap(page);
-			iov.iov_len = PAGE_SIZE;
-			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
-				 i, iov.iov_base, iov.iov_len);
-			len -= PAGE_SIZE;
-		} else if (len > 0) {
-			/* enough for partial page, fill and zero the rest */
-			iov.iov_base = kmap(page);
-			iov.iov_len = len;
-			cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
-				 i, iov.iov_base, iov.iov_len);
-			memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
-			rdata->tailsz = len;
-			len = 0;
-		} else {
+		if (len <= 0) {
 			/* no need to hold page hostage */
 			rdata->pages[i] = NULL;
 			rdata->nr_pages--;
 			put_page(page);
 			continue;
 		}
-
-		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
-		kunmap(page);
+		n = len;
+		if (len >= PAGE_SIZE) {
+			/* enough data to fill the page */
+			n = PAGE_SIZE;
+			len -= n;
+		} else {
+			zero_user(page, len, PAGE_SIZE - len);
+			rdata->tailsz = len;
+			len = 0;
+		}
+		result = cifs_read_page_from_socket(server, page, n);
 		if (result < 0)
 			break;
 
@@ -3300,7 +3292,6 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 	u64 eof;
 	pgoff_t eof_index;
 	unsigned int nr_pages = rdata->nr_pages;
-	struct kvec iov;
 
 	/* determine the eof that the server (probably) has */
 	eof = CIFS_I(rdata->mapping->host)->server_eof;
@@ -3311,23 +3302,14 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 	rdata->tailsz = PAGE_SIZE;
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = rdata->pages[i];
+		size_t n = PAGE_SIZE;
 
 		if (len >= PAGE_SIZE) {
-			/* enough data to fill the page */
-			iov.iov_base = kmap(page);
-			iov.iov_len = PAGE_SIZE;
-			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
-				 i, page->index, iov.iov_base, iov.iov_len);
 			len -= PAGE_SIZE;
 		} else if (len > 0) {
 			/* enough for partial page, fill and zero the rest */
-			iov.iov_base = kmap(page);
-			iov.iov_len = len;
-			cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
-				 i, page->index, iov.iov_base, iov.iov_len);
-			memset(iov.iov_base + len,
-				'\0', PAGE_SIZE - len);
-			rdata->tailsz = len;
+			zero_user(page, len, PAGE_SIZE - len);
+			n = rdata->tailsz = len;
 			len = 0;
 		} else if (page->index > eof_index) {
 			/*
@@ -3357,8 +3339,7 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
 			continue;
 		}
 
-		result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
-		kunmap(page);
+		result = cifs_read_page_from_socket(server, page, n);
 		if (result < 0)
 			break;
 
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 8732a43b1008..bc9a7b634643 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -135,11 +135,10 @@ smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
 int
 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
-	int i, rc;
+	int rc;
 	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 	unsigned char *sigptr = smb2_signature;
 	struct kvec *iov = rqst->rq_iov;
-	int n_vec = rqst->rq_nvec;
 	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 	struct cifs_ses *ses;
 
@@ -171,53 +170,11 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 		return rc;
 	}
 
-	for (i = 0; i < n_vec; i++) {
-		if (iov[i].iov_len == 0)
-			continue;
-		if (iov[i].iov_base == NULL) {
-			cifs_dbg(VFS, "null iovec entry\n");
-			return -EIO;
-		}
-		/*
-		 * The first entry includes a length field (which does not get
-		 * signed that occupies the first 4 bytes before the header).
-		 */
-		if (i == 0) {
-			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
-				break; /* nothing to sign or corrupt header */
-			rc =
-			crypto_shash_update(
-				&server->secmech.sdeschmacsha256->shash,
-				iov[i].iov_base + 4, iov[i].iov_len - 4);
-		} else {
-			rc =
-			crypto_shash_update(
-				&server->secmech.sdeschmacsha256->shash,
-				iov[i].iov_base, iov[i].iov_len);
-		}
-		if (rc) {
-			cifs_dbg(VFS, "%s: Could not update with payload\n",
-				 __func__);
-			return rc;
-		}
-	}
-
-	/* now hash over the rq_pages array */
-	for (i = 0; i < rqst->rq_npages; i++) {
-		struct kvec p_iov;
-
-		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-		crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
-					p_iov.iov_base, p_iov.iov_len);
-		kunmap(rqst->rq_pages[i]);
-	}
-
-	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
-				sigptr);
-	if (rc)
-		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
+	rc = __cifs_calc_signature(rqst, server, sigptr,
+		&server->secmech.sdeschmacsha256->shash);
 
-	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+	if (!rc)
+		memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 
 	return rc;
 }
@@ -395,12 +352,10 @@ generate_smb311signingkey(struct cifs_ses *ses)
 int
 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
-	int i;
 	int rc = 0;
 	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 	unsigned char *sigptr = smb3_signature;
 	struct kvec *iov = rqst->rq_iov;
-	int n_vec = rqst->rq_nvec;
 	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 	struct cifs_ses *ses;
 
@@ -431,54 +386,12 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 		cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 		return rc;
 	}
+	
+	rc = __cifs_calc_signature(rqst, server, sigptr,
+				   &server->secmech.sdesccmacaes->shash);
 
-	for (i = 0; i < n_vec; i++) {
-		if (iov[i].iov_len == 0)
-			continue;
-		if (iov[i].iov_base == NULL) {
-			cifs_dbg(VFS, "null iovec entry");
-			return -EIO;
-		}
-		/*
-		 * The first entry includes a length field (which does not get
-		 * signed that occupies the first 4 bytes before the header).
-		 */
-		if (i == 0) {
-			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
-				break; /* nothing to sign or corrupt header */
-			rc =
-			crypto_shash_update(
-				&server->secmech.sdesccmacaes->shash,
-				iov[i].iov_base + 4, iov[i].iov_len - 4);
-		} else {
-			rc =
-			crypto_shash_update(
-				&server->secmech.sdesccmacaes->shash,
-				iov[i].iov_base, iov[i].iov_len);
-		}
-		if (rc) {
-			cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
-							__func__);
-			return rc;
-		}
-	}
-
-	/* now hash over the rq_pages array */
-	for (i = 0; i < rqst->rq_npages; i++) {
-		struct kvec p_iov;
-
-		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-		crypto_shash_update(&server->secmech.sdesccmacaes->shash,
-					p_iov.iov_base, p_iov.iov_len);
-		kunmap(rqst->rq_pages[i]);
-	}
-
-	rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
-						sigptr);
-	if (rc)
-		cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);
-
-	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+	if (!rc)
+		memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 
 	return rc;
 }
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 87abe8ed074c..206a597b2293 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -124,41 +124,32 @@ cifs_delete_mid(struct mid_q_entry *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
+ * @smb_msg:	Message to send
  * @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_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
-		size_t *sent)
+smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
+	      size_t *sent)
 {
 	int rc = 0;
-	int i = 0;
-	struct msghdr smb_msg;
-	unsigned int remaining;
-	size_t first_vec = 0;
+	int retries = 0;
 	struct socket *ssocket = server->ssocket;
 
 	*sent = 0;
 
-	smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
-	smb_msg.msg_namelen = sizeof(struct sockaddr);
-	smb_msg.msg_control = NULL;
-	smb_msg.msg_controllen = 0;
+	smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
+	smb_msg->msg_namelen = sizeof(struct sockaddr);
+	smb_msg->msg_control = NULL;
+	smb_msg->msg_controllen = 0;
 	if (server->noblocksnd)
-		smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
+		smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 	else
-		smb_msg.msg_flags = MSG_NOSIGNAL;
-
-	remaining = 0;
-	for (i = 0; i < n_vec; i++)
-		remaining += iov[i].iov_len;
+		smb_msg->msg_flags = MSG_NOSIGNAL;
 
-	i = 0;
-	while (remaining) {
+	while (msg_data_left(smb_msg)) {
 		/*
 		 * If blocking send, we try 3 times, since each can block
 		 * for 5 seconds. For nonblocking  we have to try more
@@ -177,35 +168,21 @@ smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
 		 * 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, remaining);
+		rc = sock_sendmsg(ssocket, smb_msg);
 		if (rc == -EAGAIN) {
-			i++;
-			if (i >= 14 || (!server->noblocksnd && (i > 2))) {
+			retries++;
+			if (retries >= 14 ||
+			    (!server->noblocksnd && (retries > 2))) {
 				cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
 					 ssocket);
-				rc = -EAGAIN;
-				break;
+				return -EAGAIN;
 			}
-			msleep(1 << i);
+			msleep(1 << retries);
 			continue;
 		}
 
 		if (rc < 0)
-			break;
-
-		/* send was at least partially successful */
-		*sent += rc;
-
-		if (rc == remaining) {
-			remaining = 0;
-			break;
-		}
-
-		if (rc > remaining) {
-			cifs_dbg(VFS, "sent %d requested %d\n", rc, remaining);
-			break;
-		}
+			return rc;
 
 		if (rc == 0) {
 			/* should never happen, letting socket clear before
@@ -215,59 +192,11 @@ smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
 			continue;
 		}
 
-		remaining -= rc;
-
-		/* the line below resets i */
-		for (i = first_vec; i < n_vec; i++) {
-			if (iov[i].iov_len) {
-				if (rc > iov[i].iov_len) {
-					rc -= iov[i].iov_len;
-					iov[i].iov_len = 0;
-				} else {
-					iov[i].iov_base += rc;
-					iov[i].iov_len -= rc;
-					first_vec = i;
-					break;
-				}
-			}
-		}
-
-		i = 0; /* in case we get ENOSPC on the next send */
-		rc = 0;
+		/* send was at least partially successful */
+		*sent += rc;
+		retries = 0; /* in case we get ENOSPC on the next send */
 	}
-	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;
+	return 0;
 }
 
 static unsigned long
@@ -299,8 +228,9 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
 	unsigned long send_length;
 	unsigned int i;
-	size_t total_len = 0, sent;
+	size_t total_len = 0, sent, size;
 	struct socket *ssocket = server->ssocket;
+	struct msghdr smb_msg;
 	int val = 1;
 
 	if (ssocket == NULL)
@@ -321,7 +251,13 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
 				(char *)&val, sizeof(val));
 
-	rc = smb_send_kvec(server, iov, n_vec, &sent);
+	size = 0;
+	for (i = 0; i < n_vec; i++)
+		size += iov[i].iov_len;
+
+	iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, iov, n_vec, size);
+
+	rc = smb_send_kvec(server, &smb_msg, &sent);
 	if (rc < 0)
 		goto uncork;
 
@@ -329,11 +265,16 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 
 	/* 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]);
+		size_t len = i == rqst->rq_npages - 1
+				? rqst->rq_tailsz
+				: rqst->rq_pagesz;
+		struct bio_vec bvec = {
+			.bv_page = rqst->rq_pages[i],
+			.bv_len = len
+		};
+		iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
+			      &bvec, 1, len);
+		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
 			break;