fs/cifs/connect.c

/*
 *   fs/cifs/connect.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2011
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   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
 */
#include <linux/fs.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/sched/signal.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/pagevec.h>
#include <linux/freezer.h>
#include <linux/namei.h>
#include <linux/uuid.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <linux/inet.h>
#include <linux/module.h>
#include <keys/user-type.h>
#include <net/ipv6.h>
#include <linux/parser.h>
#include <linux/bvec.h>

#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
#include "fscache.h"
#ifdef CONFIG_CIFS_SMB2
#include "smb2proto.h"
#endif

#define CIFS_PORT 445
#define RFC1001_PORT 139

extern mempool_t *cifs_req_poolp;

/* FIXME: should these be tunable? */
#define TLINK_ERROR_EXPIRE	(1 * HZ)
#define TLINK_IDLE_EXPIRE	(600 * HZ)

enum {
	/* Mount options that take no arguments */
	Opt_user_xattr, Opt_nouser_xattr,
	Opt_forceuid, Opt_noforceuid,
	Opt_forcegid, Opt_noforcegid,
	Opt_noblocksend, Opt_noautotune,
	Opt_hard, Opt_soft, Opt_perm, Opt_noperm,
	Opt_mapposix, Opt_nomapposix,
	Opt_mapchars, Opt_nomapchars, Opt_sfu,
	Opt_nosfu, Opt_nodfs, Opt_posixpaths,
	Opt_noposixpaths, Opt_nounix,
	Opt_nocase,
	Opt_brl, Opt_nobrl,
	Opt_forcemandatorylock, Opt_setuidfromacl, Opt_setuids,
	Opt_nosetuids, Opt_dynperm, Opt_nodynperm,
	Opt_nohard, Opt_nosoft,
	Opt_nointr, Opt_intr,
	Opt_nostrictsync, Opt_strictsync,
	Opt_serverino, Opt_noserverino,
	Opt_rwpidforward, Opt_cifsacl, Opt_nocifsacl,
	Opt_acl, Opt_noacl, Opt_locallease,
	Opt_sign, Opt_seal, Opt_noac,
	Opt_fsc, Opt_mfsymlinks,
	Opt_multiuser, Opt_sloppy, Opt_nosharesock,
	Opt_persistent, Opt_nopersistent,
	Opt_resilient, Opt_noresilient,
	Opt_domainauto,

	/* Mount options which take numeric value */
	Opt_backupuid, Opt_backupgid, Opt_uid,
	Opt_cruid, Opt_gid, Opt_file_mode,
	Opt_dirmode, Opt_port,
	Opt_rsize, Opt_wsize, Opt_actimeo,
	Opt_echo_interval, Opt_max_credits,
	Opt_snapshot,

	/* Mount options which take string value */
	Opt_user, Opt_pass, Opt_ip,
	Opt_domain, Opt_srcaddr, Opt_iocharset,
	Opt_netbiosname, Opt_servern,
	Opt_ver, Opt_vers, Opt_sec, Opt_cache,

	/* Mount options to be ignored */
	Opt_ignore,

	/* Options which could be blank */
	Opt_blank_pass,
	Opt_blank_user,
	Opt_blank_ip,

	Opt_err
};

static const match_table_t cifs_mount_option_tokens = {

	{ Opt_user_xattr, "user_xattr" },
	{ Opt_nouser_xattr, "nouser_xattr" },
	{ Opt_forceuid, "forceuid" },
	{ Opt_noforceuid, "noforceuid" },
	{ Opt_forcegid, "forcegid" },
	{ Opt_noforcegid, "noforcegid" },
	{ Opt_noblocksend, "noblocksend" },
	{ Opt_noautotune, "noautotune" },
	{ Opt_hard, "hard" },
	{ Opt_soft, "soft" },
	{ Opt_perm, "perm" },
	{ Opt_noperm, "noperm" },
	{ Opt_mapchars, "mapchars" }, /* SFU style */
	{ Opt_nomapchars, "nomapchars" },
	{ Opt_mapposix, "mapposix" }, /* SFM style */
	{ Opt_nomapposix, "nomapposix" },
	{ Opt_sfu, "sfu" },
	{ Opt_nosfu, "nosfu" },
	{ Opt_nodfs, "nodfs" },
	{ Opt_posixpaths, "posixpaths" },
	{ Opt_noposixpaths, "noposixpaths" },
	{ Opt_nounix, "nounix" },
	{ Opt_nounix, "nolinux" },
	{ Opt_nocase, "nocase" },
	{ Opt_nocase, "ignorecase" },
	{ Opt_brl, "brl" },
	{ Opt_nobrl, "nobrl" },
	{ Opt_nobrl, "nolock" },
	{ Opt_forcemandatorylock, "forcemandatorylock" },
	{ Opt_forcemandatorylock, "forcemand" },
	{ Opt_setuids, "setuids" },
	{ Opt_nosetuids, "nosetuids" },
	{ Opt_setuidfromacl, "idsfromsid" },
	{ Opt_dynperm, "dynperm" },
	{ Opt_nodynperm, "nodynperm" },
	{ Opt_nohard, "nohard" },
	{ Opt_nosoft, "nosoft" },
	{ Opt_nointr, "nointr" },
	{ Opt_intr, "intr" },
	{ Opt_nostrictsync, "nostrictsync" },
	{ Opt_strictsync, "strictsync" },
	{ Opt_serverino, "serverino" },
	{ Opt_noserverino, "noserverino" },
	{ Opt_rwpidforward, "rwpidforward" },
	{ Opt_cifsacl, "cifsacl" },
	{ Opt_nocifsacl, "nocifsacl" },
	{ Opt_acl, "acl" },
	{ Opt_noacl, "noacl" },
	{ Opt_locallease, "locallease" },
	{ Opt_sign, "sign" },
	{ Opt_seal, "seal" },
	{ Opt_noac, "noac" },
	{ Opt_fsc, "fsc" },
	{ Opt_mfsymlinks, "mfsymlinks" },
	{ Opt_multiuser, "multiuser" },
	{ Opt_sloppy, "sloppy" },
	{ Opt_nosharesock, "nosharesock" },
	{ Opt_persistent, "persistenthandles"},
	{ Opt_nopersistent, "nopersistenthandles"},
	{ Opt_resilient, "resilienthandles"},
	{ Opt_noresilient, "noresilienthandles"},
	{ Opt_domainauto, "domainauto"},

	{ Opt_backupuid, "backupuid=%s" },
	{ Opt_backupgid, "backupgid=%s" },
	{ Opt_uid, "uid=%s" },
	{ Opt_cruid, "cruid=%s" },
	{ Opt_gid, "gid=%s" },
	{ Opt_file_mode, "file_mode=%s" },
	{ Opt_dirmode, "dirmode=%s" },
	{ Opt_dirmode, "dir_mode=%s" },
	{ Opt_port, "port=%s" },
	{ Opt_rsize, "rsize=%s" },
	{ Opt_wsize, "wsize=%s" },
	{ Opt_actimeo, "actimeo=%s" },
	{ Opt_echo_interval, "echo_interval=%s" },
	{ Opt_max_credits, "max_credits=%s" },
	{ Opt_snapshot, "snapshot=%s" },

	{ Opt_blank_user, "user=" },
	{ Opt_blank_user, "username=" },
	{ Opt_user, "user=%s" },
	{ Opt_user, "username=%s" },
	{ Opt_blank_pass, "pass=" },
	{ Opt_blank_pass, "password=" },
	{ Opt_pass, "pass=%s" },
	{ Opt_pass, "password=%s" },
	{ Opt_blank_ip, "ip=" },
	{ Opt_blank_ip, "addr=" },
	{ Opt_ip, "ip=%s" },
	{ Opt_ip, "addr=%s" },
	{ Opt_ignore, "unc=%s" },
	{ Opt_ignore, "target=%s" },
	{ Opt_ignore, "path=%s" },
	{ Opt_domain, "dom=%s" },
	{ Opt_domain, "domain=%s" },
	{ Opt_domain, "workgroup=%s" },
	{ Opt_srcaddr, "srcaddr=%s" },
	{ Opt_ignore, "prefixpath=%s" },
	{ Opt_iocharset, "iocharset=%s" },
	{ Opt_netbiosname, "netbiosname=%s" },
	{ Opt_servern, "servern=%s" },
	{ Opt_ver, "ver=%s" },
	{ Opt_vers, "vers=%s" },
	{ Opt_sec, "sec=%s" },
	{ Opt_cache, "cache=%s" },

	{ Opt_ignore, "cred" },
	{ Opt_ignore, "credentials" },
	{ Opt_ignore, "cred=%s" },
	{ Opt_ignore, "credentials=%s" },
	{ Opt_ignore, "guest" },
	{ Opt_ignore, "rw" },
	{ Opt_ignore, "ro" },
	{ Opt_ignore, "suid" },
	{ Opt_ignore, "nosuid" },
	{ Opt_ignore, "exec" },
	{ Opt_ignore, "noexec" },
	{ Opt_ignore, "nodev" },
	{ Opt_ignore, "noauto" },
	{ Opt_ignore, "dev" },
	{ Opt_ignore, "mand" },
	{ Opt_ignore, "nomand" },
	{ Opt_ignore, "_netdev" },

	{ Opt_err, NULL }
};

enum {
	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
	Opt_sec_ntlmsspi, Opt_sec_ntlmssp,
	Opt_ntlm, Opt_sec_ntlmi, Opt_sec_ntlmv2,
	Opt_sec_ntlmv2i, Opt_sec_lanman,
	Opt_sec_none,

	Opt_sec_err
};

static const match_table_t cifs_secflavor_tokens = {
	{ Opt_sec_krb5, "krb5" },
	{ Opt_sec_krb5i, "krb5i" },
	{ Opt_sec_krb5p, "krb5p" },
	{ Opt_sec_ntlmsspi, "ntlmsspi" },
	{ Opt_sec_ntlmssp, "ntlmssp" },
	{ Opt_ntlm, "ntlm" },
	{ Opt_sec_ntlmi, "ntlmi" },
	{ Opt_sec_ntlmv2, "nontlm" },
	{ Opt_sec_ntlmv2, "ntlmv2" },
	{ Opt_sec_ntlmv2i, "ntlmv2i" },
	{ Opt_sec_lanman, "lanman" },
	{ Opt_sec_none, "none" },

	{ Opt_sec_err, NULL }
};

/* cache flavors */
enum {
	Opt_cache_loose,
	Opt_cache_strict,
	Opt_cache_none,
	Opt_cache_err
};

static const match_table_t cifs_cacheflavor_tokens = {
	{ Opt_cache_loose, "loose" },
	{ Opt_cache_strict, "strict" },
	{ Opt_cache_none, "none" },
	{ Opt_cache_err, NULL }
};

static const match_table_t cifs_smb_version_tokens = {
	{ Smb_1, SMB1_VERSION_STRING },
	{ Smb_20, SMB20_VERSION_STRING},
	{ Smb_21, SMB21_VERSION_STRING },
	{ Smb_30, SMB30_VERSION_STRING },
	{ Smb_302, SMB302_VERSION_STRING },
#ifdef CONFIG_CIFS_SMB311
	{ Smb_311, SMB311_VERSION_STRING },
	{ Smb_311, ALT_SMB311_VERSION_STRING },
#endif /* SMB311 */
	{ Smb_version_err, NULL }
};

static int ip_connect(struct TCP_Server_Info *server);
static int generic_ip_connect(struct TCP_Server_Info *server);
static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
static void cifs_prune_tlinks(struct work_struct *work);
static int cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
					const char *devname);

/*
 * cifs tcp session reconnection
 *
 * mark tcp session as reconnecting so temporarily locked
 * mark all smb sessions as reconnecting for tcp session
 * reconnect tcp session
 * wake up waiters on reconnection? - (not needed currently)
 */
int
cifs_reconnect(struct TCP_Server_Info *server)
{
	int rc = 0;
	struct list_head *tmp, *tmp2;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct mid_q_entry *mid_entry;
	struct list_head retry_list;

	spin_lock(&GlobalMid_Lock);
	if (server->tcpStatus == CifsExiting) {
		/* the demux thread will exit normally
		next time through the loop */
		spin_unlock(&GlobalMid_Lock);
		return rc;
	} else
		server->tcpStatus = CifsNeedReconnect;
	spin_unlock(&GlobalMid_Lock);
	server->maxBuf = 0;
#ifdef CONFIG_CIFS_SMB2
	server->max_read = 0;
#endif

	cifs_dbg(FYI, "Reconnecting tcp session\n");

	/* before reconnecting the tcp session, mark the smb session (uid)
		and the tid bad so they are not used until reconnected */
	cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n",
		 __func__);
	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &server->smb_ses_list) {
		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
		ses->need_reconnect = true;
		ses->ipc_tid = 0;
		list_for_each(tmp2, &ses->tcon_list) {
			tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
			tcon->need_reconnect = true;
		}
	}
	spin_unlock(&cifs_tcp_ses_lock);

	/* do not want to be sending data on a socket we are freeing */
	cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
	mutex_lock(&server->srv_mutex);
	if (server->ssocket) {
		cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n",
			 server->ssocket->state, server->ssocket->flags);
		kernel_sock_shutdown(server->ssocket, SHUT_WR);
		cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n",
			 server->ssocket->state, server->ssocket->flags);
		sock_release(server->ssocket);
		server->ssocket = NULL;
	}
	server->sequence_number = 0;
	server->session_estab = false;
	kfree(server->session_key.response);
	server->session_key.response = NULL;
	server->session_key.len = 0;
	server->lstrp = jiffies;

	/* mark submitted MIDs for retry and issue callback */
	INIT_LIST_HEAD(&retry_list);
	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
	spin_lock(&GlobalMid_Lock);
	list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
		if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
			mid_entry->mid_state = MID_RETRY_NEEDED;
		list_move(&mid_entry->qhead, &retry_list);
	}
	spin_unlock(&GlobalMid_Lock);
	mutex_unlock(&server->srv_mutex);

	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
	list_for_each_safe(tmp, tmp2, &retry_list) {
		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
		list_del_init(&mid_entry->qhead);
		mid_entry->callback(mid_entry);
	}

	do {
		try_to_freeze();

		/* we should try only the port we connected to before */
		mutex_lock(&server->srv_mutex);
		rc = generic_ip_connect(server);
		if (rc) {
			cifs_dbg(FYI, "reconnect error %d\n", rc);
			mutex_unlock(&server->srv_mutex);
			msleep(3000);
		} else {
			atomic_inc(&tcpSesReconnectCount);
			spin_lock(&GlobalMid_Lock);
			if (server->tcpStatus != CifsExiting)
				server->tcpStatus = CifsNeedNegotiate;
			spin_unlock(&GlobalMid_Lock);
			mutex_unlock(&server->srv_mutex);
		}
	} while (server->tcpStatus == CifsNeedReconnect);

	if (server->tcpStatus == CifsNeedNegotiate)
		mod_delayed_work(cifsiod_wq, &server->echo, 0);

	return rc;
}

static void
cifs_echo_request(struct work_struct *work)
{
	int rc;
	struct TCP_Server_Info *server = container_of(work,
					struct TCP_Server_Info, echo.work);
	unsigned long echo_interval;

	/*
	 * If we need to renegotiate, set echo interval to zero to
	 * immediately call echo service where we can renegotiate.
	 */
	if (server->tcpStatus == CifsNeedNegotiate)
		echo_interval = 0;
	else
		echo_interval = server->echo_interval;

	/*
	 * We cannot send an echo if it is disabled.
	 * Also, no need to ping if we got a response recently.
	 */

	if (server->tcpStatus == CifsNeedReconnect ||
	    server->tcpStatus == CifsExiting ||
	    server->tcpStatus == CifsNew ||
	    (server->ops->can_echo && !server->ops->can_echo(server)) ||
	    time_before(jiffies, server->lstrp + echo_interval - HZ))
		goto requeue_echo;

	rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
	if (rc)
		cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
			 server->hostname);

requeue_echo:
	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
}

static bool
allocate_buffers(struct TCP_Server_Info *server)
{
	if (!server->bigbuf) {
		server->bigbuf = (char *)cifs_buf_get();
		if (!server->bigbuf) {
			cifs_dbg(VFS, "No memory for large SMB response\n");
			msleep(3000);
			/* retry will check if exiting */
			return false;
		}
	} else if (server->large_buf) {
		/* we are reusing a dirty large buf, clear its start */
		memset(server->bigbuf, 0, HEADER_SIZE(server));
	}

	if (!server->smallbuf) {
		server->smallbuf = (char *)cifs_small_buf_get();
		if (!server->smallbuf) {
			cifs_dbg(VFS, "No memory for SMB response\n");
			msleep(1000);
			/* retry will check if exiting */
			return false;
		}
		/* beginning of smb buffer is cleared in our buf_get */
	} else {
		/* if existing small buf clear beginning */
		memset(server->smallbuf, 0, HEADER_SIZE(server));
	}

	return true;
}

static bool
server_unresponsive(struct TCP_Server_Info *server)
{
	/*
	 * We need to wait 2 echo intervals to make sure we handle such
	 * situations right:
	 * 1s  client sends a normal SMB request
	 * 2s  client gets a response
	 * 30s echo workqueue job pops, and decides we got a response recently
	 *     and don't need to send another
	 * ...
	 * 65s kernel_recvmsg times out, and we see that we haven't gotten
	 *     a response in >60s.
	 */
	if (server->tcpStatus == CifsGood &&
	    time_after(jiffies, server->lstrp + 2 * server->echo_interval)) {
		cifs_dbg(VFS, "Server %s has not responded in %lu seconds. Reconnecting...\n",
			 server->hostname, (2 * server->echo_interval) / HZ);
		cifs_reconnect(server);
		wake_up(&server->response_q);
		return true;
	}

	return false;
}

static int
cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
{
	int length = 0;
	int total_read;

	smb_msg->msg_control = NULL;
	smb_msg->msg_controllen = 0;

	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
		try_to_freeze();

		if (server_unresponsive(server))
			return -ECONNABORTED;

		length = sock_recvmsg(server->ssocket, smb_msg, 0);

		if (server->tcpStatus == CifsExiting)
			return -ESHUTDOWN;

		if (server->tcpStatus == CifsNeedReconnect) {
			cifs_reconnect(server);
			return -ECONNABORTED;
		}

		if (length == -ERESTARTSYS ||
		    length == -EAGAIN ||
		    length == -EINTR) {
			/*
			 * Minimum sleep to prevent looping, allowing socket
			 * to clear and app threads to set tcpStatus
			 * CifsNeedReconnect if server hung.
			 */
			usleep_range(1000, 2000);
			length = 0;
			continue;
		}

		if (length <= 0) {
			cifs_dbg(FYI, "Received no data or error: %d\n", length);
			cifs_reconnect(server);
			return -ECONNABORTED;
		}
	}
	return total_read;
}

int
cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
		      unsigned int to_read)
{
	struct msghdr smb_msg;
	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);

	return cifs_readv_from_socket(server, &smb_msg);
}

int
cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
		      unsigned int to_read)
{
	struct msghdr smb_msg;
	struct bio_vec bv = {.bv_page = page, .bv_len = to_read};
	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
	return cifs_readv_from_socket(server, &smb_msg);
}

static bool
is_smb_response(struct TCP_Server_Info *server, unsigned char type)
{
	/*
	 * The first byte big endian of the length field,
	 * is actually not part of the length but the type
	 * with the most common, zero, as regular data.
	 */
	switch (type) {
	case RFC1002_SESSION_MESSAGE:
		/* Regular SMB response */
		return true;
	case RFC1002_SESSION_KEEP_ALIVE:
		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
		break;
	case RFC1002_POSITIVE_SESSION_RESPONSE:
		cifs_dbg(FYI, "RFC 1002 positive session response\n");
		break;
	case RFC1002_NEGATIVE_SESSION_RESPONSE:
		/*
		 * We get this from Windows 98 instead of an error on
		 * SMB negprot response.
		 */
		cifs_dbg(FYI, "RFC 1002 negative session response\n");
		/* give server a second to clean up */
		msleep(1000);
		/*
		 * Always try 445 first on reconnect since we get NACK
		 * on some if we ever connected to port 139 (the NACK
		 * is since we do not begin with RFC1001 session
		 * initialize frame).
		 */
		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
		cifs_reconnect(server);
		wake_up(&server->response_q);
		break;
	default:
		cifs_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
		cifs_reconnect(server);
	}

	return false;
}

void
dequeue_mid(struct mid_q_entry *mid, bool malformed)
{
#ifdef CONFIG_CIFS_STATS2
	mid->when_received = jiffies;
#endif
	spin_lock(&GlobalMid_Lock);
	if (!malformed)
		mid->mid_state = MID_RESPONSE_RECEIVED;
	else
		mid->mid_state = MID_RESPONSE_MALFORMED;
	list_del_init(&mid->qhead);
	spin_unlock(&GlobalMid_Lock);
}

static void
handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
	   char *buf, int malformed)
{
	if (server->ops->check_trans2 &&
	    server->ops->check_trans2(mid, server, buf, malformed))
		return;
	mid->resp_buf = buf;
	mid->large_buf = server->large_buf;
	/* Was previous buf put in mpx struct for multi-rsp? */
	if (!mid->multiRsp) {
		/* smb buffer will be freed by user thread */
		if (server->large_buf)
			server->bigbuf = NULL;
		else
			server->smallbuf = NULL;
	}
	dequeue_mid(mid, malformed);
}

static void clean_demultiplex_info(struct TCP_Server_Info *server)
{
	int length;

	/* take it off the list, if it's not already */
	spin_lock(&cifs_tcp_ses_lock);
	list_del_init(&server->tcp_ses_list);
	spin_unlock(&cifs_tcp_ses_lock);

	spin_lock(&GlobalMid_Lock);
	server->tcpStatus = CifsExiting;
	spin_unlock(&GlobalMid_Lock);
	wake_up_all(&server->response_q);

	/* check if we have blocked requests that need to free */
	spin_lock(&server->req_lock);
	if (server->credits <= 0)
		server->credits = 1;
	spin_unlock(&server->req_lock);
	/*
	 * Although there should not be any requests blocked on this queue it
	 * can not hurt to be paranoid and try to wake up requests that may
	 * haven been blocked when more than 50 at time were on the wire to the
	 * same server - they now will see the session is in exit state and get
	 * out of SendReceive.
	 */
	wake_up_all(&server->request_q);
	/* give those requests time to exit */
	msleep(125);

	if (server->ssocket) {
		sock_release(server->ssocket);
		server->ssocket = NULL;
	}

	if (!list_empty(&server->pending_mid_q)) {
		struct list_head dispose_list;
		struct mid_q_entry *mid_entry;
		struct list_head *tmp, *tmp2;

		INIT_LIST_HEAD(&dispose_list);
		spin_lock(&GlobalMid_Lock);
		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
			cifs_dbg(FYI, "Clearing mid 0x%llx\n", mid_entry->mid);
			mid_entry->mid_state = MID_SHUTDOWN;
			list_move(&mid_entry->qhead, &dispose_list);
		}
		spin_unlock(&GlobalMid_Lock);

		/* now walk dispose list and issue callbacks */
		list_for_each_safe(tmp, tmp2, &dispose_list) {
			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
			cifs_dbg(FYI, "Callback mid 0x%llx\n", mid_entry->mid);
			list_del_init(&mid_entry->qhead);
			mid_entry->callback(mid_entry);
		}
		/* 1/8th of sec is more than enough time for them to exit */
		msleep(125);
	}

	if (!list_empty(&server->pending_mid_q)) {
		/*
		 * mpx threads have not exited yet give them at least the smb
		 * send timeout time for long ops.
		 *
		 * Due to delays on oplock break requests, we need to wait at
		 * least 45 seconds before giving up on a request getting a
		 * response and going ahead and killing cifsd.
		 */
		cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
		msleep(46000);
		/*
		 * If threads still have not exited they are probably never
		 * coming home not much else we can do but free the memory.
		 */
	}

	kfree(server->hostname);
	kfree(server);

	length = atomic_dec_return(&tcpSesAllocCount);
	if (length > 0)
		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
}

static int
standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
	int length;
	char *buf = server->smallbuf;
	unsigned int pdu_length = get_rfc1002_length(buf);

	/* make sure this will fit in a large buffer */
	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) - 4) {
		cifs_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
		cifs_reconnect(server);
		wake_up(&server->response_q);
		return -ECONNABORTED;
	}

	/* switch to large buffer if too big for a small one */
	if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
		server->large_buf = true;
		memcpy(server->bigbuf, buf, server->total_read);
		buf = server->bigbuf;
	}

	/* now read the rest */
	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
				pdu_length - HEADER_SIZE(server) + 1 + 4);
	if (length < 0)
		return length;
	server->total_read += length;

	dump_smb(buf, server->total_read);

	return cifs_handle_standard(server, mid);
}

int
cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
	int length;

	/*
	 * We know that we received enough to get to the MID as we
	 * checked the pdu_length earlier. Now check to see
	 * if the rest of the header is OK. We borrow the length
	 * var for the rest of the loop to avoid a new stack var.
	 *
	 * 48 bytes is enough to display the header and a little bit
	 * into the payload for debugging purposes.
	 */
	length = server->ops->check_message(buf, server->total_read, server);
	if (length != 0)
		cifs_dump_mem("Bad SMB: ", buf,
			min_t(unsigned int, server->total_read, 48));

	if (server->ops->is_status_pending &&
	    server->ops->is_status_pending(buf, server, length))
		return -1;

	if (!mid)
		return length;

	handle_mid(mid, server, buf, length);
	return 0;
}

static int
cifs_demultiplex_thread(void *p)
{
	int length;
	struct TCP_Server_Info *server = p;
	unsigned int pdu_length;
	char *buf = NULL;
	struct task_struct *task_to_wake = NULL;
	struct mid_q_entry *mid_entry;

	current->flags |= PF_MEMALLOC;
	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));

	length = atomic_inc_return(&tcpSesAllocCount);
	if (length > 1)
		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);

	set_freezable();
	while (server->tcpStatus != CifsExiting) {
		if (try_to_freeze())
			continue;

		if (!allocate_buffers(server))
			continue;

		server->large_buf = false;
		buf = server->smallbuf;
		pdu_length = 4; /* enough to get RFC1001 header */

		length = cifs_read_from_socket(server, buf, pdu_length);
		if (length < 0)
			continue;
		server->total_read = length;

		/*
		 * The right amount was read from socket - 4 bytes,
		 * so we can now interpret the length field.
		 */
		pdu_length = get_rfc1002_length(buf);

		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
		if (!is_smb_response(server, buf[0]))
			continue;

		/* make sure we have enough to get to the MID */
		if (pdu_length < HEADER_SIZE(server) - 1 - 4) {
			cifs_dbg(VFS, "SMB response too short (%u bytes)\n",
				 pdu_length);
			cifs_reconnect(server);
			wake_up(&server->response_q);
			continue;
		}

		/* read down to the MID */
		length = cifs_read_from_socket(server, buf + 4,
					       HEADER_SIZE(server) - 1 - 4);
		if (length < 0)
			continue;
		server->total_read += length;

		if (server->ops->is_transform_hdr &&
		    server->ops->receive_transform &&
		    server->ops->is_transform_hdr(buf)) {
			length = server->ops->receive_transform(server,
								&mid_entry);
		} else {
			mid_entry = server->ops->find_mid(server, buf);

			if (!mid_entry || !mid_entry->receive)
				length = standard_receive3(server, mid_entry);
			else
				length = mid_entry->receive(server, mid_entry);
		}

		if (length < 0)
			continue;

		if (server->large_buf)
			buf = server->bigbuf;

		server->lstrp = jiffies;
		if (mid_entry != NULL) {
			if ((mid_entry->mid_flags & MID_WAIT_CANCELLED) &&
			     mid_entry->mid_state == MID_RESPONSE_RECEIVED &&
					server->ops->handle_cancelled_mid)
				server->ops->handle_cancelled_mid(
							mid_entry->resp_buf,
							server);

			if (!mid_entry->multiRsp || mid_entry->multiEnd)
				mid_entry->callback(mid_entry);
		} else if (server->ops->is_oplock_break &&
			   server->ops->is_oplock_break(buf, server)) {
			cifs_dbg(FYI, "Received oplock break\n");
		} else {
			cifs_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
				 atomic_read(&midCount));
			cifs_dump_mem("Received Data is: ", buf,
				      HEADER_SIZE(server));
#ifdef CONFIG_CIFS_DEBUG2
			if (server->ops->dump_detail)
				server->ops->dump_detail(buf);
			cifs_dump_mids(server);
#endif /* CIFS_DEBUG2 */

		}
	} /* end while !EXITING */

	/* buffer usually freed in free_mid - need to free it here on exit */
	cifs_buf_release(server->bigbuf);
	if (server->smallbuf) /* no sense logging a debug message if NULL */
		cifs_small_buf_release(server->smallbuf);

	task_to_wake = xchg(&server->tsk, NULL);
	clean_demultiplex_info(server);

	/* if server->tsk was NULL then wait for a signal before exiting */
	if (!task_to_wake) {
		set_current_state(TASK_INTERRUPTIBLE);
		while (!signal_pending(current)) {
			schedule();
			set_current_state(TASK_INTERRUPTIBLE);
		}
		set_current_state(TASK_RUNNING);
	}

	module_put_and_exit(0);
}

/* extract the host portion of the UNC string */
static char *
extract_hostname(const char *unc)
{
	const char *src;
	char *dst, *delim;
	unsigned int len;

	/* skip double chars at beginning of string */
	/* BB: check validity of these bytes? */
	src = unc + 2;

	/* delimiter between hostname and sharename is always '\\' now */
	delim = strchr(src, '\\');
	if (!delim)
		return ERR_PTR(-EINVAL);

	len = delim - src;
	dst = kmalloc((len + 1), GFP_KERNEL);
	if (dst == NULL)
		return ERR_PTR(-ENOMEM);

	memcpy(dst, src, len);
	dst[len] = '\0';

	return dst;
}

static int get_option_ul(substring_t args[], unsigned long *option)
{
	int rc;
	char *string;

	string = match_strdup(args);
	if (string == NULL)
		return -ENOMEM;
	rc = kstrtoul(string, 0, option);
	kfree(string);

	return rc;
}

static int get_option_uid(substring_t args[], kuid_t *result)
{
	unsigned long value;
	kuid_t uid;
	int rc;

	rc = get_option_ul(args, &value);
	if (rc)
		return rc;

	uid = make_kuid(current_user_ns(), value);
	if (!uid_valid(uid))
		return -EINVAL;

	*result = uid;
	return 0;
}

static int get_option_gid(substring_t args[], kgid_t *result)
{
	unsigned long value;
	kgid_t gid;
	int rc;

	rc = get_option_ul(args, &value);
	if (rc)
		return rc;

	gid = make_kgid(current_user_ns(), value);
	if (!gid_valid(gid))
		return -EINVAL;

	*result = gid;
	return 0;
}

static int cifs_parse_security_flavors(char *value,
				       struct smb_vol *vol)
{

	substring_t args[MAX_OPT_ARGS];

	/*
	 * With mount options, the last one should win. Reset any existing
	 * settings back to default.
	 */
	vol->sectype = Unspecified;
	vol->sign = false;

	switch (match_token(value, cifs_secflavor_tokens, args)) {
	case Opt_sec_krb5p:
		cifs_dbg(VFS, "sec=krb5p is not supported!\n");
		return 1;
	case Opt_sec_krb5i:
		vol->sign = true;
		/* Fallthrough */
	case Opt_sec_krb5:
		vol->sectype = Kerberos;
		break;
	case Opt_sec_ntlmsspi:
		vol->sign = true;
		/* Fallthrough */
	case Opt_sec_ntlmssp:
		vol->sectype = RawNTLMSSP;
		break;
	case Opt_sec_ntlmi:
		vol->sign = true;
		/* Fallthrough */
	case Opt_ntlm:
		vol->sectype = NTLM;
		break;
	case Opt_sec_ntlmv2i:
		vol->sign = true;
		/* Fallthrough */
	case Opt_sec_ntlmv2:
		vol->sectype = NTLMv2;
		break;
#ifdef CONFIG_CIFS_WEAK_PW_HASH
	case Opt_sec_lanman:
		vol->sectype = LANMAN;
		break;
#endif
	case Opt_sec_none:
		vol->nullauth = 1;
		break;
	default:
		cifs_dbg(VFS, "bad security option: %s\n", value);
		return 1;
	}

	return 0;
}

static int
cifs_parse_cache_flavor(char *value, struct smb_vol *vol)
{
	substring_t args[MAX_OPT_ARGS];

	switch (match_token(value, cifs_cacheflavor_tokens, args)) {
	case Opt_cache_loose:
		vol->direct_io = false;
		vol->strict_io = false;
		break;
	case Opt_cache_strict:
		vol->direct_io = false;
		vol->strict_io = true;
		break;
	case Opt_cache_none:
		vol->direct_io = true;
		vol->strict_io = false;
		break;
	default:
		cifs_dbg(VFS, "bad cache= option: %s\n", value);
		return 1;
	}
	return 0;
}

static int
cifs_parse_smb_version(char *value, struct smb_vol *vol)
{
	substring_t args[MAX_OPT_ARGS];

	switch (match_token(value, cifs_smb_version_tokens, args)) {
	case Smb_1:
		vol->ops = &smb1_operations;
		vol->vals = &smb1_values;
		break;
#ifdef CONFIG_CIFS_SMB2
	case Smb_20:
		vol->ops = &smb20_operations;
		vol->vals = &smb20_values;
		break;
	case Smb_21:
		vol->ops = &smb21_operations;
		vol->vals = &smb21_values;
		break;
	case Smb_30:
		vol->ops = &smb30_operations;
		vol->vals = &smb30_values;
		break;
	case Smb_302:
		vol->ops = &smb30_operations; /* currently identical with 3.0 */
		vol->vals = &smb302_values;
		break;
#ifdef CONFIG_CIFS_SMB311
	case Smb_311:
		vol->ops = &smb311_operations;
		vol->vals = &smb311_values;
		break;
#endif /* SMB311 */
#endif
	default:
		cifs_dbg(VFS, "Unknown vers= option specified: %s\n", value);
		return 1;
	}
	return 0;
}

/*
 * Parse a devname into substrings and populate the vol->UNC and vol->prepath
 * fields with the result. Returns 0 on success and an error otherwise.
 */
static int
cifs_parse_devname(const char *devname, struct smb_vol *vol)
{
	char *pos;
	const char *delims = "/\\";
	size_t len;

	/* make sure we have a valid UNC double delimiter prefix */
	len = strspn(devname, delims);
	if (len != 2)
		return -EINVAL;

	/* find delimiter between host and sharename */
	pos = strpbrk(devname + 2, delims);
	if (!pos)
		return -EINVAL;

	/* skip past delimiter */
	++pos;

	/* now go until next delimiter or end of string */
	len = strcspn(pos, delims);

	/* move "pos" up to delimiter or NULL */
	pos += len;
	vol->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
	if (!vol->UNC)
		return -ENOMEM;

	convert_delimiter(vol->UNC, '\\');

	/* skip any delimiter */
	if (*pos == '/' || *pos == '\\')
		pos++;

	/* If pos is NULL then no prepath */
	if (!*pos)
		return 0;

	vol->prepath = kstrdup(pos, GFP_KERNEL);
	if (!vol->prepath)
		return -ENOMEM;

	return 0;
}

static int
cifs_parse_mount_options(const char *mountdata, const char *devname,
			 struct smb_vol *vol)
{
	char *data, *end;
	char *mountdata_copy = NULL, *options;
	unsigned int  temp_len, i, j;
	char separator[2];
	short int override_uid = -1;
	short int override_gid = -1;
	bool uid_specified = false;
	bool gid_specified = false;
	bool sloppy = false;
	char *invalid = NULL;
	char *nodename = utsname()->nodename;
	char *string = NULL;
	char *tmp_end, *value;
	char delim;
	bool got_ip = false;
	unsigned short port = 0;
	struct sockaddr *dstaddr = (struct sockaddr *)&vol->dstaddr;

	separator[0] = ',';
	separator[1] = 0;
	delim = separator[0];

	/* ensure we always start with zeroed-out smb_vol */
	memset(vol, 0, sizeof(*vol));

	/*
	 * does not have to be perfect mapping since field is
	 * informational, only used for servers that do not support
	 * port 445 and it can be overridden at mount time
	 */
	memset(vol->source_rfc1001_name, 0x20, RFC1001_NAME_LEN);
	for (i = 0; i < strnlen(nodename, RFC1001_NAME_LEN); i++)
		vol->source_rfc1001_name[i] = toupper(nodename[i]);

	vol->source_rfc1001_name[RFC1001_NAME_LEN] = 0;
	/* null target name indicates to use *SMBSERVR default called name
	   if we end up sending RFC1001 session initialize */
	vol->target_rfc1001_name[0] = 0;
	vol->cred_uid = current_uid();
	vol->linux_uid = current_uid();
	vol->linux_gid = current_gid();

	/*
	 * default to SFM style remapping of seven reserved characters
	 * unless user overrides it or we negotiate CIFS POSIX where
	 * it is unnecessary.  Can not simultaneously use more than one mapping
	 * since then readdir could list files that open could not open
	 */
	vol->remap = true;

	/* default to only allowing write access to owner of the mount */
	vol->dir_mode = vol->file_mode = S_IRUGO | S_IXUGO | S_IWUSR;

	/* vol->retry default is 0 (i.e. "soft" limited retry not hard retry) */
	/* default is always to request posix paths. */
	vol->posix_paths = 1;
	/* default to using server inode numbers where available */
	vol->server_ino = 1;

	/* default is to use strict cifs caching semantics */
	vol->strict_io = true;

	vol->actimeo = CIFS_DEF_ACTIMEO;

	/* FIXME: add autonegotiation -- for now, SMB1 is default */
	vol->ops = &smb1_operations;
	vol->vals = &smb1_values;

	vol->echo_interval = SMB_ECHO_INTERVAL_DEFAULT;

	if (!mountdata)
		goto cifs_parse_mount_err;

	mountdata_copy = kstrndup(mountdata, PAGE_SIZE, GFP_KERNEL);
	if (!mountdata_copy)
		goto cifs_parse_mount_err;

	options = mountdata_copy;
	end = options + strlen(options);

	if (strncmp(options, "sep=", 4) == 0) {
		if (options[4] != 0) {
			separator[0] = options[4];
			options += 5;
		} else {
			cifs_dbg(FYI, "Null separator not allowed\n");
		}
	}
	vol->backupuid_specified = false; /* no backup intent for a user */
	vol->backupgid_specified = false; /* no backup intent for a group */

	switch (cifs_parse_devname(devname, vol)) {
	case 0:
		break;
	case -ENOMEM:
		cifs_dbg(VFS, "Unable to allocate memory for devname.\n");
		goto cifs_parse_mount_err;
	case -EINVAL:
		cifs_dbg(VFS, "Malformed UNC in devname.\n");
		goto cifs_parse_mount_err;
	default:
		cifs_dbg(VFS, "Unknown error parsing devname.\n");
		goto cifs_parse_mount_err;
	}

	while ((data = strsep(&options, separator)) != NULL) {
		substring_t args[MAX_OPT_ARGS];
		unsigned long option;
		int token;

		if (!*data)
			continue;

		token = match_token(data, cifs_mount_option_tokens, args);

		switch (token) {

		/* Ingnore the following */
		case Opt_ignore:
			break;

		/* Boolean values */
		case Opt_user_xattr:
			vol->no_xattr = 0;
			break;
		case Opt_nouser_xattr:
			vol->no_xattr = 1;
			break;
		case Opt_forceuid:
			override_uid = 1;
			break;
		case Opt_noforceuid:
			override_uid = 0;
			break;
		case Opt_forcegid:
			override_gid = 1;
			break;
		case Opt_noforcegid:
			override_gid = 0;
			break;
		case Opt_noblocksend:
			vol->noblocksnd = 1;
			break;
		case Opt_noautotune:
			vol->noautotune = 1;
			break;
		case Opt_hard:
			vol->retry = 1;
			break;
		case Opt_soft:
			vol->retry = 0;
			break;
		case Opt_perm:
			vol->noperm = 0;
			break;
		case Opt_noperm:
			vol->noperm = 1;
			break;
		case Opt_mapchars:
			vol->sfu_remap = true;
			vol->remap = false; /* disable SFM mapping */
			break;
		case Opt_nomapchars:
			vol->sfu_remap = false;
			break;
		case Opt_mapposix:
			vol->remap = true;
			vol->sfu_remap = false; /* disable SFU mapping */
			break;
		case Opt_nomapposix:
			vol->remap = false;
			break;
		case Opt_sfu:
			vol->sfu_emul = 1;
			break;
		case Opt_nosfu:
			vol->sfu_emul = 0;
			break;
		case Opt_nodfs:
			vol->nodfs = 1;
			break;
		case Opt_posixpaths:
			vol->posix_paths = 1;
			break;
		case Opt_noposixpaths:
			vol->posix_paths = 0;
			break;
		case Opt_nounix:
			vol->no_linux_ext = 1;
			break;
		case Opt_nocase:
			vol->nocase = 1;
			break;
		case Opt_brl:
			vol->nobrl =  0;
			break;
		case Opt_nobrl:
			vol->nobrl =  1;
			/*
			 * turn off mandatory locking in mode
			 * if remote locking is turned off since the
			 * local vfs will do advisory
			 */
			if (vol->file_mode ==
				(S_IALLUGO & ~(S_ISUID | S_IXGRP)))
				vol->file_mode = S_IALLUGO;
			break;
		case Opt_forcemandatorylock:
			vol->mand_lock = 1;
			break;
		case Opt_setuids:
			vol->setuids = 1;
			break;
		case Opt_nosetuids:
			vol->setuids = 0;
			break;
		case Opt_setuidfromacl:
			vol->setuidfromacl = 1;
			break;
		case Opt_dynperm:
			vol->dynperm = true;
			break;
		case Opt_nodynperm:
			vol->dynperm = false;
			break;
		case Opt_nohard:
			vol->retry = 0;
			break;
		case Opt_nosoft:
			vol->retry = 1;
			break;
		case Opt_nointr:
			vol->intr = 0;
			break;
		case Opt_intr:
			vol->intr = 1;
			break;
		case Opt_nostrictsync:
			vol->nostrictsync = 1;
			break;
		case Opt_strictsync:
			vol->nostrictsync = 0;
			break;
		case Opt_serverino:
			vol->server_ino = 1;
			break;
		case Opt_noserverino:
			vol->server_ino = 0;
			break;
		case Opt_rwpidforward:
			vol->rwpidforward = 1;
			break;
		case Opt_cifsacl:
			vol->cifs_acl = 1;
			break;
		case Opt_nocifsacl:
			vol->cifs_acl = 0;
			break;
		case Opt_acl:
			vol->no_psx_acl = 0;
			break;
		case Opt_noacl:
			vol->no_psx_acl = 1;
			break;
		case Opt_locallease:
			vol->local_lease = 1;
			break;
		case Opt_sign:
			vol->sign = true;
			break;
		case Opt_seal:
			/* we do not do the following in secFlags because seal
			 * is a per tree connection (mount) not a per socket
			 * or per-smb connection option in the protocol
			 * vol->secFlg |= CIFSSEC_MUST_SEAL;
			 */
			vol->seal = 1;
			break;
		case Opt_noac:
			pr_warn("CIFS: Mount option noac not supported. Instead set /proc/fs/cifs/LookupCacheEnabled to 0\n");
			break;
		case Opt_fsc:
#ifndef CONFIG_CIFS_FSCACHE
			cifs_dbg(VFS, "FS-Cache support needs CONFIG_CIFS_FSCACHE kernel config option set\n");
			goto cifs_parse_mount_err;
#endif
			vol->fsc = true;
			break;
		case Opt_mfsymlinks:
			vol->mfsymlinks = true;
			break;
		case Opt_multiuser:
			vol->multiuser = true;
			break;
		case Opt_sloppy:
			sloppy = true;
			break;
		case Opt_nosharesock:
			vol->nosharesock = true;
			break;
		case Opt_nopersistent:
			vol->nopersistent = true;
			if (vol->persistent) {
				cifs_dbg(VFS,
				  "persistenthandles mount options conflict\n");
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_persistent:
			vol->persistent = true;
			if ((vol->nopersistent) || (vol->resilient)) {
				cifs_dbg(VFS,
				  "persistenthandles mount options conflict\n");
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_resilient:
			vol->resilient = true;
			if (vol->persistent) {
				cifs_dbg(VFS,
				  "persistenthandles mount options conflict\n");
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_noresilient:
			vol->resilient = false; /* already the default */
			break;
		case Opt_domainauto:
			vol->domainauto = true;
			break;

		/* Numeric Values */
		case Opt_backupuid:
			if (get_option_uid(args, &vol->backupuid)) {
				cifs_dbg(VFS, "%s: Invalid backupuid value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->backupuid_specified = true;
			break;
		case Opt_backupgid:
			if (get_option_gid(args, &vol->backupgid)) {
				cifs_dbg(VFS, "%s: Invalid backupgid value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->backupgid_specified = true;
			break;
		case Opt_uid:
			if (get_option_uid(args, &vol->linux_uid)) {
				cifs_dbg(VFS, "%s: Invalid uid value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			uid_specified = true;
			break;
		case Opt_cruid:
			if (get_option_uid(args, &vol->cred_uid)) {
				cifs_dbg(VFS, "%s: Invalid cruid value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_gid:
			if (get_option_gid(args, &vol->linux_gid)) {
				cifs_dbg(VFS, "%s: Invalid gid value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			gid_specified = true;
			break;
		case Opt_file_mode:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid file_mode value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->file_mode = option;
			break;
		case Opt_dirmode:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid dir_mode value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->dir_mode = option;
			break;
		case Opt_port:
			if (get_option_ul(args, &option) ||
			    option > USHRT_MAX) {
				cifs_dbg(VFS, "%s: Invalid port value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			port = (unsigned short)option;
			break;
		case Opt_rsize:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid rsize value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->rsize = option;
			break;
		case Opt_wsize:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid wsize value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->wsize = option;
			break;
		case Opt_actimeo:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid actimeo value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->actimeo = HZ * option;
			if (vol->actimeo > CIFS_MAX_ACTIMEO) {
				cifs_dbg(VFS, "attribute cache timeout too large\n");
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_echo_interval:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid echo interval value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->echo_interval = option;
			break;
		case Opt_snapshot:
			if (get_option_ul(args, &option)) {
				cifs_dbg(VFS, "%s: Invalid snapshot time\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->snapshot_time = option;
			break;
		case Opt_max_credits:
			if (get_option_ul(args, &option) || (option < 20) ||
			    (option > 60000)) {
				cifs_dbg(VFS, "%s: Invalid max_credits value\n",
					 __func__);
				goto cifs_parse_mount_err;
			}
			vol->max_credits = option;
			break;

		/* String Arguments */

		case Opt_blank_user:
			/* null user, ie. anonymous authentication */
			vol->nullauth = 1;
			vol->username = NULL;
			break;
		case Opt_user:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (strnlen(string, CIFS_MAX_USERNAME_LEN) >
							CIFS_MAX_USERNAME_LEN) {
				pr_warn("CIFS: username too long\n");
				goto cifs_parse_mount_err;
			}

			kfree(vol->username);
			vol->username = kstrdup(string, GFP_KERNEL);
			if (!vol->username)
				goto cifs_parse_mount_err;
			break;
		case Opt_blank_pass:
			/* passwords have to be handled differently
			 * to allow the character used for deliminator
			 * to be passed within them
			 */

			/*
			 * Check if this is a case where the  password
			 * starts with a delimiter
			 */
			tmp_end = strchr(data, '=');
			tmp_end++;
			if (!(tmp_end < end && tmp_end[1] == delim)) {
				/* No it is not. Set the password to NULL */
				kfree(vol->password);
				vol->password = NULL;
				break;
			}
			/* Yes it is. Drop down to Opt_pass below.*/
		case Opt_pass:
			/* Obtain the value string */
			value = strchr(data, '=');
			value++;

			/* Set tmp_end to end of the string */
			tmp_end = (char *) value + strlen(value);

			/* Check if following character is the deliminator
			 * If yes, we have encountered a double deliminator
			 * reset the NULL character to the deliminator
			 */
			if (tmp_end < end && tmp_end[1] == delim) {
				tmp_end[0] = delim;

				/* Keep iterating until we get to a single
				 * deliminator OR the end
				 */
				while ((tmp_end = strchr(tmp_end, delim))
					!= NULL && (tmp_end[1] == delim)) {
						tmp_end = (char *) &tmp_end[2];
				}

				/* Reset var options to point to next element */
				if (tmp_end) {
					tmp_end[0] = '\0';
					options = (char *) &tmp_end[1];
				} else
					/* Reached the end of the mount option
					 * string */
					options = end;
			}

			kfree(vol->password);
			/* Now build new password string */
			temp_len = strlen(value);
			vol->password = kzalloc(temp_len+1, GFP_KERNEL);
			if (vol->password == NULL) {
				pr_warn("CIFS: no memory for password\n");
				goto cifs_parse_mount_err;
			}

			for (i = 0, j = 0; i < temp_len; i++, j++) {
				vol->password[j] = value[i];
				if ((value[i] == delim) &&
				     value[i+1] == delim)
					/* skip the second deliminator */
					i++;
			}
			vol->password[j] = '\0';
			break;
		case Opt_blank_ip:
			/* FIXME: should this be an error instead? */
			got_ip = false;
			break;
		case Opt_ip:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (!cifs_convert_address(dstaddr, string,
					strlen(string))) {
				pr_err("CIFS: bad ip= option (%s).\n", string);
				goto cifs_parse_mount_err;
			}
			got_ip = true;
			break;
		case Opt_domain:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (strnlen(string, CIFS_MAX_DOMAINNAME_LEN)
					== CIFS_MAX_DOMAINNAME_LEN) {
				pr_warn("CIFS: domain name too long\n");
				goto cifs_parse_mount_err;
			}

			kfree(vol->domainname);
			vol->domainname = kstrdup(string, GFP_KERNEL);
			if (!vol->domainname) {
				pr_warn("CIFS: no memory for domainname\n");
				goto cifs_parse_mount_err;
			}
			cifs_dbg(FYI, "Domain name set\n");
			break;
		case Opt_srcaddr:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (!cifs_convert_address(
					(struct sockaddr *)&vol->srcaddr,
					string, strlen(string))) {
				pr_warn("CIFS: Could not parse srcaddr: %s\n",
					string);
				goto cifs_parse_mount_err;
			}
			break;
		case Opt_iocharset:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (strnlen(string, 1024) >= 65) {
				pr_warn("CIFS: iocharset name too long.\n");
				goto cifs_parse_mount_err;
			}

			 if (strncasecmp(string, "default", 7) != 0) {
				kfree(vol->iocharset);
				vol->iocharset = kstrdup(string,
							 GFP_KERNEL);
				if (!vol->iocharset) {
					pr_warn("CIFS: no memory for charset\n");
					goto cifs_parse_mount_err;
				}
			}
			/* if iocharset not set then load_nls_default
			 * is used by caller
			 */
			 cifs_dbg(FYI, "iocharset set to %s\n", string);
			break;
		case Opt_netbiosname:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			memset(vol->source_rfc1001_name, 0x20,
				RFC1001_NAME_LEN);
			/*
			 * FIXME: are there cases in which a comma can
			 * be valid in workstation netbios name (and
			 * need special handling)?
			 */
			for (i = 0; i < RFC1001_NAME_LEN; i++) {
				/* don't ucase netbiosname for user */
				if (string[i] == 0)
					break;
				vol->source_rfc1001_name[i] = string[i];
			}
			/* The string has 16th byte zero still from
			 * set at top of the function
			 */
			if (i == RFC1001_NAME_LEN && string[i] != 0)
				pr_warn("CIFS: netbiosname longer than 15 truncated.\n");
			break;
		case Opt_servern:
			/* servernetbiosname specified override *SMBSERVER */
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			/* last byte, type, is 0x20 for servr type */
			memset(vol->target_rfc1001_name, 0x20,
				RFC1001_NAME_LEN_WITH_NULL);

			/* BB are there cases in which a comma can be
			   valid in this workstation netbios name
			   (and need special handling)? */

			/* user or mount helper must uppercase the
			   netbios name */
			for (i = 0; i < 15; i++) {
				if (string[i] == 0)
					break;
				vol->target_rfc1001_name[i] = string[i];
			}
			/* The string has 16th byte zero still from
			   set at top of the function  */
			if (i == RFC1001_NAME_LEN && string[i] != 0)
				pr_warn("CIFS: server netbiosname longer than 15 truncated.\n");
			break;
		case Opt_ver:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (strncasecmp(string, "1", 1) == 0) {
				/* This is the default */
				break;
			}
			/* For all other value, error */
			pr_warn("CIFS: Invalid version specified\n");
			goto cifs_parse_mount_err;
		case Opt_vers:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (cifs_parse_smb_version(string, vol) != 0)
				goto cifs_parse_mount_err;
			break;
		case Opt_sec:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (cifs_parse_security_flavors(string, vol) != 0)
				goto cifs_parse_mount_err;
			break;
		case Opt_cache:
			string = match_strdup(args);
			if (string == NULL)
				goto out_nomem;

			if (cifs_parse_cache_flavor(string, vol) != 0)
				goto cifs_parse_mount_err;
			break;
		default:
			/*
			 * An option we don't recognize. Save it off for later
			 * if we haven't already found one
			 */
			if (!invalid)
				invalid = data;
			break;
		}
		/* Free up any allocated string */
		kfree(string);
		string = NULL;
	}

	if (!sloppy && invalid) {
		pr_err("CIFS: Unknown mount option \"%s\"\n", invalid);
		goto cifs_parse_mount_err;
	}

#ifndef CONFIG_KEYS
	/* Muliuser mounts require CONFIG_KEYS support */
	if (vol->multiuser) {
		cifs_dbg(VFS, "Multiuser mounts require kernels with CONFIG_KEYS enabled\n");
		goto cifs_parse_mount_err;
	}
#endif
	if (!vol->UNC) {
		cifs_dbg(VFS, "CIFS mount error: No usable UNC path provided in device string!\n");
		goto cifs_parse_mount_err;
	}

	/* make sure UNC has a share name */
	if (!strchr(vol->UNC + 3, '\\')) {
		cifs_dbg(VFS, "Malformed UNC. Unable to find share name.\n");
		goto cifs_parse_mount_err;
	}

	if (!got_ip) {
		int len;
		const char *slash;

		/* No ip= option specified? Try to get it from UNC */
		/* Use the address part of the UNC. */
		slash = strchr(&vol->UNC[2], '\\');
		len = slash - &vol->UNC[2];
		if (!cifs_convert_address(dstaddr, &vol->UNC[2], len)) {
			pr_err("Unable to determine destination address.\n");
			goto cifs_parse_mount_err;
		}
	}

	/* set the port that we got earlier */
	cifs_set_port(dstaddr, port);

	if (uid_specified)
		vol->override_uid = override_uid;
	else if (override_uid == 1)
		pr_notice("CIFS: ignoring forceuid mount option specified with no uid= option.\n");

	if (gid_specified)
		vol->override_gid = override_gid;
	else if (override_gid == 1)
		pr_notice("CIFS: ignoring forcegid mount option specified with no gid= option.\n");

	kfree(mountdata_copy);
	return 0;

out_nomem:
	pr_warn("Could not allocate temporary buffer\n");
cifs_parse_mount_err:
	kfree(string);
	kfree(mountdata_copy);
	return 1;
}

/** Returns true if srcaddr isn't specified and rhs isn't
 * specified, or if srcaddr is specified and
 * matches the IP address of the rhs argument.
 */
static bool
srcip_matches(struct sockaddr *srcaddr, struct sockaddr *rhs)
{
	switch (srcaddr->sa_family) {
	case AF_UNSPEC:
		return (rhs->sa_family == AF_UNSPEC);
	case AF_INET: {
		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
	}
	case AF_INET6: {
		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
		return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
	}
	default:
		WARN_ON(1);
		return false; /* don't expect to be here */
	}
}

/*
 * If no port is specified in addr structure, we try to match with 445 port
 * and if it fails - with 139 ports. It should be called only if address
 * families of server and addr are equal.
 */
static bool
match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
{
	__be16 port, *sport;

	switch (addr->sa_family) {
	case AF_INET:
		sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
		port = ((struct sockaddr_in *) addr)->sin_port;
		break;
	case AF_INET6:
		sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
		port = ((struct sockaddr_in6 *) addr)->sin6_port;
		break;
	default:
		WARN_ON(1);
		return false;
	}

	if (!port) {
		port = htons(CIFS_PORT);
		if (port == *sport)
			return true;

		port = htons(RFC1001_PORT);
	}

	return port == *sport;
}

static bool
match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
	      struct sockaddr *srcaddr)
{
	switch (addr->sa_family) {
	case AF_INET: {
		struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
		struct sockaddr_in *srv_addr4 =
					(struct sockaddr_in *)&server->dstaddr;

		if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
			return false;
		break;
	}
	case AF_INET6: {
		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
		struct sockaddr_in6 *srv_addr6 =
					(struct sockaddr_in6 *)&server->dstaddr;

		if (!ipv6_addr_equal(&addr6->sin6_addr,
				     &srv_addr6->sin6_addr))
			return false;
		if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
			return false;
		break;
	}
	default:
		WARN_ON(1);
		return false; /* don't expect to be here */
	}

	if (!srcip_matches(srcaddr, (struct sockaddr *)&server->srcaddr))
		return false;

	return true;
}

static bool
match_security(struct TCP_Server_Info *server, struct smb_vol *vol)
{
	/*
	 * The select_sectype function should either return the vol->sectype
	 * that was specified, or "Unspecified" if that sectype was not
	 * compatible with the given NEGOTIATE request.
	 */
	if (server->ops->select_sectype(server, vol->sectype)
	     == Unspecified)
		return false;

	/*
	 * Now check if signing mode is acceptable. No need to check
	 * global_secflags at this point since if MUST_SIGN is set then
	 * the server->sign had better be too.
	 */
	if (vol->sign && !server->sign)
		return false;

	return true;
}

static int match_server(struct TCP_Server_Info *server, struct smb_vol *vol)
{
	struct sockaddr *addr = (struct sockaddr *)&vol->dstaddr;

	if (vol->nosharesock)
		return 0;

	if ((server->vals != vol->vals) || (server->ops != vol->ops))
		return 0;

	if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
		return 0;

	if (!match_address(server, addr,
			   (struct sockaddr *)&vol->srcaddr))
		return 0;

	if (!match_port(server, addr))
		return 0;

	if (!match_security(server, vol))
		return 0;

	if (server->echo_interval != vol->echo_interval * HZ)
		return 0;

	return 1;
}

static struct TCP_Server_Info *
cifs_find_tcp_session(struct smb_vol *vol)
{
	struct TCP_Server_Info *server;

	spin_lock(&cifs_tcp_ses_lock);
	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
		if (!match_server(server, vol))
			continue;

		++server->srv_count;
		spin_unlock(&cifs_tcp_ses_lock);
		cifs_dbg(FYI, "Existing tcp session with server found\n");
		return server;
	}
	spin_unlock(&cifs_tcp_ses_lock);
	return NULL;
}

void
cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
{
	struct task_struct *task;

	spin_lock(&cifs_tcp_ses_lock);
	if (--server->srv_count > 0) {
		spin_unlock(&cifs_tcp_ses_lock);
		return;
	}

	put_net(cifs_net_ns(server));

	list_del_init(&server->tcp_ses_list);
	spin_unlock(&cifs_tcp_ses_lock);

	cancel_delayed_work_sync(&server->echo);

#ifdef CONFIG_CIFS_SMB2
	if (from_reconnect)
		/*
		 * Avoid deadlock here: reconnect work calls
		 * cifs_put_tcp_session() at its end. Need to be sure
		 * that reconnect work does nothing with server pointer after
		 * that step.
		 */
		cancel_delayed_work(&server->reconnect);
	else
		cancel_delayed_work_sync(&server->reconnect);
#endif

	spin_lock(&GlobalMid_Lock);
	server->tcpStatus = CifsExiting;
	spin_unlock(&GlobalMid_Lock);

	cifs_crypto_secmech_release(server);
	cifs_fscache_release_client_cookie(server);

	kfree(server->session_key.response);
	server->session_key.response = NULL;
	server->session_key.len = 0;

	task = xchg(&server->tsk, NULL);
	if (task)
		force_sig(SIGKILL, task);
}

static struct TCP_Server_Info *
cifs_get_tcp_session(struct smb_vol *volume_info)
{
	struct TCP_Server_Info *tcp_ses = NULL;
	int rc;

	cifs_dbg(FYI, "UNC: %s\n", volume_info->UNC);

	/* see if we already have a matching tcp_ses */
	tcp_ses = cifs_find_tcp_session(volume_info);
	if (tcp_ses)
		return tcp_ses;

	tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
	if (!tcp_ses) {
		rc = -ENOMEM;
		goto out_err;
	}

	tcp_ses->ops = volume_info->ops;
	tcp_ses->vals = volume_info->vals;
	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
	tcp_ses->hostname = extract_hostname(volume_info->UNC);
	if (IS_ERR(tcp_ses->hostname)) {
		rc = PTR_ERR(tcp_ses->hostname);
		goto out_err_crypto_release;
	}

	tcp_ses->noblocksnd = volume_info->noblocksnd;
	tcp_ses->noautotune = volume_info->noautotune;
	tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
	tcp_ses->in_flight = 0;
	tcp_ses->credits = 1;
	init_waitqueue_head(&tcp_ses->response_q);
	init_waitqueue_head(&tcp_ses->request_q);
	INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
	mutex_init(&tcp_ses->srv_mutex);
	memcpy(tcp_ses->workstation_RFC1001_name,
		volume_info->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
	memcpy(tcp_ses->server_RFC1001_name,
		volume_info->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
	tcp_ses->session_estab = false;
	tcp_ses->sequence_number = 0;
	tcp_ses->lstrp = jiffies;
	spin_lock_init(&tcp_ses->req_lock);
	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
#ifdef CONFIG_CIFS_SMB2
	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
	mutex_init(&tcp_ses->reconnect_mutex);
#endif
	memcpy(&tcp_ses->srcaddr, &volume_info->srcaddr,
	       sizeof(tcp_ses->srcaddr));
	memcpy(&tcp_ses->dstaddr, &volume_info->dstaddr,
		sizeof(tcp_ses->dstaddr));
#ifdef CONFIG_CIFS_SMB2
	generate_random_uuid(tcp_ses->client_guid);
#endif
	/*
	 * at this point we are the only ones with the pointer
	 * to the struct since the kernel thread not created yet
	 * no need to spinlock this init of tcpStatus or srv_count
	 */
	tcp_ses->tcpStatus = CifsNew;
	++tcp_ses->srv_count;

	if (volume_info->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
		volume_info->echo_interval <= SMB_ECHO_INTERVAL_MAX)
		tcp_ses->echo_interval = volume_info->echo_interval * HZ;
	else
		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;

	rc = ip_connect(tcp_ses);
	if (rc < 0) {
		cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
		goto out_err_crypto_release;
	}

	/*
	 * since we're in a cifs function already, we know that
	 * this will succeed. No need for try_module_get().
	 */
	__module_get(THIS_MODULE);
	tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
				  tcp_ses, "cifsd");
	if (IS_ERR(tcp_ses->tsk)) {
		rc = PTR_ERR(tcp_ses->tsk);
		cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
		module_put(THIS_MODULE);
		goto out_err_crypto_release;
	}
	tcp_ses->tcpStatus = CifsNeedNegotiate;

	/* thread spawned, put it on the list */
	spin_lock(&cifs_tcp_ses_lock);
	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
	spin_unlock(&cifs_tcp_ses_lock);

	cifs_fscache_get_client_cookie(tcp_ses);

	/* queue echo request delayed work */
	queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);

	return tcp_ses;

out_err_crypto_release:
	cifs_crypto_secmech_release(tcp_ses);

	put_net(cifs_net_ns(tcp_ses));

out_err:
	if (tcp_ses) {
		if (!IS_ERR(tcp_ses->hostname))
			kfree(tcp_ses->hostname);
		if (tcp_ses->ssocket)
			sock_release(tcp_ses->ssocket);
		kfree(tcp_ses);
	}
	return ERR_PTR(rc);
}

static int match_session(struct cifs_ses *ses, struct smb_vol *vol)
{
	if (vol->sectype != Unspecified &&
	    vol->sectype != ses->sectype)
		return 0;

	switch (ses->sectype) {
	case Kerberos:
		if (!uid_eq(vol->cred_uid, ses->cred_uid))
			return 0;
		break;
	default:
		/* NULL username means anonymous session */
		if (ses->user_name == NULL) {
			if (!vol->nullauth)
				return 0;
			break;
		}

		/* anything else takes username/password */
		if (strncmp(ses->user_name,
			    vol->username ? vol->username : "",
			    CIFS_MAX_USERNAME_LEN))
			return 0;
		if ((vol->username && strlen(vol->username) != 0) &&
		    ses->password != NULL &&
		    strncmp(ses->password,
			    vol->password ? vol->password : "",
			    CIFS_MAX_PASSWORD_LEN))
			return 0;
	}
	return 1;
}

static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb_vol *vol)
{
	struct cifs_ses *ses;

	spin_lock(&cifs_tcp_ses_lock);
	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
		if (ses->status == CifsExiting)
			continue;
		if (!match_session(ses, vol))
			continue;
		++ses->ses_count;
		spin_unlock(&cifs_tcp_ses_lock);
		return ses;
	}
	spin_unlock(&cifs_tcp_ses_lock);
	return NULL;
}

static void
cifs_put_smb_ses(struct cifs_ses *ses)
{
	unsigned int rc, xid;
	struct TCP_Server_Info *server = ses->server;

	cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);

	spin_lock(&cifs_tcp_ses_lock);
	if (ses->status == CifsExiting) {
		spin_unlock(&cifs_tcp_ses_lock);
		return;
	}
	if (--ses->ses_count > 0) {
		spin_unlock(&cifs_tcp_ses_lock);
		return;
	}
	if (ses->status == CifsGood)
		ses->status = CifsExiting;
	spin_unlock(&cifs_tcp_ses_lock);

	if (ses->status == CifsExiting && server->ops->logoff) {
		xid = get_xid();
		rc = server->ops->logoff(xid, ses);
		if (rc)
			cifs_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
				__func__, rc);
		_free_xid(xid);
	}

	spin_lock(&cifs_tcp_ses_lock);
	list_del_init(&ses->smb_ses_list);
	spin_unlock(&cifs_tcp_ses_lock);

	sesInfoFree(ses);
	cifs_put_tcp_session(server, 0);
}

#ifdef CONFIG_KEYS

/* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
#define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)

/* Populate username and pw fields from keyring if possible */
static int
cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
{
	int rc = 0;
	const char *delim, *payload;
	char *desc;
	ssize_t len;
	struct key *key;
	struct TCP_Server_Info *server = ses->server;
	struct sockaddr_in *sa;
	struct sockaddr_in6 *sa6;
	const struct user_key_payload *upayload;

	desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
	if (!desc)
		return -ENOMEM;

	/* try to find an address key first */
	switch (server->dstaddr.ss_family) {
	case AF_INET:
		sa = (struct sockaddr_in *)&server->dstaddr;
		sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
		break;
	case AF_INET6:
		sa6 = (struct sockaddr_in6 *)&server->dstaddr;
		sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
		break;
	default:
		cifs_dbg(FYI, "Bad ss_family (%hu)\n",
			 server->dstaddr.ss_family);
		rc = -EINVAL;
		goto out_err;
	}

	cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
	key = request_key(&key_type_logon, desc, "");
	if (IS_ERR(key)) {
		if (!ses->domainName) {
			cifs_dbg(FYI, "domainName is NULL\n");
			rc = PTR_ERR(key);
			goto out_err;
		}

		/* didn't work, try to find a domain key */
		sprintf(desc, "cifs:d:%s", ses->domainName);
		cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
		key = request_key(&key_type_logon, desc, "");
		if (IS_ERR(key)) {
			rc = PTR_ERR(key);
			goto out_err;
		}
	}

	down_read(&key->sem);
	upayload = user_key_payload_locked(key);
	if (IS_ERR_OR_NULL(upayload)) {
		rc = upayload ? PTR_ERR(upayload) : -EINVAL;
		goto out_key_put;
	}

	/* find first : in payload */
	payload = upayload->data;
	delim = strnchr(payload, upayload->datalen, ':');
	cifs_dbg(FYI, "payload=%s\n", payload);
	if (!delim) {
		cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
			 upayload->datalen);
		rc = -EINVAL;
		goto out_key_put;
	}

	len = delim - payload;
	if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
		cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
			 len);
		rc = -EINVAL;
		goto out_key_put;
	}

	vol->username = kstrndup(payload, len, GFP_KERNEL);
	if (!vol->username) {
		cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
			 len);
		rc = -ENOMEM;
		goto out_key_put;
	}
	cifs_dbg(FYI, "%s: username=%s\n", __func__, vol->username);

	len = key->datalen - (len + 1);
	if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
		cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
		rc = -EINVAL;
		kfree(vol->username);
		vol->username = NULL;
		goto out_key_put;
	}

	++delim;
	vol->password = kstrndup(delim, len, GFP_KERNEL);
	if (!vol->password) {
		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
			 len);
		rc = -ENOMEM;
		kfree(vol->username);
		vol->username = NULL;
		goto out_key_put;
	}

out_key_put:
	up_read(&key->sem);
	key_put(key);
out_err:
	kfree(desc);
	cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
	return rc;
}
#else /* ! CONFIG_KEYS */
static inline int
cifs_set_cifscreds(struct smb_vol *vol __attribute__((unused)),
		   struct cifs_ses *ses __attribute__((unused)))
{
	return -ENOSYS;
}
#endif /* CONFIG_KEYS */

static struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info)
{
	int rc = -ENOMEM;
	unsigned int xid;
	struct cifs_ses *ses;
	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;

	xid = get_xid();

	ses = cifs_find_smb_ses(server, volume_info);
	if (ses) {
		cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
			 ses->status);

		mutex_lock(&ses->session_mutex);
		rc = cifs_negotiate_protocol(xid, ses);
		if (rc) {
			mutex_unlock(&ses->session_mutex);
			/* problem -- put our ses reference */
			cifs_put_smb_ses(ses);
			free_xid(xid);
			return ERR_PTR(rc);
		}
		if (ses->need_reconnect) {
			cifs_dbg(FYI, "Session needs reconnect\n");
			rc = cifs_setup_session(xid, ses,
						volume_info->local_nls);
			if (rc) {
				mutex_unlock(&ses->session_mutex);
				/* problem -- put our reference */
				cifs_put_smb_ses(ses);
				free_xid(xid);
				return ERR_PTR(rc);
			}
		}
		mutex_unlock(&ses->session_mutex);

		/* existing SMB ses has a server reference already */
		cifs_put_tcp_session(server, 0);
		free_xid(xid);
		return ses;
	}

	cifs_dbg(FYI, "Existing smb sess not found\n");
	ses = sesInfoAlloc();
	if (ses == NULL)
		goto get_ses_fail;

	/* new SMB session uses our server ref */
	ses->server = server;
	if (server->dstaddr.ss_family == AF_INET6)
		sprintf(ses->serverName, "%pI6", &addr6->sin6_addr);
	else
		sprintf(ses->serverName, "%pI4", &addr->sin_addr);

	if (volume_info->username) {
		ses->user_name = kstrdup(volume_info->username, GFP_KERNEL);
		if (!ses->user_name)
			goto get_ses_fail;
	}

	/* volume_info->password freed at unmount */
	if (volume_info->password) {
		ses->password = kstrdup(volume_info->password, GFP_KERNEL);
		if (!ses->password)
			goto get_ses_fail;
	}
	if (volume_info->domainname) {
		ses->domainName = kstrdup(volume_info->domainname, GFP_KERNEL);
		if (!ses->domainName)
			goto get_ses_fail;
	}
	if (volume_info->domainauto)
		ses->domainAuto = volume_info->domainauto;
	ses->cred_uid = volume_info->cred_uid;
	ses->linux_uid = volume_info->linux_uid;

	ses->sectype = volume_info->sectype;
	ses->sign = volume_info->sign;

	mutex_lock(&ses->session_mutex);
	rc = cifs_negotiate_protocol(xid, ses);
	if (!rc)
		rc = cifs_setup_session(xid, ses, volume_info->local_nls);
	mutex_unlock(&ses->session_mutex);
	if (rc)
		goto get_ses_fail;

	/* success, put it on the list */
	spin_lock(&cifs_tcp_ses_lock);
	list_add(&ses->smb_ses_list, &server->smb_ses_list);
	spin_unlock(&cifs_tcp_ses_lock);

	free_xid(xid);
	return ses;

get_ses_fail:
	sesInfoFree(ses);
	free_xid(xid);
	return ERR_PTR(rc);
}

static int match_tcon(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
	if (tcon->tidStatus == CifsExiting)
		return 0;
	if (strncmp(tcon->treeName, volume_info->UNC, MAX_TREE_SIZE))
		return 0;
	if (tcon->seal != volume_info->seal)
		return 0;
#ifdef CONFIG_CIFS_SMB2
	if (tcon->snapshot_time != volume_info->snapshot_time)
		return 0;
#endif /* CONFIG_CIFS_SMB2 */
	return 1;
}

static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
{
	struct list_head *tmp;
	struct cifs_tcon *tcon;

	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &ses->tcon_list) {
		tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
		if (!match_tcon(tcon, volume_info))
			continue;
		++tcon->tc_count;
		spin_unlock(&cifs_tcp_ses_lock);
		return tcon;
	}
	spin_unlock(&cifs_tcp_ses_lock);
	return NULL;
}

void
cifs_put_tcon(struct cifs_tcon *tcon)
{
	unsigned int xid;
	struct cifs_ses *ses = tcon->ses;

	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
	spin_lock(&cifs_tcp_ses_lock);
	if (--tcon->tc_count > 0) {
		spin_unlock(&cifs_tcp_ses_lock);
		return;
	}

	list_del_init(&tcon->tcon_list);
	spin_unlock(&cifs_tcp_ses_lock);

	xid = get_xid();
	if (ses->server->ops->tree_disconnect)
		ses->server->ops->tree_disconnect(xid, tcon);
	_free_xid(xid);

	cifs_fscache_release_super_cookie(tcon);
	tconInfoFree(tcon);
	cifs_put_smb_ses(ses);
}

static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
{
	int rc, xid;
	struct cifs_tcon *tcon;

	tcon = cifs_find_tcon(ses, volume_info);
	if (tcon) {
		cifs_dbg(FYI, "Found match on UNC path\n");
		/* existing tcon already has a reference */
		cifs_put_smb_ses(ses);
		return tcon;
	}

	if (!ses->server->ops->tree_connect) {
		rc = -ENOSYS;
		goto out_fail;
	}

	tcon = tconInfoAlloc();
	if (tcon == NULL) {
		rc = -ENOMEM;
		goto out_fail;
	}

	if (volume_info->snapshot_time) {
#ifdef CONFIG_CIFS_SMB2
		if (ses->server->vals->protocol_id == 0) {
			cifs_dbg(VFS,
			     "Use SMB2 or later for snapshot mount option\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
		} else
			tcon->snapshot_time = volume_info->snapshot_time;
#else
		cifs_dbg(VFS, "Snapshot mount option requires SMB2 support\n");
		rc = -EOPNOTSUPP;
		goto out_fail;
#endif /* CONFIG_CIFS_SMB2 */
	}

	tcon->ses = ses;
	if (volume_info->password) {
		tcon->password = kstrdup(volume_info->password, GFP_KERNEL);
		if (!tcon->password) {
			rc = -ENOMEM;
			goto out_fail;
		}
	}

	/*
	 * BB Do we need to wrap session_mutex around this TCon call and Unix
	 * SetFS as we do on SessSetup and reconnect?
	 */
	xid = get_xid();
	rc = ses->server->ops->tree_connect(xid, ses, volume_info->UNC, tcon,
					    volume_info->local_nls);
	free_xid(xid);
	cifs_dbg(FYI, "Tcon rc = %d\n", rc);
	if (rc)
		goto out_fail;

	if (volume_info->nodfs) {
		tcon->Flags &= ~SMB_SHARE_IS_IN_DFS;
		cifs_dbg(FYI, "DFS disabled (%d)\n", tcon->Flags);
	}
	tcon->use_persistent = false;
	/* check if SMB2 or later, CIFS does not support persistent handles */
	if (volume_info->persistent) {
		if (ses->server->vals->protocol_id == 0) {
			cifs_dbg(VFS,
			     "SMB3 or later required for persistent handles\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
#ifdef CONFIG_CIFS_SMB2
		} else if (ses->server->capabilities &
			   SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
			tcon->use_persistent = true;
		else /* persistent handles requested but not supported */ {
			cifs_dbg(VFS,
				"Persistent handles not supported on share\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
#endif /* CONFIG_CIFS_SMB2 */
		}
#ifdef CONFIG_CIFS_SMB2
	} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
	     && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
	     && (volume_info->nopersistent == false)) {
		cifs_dbg(FYI, "enabling persistent handles\n");
		tcon->use_persistent = true;
#endif /* CONFIG_CIFS_SMB2 */
	} else if (volume_info->resilient) {
		if (ses->server->vals->protocol_id == 0) {
			cifs_dbg(VFS,
			     "SMB2.1 or later required for resilient handles\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
		}
		tcon->use_resilient = true;
	}

	if (volume_info->seal) {
		if (ses->server->vals->protocol_id == 0) {
			cifs_dbg(VFS,
				 "SMB3 or later required for encryption\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
#ifdef CONFIG_CIFS_SMB2
		} else if (tcon->ses->server->capabilities &
					SMB2_GLOBAL_CAP_ENCRYPTION)
			tcon->seal = true;
		else {
			cifs_dbg(VFS, "Encryption is not supported on share\n");
			rc = -EOPNOTSUPP;
			goto out_fail;
#endif /* CONFIG_CIFS_SMB2 */
		}
	}

	/*
	 * We can have only one retry value for a connection to a share so for
	 * resources mounted more than once to the same server share the last
	 * value passed in for the retry flag is used.
	 */
	tcon->retry = volume_info->retry;
	tcon->nocase = volume_info->nocase;
	tcon->local_lease = volume_info->local_lease;
	INIT_LIST_HEAD(&tcon->pending_opens);

	spin_lock(&cifs_tcp_ses_lock);
	list_add(&tcon->tcon_list, &ses->tcon_list);
	spin_unlock(&cifs_tcp_ses_lock);

	cifs_fscache_get_super_cookie(tcon);

	return tcon;

out_fail:
	tconInfoFree(tcon);
	return ERR_PTR(rc);
}

void
cifs_put_tlink(struct tcon_link *tlink)
{
	if (!tlink || IS_ERR(tlink))
		return;

	if (!atomic_dec_and_test(&tlink->tl_count) ||
	    test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
		tlink->tl_time = jiffies;
		return;
	}

	if (!IS_ERR(tlink_tcon(tlink)))
		cifs_put_tcon(tlink_tcon(tlink));
	kfree(tlink);
	return;
}

static inline struct tcon_link *
cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb)
{
	return cifs_sb->master_tlink;
}

static int
compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
	struct cifs_sb_info *old = CIFS_SB(sb);
	struct cifs_sb_info *new = mnt_data->cifs_sb;

	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
		return 0;

	if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) !=
	    (new->mnt_cifs_flags & CIFS_MOUNT_MASK))
		return 0;

	/*
	 * We want to share sb only if we don't specify an r/wsize or
	 * specified r/wsize is greater than or equal to existing one.
	 */
	if (new->wsize && new->wsize < old->wsize)
		return 0;

	if (new->rsize && new->rsize < old->rsize)
		return 0;

	if (!uid_eq(old->mnt_uid, new->mnt_uid) || !gid_eq(old->mnt_gid, new->mnt_gid))
		return 0;

	if (old->mnt_file_mode != new->mnt_file_mode ||
	    old->mnt_dir_mode != new->mnt_dir_mode)
		return 0;

	if (strcmp(old->local_nls->charset, new->local_nls->charset))
		return 0;

	if (old->actimeo != new->actimeo)
		return 0;

	return 1;
}

static int
match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
	struct cifs_sb_info *old = CIFS_SB(sb);
	struct cifs_sb_info *new = mnt_data->cifs_sb;
	bool old_set = old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH;
	bool new_set = new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH;

	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
		return 1;
	else if (!old_set && !new_set)
		return 1;

	return 0;
}

int
cifs_match_super(struct super_block *sb, void *data)
{
	struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
	struct smb_vol *volume_info;
	struct cifs_sb_info *cifs_sb;
	struct TCP_Server_Info *tcp_srv;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct tcon_link *tlink;
	int rc = 0;

	spin_lock(&cifs_tcp_ses_lock);
	cifs_sb = CIFS_SB(sb);
	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
	if (IS_ERR(tlink)) {
		spin_unlock(&cifs_tcp_ses_lock);
		return rc;
	}
	tcon = tlink_tcon(tlink);
	ses = tcon->ses;
	tcp_srv = ses->server;

	volume_info = mnt_data->vol;

	if (!match_server(tcp_srv, volume_info) ||
	    !match_session(ses, volume_info) ||
	    !match_tcon(tcon, volume_info) ||
	    !match_prepath(sb, mnt_data)) {
		rc = 0;
		goto out;
	}

	rc = compare_mount_options(sb, mnt_data);
out:
	spin_unlock(&cifs_tcp_ses_lock);
	cifs_put_tlink(tlink);
	return rc;
}

int
get_dfs_path(const unsigned int xid, struct cifs_ses *ses, const char *old_path,
	     const struct nls_table *nls_codepage, unsigned int *num_referrals,
	     struct dfs_info3_param **referrals, int remap)
{
	char *temp_unc;
	int rc = 0;

	if (!ses->server->ops->tree_connect || !ses->server->ops->get_dfs_refer)
		return -ENOSYS;

	*num_referrals = 0;
	*referrals = NULL;

	if (ses->ipc_tid == 0) {
		temp_unc = kmalloc(2 /* for slashes */ +
			strnlen(ses->serverName, SERVER_NAME_LEN_WITH_NULL * 2)
				+ 1 + 4 /* slash IPC$ */ + 2, GFP_KERNEL);
		if (temp_unc == NULL)
			return -ENOMEM;
		temp_unc[0] = '\\';
		temp_unc[1] = '\\';
		strcpy(temp_unc + 2, ses->serverName);
		strcpy(temp_unc + 2 + strlen(ses->serverName), "\\IPC$");
		rc = ses->server->ops->tree_connect(xid, ses, temp_unc, NULL,
						    nls_codepage);
		cifs_dbg(FYI, "Tcon rc = %d ipc_tid = %d\n", rc, ses->ipc_tid);
		kfree(temp_unc);
	}
	if (rc == 0)
		rc = ses->server->ops->get_dfs_refer(xid, ses, old_path,
						     referrals, num_referrals,
						     nls_codepage, remap);
	/*
	 * BB - map targetUNCs to dfs_info3 structures, here or in
	 * ses->server->ops->get_dfs_refer.
	 */

	return rc;
}

#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key cifs_key[2];
static struct lock_class_key cifs_slock_key[2];

static inline void
cifs_reclassify_socket4(struct socket *sock)
{
	struct sock *sk = sock->sk;
	BUG_ON(!sock_allow_reclassification(sk));
	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
}

static inline void
cifs_reclassify_socket6(struct socket *sock)
{
	struct sock *sk = sock->sk;
	BUG_ON(!sock_allow_reclassification(sk));
	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
}
#else
static inline void
cifs_reclassify_socket4(struct socket *sock)
{
}

static inline void
cifs_reclassify_socket6(struct socket *sock