Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5774 insertions, 0 deletions

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
new file mode 100644
index 000000000..e65f998ea
--- /dev/null
+++ b/fs/smb/client/smb2pdu.c
@@ -0,0 +1,5774 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ *
+ *   Copyright (C) International Business Machines  Corp., 2009, 2013
+ *                 Etersoft, 2012
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *              Pavel Shilovsky (pshilovsky@samba.org) 2012
+ *
+ *   Contains the routines for constructing the SMB2 PDUs themselves
+ *
+ */
+
+ /* SMB2 PDU handling routines here - except for leftovers (eg session setup) */
+ /* Note that there are handle based routines which must be		      */
+ /* treated slightly differently for reconnection purposes since we never     */
+ /* want to reuse a stale file handle and only the caller knows the file info */
+
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/vfs.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/uaccess.h>
+#include <linux/uuid.h>
+#include <linux/pagemap.h>
+#include <linux/xattr.h>
+#include "cifsglob.h"
+#include "cifsacl.h"
+#include "cifsproto.h"
+#include "smb2proto.h"
+#include "cifs_unicode.h"
+#include "cifs_debug.h"
+#include "ntlmssp.h"
+#include "smb2status.h"
+#include "smb2glob.h"
+#include "cifspdu.h"
+#include "cifs_spnego.h"
+#include "smbdirect.h"
+#include "trace.h"
+#ifdef CONFIG_CIFS_DFS_UPCALL
+#include "dfs_cache.h"
+#endif
+#include "cached_dir.h"
+
+/*
+ *  The following table defines the expected "StructureSize" of SMB2 requests
+ *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS requests.
+ *
+ *  Note that commands are defined in smb2pdu.h in le16 but the array below is
+ *  indexed by command in host byte order.
+ */
+static const int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
+	/* SMB2_NEGOTIATE */ 36,
+	/* SMB2_SESSION_SETUP */ 25,
+	/* SMB2_LOGOFF */ 4,
+	/* SMB2_TREE_CONNECT */	9,
+	/* SMB2_TREE_DISCONNECT */ 4,
+	/* SMB2_CREATE */ 57,
+	/* SMB2_CLOSE */ 24,
+	/* SMB2_FLUSH */ 24,
+	/* SMB2_READ */	49,
+	/* SMB2_WRITE */ 49,
+	/* SMB2_LOCK */	48,
+	/* SMB2_IOCTL */ 57,
+	/* SMB2_CANCEL */ 4,
+	/* SMB2_ECHO */ 4,
+	/* SMB2_QUERY_DIRECTORY */ 33,
+	/* SMB2_CHANGE_NOTIFY */ 32,
+	/* SMB2_QUERY_INFO */ 41,
+	/* SMB2_SET_INFO */ 33,
+	/* SMB2_OPLOCK_BREAK */ 24 /* BB this is 36 for LEASE_BREAK variant */
+};
+
+int smb3_encryption_required(const struct cifs_tcon *tcon)
+{
+	if (!tcon || !tcon->ses)
+		return 0;
+	if ((tcon->ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA) ||
+	    (tcon->share_flags & SHI1005_FLAGS_ENCRYPT_DATA))
+		return 1;
+	if (tcon->seal &&
+	    (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
+		return 1;
+	return 0;
+}
+
+static void
+smb2_hdr_assemble(struct smb2_hdr *shdr, __le16 smb2_cmd,
+		  const struct cifs_tcon *tcon,
+		  struct TCP_Server_Info *server)
+{
+	struct smb3_hdr_req *smb3_hdr;
+	shdr->ProtocolId = SMB2_PROTO_NUMBER;
+	shdr->StructureSize = cpu_to_le16(64);
+	shdr->Command = smb2_cmd;
+	if (server->dialect >= SMB30_PROT_ID) {
+		/* After reconnect SMB3 must set ChannelSequence on subsequent reqs */
+		smb3_hdr = (struct smb3_hdr_req *)shdr;
+		/* if primary channel is not set yet, use default channel for chan sequence num */
+		if (CIFS_SERVER_IS_CHAN(server))
+			smb3_hdr->ChannelSequence =
+				cpu_to_le16(server->primary_server->channel_sequence_num);
+		else
+			smb3_hdr->ChannelSequence = cpu_to_le16(server->channel_sequence_num);
+	}
+	if (server) {
+		spin_lock(&server->req_lock);
+		/* Request up to 10 credits but don't go over the limit. */
+		if (server->credits >= server->max_credits)
+			shdr->CreditRequest = cpu_to_le16(0);
+		else
+			shdr->CreditRequest = cpu_to_le16(
+				min_t(int, server->max_credits -
+						server->credits, 10));
+		spin_unlock(&server->req_lock);
+	} else {
+		shdr->CreditRequest = cpu_to_le16(2);
+	}
+	shdr->Id.SyncId.ProcessId = cpu_to_le32((__u16)current->tgid);
+
+	if (!tcon)
+		goto out;
+
+	/* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */
+	/* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */
+	if (server && (server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
+		shdr->CreditCharge = cpu_to_le16(1);
+	/* else CreditCharge MBZ */
+
+	shdr->Id.SyncId.TreeId = cpu_to_le32(tcon->tid);
+	/* Uid is not converted */
+	if (tcon->ses)
+		shdr->SessionId = cpu_to_le64(tcon->ses->Suid);
+
+	/*
+	 * If we would set SMB2_FLAGS_DFS_OPERATIONS on open we also would have
+	 * to pass the path on the Open SMB prefixed by \\server\share.
+	 * Not sure when we would need to do the augmented path (if ever) and
+	 * setting this flag breaks the SMB2 open operation since it is
+	 * illegal to send an empty path name (without \\server\share prefix)
+	 * when the DFS flag is set in the SMB open header. We could
+	 * consider setting the flag on all operations other than open
+	 * but it is safer to net set it for now.
+	 */
+/*	if (tcon->share_flags & SHI1005_FLAGS_DFS)
+		shdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS; */
+
+	if (server && server->sign && !smb3_encryption_required(tcon))
+		shdr->Flags |= SMB2_FLAGS_SIGNED;
+out:
+	return;
+}
+
+static int
+smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
+	       struct TCP_Server_Info *server)
+{
+	int rc = 0;
+	struct nls_table *nls_codepage = NULL;
+	struct cifs_ses *ses;
+
+	/*
+	 * SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
+	 * check for tcp and smb session status done differently
+	 * for those three - in the calling routine.
+	 */
+	if (tcon == NULL)
+		return 0;
+
+	/*
+	 * Need to also skip SMB2_IOCTL because it is used for checking nested dfs links in
+	 * cifs_tree_connect().
+	 */
+	if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL)
+		return 0;
+
+	spin_lock(&tcon->tc_lock);
+	if (tcon->status == TID_EXITING) {
+		/*
+		 * only tree disconnect allowed when disconnecting ...
+		 */
+		if (smb2_command != SMB2_TREE_DISCONNECT) {
+			spin_unlock(&tcon->tc_lock);
+			cifs_dbg(FYI, "can not send cmd %d while umounting\n",
+				 smb2_command);
+			return -ENODEV;
+		}
+	}
+	spin_unlock(&tcon->tc_lock);
+
+	ses = tcon->ses;
+	if (!ses)
+		return -EIO;
+	spin_lock(&ses->ses_lock);
+	if (ses->ses_status == SES_EXITING) {
+		spin_unlock(&ses->ses_lock);
+		return -EIO;
+	}
+	spin_unlock(&ses->ses_lock);
+	if (!ses->server || !server)
+		return -EIO;
+
+	spin_lock(&server->srv_lock);
+	if (server->tcpStatus == CifsNeedReconnect) {
+		/*
+		 * Return to caller for TREE_DISCONNECT and LOGOFF and CLOSE
+		 * here since they are implicitly done when session drops.
+		 */
+		switch (smb2_command) {
+		/*
+		 * BB Should we keep oplock break and add flush to exceptions?
+		 */
+		case SMB2_TREE_DISCONNECT:
+		case SMB2_CANCEL:
+		case SMB2_CLOSE:
+		case SMB2_OPLOCK_BREAK:
+			spin_unlock(&server->srv_lock);
+			return -EAGAIN;
+		}
+	}
+	spin_unlock(&server->srv_lock);
+
+again:
+	rc = cifs_wait_for_server_reconnect(server, tcon->retry);
+	if (rc)
+		return rc;
+
+	spin_lock(&ses->chan_lock);
+	if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) {
+		spin_unlock(&ses->chan_lock);
+		return 0;
+	}
+	spin_unlock(&ses->chan_lock);
+	cifs_dbg(FYI, "sess reconnect mask: 0x%lx, tcon reconnect: %d",
+		 tcon->ses->chans_need_reconnect,
+		 tcon->need_reconnect);
+
+	mutex_lock(&ses->session_mutex);
+	/*
+	 * Recheck after acquire mutex. If another thread is negotiating
+	 * and the server never sends an answer the socket will be closed
+	 * and tcpStatus set to reconnect.
+	 */
+	spin_lock(&server->srv_lock);
+	if (server->tcpStatus == CifsNeedReconnect) {
+		spin_unlock(&server->srv_lock);
+		mutex_unlock(&ses->session_mutex);
+
+		if (tcon->retry)
+			goto again;
+
+		rc = -EHOSTDOWN;
+		goto out;
+	}
+	spin_unlock(&server->srv_lock);
+
+	nls_codepage = load_nls_default();
+
+	/*
+	 * need to prevent multiple threads trying to simultaneously
+	 * reconnect the same SMB session
+	 */
+	spin_lock(&ses->ses_lock);
+	spin_lock(&ses->chan_lock);
+	if (!cifs_chan_needs_reconnect(ses, server) &&
+	    ses->ses_status == SES_GOOD) {
+		spin_unlock(&ses->chan_lock);
+		spin_unlock(&ses->ses_lock);
+		/* this means that we only need to tree connect */
+		if (tcon->need_reconnect)
+			goto skip_sess_setup;
+
+		mutex_unlock(&ses->session_mutex);
+		goto out;
+	}
+	spin_unlock(&ses->chan_lock);
+	spin_unlock(&ses->ses_lock);
+
+	rc = cifs_negotiate_protocol(0, ses, server);
+	if (!rc) {
+		rc = cifs_setup_session(0, ses, server, nls_codepage);
+		if ((rc == -EACCES) && !tcon->retry) {
+			mutex_unlock(&ses->session_mutex);
+			rc = -EHOSTDOWN;
+			goto failed;
+		} else if (rc) {
+			mutex_unlock(&ses->session_mutex);
+			goto out;
+		}
+	} else {
+		mutex_unlock(&ses->session_mutex);
+		goto out;
+	}
+
+skip_sess_setup:
+	if (!tcon->need_reconnect) {
+		mutex_unlock(&ses->session_mutex);
+		goto out;
+	}
+	cifs_mark_open_files_invalid(tcon);
+	if (tcon->use_persistent)
+		tcon->need_reopen_files = true;
+
+	rc = cifs_tree_connect(0, tcon, nls_codepage);
+	mutex_unlock(&ses->session_mutex);
+
+	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
+	if (rc) {
+		/* If sess reconnected but tcon didn't, something strange ... */
+		cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
+		goto out;
+	}
+
+	if (smb2_command != SMB2_INTERNAL_CMD)
+		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
+
+	atomic_inc(&tconInfoReconnectCount);
+out:
+	/*
+	 * Check if handle based operation so we know whether we can continue
+	 * or not without returning to caller to reset file handle.
+	 */
+	/*
+	 * BB Is flush done by server on drop of tcp session? Should we special
+	 * case it and skip above?
+	 */
+	switch (smb2_command) {
+	case SMB2_FLUSH:
+	case SMB2_READ:
+	case SMB2_WRITE:
+	case SMB2_LOCK:
+	case SMB2_IOCTL:
+	case SMB2_QUERY_DIRECTORY:
+	case SMB2_CHANGE_NOTIFY:
+	case SMB2_QUERY_INFO:
+	case SMB2_SET_INFO:
+		rc = -EAGAIN;
+	}
+failed:
+	unload_nls(nls_codepage);
+	return rc;
+}
+
+static void
+fill_small_buf(__le16 smb2_command, struct cifs_tcon *tcon,
+	       struct TCP_Server_Info *server,
+	       void *buf,
+	       unsigned int *total_len)
+{
+	struct smb2_pdu *spdu = buf;
+	/* lookup word count ie StructureSize from table */
+	__u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_command)];
+
+	/*
+	 * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
+	 * largest operations (Create)
+	 */
+	memset(buf, 0, 256);
+
+	smb2_hdr_assemble(&spdu->hdr, smb2_command, tcon, server);
+	spdu->StructureSize2 = cpu_to_le16(parmsize);
+
+	*total_len = parmsize + sizeof(struct smb2_hdr);
+}
+
+/*
+ * Allocate and return pointer to an SMB request hdr, and set basic
+ * SMB information in the SMB header. If the return code is zero, this
+ * function must have filled in request_buf pointer.
+ */
+static int __smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
+				 struct TCP_Server_Info *server,
+				 void **request_buf, unsigned int *total_len)
+{
+	/* BB eventually switch this to SMB2 specific small buf size */
+	switch (smb2_command) {
+	case SMB2_SET_INFO:
+	case SMB2_QUERY_INFO:
+		*request_buf = cifs_buf_get();
+		break;
+	default:
+		*request_buf = cifs_small_buf_get();
+		break;
+	}
+	if (*request_buf == NULL) {
+		/* BB should we add a retry in here if not a writepage? */
+		return -ENOMEM;
+	}
+
+	fill_small_buf(smb2_command, tcon, server,
+		       (struct smb2_hdr *)(*request_buf),
+		       total_len);
+
+	if (tcon != NULL) {
+		uint16_t com_code = le16_to_cpu(smb2_command);
+		cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_sent[com_code]);
+		cifs_stats_inc(&tcon->num_smbs_sent);
+	}
+
+	return 0;
+}
+
+static int smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
+			       struct TCP_Server_Info *server,
+			       void **request_buf, unsigned int *total_len)
+{
+	int rc;
+
+	rc = smb2_reconnect(smb2_command, tcon, server);
+	if (rc)
+		return rc;
+
+	return __smb2_plain_req_init(smb2_command, tcon, server, request_buf,
+				     total_len);
+}
+
+static int smb2_ioctl_req_init(u32 opcode, struct cifs_tcon *tcon,
+			       struct TCP_Server_Info *server,
+			       void **request_buf, unsigned int *total_len)
+{
+	/* Skip reconnect only for FSCTL_VALIDATE_NEGOTIATE_INFO IOCTLs */
+	if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO) {
+		return __smb2_plain_req_init(SMB2_IOCTL, tcon, server,
+					     request_buf, total_len);
+	}
+	return smb2_plain_req_init(SMB2_IOCTL, tcon, server,
+				   request_buf, total_len);
+}
+
+/* For explanation of negotiate contexts see MS-SMB2 section 2.2.3.1 */
+
+static void
+build_preauth_ctxt(struct smb2_preauth_neg_context *pneg_ctxt)
+{
+	pneg_ctxt->ContextType = SMB2_PREAUTH_INTEGRITY_CAPABILITIES;
+	pneg_ctxt->DataLength = cpu_to_le16(38);
+	pneg_ctxt->HashAlgorithmCount = cpu_to_le16(1);
+	pneg_ctxt->SaltLength = cpu_to_le16(SMB311_SALT_SIZE);
+	get_random_bytes(pneg_ctxt->Salt, SMB311_SALT_SIZE);
+	pneg_ctxt->HashAlgorithms = SMB2_PREAUTH_INTEGRITY_SHA512;
+}
+
+static void
+build_compression_ctxt(struct smb2_compression_capabilities_context *pneg_ctxt)
+{
+	pneg_ctxt->ContextType = SMB2_COMPRESSION_CAPABILITIES;
+	pneg_ctxt->DataLength =
+		cpu_to_le16(sizeof(struct smb2_compression_capabilities_context)
+			  - sizeof(struct smb2_neg_context));
+	pneg_ctxt->CompressionAlgorithmCount = cpu_to_le16(3);
+	pneg_ctxt->CompressionAlgorithms[0] = SMB3_COMPRESS_LZ77;
+	pneg_ctxt->CompressionAlgorithms[1] = SMB3_COMPRESS_LZ77_HUFF;
+	pneg_ctxt->CompressionAlgorithms[2] = SMB3_COMPRESS_LZNT1;
+}
+
+static unsigned int
+build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt)
+{
+	unsigned int ctxt_len = sizeof(struct smb2_signing_capabilities);
+	unsigned short num_algs = 1; /* number of signing algorithms sent */
+
+	pneg_ctxt->ContextType = SMB2_SIGNING_CAPABILITIES;
+	/*
+	 * Context Data length must be rounded to multiple of 8 for some servers
+	 */
+	pneg_ctxt->DataLength = cpu_to_le16(ALIGN(sizeof(struct smb2_signing_capabilities) -
+					    sizeof(struct smb2_neg_context) +
+					    (num_algs * sizeof(u16)), 8));
+	pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs);
+	pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC);
+
+	ctxt_len += sizeof(__le16) * num_algs;
+	ctxt_len = ALIGN(ctxt_len, 8);
+	return ctxt_len;
+	/* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */
+}
+
+static void
+build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
+{
+	pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
+	if (require_gcm_256) {
+		pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + 1 cipher */
+		pneg_ctxt->CipherCount = cpu_to_le16(1);
+		pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES256_GCM;
+	} else if (enable_gcm_256) {
+		pneg_ctxt->DataLength = cpu_to_le16(8); /* Cipher Count + 3 ciphers */
+		pneg_ctxt->CipherCount = cpu_to_le16(3);
+		pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
+		pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES256_GCM;
+		pneg_ctxt->Ciphers[2] = SMB2_ENCRYPTION_AES128_CCM;
+	} else {
+		pneg_ctxt->DataLength = cpu_to_le16(6); /* Cipher Count + 2 ciphers */
+		pneg_ctxt->CipherCount = cpu_to_le16(2);
+		pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
+		pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM;
+	}
+}
+
+static unsigned int
+build_netname_ctxt(struct smb2_netname_neg_context *pneg_ctxt, char *hostname)
+{
+	struct nls_table *cp = load_nls_default();
+
+	pneg_ctxt->ContextType = SMB2_NETNAME_NEGOTIATE_CONTEXT_ID;
+
+	/* copy up to max of first 100 bytes of server name to NetName field */
+	pneg_ctxt->DataLength = cpu_to_le16(2 * cifs_strtoUTF16(pneg_ctxt->NetName, hostname, 100, cp));
+	/* context size is DataLength + minimal smb2_neg_context */
+	return ALIGN(le16_to_cpu(pneg_ctxt->DataLength) + sizeof(struct smb2_neg_context), 8);
+}
+
+static void
+build_posix_ctxt(struct smb2_posix_neg_context *pneg_ctxt)
+{
+	pneg_ctxt->ContextType = SMB2_POSIX_EXTENSIONS_AVAILABLE;
+	pneg_ctxt->DataLength = cpu_to_le16(POSIX_CTXT_DATA_LEN);
+	/* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
+	pneg_ctxt->Name[0] = 0x93;
+	pneg_ctxt->Name[1] = 0xAD;
+	pneg_ctxt->Name[2] = 0x25;
+	pneg_ctxt->Name[3] = 0x50;
+	pneg_ctxt->Name[4] = 0x9C;
+	pneg_ctxt->Name[5] = 0xB4;
+	pneg_ctxt->Name[6] = 0x11;
+	pneg_ctxt->Name[7] = 0xE7;
+	pneg_ctxt->Name[8] = 0xB4;
+	pneg_ctxt->Name[9] = 0x23;
+	pneg_ctxt->Name[10] = 0x83;
+	pneg_ctxt->Name[11] = 0xDE;
+	pneg_ctxt->Name[12] = 0x96;
+	pneg_ctxt->Name[13] = 0x8B;
+	pneg_ctxt->Name[14] = 0xCD;
+	pneg_ctxt->Name[15] = 0x7C;
+}
+
+static void
+assemble_neg_contexts(struct smb2_negotiate_req *req,
+		      struct TCP_Server_Info *server, unsigned int *total_len)
+{
+	unsigned int ctxt_len, neg_context_count;
+	struct TCP_Server_Info *pserver;
+	char *pneg_ctxt;
+	char *hostname;
+
+	if (*total_len > 200) {
+		/* In case length corrupted don't want to overrun smb buffer */
+		cifs_server_dbg(VFS, "Bad frame length assembling neg contexts\n");
+		return;
+	}
+
+	/*
+	 * round up total_len of fixed part of SMB3 negotiate request to 8
+	 * byte boundary before adding negotiate contexts
+	 */
+	*total_len = ALIGN(*total_len, 8);
+
+	pneg_ctxt = (*total_len) + (char *)req;
+	req->NegotiateContextOffset = cpu_to_le32(*total_len);
+
+	build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
+	ctxt_len = ALIGN(sizeof(struct smb2_preauth_neg_context), 8);
+	*total_len += ctxt_len;
+	pneg_ctxt += ctxt_len;
+
+	build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt);
+	ctxt_len = ALIGN(sizeof(struct smb2_encryption_neg_context), 8);
+	*total_len += ctxt_len;
+	pneg_ctxt += ctxt_len;
+
+	/*
+	 * secondary channels don't have the hostname field populated
+	 * use the hostname field in the primary channel instead
+	 */
+	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
+	cifs_server_lock(pserver);
+	hostname = pserver->hostname;
+	if (hostname && (hostname[0] != 0)) {
+		ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
+					      hostname);
+		*total_len += ctxt_len;
+		pneg_ctxt += ctxt_len;
+		neg_context_count = 3;
+	} else
+		neg_context_count = 2;
+	cifs_server_unlock(pserver);
+
+	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
+	*total_len += sizeof(struct smb2_posix_neg_context);
+	pneg_ctxt += sizeof(struct smb2_posix_neg_context);
+	neg_context_count++;
+
+	if (server->compress_algorithm) {
+		build_compression_ctxt((struct smb2_compression_capabilities_context *)
+				pneg_ctxt);
+		ctxt_len = ALIGN(sizeof(struct smb2_compression_capabilities_context), 8);
+		*total_len += ctxt_len;
+		pneg_ctxt += ctxt_len;
+		neg_context_count++;
+	}
+
+	if (enable_negotiate_signing) {
+		ctxt_len = build_signing_ctxt((struct smb2_signing_capabilities *)
+				pneg_ctxt);
+		*total_len += ctxt_len;
+		pneg_ctxt += ctxt_len;
+		neg_context_count++;
+	}
+
+	/* check for and add transport_capabilities and signing capabilities */
+	req->NegotiateContextCount = cpu_to_le16(neg_context_count);
+
+}
+
+/* If invalid preauth context warn but use what we requested, SHA-512 */
+static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
+{
+	unsigned int len = le16_to_cpu(ctxt->DataLength);
+
+	/*
+	 * Caller checked that DataLength remains within SMB boundary. We still
+	 * need to confirm that one HashAlgorithms member is accounted for.
+	 */
+	if (len < MIN_PREAUTH_CTXT_DATA_LEN) {
+		pr_warn_once("server sent bad preauth context\n");
+		return;
+	} else if (len < MIN_PREAUTH_CTXT_DATA_LEN + le16_to_cpu(ctxt->SaltLength)) {
+		pr_warn_once("server sent invalid SaltLength\n");
+		return;
+	}
+	if (le16_to_cpu(ctxt->HashAlgorithmCount) != 1)
+		pr_warn_once("Invalid SMB3 hash algorithm count\n");
+	if (ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
+		pr_warn_once("unknown SMB3 hash algorithm\n");
+}
+
+static void decode_compress_ctx(struct TCP_Server_Info *server,
+			 struct smb2_compression_capabilities_context *ctxt)
+{
+	unsigned int len = le16_to_cpu(ctxt->DataLength);
+
+	/*
+	 * Caller checked that DataLength remains within SMB boundary. We still
+	 * need to confirm that one CompressionAlgorithms member is accounted
+	 * for.
+	 */
+	if (len < 10) {
+		pr_warn_once("server sent bad compression cntxt\n");
+		return;
+	}
+	if (le16_to_cpu(ctxt->CompressionAlgorithmCount) != 1) {
+		pr_warn_once("Invalid SMB3 compress algorithm count\n");
+		return;
+	}
+	if (le16_to_cpu(ctxt->CompressionAlgorithms[0]) > 3) {
+		pr_warn_once("unknown compression algorithm\n");
+		return;
+	}
+	server->compress_algorithm = ctxt->CompressionAlgorithms[0];
+}
+
+static int decode_encrypt_ctx(struct TCP_Server_Info *server,
+			      struct smb2_encryption_neg_context *ctxt)
+{
+	unsigned int len = le16_to_cpu(ctxt->DataLength);
+
+	cifs_dbg(FYI, "decode SMB3.11 encryption neg context of len %d\n", len);
+	/*
+	 * Caller checked that DataLength remains within SMB boundary. We still
+	 * need to confirm that one Cipher flexible array member is accounted
+	 * for.
+	 */
+	if (len < MIN_ENCRYPT_CTXT_DATA_LEN) {
+		pr_warn_once("server sent bad crypto ctxt len\n");
+		return -EINVAL;
+	}
+
+	if (le16_to_cpu(ctxt->CipherCount) != 1) {
+		pr_warn_once("Invalid SMB3.11 cipher count\n");
+		return -EINVAL;
+	}
+	cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0]));
+	if (require_gcm_256) {
+		if (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM) {
+			cifs_dbg(VFS, "Server does not support requested encryption type (AES256 GCM)\n");
+			return -EOPNOTSUPP;
+		}
+	} else if (ctxt->Ciphers[0] == 0) {
+		/*
+		 * e.g. if server only supported AES256_CCM (very unlikely)
+		 * or server supported no encryption types or had all disabled.
+		 * Since GLOBAL_CAP_ENCRYPTION will be not set, in the case
+		 * in which mount requested encryption ("seal") checks later
+		 * on during tree connection will return proper rc, but if
+		 * seal not requested by client, since server is allowed to
+		 * return 0 to indicate no supported cipher, we can't fail here
+		 */
+		server->cipher_type = 0;
+		server->capabilities &= ~SMB2_GLOBAL_CAP_ENCRYPTION;
+		pr_warn_once("Server does not support requested encryption types\n");
+		return 0;
+	} else if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) &&
+		   (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM) &&
+		   (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM)) {
+		/* server returned a cipher we didn't ask for */
+		pr_warn_once("Invalid SMB3.11 cipher returned\n");
+		return -EINVAL;
+	}
+	server->cipher_type = ctxt->Ciphers[0];
+	server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
+	return 0;
+}
+
+static void decode_signing_ctx(struct TCP_Server_Info *server,
+			       struct smb2_signing_capabilities *pctxt)
+{
+	unsigned int len = le16_to_cpu(pctxt->DataLength);
+
+	/*
+	 * Caller checked that DataLength remains within SMB boundary. We still
+	 * need to confirm that one SigningAlgorithms flexible array member is
+	 * accounted for.
+	 */
+	if ((len < 4) || (len > 16)) {
+		pr_warn_once("server sent bad signing negcontext\n");
+		return;
+	}
+	if (le16_to_cpu(pctxt->SigningAlgorithmCount) != 1) {
+		pr_warn_once("Invalid signing algorithm count\n");
+		return;
+	}
+	if (le16_to_cpu(pctxt->SigningAlgorithms[0]) > 2) {
+		pr_warn_once("unknown signing algorithm\n");
+		return;
+	}
+
+	server->signing_negotiated = true;
+	server->signing_algorithm = le16_to_cpu(pctxt->SigningAlgorithms[0]);
+	cifs_dbg(FYI, "signing algorithm %d chosen\n",
+		     server->signing_algorithm);
+}
+
+
+static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
+				     struct TCP_Server_Info *server,
+				     unsigned int len_of_smb)
+{
+	struct smb2_neg_context *pctx;
+	unsigned int offset = le32_to_cpu(rsp->NegotiateContextOffset);
+	unsigned int ctxt_cnt = le16_to_cpu(rsp->NegotiateContextCount);
+	unsigned int len_of_ctxts, i;
+	int rc = 0;
+
+	cifs_dbg(FYI, "decoding %d negotiate contexts\n", ctxt_cnt);
+	if (len_of_smb <= offset) {
+		cifs_server_dbg(VFS, "Invalid response: negotiate context offset\n");
+		return -EINVAL;
+	}
+
+	len_of_ctxts = len_of_smb - offset;
+
+	for (i = 0; i < ctxt_cnt; i++) {
+		int clen;
+		/* check that offset is not beyond end of SMB */
+		if (len_of_ctxts < sizeof(struct smb2_neg_context))
+			break;
+
+		pctx = (struct smb2_neg_context *)(offset + (char *)rsp);
+		clen = sizeof(struct smb2_neg_context)
+			+ le16_to_cpu(pctx->DataLength);
+		/*
+		 * 2.2.4 SMB2 NEGOTIATE Response
+		 * Subsequent negotiate contexts MUST appear at the first 8-byte
+		 * aligned offset following the previous negotiate context.
+		 */
+		if (i + 1 != ctxt_cnt)
+			clen = ALIGN(clen, 8);
+		if (clen > len_of_ctxts)
+			break;
+
+		if (pctx->ContextType == SMB2_PREAUTH_INTEGRITY_CAPABILITIES)
+			decode_preauth_context(
+				(struct smb2_preauth_neg_context *)pctx);
+		else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES)
+			rc = decode_encrypt_ctx(server,
+				(struct smb2_encryption_neg_context *)pctx);
+		else if (pctx->ContextType == SMB2_COMPRESSION_CAPABILITIES)
+			decode_compress_ctx(server,
+				(struct smb2_compression_capabilities_context *)pctx);
+		else if (pctx->ContextType == SMB2_POSIX_EXTENSIONS_AVAILABLE)
+			server->posix_ext_supported = true;
+		else if (pctx->ContextType == SMB2_SIGNING_CAPABILITIES)
+			decode_signing_ctx(server,
+				(struct smb2_signing_capabilities *)pctx);
+		else
+			cifs_server_dbg(VFS, "unknown negcontext of type %d ignored\n",
+				le16_to_cpu(pctx->ContextType));
+		if (rc)
+			break;
+
+		offset += clen;
+		len_of_ctxts -= clen;
+	}
+	return rc;
+}
+
+static struct create_posix *
+create_posix_buf(umode_t mode)
+{
+	struct create_posix *buf;
+
+	buf = kzalloc(sizeof(struct create_posix),
+			GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset =
+		cpu_to_le16(offsetof(struct create_posix, Mode));
+	buf->ccontext.DataLength = cpu_to_le32(4);
+	buf->ccontext.NameOffset =
+		cpu_to_le16(offsetof(struct create_posix, Name));
+	buf->ccontext.NameLength = cpu_to_le16(16);
+
+	/* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
+	buf->Name[0] = 0x93;
+	buf->Name[1] = 0xAD;
+	buf->Name[2] = 0x25;
+	buf->Name[3] = 0x50;
+	buf->Name[4] = 0x9C;
+	buf->Name[5] = 0xB4;
+	buf->Name[6] = 0x11;
+	buf->Name[7] = 0xE7;
+	buf->Name[8] = 0xB4;
+	buf->Name[9] = 0x23;
+	buf->Name[10] = 0x83;
+	buf->Name[11] = 0xDE;
+	buf->Name[12] = 0x96;
+	buf->Name[13] = 0x8B;
+	buf->Name[14] = 0xCD;
+	buf->Name[15] = 0x7C;
+	buf->Mode = cpu_to_le32(mode);
+	cifs_dbg(FYI, "mode on posix create 0%o\n", mode);
+	return buf;
+}
+
+static int
+add_posix_context(struct kvec *iov, unsigned int *num_iovec, umode_t mode)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	iov[num].iov_base = create_posix_buf(mode);
+	if (mode == ACL_NO_MODE)
+		cifs_dbg(FYI, "Invalid mode\n");
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct create_posix);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset = cpu_to_le32(
+				sizeof(struct smb2_create_req) +
+				iov[num - 1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_posix));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+
+/*
+ *
+ *	SMB2 Worker functions follow:
+ *
+ *	The general structure of the worker functions is:
+ *	1) Call smb2_init (assembles SMB2 header)
+ *	2) Initialize SMB2 command specific fields in fixed length area of SMB
+ *	3) Call smb_sendrcv2 (sends request on socket and waits for response)
+ *	4) Decode SMB2 command specific fields in the fixed length area
+ *	5) Decode variable length data area (if any for this SMB2 command type)
+ *	6) Call free smb buffer
+ *	7) return
+ *
+ */
+
+int
+SMB2_negotiate(const unsigned int xid,
+	       struct cifs_ses *ses,
+	       struct TCP_Server_Info *server)
+{
+	struct smb_rqst rqst;
+	struct smb2_negotiate_req *req;
+	struct smb2_negotiate_rsp *rsp;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int rc;
+	int resp_buftype;
+	int blob_offset, blob_length;
+	char *security_blob;
+	int flags = CIFS_NEG_OP;
+	unsigned int total_len;
+
+	cifs_dbg(FYI, "Negotiate protocol\n");
+
+	if (!server) {
+		WARN(1, "%s: server is NULL!\n", __func__);
+		return -EIO;
+	}
+
+	rc = smb2_plain_req_init(SMB2_NEGOTIATE, NULL, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->hdr.SessionId = 0;
+
+	memset(server->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE);
+	memset(ses->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE);
+
+	if (strcmp(server->vals->version_string,
+		   SMB3ANY_VERSION_STRING) == 0) {
+		req->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
+		req->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
+		req->Dialects[2] = cpu_to_le16(SMB311_PROT_ID);
+		req->DialectCount = cpu_to_le16(3);
+		total_len += 6;
+	} else if (strcmp(server->vals->version_string,
+		   SMBDEFAULT_VERSION_STRING) == 0) {
+		req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
+		req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
+		req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
+		req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
+		req->DialectCount = cpu_to_le16(4);
+		total_len += 8;
+	} else {
+		/* otherwise send specific dialect */
+		req->Dialects[0] = cpu_to_le16(server->vals->protocol_id);
+		req->DialectCount = cpu_to_le16(1);
+		total_len += 2;
+	}
+
+	/* only one of SMB2 signing flags may be set in SMB2 request */
+	if (ses->sign)
+		req->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
+	else if (global_secflags & CIFSSEC_MAY_SIGN)
+		req->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
+	else
+		req->SecurityMode = 0;
+
+	req->Capabilities = cpu_to_le32(server->vals->req_capabilities);
+	if (ses->chan_max > 1)
+		req->Capabilities |= cpu_to_le32(SMB2_GLOBAL_CAP_MULTI_CHANNEL);
+
+	/* ClientGUID must be zero for SMB2.02 dialect */
+	if (server->vals->protocol_id == SMB20_PROT_ID)
+		memset(req->ClientGUID, 0, SMB2_CLIENT_GUID_SIZE);
+	else {
+		memcpy(req->ClientGUID, server->client_guid,
+			SMB2_CLIENT_GUID_SIZE);
+		if ((server->vals->protocol_id == SMB311_PROT_ID) ||
+		    (strcmp(server->vals->version_string,
+		     SMB3ANY_VERSION_STRING) == 0) ||
+		    (strcmp(server->vals->version_string,
+		     SMBDEFAULT_VERSION_STRING) == 0))
+			assemble_neg_contexts(req, server, &total_len);
+	}
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+	rsp = (struct smb2_negotiate_rsp *)rsp_iov.iov_base;
+	/*
+	 * No tcon so can't do
+	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
+	 */
+	if (rc == -EOPNOTSUPP) {
+		cifs_server_dbg(VFS, "Dialect not supported by server. Consider  specifying vers=1.0 or vers=2.0 on mount for accessing older servers\n");
+		goto neg_exit;
+	} else if (rc != 0)
+		goto neg_exit;
+
+	rc = -EIO;
+	if (strcmp(server->vals->version_string,
+		   SMB3ANY_VERSION_STRING) == 0) {
+		if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
+			cifs_server_dbg(VFS,
+				"SMB2 dialect returned but not requested\n");
+			goto neg_exit;
+		} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
+			cifs_server_dbg(VFS,
+				"SMB2.1 dialect returned but not requested\n");
+			goto neg_exit;
+		} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
+			/* ops set to 3.0 by default for default so update */
+			server->ops = &smb311_operations;
+			server->vals = &smb311_values;
+		}
+	} else if (strcmp(server->vals->version_string,
+		   SMBDEFAULT_VERSION_STRING) == 0) {
+		if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
+			cifs_server_dbg(VFS,
+				"SMB2 dialect returned but not requested\n");
+			goto neg_exit;
+		} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
+			/* ops set to 3.0 by default for default so update */
+			server->ops = &smb21_operations;
+			server->vals = &smb21_values;
+		} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
+			server->ops = &smb311_operations;
+			server->vals = &smb311_values;
+		}
+	} else if (le16_to_cpu(rsp->DialectRevision) !=
+				server->vals->protocol_id) {
+		/* if requested single dialect ensure returned dialect matched */
+		cifs_server_dbg(VFS, "Invalid 0x%x dialect returned: not requested\n",
+				le16_to_cpu(rsp->DialectRevision));
+		goto neg_exit;
+	}
+
+	cifs_dbg(FYI, "mode 0x%x\n", rsp->SecurityMode);
+
+	if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb2.0 dialect\n");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb2.1 dialect\n");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB30_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb3.0 dialect\n");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB302_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb3.02 dialect\n");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb3.1.1 dialect\n");
+	else {
+		cifs_server_dbg(VFS, "Invalid dialect returned by server 0x%x\n",
+				le16_to_cpu(rsp->DialectRevision));
+		goto neg_exit;
+	}
+
+	rc = 0;
+	server->dialect = le16_to_cpu(rsp->DialectRevision);
+
+	/*
+	 * Keep a copy of the hash after negprot. This hash will be
+	 * the starting hash value for all sessions made from this
+	 * server.
+	 */
+	memcpy(server->preauth_sha_hash, ses->preauth_sha_hash,
+	       SMB2_PREAUTH_HASH_SIZE);
+
+	/* SMB2 only has an extended negflavor */
+	server->negflavor = CIFS_NEGFLAVOR_EXTENDED;
+	/* set it to the maximum buffer size value we can send with 1 credit */
+	server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
+			       SMB2_MAX_BUFFER_SIZE);
+	server->max_read = le32_to_cpu(rsp->MaxReadSize);
+	server->max_write = le32_to_cpu(rsp->MaxWriteSize);
+	server->sec_mode = le16_to_cpu(rsp->SecurityMode);
+	if ((server->sec_mode & SMB2_SEC_MODE_FLAGS_ALL) != server->sec_mode)
+		cifs_dbg(FYI, "Server returned unexpected security mode 0x%x\n",
+				server->sec_mode);
+	server->capabilities = le32_to_cpu(rsp->Capabilities);
+	/* Internal types */
+	server->capabilities |= SMB2_NT_FIND | SMB2_LARGE_FILES;
+
+	/*
+	 * SMB3.0 supports only 1 cipher and doesn't have a encryption neg context
+	 * Set the cipher type manually.
+	 */
+	if (server->dialect == SMB30_PROT_ID && (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
+		server->cipher_type = SMB2_ENCRYPTION_AES128_CCM;
+
+	security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
+					       (struct smb2_hdr *)rsp);
+	/*
+	 * See MS-SMB2 section 2.2.4: if no blob, client picks default which
+	 * for us will be
+	 *	ses->sectype = RawNTLMSSP;
+	 * but for time being this is our only auth choice so doesn't matter.
+	 * We just found a server which sets blob length to zero expecting raw.
+	 */
+	if (blob_length == 0) {
+		cifs_dbg(FYI, "missing security blob on negprot\n");
+		server->sec_ntlmssp = true;
+	}
+
+	rc = cifs_enable_signing(server, ses->sign);
+	if (rc)
+		goto neg_exit;
+	if (blob_length) {
+		rc = decode_negTokenInit(security_blob, blob_length, server);
+		if (rc == 1)
+			rc = 0;
+		else if (rc == 0)
+			rc = -EIO;
+	}
+
+	if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
+		if (rsp->NegotiateContextCount)
+			rc = smb311_decode_neg_context(rsp, server,
+						       rsp_iov.iov_len);
+		else
+			cifs_server_dbg(VFS, "Missing expected negotiate contexts\n");
+	}
+neg_exit:
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
+{
+	int rc;
+	struct validate_negotiate_info_req *pneg_inbuf;
+	struct validate_negotiate_info_rsp *pneg_rsp = NULL;
+	u32 rsplen;
+	u32 inbuflen; /* max of 4 dialects */
+	struct TCP_Server_Info *server = tcon->ses->server;
+
+	cifs_dbg(FYI, "validate negotiate\n");
+
+	/* In SMB3.11 preauth integrity supersedes validate negotiate */
+	if (server->dialect == SMB311_PROT_ID)
+		return 0;
+
+	/*
+	 * validation ioctl must be signed, so no point sending this if we
+	 * can not sign it (ie are not known user).  Even if signing is not
+	 * required (enabled but not negotiated), in those cases we selectively
+	 * sign just this, the first and only signed request on a connection.
+	 * Having validation of negotiate info  helps reduce attack vectors.
+	 */
+	if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_GUEST)
+		return 0; /* validation requires signing */
+
+	if (tcon->ses->user_name == NULL) {
+		cifs_dbg(FYI, "Can't validate negotiate: null user mount\n");
+		return 0; /* validation requires signing */
+	}
+
+	if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL)
+		cifs_tcon_dbg(VFS, "Unexpected null user (anonymous) auth flag sent by server\n");
+
+	pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_NOFS);
+	if (!pneg_inbuf)
+		return -ENOMEM;
+
+	pneg_inbuf->Capabilities =
+			cpu_to_le32(server->vals->req_capabilities);
+	if (tcon->ses->chan_max > 1)
+		pneg_inbuf->Capabilities |= cpu_to_le32(SMB2_GLOBAL_CAP_MULTI_CHANNEL);
+
+	memcpy(pneg_inbuf->Guid, server->client_guid,
+					SMB2_CLIENT_GUID_SIZE);
+
+	if (tcon->ses->sign)
+		pneg_inbuf->SecurityMode =
+			cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
+	else if (global_secflags & CIFSSEC_MAY_SIGN)
+		pneg_inbuf->SecurityMode =
+			cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
+	else
+		pneg_inbuf->SecurityMode = 0;
+
+
+	if (strcmp(server->vals->version_string,
+		SMB3ANY_VERSION_STRING) == 0) {
+		pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
+		pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
+		pneg_inbuf->Dialects[2] = cpu_to_le16(SMB311_PROT_ID);
+		pneg_inbuf->DialectCount = cpu_to_le16(3);
+		/* SMB 2.1 not included so subtract one dialect from len */
+		inbuflen = sizeof(*pneg_inbuf) -
+				(sizeof(pneg_inbuf->Dialects[0]));
+	} else if (strcmp(server->vals->version_string,
+		SMBDEFAULT_VERSION_STRING) == 0) {
+		pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
+		pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
+		pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
+		pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
+		pneg_inbuf->DialectCount = cpu_to_le16(4);
+		/* structure is big enough for 4 dialects */
+		inbuflen = sizeof(*pneg_inbuf);
+	} else {
+		/* otherwise specific dialect was requested */
+		pneg_inbuf->Dialects[0] =
+			cpu_to_le16(server->vals->protocol_id);
+		pneg_inbuf->DialectCount = cpu_to_le16(1);
+		/* structure is big enough for 4 dialects, sending only 1 */
+		inbuflen = sizeof(*pneg_inbuf) -
+				sizeof(pneg_inbuf->Dialects[0]) * 3;
+	}
+
+	rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
+		FSCTL_VALIDATE_NEGOTIATE_INFO,
+		(char *)pneg_inbuf, inbuflen, CIFSMaxBufSize,
+		(char **)&pneg_rsp, &rsplen);
+	if (rc == -EOPNOTSUPP) {
+		/*
+		 * Old Windows versions or Netapp SMB server can return
+		 * not supported error. Client should accept it.
+		 */
+		cifs_tcon_dbg(VFS, "Server does not support validate negotiate\n");
+		rc = 0;
+		goto out_free_inbuf;
+	} else if (rc != 0) {
+		cifs_tcon_dbg(VFS, "validate protocol negotiate failed: %d\n",
+			      rc);
+		rc = -EIO;
+		goto out_free_inbuf;
+	}
+
+	rc = -EIO;
+	if (rsplen != sizeof(*pneg_rsp)) {
+		cifs_tcon_dbg(VFS, "Invalid protocol negotiate response size: %d\n",
+			      rsplen);
+
+		/* relax check since Mac returns max bufsize allowed on ioctl */
+		if (rsplen > CIFSMaxBufSize || rsplen < sizeof(*pneg_rsp))
+			goto out_free_rsp;
+	}
+
+	/* check validate negotiate info response matches what we got earlier */
+	if (pneg_rsp->Dialect != cpu_to_le16(server->dialect))
+		goto vneg_out;
+
+	if (pneg_rsp->SecurityMode != cpu_to_le16(server->sec_mode))
+		goto vneg_out;
+
+	/* do not validate server guid because not saved at negprot time yet */
+
+	if ((le32_to_cpu(pneg_rsp->Capabilities) | SMB2_NT_FIND |
+	      SMB2_LARGE_FILES) != server->capabilities)
+		goto vneg_out;
+
+	/* validate negotiate successful */
+	rc = 0;
+	cifs_dbg(FYI, "validate negotiate info successful\n");
+	goto out_free_rsp;
+
+vneg_out:
+	cifs_tcon_dbg(VFS, "protocol revalidation - security settings mismatch\n");
+out_free_rsp:
+	kfree(pneg_rsp);
+out_free_inbuf:
+	kfree(pneg_inbuf);
+	return rc;
+}
+
+enum securityEnum
+smb2_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
+{
+	switch (requested) {
+	case Kerberos:
+	case RawNTLMSSP:
+		return requested;
+	case NTLMv2:
+		return RawNTLMSSP;
+	case Unspecified:
+		if (server->sec_ntlmssp &&
+			(global_secflags & CIFSSEC_MAY_NTLMSSP))
+			return RawNTLMSSP;
+		if ((server->sec_kerberos || server->sec_mskerberos) &&
+			(global_secflags & CIFSSEC_MAY_KRB5))
+			return Kerberos;
+		fallthrough;
+	default:
+		return Unspecified;
+	}
+}
+
+struct SMB2_sess_data {
+	unsigned int xid;
+	struct cifs_ses *ses;
+	struct TCP_Server_Info *server;
+	struct nls_table *nls_cp;
+	void (*func)(struct SMB2_sess_data *);
+	int result;
+	u64 previous_session;
+
+	/* we will send the SMB in three pieces:
+	 * a fixed length beginning part, an optional
+	 * SPNEGO blob (which can be zero length), and a
+	 * last part which will include the strings
+	 * and rest of bcc area. This allows us to avoid
+	 * a large buffer 17K allocation
+	 */
+	int buf0_type;
+	struct kvec iov[2];
+};
+
+static int
+SMB2_sess_alloc_buffer(struct SMB2_sess_data *sess_data)
+{
+	int rc;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+	struct smb2_sess_setup_req *req;
+	unsigned int total_len;
+	bool is_binding = false;
+
+	rc = smb2_plain_req_init(SMB2_SESSION_SETUP, NULL, server,
+				 (void **) &req,
+				 &total_len);
+	if (rc)
+		return rc;
+
+	spin_lock(&ses->ses_lock);
+	is_binding = (ses->ses_status == SES_GOOD);
+	spin_unlock(&ses->ses_lock);
+
+	if (is_binding) {
+		req->hdr.SessionId = cpu_to_le64(ses->Suid);
+		req->hdr.Flags |= SMB2_FLAGS_SIGNED;
+		req->PreviousSessionId = 0;
+		req->Flags = SMB2_SESSION_REQ_FLAG_BINDING;
+		cifs_dbg(FYI, "Binding to sess id: %llx\n", ses->Suid);
+	} else {
+		/* First session, not a reauthenticate */
+		req->hdr.SessionId = 0;
+		/*
+		 * if reconnect, we need to send previous sess id
+		 * otherwise it is 0
+		 */
+		req->PreviousSessionId = cpu_to_le64(sess_data->previous_session);
+		req->Flags = 0; /* MBZ */
+		cifs_dbg(FYI, "Fresh session. Previous: %llx\n",
+			 sess_data->previous_session);
+	}
+
+	/* enough to enable echos and oplocks and one max size write */
+	if (server->credits >= server->max_credits)
+		req->hdr.CreditRequest = cpu_to_le16(0);
+	else
+		req->hdr.CreditRequest = cpu_to_le16(
+			min_t(int, server->max_credits -
+			      server->credits, 130));
+
+	/* only one of SMB2 signing flags may be set in SMB2 request */
+	if (server->sign)
+		req->SecurityMode = SMB2_NEGOTIATE_SIGNING_REQUIRED;
+	else if (global_secflags & CIFSSEC_MAY_SIGN) /* one flag unlike MUST_ */
+		req->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED;
+	else
+		req->SecurityMode = 0;
+
+#ifdef CONFIG_CIFS_DFS_UPCALL
+	req->Capabilities = cpu_to_le32(SMB2_GLOBAL_CAP_DFS);
+#else
+	req->Capabilities = 0;
+#endif /* DFS_UPCALL */
+
+	req->Channel = 0; /* MBZ */
+
+	sess_data->iov[0].iov_base = (char *)req;
+	/* 1 for pad */
+	sess_data->iov[0].iov_len = total_len - 1;
+	/*
+	 * This variable will be used to clear the buffer
+	 * allocated above in case of any error in the calling function.
+	 */
+	sess_data->buf0_type = CIFS_SMALL_BUFFER;
+
+	return 0;
+}
+
+static void
+SMB2_sess_free_buffer(struct SMB2_sess_data *sess_data)
+{
+	struct kvec *iov = sess_data->iov;
+
+	/* iov[1] is already freed by caller */
+	if (sess_data->buf0_type != CIFS_NO_BUFFER && iov[0].iov_base)
+		memzero_explicit(iov[0].iov_base, iov[0].iov_len);
+
+	free_rsp_buf(sess_data->buf0_type, iov[0].iov_base);
+	sess_data->buf0_type = CIFS_NO_BUFFER;
+}
+
+static int
+SMB2_sess_sendreceive(struct SMB2_sess_data *sess_data)
+{
+	int rc;
+	struct smb_rqst rqst;
+	struct smb2_sess_setup_req *req = sess_data->iov[0].iov_base;
+	struct kvec rsp_iov = { NULL, 0 };
+
+	/* Testing shows that buffer offset must be at location of Buffer[0] */
+	req->SecurityBufferOffset =
+		cpu_to_le16(sizeof(struct smb2_sess_setup_req));
+	req->SecurityBufferLength = cpu_to_le16(sess_data->iov[1].iov_len);
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = sess_data->iov;
+	rqst.rq_nvec = 2;
+
+	/* BB add code to build os and lm fields */
+	rc = cifs_send_recv(sess_data->xid, sess_data->ses,
+			    sess_data->server,
+			    &rqst,
+			    &sess_data->buf0_type,
+			    CIFS_LOG_ERROR | CIFS_SESS_OP, &rsp_iov);
+	cifs_small_buf_release(sess_data->iov[0].iov_base);
+	memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
+
+	return rc;
+}
+
+static int
+SMB2_sess_establish_session(struct SMB2_sess_data *sess_data)
+{
+	int rc = 0;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+
+	cifs_server_lock(server);
+	if (server->ops->generate_signingkey) {
+		rc = server->ops->generate_signingkey(ses, server);
+		if (rc) {
+			cifs_dbg(FYI,
+				"SMB3 session key generation failed\n");
+			cifs_server_unlock(server);
+			return rc;
+		}
+	}
+	if (!server->session_estab) {
+		server->sequence_number = 0x2;
+		server->session_estab = true;
+	}
+	cifs_server_unlock(server);
+
+	cifs_dbg(FYI, "SMB2/3 session established successfully\n");
+	return rc;
+}
+
+#ifdef CONFIG_CIFS_UPCALL
+static void
+SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
+{
+	int rc;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+	struct cifs_spnego_msg *msg;
+	struct key *spnego_key = NULL;
+	struct smb2_sess_setup_rsp *rsp = NULL;
+	bool is_binding = false;
+
+	rc = SMB2_sess_alloc_buffer(sess_data);
+	if (rc)
+		goto out;
+
+	spnego_key = cifs_get_spnego_key(ses, server);
+	if (IS_ERR(spnego_key)) {
+		rc = PTR_ERR(spnego_key);
+		if (rc == -ENOKEY)
+			cifs_dbg(VFS, "Verify user has a krb5 ticket and keyutils is installed\n");
+		spnego_key = NULL;
+		goto out;
+	}
+
+	msg = spnego_key->payload.data[0];
+	/*
+	 * check version field to make sure that cifs.upcall is
+	 * sending us a response in an expected form
+	 */
+	if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
+		cifs_dbg(VFS, "bad cifs.upcall version. Expected %d got %d\n",
+			 CIFS_SPNEGO_UPCALL_VERSION, msg->version);
+		rc = -EKEYREJECTED;
+		goto out_put_spnego_key;
+	}
+
+	spin_lock(&ses->ses_lock);
+	is_binding = (ses->ses_status == SES_GOOD);
+	spin_unlock(&ses->ses_lock);
+
+	/* keep session key if binding */
+	if (!is_binding) {
+		kfree_sensitive(ses->auth_key.response);
+		ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
+						 GFP_KERNEL);
+		if (!ses->auth_key.response) {
+			cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
+				 msg->sesskey_len);
+			rc = -ENOMEM;
+			goto out_put_spnego_key;
+		}
+		ses->auth_key.len = msg->sesskey_len;
+	}
+
+	sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
+	sess_data->iov[1].iov_len = msg->secblob_len;
+
+	rc = SMB2_sess_sendreceive(sess_data);
+	if (rc)
+		goto out_put_spnego_key;
+
+	rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base;
+	/* keep session id and flags if binding */
+	if (!is_binding) {
+		ses->Suid = le64_to_cpu(rsp->hdr.SessionId);
+		ses->session_flags = le16_to_cpu(rsp->SessionFlags);
+	}
+
+	rc = SMB2_sess_establish_session(sess_data);
+out_put_spnego_key:
+	key_invalidate(spnego_key);
+	key_put(spnego_key);
+	if (rc) {
+		kfree_sensitive(ses->auth_key.response);
+		ses->auth_key.response = NULL;
+		ses->auth_key.len = 0;
+	}
+out:
+	sess_data->result = rc;
+	sess_data->func = NULL;
+	SMB2_sess_free_buffer(sess_data);
+}
+#else
+static void
+SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
+{
+	cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
+	sess_data->result = -EOPNOTSUPP;
+	sess_data->func = NULL;
+}
+#endif
+
+static void
+SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data);
+
+static void
+SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data)
+{
+	int rc;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+	struct smb2_sess_setup_rsp *rsp = NULL;
+	unsigned char *ntlmssp_blob = NULL;
+	bool use_spnego = false; /* else use raw ntlmssp */
+	u16 blob_length = 0;
+	bool is_binding = false;
+
+	/*
+	 * If memory allocation is successful, caller of this function
+	 * frees it.
+	 */
+	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
+	if (!ses->ntlmssp) {
+		rc = -ENOMEM;
+		goto out_err;
+	}
+	ses->ntlmssp->sesskey_per_smbsess = true;
+
+	rc = SMB2_sess_alloc_buffer(sess_data);
+	if (rc)
+		goto out_err;
+
+	rc = build_ntlmssp_smb3_negotiate_blob(&ntlmssp_blob,
+					  &blob_length, ses, server,
+					  sess_data->nls_cp);
+	if (rc)
+		goto out;
+
+	if (use_spnego) {
+		/* BB eventually need to add this */
+		cifs_dbg(VFS, "spnego not supported for SMB2 yet\n");
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+	sess_data->iov[1].iov_base = ntlmssp_blob;
+	sess_data->iov[1].iov_len = blob_length;
+
+	rc = SMB2_sess_sendreceive(sess_data);
+	rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base;
+
+	/* If true, rc here is expected and not an error */
+	if (sess_data->buf0_type != CIFS_NO_BUFFER &&
+		rsp->hdr.Status == STATUS_MORE_PROCESSING_REQUIRED)
+		rc = 0;
+
+	if (rc)
+		goto out;
+
+	if (offsetof(struct smb2_sess_setup_rsp, Buffer) !=
+			le16_to_cpu(rsp->SecurityBufferOffset)) {
+		cifs_dbg(VFS, "Invalid security buffer offset %d\n",
+			le16_to_cpu(rsp->SecurityBufferOffset));
+		rc = -EIO;
+		goto out;
+	}
+	rc = decode_ntlmssp_challenge(rsp->Buffer,
+			le16_to_cpu(rsp->SecurityBufferLength), ses);
+	if (rc)
+		goto out;
+
+	cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
+
+	spin_lock(&ses->ses_lock);
+	is_binding = (ses->ses_status == SES_GOOD);
+	spin_unlock(&ses->ses_lock);
+
+	/* keep existing ses id and flags if binding */
+	if (!is_binding) {
+		ses->Suid = le64_to_cpu(rsp->hdr.SessionId);
+		ses->session_flags = le16_to_cpu(rsp->SessionFlags);
+	}
+
+out:
+	kfree_sensitive(ntlmssp_blob);
+	SMB2_sess_free_buffer(sess_data);
+	if (!rc) {
+		sess_data->result = 0;
+		sess_data->func = SMB2_sess_auth_rawntlmssp_authenticate;
+		return;
+	}
+out_err:
+	kfree_sensitive(ses->ntlmssp);
+	ses->ntlmssp = NULL;
+	sess_data->result = rc;
+	sess_data->func = NULL;
+}
+
+static void
+SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data)
+{
+	int rc;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+	struct smb2_sess_setup_req *req;
+	struct smb2_sess_setup_rsp *rsp = NULL;
+	unsigned char *ntlmssp_blob = NULL;
+	bool use_spnego = false; /* else use raw ntlmssp */
+	u16 blob_length = 0;
+	bool is_binding = false;
+
+	rc = SMB2_sess_alloc_buffer(sess_data);
+	if (rc)
+		goto out;
+
+	req = (struct smb2_sess_setup_req *) sess_data->iov[0].iov_base;
+	req->hdr.SessionId = cpu_to_le64(ses->Suid);
+
+	rc = build_ntlmssp_auth_blob(&ntlmssp_blob, &blob_length,
+				     ses, server,
+				     sess_data->nls_cp);
+	if (rc) {
+		cifs_dbg(FYI, "build_ntlmssp_auth_blob failed %d\n", rc);
+		goto out;
+	}
+
+	if (use_spnego) {
+		/* BB eventually need to add this */
+		cifs_dbg(VFS, "spnego not supported for SMB2 yet\n");
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+	sess_data->iov[1].iov_base = ntlmssp_blob;
+	sess_data->iov[1].iov_len = blob_length;
+
+	rc = SMB2_sess_sendreceive(sess_data);
+	if (rc)
+		goto out;
+
+	rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base;
+
+	spin_lock(&ses->ses_lock);
+	is_binding = (ses->ses_status == SES_GOOD);
+	spin_unlock(&ses->ses_lock);
+
+	/* keep existing ses id and flags if binding */
+	if (!is_binding) {
+		ses->Suid = le64_to_cpu(rsp->hdr.SessionId);
+		ses->session_flags = le16_to_cpu(rsp->SessionFlags);
+	}
+
+	rc = SMB2_sess_establish_session(sess_data);
+#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
+	if (ses->server->dialect < SMB30_PROT_ID) {
+		cifs_dbg(VFS, "%s: dumping generated SMB2 session keys\n", __func__);
+		/*
+		 * The session id is opaque in terms of endianness, so we can't
+		 * print it as a long long. we dump it as we got it on the wire
+		 */
+		cifs_dbg(VFS, "Session Id    %*ph\n", (int)sizeof(ses->Suid),
+			 &ses->Suid);
+		cifs_dbg(VFS, "Session Key   %*ph\n",
+			 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
+		cifs_dbg(VFS, "Signing Key   %*ph\n",
+			 SMB3_SIGN_KEY_SIZE, ses->auth_key.response);
+	}
+#endif
+out:
+	kfree_sensitive(ntlmssp_blob);
+	SMB2_sess_free_buffer(sess_data);
+	kfree_sensitive(ses->ntlmssp);
+	ses->ntlmssp = NULL;
+	sess_data->result = rc;
+	sess_data->func = NULL;
+}
+
+static int
+SMB2_select_sec(struct SMB2_sess_data *sess_data)
+{
+	int type;
+	struct cifs_ses *ses = sess_data->ses;
+	struct TCP_Server_Info *server = sess_data->server;
+
+	type = smb2_select_sectype(server, ses->sectype);
+	cifs_dbg(FYI, "sess setup type %d\n", type);
+	if (type == Unspecified) {
+		cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
+		return -EINVAL;
+	}
+
+	switch (type) {
+	case Kerberos:
+		sess_data->func = SMB2_auth_kerberos;
+		break;
+	case RawNTLMSSP:
+		sess_data->func = SMB2_sess_auth_rawntlmssp_negotiate;
+		break;
+	default:
+		cifs_dbg(VFS, "secType %d not supported!\n", type);
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+int
+SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
+		struct TCP_Server_Info *server,
+		const struct nls_table *nls_cp)
+{
+	int rc = 0;
+	struct SMB2_sess_data *sess_data;
+
+	cifs_dbg(FYI, "Session Setup\n");
+
+	if (!server) {
+		WARN(1, "%s: server is NULL!\n", __func__);
+		return -EIO;
+	}
+
+	sess_data = kzalloc(sizeof(struct SMB2_sess_data), GFP_KERNEL);
+	if (!sess_data)
+		return -ENOMEM;
+
+	sess_data->xid = xid;
+	sess_data->ses = ses;
+	sess_data->server = server;
+	sess_data->buf0_type = CIFS_NO_BUFFER;
+	sess_data->nls_cp = (struct nls_table *) nls_cp;
+	sess_data->previous_session = ses->Suid;
+
+	rc = SMB2_select_sec(sess_data);
+	if (rc)
+		goto out;
+
+	/*
+	 * Initialize the session hash with the server one.
+	 */
+	memcpy(ses->preauth_sha_hash, server->preauth_sha_hash,
+	       SMB2_PREAUTH_HASH_SIZE);
+
+	while (sess_data->func)
+		sess_data->func(sess_data);
+
+	if ((ses->session_flags & SMB2_SESSION_FLAG_IS_GUEST) && (ses->sign))
+		cifs_server_dbg(VFS, "signing requested but authenticated as guest\n");
+	rc = sess_data->result;
+out:
+	kfree_sensitive(sess_data);
+	return rc;
+}
+
+int
+SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
+{
+	struct smb_rqst rqst;
+	struct smb2_logoff_req *req; /* response is also trivial struct */
+	int rc = 0;
+	struct TCP_Server_Info *server;
+	int flags = 0;
+	unsigned int total_len;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int resp_buf_type;
+
+	cifs_dbg(FYI, "disconnect session %p\n", ses);
+
+	if (ses && (ses->server))
+		server = ses->server;
+	else
+		return -EIO;
+
+	/* no need to send SMB logoff if uid already closed due to reconnect */
+	spin_lock(&ses->chan_lock);
+	if (CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
+		spin_unlock(&ses->chan_lock);
+		goto smb2_session_already_dead;
+	}
+	spin_unlock(&ses->chan_lock);
+
+	rc = smb2_plain_req_init(SMB2_LOGOFF, NULL, ses->server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	 /* since no tcon, smb2_init can not do this, so do here */
+	req->hdr.SessionId = cpu_to_le64(ses->Suid);
+
+	if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA)
+		flags |= CIFS_TRANSFORM_REQ;
+	else if (server->sign)
+		req->hdr.Flags |= SMB2_FLAGS_SIGNED;
+
+	flags |= CIFS_NO_RSP_BUF;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, ses->server,
+			    &rqst, &resp_buf_type, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+	/*
+	 * No tcon so can't do
+	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
+	 */
+
+smb2_session_already_dead:
+	return rc;
+}
+
+static inline void cifs_stats_fail_inc(struct cifs_tcon *tcon, uint16_t code)
+{
+	cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_failed[code]);
+}
+
+#define MAX_SHARENAME_LENGTH (255 /* server */ + 80 /* share */ + 1 /* NULL */)
+
+/* These are similar values to what Windows uses */
+static inline void init_copy_chunk_defaults(struct cifs_tcon *tcon)
+{
+	tcon->max_chunks = 256;
+	tcon->max_bytes_chunk = 1048576;
+	tcon->max_bytes_copy = 16777216;
+}
+
+int
+SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
+	  struct cifs_tcon *tcon, const struct nls_table *cp)
+{
+	struct smb_rqst rqst;
+	struct smb2_tree_connect_req *req;
+	struct smb2_tree_connect_rsp *rsp = NULL;
+	struct kvec iov[2];
+	struct kvec rsp_iov = { NULL, 0 };
+	int rc = 0;
+	int resp_buftype;
+	int unc_path_len;
+	__le16 *unc_path = NULL;
+	int flags = 0;
+	unsigned int total_len;
+	struct TCP_Server_Info *server;
+
+	/* always use master channel */
+	server = ses->server;
+
+	cifs_dbg(FYI, "TCON\n");
+
+	if (!server || !tree)
+		return -EIO;
+
+	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
+	if (unc_path == NULL)
+		return -ENOMEM;
+
+	unc_path_len = cifs_strtoUTF16(unc_path, tree, strlen(tree), cp) + 1;
+	unc_path_len *= 2;
+	if (unc_path_len < 2) {
+		kfree(unc_path);
+		return -EINVAL;
+	}
+
+	/* SMB2 TREE_CONNECT request must be called with TreeId == 0 */
+	tcon->tid = 0;
+	atomic_set(&tcon->num_remote_opens, 0);
+	rc = smb2_plain_req_init(SMB2_TREE_CONNECT, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc) {
+		kfree(unc_path);
+		return rc;
+	}
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	iov[0].iov_base = (char *)req;
+	/* 1 for pad */
+	iov[0].iov_len = total_len - 1;
+
+	/* Testing shows that buffer offset must be at location of Buffer[0] */
+	req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req));
+	req->PathLength = cpu_to_le16(unc_path_len - 2);
+	iov[1].iov_base = unc_path;
+	iov[1].iov_len = unc_path_len;
+
+	/*
+	 * 3.11 tcon req must be signed if not encrypted. See MS-SMB2 3.2.4.1.1
+	 * unless it is guest or anonymous user. See MS-SMB2 3.2.5.3.1
+	 * (Samba servers don't always set the flag so also check if null user)
+	 */
+	if ((server->dialect == SMB311_PROT_ID) &&
+	    !smb3_encryption_required(tcon) &&
+	    !(ses->session_flags &
+		    (SMB2_SESSION_FLAG_IS_GUEST|SMB2_SESSION_FLAG_IS_NULL)) &&
+	    ((ses->user_name != NULL) || (ses->sectype == Kerberos)))
+		req->hdr.Flags |= SMB2_FLAGS_SIGNED;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 2;
+
+	/* Need 64 for max size write so ask for more in case not there yet */
+	if (server->credits >= server->max_credits)
+		req->hdr.CreditRequest = cpu_to_le16(0);
+	else
+		req->hdr.CreditRequest = cpu_to_le16(
+			min_t(int, server->max_credits -
+			      server->credits, 64));
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+	rsp = (struct smb2_tree_connect_rsp *)rsp_iov.iov_base;
+	trace_smb3_tcon(xid, tcon->tid, ses->Suid, tree, rc);
+	if ((rc != 0) || (rsp == NULL)) {
+		cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
+		tcon->need_reconnect = true;
+		goto tcon_error_exit;
+	}
+
+	switch (rsp->ShareType) {
+	case SMB2_SHARE_TYPE_DISK:
+		cifs_dbg(FYI, "connection to disk share\n");
+		break;
+	case SMB2_SHARE_TYPE_PIPE:
+		tcon->pipe = true;
+		cifs_dbg(FYI, "connection to pipe share\n");
+		break;
+	case SMB2_SHARE_TYPE_PRINT:
+		tcon->print = true;
+		cifs_dbg(FYI, "connection to printer\n");
+		break;
+	default:
+		cifs_server_dbg(VFS, "unknown share type %d\n", rsp->ShareType);
+		rc = -EOPNOTSUPP;
+		goto tcon_error_exit;
+	}
+
+	tcon->share_flags = le32_to_cpu(rsp->ShareFlags);
+	tcon->capabilities = rsp->Capabilities; /* we keep caps little endian */
+	tcon->maximal_access = le32_to_cpu(rsp->MaximalAccess);
+	tcon->tid = le32_to_cpu(rsp->hdr.Id.SyncId.TreeId);
+	strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
+
+	if ((rsp->Capabilities & SMB2_SHARE_CAP_DFS) &&
+	    ((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
+		cifs_tcon_dbg(VFS, "DFS capability contradicts DFS flag\n");
+
+	if (tcon->seal &&
+	    !(server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
+		cifs_tcon_dbg(VFS, "Encryption is requested but not supported\n");
+
+	init_copy_chunk_defaults(tcon);
+	if (server->ops->validate_negotiate)
+		rc = server->ops->validate_negotiate(xid, tcon);
+tcon_exit:
+
+	free_rsp_buf(resp_buftype, rsp);
+	kfree(unc_path);
+	return rc;
+
+tcon_error_exit:
+	if (rsp && rsp->hdr.Status == STATUS_BAD_NETWORK_NAME)
+		cifs_tcon_dbg(VFS, "BAD_NETWORK_NAME: %s\n", tree);
+	goto tcon_exit;
+}
+
+int
+SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon)
+{
+	struct smb_rqst rqst;
+	struct smb2_tree_disconnect_req *req; /* response is trivial */
+	int rc = 0;
+	struct cifs_ses *ses = tcon->ses;
+	int flags = 0;
+	unsigned int total_len;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int resp_buf_type;
+
+	cifs_dbg(FYI, "Tree Disconnect\n");
+
+	if (!ses || !(ses->server))
+		return -EIO;
+
+	trace_smb3_tdis_enter(xid, tcon->tid, ses->Suid, tcon->tree_name);
+	spin_lock(&ses->chan_lock);
+	if ((tcon->need_reconnect) ||
+	    (CIFS_ALL_CHANS_NEED_RECONNECT(tcon->ses))) {
+		spin_unlock(&ses->chan_lock);
+		return 0;
+	}
+	spin_unlock(&ses->chan_lock);
+
+	invalidate_all_cached_dirs(tcon);
+
+	rc = smb2_plain_req_init(SMB2_TREE_DISCONNECT, tcon, ses->server,
+				 (void **) &req,
+				 &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	flags |= CIFS_NO_RSP_BUF;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, ses->server,
+			    &rqst, &resp_buf_type, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_TREE_DISCONNECT_HE);
+		trace_smb3_tdis_err(xid, tcon->tid, ses->Suid, rc);
+	}
+	trace_smb3_tdis_done(xid, tcon->tid, ses->Suid);
+
+	return rc;
+}
+
+
+static struct create_durable *
+create_durable_buf(void)
+{
+	struct create_durable *buf;
+
+	buf = kzalloc(sizeof(struct create_durable), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset = cpu_to_le16(offsetof
+					(struct create_durable, Data));
+	buf->ccontext.DataLength = cpu_to_le32(16);
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof
+				(struct create_durable, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+	/* SMB2_CREATE_DURABLE_HANDLE_REQUEST is "DHnQ" */
+	buf->Name[0] = 'D';
+	buf->Name[1] = 'H';
+	buf->Name[2] = 'n';
+	buf->Name[3] = 'Q';
+	return buf;
+}
+
+static struct create_durable *
+create_reconnect_durable_buf(struct cifs_fid *fid)
+{
+	struct create_durable *buf;
+
+	buf = kzalloc(sizeof(struct create_durable), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset = cpu_to_le16(offsetof
+					(struct create_durable, Data));
+	buf->ccontext.DataLength = cpu_to_le32(16);
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof
+				(struct create_durable, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+	buf->Data.Fid.PersistentFileId = fid->persistent_fid;
+	buf->Data.Fid.VolatileFileId = fid->volatile_fid;
+	/* SMB2_CREATE_DURABLE_HANDLE_RECONNECT is "DHnC" */
+	buf->Name[0] = 'D';
+	buf->Name[1] = 'H';
+	buf->Name[2] = 'n';
+	buf->Name[3] = 'C';
+	return buf;
+}
+
+static void
+parse_query_id_ctxt(struct create_context *cc, struct smb2_file_all_info *buf)
+{
+	struct create_on_disk_id *pdisk_id = (struct create_on_disk_id *)cc;
+
+	cifs_dbg(FYI, "parse query id context 0x%llx 0x%llx\n",
+		pdisk_id->DiskFileId, pdisk_id->VolumeId);
+	buf->IndexNumber = pdisk_id->DiskFileId;
+}
+
+static void
+parse_posix_ctxt(struct create_context *cc, struct smb2_file_all_info *info,
+		 struct create_posix_rsp *posix)
+{
+	int sid_len;
+	u8 *beg = (u8 *)cc + le16_to_cpu(cc->DataOffset);
+	u8 *end = beg + le32_to_cpu(cc->DataLength);
+	u8 *sid;
+
+	memset(posix, 0, sizeof(*posix));
+
+	posix->nlink = le32_to_cpu(*(__le32 *)(beg + 0));
+	posix->reparse_tag = le32_to_cpu(*(__le32 *)(beg + 4));
+	posix->mode = le32_to_cpu(*(__le32 *)(beg + 8));
+
+	sid = beg + 12;
+	sid_len = posix_info_sid_size(sid, end);
+	if (sid_len < 0) {
+		cifs_dbg(VFS, "bad owner sid in posix create response\n");
+		return;
+	}
+	memcpy(&posix->owner, sid, sid_len);
+
+	sid = sid + sid_len;
+	sid_len = posix_info_sid_size(sid, end);
+	if (sid_len < 0) {
+		cifs_dbg(VFS, "bad group sid in posix create response\n");
+		return;
+	}
+	memcpy(&posix->group, sid, sid_len);
+
+	cifs_dbg(FYI, "nlink=%d mode=%o reparse_tag=%x\n",
+		 posix->nlink, posix->mode, posix->reparse_tag);
+}
+
+void
+smb2_parse_contexts(struct TCP_Server_Info *server,
+		    struct smb2_create_rsp *rsp,
+		    unsigned int *epoch, char *lease_key, __u8 *oplock,
+		    struct smb2_file_all_info *buf,
+		    struct create_posix_rsp *posix)
+{
+	char *data_offset;
+	struct create_context *cc;
+	unsigned int next;
+	unsigned int remaining;
+	char *name;
+	static const char smb3_create_tag_posix[] = {
+		0x93, 0xAD, 0x25, 0x50, 0x9C,
+		0xB4, 0x11, 0xE7, 0xB4, 0x23, 0x83,
+		0xDE, 0x96, 0x8B, 0xCD, 0x7C
+	};
+
+	*oplock = 0;
+	data_offset = (char *)rsp + le32_to_cpu(rsp->CreateContextsOffset);
+	remaining = le32_to_cpu(rsp->CreateContextsLength);
+	cc = (struct create_context *)data_offset;
+
+	/* Initialize inode number to 0 in case no valid data in qfid context */
+	if (buf)
+		buf->IndexNumber = 0;
+
+	while (remaining >= sizeof(struct create_context)) {
+		name = le16_to_cpu(cc->NameOffset) + (char *)cc;
+		if (le16_to_cpu(cc->NameLength) == 4 &&
+		    strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4) == 0)
+			*oplock = server->ops->parse_lease_buf(cc, epoch,
+							   lease_key);
+		else if (buf && (le16_to_cpu(cc->NameLength) == 4) &&
+		    strncmp(name, SMB2_CREATE_QUERY_ON_DISK_ID, 4) == 0)
+			parse_query_id_ctxt(cc, buf);
+		else if ((le16_to_cpu(cc->NameLength) == 16)) {
+			if (posix &&
+			    memcmp(name, smb3_create_tag_posix, 16) == 0)
+				parse_posix_ctxt(cc, buf, posix);
+		}
+		/* else {
+			cifs_dbg(FYI, "Context not matched with len %d\n",
+				le16_to_cpu(cc->NameLength));
+			cifs_dump_mem("Cctxt name: ", name, 4);
+		} */
+
+		next = le32_to_cpu(cc->Next);
+		if (!next)
+			break;
+		remaining -= next;
+		cc = (struct create_context *)((char *)cc + next);
+	}
+
+	if (rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
+		*oplock = rsp->OplockLevel;
+
+	return;
+}
+
+static int
+add_lease_context(struct TCP_Server_Info *server, struct kvec *iov,
+		  unsigned int *num_iovec, u8 *lease_key, __u8 *oplock)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	iov[num].iov_base = server->ops->create_lease_buf(lease_key, *oplock);
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = server->vals->create_lease_size;
+	req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_LEASE;
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset = cpu_to_le32(
+				sizeof(struct smb2_create_req) +
+				iov[num - 1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength,
+		     server->vals->create_lease_size);
+	*num_iovec = num + 1;
+	return 0;
+}
+
+static struct create_durable_v2 *
+create_durable_v2_buf(struct cifs_open_parms *oparms)
+{
+	struct cifs_fid *pfid = oparms->fid;
+	struct create_durable_v2 *buf;
+
+	buf = kzalloc(sizeof(struct create_durable_v2), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset = cpu_to_le16(offsetof
+					(struct create_durable_v2, dcontext));
+	buf->ccontext.DataLength = cpu_to_le32(sizeof(struct durable_context_v2));
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof
+				(struct create_durable_v2, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+
+	/*
+	 * NB: Handle timeout defaults to 0, which allows server to choose
+	 * (most servers default to 120 seconds) and most clients default to 0.
+	 * This can be overridden at mount ("handletimeout=") if the user wants
+	 * a different persistent (or resilient) handle timeout for all opens
+	 * opens on a particular SMB3 mount.
+	 */
+	buf->dcontext.Timeout = cpu_to_le32(oparms->tcon->handle_timeout);
+	buf->dcontext.Flags = cpu_to_le32(SMB2_DHANDLE_FLAG_PERSISTENT);
+	generate_random_uuid(buf->dcontext.CreateGuid);
+	memcpy(pfid->create_guid, buf->dcontext.CreateGuid, 16);
+
+	/* SMB2_CREATE_DURABLE_HANDLE_REQUEST is "DH2Q" */
+	buf->Name[0] = 'D';
+	buf->Name[1] = 'H';
+	buf->Name[2] = '2';
+	buf->Name[3] = 'Q';
+	return buf;
+}
+
+static struct create_durable_handle_reconnect_v2 *
+create_reconnect_durable_v2_buf(struct cifs_fid *fid)
+{
+	struct create_durable_handle_reconnect_v2 *buf;
+
+	buf = kzalloc(sizeof(struct create_durable_handle_reconnect_v2),
+			GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset =
+		cpu_to_le16(offsetof(struct create_durable_handle_reconnect_v2,
+				     dcontext));
+	buf->ccontext.DataLength =
+		cpu_to_le32(sizeof(struct durable_reconnect_context_v2));
+	buf->ccontext.NameOffset =
+		cpu_to_le16(offsetof(struct create_durable_handle_reconnect_v2,
+			    Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+
+	buf->dcontext.Fid.PersistentFileId = fid->persistent_fid;
+	buf->dcontext.Fid.VolatileFileId = fid->volatile_fid;
+	buf->dcontext.Flags = cpu_to_le32(SMB2_DHANDLE_FLAG_PERSISTENT);
+	memcpy(buf->dcontext.CreateGuid, fid->create_guid, 16);
+
+	/* SMB2_CREATE_DURABLE_HANDLE_RECONNECT_V2 is "DH2C" */
+	buf->Name[0] = 'D';
+	buf->Name[1] = 'H';
+	buf->Name[2] = '2';
+	buf->Name[3] = 'C';
+	return buf;
+}
+
+static int
+add_durable_v2_context(struct kvec *iov, unsigned int *num_iovec,
+		    struct cifs_open_parms *oparms)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	iov[num].iov_base = create_durable_v2_buf(oparms);
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct create_durable_v2);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset =
+			cpu_to_le32(sizeof(struct smb2_create_req) +
+								iov[1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_durable_v2));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+static int
+add_durable_reconnect_v2_context(struct kvec *iov, unsigned int *num_iovec,
+		    struct cifs_open_parms *oparms)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	/* indicate that we don't need to relock the file */
+	oparms->reconnect = false;
+
+	iov[num].iov_base = create_reconnect_durable_v2_buf(oparms->fid);
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct create_durable_handle_reconnect_v2);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset =
+			cpu_to_le32(sizeof(struct smb2_create_req) +
+								iov[1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength,
+			sizeof(struct create_durable_handle_reconnect_v2));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+static int
+add_durable_context(struct kvec *iov, unsigned int *num_iovec,
+		    struct cifs_open_parms *oparms, bool use_persistent)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	if (use_persistent) {
+		if (oparms->reconnect)
+			return add_durable_reconnect_v2_context(iov, num_iovec,
+								oparms);
+		else
+			return add_durable_v2_context(iov, num_iovec, oparms);
+	}
+
+	if (oparms->reconnect) {
+		iov[num].iov_base = create_reconnect_durable_buf(oparms->fid);
+		/* indicate that we don't need to relock the file */
+		oparms->reconnect = false;
+	} else
+		iov[num].iov_base = create_durable_buf();
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct create_durable);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset =
+			cpu_to_le32(sizeof(struct smb2_create_req) +
+								iov[1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_durable));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+/* See MS-SMB2 2.2.13.2.7 */
+static struct crt_twarp_ctxt *
+create_twarp_buf(__u64 timewarp)
+{
+	struct crt_twarp_ctxt *buf;
+
+	buf = kzalloc(sizeof(struct crt_twarp_ctxt), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset = cpu_to_le16(offsetof
+					(struct crt_twarp_ctxt, Timestamp));
+	buf->ccontext.DataLength = cpu_to_le32(8);
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof
+				(struct crt_twarp_ctxt, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+	/* SMB2_CREATE_TIMEWARP_TOKEN is "TWrp" */
+	buf->Name[0] = 'T';
+	buf->Name[1] = 'W';
+	buf->Name[2] = 'r';
+	buf->Name[3] = 'p';
+	buf->Timestamp = cpu_to_le64(timewarp);
+	return buf;
+}
+
+/* See MS-SMB2 2.2.13.2.7 */
+static int
+add_twarp_context(struct kvec *iov, unsigned int *num_iovec, __u64 timewarp)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	iov[num].iov_base = create_twarp_buf(timewarp);
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct crt_twarp_ctxt);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset = cpu_to_le32(
+				sizeof(struct smb2_create_req) +
+				iov[num - 1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, sizeof(struct crt_twarp_ctxt));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+/* See See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx */
+static void setup_owner_group_sids(char *buf)
+{
+	struct owner_group_sids *sids = (struct owner_group_sids *)buf;
+
+	/* Populate the user ownership fields S-1-5-88-1 */
+	sids->owner.Revision = 1;
+	sids->owner.NumAuth = 3;
+	sids->owner.Authority[5] = 5;
+	sids->owner.SubAuthorities[0] = cpu_to_le32(88);
+	sids->owner.SubAuthorities[1] = cpu_to_le32(1);
+	sids->owner.SubAuthorities[2] = cpu_to_le32(current_fsuid().val);
+
+	/* Populate the group ownership fields S-1-5-88-2 */
+	sids->group.Revision = 1;
+	sids->group.NumAuth = 3;
+	sids->group.Authority[5] = 5;
+	sids->group.SubAuthorities[0] = cpu_to_le32(88);
+	sids->group.SubAuthorities[1] = cpu_to_le32(2);
+	sids->group.SubAuthorities[2] = cpu_to_le32(current_fsgid().val);
+
+	cifs_dbg(FYI, "owner S-1-5-88-1-%d, group S-1-5-88-2-%d\n", current_fsuid().val, current_fsgid().val);
+}
+
+/* See MS-SMB2 2.2.13.2.2 and MS-DTYP 2.4.6 */
+static struct crt_sd_ctxt *
+create_sd_buf(umode_t mode, bool set_owner, unsigned int *len)
+{
+	struct crt_sd_ctxt *buf;
+	__u8 *ptr, *aclptr;
+	unsigned int acelen, acl_size, ace_count;
+	unsigned int owner_offset = 0;
+	unsigned int group_offset = 0;
+	struct smb3_acl acl = {};
+
+	*len = round_up(sizeof(struct crt_sd_ctxt) + (sizeof(struct cifs_ace) * 4), 8);
+
+	if (set_owner) {
+		/* sizeof(struct owner_group_sids) is already multiple of 8 so no need to round */
+		*len += sizeof(struct owner_group_sids);
+	}
+
+	buf = kzalloc(*len, GFP_KERNEL);
+	if (buf == NULL)
+		return buf;
+
+	ptr = (__u8 *)&buf[1];
+	if (set_owner) {
+		/* offset fields are from beginning of security descriptor not of create context */
+		owner_offset = ptr - (__u8 *)&buf->sd;
+		buf->sd.OffsetOwner = cpu_to_le32(owner_offset);
+		group_offset = owner_offset + offsetof(struct owner_group_sids, group);
+		buf->sd.OffsetGroup = cpu_to_le32(group_offset);
+
+		setup_owner_group_sids(ptr);
+		ptr += sizeof(struct owner_group_sids);
+	} else {
+		buf->sd.OffsetOwner = 0;
+		buf->sd.OffsetGroup = 0;
+	}
+
+	buf->ccontext.DataOffset = cpu_to_le16(offsetof(struct crt_sd_ctxt, sd));
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof(struct crt_sd_ctxt, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+	/* SMB2_CREATE_SD_BUFFER_TOKEN is "SecD" */
+	buf->Name[0] = 'S';
+	buf->Name[1] = 'e';
+	buf->Name[2] = 'c';
+	buf->Name[3] = 'D';
+	buf->sd.Revision = 1;  /* Must be one see MS-DTYP 2.4.6 */
+
+	/*
+	 * ACL is "self relative" ie ACL is stored in contiguous block of memory
+	 * and "DP" ie the DACL is present
+	 */
+	buf->sd.Control = cpu_to_le16(ACL_CONTROL_SR | ACL_CONTROL_DP);
+
+	/* offset owner, group and Sbz1 and SACL are all zero */
+	buf->sd.OffsetDacl = cpu_to_le32(ptr - (__u8 *)&buf->sd);
+	/* Ship the ACL for now. we will copy it into buf later. */
+	aclptr = ptr;
+	ptr += sizeof(struct smb3_acl);
+
+	/* create one ACE to hold the mode embedded in reserved special SID */
+	acelen = setup_special_mode_ACE((struct cifs_ace *)ptr, (__u64)mode);
+	ptr += acelen;
+	acl_size = acelen + sizeof(struct smb3_acl);
+	ace_count = 1;
+
+	if (set_owner) {
+		/* we do not need to reallocate buffer to add the two more ACEs. plenty of space */
+		acelen = setup_special_user_owner_ACE((struct cifs_ace *)ptr);
+		ptr += acelen;
+		acl_size += acelen;
+		ace_count += 1;
+	}
+
+	/* and one more ACE to allow access for authenticated users */
+	acelen = setup_authusers_ACE((struct cifs_ace *)ptr);
+	ptr += acelen;
+	acl_size += acelen;
+	ace_count += 1;
+
+	acl.AclRevision = ACL_REVISION; /* See 2.4.4.1 of MS-DTYP */
+	acl.AclSize = cpu_to_le16(acl_size);
+	acl.AceCount = cpu_to_le16(ace_count);
+	/* acl.Sbz1 and Sbz2 MBZ so are not set here, but initialized above */
+	memcpy(aclptr, &acl, sizeof(struct smb3_acl));
+
+	buf->ccontext.DataLength = cpu_to_le32(ptr - (__u8 *)&buf->sd);
+	*len = round_up((unsigned int)(ptr - (__u8 *)buf), 8);
+
+	return buf;
+}
+
+static int
+add_sd_context(struct kvec *iov, unsigned int *num_iovec, umode_t mode, bool set_owner)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+	unsigned int len = 0;
+
+	iov[num].iov_base = create_sd_buf(mode, set_owner, &len);
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = len;
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset = cpu_to_le32(
+				sizeof(struct smb2_create_req) +
+				iov[num - 1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, len);
+	*num_iovec = num + 1;
+	return 0;
+}
+
+static struct crt_query_id_ctxt *
+create_query_id_buf(void)
+{
+	struct crt_query_id_ctxt *buf;
+
+	buf = kzalloc(sizeof(struct crt_query_id_ctxt), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	buf->ccontext.DataOffset = cpu_to_le16(0);
+	buf->ccontext.DataLength = cpu_to_le32(0);
+	buf->ccontext.NameOffset = cpu_to_le16(offsetof
+				(struct crt_query_id_ctxt, Name));
+	buf->ccontext.NameLength = cpu_to_le16(4);
+	/* SMB2_CREATE_QUERY_ON_DISK_ID is "QFid" */
+	buf->Name[0] = 'Q';
+	buf->Name[1] = 'F';
+	buf->Name[2] = 'i';
+	buf->Name[3] = 'd';
+	return buf;
+}
+
+/* See MS-SMB2 2.2.13.2.9 */
+static int
+add_query_id_context(struct kvec *iov, unsigned int *num_iovec)
+{
+	struct smb2_create_req *req = iov[0].iov_base;
+	unsigned int num = *num_iovec;
+
+	iov[num].iov_base = create_query_id_buf();
+	if (iov[num].iov_base == NULL)
+		return -ENOMEM;
+	iov[num].iov_len = sizeof(struct crt_query_id_ctxt);
+	if (!req->CreateContextsOffset)
+		req->CreateContextsOffset = cpu_to_le32(
+				sizeof(struct smb2_create_req) +
+				iov[num - 1].iov_len);
+	le32_add_cpu(&req->CreateContextsLength, sizeof(struct crt_query_id_ctxt));
+	*num_iovec = num + 1;
+	return 0;
+}
+
+static int
+alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
+			    const char *treename, const __le16 *path)
+{
+	int treename_len, path_len;
+	struct nls_table *cp;
+	const __le16 sep[] = {cpu_to_le16('\\'), cpu_to_le16(0x0000)};
+
+	/*
+	 * skip leading "\\"
+	 */
+	treename_len = strlen(treename);
+	if (treename_len < 2 || !(treename[0] == '\\' && treename[1] == '\\'))
+		return -EINVAL;
+
+	treename += 2;
+	treename_len -= 2;
+
+	path_len = UniStrnlen((wchar_t *)path, PATH_MAX);
+
+	/* make room for one path separator only if @path isn't empty */
+	*out_len = treename_len + (path[0] ? 1 : 0) + path_len;
+
+	/*
+	 * final path needs to be 8-byte aligned as specified in
+	 * MS-SMB2 2.2.13 SMB2 CREATE Request.
+	 */
+	*out_size = round_up(*out_len * sizeof(__le16), 8);
+	*out_path = kzalloc(*out_size + sizeof(__le16) /* null */, GFP_KERNEL);
+	if (!*out_path)
+		return -ENOMEM;
+
+	cp = load_nls_default();
+	cifs_strtoUTF16(*out_path, treename, treename_len, cp);
+
+	/* Do not append the separator if the path is empty */
+	if (path[0] != cpu_to_le16(0x0000)) {
+		UniStrcat(*out_path, sep);
+		UniStrcat(*out_path, path);
+	}
+
+	unload_nls(cp);
+
+	return 0;
+}
+
+int smb311_posix_mkdir(const unsigned int xid, struct inode *inode,
+			       umode_t mode, struct cifs_tcon *tcon,
+			       const char *full_path,
+			       struct cifs_sb_info *cifs_sb)
+{
+	struct smb_rqst rqst;
+	struct smb2_create_req *req;
+	struct smb2_create_rsp *rsp = NULL;
+	struct cifs_ses *ses = tcon->ses;
+	struct kvec iov[3]; /* make sure at least one for each open context */
+	struct kvec rsp_iov = {NULL, 0};
+	int resp_buftype;
+	int uni_path_len;
+	__le16 *copy_path = NULL;
+	int copy_size;
+	int rc = 0;
+	unsigned int n_iov = 2;
+	__u32 file_attributes = 0;
+	char *pc_buf = NULL;
+	int flags = 0;
+	unsigned int total_len;
+	__le16 *utf16_path = NULL;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+
+	cifs_dbg(FYI, "mkdir\n");
+
+	/* resource #1: path allocation */
+	utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
+	if (!utf16_path)
+		return -ENOMEM;
+
+	if (!ses || !server) {
+		rc = -EIO;
+		goto err_free_path;
+	}
+
+	/* resource #2: request */
+	rc = smb2_plain_req_init(SMB2_CREATE, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		goto err_free_path;
+
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	req->ImpersonationLevel = IL_IMPERSONATION;
+	req->DesiredAccess = cpu_to_le32(FILE_WRITE_ATTRIBUTES);
+	/* File attributes ignored on open (used in create though) */
+	req->FileAttributes = cpu_to_le32(file_attributes);
+	req->ShareAccess = FILE_SHARE_ALL_LE;
+	req->CreateDisposition = cpu_to_le32(FILE_CREATE);
+	req->CreateOptions = cpu_to_le32(CREATE_NOT_FILE);
+
+	iov[0].iov_base = (char *)req;
+	/* -1 since last byte is buf[0] which is sent below (path) */
+	iov[0].iov_len = total_len - 1;
+
+	req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req));
+
+	/* [MS-SMB2] 2.2.13 NameOffset:
+	 * If SMB2_FLAGS_DFS_OPERATIONS is set in the Flags field of
+	 * the SMB2 header, the file name includes a prefix that will
+	 * be processed during DFS name normalization as specified in
+	 * section 3.3.5.9. Otherwise, the file name is relative to
+	 * the share that is identified by the TreeId in the SMB2
+	 * header.
+	 */
+	if (tcon->share_flags & SHI1005_FLAGS_DFS) {
+		int name_len;
+
+		req->hdr.Flags |= SMB2_FLAGS_DFS_OPERATIONS;
+		rc = alloc_path_with_tree_prefix(&copy_path, &copy_size,
+						 &name_len,
+						 tcon->tree_name, utf16_path);
+		if (rc)
+			goto err_free_req;
+
+		req->NameLength = cpu_to_le16(name_len * 2);
+		uni_path_len = copy_size;
+		/* free before overwriting resource */
+		kfree(utf16_path);
+		utf16_path = copy_path;
+	} else {
+		uni_path_len = (2 * UniStrnlen((wchar_t *)utf16_path, PATH_MAX)) + 2;
+		/* MUST set path len (NameLength) to 0 opening root of share */
+		req->NameLength = cpu_to_le16(uni_path_len - 2);
+		if (uni_path_len % 8 != 0) {
+			copy_size = roundup(uni_path_len, 8);
+			copy_path = kzalloc(copy_size, GFP_KERNEL);
+			if (!copy_path) {
+				rc = -ENOMEM;
+				goto err_free_req;
+			}
+			memcpy((char *)copy_path, (const char *)utf16_path,
+			       uni_path_len);
+			uni_path_len = copy_size;
+			/* free before overwriting resource */
+			kfree(utf16_path);
+			utf16_path = copy_path;
+		}
+	}
+
+	iov[1].iov_len = uni_path_len;
+	iov[1].iov_base = utf16_path;
+	req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_NONE;
+
+	if (tcon->posix_extensions) {
+		/* resource #3: posix buf */
+		rc = add_posix_context(iov, &n_iov, mode);
+		if (rc)
+			goto err_free_req;
+		pc_buf = iov[n_iov-1].iov_base;
+	}
+
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = n_iov;
+
+	/* no need to inc num_remote_opens because we close it just below */
+	trace_smb3_posix_mkdir_enter(xid, tcon->tid, ses->Suid, full_path, CREATE_NOT_FILE,
+				    FILE_WRITE_ATTRIBUTES);
+	/* resource #4: response buffer */
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
+		trace_smb3_posix_mkdir_err(xid, tcon->tid, ses->Suid,
+					   CREATE_NOT_FILE,
+					   FILE_WRITE_ATTRIBUTES, rc);
+		goto err_free_rsp_buf;
+	}
+
+	/*
+	 * Although unlikely to be possible for rsp to be null and rc not set,
+	 * adding check below is slightly safer long term (and quiets Coverity
+	 * warning)
+	 */
+	rsp = (struct smb2_create_rsp *)rsp_iov.iov_base;
+	if (rsp == NULL) {
+		rc = -EIO;
+		kfree(pc_buf);
+		goto err_free_req;
+	}
+
+	trace_smb3_posix_mkdir_done(xid, rsp->PersistentFileId, tcon->tid, ses->Suid,
+				    CREATE_NOT_FILE, FILE_WRITE_ATTRIBUTES);
+
+	SMB2_close(xid, tcon, rsp->PersistentFileId, rsp->VolatileFileId);
+
+	/* Eventually save off posix specific response info and timestaps */
+
+err_free_rsp_buf:
+	free_rsp_buf(resp_buftype, rsp);
+	kfree(pc_buf);
+err_free_req:
+	cifs_small_buf_release(req);
+err_free_path:
+	kfree(utf16_path);
+	return rc;
+}
+
+int
+SMB2_open_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+	       struct smb_rqst *rqst, __u8 *oplock,
+	       struct cifs_open_parms *oparms, __le16 *path)
+{
+	struct smb2_create_req *req;
+	unsigned int n_iov = 2;
+	__u32 file_attributes = 0;
+	int copy_size;
+	int uni_path_len;
+	unsigned int total_len;
+	struct kvec *iov = rqst->rq_iov;
+	__le16 *copy_path;
+	int rc;
+
+	rc = smb2_plain_req_init(SMB2_CREATE, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	iov[0].iov_base = (char *)req;
+	/* -1 since last byte is buf[0] which is sent below (path) */
+	iov[0].iov_len = total_len - 1;
+
+	if (oparms->create_options & CREATE_OPTION_READONLY)
+		file_attributes |= ATTR_READONLY;
+	if (oparms->create_options & CREATE_OPTION_SPECIAL)
+		file_attributes |= ATTR_SYSTEM;
+
+	req->ImpersonationLevel = IL_IMPERSONATION;
+	req->DesiredAccess = cpu_to_le32(oparms->desired_access);
+	/* File attributes ignored on open (used in create though) */
+	req->FileAttributes = cpu_to_le32(file_attributes);
+	req->ShareAccess = FILE_SHARE_ALL_LE;
+
+	req->CreateDisposition = cpu_to_le32(oparms->disposition);
+	req->CreateOptions = cpu_to_le32(oparms->create_options & CREATE_OPTIONS_MASK);
+	req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req));
+
+	/* [MS-SMB2] 2.2.13 NameOffset:
+	 * If SMB2_FLAGS_DFS_OPERATIONS is set in the Flags field of
+	 * the SMB2 header, the file name includes a prefix that will
+	 * be processed during DFS name normalization as specified in
+	 * section 3.3.5.9. Otherwise, the file name is relative to
+	 * the share that is identified by the TreeId in the SMB2
+	 * header.
+	 */
+	if (tcon->share_flags & SHI1005_FLAGS_DFS) {
+		int name_len;
+
+		req->hdr.Flags |= SMB2_FLAGS_DFS_OPERATIONS;
+		rc = alloc_path_with_tree_prefix(&copy_path, &copy_size,
+						 &name_len,
+						 tcon->tree_name, path);
+		if (rc)
+			return rc;
+		req->NameLength = cpu_to_le16(name_len * 2);
+		uni_path_len = copy_size;
+		path = copy_path;
+	} else {
+		uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
+		/* MUST set path len (NameLength) to 0 opening root of share */
+		req->NameLength = cpu_to_le16(uni_path_len - 2);
+		copy_size = round_up(uni_path_len, 8);
+		copy_path = kzalloc(copy_size, GFP_KERNEL);
+		if (!copy_path)
+			return -ENOMEM;
+		memcpy((char *)copy_path, (const char *)path,
+		       uni_path_len);
+		uni_path_len = copy_size;
+		path = copy_path;
+	}
+
+	iov[1].iov_len = uni_path_len;
+	iov[1].iov_base = path;
+
+	if ((!server->oplocks) || (tcon->no_lease))
+		*oplock = SMB2_OPLOCK_LEVEL_NONE;
+
+	if (!(server->capabilities & SMB2_GLOBAL_CAP_LEASING) ||
+	    *oplock == SMB2_OPLOCK_LEVEL_NONE)
+		req->RequestedOplockLevel = *oplock;
+	else if (!(server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING) &&
+		  (oparms->create_options & CREATE_NOT_FILE))
+		req->RequestedOplockLevel = *oplock; /* no srv lease support */
+	else {
+		rc = add_lease_context(server, iov, &n_iov,
+				       oparms->fid->lease_key, oplock);
+		if (rc)
+			return rc;
+	}
+
+	if (*oplock == SMB2_OPLOCK_LEVEL_BATCH) {
+		/* need to set Next field of lease context if we request it */
+		if (server->capabilities & SMB2_GLOBAL_CAP_LEASING) {
+			struct create_context *ccontext =
+			    (struct create_context *)iov[n_iov-1].iov_base;
+			ccontext->Next =
+				cpu_to_le32(server->vals->create_lease_size);
+		}
+
+		rc = add_durable_context(iov, &n_iov, oparms,
+					tcon->use_persistent);
+		if (rc)
+			return rc;
+	}
+
+	if (tcon->posix_extensions) {
+		if (n_iov > 2) {
+			struct create_context *ccontext =
+			    (struct create_context *)iov[n_iov-1].iov_base;
+			ccontext->Next =
+				cpu_to_le32(iov[n_iov-1].iov_len);
+		}
+
+		rc = add_posix_context(iov, &n_iov, oparms->mode);
+		if (rc)
+			return rc;
+	}
+
+	if (tcon->snapshot_time) {
+		cifs_dbg(FYI, "adding snapshot context\n");
+		if (n_iov > 2) {
+			struct create_context *ccontext =
+			    (struct create_context *)iov[n_iov-1].iov_base;
+			ccontext->Next =
+				cpu_to_le32(iov[n_iov-1].iov_len);
+		}
+
+		rc = add_twarp_context(iov, &n_iov, tcon->snapshot_time);
+		if (rc)
+			return rc;
+	}
+
+	if ((oparms->disposition != FILE_OPEN) && (oparms->cifs_sb)) {
+		bool set_mode;
+		bool set_owner;
+
+		if ((oparms->cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID) &&
+		    (oparms->mode != ACL_NO_MODE))
+			set_mode = true;
+		else {
+			set_mode = false;
+			oparms->mode = ACL_NO_MODE;
+		}
+
+		if (oparms->cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UID_FROM_ACL)
+			set_owner = true;
+		else
+			set_owner = false;
+
+		if (set_owner | set_mode) {
+			if (n_iov > 2) {
+				struct create_context *ccontext =
+				    (struct create_context *)iov[n_iov-1].iov_base;
+				ccontext->Next = cpu_to_le32(iov[n_iov-1].iov_len);
+			}
+
+			cifs_dbg(FYI, "add sd with mode 0x%x\n", oparms->mode);
+			rc = add_sd_context(iov, &n_iov, oparms->mode, set_owner);
+			if (rc)
+				return rc;
+		}
+	}
+
+	if (n_iov > 2) {
+		struct create_context *ccontext =
+			(struct create_context *)iov[n_iov-1].iov_base;
+		ccontext->Next = cpu_to_le32(iov[n_iov-1].iov_len);
+	}
+	add_query_id_context(iov, &n_iov);
+
+	rqst->rq_nvec = n_iov;
+	return 0;
+}
+
+/* rq_iov[0] is the request and is released by cifs_small_buf_release().
+ * All other vectors are freed by kfree().
+ */
+void
+SMB2_open_free(struct smb_rqst *rqst)
+{
+	int i;
+
+	if (rqst && rqst->rq_iov) {
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base);
+		for (i = 1; i < rqst->rq_nvec; i++)
+			if (rqst->rq_iov[i].iov_base != smb2_padding)
+				kfree(rqst->rq_iov[i].iov_base);
+	}
+}
+
+int
+SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
+	  __u8 *oplock, struct smb2_file_all_info *buf,
+	  struct create_posix_rsp *posix,
+	  struct kvec *err_iov, int *buftype)
+{
+	struct smb_rqst rqst;
+	struct smb2_create_rsp *rsp = NULL;
+	struct cifs_tcon *tcon = oparms->tcon;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	struct kvec iov[SMB2_CREATE_IOV_SIZE];
+	struct kvec rsp_iov = {NULL, 0};
+	int resp_buftype = CIFS_NO_BUFFER;
+	int rc = 0;
+	int flags = 0;
+
+	cifs_dbg(FYI, "create/open\n");
+	if (!ses || !server)
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = SMB2_CREATE_IOV_SIZE;
+
+	rc = SMB2_open_init(tcon, server,
+			    &rqst, oplock, oparms, path);
+	if (rc)
+		goto creat_exit;
+
+	trace_smb3_open_enter(xid, tcon->tid, tcon->ses->Suid, oparms->path,
+		oparms->create_options, oparms->desired_access);
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags,
+			    &rsp_iov);
+	rsp = (struct smb2_create_rsp *)rsp_iov.iov_base;
+
+	if (rc != 0) {
+		cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
+		if (err_iov && rsp) {
+			*err_iov = rsp_iov;
+			*buftype = resp_buftype;
+			resp_buftype = CIFS_NO_BUFFER;
+			rsp = NULL;
+		}
+		trace_smb3_open_err(xid, tcon->tid, ses->Suid,
+				    oparms->create_options, oparms->desired_access, rc);
+		if (rc == -EREMCHG) {
+			pr_warn_once("server share %s deleted\n",
+				     tcon->tree_name);
+			tcon->need_reconnect = true;
+		}
+		goto creat_exit;
+	} else if (rsp == NULL) /* unlikely to happen, but safer to check */
+		goto creat_exit;
+	else
+		trace_smb3_open_done(xid, rsp->PersistentFileId, tcon->tid, ses->Suid,
+				     oparms->create_options, oparms->desired_access);
+
+	atomic_inc(&tcon->num_remote_opens);
+	oparms->fid->persistent_fid = rsp->PersistentFileId;
+	oparms->fid->volatile_fid = rsp->VolatileFileId;
+	oparms->fid->access = oparms->desired_access;
+#ifdef CONFIG_CIFS_DEBUG2
+	oparms->fid->mid = le64_to_cpu(rsp->hdr.MessageId);
+#endif /* CIFS_DEBUG2 */
+
+	if (buf) {
+		buf->CreationTime = rsp->CreationTime;
+		buf->LastAccessTime = rsp->LastAccessTime;
+		buf->LastWriteTime = rsp->LastWriteTime;
+		buf->ChangeTime = rsp->ChangeTime;
+		buf->AllocationSize = rsp->AllocationSize;
+		buf->EndOfFile = rsp->EndofFile;
+		buf->Attributes = rsp->FileAttributes;
+		buf->NumberOfLinks = cpu_to_le32(1);
+		buf->DeletePending = 0;
+	}
+
+
+	smb2_parse_contexts(server, rsp, &oparms->fid->epoch,
+			    oparms->fid->lease_key, oplock, buf, posix);
+creat_exit:
+	SMB2_open_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+int
+SMB2_ioctl_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		struct smb_rqst *rqst,
+		u64 persistent_fid, u64 volatile_fid, u32 opcode,
+		char *in_data, u32 indatalen,
+		__u32 max_response_size)
+{
+	struct smb2_ioctl_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int total_len;
+	int rc;
+	char *in_data_buf;
+
+	rc = smb2_ioctl_req_init(opcode, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (indatalen) {
+		/*
+		 * indatalen is usually small at a couple of bytes max, so
+		 * just allocate through generic pool
+		 */
+		in_data_buf = kmemdup(in_data, indatalen, GFP_NOFS);
+		if (!in_data_buf) {
+			cifs_small_buf_release(req);
+			return -ENOMEM;
+		}
+	}
+
+	req->CtlCode = cpu_to_le32(opcode);
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+
+	iov[0].iov_base = (char *)req;
+	/*
+	 * If no input data, the size of ioctl struct in
+	 * protocol spec still includes a 1 byte data buffer,
+	 * but if input data passed to ioctl, we do not
+	 * want to double count this, so we do not send
+	 * the dummy one byte of data in iovec[0] if sending
+	 * input data (in iovec[1]).
+	 */
+	if (indatalen) {
+		req->InputCount = cpu_to_le32(indatalen);
+		/* do not set InputOffset if no input data */
+		req->InputOffset =
+		       cpu_to_le32(offsetof(struct smb2_ioctl_req, Buffer));
+		rqst->rq_nvec = 2;
+		iov[0].iov_len = total_len - 1;
+		iov[1].iov_base = in_data_buf;
+		iov[1].iov_len = indatalen;
+	} else {
+		rqst->rq_nvec = 1;
+		iov[0].iov_len = total_len;
+	}
+
+	req->OutputOffset = 0;
+	req->OutputCount = 0; /* MBZ */
+
+	/*
+	 * In most cases max_response_size is set to 16K (CIFSMaxBufSize)
+	 * We Could increase default MaxOutputResponse, but that could require
+	 * more credits. Windows typically sets this smaller, but for some
+	 * ioctls it may be useful to allow server to send more. No point
+	 * limiting what the server can send as long as fits in one credit
+	 * We can not handle more than CIFS_MAX_BUF_SIZE yet but may want
+	 * to increase this limit up in the future.
+	 * Note that for snapshot queries that servers like Azure expect that
+	 * the first query be minimal size (and just used to get the number/size
+	 * of previous versions) so response size must be specified as EXACTLY
+	 * sizeof(struct snapshot_array) which is 16 when rounded up to multiple
+	 * of eight bytes.  Currently that is the only case where we set max
+	 * response size smaller.
+	 */
+	req->MaxOutputResponse = cpu_to_le32(max_response_size);
+	req->hdr.CreditCharge =
+		cpu_to_le16(DIV_ROUND_UP(max(indatalen, max_response_size),
+					 SMB2_MAX_BUFFER_SIZE));
+	/* always an FSCTL (for now) */
+	req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);
+
+	/* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */
+	if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO)
+		req->hdr.Flags |= SMB2_FLAGS_SIGNED;
+
+	return 0;
+}
+
+void
+SMB2_ioctl_free(struct smb_rqst *rqst)
+{
+	int i;
+	if (rqst && rqst->rq_iov) {
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+		for (i = 1; i < rqst->rq_nvec; i++)
+			if (rqst->rq_iov[i].iov_base != smb2_padding)
+				kfree(rqst->rq_iov[i].iov_base);
+	}
+}
+
+
+/*
+ *	SMB2 IOCTL is used for both IOCTLs and FSCTLs
+ */
+int
+SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
+	   u64 volatile_fid, u32 opcode, char *in_data, u32 indatalen,
+	   u32 max_out_data_len, char **out_data,
+	   u32 *plen /* returned data len */)
+{
+	struct smb_rqst rqst;
+	struct smb2_ioctl_rsp *rsp = NULL;
+	struct cifs_ses *ses;
+	struct TCP_Server_Info *server;
+	struct kvec iov[SMB2_IOCTL_IOV_SIZE];
+	struct kvec rsp_iov = {NULL, 0};
+	int resp_buftype = CIFS_NO_BUFFER;
+	int rc = 0;
+	int flags = 0;
+
+	cifs_dbg(FYI, "SMB2 IOCTL\n");
+
+	if (out_data != NULL)
+		*out_data = NULL;
+
+	/* zero out returned data len, in case of error */
+	if (plen)
+		*plen = 0;
+
+	if (!tcon)
+		return -EIO;
+
+	ses = tcon->ses;
+	if (!ses)
+		return -EIO;
+
+	server = cifs_pick_channel(ses);
+	if (!server)
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = SMB2_IOCTL_IOV_SIZE;
+
+	rc = SMB2_ioctl_init(tcon, server,
+			     &rqst, persistent_fid, volatile_fid, opcode,
+			     in_data, indatalen, max_out_data_len);
+	if (rc)
+		goto ioctl_exit;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags,
+			    &rsp_iov);
+	rsp = (struct smb2_ioctl_rsp *)rsp_iov.iov_base;
+
+	if (rc != 0)
+		trace_smb3_fsctl_err(xid, persistent_fid, tcon->tid,
+				ses->Suid, 0, opcode, rc);
+
+	if ((rc != 0) && (rc != -EINVAL) && (rc != -E2BIG)) {
+		cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
+		goto ioctl_exit;
+	} else if (rc == -EINVAL) {
+		if ((opcode != FSCTL_SRV_COPYCHUNK_WRITE) &&
+		    (opcode != FSCTL_SRV_COPYCHUNK)) {
+			cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
+			goto ioctl_exit;
+		}
+	} else if (rc == -E2BIG) {
+		if (opcode != FSCTL_QUERY_ALLOCATED_RANGES) {
+			cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
+			goto ioctl_exit;
+		}
+	}
+
+	/* check if caller wants to look at return data or just return rc */
+	if ((plen == NULL) || (out_data == NULL))
+		goto ioctl_exit;
+
+	/*
+	 * Although unlikely to be possible for rsp to be null and rc not set,
+	 * adding check below is slightly safer long term (and quiets Coverity
+	 * warning)
+	 */
+	if (rsp == NULL) {
+		rc = -EIO;
+		goto ioctl_exit;
+	}
+
+	*plen = le32_to_cpu(rsp->OutputCount);
+
+	/* We check for obvious errors in the output buffer length and offset */
+	if (*plen == 0)
+		goto ioctl_exit; /* server returned no data */
+	else if (*plen > rsp_iov.iov_len || *plen > 0xFF00) {
+		cifs_tcon_dbg(VFS, "srv returned invalid ioctl length: %d\n", *plen);
+		*plen = 0;
+		rc = -EIO;
+		goto ioctl_exit;
+	}
+
+	if (rsp_iov.iov_len - *plen < le32_to_cpu(rsp->OutputOffset)) {
+		cifs_tcon_dbg(VFS, "Malformed ioctl resp: len %d offset %d\n", *plen,
+			le32_to_cpu(rsp->OutputOffset));
+		*plen = 0;
+		rc = -EIO;
+		goto ioctl_exit;
+	}
+
+	*out_data = kmemdup((char *)rsp + le32_to_cpu(rsp->OutputOffset),
+			    *plen, GFP_KERNEL);
+	if (*out_data == NULL) {
+		rc = -ENOMEM;
+		goto ioctl_exit;
+	}
+
+ioctl_exit:
+	SMB2_ioctl_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+/*
+ *   Individual callers to ioctl worker function follow
+ */
+
+int
+SMB2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
+		     u64 persistent_fid, u64 volatile_fid)
+{
+	int rc;
+	struct  compress_ioctl fsctl_input;
+	char *ret_data = NULL;
+
+	fsctl_input.CompressionState =
+			cpu_to_le16(COMPRESSION_FORMAT_DEFAULT);
+
+	rc = SMB2_ioctl(xid, tcon, persistent_fid, volatile_fid,
+			FSCTL_SET_COMPRESSION,
+			(char *)&fsctl_input /* data input */,
+			2 /* in data len */, CIFSMaxBufSize /* max out data */,
+			&ret_data /* out data */, NULL);
+
+	cifs_dbg(FYI, "set compression rc %d\n", rc);
+
+	return rc;
+}
+
+int
+SMB2_close_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		struct smb_rqst *rqst,
+		u64 persistent_fid, u64 volatile_fid, bool query_attrs)
+{
+	struct smb2_close_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int total_len;
+	int rc;
+
+	rc = smb2_plain_req_init(SMB2_CLOSE, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+	if (query_attrs)
+		req->Flags = SMB2_CLOSE_FLAG_POSTQUERY_ATTRIB;
+	else
+		req->Flags = 0;
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	return 0;
+}
+
+void
+SMB2_close_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov)
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+}
+
+int
+__SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
+	     u64 persistent_fid, u64 volatile_fid,
+	     struct smb2_file_network_open_info *pbuf)
+{
+	struct smb_rqst rqst;
+	struct smb2_close_rsp *rsp = NULL;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int resp_buftype = CIFS_NO_BUFFER;
+	int rc = 0;
+	int flags = 0;
+	bool query_attrs = false;
+
+	cifs_dbg(FYI, "Close\n");
+
+	if (!ses || !server)
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	/* check if need to ask server to return timestamps in close response */
+	if (pbuf)
+		query_attrs = true;
+
+	trace_smb3_close_enter(xid, persistent_fid, tcon->tid, ses->Suid);
+	rc = SMB2_close_init(tcon, server,
+			     &rqst, persistent_fid, volatile_fid,
+			     query_attrs);
+	if (rc)
+		goto close_exit;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	rsp = (struct smb2_close_rsp *)rsp_iov.iov_base;
+
+	if (rc != 0) {
+		cifs_stats_fail_inc(tcon, SMB2_CLOSE_HE);
+		trace_smb3_close_err(xid, persistent_fid, tcon->tid, ses->Suid,
+				     rc);
+		goto close_exit;
+	} else {
+		trace_smb3_close_done(xid, persistent_fid, tcon->tid,
+				      ses->Suid);
+		if (pbuf)
+			memcpy(&pbuf->network_open_info,
+			       &rsp->network_open_info,
+			       sizeof(pbuf->network_open_info));
+	}
+
+	atomic_dec(&tcon->num_remote_opens);
+close_exit:
+	SMB2_close_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp);
+
+	/* retry close in a worker thread if this one is interrupted */
+	if (is_interrupt_error(rc)) {
+		int tmp_rc;
+
+		tmp_rc = smb2_handle_cancelled_close(tcon, persistent_fid,
+						     volatile_fid);
+		if (tmp_rc)
+			cifs_dbg(VFS, "handle cancelled close fid 0x%llx returned error %d\n",
+				 persistent_fid, tmp_rc);
+	}
+	return rc;
+}
+
+int
+SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
+		u64 persistent_fid, u64 volatile_fid)
+{
+	return __SMB2_close(xid, tcon, persistent_fid, volatile_fid, NULL);
+}
+
+int
+smb2_validate_iov(unsigned int offset, unsigned int buffer_length,
+		  struct kvec *iov, unsigned int min_buf_size)
+{
+	unsigned int smb_len = iov->iov_len;
+	char *end_of_smb = smb_len + (char *)iov->iov_base;
+	char *begin_of_buf = offset + (char *)iov->iov_base;
+	char *end_of_buf = begin_of_buf + buffer_length;
+
+
+	if (buffer_length < min_buf_size) {
+		cifs_dbg(VFS, "buffer length %d smaller than minimum size %d\n",
+			 buffer_length, min_buf_size);
+		return -EINVAL;
+	}
+
+	/* check if beyond RFC1001 maximum length */
+	if ((smb_len > 0x7FFFFF) || (buffer_length > 0x7FFFFF)) {
+		cifs_dbg(VFS, "buffer length %d or smb length %d too large\n",
+			 buffer_length, smb_len);
+		return -EINVAL;
+	}
+
+	if ((begin_of_buf > end_of_smb) || (end_of_buf > end_of_smb)) {
+		cifs_dbg(VFS, "Invalid server response, bad offset to data\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * If SMB buffer fields are valid, copy into temporary buffer to hold result.
+ * Caller must free buffer.
+ */
+int
+smb2_validate_and_copy_iov(unsigned int offset, unsigned int buffer_length,
+			   struct kvec *iov, unsigned int minbufsize,
+			   char *data)
+{
+	char *begin_of_buf = offset + (char *)iov->iov_base;
+	int rc;
+
+	if (!data)
+		return -EINVAL;
+
+	rc = smb2_validate_iov(offset, buffer_length, iov, minbufsize);
+	if (rc)
+		return rc;
+
+	memcpy(data, begin_of_buf, minbufsize);
+
+	return 0;
+}
+
+int
+SMB2_query_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		     struct smb_rqst *rqst,
+		     u64 persistent_fid, u64 volatile_fid,
+		     u8 info_class, u8 info_type, u32 additional_info,
+		     size_t output_len, size_t input_len, void *input)
+{
+	struct smb2_query_info_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int total_len;
+	size_t len;
+	int rc;
+
+	if (unlikely(check_add_overflow(input_len, sizeof(*req), &len) ||
+		     len > CIFSMaxBufSize))
+		return -EINVAL;
+
+	rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->InfoType = info_type;
+	req->FileInfoClass = info_class;
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+	req->AdditionalInformation = cpu_to_le32(additional_info);
+
+	req->OutputBufferLength = cpu_to_le32(output_len);
+	if (input_len) {
+		req->InputBufferLength = cpu_to_le32(input_len);
+		/* total_len for smb query request never close to le16 max */
+		req->InputBufferOffset = cpu_to_le16(total_len - 1);
+		memcpy(req->Buffer, input, input_len);
+	}
+
+	iov[0].iov_base = (char *)req;
+	/* 1 for Buffer */
+	iov[0].iov_len = len;
+	return 0;
+}
+
+void
+SMB2_query_info_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov)
+		cifs_buf_release(rqst->rq_iov[0].iov_base); /* request */
+}
+
+static int
+query_info(const unsigned int xid, struct cifs_tcon *tcon,
+	   u64 persistent_fid, u64 volatile_fid, u8 info_class, u8 info_type,
+	   u32 additional_info, size_t output_len, size_t min_len, void **data,
+		u32 *dlen)
+{
+	struct smb_rqst rqst;
+	struct smb2_query_info_rsp *rsp = NULL;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype = CIFS_NO_BUFFER;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server;
+	int flags = 0;
+	bool allocated = false;
+
+	cifs_dbg(FYI, "Query Info\n");
+
+	if (!ses)
+		return -EIO;
+	server = cifs_pick_channel(ses);
+	if (!server)
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = SMB2_query_info_init(tcon, server,
+				  &rqst, persistent_fid, volatile_fid,
+				  info_class, info_type, additional_info,
+				  output_len, 0, NULL);
+	if (rc)
+		goto qinf_exit;
+
+	trace_smb3_query_info_enter(xid, persistent_fid, tcon->tid,
+				    ses->Suid, info_class, (__u32)info_type);
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
+		trace_smb3_query_info_err(xid, persistent_fid, tcon->tid,
+				ses->Suid, info_class, (__u32)info_type, rc);
+		goto qinf_exit;
+	}
+
+	trace_smb3_query_info_done(xid, persistent_fid, tcon->tid,
+				ses->Suid, info_class, (__u32)info_type);
+
+	if (dlen) {
+		*dlen = le32_to_cpu(rsp->OutputBufferLength);
+		if (!*data) {
+			*data = kmalloc(*dlen, GFP_KERNEL);
+			if (!*data) {
+				cifs_tcon_dbg(VFS,
+					"Error %d allocating memory for acl\n",
+					rc);
+				*dlen = 0;
+				rc = -ENOMEM;
+				goto qinf_exit;
+			}
+			allocated = true;
+		}
+	}
+
+	rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset),
+					le32_to_cpu(rsp->OutputBufferLength),
+					&rsp_iov, dlen ? *dlen : min_len, *data);
+	if (rc && allocated) {
+		kfree(*data);
+		*data = NULL;
+		*dlen = 0;
+	}
+
+qinf_exit:
+	SMB2_query_info_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+int SMB2_query_info(const unsigned int xid, struct cifs_tcon *tcon,
+	u64 persistent_fid, u64 volatile_fid, struct smb2_file_all_info *data)
+{
+	return query_info(xid, tcon, persistent_fid, volatile_fid,
+			  FILE_ALL_INFORMATION, SMB2_O_INFO_FILE, 0,
+			  sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
+			  sizeof(struct smb2_file_all_info), (void **)&data,
+			  NULL);
+}
+
+#if 0
+/* currently unused, as now we are doing compounding instead (see smb311_posix_query_path_info) */
+int
+SMB311_posix_query_info(const unsigned int xid, struct cifs_tcon *tcon,
+		u64 persistent_fid, u64 volatile_fid, struct smb311_posix_qinfo *data, u32 *plen)
+{
+	size_t output_len = sizeof(struct smb311_posix_qinfo *) +
+			(sizeof(struct cifs_sid) * 2) + (PATH_MAX * 2);
+	*plen = 0;
+
+	return query_info(xid, tcon, persistent_fid, volatile_fid,
+			  SMB_FIND_FILE_POSIX_INFO, SMB2_O_INFO_FILE, 0,
+			  output_len, sizeof(struct smb311_posix_qinfo), (void **)&data, plen);
+	/* Note caller must free "data" (passed in above). It may be allocated in query_info call */
+}
+#endif
+
+int
+SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
+	       u64 persistent_fid, u64 volatile_fid,
+	       void **data, u32 *plen, u32 extra_info)
+{
+	__u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO |
+				extra_info;
+	*plen = 0;
+
+	return query_info(xid, tcon, persistent_fid, volatile_fid,
+			  0, SMB2_O_INFO_SECURITY, additional_info,
+			  SMB2_MAX_BUFFER_SIZE, MIN_SEC_DESC_LEN, data, plen);
+}
+
+int
+SMB2_get_srv_num(const unsigned int xid, struct cifs_tcon *tcon,
+		 u64 persistent_fid, u64 volatile_fid, __le64 *uniqueid)
+{
+	return query_info(xid, tcon, persistent_fid, volatile_fid,
+			  FILE_INTERNAL_INFORMATION, SMB2_O_INFO_FILE, 0,
+			  sizeof(struct smb2_file_internal_info),
+			  sizeof(struct smb2_file_internal_info),
+			  (void **)&uniqueid, NULL);
+}
+
+/*
+ * CHANGE_NOTIFY Request is sent to get notifications on changes to a directory
+ * See MS-SMB2 2.2.35 and 2.2.36
+ */
+
+static int
+SMB2_notify_init(const unsigned int xid, struct smb_rqst *rqst,
+		 struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		 u64 persistent_fid, u64 volatile_fid,
+		 u32 completion_filter, bool watch_tree)
+{
+	struct smb2_change_notify_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int total_len;
+	int rc;
+
+	rc = smb2_plain_req_init(SMB2_CHANGE_NOTIFY, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+	/* See note 354 of MS-SMB2, 64K max */
+	req->OutputBufferLength =
+		cpu_to_le32(SMB2_MAX_BUFFER_SIZE - MAX_SMB2_HDR_SIZE);
+	req->CompletionFilter = cpu_to_le32(completion_filter);
+	if (watch_tree)
+		req->Flags = cpu_to_le16(SMB2_WATCH_TREE);
+	else
+		req->Flags = 0;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	return 0;
+}
+
+int
+SMB2_change_notify(const unsigned int xid, struct cifs_tcon *tcon,
+		u64 persistent_fid, u64 volatile_fid, bool watch_tree,
+		u32 completion_filter, u32 max_out_data_len, char **out_data,
+		u32 *plen /* returned data len */)
+{
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	struct smb_rqst rqst;
+	struct smb2_change_notify_rsp *smb_rsp;
+	struct kvec iov[1];
+	struct kvec rsp_iov = {NULL, 0};
+	int resp_buftype = CIFS_NO_BUFFER;
+	int flags = 0;
+	int rc = 0;
+
+	cifs_dbg(FYI, "change notify\n");
+	if (!ses || !server)
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	if (plen)
+		*plen = 0;
+
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = SMB2_notify_init(xid, &rqst, tcon, server,
+			      persistent_fid, volatile_fid,
+			      completion_filter, watch_tree);
+	if (rc)
+		goto cnotify_exit;
+
+	trace_smb3_notify_enter(xid, persistent_fid, tcon->tid, ses->Suid,
+				(u8)watch_tree, completion_filter);
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+
+	if (rc != 0) {
+		cifs_stats_fail_inc(tcon, SMB2_CHANGE_NOTIFY_HE);
+		trace_smb3_notify_err(xid, persistent_fid, tcon->tid, ses->Suid,
+				(u8)watch_tree, completion_filter, rc);
+	} else {
+		trace_smb3_notify_done(xid, persistent_fid, tcon->tid,
+			ses->Suid, (u8)watch_tree, completion_filter);
+		/* validate that notify information is plausible */
+		if ((rsp_iov.iov_base == NULL) ||
+		    (rsp_iov.iov_len < sizeof(struct smb2_change_notify_rsp) + 1))
+			goto cnotify_exit;
+
+		smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base;
+
+		smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset),
+				le32_to_cpu(smb_rsp->OutputBufferLength), &rsp_iov,
+				sizeof(struct file_notify_information));
+
+		*out_data = kmemdup((char *)smb_rsp + le16_to_cpu(smb_rsp->OutputBufferOffset),
+				le32_to_cpu(smb_rsp->OutputBufferLength), GFP_KERNEL);
+		if (*out_data == NULL) {
+			rc = -ENOMEM;
+			goto cnotify_exit;
+		} else if (plen)
+			*plen = le32_to_cpu(smb_rsp->OutputBufferLength);
+	}
+
+ cnotify_exit:
+	if (rqst.rq_iov)
+		cifs_small_buf_release(rqst.rq_iov[0].iov_base); /* request */
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+
+
+
+/*
+ * This is a no-op for now. We're not really interested in the reply, but
+ * rather in the fact that the server sent one and that server->lstrp
+ * gets updated.
+ *
+ * FIXME: maybe we should consider checking that the reply matches request?
+ */
+static void
+smb2_echo_callback(struct mid_q_entry *mid)
+{
+	struct TCP_Server_Info *server = mid->callback_data;
+	struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
+
+	if (mid->mid_state == MID_RESPONSE_RECEIVED
+	    || mid->mid_state == MID_RESPONSE_MALFORMED) {
+		credits.value = le16_to_cpu(rsp->hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
+	}
+
+	release_mid(mid);
+	add_credits(server, &credits, CIFS_ECHO_OP);
+}
+
+void smb2_reconnect_server(struct work_struct *work)
+{
+	struct TCP_Server_Info *server = container_of(work,
+					struct TCP_Server_Info, reconnect.work);
+	struct TCP_Server_Info *pserver;
+	struct cifs_ses *ses, *ses2;
+	struct cifs_tcon *tcon, *tcon2;
+	struct list_head tmp_list, tmp_ses_list;
+	bool tcon_exist = false, ses_exist = false;
+	bool tcon_selected = false;
+	int rc;
+	bool resched = false;
+
+	/* If server is a channel, select the primary channel */
+	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
+
+	/* Prevent simultaneous reconnects that can corrupt tcon->rlist list */
+	mutex_lock(&pserver->reconnect_mutex);
+
+	INIT_LIST_HEAD(&tmp_list);
+	INIT_LIST_HEAD(&tmp_ses_list);
+	cifs_dbg(FYI, "Reconnecting tcons and channels\n");
+
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+		spin_lock(&ses->ses_lock);
+		if (ses->ses_status == SES_EXITING) {
+			spin_unlock(&ses->ses_lock);
+			continue;
+		}
+		spin_unlock(&ses->ses_lock);
+
+		tcon_selected = false;
+
+		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
+			if (tcon->need_reconnect || tcon->need_reopen_files) {
+				tcon->tc_count++;
+				list_add_tail(&tcon->rlist, &tmp_list);
+				tcon_selected = tcon_exist = true;
+			}
+		}
+		/*
+		 * IPC has the same lifetime as its session and uses its
+		 * refcount.
+		 */
+		if (ses->tcon_ipc && ses->tcon_ipc->need_reconnect) {
+			list_add_tail(&ses->tcon_ipc->rlist, &tmp_list);
+			tcon_selected = tcon_exist = true;
+			ses->ses_count++;
+		}
+		/*
+		 * handle the case where channel needs to reconnect
+		 * binding session, but tcon is healthy (some other channel
+		 * is active)
+		 */
+		spin_lock(&ses->chan_lock);
+		if (!tcon_selected && cifs_chan_needs_reconnect(ses, server)) {
+			list_add_tail(&ses->rlist, &tmp_ses_list);
+			ses_exist = true;
+			ses->ses_count++;
+		}
+		spin_unlock(&ses->chan_lock);
+	}
+	/*
+	 * Get the reference to server struct to be sure that the last call of
+	 * cifs_put_tcon() in the loop below won't release the server pointer.
+	 */
+	if (tcon_exist || ses_exist)
+		server->srv_count++;
+
+	spin_unlock(&cifs_tcp_ses_lock);
+
+	list_for_each_entry_safe(tcon, tcon2, &tmp_list, rlist) {
+		rc = smb2_reconnect(SMB2_INTERNAL_CMD, tcon, server);
+		if (!rc)
+			cifs_reopen_persistent_handles(tcon);
+		else
+			resched = true;
+		list_del_init(&tcon->rlist);
+		if (tcon->ipc)
+			cifs_put_smb_ses(tcon->ses);
+		else
+			cifs_put_tcon(tcon);
+	}
+
+	if (!ses_exist)
+		goto done;
+
+	/* allocate a dummy tcon struct used for reconnect */
+	tcon = tconInfoAlloc();
+	if (!tcon) {
+		resched = true;
+		list_for_each_entry_safe(ses, ses2, &tmp_ses_list, rlist) {
+			list_del_init(&ses->rlist);
+			cifs_put_smb_ses(ses);
+		}
+		goto done;
+	}
+
+	tcon->status = TID_GOOD;
+	tcon->retry = false;
+	tcon->need_reconnect = false;
+
+	/* now reconnect sessions for necessary channels */
+	list_for_each_entry_safe(ses, ses2, &tmp_ses_list, rlist) {
+		tcon->ses = ses;
+		rc = smb2_reconnect(SMB2_INTERNAL_CMD, tcon, server);
+		if (rc)
+			resched = true;
+		list_del_init(&ses->rlist);
+		cifs_put_smb_ses(ses);
+	}
+	tconInfoFree(tcon);
+
+done:
+	cifs_dbg(FYI, "Reconnecting tcons and channels finished\n");
+	if (resched)
+		queue_delayed_work(cifsiod_wq, &server->reconnect, 2 * HZ);
+	mutex_unlock(&pserver->reconnect_mutex);
+
+	/* now we can safely release srv struct */
+	if (tcon_exist || ses_exist)
+		cifs_put_tcp_session(server, 1);
+}
+
+int
+SMB2_echo(struct TCP_Server_Info *server)
+{
+	struct smb2_echo_req *req;
+	int rc = 0;
+	struct kvec iov[1];
+	struct smb_rqst rqst = { .rq_iov = iov,
+				 .rq_nvec = 1 };
+	unsigned int total_len;
+
+	cifs_dbg(FYI, "In echo request for conn_id %lld\n", server->conn_id);
+
+	spin_lock(&server->srv_lock);
+	if (server->ops->need_neg &&
+	    server->ops->need_neg(server)) {
+		spin_unlock(&server->srv_lock);
+		/* No need to send echo on newly established connections */
+		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
+		return rc;
+	}
+	spin_unlock(&server->srv_lock);
+
+	rc = smb2_plain_req_init(SMB2_ECHO, NULL, server,
+				 (void **)&req, &total_len);
+	if (rc)
+		return rc;
+
+	req->hdr.CreditRequest = cpu_to_le16(1);
+
+	iov[0].iov_len = total_len;
+	iov[0].iov_base = (char *)req;
+
+	rc = cifs_call_async(server, &rqst, NULL, smb2_echo_callback, NULL,
+			     server, CIFS_ECHO_OP, NULL);
+	if (rc)
+		cifs_dbg(FYI, "Echo request failed: %d\n", rc);
+
+	cifs_small_buf_release(req);
+	return rc;
+}
+
+void
+SMB2_flush_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov)
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+}
+
+int
+SMB2_flush_init(const unsigned int xid, struct smb_rqst *rqst,
+		struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		u64 persistent_fid, u64 volatile_fid)
+{
+	struct smb2_flush_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int total_len;
+	int rc;
+
+	rc = smb2_plain_req_init(SMB2_FLUSH, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	return 0;
+}
+
+int
+SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
+	   u64 volatile_fid)
+{
+	struct cifs_ses *ses = tcon->ses;
+	struct smb_rqst rqst;
+	struct kvec iov[1];
+	struct kvec rsp_iov = {NULL, 0};
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	int resp_buftype = CIFS_NO_BUFFER;
+	int flags = 0;
+	int rc = 0;
+
+	cifs_dbg(FYI, "flush\n");
+	if (!ses || !(ses->server))
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = SMB2_flush_init(xid, &rqst, tcon, server,
+			     persistent_fid, volatile_fid);
+	if (rc)
+		goto flush_exit;
+
+	trace_smb3_flush_enter(xid, persistent_fid, tcon->tid, ses->Suid);
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+
+	if (rc != 0) {
+		cifs_stats_fail_inc(tcon, SMB2_FLUSH_HE);
+		trace_smb3_flush_err(xid, persistent_fid, tcon->tid, ses->Suid,
+				     rc);
+	} else
+		trace_smb3_flush_done(xid, persistent_fid, tcon->tid,
+				      ses->Suid);
+
+ flush_exit:
+	SMB2_flush_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+static inline bool smb3_use_rdma_offload(struct cifs_io_parms *io_parms)
+{
+	struct TCP_Server_Info *server = io_parms->server;
+	struct cifs_tcon *tcon = io_parms->tcon;
+
+	/* we can only offload if we're connected */
+	if (!server || !tcon)
+		return false;
+
+	/* we can only offload on an rdma connection */
+	if (!server->rdma || !server->smbd_conn)
+		return false;
+
+	/* we don't support signed offload yet */
+	if (server->sign)
+		return false;
+
+	/* we don't support encrypted offload yet */
+	if (smb3_encryption_required(tcon))
+		return false;
+
+	/* offload also has its overhead, so only do it if desired */
+	if (io_parms->length < server->smbd_conn->rdma_readwrite_threshold)
+		return false;
+
+	return true;
+}
+#endif /* CONFIG_CIFS_SMB_DIRECT */
+
+/*
+ * To form a chain of read requests, any read requests after the first should
+ * have the end_of_chain boolean set to true.
+ */
+static int
+smb2_new_read_req(void **buf, unsigned int *total_len,
+	struct cifs_io_parms *io_parms, struct cifs_readdata *rdata,
+	unsigned int remaining_bytes, int request_type)
+{
+	int rc = -EACCES;
+	struct smb2_read_req *req = NULL;
+	struct smb2_hdr *shdr;
+	struct TCP_Server_Info *server = io_parms->server;
+
+	rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, server,
+				 (void **) &req, total_len);
+	if (rc)
+		return rc;
+
+	if (server == NULL)
+		return -ECONNABORTED;
+
+	shdr = &req->hdr;
+	shdr->Id.SyncId.ProcessId = cpu_to_le32(io_parms->pid);
+
+	req->PersistentFileId = io_parms->persistent_fid;
+	req->VolatileFileId = io_parms->volatile_fid;
+	req->ReadChannelInfoOffset = 0; /* reserved */
+	req->ReadChannelInfoLength = 0; /* reserved */
+	req->Channel = 0; /* reserved */
+	req->MinimumCount = 0;
+	req->Length = cpu_to_le32(io_parms->length);
+	req->Offset = cpu_to_le64(io_parms->offset);
+
+	trace_smb3_read_enter(0 /* xid */,
+			io_parms->persistent_fid,
+			io_parms->tcon->tid, io_parms->tcon->ses->Suid,
+			io_parms->offset, io_parms->length);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	/*
+	 * If we want to do a RDMA write, fill in and append
+	 * smbd_buffer_descriptor_v1 to the end of read request
+	 */
+	if (smb3_use_rdma_offload(io_parms)) {
+		struct smbd_buffer_descriptor_v1 *v1;
+		bool need_invalidate = server->dialect == SMB30_PROT_ID;
+
+		rdata->mr = smbd_register_mr(
+				server->smbd_conn, rdata->pages,
+				rdata->nr_pages, rdata->page_offset,
+				rdata->tailsz, true, need_invalidate);
+		if (!rdata->mr)
+			return -EAGAIN;
+
+		req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
+		if (need_invalidate)
+			req->Channel = SMB2_CHANNEL_RDMA_V1;
+		req->ReadChannelInfoOffset =
+			cpu_to_le16(offsetof(struct smb2_read_req, Buffer));
+		req->ReadChannelInfoLength =
+			cpu_to_le16(sizeof(struct smbd_buffer_descriptor_v1));
+		v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0];
+		v1->offset = cpu_to_le64(rdata->mr->mr->iova);
+		v1->token = cpu_to_le32(rdata->mr->mr->rkey);
+		v1->length = cpu_to_le32(rdata->mr->mr->length);
+
+		*total_len += sizeof(*v1) - 1;
+	}
+#endif
+	if (request_type & CHAINED_REQUEST) {
+		if (!(request_type & END_OF_CHAIN)) {
+			/* next 8-byte aligned request */
+			*total_len = ALIGN(*total_len, 8);
+			shdr->NextCommand = cpu_to_le32(*total_len);
+		} else /* END_OF_CHAIN */
+			shdr->NextCommand = 0;
+		if (request_type & RELATED_REQUEST) {
+			shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS;
+			/*
+			 * Related requests use info from previous read request
+			 * in chain.
+			 */
+			shdr->SessionId = cpu_to_le64(0xFFFFFFFFFFFFFFFF);
+			shdr->Id.SyncId.TreeId = cpu_to_le32(0xFFFFFFFF);
+			req->PersistentFileId = (u64)-1;
+			req->VolatileFileId = (u64)-1;
+		}
+	}
+	if (remaining_bytes > io_parms->length)
+		req->RemainingBytes = cpu_to_le32(remaining_bytes);
+	else
+		req->RemainingBytes = 0;
+
+	*buf = req;
+	return rc;
+}
+
+static void
+smb2_readv_callback(struct mid_q_entry *mid)
+{
+	struct cifs_readdata *rdata = mid->callback_data;
+	struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink);
+	struct TCP_Server_Info *server = rdata->server;
+	struct smb2_hdr *shdr =
+				(struct smb2_hdr *)rdata->iov[0].iov_base;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
+	struct smb_rqst rqst = { .rq_iov = &rdata->iov[1],
+				 .rq_nvec = 1, };
+
+	if (rdata->got_bytes) {
+		rqst.rq_pages = rdata->pages;
+		rqst.rq_offset = rdata->page_offset;
+		rqst.rq_npages = rdata->nr_pages;
+		rqst.rq_pagesz = rdata->pagesz;
+		rqst.rq_tailsz = rdata->tailsz;
+	}
+
+	WARN_ONCE(rdata->server != mid->server,
+		  "rdata server %p != mid server %p",
+		  rdata->server, mid->server);
+
+	cifs_dbg(FYI, "%s: mid=%llu state=%d result=%d bytes=%u\n",
+		 __func__, mid->mid, mid->mid_state, rdata->result,
+		 rdata->bytes);
+
+	switch (mid->mid_state) {
+	case MID_RESPONSE_RECEIVED:
+		credits.value = le16_to_cpu(shdr->CreditRequest);
+		credits.instance = server->reconnect_instance;
+		/* result already set, check signature */
+		if (server->sign && !mid->decrypted) {
+			int rc;
+
+			rc = smb2_verify_signature(&rqst, server);
+			if (rc)
+				cifs_tcon_dbg(VFS, "SMB signature verification returned error = %d\n",
+					 rc);
+		}
+		/* FIXME: should this be counted toward the initiating task? */
+		task_io_account_read(rdata->got_bytes);
+		cifs_stats_bytes_read(tcon, rdata->got_bytes);
+		break;
+	case MID_REQUEST_SUBMITTED:
+	case MID_RETRY_NEEDED:
+		rdata->result = -EAGAIN;
+		if (server->sign && rdata->got_bytes)
+			/* reset bytes number since we can not check a sign */
+			rdata->got_bytes = 0;
+		/* FIXME: should this be counted toward the initiating task? */
+		task_io_account_read(rdata->got_bytes);
+		cifs_stats_bytes_read(tcon, rdata->got_bytes);
+		break;
+	case MID_RESPONSE_MALFORMED:
+		credits.value = le16_to_cpu(shdr->CreditRequest);
+		credits.instance = server->reconnect_instance;
+		fallthrough;
+	default:
+		rdata->result = -EIO;
+	}
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	/*
+	 * If this rdata has a memmory registered, the MR can be freed
+	 * MR needs to be freed as soon as I/O finishes to prevent deadlock
+	 * because they have limited number and are used for future I/Os
+	 */
+	if (rdata->mr) {
+		smbd_deregister_mr(rdata->mr);
+		rdata->mr = NULL;
+	}
+#endif
+	if (rdata->result && rdata->result != -ENODATA) {
+		cifs_stats_fail_inc(tcon, SMB2_READ_HE);
+		trace_smb3_read_err(0 /* xid */,
+				    rdata->cfile->fid.persistent_fid,
+				    tcon->tid, tcon->ses->Suid, rdata->offset,
+				    rdata->bytes, rdata->result);
+	} else
+		trace_smb3_read_done(0 /* xid */,
+				     rdata->cfile->fid.persistent_fid,
+				     tcon->tid, tcon->ses->Suid,
+				     rdata->offset, rdata->got_bytes);
+
+	queue_work(cifsiod_wq, &rdata->work);
+	release_mid(mid);
+	add_credits(server, &credits, 0);
+}
+
+/* smb2_async_readv - send an async read, and set up mid to handle result */
+int
+smb2_async_readv(struct cifs_readdata *rdata)
+{
+	int rc, flags = 0;
+	char *buf;
+	struct smb2_hdr *shdr;
+	struct cifs_io_parms io_parms;
+	struct smb_rqst rqst = { .rq_iov = rdata->iov,
+				 .rq_nvec = 1 };
+	struct TCP_Server_Info *server;
+	struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink);
+	unsigned int total_len;
+	int credit_request;
+
+	cifs_dbg(FYI, "%s: offset=%llu bytes=%u\n",
+		 __func__, rdata->offset, rdata->bytes);
+
+	if (!rdata->server)
+		rdata->server = cifs_pick_channel(tcon->ses);
+
+	io_parms.tcon = tlink_tcon(rdata->cfile->tlink);
+	io_parms.server = server = rdata->server;
+	io_parms.offset = rdata->offset;
+	io_parms.length = rdata->bytes;
+	io_parms.persistent_fid = rdata->cfile->fid.persistent_fid;
+	io_parms.volatile_fid = rdata->cfile->fid.volatile_fid;
+	io_parms.pid = rdata->pid;
+
+	rc = smb2_new_read_req(
+		(void **) &buf, &total_len, &io_parms, rdata, 0, 0);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(io_parms.tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	rdata->iov[0].iov_base = buf;
+	rdata->iov[0].iov_len = total_len;
+
+	shdr = (struct smb2_hdr *)buf;
+
+	if (rdata->credits.value > 0) {
+		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
+						SMB2_MAX_BUFFER_SIZE));
+		credit_request = le16_to_cpu(shdr->CreditCharge) + 8;
+		if (server->credits >= server->max_credits)
+			shdr->CreditRequest = cpu_to_le16(0);
+		else
+			shdr->CreditRequest = cpu_to_le16(
+				min_t(int, server->max_credits -
+						server->credits, credit_request));
+
+		rc = adjust_credits(server, &rdata->credits, rdata->bytes);
+		if (rc)
+			goto async_readv_out;
+
+		flags |= CIFS_HAS_CREDITS;
+	}
+
+	kref_get(&rdata->refcount);
+	rc = cifs_call_async(server, &rqst,
+			     cifs_readv_receive, smb2_readv_callback,
+			     smb3_handle_read_data, rdata, flags,
+			     &rdata->credits);
+	if (rc) {
+		kref_put(&rdata->refcount, cifs_readdata_release);
+		cifs_stats_fail_inc(io_parms.tcon, SMB2_READ_HE);
+		trace_smb3_read_err(0 /* xid */, io_parms.persistent_fid,
+				    io_parms.tcon->tid,
+				    io_parms.tcon->ses->Suid,
+				    io_parms.offset, io_parms.length, rc);
+	}
+
+async_readv_out:
+	cifs_small_buf_release(buf);
+	return rc;
+}
+
+int
+SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
+	  unsigned int *nbytes, char **buf, int *buf_type)
+{
+	struct smb_rqst rqst;
+	int resp_buftype, rc;
+	struct smb2_read_req *req = NULL;
+	struct smb2_read_rsp *rsp = NULL;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	unsigned int total_len;
+	int flags = CIFS_LOG_ERROR;
+	struct cifs_ses *ses = io_parms->tcon->ses;
+
+	if (!io_parms->server)
+		io_parms->server = cifs_pick_channel(io_parms->tcon->ses);
+
+	*nbytes = 0;
+	rc = smb2_new_read_req((void **)&req, &total_len, io_parms, NULL, 0, 0);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(io_parms->tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, io_parms->server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	rsp = (struct smb2_read_rsp *)rsp_iov.iov_base;
+
+	if (rc) {
+		if (rc != -ENODATA) {
+			cifs_stats_fail_inc(io_parms->tcon, SMB2_READ_HE);
+			cifs_dbg(VFS, "Send error in read = %d\n", rc);
+			trace_smb3_read_err(xid,
+					    req->PersistentFileId,
+					    io_parms->tcon->tid, ses->Suid,
+					    io_parms->offset, io_parms->length,
+					    rc);
+		} else
+			trace_smb3_read_done(xid, req->PersistentFileId, io_parms->tcon->tid,
+					     ses->Suid, io_parms->offset, 0);
+		free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+		cifs_small_buf_release(req);
+		return rc == -ENODATA ? 0 : rc;
+	} else
+		trace_smb3_read_done(xid,
+				    req->PersistentFileId,
+				    io_parms->tcon->tid, ses->Suid,
+				    io_parms->offset, io_parms->length);
+
+	cifs_small_buf_release(req);
+
+	*nbytes = le32_to_cpu(rsp->DataLength);
+	if ((*nbytes > CIFS_MAX_MSGSIZE) ||
+	    (*nbytes > io_parms->length)) {
+		cifs_dbg(FYI, "bad length %d for count %d\n",
+			 *nbytes, io_parms->length);
+		rc = -EIO;
+		*nbytes = 0;
+	}
+
+	if (*buf) {
+		memcpy(*buf, (char *)rsp + rsp->DataOffset, *nbytes);
+		free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	} else if (resp_buftype != CIFS_NO_BUFFER) {
+		*buf = rsp_iov.iov_base;
+		if (resp_buftype == CIFS_SMALL_BUFFER)
+			*buf_type = CIFS_SMALL_BUFFER;
+		else if (resp_buftype == CIFS_LARGE_BUFFER)
+			*buf_type = CIFS_LARGE_BUFFER;
+	}
+	return rc;
+}
+
+/*
+ * Check the mid_state and signature on received buffer (if any), and queue the
+ * workqueue completion task.
+ */
+static void
+smb2_writev_callback(struct mid_q_entry *mid)
+{
+	struct cifs_writedata *wdata = mid->callback_data;
+	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
+	struct TCP_Server_Info *server = wdata->server;
+	unsigned int written;
+	struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
+
+	WARN_ONCE(wdata->server != mid->server,
+		  "wdata server %p != mid server %p",
+		  wdata->server, mid->server);
+
+	switch (mid->mid_state) {
+	case MID_RESPONSE_RECEIVED:
+		credits.value = le16_to_cpu(rsp->hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
+		wdata->result = smb2_check_receive(mid, server, 0);
+		if (wdata->result != 0)
+			break;
+
+		written = le32_to_cpu(rsp->DataLength);
+		/*
+		 * Mask off high 16 bits when bytes written as returned
+		 * by the server is greater than bytes requested by the
+		 * client. OS/2 servers are known to set incorrect
+		 * CountHigh values.
+		 */
+		if (written > wdata->bytes)
+			written &= 0xFFFF;
+
+		if (written < wdata->bytes)
+			wdata->result = -ENOSPC;
+		else
+			wdata->bytes = written;
+		break;
+	case MID_REQUEST_SUBMITTED:
+	case MID_RETRY_NEEDED:
+		wdata->result = -EAGAIN;
+		break;
+	case MID_RESPONSE_MALFORMED:
+		credits.value = le16_to_cpu(rsp->hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
+		fallthrough;
+	default:
+		wdata->result = -EIO;
+		break;
+	}
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	/*
+	 * If this wdata has a memory registered, the MR can be freed
+	 * The number of MRs available is limited, it's important to recover
+	 * used MR as soon as I/O is finished. Hold MR longer in the later
+	 * I/O process can possibly result in I/O deadlock due to lack of MR
+	 * to send request on I/O retry
+	 */
+	if (wdata->mr) {
+		smbd_deregister_mr(wdata->mr);
+		wdata->mr = NULL;
+	}
+#endif
+	if (wdata->result) {
+		cifs_stats_fail_inc(tcon, SMB2_WRITE_HE);
+		trace_smb3_write_err(0 /* no xid */,
+				     wdata->cfile->fid.persistent_fid,
+				     tcon->tid, tcon->ses->Suid, wdata->offset,
+				     wdata->bytes, wdata->result);
+		if (wdata->result == -ENOSPC)
+			pr_warn_once("Out of space writing to %s\n",
+				     tcon->tree_name);
+	} else
+		trace_smb3_write_done(0 /* no xid */,
+				      wdata->cfile->fid.persistent_fid,
+				      tcon->tid, tcon->ses->Suid,
+				      wdata->offset, wdata->bytes);
+
+	queue_work(cifsiod_wq, &wdata->work);
+	release_mid(mid);
+	add_credits(server, &credits, 0);
+}
+
+/* smb2_async_writev - send an async write, and set up mid to handle result */
+int
+smb2_async_writev(struct cifs_writedata *wdata,
+		  void (*release)(struct kref *kref))
+{
+	int rc = -EACCES, flags = 0;
+	struct smb2_write_req *req = NULL;
+	struct smb2_hdr *shdr;
+	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
+	struct TCP_Server_Info *server = wdata->server;
+	struct kvec iov[1];
+	struct smb_rqst rqst = { };
+	unsigned int total_len;
+	struct cifs_io_parms _io_parms;
+	struct cifs_io_parms *io_parms = NULL;
+	int credit_request;
+
+	if (!wdata->server)
+		server = wdata->server = cifs_pick_channel(tcon->ses);
+
+	/*
+	 * in future we may get cifs_io_parms passed in from the caller,
+	 * but for now we construct it here...
+	 */
+	_io_parms = (struct cifs_io_parms) {
+		.tcon = tcon,
+		.server = server,
+		.offset = wdata->offset,
+		.length = wdata->bytes,
+		.persistent_fid = wdata->cfile->fid.persistent_fid,
+		.volatile_fid = wdata->cfile->fid.volatile_fid,
+		.pid = wdata->pid,
+	};
+	io_parms = &_io_parms;
+
+	rc = smb2_plain_req_init(SMB2_WRITE, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	shdr = (struct smb2_hdr *)req;
+	shdr->Id.SyncId.ProcessId = cpu_to_le32(io_parms->pid);
+
+	req->PersistentFileId = io_parms->persistent_fid;
+	req->VolatileFileId = io_parms->volatile_fid;
+	req->WriteChannelInfoOffset = 0;
+	req->WriteChannelInfoLength = 0;
+	req->Channel = 0;
+	req->Offset = cpu_to_le64(io_parms->offset);
+	req->DataOffset = cpu_to_le16(
+				offsetof(struct smb2_write_req, Buffer));
+	req->RemainingBytes = 0;
+
+	trace_smb3_write_enter(0 /* xid */,
+			       io_parms->persistent_fid,
+			       io_parms->tcon->tid,
+			       io_parms->tcon->ses->Suid,
+			       io_parms->offset,
+			       io_parms->length);
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	/*
+	 * If we want to do a server RDMA read, fill in and append
+	 * smbd_buffer_descriptor_v1 to the end of write request
+	 */
+	if (smb3_use_rdma_offload(io_parms)) {
+		struct smbd_buffer_descriptor_v1 *v1;
+		bool need_invalidate = server->dialect == SMB30_PROT_ID;
+
+		wdata->mr = smbd_register_mr(
+				server->smbd_conn, wdata->pages,
+				wdata->nr_pages, wdata->page_offset,
+				wdata->tailsz, false, need_invalidate);
+		if (!wdata->mr) {
+			rc = -EAGAIN;
+			goto async_writev_out;
+		}
+		req->Length = 0;
+		req->DataOffset = 0;
+		if (wdata->nr_pages > 1)
+			req->RemainingBytes =
+				cpu_to_le32(
+					(wdata->nr_pages - 1) * wdata->pagesz -
+					wdata->page_offset + wdata->tailsz
+				);
+		else
+			req->RemainingBytes = cpu_to_le32(wdata->tailsz);
+		req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
+		if (need_invalidate)
+			req->Channel = SMB2_CHANNEL_RDMA_V1;
+		req->WriteChannelInfoOffset =
+			cpu_to_le16(offsetof(struct smb2_write_req, Buffer));
+		req->WriteChannelInfoLength =
+			cpu_to_le16(sizeof(struct smbd_buffer_descriptor_v1));
+		v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0];
+		v1->offset = cpu_to_le64(wdata->mr->mr->iova);
+		v1->token = cpu_to_le32(wdata->mr->mr->rkey);
+		v1->length = cpu_to_le32(wdata->mr->mr->length);
+	}
+#endif
+	iov[0].iov_len = total_len - 1;
+	iov[0].iov_base = (char *)req;
+
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+	rqst.rq_pages = wdata->pages;
+	rqst.rq_offset = wdata->page_offset;
+	rqst.rq_npages = wdata->nr_pages;
+	rqst.rq_pagesz = wdata->pagesz;
+	rqst.rq_tailsz = wdata->tailsz;
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	if (wdata->mr) {
+		iov[0].iov_len += sizeof(struct smbd_buffer_descriptor_v1);
+		rqst.rq_npages = 0;
+	}
+#endif
+	cifs_dbg(FYI, "async write at %llu %u bytes\n",
+		 io_parms->offset, io_parms->length);
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+	/* For RDMA read, I/O size is in RemainingBytes not in Length */
+	if (!wdata->mr)
+		req->Length = cpu_to_le32(io_parms->length);
+#else
+	req->Length = cpu_to_le32(io_parms->length);
+#endif
+
+	if (wdata->credits.value > 0) {
+		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
+						    SMB2_MAX_BUFFER_SIZE));
+		credit_request = le16_to_cpu(shdr->CreditCharge) + 8;
+		if (server->credits >= server->max_credits)
+			shdr->CreditRequest = cpu_to_le16(0);
+		else
+			shdr->CreditRequest = cpu_to_le16(
+				min_t(int, server->max_credits -
+						server->credits, credit_request));
+
+		rc = adjust_credits(server, &wdata->credits, io_parms->length);
+		if (rc)
+			goto async_writev_out;
+
+		flags |= CIFS_HAS_CREDITS;
+	}
+
+	kref_get(&wdata->refcount);
+	rc = cifs_call_async(server, &rqst, NULL, smb2_writev_callback, NULL,
+			     wdata, flags, &wdata->credits);
+
+	if (rc) {
+		trace_smb3_write_err(0 /* no xid */,
+				     io_parms->persistent_fid,
+				     io_parms->tcon->tid,
+				     io_parms->tcon->ses->Suid,
+				     io_parms->offset,
+				     io_parms->length,
+				     rc);
+		kref_put(&wdata->refcount, release);
+		cifs_stats_fail_inc(tcon, SMB2_WRITE_HE);
+	}
+
+async_writev_out:
+	cifs_small_buf_release(req);
+	return rc;
+}
+
+/*
+ * SMB2_write function gets iov pointer to kvec array with n_vec as a length.
+ * The length field from io_parms must be at least 1 and indicates a number of
+ * elements with data to write that begins with position 1 in iov array. All
+ * data length is specified by count.
+ */
+int
+SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
+	   unsigned int *nbytes, struct kvec *iov, int n_vec)
+{
+	struct smb_rqst rqst;
+	int rc = 0;
+	struct smb2_write_req *req = NULL;
+	struct smb2_write_rsp *rsp = NULL;
+	int resp_buftype;
+	struct kvec rsp_iov;
+	int flags = 0;
+	unsigned int total_len;
+	struct TCP_Server_Info *server;
+
+	*nbytes = 0;
+
+	if (n_vec < 1)
+		return rc;
+
+	if (!io_parms->server)
+		io_parms->server = cifs_pick_channel(io_parms->tcon->ses);
+	server = io_parms->server;
+	if (server == NULL)
+		return -ECONNABORTED;
+
+	rc = smb2_plain_req_init(SMB2_WRITE, io_parms->tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(io_parms->tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	req->hdr.Id.SyncId.ProcessId = cpu_to_le32(io_parms->pid);
+
+	req->PersistentFileId = io_parms->persistent_fid;
+	req->VolatileFileId = io_parms->volatile_fid;
+	req->WriteChannelInfoOffset = 0;
+	req->WriteChannelInfoLength = 0;
+	req->Channel = 0;
+	req->Length = cpu_to_le32(io_parms->length);
+	req->Offset = cpu_to_le64(io_parms->offset);
+	req->DataOffset = cpu_to_le16(
+				offsetof(struct smb2_write_req, Buffer));
+	req->RemainingBytes = 0;
+
+	trace_smb3_write_enter(xid, io_parms->persistent_fid,
+		io_parms->tcon->tid, io_parms->tcon->ses->Suid,
+		io_parms->offset, io_parms->length);
+
+	iov[0].iov_base = (char *)req;
+	/* 1 for Buffer */
+	iov[0].iov_len = total_len - 1;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = n_vec + 1;
+
+	rc = cifs_send_recv(xid, io_parms->tcon->ses, server,
+			    &rqst,
+			    &resp_buftype, flags, &rsp_iov);
+	rsp = (struct smb2_write_rsp *)rsp_iov.iov_base;
+
+	if (rc) {
+		trace_smb3_write_err(xid,
+				     req->PersistentFileId,
+				     io_parms->tcon->tid,
+				     io_parms->tcon->ses->Suid,
+				     io_parms->offset, io_parms->length, rc);
+		cifs_stats_fail_inc(io_parms->tcon, SMB2_WRITE_HE);
+		cifs_dbg(VFS, "Send error in write = %d\n", rc);
+	} else {
+		*nbytes = le32_to_cpu(rsp->DataLength);
+		trace_smb3_write_done(xid,
+				      req->PersistentFileId,
+				      io_parms->tcon->tid,
+				      io_parms->tcon->ses->Suid,
+				      io_parms->offset, *nbytes);
+	}
+
+	cifs_small_buf_release(req);
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+int posix_info_sid_size(const void *beg, const void *end)
+{
+	size_t subauth;
+	int total;
+
+	if (beg + 1 > end)
+		return -1;
+
+	subauth = *(u8 *)(beg+1);
+	if (subauth < 1 || subauth > 15)
+		return -1;
+
+	total = 1 + 1 + 6 + 4*subauth;
+	if (beg + total > end)
+		return -1;
+
+	return total;
+}
+
+int posix_info_parse(const void *beg, const void *end,
+		     struct smb2_posix_info_parsed *out)
+
+{
+	int total_len = 0;
+	int owner_len, group_len;
+	int name_len;
+	const void *owner_sid;
+	const void *group_sid;
+	const void *name;
+
+	/* if no end bound given, assume payload to be correct */
+	if (!end) {
+		const struct smb2_posix_info *p = beg;
+
+		end = beg + le32_to_cpu(p->NextEntryOffset);
+		/* last element will have a 0 offset, pick a sensible bound */
+		if (end == beg)
+			end += 0xFFFF;
+	}
+
+	/* check base buf */
+	if (beg + sizeof(struct smb2_posix_info) > end)
+		return -1;
+	total_len = sizeof(struct smb2_posix_info);
+
+	/* check owner sid */
+	owner_sid = beg + total_len;
+	owner_len = posix_info_sid_size(owner_sid, end);
+	if (owner_len < 0)
+		return -1;
+	total_len += owner_len;
+
+	/* check group sid */
+	group_sid = beg + total_len;
+	group_len = posix_info_sid_size(group_sid, end);
+	if (group_len < 0)
+		return -1;
+	total_len += group_len;
+
+	/* check name len */
+	if (beg + total_len + 4 > end)
+		return -1;
+	name_len = le32_to_cpu(*(__le32 *)(beg + total_len));
+	if (name_len < 1 || name_len > 0xFFFF)
+		return -1;
+	total_len += 4;
+
+	/* check name */
+	name = beg + total_len;
+	if (name + name_len > end)
+		return -1;
+	total_len += name_len;
+
+	if (out) {
+		out->base = beg;
+		out->size = total_len;
+		out->name_len = name_len;
+		out->name = name;
+		memcpy(&out->owner, owner_sid, owner_len);
+		memcpy(&out->group, group_sid, group_len);
+	}
+	return total_len;
+}
+
+static int posix_info_extra_size(const void *beg, const void *end)
+{
+	int len = posix_info_parse(beg, end, NULL);
+
+	if (len < 0)
+		return -1;
+	return len - sizeof(struct smb2_posix_info);
+}
+
+static unsigned int
+num_entries(int infotype, char *bufstart, char *end_of_buf, char **lastentry,
+	    size_t size)
+{
+	int len;
+	unsigned int entrycount = 0;
+	unsigned int next_offset = 0;
+	char *entryptr;
+	FILE_DIRECTORY_INFO *dir_info;
+
+	if (bufstart == NULL)
+		return 0;
+
+	entryptr = bufstart;
+
+	while (1) {
+		if (entryptr + next_offset < entryptr ||
+		    entryptr + next_offset > end_of_buf ||
+		    entryptr + next_offset + size > end_of_buf) {
+			cifs_dbg(VFS, "malformed search entry would overflow\n");
+			break;
+		}
+
+		entryptr = entryptr + next_offset;
+		dir_info = (FILE_DIRECTORY_INFO *)entryptr;
+
+		if (infotype == SMB_FIND_FILE_POSIX_INFO)
+			len = posix_info_extra_size(entryptr, end_of_buf);
+		else
+			len = le32_to_cpu(dir_info->FileNameLength);
+
+		if (len < 0 ||
+		    entryptr + len < entryptr ||
+		    entryptr + len > end_of_buf ||
+		    entryptr + len + size > end_of_buf) {
+			cifs_dbg(VFS, "directory entry name would overflow frame end of buf %p\n",
+				 end_of_buf);
+			break;
+		}
+
+		*lastentry = entryptr;
+		entrycount++;
+
+		next_offset = le32_to_cpu(dir_info->NextEntryOffset);
+		if (!next_offset)
+			break;
+	}
+
+	return entrycount;
+}
+
+/*
+ * Readdir/FindFirst
+ */
+int SMB2_query_directory_init(const unsigned int xid,
+			      struct cifs_tcon *tcon,
+			      struct TCP_Server_Info *server,
+			      struct smb_rqst *rqst,
+			      u64 persistent_fid, u64 volatile_fid,
+			      int index, int info_level)
+{
+	struct smb2_query_directory_req *req;
+	unsigned char *bufptr;
+	__le16 asteriks = cpu_to_le16('*');
+	unsigned int output_size = CIFSMaxBufSize -
+		MAX_SMB2_CREATE_RESPONSE_SIZE -
+		MAX_SMB2_CLOSE_RESPONSE_SIZE;
+	unsigned int total_len;
+	struct kvec *iov = rqst->rq_iov;
+	int len, rc;
+
+	rc = smb2_plain_req_init(SMB2_QUERY_DIRECTORY, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	switch (info_level) {
+	case SMB_FIND_FILE_DIRECTORY_INFO:
+		req->FileInformationClass = FILE_DIRECTORY_INFORMATION;
+		break;
+	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
+		req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
+		break;
+	case SMB_FIND_FILE_POSIX_INFO:
+		req->FileInformationClass = SMB_FIND_FILE_POSIX_INFO;
+		break;
+	default:
+		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
+			info_level);
+		return -EINVAL;
+	}
+
+	req->FileIndex = cpu_to_le32(index);
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+
+	len = 0x2;
+	bufptr = req->Buffer;
+	memcpy(bufptr, &asteriks, len);
+
+	req->FileNameOffset =
+		cpu_to_le16(sizeof(struct smb2_query_directory_req));
+	req->FileNameLength = cpu_to_le16(len);
+	/*
+	 * BB could be 30 bytes or so longer if we used SMB2 specific
+	 * buffer lengths, but this is safe and close enough.
+	 */
+	output_size = min_t(unsigned int, output_size, server->maxBuf);
+	output_size = min_t(unsigned int, output_size, 2 << 15);
+	req->OutputBufferLength = cpu_to_le32(output_size);
+
+	iov[0].iov_base = (char *)req;
+	/* 1 for Buffer */
+	iov[0].iov_len = total_len - 1;
+
+	iov[1].iov_base = (char *)(req->Buffer);
+	iov[1].iov_len = len;
+
+	trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
+			tcon->ses->Suid, index, output_size);
+
+	return 0;
+}
+
+void SMB2_query_directory_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov) {
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+	}
+}
+
+int
+smb2_parse_query_directory(struct cifs_tcon *tcon,
+			   struct kvec *rsp_iov,
+			   int resp_buftype,
+			   struct cifs_search_info *srch_inf)
+{
+	struct smb2_query_directory_rsp *rsp;
+	size_t info_buf_size;
+	char *end_of_smb;
+	int rc;
+
+	rsp = (struct smb2_query_directory_rsp *)rsp_iov->iov_base;
+
+	switch (srch_inf->info_level) {
+	case SMB_FIND_FILE_DIRECTORY_INFO:
+		info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
+		break;
+	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
+		info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
+		break;
+	case SMB_FIND_FILE_POSIX_INFO:
+		/* note that posix payload are variable size */
+		info_buf_size = sizeof(struct smb2_posix_info);
+		break;
+	default:
+		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
+			 srch_inf->info_level);
+		return -EINVAL;
+	}
+
+	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
+			       le32_to_cpu(rsp->OutputBufferLength), rsp_iov,
+			       info_buf_size);
+	if (rc) {
+		cifs_tcon_dbg(VFS, "bad info payload");
+		return rc;
+	}
+
+	srch_inf->unicode = true;
+
+	if (srch_inf->ntwrk_buf_start) {
+		if (srch_inf->smallBuf)
+			cifs_small_buf_release(srch_inf->ntwrk_buf_start);
+		else
+			cifs_buf_release(srch_inf->ntwrk_buf_start);
+	}
+	srch_inf->ntwrk_buf_start = (char *)rsp;
+	srch_inf->srch_entries_start = srch_inf->last_entry =
+		(char *)rsp + le16_to_cpu(rsp->OutputBufferOffset);
+	end_of_smb = rsp_iov->iov_len + (char *)rsp;
+
+	srch_inf->entries_in_buffer = num_entries(
+		srch_inf->info_level,
+		srch_inf->srch_entries_start,
+		end_of_smb,
+		&srch_inf->last_entry,
+		info_buf_size);
+
+	srch_inf->index_of_last_entry += srch_inf->entries_in_buffer;
+	cifs_dbg(FYI, "num entries %d last_index %lld srch start %p srch end %p\n",
+		 srch_inf->entries_in_buffer, srch_inf->index_of_last_entry,
+		 srch_inf->srch_entries_start, srch_inf->last_entry);
+	if (resp_buftype == CIFS_LARGE_BUFFER)
+		srch_inf->smallBuf = false;
+	else if (resp_buftype == CIFS_SMALL_BUFFER)
+		srch_inf->smallBuf = true;
+	else
+		cifs_tcon_dbg(VFS, "Invalid search buffer type\n");
+
+	return 0;
+}
+
+int
+SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
+		     u64 persistent_fid, u64 volatile_fid, int index,
+		     struct cifs_search_info *srch_inf)
+{
+	struct smb_rqst rqst;
+	struct kvec iov[SMB2_QUERY_DIRECTORY_IOV_SIZE];
+	struct smb2_query_directory_rsp *rsp = NULL;
+	int resp_buftype = CIFS_NO_BUFFER;
+	struct kvec rsp_iov;
+	int rc = 0;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	int flags = 0;
+
+	if (!ses || !(ses->server))
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = SMB2_QUERY_DIRECTORY_IOV_SIZE;
+
+	rc = SMB2_query_directory_init(xid, tcon, server,
+				       &rqst, persistent_fid,
+				       volatile_fid, index,
+				       srch_inf->info_level);
+	if (rc)
+		goto qdir_exit;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	rsp = (struct smb2_query_directory_rsp *)rsp_iov.iov_base;
+
+	if (rc) {
+		if (rc == -ENODATA &&
+		    rsp->hdr.Status == STATUS_NO_MORE_FILES) {
+			trace_smb3_query_dir_done(xid, persistent_fid,
+				tcon->tid, tcon->ses->Suid, index, 0);
+			srch_inf->endOfSearch = true;
+			rc = 0;
+		} else {
+			trace_smb3_query_dir_err(xid, persistent_fid, tcon->tid,
+				tcon->ses->Suid, index, 0, rc);
+			cifs_stats_fail_inc(tcon, SMB2_QUERY_DIRECTORY_HE);
+		}
+		goto qdir_exit;
+	}
+
+	rc = smb2_parse_query_directory(tcon, &rsp_iov,	resp_buftype,
+					srch_inf);
+	if (rc) {
+		trace_smb3_query_dir_err(xid, persistent_fid, tcon->tid,
+			tcon->ses->Suid, index, 0, rc);
+		goto qdir_exit;
+	}
+	resp_buftype = CIFS_NO_BUFFER;
+
+	trace_smb3_query_dir_done(xid, persistent_fid, tcon->tid,
+			tcon->ses->Suid, index, srch_inf->entries_in_buffer);
+
+qdir_exit:
+	SMB2_query_directory_free(&rqst);
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
+int
+SMB2_set_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
+		   struct smb_rqst *rqst,
+		   u64 persistent_fid, u64 volatile_fid, u32 pid,
+		   u8 info_class, u8 info_type, u32 additional_info,
+		   void **data, unsigned int *size)
+{
+	struct smb2_set_info_req *req;
+	struct kvec *iov = rqst->rq_iov;
+	unsigned int i, total_len;
+	int rc;
+
+	rc = smb2_plain_req_init(SMB2_SET_INFO, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->hdr.Id.SyncId.ProcessId = cpu_to_le32(pid);
+	req->InfoType = info_type;
+	req->FileInfoClass = info_class;
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+	req->AdditionalInformation = cpu_to_le32(additional_info);
+
+	req->BufferOffset = cpu_to_le16(sizeof(struct smb2_set_info_req));
+	req->BufferLength = cpu_to_le32(*size);
+
+	memcpy(req->Buffer, *data, *size);
+	total_len += *size;
+
+	iov[0].iov_base = (char *)req;
+	/* 1 for Buffer */
+	iov[0].iov_len = total_len - 1;
+
+	for (i = 1; i < rqst->rq_nvec; i++) {
+		le32_add_cpu(&req->BufferLength, size[i]);
+		iov[i].iov_base = (char *)data[i];
+		iov[i].iov_len = size[i];
+	}
+
+	return 0;
+}
+
+void
+SMB2_set_info_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov)
+		cifs_buf_release(rqst->rq_iov[0].iov_base); /* request */
+}
+
+static int
+send_set_info(const unsigned int xid, struct cifs_tcon *tcon,
+	       u64 persistent_fid, u64 volatile_fid, u32 pid, u8 info_class,
+	       u8 info_type, u32 additional_info, unsigned int num,
+		void **data, unsigned int *size)
+{
+	struct smb_rqst rqst;
+	struct smb2_set_info_rsp *rsp = NULL;
+	struct kvec *iov;
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	int flags = 0;
+
+	if (!ses || !server)
+		return -EIO;
+
+	if (!num)
+		return -EINVAL;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	iov = kmalloc_array(num, sizeof(struct kvec), GFP_KERNEL);
+	if (!iov)
+		return -ENOMEM;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = num;
+
+	rc = SMB2_set_info_init(tcon, server,
+				&rqst, persistent_fid, volatile_fid, pid,
+				info_class, info_type, additional_info,
+				data, size);
+	if (rc) {
+		kfree(iov);
+		return rc;
+	}
+
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags,
+			    &rsp_iov);
+	SMB2_set_info_free(&rqst);
+	rsp = (struct smb2_set_info_rsp *)rsp_iov.iov_base;
+
+	if (rc != 0) {
+		cifs_stats_fail_inc(tcon, SMB2_SET_INFO_HE);
+		trace_smb3_set_info_err(xid, persistent_fid, tcon->tid,
+				ses->Suid, info_class, (__u32)info_type, rc);
+	}
+
+	free_rsp_buf(resp_buftype, rsp);
+	kfree(iov);
+	return rc;
+}
+
+int
+SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
+	     u64 volatile_fid, u32 pid, __le64 *eof)
+{
+	struct smb2_file_eof_info info;
+	void *data;
+	unsigned int size;
+
+	info.EndOfFile = *eof;
+
+	data = &info;
+	size = sizeof(struct smb2_file_eof_info);
+
+	trace_smb3_set_eof(xid, persistent_fid, tcon->tid, tcon->ses->Suid, le64_to_cpu(*eof));
+
+	return send_set_info(xid, tcon, persistent_fid, volatile_fid,
+			pid, FILE_END_OF_FILE_INFORMATION, SMB2_O_INFO_FILE,
+			0, 1, &data, &size);
+}
+
+int
+SMB2_set_acl(const unsigned int xid, struct cifs_tcon *tcon,
+		u64 persistent_fid, u64 volatile_fid,
+		struct cifs_ntsd *pnntsd, int pacllen, int aclflag)
+{
+	return send_set_info(xid, tcon, persistent_fid, volatile_fid,
+			current->tgid, 0, SMB2_O_INFO_SECURITY, aclflag,
+			1, (void **)&pnntsd, &pacllen);
+}
+
+int
+SMB2_set_ea(const unsigned int xid, struct cifs_tcon *tcon,
+	    u64 persistent_fid, u64 volatile_fid,
+	    struct smb2_file_full_ea_info *buf, int len)
+{
+	return send_set_info(xid, tcon, persistent_fid, volatile_fid,
+		current->tgid, FILE_FULL_EA_INFORMATION, SMB2_O_INFO_FILE,
+		0, 1, (void **)&buf, &len);
+}
+
+int
+SMB2_oplock_break(const unsigned int xid, struct cifs_tcon *tcon,
+		  const u64 persistent_fid, const u64 volatile_fid,
+		  __u8 oplock_level)
+{
+	struct smb_rqst rqst;
+	int rc;
+	struct smb2_oplock_break *req = NULL;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	int flags = CIFS_OBREAK_OP;
+	unsigned int total_len;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int resp_buf_type;
+
+	cifs_dbg(FYI, "SMB2_oplock_break\n");
+	rc = smb2_plain_req_init(SMB2_OPLOCK_BREAK, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	req->VolatileFid = volatile_fid;
+	req->PersistentFid = persistent_fid;
+	req->OplockLevel = oplock_level;
+	req->hdr.CreditRequest = cpu_to_le16(1);
+
+	flags |= CIFS_NO_RSP_BUF;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buf_type, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE);
+		cifs_dbg(FYI, "Send error in Oplock Break = %d\n", rc);
+	}
+
+	return rc;
+}
+
+void
+smb2_copy_fs_info_to_kstatfs(struct smb2_fs_full_size_info *pfs_inf,
+			     struct kstatfs *kst)
+{
+	kst->f_bsize = le32_to_cpu(pfs_inf->BytesPerSector) *
+			  le32_to_cpu(pfs_inf->SectorsPerAllocationUnit);
+	kst->f_blocks = le64_to_cpu(pfs_inf->TotalAllocationUnits);
+	kst->f_bfree  = kst->f_bavail =
+			le64_to_cpu(pfs_inf->CallerAvailableAllocationUnits);
+	return;
+}
+
+static void
+copy_posix_fs_info_to_kstatfs(FILE_SYSTEM_POSIX_INFO *response_data,
+			struct kstatfs *kst)
+{
+	kst->f_bsize = le32_to_cpu(response_data->BlockSize);
+	kst->f_blocks = le64_to_cpu(response_data->TotalBlocks);
+	kst->f_bfree =  le64_to_cpu(response_data->BlocksAvail);
+	if (response_data->UserBlocksAvail == cpu_to_le64(-1))
+		kst->f_bavail = kst->f_bfree;
+	else
+		kst->f_bavail = le64_to_cpu(response_data->UserBlocksAvail);
+	if (response_data->TotalFileNodes != cpu_to_le64(-1))
+		kst->f_files = le64_to_cpu(response_data->TotalFileNodes);
+	if (response_data->FreeFileNodes != cpu_to_le64(-1))
+		kst->f_ffree = le64_to_cpu(response_data->FreeFileNodes);
+
+	return;
+}
+
+static int
+build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon,
+		   struct TCP_Server_Info *server,
+		   int level, int outbuf_len, u64 persistent_fid,
+		   u64 volatile_fid)
+{
+	int rc;
+	struct smb2_query_info_req *req;
+	unsigned int total_len;
+
+	cifs_dbg(FYI, "Query FSInfo level %d\n", level);
+
+	if ((tcon->ses == NULL) || server == NULL)
+		return -EIO;
+
+	rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	req->InfoType = SMB2_O_INFO_FILESYSTEM;
+	req->FileInfoClass = level;
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+	/* 1 for pad */
+	req->InputBufferOffset =
+			cpu_to_le16(sizeof(struct smb2_query_info_req));
+	req->OutputBufferLength = cpu_to_le32(
+		outbuf_len + sizeof(struct smb2_query_info_rsp));
+
+	iov->iov_base = (char *)req;
+	iov->iov_len = total_len;
+	return 0;
+}
+
+static inline void free_qfs_info_req(struct kvec *iov)
+{
+	cifs_buf_release(iov->iov_base);
+}
+
+int
+SMB311_posix_qfs_info(const unsigned int xid, struct cifs_tcon *tcon,
+	      u64 persistent_fid, u64 volatile_fid, struct kstatfs *fsdata)
+{
+	struct smb_rqst rqst;
+	struct smb2_query_info_rsp *rsp = NULL;
+	struct kvec iov;
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	FILE_SYSTEM_POSIX_INFO *info = NULL;
+	int flags = 0;
+
+	rc = build_qfs_info_req(&iov, tcon, server,
+				FS_POSIX_INFORMATION,
+				sizeof(FILE_SYSTEM_POSIX_INFO),
+				persistent_fid, volatile_fid);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = &iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	free_qfs_info_req(&iov);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
+		goto posix_qfsinf_exit;
+	}
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+
+	info = (FILE_SYSTEM_POSIX_INFO *)(
+		le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
+	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
+			       le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
+			       sizeof(FILE_SYSTEM_POSIX_INFO));
+	if (!rc)
+		copy_posix_fs_info_to_kstatfs(info, fsdata);
+
+posix_qfsinf_exit:
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+
+int
+SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
+	      u64 persistent_fid, u64 volatile_fid, struct kstatfs *fsdata)
+{
+	struct smb_rqst rqst;
+	struct smb2_query_info_rsp *rsp = NULL;
+	struct kvec iov;
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	struct smb2_fs_full_size_info *info = NULL;
+	int flags = 0;
+
+	rc = build_qfs_info_req(&iov, tcon, server,
+				FS_FULL_SIZE_INFORMATION,
+				sizeof(struct smb2_fs_full_size_info),
+				persistent_fid, volatile_fid);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = &iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	free_qfs_info_req(&iov);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
+		goto qfsinf_exit;
+	}
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+
+	info = (struct smb2_fs_full_size_info *)(
+		le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
+	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
+			       le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
+			       sizeof(struct smb2_fs_full_size_info));
+	if (!rc)
+		smb2_copy_fs_info_to_kstatfs(info, fsdata);
+
+qfsinf_exit:
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+
+int
+SMB2_QFS_attr(const unsigned int xid, struct cifs_tcon *tcon,
+	      u64 persistent_fid, u64 volatile_fid, int level)
+{
+	struct smb_rqst rqst;
+	struct smb2_query_info_rsp *rsp = NULL;
+	struct kvec iov;
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype, max_len, min_len;
+	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *server = cifs_pick_channel(ses);
+	unsigned int rsp_len, offset;
+	int flags = 0;
+
+	if (level == FS_DEVICE_INFORMATION) {
+		max_len = sizeof(FILE_SYSTEM_DEVICE_INFO);
+		min_len = sizeof(FILE_SYSTEM_DEVICE_INFO);
+	} else if (level == FS_ATTRIBUTE_INFORMATION) {
+		max_len = sizeof(FILE_SYSTEM_ATTRIBUTE_INFO);
+		min_len = MIN_FS_ATTR_INFO_SIZE;
+	} else if (level == FS_SECTOR_SIZE_INFORMATION) {
+		max_len = sizeof(struct smb3_fs_ss_info);
+		min_len = sizeof(struct smb3_fs_ss_info);
+	} else if (level == FS_VOLUME_INFORMATION) {
+		max_len = sizeof(struct smb3_fs_vol_info) + MAX_VOL_LABEL_LEN;
+		min_len = sizeof(struct smb3_fs_vol_info);
+	} else {
+		cifs_dbg(FYI, "Invalid qfsinfo level %d\n", level);
+		return -EINVAL;
+	}
+
+	rc = build_qfs_info_req(&iov, tcon, server,
+				level, max_len,
+				persistent_fid, volatile_fid);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = &iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buftype, flags, &rsp_iov);
+	free_qfs_info_req(&iov);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
+		goto qfsattr_exit;
+	}
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+
+	rsp_len = le32_to_cpu(rsp->OutputBufferLength);
+	offset = le16_to_cpu(rsp->OutputBufferOffset);
+	rc = smb2_validate_iov(offset, rsp_len, &rsp_iov, min_len);
+	if (rc)
+		goto qfsattr_exit;
+
+	if (level == FS_ATTRIBUTE_INFORMATION)
+		memcpy(&tcon->fsAttrInfo, offset
+			+ (char *)rsp, min_t(unsigned int,
+			rsp_len, max_len));
+	else if (level == FS_DEVICE_INFORMATION)
+		memcpy(&tcon->fsDevInfo, offset
+			+ (char *)rsp, sizeof(FILE_SYSTEM_DEVICE_INFO));
+	else if (level == FS_SECTOR_SIZE_INFORMATION) {
+		struct smb3_fs_ss_info *ss_info = (struct smb3_fs_ss_info *)
+			(offset + (char *)rsp);
+		tcon->ss_flags = le32_to_cpu(ss_info->Flags);
+		tcon->perf_sector_size =
+			le32_to_cpu(ss_info->PhysicalBytesPerSectorForPerf);
+	} else if (level == FS_VOLUME_INFORMATION) {
+		struct smb3_fs_vol_info *vol_info = (struct smb3_fs_vol_info *)
+			(offset + (char *)rsp);
+		tcon->vol_serial_number = vol_info->VolumeSerialNumber;
+		tcon->vol_create_time = vol_info->VolumeCreationTime;
+	}
+
+qfsattr_exit:
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+
+int
+smb2_lockv(const unsigned int xid, struct cifs_tcon *tcon,
+	   const __u64 persist_fid, const __u64 volatile_fid, const __u32 pid,
+	   const __u32 num_lock, struct smb2_lock_element *buf)
+{
+	struct smb_rqst rqst;
+	int rc = 0;
+	struct smb2_lock_req *req = NULL;
+	struct kvec iov[2];
+	struct kvec rsp_iov;
+	int resp_buf_type;
+	unsigned int count;
+	int flags = CIFS_NO_RSP_BUF;
+	unsigned int total_len;
+	struct TCP_Server_Info *server = cifs_pick_channel(tcon->ses);
+
+	cifs_dbg(FYI, "smb2_lockv num lock %d\n", num_lock);
+
+	rc = smb2_plain_req_init(SMB2_LOCK, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	req->hdr.Id.SyncId.ProcessId = cpu_to_le32(pid);
+	req->LockCount = cpu_to_le16(num_lock);
+
+	req->PersistentFileId = persist_fid;
+	req->VolatileFileId = volatile_fid;
+
+	count = num_lock * sizeof(struct smb2_lock_element);
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len - sizeof(struct smb2_lock_element);
+	iov[1].iov_base = (char *)buf;
+	iov[1].iov_len = count;
+
+	cifs_stats_inc(&tcon->stats.cifs_stats.num_locks);
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 2;
+
+	rc = cifs_send_recv(xid, tcon->ses, server,
+			    &rqst, &resp_buf_type, flags,
+			    &rsp_iov);
+	cifs_small_buf_release(req);
+	if (rc) {
+		cifs_dbg(FYI, "Send error in smb2_lockv = %d\n", rc);
+		cifs_stats_fail_inc(tcon, SMB2_LOCK_HE);
+		trace_smb3_lock_err(xid, persist_fid, tcon->tid,
+				    tcon->ses->Suid, rc);
+	}
+
+	return rc;
+}
+
+int
+SMB2_lock(const unsigned int xid, struct cifs_tcon *tcon,
+	  const __u64 persist_fid, const __u64 volatile_fid, const __u32 pid,
+	  const __u64 length, const __u64 offset, const __u32 lock_flags,
+	  const bool wait)
+{
+	struct smb2_lock_element lock;
+
+	lock.Offset = cpu_to_le64(offset);
+	lock.Length = cpu_to_le64(length);
+	lock.Flags = cpu_to_le32(lock_flags);
+	if (!wait && lock_flags != SMB2_LOCKFLAG_UNLOCK)
+		lock.Flags |= cpu_to_le32(SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
+
+	return smb2_lockv(xid, tcon, persist_fid, volatile_fid, pid, 1, &lock);
+}
+
+int
+SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon,
+		 __u8 *lease_key, const __le32 lease_state)
+{
+	struct smb_rqst rqst;
+	int rc;
+	struct smb2_lease_ack *req = NULL;
+	struct cifs_ses *ses = tcon->ses;
+	int flags = CIFS_OBREAK_OP;
+	unsigned int total_len;
+	struct kvec iov[1];
+	struct kvec rsp_iov;
+	int resp_buf_type;
+	__u64 *please_key_high;
+	__u64 *please_key_low;
+	struct TCP_Server_Info *server = cifs_pick_channel(tcon->ses);
+
+	cifs_dbg(FYI, "SMB2_lease_break\n");
+	rc = smb2_plain_req_init(SMB2_OPLOCK_BREAK, tcon, server,
+				 (void **) &req, &total_len);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	req->hdr.CreditRequest = cpu_to_le16(1);
+	req->StructureSize = cpu_to_le16(36);
+	total_len += 12;
+
+	memcpy(req->LeaseKey, lease_key, 16);
+	req->LeaseState = lease_state;
+
+	flags |= CIFS_NO_RSP_BUF;
+
+	iov[0].iov_base = (char *)req;
+	iov[0].iov_len = total_len;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, server,
+			    &rqst, &resp_buf_type, flags, &rsp_iov);
+	cifs_small_buf_release(req);
+
+	please_key_low = (__u64 *)lease_key;
+	please_key_high = (__u64 *)(lease_key+8);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_OPLOCK_BREAK_HE);
+		trace_smb3_lease_err(le32_to_cpu(lease_state), tcon->tid,
+			ses->Suid, *please_key_low, *please_key_high, rc);
+		cifs_dbg(FYI, "Send error in Lease Break = %d\n", rc);
+	} else
+		trace_smb3_lease_done(le32_to_cpu(lease_state), tcon->tid,
+			ses->Suid, *please_key_low, *please_key_high);
+
+	return rc;
+}