text: /*
   *   fs/cifs/smb2pdu.c
   *
   *   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
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Lesser General Public License as published
   *   by the Free Software Foundation; either version 2.1 of the License, or
   *   (at your option) any later version.
   *
   *   This library is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU Lesser General Public License for more details.
   *
   *   You should have received a copy of the GNU Lesser General Public License
   *   along with this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
   /* 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 "smb2pdu.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
  
  /*
   *  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_sync_hdr *shdr, __le16 smb2_cmd,
  		  const struct cifs_tcon *tcon,
  		  struct TCP_Server_Info *server)
  {
  	shdr->ProtocolId = SMB2_PROTO_NUMBER;
  	shdr->StructureSize = cpu_to_le16(64);
  	shdr->Command = smb2_cmd;
  	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->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->TreeId = tcon->tid;
  	/* Uid is not converted */
  	if (tcon->ses)
  		shdr->SessionId = 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;
  	struct nls_table *nls_codepage;
  	struct cifs_ses *ses;
  	int retries;
  
  	/*
  	 * 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;
  
  	if (smb2_command == SMB2_TREE_CONNECT)
  		return 0;
  
  	if (tcon->tidStatus == CifsExiting) {
  		/*
  		 * only tree disconnect, open, and write,
  		 * (and ulogoff which does not have tcon)
  		 * are allowed as we start force umount.
  		 */
  		if ((smb2_command != SMB2_WRITE) &&
  		   (smb2_command != SMB2_CREATE) &&
  		   (smb2_command != SMB2_TREE_DISCONNECT)) {
  			cifs_dbg(FYI, "can not send cmd %d while umounting\n",
  				 smb2_command);
  			return -ENODEV;
  		}
  	}
  	if ((!tcon->ses) || (tcon->ses->status == CifsExiting) ||
  	    (!tcon->ses->server) || !server)
  		return -EIO;
  
  	ses = tcon->ses;
  	retries = server->nr_targets;
  
  	/*
  	 * Give demultiplex thread up to 10 seconds to each target available for
  	 * reconnect -- should be greater than cifs socket timeout which is 7
  	 * seconds.
  	 */
  	while (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:
  			return -EAGAIN;
  		}
  
  		rc = wait_event_interruptible_timeout(server->response_q,
  						      (server->tcpStatus != CifsNeedReconnect),
  						      10 * HZ);
  		if (rc < 0) {
  			cifs_dbg(FYI, "%s: aborting reconnect due to a received signal by the process\n",
  				 __func__);
  			return -ERESTARTSYS;
  		}
  
  		/* are we still trying to reconnect? */
  		if (server->tcpStatus != CifsNeedReconnect)
  			break;
  
  		if (retries && --retries)
  			continue;
  
  		/*
  		 * on "soft" mounts we wait once. Hard mounts keep
  		 * retrying until process is killed or server comes
  		 * back on-line
  		 */
  		if (!tcon->retry) {
  			cifs_dbg(FYI, "gave up waiting on reconnect in smb_init\n");
  			return -EHOSTDOWN;
  		}
  		retries = server->nr_targets;
  	}
  
  	if (!tcon->ses->need_reconnect && !tcon->need_reconnect)
  		return 0;
  
  	nls_codepage = load_nls_default();
  
  	/*
  	 * need to prevent multiple threads trying to simultaneously reconnect
  	 * the same SMB session
  	 */
  	mutex_lock(&tcon->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.
  	 */
  	if (server->tcpStatus == CifsNeedReconnect) {
  		rc = -EHOSTDOWN;
  		mutex_unlock(&tcon->ses->session_mutex);
  		goto out;
  	}
  
  	/*
  	 * If we are reconnecting an extra channel, bind
  	 */
  	if (server->is_channel) {
  		ses->binding = true;
  		ses->binding_chan = cifs_ses_find_chan(ses, server);
  	}
  
  	rc = cifs_negotiate_protocol(0, tcon->ses);
  	if (!rc && tcon->ses->need_reconnect) {
  		rc = cifs_setup_session(0, tcon->ses, nls_codepage);
  		if ((rc == -EACCES) && !tcon->retry) {
  			rc = -EHOSTDOWN;
  			ses->binding = false;
  			ses->binding_chan = NULL;
  			mutex_unlock(&tcon->ses->session_mutex);
  			goto failed;
  		}
  	}
  	/*
  	 * End of channel binding
  	 */
  	ses->binding = false;
  	ses->binding_chan = NULL;
  
  	if (rc || !tcon->need_reconnect) {
  		mutex_unlock(&tcon->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(&tcon->ses->session_mutex);
  
  	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
  	if (rc) {
  		/* If sess reconnected but tcon didn't, something strange ... */
  		pr_warn_once("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_sync_pdu *spdu = (struct smb2_sync_pdu *)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->sync_hdr, smb2_command, tcon, server);
  	spdu->StructureSize2 = cpu_to_le16(parmsize);
  
  	*total_len = parmsize + sizeof(struct smb2_sync_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 */
  	if (smb2_command == SMB2_SET_INFO)
  		*request_buf = cifs_buf_get();
  	else
  		*request_buf = cifs_small_buf_get();
  	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_sync_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_LINUX_CLIENT_SALT_SIZE);
  	get_random_bytes(pneg_ctxt->Salt, SMB311_LINUX_CLIENT_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 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 DIV_ROUND_UP(le16_to_cpu(pneg_ctxt->DataLength) +
  			sizeof(struct smb2_neg_context), 8) * 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)
  {
  	char *pneg_ctxt;
  	unsigned int ctxt_len;
  
  	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 = roundup(*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 = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
  	*total_len += ctxt_len;
  	pneg_ctxt += ctxt_len;
  
  	build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt);
  	ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_encryption_neg_context), 8) * 8;
  	*total_len += ctxt_len;
  	pneg_ctxt += ctxt_len;
  
  	if (server->compress_algorithm) {
  		build_compression_ctxt((struct smb2_compression_capabilities_context *)
  				pneg_ctxt);
  		ctxt_len = DIV_ROUND_UP(
  			sizeof(struct smb2_compression_capabilities_context),
  				8) * 8;
  		*total_len += ctxt_len;
  		pneg_ctxt += ctxt_len;
  		req->NegotiateContextCount = cpu_to_le16(5);
  	} else
  		req->NegotiateContextCount = cpu_to_le16(4);
  
  	ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
  					server->hostname);
  	*total_len += ctxt_len;
  	pneg_ctxt += ctxt_len;
  
  	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
  	*total_len += sizeof(struct smb2_posix_neg_context);
  }
  
  static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
  {
  	unsigned int len = le16_to_cpu(ctxt->DataLength);
  
  	/* If invalid preauth context warn but use what we requested, SHA-512 */
  	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);
  
  	/* sizeof compress context is a one element compression capbility struct */
  	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);
  	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 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 == 0)
  			break;
  
  		if (len_of_ctxts < sizeof(struct smb2_neg_context))
  			break;
  
  		pctx = (struct smb2_neg_context *)(offset + (char *)rsp);
  		clen = le16_to_cpu(pctx->DataLength);
  		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
  			cifs_server_dbg(VFS, "unknown negcontext of type %d ignored\n",
  				le16_to_cpu(pctx->ContextType));
  
  		if (rc)
  			break;
  		/* offsets must be 8 byte aligned */
  		clen = (clen + 7) & ~0x7;
  		offset += clen + sizeof(struct smb2_neg_context);
  		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 smb_rqst rqst;
  	struct smb2_negotiate_req *req;
  	struct smb2_negotiate_rsp *rsp;
  	struct kvec iov[1];
  	struct kvec rsp_iov;
  	int rc = 0;
  	int resp_buftype;
  	struct TCP_Server_Info *server = cifs_ses_server(ses);
  	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->sync_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->DialectCount = cpu_to_le16(2);
  		total_len += 4;
  	} 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);
  
  	/* 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,
  		     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;
  
  	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");
  			return -EIO;
  		} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
  			cifs_server_dbg(VFS,
  				"SMB2.1 dialect returned but not requested\n");
  			return -EIO;
  		}
  	} 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");
  			return -EIO;
  		} 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));
  		return -EIO;
  	}
  
  	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));
  		rc = -EIO;
  		goto neg_exit;
  	}
  	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;
  
  	security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
  					       (struct smb2_sync_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);
  	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->DialectCount = cpu_to_le16(2);
  		/* structure is big enough for 3 dialects, sending only 2 */
  		inbuflen = sizeof(*pneg_inbuf) -
  				(2 * 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 3 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 3 dialects, sending only 1 */
  		inbuflen = sizeof(*pneg_inbuf) -
  				sizeof(pneg_inbuf->Dialects[0]) * 2;
  	}
  
  	rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
  		FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
  		(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 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 smb2_sess_setup_req *req;
  	struct TCP_Server_Info *server = cifs_ses_server(ses);
  	unsigned int total_len;
  
  	rc = smb2_plain_req_init(SMB2_SESSION_SETUP, NULL, server,
  				 (void **) &req,
  				 &total_len);
  	if (rc)
  		return rc;
  
  	if (sess_data->ses->binding) {
  		req->sync_hdr.SessionId = sess_data->ses->Suid;
  		req->sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
  		req->PreviousSessionId = 0;
  		req->Flags = SMB2_SESSION_REQ_FLAG_BINDING;
  	} else {
  		/* First session, not a reauthenticate */
  		req->sync_hdr.SessionId = 0;
  		/*
  		 * if reconnect, we need to send previous sess id
  		 * otherwise it is 0
  		 */
  		req->PreviousSessionId = sess_data->previous_session;
  		req->Flags = 0; /* MBZ */
  	}
  
  	/* enough to enable echos and oplocks and one max size write */
  	req->sync_hdr.CreditRequest = cpu_to_le16(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)
  {
  	free_rsp_buf(sess_data->buf0_type, sess_data->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) - 1 /* pad */);
  	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,
  			    cifs_ses_server(sess_data->ses),
  			    &rqst,
  			    &sess_data->buf0_type,
  			    CIFS_LOG_ERROR | CIFS_NEG_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 = cifs_ses_server(ses);
  
  	mutex_lock(&server->srv_mutex);
  	if (server->ops->generate_signingkey) {
  		rc = server->ops->generate_signingkey(ses);
  		if (rc) {
  			cifs_dbg(FYI,
  				"SMB3 session key generation failed\n");
  			mutex_unlock(&server->srv_mutex);
  			return rc;
  		}
  	}
  	if (!server->session_estab) {
  		server->sequence_number = 0x2;
  		server->session_estab = true;
  	}
  	mutex_unlock(&server->srv_mutex);
  
  	cifs_dbg(FYI, "SMB2/3 session established successfully\n");
  	/* keep existing ses state if binding */
  	if (!ses->binding) {
  		spin_lock(&GlobalMid_Lock);
  		ses->status = CifsGood;
  		ses->need_reconnect = false;
  		spin_unlock(&GlobalMid_Lock);
  	}
  
  	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 cifs_spnego_msg *msg;
  	struct key *spnego_key = NULL;
  	struct smb2_sess_setup_rsp *rsp = NULL;
  
  	rc = SMB2_sess_alloc_buffer(sess_data);
  	if (rc)
  		goto out;
  
  	spnego_key = cifs_get_spnego_key(ses);
  	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;
  	}
  
  	/* keep session key if binding */
  	if (!ses->binding) {
  		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 (!ses->binding) {
  		ses->Suid = rsp->sync_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);
  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 smb2_sess_setup_rsp *rsp = NULL;
  	char *ntlmssp_blob = NULL;
  	bool use_spnego = false; /* else use raw ntlmssp */
  	u16 blob_length = 0;
  
  	/*
  	 * 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;
  
  	ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE),
  			       GFP_KERNEL);
  	if (ntlmssp_blob == NULL) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	build_ntlmssp_negotiate_blob(ntlmssp_blob, ses);
  	if (use_spnego) {
  		/* BB eventually need to add this */
  		cifs_dbg(VFS, "spnego not supported for SMB2 yet\n");
  		rc = -EOPNOTSUPP;
  		goto out;
  	} else {
  		blob_length = sizeof(struct _NEGOTIATE_MESSAGE);
  		/* with raw NTLMSSP we don't encapsulate in SPNEGO */
  	}
  	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->sync_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");
  
  	/* keep existing ses id and flags if binding */
  	if (!ses->binding) {
  		ses->Suid = rsp->sync_hdr.SessionId;
  		ses->session_flags = le16_to_cpu(rsp->SessionFlags);
  	}
  
  out:
  	kfree(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(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 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;
  
  	rc = SMB2_sess_alloc_buffer(sess_data);
  	if (rc)
  		goto out;
  
  	req = (struct smb2_sess_setup_req *) sess_data->iov[0].iov_base;
  	req->sync_hdr.SessionId = ses->Suid;
  
  	rc = build_ntlmssp_auth_blob(&ntlmssp_blob, &blob_length, ses,
  					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;
  
  	/* keep existing ses id and flags if binding */
  	if (!ses->binding) {
  		ses->Suid = rsp->sync_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(ntlmssp_blob);
  	SMB2_sess_free_buffer(sess_data);
  	kfree(ses->ntlmssp);
  	ses->ntlmssp = NULL;
  	sess_data->result = rc;
  	sess_data->func = NULL;
  }
  
  static int
  SMB2_select_sec(struct cifs_ses *ses, struct SMB2_sess_data *sess_data)
  {
  	int type;
  
  	type = smb2_select_sectype(cifs_ses_server(ses), 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,
  		const struct nls_table *nls_cp)
  {
  	int rc = 0;
  	struct TCP_Server_Info *server = cifs_ses_server(ses);
  	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;
  
  	rc = SMB2_select_sec(ses, sess_data);
  	if (rc)
  		goto out;
  	sess_data->xid = xid;
  	sess_data->ses = ses;
  	sess_data->buf0_type = CIFS_NO_BUFFER;
  	sess_data->nls_cp = (struct nls_table *) nls_cp;
  	sess_data->previous_session = ses->Suid;
  
  	/*
  	 * 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(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 */
  	if (ses->need_reconnect)
  		goto smb2_session_already_dead;
  
  	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->sync_hdr.SessionId = ses->Suid;
  
  	if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA)
  		flags |= CIFS_TRANSFORM_REQ;
  	else if (server->sign)
  		req->sync_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)
  			- 1 /* pad */);
  	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->sync_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 */
  	req->sync_hdr.CreditRequest = cpu_to_le16(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) {
  		if (tcon) {
  			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->tidStatus = CifsGood;
  	tcon->need_reconnect = false;
  	tcon->tid = rsp->sync_hdr.TreeId;
  	strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
  
  	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->sync_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;
  
  	if ((tcon->need_reconnect) || (tcon->ses->need_reconnect))
  		return 0;
  
  	close_shroot_lease(&tcon->crfid);
  
  	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);
  
  	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 = roundup(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 cifs_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);
  	memcpy(aclptr, &acl, sizeof(struct cifs_acl));
  
  	buf->ccontext.DataLength = cpu_to_le32(ptr - (__u8 *)&buf->sd);
  	*len = ptr - (__u8 *)buf;
  
  	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 between the treename and
  	 * path
  	 */
  	*out_len = treename_len + 1 + path_len;
  
  	/*
  	 * final path needs to be null-terminated UTF16 with a
  	 * size aligned to 8
  	 */
  
  	*out_size = roundup((*out_len+1)*2, 8);
  	*out_path = kzalloc(*out_size, GFP_KERNEL);
  	if (!*out_path)
  		return -ENOMEM;
  
  	cp = load_nls_default();
  	cifs_strtoUTF16(*out_path, treename, treename_len, cp);
  	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->sync_hdr.Flags |= SMB2_FLAGS_DFS_OPERATIONS;
  		rc = alloc_path_with_tree_prefix(&copy_path, &copy_size,
  						 &name_len,
  						 tcon->treeName, 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, 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;
  	}
  
  	rsp = (struct smb2_create_rsp *)rsp_iov.iov_base;
  	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->sync_hdr.Flags |= SMB2_FLAGS_DFS_OPERATIONS;
  		rc = alloc_path_with_tree_prefix(&copy_path, &copy_size,
  						 &name_len,
  						 tcon->treeName, 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 = uni_path_len;
  		if (copy_size % 8 != 0)
  			copy_size = roundup(copy_size, 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->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->treeName);
  			tcon->need_reconnect = true;
  		}
  		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->sync_hdr.MessageId);
  #endif /* CIFS_DEBUG2 */
  
  	if (buf) {
  		memcpy(buf, &rsp->CreationTime, 32);
  		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,
  		bool is_fsctl, 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->sync_hdr.CreditCharge =
  		cpu_to_le16(DIV_ROUND_UP(max(indatalen, max_response_size),
  					 SMB2_MAX_BUFFER_SIZE));
  	if (is_fsctl)
  		req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);
  	else
  		req->Flags = 0;
  
  	/* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */
  	if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO)
  		req->sync_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, bool is_fsctl,
  	   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,
  			     is_fsctl, 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;
  
  	*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, true /* is_fsctl */,
  			(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);
  		/*
  		 * Note that have to subtract 4 since struct network_open_info
  		 * has a final 4 byte pad that close response does not have
  		 */
  		if (pbuf)
  			memcpy(pbuf, (char *)&rsp->CreationTime, sizeof(*pbuf) - 4);
  	}
  
  	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, buffer_length);
  
  	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;
  	int rc;
  
  	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 = total_len - 1 + input_len;
  	return 0;
  }
  
  void
  SMB2_query_info_free(struct smb_rqst *rqst)
  {
  	if (rqst && rqst->rq_iov)
  		cifs_small_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, 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);
  }
  
  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);
  }
  
  int
  SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
  		u64 persistent_fid, u64 volatile_fid,
  		void **data, u32 *plen)
  {
  	__u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
  	*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)
  {
  	struct cifs_ses *ses = tcon->ses;
  	struct TCP_Server_Info *server = cifs_pick_channel(ses);
  	struct smb_rqst rqst;
  	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));
  	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);
  
   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->sync_hdr.CreditRequest);
  		credits.instance = server->reconnect_instance;
  	}
  
  	DeleteMidQEntry(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 cifs_ses *ses;
  	struct cifs_tcon *tcon, *tcon2;
  	struct list_head tmp_list;
  	int tcon_exist = false;
  	int rc;
  	int resched = false;
  
  
  	/* Prevent simultaneous reconnects that can corrupt tcon->rlist list */
  	mutex_lock(&server->reconnect_mutex);
  
  	INIT_LIST_HEAD(&tmp_list);
  	cifs_dbg(FYI, "Need negotiate, reconnecting tcons\n");
  
  	spin_lock(&cifs_tcp_ses_lock);
  	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
  		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_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_exist = true;
  			ses->ses_count++;
  		}
  	}
  	/*
  	 * 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)
  		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);
  	}
  
  	cifs_dbg(FYI, "Reconnecting tcons finished\n");
  	if (resched)
  		queue_delayed_work(cifsiod_wq, &server->reconnect, 2 * HZ);
  	mutex_unlock(&server->reconnect_mutex);
  
  	/* now we can safely release srv struct */
  	if (tcon_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\n");
  
  	if (server->tcpStatus == CifsNeedNegotiate) {
  		/* No need to send echo on newly established connections */
  		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
  		return rc;
  	}
  
  	rc = smb2_plain_req_init(SMB2_ECHO, NULL, server,
  				 (void **)&req, &total_len);
  	if (rc)
  		return rc;
  
  	req->sync_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;
  }
  
  /*
   * 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_plain_req *req = NULL;
  	struct smb2_sync_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->sync_hdr;
  	shdr->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 (server->rdma && rdata && !server->sign &&
  		rdata->bytes >= server->smbd_conn->rdma_readwrite_threshold) {
  
  		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_plain_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 = DIV_ROUND_UP(*total_len, 8) * 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 = 0xFFFFFFFF;
  			shdr->TreeId = 0xFFFFFFFF;
  			req->PersistentFileId = 0xFFFFFFFF;
  			req->VolatileFileId = 0xFFFFFFFF;
  		}
  	}
  	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_sync_hdr *shdr =
  				(struct smb2_sync_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,
  				 .rq_pages = rdata->pages,
  				 .rq_offset = rdata->page_offset,
  				 .rq_npages = rdata->nr_pages,
  				 .rq_pagesz = rdata->pagesz,
  				 .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);
  	DeleteMidQEntry(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_sync_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;
  
  	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_sync_hdr *)buf;
  
  	if (rdata->credits.value > 0) {
  		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
  						SMB2_MAX_BUFFER_SIZE));
  		shdr->CreditRequest = cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 8);
  
  		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_plain_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->sync_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->sync_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->treeName);
  	} 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);
  	DeleteMidQEntry(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_sync_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;
  
  	if (!wdata->server)
  		server = wdata->server = cifs_pick_channel(tcon->ses);
  
  	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_sync_hdr *)req;
  	shdr->ProcessId = cpu_to_le32(wdata->cfile->pid);
  
  	req->PersistentFileId = wdata->cfile->fid.persistent_fid;
  	req->VolatileFileId = wdata->cfile->fid.volatile_fid;
  	req->WriteChannelInfoOffset = 0;
  	req->WriteChannelInfoLength = 0;
  	req->Channel = 0;
  	req->Offset = cpu_to_le64(wdata->offset);
  	req->DataOffset = cpu_to_le16(
  				offsetof(struct smb2_write_req, Buffer));
  	req->RemainingBytes = 0;
  
  	trace_smb3_write_enter(0 /* xid */, wdata->cfile->fid.persistent_fid,
  		tcon->tid, tcon->ses->Suid, wdata->offset, wdata->bytes);
  #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 (server->rdma && !server->sign && wdata->bytes >=
  		server->smbd_conn->rdma_readwrite_threshold) {
  
  		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",
  		 wdata->offset, wdata->bytes);
  
  #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(wdata->bytes);
  #else
  	req->Length = cpu_to_le32(wdata->bytes);
  #endif
  
  	if (wdata->credits.value > 0) {
  		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
  						    SMB2_MAX_BUFFER_SIZE));
  		shdr->CreditRequest = cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 8);
  
  		rc = adjust_credits(server, &wdata->credits, wdata->bytes);
  		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 */, req->PersistentFileId,
  				     tcon->tid, tcon->ses->Suid, wdata->offset,
  				     wdata->bytes, 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->sync_hdr.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 sid_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;
  	sid_len = posix_info_sid_size(owner_sid, end);
  	if (sid_len < 0)
  		return -1;
  	total_len += sid_len;
  
  	/* check group sid */
  	group_sid = beg + total_len;
  	sid_len = posix_info_sid_size(group_sid, end);
  	if (sid_len < 0)
  		return -1;
  	total_len += sid_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,
  		       posix_info_sid_size(owner_sid, end));
  		memcpy(&out->group, group_sid,
  		       posix_info_sid_size(group_sid, end));
  	}
  	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) - 1);
  	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->sync_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->sync_hdr.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) - 1);
  	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);
  
  	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->sync_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) - 1);
  	req->OutputBufferLength = cpu_to_le32(
  		outbuf_len + sizeof(struct smb2_query_info_rsp) - 1);
  
  	iov->iov_base = (char *)req;
  	iov->iov_len = total_len;
  	return 0;
  }
  
  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);
  	cifs_small_buf_release(iov.iov_base);
  	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);
  	cifs_small_buf_release(iov.iov_base);
  	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);
  	cifs_small_buf_release(iov.iov_base);
  	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->sync_hdr.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->sync_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;
  }
  