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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: LGPL-2.1
 /*
  *
  *   Copyright (C) International Business Machines  Corp., 2002,2011
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *
  */
 #include <linux/fs.h>
 #include <linux/net.h>
 #include <linux/string.h>
 #include <linux/sched/mm.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"
 #include "smb2proto.h"
 #include "smbdirect.h"
 #include "dns_resolve.h"
 #ifdef CONFIG_CIFS_DFS_UPCALL
 #include "dfs_cache.h"
 #endif
 #include "fs_context.h"
 #include "cifs_swn.h"
 
 extern mempool_t *cifs_req_poolp;
 extern bool disable_legacy_dialects;
 
 /* FIXME: should these be tunable? */
 #define TLINK_ERROR_EXPIRE  (1 * HZ)
 #define TLINK_IDLE_EXPIRE   (600 * HZ)
 
 /* Drop the connection to not overload the server */
 #define NUM_STATUS_IO_TIMEOUT   5
 
 struct mount_ctx {
     struct cifs_sb_info *cifs_sb;
     struct smb3_fs_context *fs_ctx;
     unsigned int xid;
     struct TCP_Server_Info *server;
     struct cifs_ses *ses;
     struct cifs_tcon *tcon;
 #ifdef CONFIG_CIFS_DFS_UPCALL
     struct cifs_ses *root_ses;
     uuid_t mount_id;
     char *origin_fullpath, *leaf_fullpath;
 #endif
 };
 
 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);
 
 /*
  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  * get their ip addresses changed at some point.
  *
  * This should be called with server->srv_mutex held.
  */
 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 {
     int rc;
     int len;
     char *unc, *ipaddr = NULL;
     time64_t expiry, now;
     unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
 
     if (!server->hostname)
         return -EINVAL;
 
     /* if server hostname isn't populated, there's nothing to do here */
     if (server->hostname[0] == '\0')
         return 0;
 
     len = strlen(server->hostname) + 3;
 
     unc = kmalloc(len, GFP_KERNEL);
     if (!unc) {
         cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
         return -ENOMEM;
     }
     scnprintf(unc, len, "\\\\%s", server->hostname);
 
     rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
     kfree(unc);
 
     if (rc < 0) {
         cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
              __func__, server->hostname, rc);
         goto requeue_resolve;
     }
 
     spin_lock(&server->srv_lock);
     rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
                   strlen(ipaddr));
     spin_unlock(&server->srv_lock);
     kfree(ipaddr);
 
     /* rc == 1 means success here */
     if (rc) {
         now = ktime_get_real_seconds();
         if (expiry && expiry > now)
             /*
              * To make sure we don't use the cached entry, retry 1s
              * after expiry.
              */
             ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
     }
     rc = !rc ? -1 : 0;
 
 requeue_resolve:
     cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
          __func__, ttl);
     mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 
     return rc;
 }
 
 static void smb2_query_server_interfaces(struct work_struct *work)
 {
     int rc;
     struct cifs_tcon *tcon = container_of(work,
                     struct cifs_tcon,
                     query_interfaces.work);
 
     /*
      * query server network interfaces, in case they change
      */
     rc = SMB3_request_interfaces(0, tcon);
     if (rc) {
         cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
                 __func__, rc);
     }
 
     queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
                (SMB_INTERFACE_POLL_INTERVAL * HZ));
 }
 
 static void cifs_resolve_server(struct work_struct *work)
 {
     int rc;
     struct TCP_Server_Info *server = container_of(work,
                     struct TCP_Server_Info, resolve.work);
 
     cifs_server_lock(server);
 
     /*
      * Resolve the hostname again to make sure that IP address is up-to-date.
      */
     rc = reconn_set_ipaddr_from_hostname(server);
     if (rc) {
         cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
                 __func__, rc);
     }
 
     cifs_server_unlock(server);
 }
 
 /*
  * Update the tcpStatus for the server.
  * This is used to signal the cifsd thread to call cifs_reconnect
  * ONLY cifsd thread should call cifs_reconnect. For any other
  * thread, use this function
  *
  * @server: the tcp ses for which reconnect is needed
  * @all_channels: if this needs to be done for all channels
  */
 void
 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
                 bool all_channels)
 {
     struct TCP_Server_Info *pserver;
     struct cifs_ses *ses;
     int i;
 
     /* If server is a channel, select the primary channel */
     pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 
     spin_lock(&pserver->srv_lock);
     if (!all_channels) {
         pserver->tcpStatus = CifsNeedReconnect;
         spin_unlock(&pserver->srv_lock);
         return;
     }
     spin_unlock(&pserver->srv_lock);
 
     spin_lock(&cifs_tcp_ses_lock);
     list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
         spin_lock(&ses->chan_lock);
         for (i = 0; i < ses->chan_count; i++) {
             spin_lock(&ses->chans[i].server->srv_lock);
             ses->chans[i].server->tcpStatus = CifsNeedReconnect;
             spin_unlock(&ses->chans[i].server->srv_lock);
         }
         spin_unlock(&ses->chan_lock);
     }
     spin_unlock(&cifs_tcp_ses_lock);
 }
 
 /*
  * Mark all sessions and tcons for reconnect.
  * IMPORTANT: make sure that this gets called only from
  * cifsd thread. For any other thread, use
  * cifs_signal_cifsd_for_reconnect
  *
  * @server: the tcp ses for which reconnect is needed
  * @server needs to be previously set to CifsNeedReconnect.
  * @mark_smb_session: whether even sessions need to be marked
  */
 void
 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
                       bool mark_smb_session)
 {
     struct TCP_Server_Info *pserver;
     struct cifs_ses *ses, *nses;
     struct cifs_tcon *tcon;
 
     /*
      * 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 necessary sessions and tcons for reconnect\n", __func__);
 
     /* If server is a channel, select the primary channel */
     pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 
 
     spin_lock(&cifs_tcp_ses_lock);
     list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
         /* check if iface is still active */
         if (!cifs_chan_is_iface_active(ses, server))
             cifs_chan_update_iface(ses, server);
 
         spin_lock(&ses->chan_lock);
         if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
             goto next_session;
 
         if (mark_smb_session)
             CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
         else
             cifs_chan_set_need_reconnect(ses, server);
 
         /* If all channels need reconnect, then tcon needs reconnect */
         if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
             goto next_session;
 
         ses->ses_status = SES_NEED_RECON;
 
         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
             tcon->need_reconnect = true;
             tcon->status = TID_NEED_RECON;
         }
         if (ses->tcon_ipc)
             ses->tcon_ipc->need_reconnect = true;
 
 next_session:
         spin_unlock(&ses->chan_lock);
     }
     spin_unlock(&cifs_tcp_ses_lock);
 }
 
 static void
 cifs_abort_connection(struct TCP_Server_Info *server)
 {
     struct mid_q_entry *mid, *nmid;
     struct list_head retry_list;
 
     server->maxBuf = 0;
     server->max_read = 0;
 
     /* do not want to be sending data on a socket we are freeing */
     cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
     cifs_server_lock(server);
     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(&server->mid_lock);
     list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
         kref_get(&mid->refcount);
         if (mid->mid_state == MID_REQUEST_SUBMITTED)
             mid->mid_state = MID_RETRY_NEEDED;
         list_move(&mid->qhead, &retry_list);
         mid->mid_flags |= MID_DELETED;
     }
     spin_unlock(&server->mid_lock);
     cifs_server_unlock(server);
 
     cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
     list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
         list_del_init(&mid->qhead);
         mid->callback(mid);
         release_mid(mid);
     }
 
     if (cifs_rdma_enabled(server)) {
         cifs_server_lock(server);
         smbd_destroy(server);
         cifs_server_unlock(server);
     }
 }
 
 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 {
     spin_lock(&server->srv_lock);
     server->nr_targets = num_targets;
     if (server->tcpStatus == CifsExiting) {
         /* the demux thread will exit normally next time through the loop */
         spin_unlock(&server->srv_lock);
         wake_up(&server->response_q);
         return false;
     }
 
     cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
     trace_smb3_reconnect(server->CurrentMid, server->conn_id,
                  server->hostname);
     server->tcpStatus = CifsNeedReconnect;
 
     spin_unlock(&server->srv_lock);
     return true;
 }
 
 /*
  * 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)
  *
  * if mark_smb_session is passed as true, unconditionally mark
  * the smb session (and tcon) for reconnect as well. This value
  * doesn't really matter for non-multichannel scenario.
  *
  */
 static int __cifs_reconnect(struct TCP_Server_Info *server,
                 bool mark_smb_session)
 {
     int rc = 0;
 
     if (!cifs_tcp_ses_needs_reconnect(server, 1))
         return 0;
 
     cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 
     cifs_abort_connection(server);
 
     do {
         try_to_freeze();
         cifs_server_lock(server);
 
         if (!cifs_swn_set_server_dstaddr(server)) {
             /* resolve the hostname again to make sure that IP address is up-to-date */
             rc = reconn_set_ipaddr_from_hostname(server);
             cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
         }
 
         if (cifs_rdma_enabled(server))
             rc = smbd_reconnect(server);
         else
             rc = generic_ip_connect(server);
         if (rc) {
             cifs_server_unlock(server);
             cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
             msleep(3000);
         } else {
             atomic_inc(&tcpSesReconnectCount);
             set_credits(server, 1);
             spin_lock(&server->srv_lock);
             if (server->tcpStatus != CifsExiting)
                 server->tcpStatus = CifsNeedNegotiate;
             spin_unlock(&server->srv_lock);
             cifs_swn_reset_server_dstaddr(server);
             cifs_server_unlock(server);
             mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
         }
     } while (server->tcpStatus == CifsNeedReconnect);
 
     spin_lock(&server->srv_lock);
     if (server->tcpStatus == CifsNeedNegotiate)
         mod_delayed_work(cifsiod_wq, &server->echo, 0);
     spin_unlock(&server->srv_lock);
 
     wake_up(&server->response_q);
     return rc;
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 {
     int rc;
     char *hostname;
 
     if (!cifs_swn_set_server_dstaddr(server)) {
         if (server->hostname != target) {
             hostname = extract_hostname(target);
             if (!IS_ERR(hostname)) {
                 kfree(server->hostname);
                 server->hostname = hostname;
             } else {
                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
                      __func__, PTR_ERR(hostname));
                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
                      server->hostname);
             }
         }
         /* resolve the hostname again to make sure that IP address is up-to-date. */
         rc = reconn_set_ipaddr_from_hostname(server);
         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
     }
     /* Reconnect the socket */
     if (cifs_rdma_enabled(server))
         rc = smbd_reconnect(server);
     else
         rc = generic_ip_connect(server);
 
     return rc;
 }
 
 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
                      struct dfs_cache_tgt_iterator **target_hint)
 {
     int rc;
     struct dfs_cache_tgt_iterator *tit;
 
     *target_hint = NULL;
 
     /* If dfs target list is empty, then reconnect to last server */
     tit = dfs_cache_get_tgt_iterator(tl);
     if (!tit)
         return __reconnect_target_unlocked(server, server->hostname);
 
     /* Otherwise, try every dfs target in @tl */
     for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
         rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
         if (!rc) {
             *target_hint = tit;
             break;
         }
     }
     return rc;
 }
 
 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 {
     int rc = 0;
     const char *refpath = server->current_fullpath + 1;
     struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
     struct dfs_cache_tgt_iterator *target_hint = NULL;
     int num_targets = 0;
 
     /*
      * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
      *
      * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
      * targets (server->nr_targets).  It's also possible that the cached referral was cleared
      * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
      * refreshing the referral, so, in this case, default it to 1.
      */
     if (!dfs_cache_noreq_find(refpath, NULL, &tl))
         num_targets = dfs_cache_get_nr_tgts(&tl);
     if (!num_targets)
         num_targets = 1;
 
     if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
         return 0;
 
     /*
      * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
      * different server or share during failover.  It could be improved by adding some logic to
      * only do that in case it connects to a different server or share, though.
      */
     cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 
     cifs_abort_connection(server);
 
     do {
         try_to_freeze();
         cifs_server_lock(server);
 
         rc = reconnect_target_unlocked(server, &tl, &target_hint);
         if (rc) {
             /* Failed to reconnect socket */
             cifs_server_unlock(server);
             cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
             msleep(3000);
             continue;
         }
         /*
          * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
          * process waiting for reconnect will know it needs to re-establish session and tcon
          * through the reconnected target server.
          */
         atomic_inc(&tcpSesReconnectCount);
         set_credits(server, 1);
         spin_lock(&server->srv_lock);
         if (server->tcpStatus != CifsExiting)
             server->tcpStatus = CifsNeedNegotiate;
         spin_unlock(&server->srv_lock);
         cifs_swn_reset_server_dstaddr(server);
         cifs_server_unlock(server);
         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
     } while (server->tcpStatus == CifsNeedReconnect);
 
     if (target_hint)
         dfs_cache_noreq_update_tgthint(refpath, target_hint);
 
     dfs_cache_free_tgts(&tl);
 
     /* Need to set up echo worker again once connection has been established */
     spin_lock(&server->srv_lock);
     if (server->tcpStatus == CifsNeedNegotiate)
         mod_delayed_work(cifsiod_wq, &server->echo, 0);
     spin_unlock(&server->srv_lock);
 
     wake_up(&server->response_q);
     return rc;
 }
 
 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 {
     /* If tcp session is not an dfs connection, then reconnect to last target server */
     spin_lock(&server->srv_lock);
     if (!server->is_dfs_conn) {
         spin_unlock(&server->srv_lock);
         return __cifs_reconnect(server, mark_smb_session);
     }
     spin_unlock(&server->srv_lock);
 
     mutex_lock(&server->refpath_lock);
     if (!server->origin_fullpath || !server->leaf_fullpath) {
         mutex_unlock(&server->refpath_lock);
         return __cifs_reconnect(server, mark_smb_session);
     }
     mutex_unlock(&server->refpath_lock);
 
     return reconnect_dfs_server(server);
 }
 #else
 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 {
     return __cifs_reconnect(server, mark_smb_session);
 }
 #endif
 
 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);
 
     /*
      * 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 + server->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);
 
     /* Check witness registrations */
     cifs_swn_check();
 
 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_server_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_server_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 3 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.
      */
     spin_lock(&server->srv_lock);
     if ((server->tcpStatus == CifsGood ||
         server->tcpStatus == CifsNeedNegotiate) &&
         (!server->ops->can_echo || server->ops->can_echo(server)) &&
         time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
         spin_unlock(&server->srv_lock);
         cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
              (3 * server->echo_interval) / HZ);
         cifs_reconnect(server, false);
         return true;
     }
     spin_unlock(&server->srv_lock);
 
     return false;
 }
 
 static inline bool
 zero_credits(struct TCP_Server_Info *server)
 {
     int val;
 
     spin_lock(&server->req_lock);
     val = server->credits + server->echo_credits + server->oplock_credits;
     if (server->in_flight == 0 && val == 0) {
         spin_unlock(&server->req_lock);
         return true;
     }
     spin_unlock(&server->req_lock);
     return false;
 }
 
 static int
 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
     int length = 0;
     int total_read;
 
     for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
         try_to_freeze();
 
         /* reconnect if no credits and no requests in flight */
         if (zero_credits(server)) {
             cifs_reconnect(server, false);
             return -ECONNABORTED;
         }
 
         if (server_unresponsive(server))
             return -ECONNABORTED;
         if (cifs_rdma_enabled(server) && server->smbd_conn)
             length = smbd_recv(server->smbd_conn, smb_msg);
         else
             length = sock_recvmsg(server->ssocket, smb_msg, 0);
 
         spin_lock(&server->srv_lock);
         if (server->tcpStatus == CifsExiting) {
             spin_unlock(&server->srv_lock);
             return -ESHUTDOWN;
         }
 
         if (server->tcpStatus == CifsNeedReconnect) {
             spin_unlock(&server->srv_lock);
             cifs_reconnect(server, false);
             return -ECONNABORTED;
         }
         spin_unlock(&server->srv_lock);
 
         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, false);
             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, &iov, 1, to_read);
 
     return cifs_readv_from_socket(server, &smb_msg);
 }
 
 ssize_t
 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 {
     struct msghdr smb_msg = {};
 
     /*
      *  iov_iter_discard already sets smb_msg.type and count and iov_offset
      *  and cifs_readv_from_socket sets msg_control and msg_controllen
      *  so little to initialize in struct msghdr
      */
     iov_iter_discard(&smb_msg.msg_iter, READ, 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 page_offset, unsigned int to_read)
 {
     struct msghdr smb_msg = {};
     struct bio_vec bv = {
         .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
     iov_iter_bvec(&smb_msg.msg_iter, READ, &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, true);
         break;
     default:
         cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
         cifs_reconnect(server, true);
     }
 
     return false;
 }
 
 void
 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 {
 #ifdef CONFIG_CIFS_STATS2
     mid->when_received = jiffies;
 #endif
     spin_lock(&mid->server->mid_lock);
     if (!malformed)
         mid->mid_state = MID_RESPONSE_RECEIVED;
     else
         mid->mid_state = MID_RESPONSE_MALFORMED;
     /*
      * Trying to handle/dequeue a mid after the send_recv()
      * function has finished processing it is a bug.
      */
     if (mid->mid_flags & MID_DELETED) {
         spin_unlock(&mid->server->mid_lock);
         pr_warn_once("trying to dequeue a deleted mid\n");
     } else {
         list_del_init(&mid->qhead);
         mid->mid_flags |= MID_DELETED;
         spin_unlock(&mid->server->mid_lock);
     }
 }
 
 static unsigned int
 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 {
     struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 
     /*
      * SMB1 does not use credits.
      */
     if (is_smb1(server))
         return 0;
 
     return le16_to_cpu(shdr->CreditRequest);
 }
 
 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->credits_received = smb2_get_credits_from_hdr(buf, server);
     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);
 }
 
 int
 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 {
     bool srv_sign_required = server->sec_mode & server->vals->signing_required;
     bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
     bool mnt_sign_enabled;
 
     /*
      * Is signing required by mnt options? If not then check
      * global_secflags to see if it is there.
      */
     if (!mnt_sign_required)
         mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
                         CIFSSEC_MUST_SIGN);
 
     /*
      * If signing is required then it's automatically enabled too,
      * otherwise, check to see if the secflags allow it.
      */
     mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
                 (global_secflags & CIFSSEC_MAY_SIGN);
 
     /* If server requires signing, does client allow it? */
     if (srv_sign_required) {
         if (!mnt_sign_enabled) {
             cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
             return -EOPNOTSUPP;
         }
         server->sign = true;
     }
 
     /* If client requires signing, does server allow it? */
     if (mnt_sign_required) {
         if (!srv_sign_enabled) {
             cifs_dbg(VFS, "Server does not support signing!\n");
             return -EOPNOTSUPP;
         }
         server->sign = true;
     }
 
     if (cifs_rdma_enabled(server) && server->sign)
         cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 
     return 0;
 }
 
 
 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 {
     int length;
 
     /* take it off the list, if it's not already */
     spin_lock(&server->srv_lock);
     list_del_init(&server->tcp_ses_list);
     spin_unlock(&server->srv_lock);
 
     cancel_delayed_work_sync(&server->echo);
     cancel_delayed_work_sync(&server->resolve);
 
     spin_lock(&server->srv_lock);
     server->tcpStatus = CifsExiting;
     spin_unlock(&server->srv_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 (cifs_rdma_enabled(server))
         smbd_destroy(server);
     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(&server->mid_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 %llu\n", mid_entry->mid);
             kref_get(&mid_entry->refcount);
             mid_entry->mid_state = MID_SHUTDOWN;
             list_move(&mid_entry->qhead, &dispose_list);
             mid_entry->mid_flags |= MID_DELETED;
         }
         spin_unlock(&server->mid_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 %llu\n", mid_entry->mid);
             list_del_init(&mid_entry->qhead);
             mid_entry->callback(mid_entry);
             release_mid(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.
          */
     }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
     kfree(server->origin_fullpath);
     kfree(server->leaf_fullpath);
 #endif
     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 = server->pdu_size;
 
     /* make sure this will fit in a large buffer */
     if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
         HEADER_PREAMBLE_SIZE(server)) {
         cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
         cifs_reconnect(server, true);
         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 - MID_HEADER_SIZE(server));
 
     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 rc;
 
     /*
      * 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.
      *
      * 48 bytes is enough to display the header and a little bit
      * into the payload for debugging purposes.
      */
     rc = server->ops->check_message(buf, server->total_read, server);
     if (rc)
         cifs_dump_mem("Bad SMB: ", buf,
             min_t(unsigned int, server->total_read, 48));
 
     if (server->ops->is_session_expired &&
         server->ops->is_session_expired(buf)) {
         cifs_reconnect(server, true);
         return -1;
     }
 
     if (server->ops->is_status_pending &&
         server->ops->is_status_pending(buf, server))
         return -1;
 
     if (!mid)
         return rc;
 
     handle_mid(mid, server, buf, rc);
     return 0;
 }
 
 static void
 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 {
     struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
     int scredits, in_flight;
 
     /*
      * SMB1 does not use credits.
      */
     if (is_smb1(server))
         return;
 
     if (shdr->CreditRequest) {
         spin_lock(&server->req_lock);
         server->credits += le16_to_cpu(shdr->CreditRequest);
         scredits = server->credits;
         in_flight = server->in_flight;
         spin_unlock(&server->req_lock);
         wake_up(&server->request_q);
 
         trace_smb3_hdr_credits(server->CurrentMid,
                 server->conn_id, server->hostname, scredits,
                 le16_to_cpu(shdr->CreditRequest), in_flight);
         cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
                 __func__, le16_to_cpu(shdr->CreditRequest),
                 scredits);
     }
 }
 
 
 static int
 cifs_demultiplex_thread(void *p)
 {
     int i, num_mids, length;
     struct TCP_Server_Info *server = p;
     unsigned int pdu_length;
     unsigned int next_offset;
     char *buf = NULL;
     struct task_struct *task_to_wake = NULL;
     struct mid_q_entry *mids[MAX_COMPOUND];
     char *bufs[MAX_COMPOUND];
     unsigned int noreclaim_flag, num_io_timeout = 0;
 
     noreclaim_flag = memalloc_noreclaim_save();
     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();
     allow_kernel_signal(SIGKILL);
     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;
 
         if (is_smb1(server))
             server->total_read = length;
         else
             server->total_read = 0;
 
         /*
          * 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;
 next_pdu:
         server->pdu_size = pdu_length;
 
         /* make sure we have enough to get to the MID */
         if (server->pdu_size < MID_HEADER_SIZE(server)) {
             cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
                  server->pdu_size);
             cifs_reconnect(server, true);
             continue;
         }
 
         /* read down to the MID */
         length = cifs_read_from_socket(server,
                  buf + HEADER_PREAMBLE_SIZE(server),
                  MID_HEADER_SIZE(server));
         if (length < 0)
             continue;
         server->total_read += length;
 
         if (server->ops->next_header) {
             next_offset = server->ops->next_header(buf);
             if (next_offset)
                 server->pdu_size = next_offset;
         }
 
         memset(mids, 0, sizeof(mids));
         memset(bufs, 0, sizeof(bufs));
         num_mids = 0;
 
         if (server->ops->is_transform_hdr &&
             server->ops->receive_transform &&
             server->ops->is_transform_hdr(buf)) {
             length = server->ops->receive_transform(server,
                                 mids,
                                 bufs,
                                 &num_mids);
         } else {
             mids[0] = server->ops->find_mid(server, buf);
             bufs[0] = buf;
             num_mids = 1;
 
             if (!mids[0] || !mids[0]->receive)
                 length = standard_receive3(server, mids[0]);
             else
                 length = mids[0]->receive(server, mids[0]);
         }
 
         if (length < 0) {
             for (i = 0; i < num_mids; i++)
                 if (mids[i])
                     release_mid(mids[i]);
             continue;
         }
 
         if (server->ops->is_status_io_timeout &&
             server->ops->is_status_io_timeout(buf)) {
             num_io_timeout++;
             if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
                 cifs_reconnect(server, false);
                 num_io_timeout = 0;
                 continue;
             }
         }
 
         server->lstrp = jiffies;
 
         for (i = 0; i < num_mids; i++) {
             if (mids[i] != NULL) {
                 mids[i]->resp_buf_size = server->pdu_size;
 
                 if (bufs[i] && server->ops->is_network_name_deleted)
                     server->ops->is_network_name_deleted(bufs[i],
                                     server);
 
                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
                     mids[i]->callback(mids[i]);
 
                 release_mid(mids[i]);
             } else if (server->ops->is_oplock_break &&
                    server->ops->is_oplock_break(bufs[i],
                                 server)) {
                 smb2_add_credits_from_hdr(bufs[i], server);
                 cifs_dbg(FYI, "Received oplock break\n");
             } else {
                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
                         atomic_read(&mid_count));
                 cifs_dump_mem("Received Data is: ", bufs[i],
                           HEADER_SIZE(server));
                 smb2_add_credits_from_hdr(bufs[i], server);
 #ifdef CONFIG_CIFS_DEBUG2
                 if (server->ops->dump_detail)
                     server->ops->dump_detail(bufs[i],
                                  server);
                 cifs_dump_mids(server);
 #endif /* CIFS_DEBUG2 */
             }
         }
 
         if (pdu_length > server->pdu_size) {
             if (!allocate_buffers(server))
                 continue;
             pdu_length -= server->pdu_size;
             server->total_read = 0;
             server->large_buf = false;
             buf = server->smallbuf;
             goto next_pdu;
         }
     } /* 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);
     }
 
     memalloc_noreclaim_restore(noreclaim_flag);
     module_put_and_kthread_exit(0);
 }
 
 /*
  * 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
  */
 bool
 cifs_match_ipaddr(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;
 
     /* SMBDirect manages its own ports, don't match it here */
     if (server->rdma)
         return true;
 
     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 (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
         return false;
 
     return true;
 }
 
 static bool
 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
     /*
      * The select_sectype function should either return the ctx->sectype
      * that was specified, or "Unspecified" if that sectype was not
      * compatible with the given NEGOTIATE request.
      */
     if (server->ops->select_sectype(server, ctx->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 (ctx->sign && !server->sign)
         return false;
 
     return true;
 }
 
 /* this function must be called with srv_lock held */
 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
     struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
 
     if (ctx->nosharesock)
         return 0;
 
     /* this server does not share socket */
     if (server->nosharesock)
         return 0;
 
     /* If multidialect negotiation see if existing sessions match one */
     if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
         if (server->vals->protocol_id < SMB30_PROT_ID)
             return 0;
     } else if (strcmp(ctx->vals->version_string,
            SMBDEFAULT_VERSION_STRING) == 0) {
         if (server->vals->protocol_id < SMB21_PROT_ID)
             return 0;
     } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
         return 0;
 
     if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
         return 0;
 
     if (strcasecmp(server->hostname, ctx->server_hostname))
         return 0;
 
     if (!match_address(server, addr,
                (struct sockaddr *)&ctx->srcaddr))
         return 0;
 
     if (!match_port(server, addr))
         return 0;
 
     if (!match_security(server, ctx))
         return 0;
 
     if (server->echo_interval != ctx->echo_interval * HZ)
         return 0;
 
     if (server->rdma != ctx->rdma)
         return 0;
 
     if (server->ignore_signature != ctx->ignore_signature)
         return 0;
 
     if (server->min_offload != ctx->min_offload)
         return 0;
 
     return 1;
 }
 
 struct TCP_Server_Info *
 cifs_find_tcp_session(struct smb3_fs_context *ctx)
 {
     struct TCP_Server_Info *server;
 
     spin_lock(&cifs_tcp_ses_lock);
     list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
         spin_lock(&server->srv_lock);
 #ifdef CONFIG_CIFS_DFS_UPCALL
         /*
          * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
          * DFS connections to do failover properly, so avoid sharing them with regular
          * shares or even links that may connect to same server but having completely
          * different failover targets.
          */
         if (server->is_dfs_conn) {
             spin_unlock(&server->srv_lock);
             continue;
         }
 #endif
         /*
          * Skip ses channels since they're only handled in lower layers
          * (e.g. cifs_send_recv).
          */
         if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
             spin_unlock(&server->srv_lock);
             continue;
         }
         spin_unlock(&server->srv_lock);
 
         ++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;
     }
 
     /* srv_count can never go negative */
     WARN_ON(server->srv_count < 0);
 
     put_net(cifs_net_ns(server));
 
     list_del_init(&server->tcp_ses_list);
     spin_unlock(&cifs_tcp_ses_lock);
 
     /* For secondary channels, we pick up ref-count on the primary server */
     if (CIFS_SERVER_IS_CHAN(server))
         cifs_put_tcp_session(server->primary_server, from_reconnect);
 
     cancel_delayed_work_sync(&server->echo);
     cancel_delayed_work_sync(&server->resolve);
 
     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);
 
     spin_lock(&server->srv_lock);
     server->tcpStatus = CifsExiting;
     spin_unlock(&server->srv_lock);
 
     cifs_crypto_secmech_release(server);
 
     kfree(server->session_key.response);
     server->session_key.response = NULL;
     server->session_key.len = 0;
     kfree(server->hostname);
 
     task = xchg(&server->tsk, NULL);
     if (task)
         send_sig(SIGKILL, task, 1);
 }
 
 struct TCP_Server_Info *
 cifs_get_tcp_session(struct smb3_fs_context *ctx,
              struct TCP_Server_Info *primary_server)
 {
     struct TCP_Server_Info *tcp_ses = NULL;
     int rc;
 
     cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
 
     /* see if we already have a matching tcp_ses */
     tcp_ses = cifs_find_tcp_session(ctx);
     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->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
     if (!tcp_ses->hostname) {
         rc = -ENOMEM;
         goto out_err;
     }
 
     if (ctx->nosharesock)
         tcp_ses->nosharesock = true;
 
     tcp_ses->ops = ctx->ops;
     tcp_ses->vals = ctx->vals;
     cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
 
     tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
     tcp_ses->noblockcnt = ctx->rootfs;
     tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
     tcp_ses->noautotune = ctx->noautotune;
     tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
     tcp_ses->rdma = ctx->rdma;
     tcp_ses->in_flight = 0;
     tcp_ses->max_in_flight = 0;
     tcp_ses->credits = 1;
     if (primary_server) {
         spin_lock(&cifs_tcp_ses_lock);
         ++primary_server->srv_count;
         spin_unlock(&cifs_tcp_ses_lock);
         tcp_ses->primary_server = primary_server;
     }
     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,
         ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
     memcpy(tcp_ses->server_RFC1001_name,
         ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
     tcp_ses->session_estab = false;
     tcp_ses->sequence_number = 0;
     tcp_ses->reconnect_instance = 1;
     tcp_ses->lstrp = jiffies;
     tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
     spin_lock_init(&tcp_ses->req_lock);
     spin_lock_init(&tcp_ses->srv_lock);
     spin_lock_init(&tcp_ses->mid_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);
     INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
     INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
     mutex_init(&tcp_ses->reconnect_mutex);
 #ifdef CONFIG_CIFS_DFS_UPCALL
     mutex_init(&tcp_ses->refpath_lock);
 #endif
     memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
            sizeof(tcp_ses->srcaddr));
     memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
         sizeof(tcp_ses->dstaddr));
     if (ctx->use_client_guid)
         memcpy(tcp_ses->client_guid, ctx->client_guid,
                SMB2_CLIENT_GUID_SIZE);
     else
         generate_random_uuid(tcp_ses->client_guid);
     /*
      * 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 (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
         ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
         tcp_ses->echo_interval = ctx->echo_interval * HZ;
     else
         tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
     if (tcp_ses->rdma) {
 #ifndef CONFIG_CIFS_SMB_DIRECT
         cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
         rc = -ENOENT;
         goto out_err_crypto_release;
 #endif
         tcp_ses->smbd_conn = smbd_get_connection(
             tcp_ses, (struct sockaddr *)&ctx->dstaddr);
         if (tcp_ses->smbd_conn) {
             cifs_dbg(VFS, "RDMA transport established\n");
             rc = 0;
             goto smbd_connected;
         } else {
             rc = -ENOENT;
             goto out_err_crypto_release;
         }
     }
     rc = ip_connect(tcp_ses);
     if (rc < 0) {
         cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
         goto out_err_crypto_release;
     }
 smbd_connected:
     /*
      * 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->min_offload = ctx->min_offload;
     /*
      * 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 update of tcpStatus
      */
     spin_lock(&tcp_ses->srv_lock);
     tcp_ses->tcpStatus = CifsNeedNegotiate;
     spin_unlock(&tcp_ses->srv_lock);
 
     if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
         tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
     else
         tcp_ses->max_credits = ctx->max_credits;
 
     tcp_ses->nr_targets = 1;
     tcp_ses->ignore_signature = ctx->ignore_signature;
     /* 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);
 
     /* queue echo request delayed work */
     queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
 
     /* queue dns resolution delayed work */
     cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
          __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
 
     queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
 
     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 (CIFS_SERVER_IS_CHAN(tcp_ses))
             cifs_put_tcp_session(tcp_ses->primary_server, false);
         kfree(tcp_ses->hostname);
         if (tcp_ses->ssocket)
             sock_release(tcp_ses->ssocket);
         kfree(tcp_ses);
     }
     return ERR_PTR(rc);
 }
 
 /* this function must be called with ses_lock held */
 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 {
     if (ctx->sectype != Unspecified &&
         ctx->sectype != ses->sectype)
         return 0;
 
     /*
      * If an existing session is limited to less channels than
      * requested, it should not be reused
      */
     spin_lock(&ses->chan_lock);
     if (ses->chan_max < ctx->max_channels) {
         spin_unlock(&ses->chan_lock);
         return 0;
     }
     spin_unlock(&ses->chan_lock);
 
     switch (ses->sectype) {
     case Kerberos:
         if (!uid_eq(ctx->cred_uid, ses->cred_uid))
             return 0;
         break;
     default:
         /* NULL username means anonymous session */
         if (ses->user_name == NULL) {
             if (!ctx->nullauth)
                 return 0;
             break;
         }
 
         /* anything else takes username/password */
         if (strncmp(ses->user_name,
                 ctx->username ? ctx->username : "",
                 CIFS_MAX_USERNAME_LEN))
             return 0;
         if ((ctx->username && strlen(ctx->username) != 0) &&
             ses->password != NULL &&
             strncmp(ses->password,
                 ctx->password ? ctx->password : "",
                 CIFS_MAX_PASSWORD_LEN))
             return 0;
     }
     return 1;
 }
 
 /**
  * cifs_setup_ipc - helper to setup the IPC tcon for the session
  * @ses: smb session to issue the request on
  * @ctx: the superblock configuration context to use for building the
  *       new tree connection for the IPC (interprocess communication RPC)
  *
  * A new IPC connection is made and stored in the session
  * tcon_ipc. The IPC tcon has the same lifetime as the session.
  */
 static int
 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 {
     int rc = 0, xid;
     struct cifs_tcon *tcon;
     char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
     bool seal = false;
     struct TCP_Server_Info *server = ses->server;
 
     /*
      * If the mount request that resulted in the creation of the
      * session requires encryption, force IPC to be encrypted too.
      */
     if (ctx->seal) {
         if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
             seal = true;
         else {
             cifs_server_dbg(VFS,
                  "IPC: server doesn't support encryption\n");
             return -EOPNOTSUPP;
         }
     }
 
     tcon = tconInfoAlloc();
     if (tcon == NULL)
         return -ENOMEM;
 
     scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
 
     xid = get_xid();
     tcon->ses = ses;
     tcon->ipc = true;
     tcon->seal = seal;
     rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
     free_xid(xid);
 
     if (rc) {
         cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
         tconInfoFree(tcon);
         goto out;
     }
 
     cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
 
     ses->tcon_ipc = tcon;
 out:
     return rc;
 }
 
 /**
  * cifs_free_ipc - helper to release the session IPC tcon
  * @ses: smb session to unmount the IPC from
  *
  * Needs to be called everytime a session is destroyed.
  *
  * On session close, the IPC is closed and the server must release all tcons of the session.
  * No need to send a tree disconnect here.
  *
  * Besides, it will make the server to not close durable and resilient files on session close, as
  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
  */
 static int
 cifs_free_ipc(struct cifs_ses *ses)
 {
     struct cifs_tcon *tcon = ses->tcon_ipc;
 
     if (tcon == NULL)
         return 0;
 
     tconInfoFree(tcon);
     ses->tcon_ipc = NULL;
     return 0;
 }
 
 static struct cifs_ses *
 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
     struct cifs_ses *ses;
 
     spin_lock(&cifs_tcp_ses_lock);
     list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
         spin_lock(&ses->ses_lock);
         if (ses->ses_status == SES_EXITING) {
             spin_unlock(&ses->ses_lock);
             continue;
         }
         if (!match_session(ses, ctx)) {
             spin_unlock(&ses->ses_lock);
             continue;
         }
         spin_unlock(&ses->ses_lock);
 
         ++ses->ses_count;
         spin_unlock(&cifs_tcp_ses_lock);
         return ses;
     }
     spin_unlock(&cifs_tcp_ses_lock);
     return NULL;
 }
 
 void cifs_put_smb_ses(struct cifs_ses *ses)
 {
     unsigned int rc, xid;
     unsigned int chan_count;
     struct TCP_Server_Info *server = ses->server;
 
     spin_lock(&ses->ses_lock);
     if (ses->ses_status == SES_EXITING) {
         spin_unlock(&ses->ses_lock);
         return;
     }
     spin_unlock(&ses->ses_lock);
 
     cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
     cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
 
     spin_lock(&cifs_tcp_ses_lock);
     if (--ses->ses_count > 0) {
         spin_unlock(&cifs_tcp_ses_lock);
         return;
     }
     spin_unlock(&cifs_tcp_ses_lock);
 
     /* ses_count can never go negative */
     WARN_ON(ses->ses_count < 0);
 
     if (ses->ses_status == SES_GOOD)
         ses->ses_status = SES_EXITING;
 
     cifs_free_ipc(ses);
 
     if (ses->ses_status == SES_EXITING && server->ops->logoff) {
         xid = get_xid();
         rc = server->ops->logoff(xid, ses);
         if (rc)
             cifs_server_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);
 
     chan_count = ses->chan_count;
 
     /* close any extra channels */
     if (chan_count > 1) {
         int i;
 
         for (i = 1; i < chan_count; i++) {
             if (ses->chans[i].iface) {
                 kref_put(&ses->chans[i].iface->refcount, release_iface);
                 ses->chans[i].iface = NULL;
             }
             cifs_put_tcp_session(ses->chans[i].server, 0);
             ses->chans[i].server = NULL;
         }
     }
 
     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 smb3_fs_context *ctx, struct cifs_ses *ses)
 {
     int rc = 0;
     int is_domain = 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;
         }
         is_domain = 1;
     }
 
     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;
     }
 
     ctx->username = kstrndup(payload, len, GFP_KERNEL);
     if (!ctx->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__, ctx->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(ctx->username);
         ctx->username = NULL;
         goto out_key_put;
     }
 
     ++delim;
     ctx->password = kstrndup(delim, len, GFP_KERNEL);
     if (!ctx->password) {
         cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
              len);
         rc = -ENOMEM;
         kfree(ctx->username);
         ctx->username = NULL;
         goto out_key_put;
     }
 
     /*
      * If we have a domain key then we must set the domainName in the
      * for the request.
      */
     if (is_domain && ses->domainName) {
         ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
         if (!ctx->domainname) {
             cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
                  len);
             rc = -ENOMEM;
             kfree(ctx->username);
             ctx->username = NULL;
             kfree_sensitive(ctx->password);
             ctx->password = NULL;
             goto out_key_put;
         }
     }
 
     strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
 
 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 smb3_fs_context *ctx __attribute__((unused)),
            struct cifs_ses *ses __attribute__((unused)))
 {
     return -ENOSYS;
 }
 #endif /* CONFIG_KEYS */
 
 /**
  * cifs_get_smb_ses - get a session matching @ctx data from @server
  * @server: server to setup the session to
  * @ctx: superblock configuration context to use to setup the session
  *
  * This function assumes it is being called from cifs_mount() where we
  * already got a server reference (server refcount +1). See
  * cifs_get_tcon() for refcount explanations.
  */
 struct cifs_ses *
 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
     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, ctx);
     if (ses) {
         cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
              ses->ses_status);
 
         spin_lock(&ses->chan_lock);
         if (cifs_chan_needs_reconnect(ses, server)) {
             spin_unlock(&ses->chan_lock);
             cifs_dbg(FYI, "Session needs reconnect\n");
 
             mutex_lock(&ses->session_mutex);
             rc = cifs_negotiate_protocol(xid, ses, server);
             if (rc) {
                 mutex_unlock(&ses->session_mutex);
                 /* problem -- put our ses reference */
                 cifs_put_smb_ses(ses);
                 free_xid(xid);
                 return ERR_PTR(rc);
             }
 
             rc = cifs_setup_session(xid, ses, server,
                         ctx->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);
 
             spin_lock(&ses->chan_lock);
         }
         spin_unlock(&ses->chan_lock);
 
         /* 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->ip_addr, "%pI6", &addr6->sin6_addr);
     else
         sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
 
     if (ctx->username) {
         ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
         if (!ses->user_name)
             goto get_ses_fail;
     }
 
     /* ctx->password freed at unmount */
     if (ctx->password) {
         ses->password = kstrdup(ctx->password, GFP_KERNEL);
         if (!ses->password)
             goto get_ses_fail;
     }
     if (ctx->domainname) {
         ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
         if (!ses->domainName)
             goto get_ses_fail;
     }
 
     strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
 
     if (ctx->domainauto)
         ses->domainAuto = ctx->domainauto;
     ses->cred_uid = ctx->cred_uid;
     ses->linux_uid = ctx->linux_uid;
 
     ses->sectype = ctx->sectype;
     ses->sign = ctx->sign;
 
     /* add server as first channel */
     spin_lock(&ses->chan_lock);
     ses->chans[0].server = server;
     ses->chan_count = 1;
     ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
     ses->chans_need_reconnect = 1;
     spin_unlock(&ses->chan_lock);
 
     mutex_lock(&ses->session_mutex);
     rc = cifs_negotiate_protocol(xid, ses, server);
     if (!rc)
         rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
     mutex_unlock(&ses->session_mutex);
 
     /* each channel uses a different signing key */
     spin_lock(&ses->chan_lock);
     memcpy(ses->chans[0].signkey, ses->smb3signingkey,
            sizeof(ses->smb3signingkey));
     spin_unlock(&ses->chan_lock);
 
     if (rc)
         goto get_ses_fail;
 
     /*
      * success, put it on the list and add it as first channel
      * note: the session becomes active soon after this. So you'll
      * need to lock before changing something in the session.
      */
     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);
 
     cifs_setup_ipc(ses, ctx);
 
     return ses;
 
 get_ses_fail:
     sesInfoFree(ses);
     free_xid(xid);
     return ERR_PTR(rc);
 }
 
 /* this function must be called with tc_lock held */
 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 {
     if (tcon->status == TID_EXITING)
         return 0;
     if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
         return 0;
     if (tcon->seal != ctx->seal)
         return 0;
     if (tcon->snapshot_time != ctx->snapshot_time)
         return 0;
     if (tcon->handle_timeout != ctx->handle_timeout)
         return 0;
     if (tcon->no_lease != ctx->no_lease)
         return 0;
     if (tcon->nodelete != ctx->nodelete)
         return 0;
     return 1;
 }
 
 static struct cifs_tcon *
 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 {
     struct cifs_tcon *tcon;
 
     spin_lock(&cifs_tcp_ses_lock);
     list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
         spin_lock(&tcon->tc_lock);
         if (!match_tcon(tcon, ctx)) {
             spin_unlock(&tcon->tc_lock);
             continue;
         }
         ++tcon->tc_count;
         spin_unlock(&tcon->tc_lock);
         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;
 
     /*
      * IPC tcon share the lifetime of their session and are
      * destroyed in the session put function
      */
     if (tcon == NULL || tcon->ipc)
         return;
 
     ses = tcon->ses;
     cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
     spin_lock(&cifs_tcp_ses_lock);
     spin_lock(&tcon->tc_lock);
     if (--tcon->tc_count > 0) {
         spin_unlock(&tcon->tc_lock);
         spin_unlock(&cifs_tcp_ses_lock);
         return;
     }
 
     /* tc_count can never go negative */
     WARN_ON(tcon->tc_count < 0);
 
     list_del_init(&tcon->tcon_list);
     spin_unlock(&tcon->tc_lock);
     spin_unlock(&cifs_tcp_ses_lock);
 
     /* cancel polling of interfaces */
     cancel_delayed_work_sync(&tcon->query_interfaces);
 
     if (tcon->use_witness) {
         int rc;
 
         rc = cifs_swn_unregister(tcon);
         if (rc < 0) {
             cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
                     __func__, rc);
         }
     }
 
     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);
 }
 
 /**
  * cifs_get_tcon - get a tcon matching @ctx data from @ses
  * @ses: smb session to issue the request on
  * @ctx: the superblock configuration context to use for building the
  *
  * - tcon refcount is the number of mount points using the tcon.
  * - ses refcount is the number of tcon using the session.
  *
  * 1. This function assumes it is being called from cifs_mount() where
  *    we already got a session reference (ses refcount +1).
  *
  * 2. Since we're in the context of adding a mount point, the end
  *    result should be either:
  *
  * a) a new tcon already allocated with refcount=1 (1 mount point) and
  *    its session refcount incremented (1 new tcon). This +1 was
  *    already done in (1).
  *
  * b) an existing tcon with refcount+1 (add a mount point to it) and
  *    identical ses refcount (no new tcon). Because of (1) we need to
  *    decrement the ses refcount.
  */
 static struct cifs_tcon *
 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 {
     int rc, xid;
     struct cifs_tcon *tcon;
 
     tcon = cifs_find_tcon(ses, ctx);
     if (tcon) {
         /*
          * tcon has refcount already incremented but we need to
          * decrement extra ses reference gotten by caller (case b)
          */
         cifs_dbg(FYI, "Found match on UNC path\n");
         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 (ctx->snapshot_time) {
         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 = ctx->snapshot_time;
     }
 
     if (ctx->handle_timeout) {
         if (ses->server->vals->protocol_id == 0) {
             cifs_dbg(VFS,
                  "Use SMB2.1 or later for handle timeout option\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         } else
             tcon->handle_timeout = ctx->handle_timeout;
     }
 
     tcon->ses = ses;
     if (ctx->password) {
         tcon->password = kstrdup(ctx->password, GFP_KERNEL);
         if (!tcon->password) {
             rc = -ENOMEM;
             goto out_fail;
         }
     }
 
     if (ctx->seal) {
         if (ses->server->vals->protocol_id == 0) {
             cifs_dbg(VFS,
                  "SMB3 or later required for encryption\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         } 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;
         }
     }
 
     if (ctx->linux_ext) {
         if (ses->server->posix_ext_supported) {
             tcon->posix_extensions = true;
             pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
         } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
             (strcmp(ses->server->vals->version_string,
              SMB3ANY_VERSION_STRING) == 0) ||
             (strcmp(ses->server->vals->version_string,
              SMBDEFAULT_VERSION_STRING) == 0)) {
             cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         } else {
             cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
                 "disabled but required for POSIX extensions\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         }
     }
 
     xid = get_xid();
     rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
                         ctx->local_nls);
     free_xid(xid);
     cifs_dbg(FYI, "Tcon rc = %d\n", rc);
     if (rc)
         goto out_fail;
 
     tcon->use_persistent = false;
     /* check if SMB2 or later, CIFS does not support persistent handles */
     if (ctx->persistent) {
         if (ses->server->vals->protocol_id == 0) {
             cifs_dbg(VFS,
                  "SMB3 or later required for persistent handles\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         } 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;
         }
     } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
          && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
          && (ctx->nopersistent == false)) {
         cifs_dbg(FYI, "enabling persistent handles\n");
         tcon->use_persistent = true;
     } else if (ctx->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;
     }
 
     tcon->use_witness = false;
     if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
         if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
             if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
                 /*
                  * Set witness in use flag in first place
                  * to retry registration in the echo task
                  */
                 tcon->use_witness = true;
                 /* And try to register immediately */
                 rc = cifs_swn_register(tcon);
                 if (rc < 0) {
                     cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
                     goto out_fail;
                 }
             } else {
                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
                 rc = -EOPNOTSUPP;
                 goto out_fail;
             }
         } else {
             cifs_dbg(VFS, "SMB3 or later required for witness option\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         }
     }
 
     /* If the user really knows what they are doing they can override */
     if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
         if (ctx->cache_ro)
             cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
         else if (ctx->cache_rw)
             cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
     }
 
     if (ctx->no_lease) {
         if (ses->server->vals->protocol_id == 0) {
             cifs_dbg(VFS,
                 "SMB2 or later required for nolease option\n");
             rc = -EOPNOTSUPP;
             goto out_fail;
         } else
             tcon->no_lease = ctx->no_lease;
     }
 
     /*
      * 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 = ctx->retry;
     tcon->nocase = ctx->nocase;
     tcon->broken_sparse_sup = ctx->no_sparse;
     if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
         tcon->nohandlecache = ctx->nohandlecache;
     else
         tcon->nohandlecache = true;
     tcon->nodelete = ctx->nodelete;
     tcon->local_lease = ctx->local_lease;
     INIT_LIST_HEAD(&tcon->pending_opens);
 
     /* schedule query interfaces poll */
     INIT_DELAYED_WORK(&tcon->query_interfaces,
               smb2_query_server_interfaces);
     queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
                (SMB_INTERFACE_POLL_INTERVAL * HZ));
 
     spin_lock(&cifs_tcp_ses_lock);
     list_add(&tcon->tcon_list, &ses->tcon_list);
     spin_unlock(&cifs_tcp_ses_lock);
 
     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 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;
     unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
     unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
 
     if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
         return 0;
 
     if (old->mnt_cifs_serverino_autodisabled)
         newflags &= ~CIFS_MOUNT_SERVER_INUM;
 
     if (oldflags != newflags)
         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->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
         return 0;
 
     if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
         return 0;
 
     if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
         !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
         return 0;
 
     if (old->ctx->file_mode != new->ctx->file_mode ||
         old->ctx->dir_mode != new->ctx->dir_mode)
         return 0;
 
     if (strcmp(old->local_nls->charset, new->local_nls->charset))
         return 0;
 
     if (old->ctx->acregmax != new->ctx->acregmax)
         return 0;
     if (old->ctx->acdirmax != new->ctx->acdirmax)
         return 0;
     if (old->ctx->closetimeo != new->ctx->closetimeo)
         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) &&
         old->prepath;
     bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
         new->prepath;
 
     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 = data;
     struct smb3_fs_context *ctx;
     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 (tlink == NULL) {
         /* can not match superblock if tlink were ever null */
         spin_unlock(&cifs_tcp_ses_lock);
         return 0;
     }
     tcon = tlink_tcon(tlink);
     ses = tcon->ses;
     tcp_srv = ses->server;
 
     ctx = mnt_data->ctx;
 
     spin_lock(&tcp_srv->srv_lock);
     spin_lock(&ses->ses_lock);
     spin_lock(&tcon->tc_lock);
     if (!match_server(tcp_srv, ctx) ||
         !match_session(ses, ctx) ||
         !match_tcon(tcon, ctx) ||
         !match_prepath(sb, mnt_data)) {
         rc = 0;
         goto out;
     }
 
     rc = compare_mount_options(sb, mnt_data);
 out:
     spin_unlock(&tcon->tc_lock);
     spin_unlock(&ses->ses_lock);
     spin_unlock(&tcp_srv->srv_lock);
 
     spin_unlock(&cifs_tcp_ses_lock);
     cifs_put_tlink(tlink);
     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)
 {
 }
 #endif
 
 /* See RFC1001 section 14 on representation of Netbios names */
 static void rfc1002mangle(char *target, char *source, unsigned int length)
 {
     unsigned int i, j;
 
     for (i = 0, j = 0; i < (length); i++) {
         /* mask a nibble at a time and encode */
         target[j] = 'A' + (0x0F & (source[i] >> 4));
         target[j+1] = 'A' + (0x0F & source[i]);
         j += 2;
     }
 
 }
 
 static int
 bind_socket(struct TCP_Server_Info *server)
 {
     int rc = 0;
     if (server->srcaddr.ss_family != AF_UNSPEC) {
         /* Bind to the specified local IP address */
         struct socket *socket = server->ssocket;
         rc = socket->ops->bind(socket,
                        (struct sockaddr *) &server->srcaddr,
                        sizeof(server->srcaddr));
         if (rc < 0) {
             struct sockaddr_in *saddr4;
             struct sockaddr_in6 *saddr6;
             saddr4 = (struct sockaddr_in *)&server->srcaddr;
             saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
             if (saddr6->sin6_family == AF_INET6)
                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
                      &saddr6->sin6_addr, rc);
             else
                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
                      &saddr4->sin_addr.s_addr, rc);
         }
     }
     return rc;
 }
 
 static int
 ip_rfc1001_connect(struct TCP_Server_Info *server)
 {
     int rc = 0;
     /*
      * some servers require RFC1001 sessinit before sending
      * negprot - BB check reconnection in case where second
      * sessinit is sent but no second negprot
      */
     struct rfc1002_session_packet *ses_init_buf;
     struct smb_hdr *smb_buf;
     ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
                    GFP_KERNEL);
     if (ses_init_buf) {
         ses_init_buf->trailer.session_req.called_len = 32;
 
         if (server->server_RFC1001_name[0] != 0)
             rfc1002mangle(ses_init_buf->trailer.
                       session_req.called_name,
                       server->server_RFC1001_name,
                       RFC1001_NAME_LEN_WITH_NULL);
         else
             rfc1002mangle(ses_init_buf->trailer.
                       session_req.called_name,
                       DEFAULT_CIFS_CALLED_NAME,
                       RFC1001_NAME_LEN_WITH_NULL);
 
         ses_init_buf->trailer.session_req.calling_len = 32;
 
         /*
          * calling name ends in null (byte 16) from old smb
          * convention.
          */
         if (server->workstation_RFC1001_name[0] != 0)
             rfc1002mangle(ses_init_buf->trailer.
                       session_req.calling_name,
                       server->workstation_RFC1001_name,
                       RFC1001_NAME_LEN_WITH_NULL);
         else
             rfc1002mangle(ses_init_buf->trailer.
                       session_req.calling_name,
                       "LINUX_CIFS_CLNT",
                       RFC1001_NAME_LEN_WITH_NULL);
 
         ses_init_buf->trailer.session_req.scope1 = 0;
         ses_init_buf->trailer.session_req.scope2 = 0;
         smb_buf = (struct smb_hdr *)ses_init_buf;
 
         /* sizeof RFC1002_SESSION_REQUEST with no scope */
         smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
         rc = smb_send(server, smb_buf, 0x44);
         kfree(ses_init_buf);
         /*
          * RFC1001 layer in at least one server
          * requires very short break before negprot
          * presumably because not expecting negprot
          * to follow so fast.  This is a simple
          * solution that works without
          * complicating the code and causes no
          * significant slowing down on mount
          * for everyone else
          */
         usleep_range(1000, 2000);
     }
     /*
      * else the negprot may still work without this
      * even though malloc failed
      */
 
     return rc;
 }
 
 static int
 generic_ip_connect(struct TCP_Server_Info *server)
 {
     int rc = 0;
     __be16 sport;
     int slen, sfamily;
     struct socket *socket = server->ssocket;
     struct sockaddr *saddr;
 
     saddr = (struct sockaddr *) &server->dstaddr;
 
     if (server->dstaddr.ss_family == AF_INET6) {
         struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
 
         sport = ipv6->sin6_port;
         slen = sizeof(struct sockaddr_in6);
         sfamily = AF_INET6;
         cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
                 ntohs(sport));
     } else {
         struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
 
         sport = ipv4->sin_port;
         slen = sizeof(struct sockaddr_in);
         sfamily = AF_INET;
         cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
                 ntohs(sport));
     }
 
     if (socket == NULL) {
         rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
                    IPPROTO_TCP, &socket, 1);
         if (rc < 0) {
             cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
             server->ssocket = NULL;
             return rc;
         }
 
         /* BB other socket options to set KEEPALIVE, NODELAY? */
         cifs_dbg(FYI, "Socket created\n");
         server->ssocket = socket;
         socket->sk->sk_allocation = GFP_NOFS;
         if (sfamily == AF_INET6)
             cifs_reclassify_socket6(socket);
         else
             cifs_reclassify_socket4(socket);
     }
 
     rc = bind_socket(server);
     if (rc < 0)
         return rc;
 
     /*
      * Eventually check for other socket options to change from
      * the default. sock_setsockopt not used because it expects
      * user space buffer
      */
     socket->sk->sk_rcvtimeo = 7 * HZ;
     socket->sk->sk_sndtimeo = 5 * HZ;
 
     /* make the bufsizes depend on wsize/rsize and max requests */
     if (server->noautotune) {
         if (socket->sk->sk_sndbuf < (200 * 1024))
             socket->sk->sk_sndbuf = 200 * 1024;
         if (socket->sk->sk_rcvbuf < (140 * 1024))
             socket->sk->sk_rcvbuf = 140 * 1024;
     }
 
     if (server->tcp_nodelay)
         tcp_sock_set_nodelay(socket->sk);
 
     cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
          socket->sk->sk_sndbuf,
          socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
 
     rc = socket->ops->connect(socket, saddr, slen,
                   server->noblockcnt ? O_NONBLOCK : 0);
     /*
      * When mounting SMB root file systems, we do not want to block in
      * connect. Otherwise bail out and then let cifs_reconnect() perform
      * reconnect failover - if possible.
      */
     if (server->noblockcnt && rc == -EINPROGRESS)
         rc = 0;
     if (rc < 0) {
         cifs_dbg(FYI, "Error %d connecting to server\n", rc);
         trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
         sock_release(socket);
         server->ssocket = NULL;
         return rc;
     }
     trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
     if (sport == htons(RFC1001_PORT))
         rc = ip_rfc1001_connect(server);
 
     return rc;
 }
 
 static int
 ip_connect(struct TCP_Server_Info *server)
 {
     __be16 *sport;
     struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
     struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
 
     if (server->dstaddr.ss_family == AF_INET6)
         sport = &addr6->sin6_port;
     else
         sport = &addr->sin_port;
 
     if (*sport == 0) {
         int rc;
 
         /* try with 445 port at first */
         *sport = htons(CIFS_PORT);
 
         rc = generic_ip_connect(server);
         if (rc >= 0)
             return rc;
 
         /* if it failed, try with 139 port */
         *sport = htons(RFC1001_PORT);
     }
 
     return generic_ip_connect(server);
 }
 
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
               struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 {
     /*
      * If we are reconnecting then should we check to see if
      * any requested capabilities changed locally e.g. via
      * remount but we can not do much about it here
      * if they have (even if we could detect it by the following)
      * Perhaps we could add a backpointer to array of sb from tcon
      * or if we change to make all sb to same share the same
      * sb as NFS - then we only have one backpointer to sb.
      * What if we wanted to mount the server share twice once with
      * and once without posixacls or posix paths?
      */
     __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
 
     if (ctx && ctx->no_linux_ext) {
         tcon->fsUnixInfo.Capability = 0;
         tcon->unix_ext = 0; /* Unix Extensions disabled */
         cifs_dbg(FYI, "Linux protocol extensions disabled\n");
         return;
     } else if (ctx)
         tcon->unix_ext = 1; /* Unix Extensions supported */
 
     if (!tcon->unix_ext) {
         cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
         return;
     }
 
     if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
         __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
         cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
         /*
          * check for reconnect case in which we do not
          * want to change the mount behavior if we can avoid it
          */
         if (ctx == NULL) {
             /*
              * turn off POSIX ACL and PATHNAMES if not set
              * originally at mount time
              */
             if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
             if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
                     cifs_dbg(VFS, "POSIXPATH support change\n");
                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
             } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
                 cifs_dbg(VFS, "possible reconnect error\n");
                 cifs_dbg(VFS, "server disabled POSIX path support\n");
             }
         }
 
         if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
             cifs_dbg(VFS, "per-share encryption not supported yet\n");
 
         cap &= CIFS_UNIX_CAP_MASK;
         if (ctx && ctx->no_psx_acl)
             cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
         else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
             cifs_dbg(FYI, "negotiated posix acl support\n");
             if (cifs_sb)
                 cifs_sb->mnt_cifs_flags |=
                     CIFS_MOUNT_POSIXACL;
         }
 
         if (ctx && ctx->posix_paths == 0)
             cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
         else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
             cifs_dbg(FYI, "negotiate posix pathnames\n");
             if (cifs_sb)
                 cifs_sb->mnt_cifs_flags |=
                     CIFS_MOUNT_POSIX_PATHS;
         }
 
         cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
 #ifdef CONFIG_CIFS_DEBUG2
         if (cap & CIFS_UNIX_FCNTL_CAP)
             cifs_dbg(FYI, "FCNTL cap\n");
         if (cap & CIFS_UNIX_EXTATTR_CAP)
             cifs_dbg(FYI, "EXTATTR cap\n");
         if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
             cifs_dbg(FYI, "POSIX path cap\n");
         if (cap & CIFS_UNIX_XATTR_CAP)
             cifs_dbg(FYI, "XATTR cap\n");
         if (cap & CIFS_UNIX_POSIX_ACL_CAP)
             cifs_dbg(FYI, "POSIX ACL cap\n");
         if (cap & CIFS_UNIX_LARGE_READ_CAP)
             cifs_dbg(FYI, "very large read cap\n");
         if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
             cifs_dbg(FYI, "very large write cap\n");
         if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
             cifs_dbg(FYI, "transport encryption cap\n");
         if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
             cifs_dbg(FYI, "mandatory transport encryption cap\n");
 #endif /* CIFS_DEBUG2 */
         if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
             if (ctx == NULL)
                 cifs_dbg(FYI, "resetting capabilities failed\n");
             else
                 cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
 
         }
     }
 }
 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 
 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
 {
     struct smb3_fs_context *ctx = cifs_sb->ctx;
 
     INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
 
     spin_lock_init(&cifs_sb->tlink_tree_lock);
     cifs_sb->tlink_tree = RB_ROOT;
 
     cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
          ctx->file_mode, ctx->dir_mode);
 
     /* this is needed for ASCII cp to Unicode converts */
     if (ctx->iocharset == NULL) {
         /* load_nls_default cannot return null */
         cifs_sb->local_nls = load_nls_default();
     } else {
         cifs_sb->local_nls = load_nls(ctx->iocharset);
         if (cifs_sb->local_nls == NULL) {
             cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
                  ctx->iocharset);
             return -ELIBACC;
         }
     }
     ctx->local_nls = cifs_sb->local_nls;
 
     smb3_update_mnt_flags(cifs_sb);
 
     if (ctx->direct_io)
         cifs_dbg(FYI, "mounting share using direct i/o\n");
     if (ctx->cache_ro) {
         cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
     } else if (ctx->cache_rw) {
         cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
         cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
                         CIFS_MOUNT_RW_CACHE);
     }
 
     if ((ctx->cifs_acl) && (ctx->dynperm))
         cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
 
     if (ctx->prepath) {
         cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
         if (cifs_sb->prepath == NULL)
             return -ENOMEM;
         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
     }
 
     return 0;
 }
 
 /* Release all succeed connections */
 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
 {
     int rc = 0;
 
     if (mnt_ctx->tcon)
         cifs_put_tcon(mnt_ctx->tcon);
     else if (mnt_ctx->ses)
         cifs_put_smb_ses(mnt_ctx->ses);
     else if (mnt_ctx->server)
         cifs_put_tcp_session(mnt_ctx->server, 0);
     mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
     free_xid(mnt_ctx->xid);
 }
 
 /* Get connections for tcp, ses and tcon */
 static int mount_get_conns(struct mount_ctx *mnt_ctx)
 {
     int rc = 0;
     struct TCP_Server_Info *server = NULL;
     struct cifs_ses *ses = NULL;
     struct cifs_tcon *tcon = NULL;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     unsigned int xid;
 
     xid = get_xid();
 
     /* get a reference to a tcp session */
     server = cifs_get_tcp_session(ctx, NULL);
     if (IS_ERR(server)) {
         rc = PTR_ERR(server);
         server = NULL;
         goto out;
     }
 
     /* get a reference to a SMB session */
     ses = cifs_get_smb_ses(server, ctx);
     if (IS_ERR(ses)) {
         rc = PTR_ERR(ses);
         ses = NULL;
         goto out;
     }
 
     if ((ctx->persistent == true) && (!(ses->server->capabilities &
                         SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
         cifs_server_dbg(VFS, "persistent handles not supported by server\n");
         rc = -EOPNOTSUPP;
         goto out;
     }
 
     /* search for existing tcon to this server share */
     tcon = cifs_get_tcon(ses, ctx);
     if (IS_ERR(tcon)) {
         rc = PTR_ERR(tcon);
         tcon = NULL;
         goto out;
     }
 
     /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
     if (tcon->posix_extensions)
         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
 
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
     /* tell server which Unix caps we support */
     if (cap_unix(tcon->ses)) {
         /*
          * reset of caps checks mount to see if unix extensions disabled
          * for just this mount.
          */
         reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
         spin_lock(&tcon->ses->server->srv_lock);
         if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
             (le64_to_cpu(tcon->fsUnixInfo.Capability) &
              CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
             spin_unlock(&tcon->ses->server->srv_lock);
             rc = -EACCES;
             goto out;
         }
         spin_unlock(&tcon->ses->server->srv_lock);
     } else
 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
         tcon->unix_ext = 0; /* server does not support them */
 
     /* do not care if a following call succeed - informational */
     if (!tcon->pipe && server->ops->qfs_tcon) {
         server->ops->qfs_tcon(xid, tcon, cifs_sb);
         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
             if (tcon->fsDevInfo.DeviceCharacteristics &
                 cpu_to_le32(FILE_READ_ONLY_DEVICE))
                 cifs_dbg(VFS, "mounted to read only share\n");
             else if ((cifs_sb->mnt_cifs_flags &
                   CIFS_MOUNT_RW_CACHE) == 0)
                 cifs_dbg(VFS, "read only mount of RW share\n");
             /* no need to log a RW mount of a typical RW share */
         }
     }
 
     /*
      * Clamp the rsize/wsize mount arguments if they are too big for the server
      * and set the rsize/wsize to the negotiated values if not passed in by
      * the user on mount
      */
     if ((cifs_sb->ctx->wsize == 0) ||
         (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
         cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
     if ((cifs_sb->ctx->rsize == 0) ||
         (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
         cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
 
     /*
      * The cookie is initialized from volume info returned above.
      * Inside cifs_fscache_get_super_cookie it checks
      * that we do not get super cookie twice.
      */
     if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
         cifs_fscache_get_super_cookie(tcon);
 
 out:
     mnt_ctx->server = server;
     mnt_ctx->ses = ses;
     mnt_ctx->tcon = tcon;
     mnt_ctx->xid = xid;
 
     return rc;
 }
 
 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
                  struct cifs_tcon *tcon)
 {
     struct tcon_link *tlink;
 
     /* hang the tcon off of the superblock */
     tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
     if (tlink == NULL)
         return -ENOMEM;
 
     tlink->tl_uid = ses->linux_uid;
     tlink->tl_tcon = tcon;
     tlink->tl_time = jiffies;
     set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
     set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
 
     cifs_sb->master_tlink = tlink;
     spin_lock(&cifs_sb->tlink_tree_lock);
     tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
     spin_unlock(&cifs_sb->tlink_tree_lock);
 
     queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
                 TLINK_IDLE_EXPIRE);
     return 0;
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 /* Get unique dfs connections */
 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
 {
     int rc;
 
     mnt_ctx->fs_ctx->nosharesock = true;
     rc = mount_get_conns(mnt_ctx);
     if (mnt_ctx->server) {
         cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
         spin_lock(&mnt_ctx->server->srv_lock);
         mnt_ctx->server->is_dfs_conn = true;
         spin_unlock(&mnt_ctx->server->srv_lock);
     }
     return rc;
 }
 
 /*
  * cifs_build_path_to_root returns full path to root when we do not have an
  * existing connection (tcon)
  */
 static char *
 build_unc_path_to_root(const struct smb3_fs_context *ctx,
                const struct cifs_sb_info *cifs_sb, bool useppath)
 {
     char *full_path, *pos;
     unsigned int pplen = useppath && ctx->prepath ?
         strlen(ctx->prepath) + 1 : 0;
     unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
 
     if (unc_len > MAX_TREE_SIZE)
         return ERR_PTR(-EINVAL);
 
     full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
     if (full_path == NULL)
         return ERR_PTR(-ENOMEM);
 
     memcpy(full_path, ctx->UNC, unc_len);
     pos = full_path + unc_len;
 
     if (pplen) {
         *pos = CIFS_DIR_SEP(cifs_sb);
         memcpy(pos + 1, ctx->prepath, pplen);
         pos += pplen;
     }
 
     *pos = '\0'; /* add trailing null */
     convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
     cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
     return full_path;
 }
 
 /*
  * expand_dfs_referral - Update cifs_sb from dfs referral path
  *
  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
  * submount.  Otherwise it will be left untouched.
  */
 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
                    struct dfs_info3_param *referral)
 {
     int rc;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     char *fake_devname = NULL, *mdata = NULL;
 
     mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
                        &fake_devname);
     if (IS_ERR(mdata)) {
         rc = PTR_ERR(mdata);
         mdata = NULL;
     } else {
         /*
          * We can not clear out the whole structure since we no longer have an explicit
          * function to parse a mount-string. Instead we need to clear out the individual
          * fields that are no longer valid.
          */
         kfree(ctx->prepath);
         ctx->prepath = NULL;
         rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
     }
     kfree(fake_devname);
     kfree(cifs_sb->ctx->mount_options);
     cifs_sb->ctx->mount_options = mdata;
 
     return rc;
 }
 #endif
 
 /* TODO: all callers to this are broken. We are not parsing mount_options here
  * we should pass a clone of the original context?
  */
 int
 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
 {
     int rc;
 
     if (devname) {
         cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
         rc = smb3_parse_devname(devname, ctx);
         if (rc) {
             cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
             return rc;
         }
     }
 
     if (mntopts) {
         char *ip;
 
         rc = smb3_parse_opt(mntopts, "ip", &ip);
         if (rc) {
             cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
             return rc;
         }
 
         rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
         kfree(ip);
         if (!rc) {
             cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
             return -EINVAL;
         }
     }
 
     if (ctx->nullauth) {
         cifs_dbg(FYI, "Anonymous login\n");
         kfree(ctx->username);
         ctx->username = NULL;
     } else if (ctx->username) {
         /* BB fixme parse for domain name here */
         cifs_dbg(FYI, "Username: %s\n", ctx->username);
     } else {
         cifs_dbg(VFS, "No username specified\n");
     /* In userspace mount helper we can get user name from alternate
        locations such as env variables and files on disk */
         return -EINVAL;
     }
 
     return 0;
 }
 
 static int
 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
                     unsigned int xid,
                     struct cifs_tcon *tcon,
                     struct cifs_sb_info *cifs_sb,
                     char *full_path,
                     int added_treename)
 {
     int rc;
     char *s;
     char sep, tmp;
     int skip = added_treename ? 1 : 0;
 
     sep = CIFS_DIR_SEP(cifs_sb);
     s = full_path;
 
     rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
     while (rc == 0) {
         /* skip separators */
         while (*s == sep)
             s++;
         if (!*s)
             break;
         /* next separator */
         while (*s && *s != sep)
             s++;
         /*
          * if the treename is added, we then have to skip the first
          * part within the separators
          */
         if (skip) {
             skip = 0;
             continue;
         }
         /*
          * temporarily null-terminate the path at the end of
          * the current component
          */
         tmp = *s;
         *s = 0;
         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
                              full_path);
         *s = tmp;
     }
     return rc;
 }
 
 /*
  * Check if path is remote (i.e. a DFS share).
  *
  * Return -EREMOTE if it is, otherwise 0 or -errno.
  */
 static int is_path_remote(struct mount_ctx *mnt_ctx)
 {
     int rc;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct TCP_Server_Info *server = mnt_ctx->server;
     unsigned int xid = mnt_ctx->xid;
     struct cifs_tcon *tcon = mnt_ctx->tcon;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     char *full_path;
 #ifdef CONFIG_CIFS_DFS_UPCALL
     bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
 #endif
 
     if (!server->ops->is_path_accessible)
         return -EOPNOTSUPP;
 
     /*
      * cifs_build_path_to_root works only when we have a valid tcon
      */
     full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
                         tcon->Flags & SMB_SHARE_IS_IN_DFS);
     if (full_path == NULL)
         return -ENOMEM;
 
     cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
 
     rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
                          full_path);
 #ifdef CONFIG_CIFS_DFS_UPCALL
     if (nodfs) {
         if (rc == -EREMOTE)
             rc = -EOPNOTSUPP;
         goto out;
     }
 
     /* path *might* exist with non-ASCII characters in DFS root
      * try again with full path (only if nodfs is not set) */
     if (rc == -ENOENT && is_tcon_dfs(tcon))
         rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
                             full_path);
 #endif
     if (rc != 0 && rc != -EREMOTE)
         goto out;
 
     if (rc != -EREMOTE) {
         rc = cifs_are_all_path_components_accessible(server, xid, tcon,
             cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
         if (rc != 0) {
             cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
             cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
             rc = 0;
         }
     }
 
 out:
     kfree(full_path);
     return rc;
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 static void set_root_ses(struct mount_ctx *mnt_ctx)
 {
     if (mnt_ctx->ses) {
         spin_lock(&cifs_tcp_ses_lock);
         mnt_ctx->ses->ses_count++;
         spin_unlock(&cifs_tcp_ses_lock);
         dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
     }
     mnt_ctx->root_ses = mnt_ctx->ses;
 }
 
 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
 {
     int rc;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 
     *isdfs = true;
 
     rc = mount_get_conns(mnt_ctx);
     /*
      * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
      * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
      *
      * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
      * to respond with PATH_NOT_COVERED to requests that include the prefix.
      */
     if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
         dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
                ctx->UNC + 1, NULL, root_tl)) {
         if (rc)
             return rc;
         /* Check if it is fully accessible and then mount it */
         rc = is_path_remote(mnt_ctx);
         if (!rc)
             *isdfs = false;
         else if (rc != -EREMOTE)
             return rc;
     }
     return 0;
 }
 
 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
                   const char *ref_path, struct dfs_cache_tgt_iterator *tit)
 {
     int rc;
     struct dfs_info3_param ref = {};
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     char *oldmnt = cifs_sb->ctx->mount_options;
 
     cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
          dfs_cache_get_tgt_name(tit));
 
     rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
     if (rc)
         goto out;
 
     rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
     if (rc)
         goto out;
 
     /* Connect to new target only if we were redirected (e.g. mount options changed) */
     if (oldmnt != cifs_sb->ctx->mount_options) {
         mount_put_conns(mnt_ctx);
         rc = mount_get_dfs_conns(mnt_ctx);
     }
     if (!rc) {
         if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
             set_root_ses(mnt_ctx);
         rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
                           cifs_remap(cifs_sb), ref_path, tit);
     }
 
 out:
     free_dfs_info_param(&ref);
     return rc;
 }
 
 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
 {
     int rc;
     char *full_path;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     struct dfs_cache_tgt_iterator *tit;
 
     /* Put initial connections as they might be shared with other mounts.  We need unique dfs
      * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
      * now on.
      */
     mount_put_conns(mnt_ctx);
     mount_get_dfs_conns(mnt_ctx);
     set_root_ses(mnt_ctx);
 
     full_path = build_unc_path_to_root(ctx, cifs_sb, true);
     if (IS_ERR(full_path))
         return PTR_ERR(full_path);
 
     mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
                                 cifs_remap(cifs_sb));
     if (IS_ERR(mnt_ctx->origin_fullpath)) {
         rc = PTR_ERR(mnt_ctx->origin_fullpath);
         mnt_ctx->origin_fullpath = NULL;
         goto out;
     }
 
     /* Try all dfs root targets */
     for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
          tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
         rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
         if (!rc) {
             mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
             if (!mnt_ctx->leaf_fullpath)
                 rc = -ENOMEM;
             break;
         }
     }
 
 out:
     kfree(full_path);
     return rc;
 }
 
 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
 {
     int rc;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     char *full_path;
     struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
     struct dfs_cache_tgt_iterator *tit;
 
     full_path = build_unc_path_to_root(ctx, cifs_sb, true);
     if (IS_ERR(full_path))
         return PTR_ERR(full_path);
 
     kfree(mnt_ctx->leaf_fullpath);
     mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
                               cifs_remap(cifs_sb));
     if (IS_ERR(mnt_ctx->leaf_fullpath)) {
         rc = PTR_ERR(mnt_ctx->leaf_fullpath);
         mnt_ctx->leaf_fullpath = NULL;
         goto out;
     }
 
     /* Get referral from dfs link */
     rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
                 cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
     if (rc)
         goto out;
 
     /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
      * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
      * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
      * STATUS_PATH_NOT_COVERED."
      */
     for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
          tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
         rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
         if (!rc) {
             rc = is_path_remote(mnt_ctx);
             if (!rc || rc == -EREMOTE)
                 break;
         }
     }
 
 out:
     kfree(full_path);
     dfs_cache_free_tgts(&tl);
     return rc;
 }
 
 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
 {
     int rc;
     struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
     struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
     char *full_path;
     int num_links = 0;
 
     full_path = build_unc_path_to_root(ctx, cifs_sb, true);
     if (IS_ERR(full_path))
         return PTR_ERR(full_path);
 
     kfree(mnt_ctx->origin_fullpath);
     mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
                                 cifs_remap(cifs_sb));
     kfree(full_path);
 
     if (IS_ERR(mnt_ctx->origin_fullpath)) {
         rc = PTR_ERR(mnt_ctx->origin_fullpath);
         mnt_ctx->origin_fullpath = NULL;
         return rc;
     }
 
     do {
         rc = __follow_dfs_link(mnt_ctx);
         if (!rc || rc != -EREMOTE)
             break;
     } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
 
     return rc;
 }
 
 /* Set up DFS referral paths for failover */
 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
 {
     struct TCP_Server_Info *server = mnt_ctx->server;
 
     mutex_lock(&server->refpath_lock);
     server->origin_fullpath = mnt_ctx->origin_fullpath;
     server->leaf_fullpath = mnt_ctx->leaf_fullpath;
     server->current_fullpath = mnt_ctx->leaf_fullpath;
     mutex_unlock(&server->refpath_lock);
     mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
 }
 
 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 {
     int rc;
     struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
     struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
     bool isdfs;
 
     rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
     if (rc)
         goto error;
     if (!isdfs)
         goto out;
 
     /* proceed as DFS mount */
     uuid_gen(&mnt_ctx.mount_id);
     rc = connect_dfs_root(&mnt_ctx, &tl);
     dfs_cache_free_tgts(&tl);
 
     if (rc)
         goto error;
 
     rc = is_path_remote(&mnt_ctx);
     if (rc)
         rc = follow_dfs_link(&mnt_ctx);
     if (rc)
         goto error;
 
     setup_server_referral_paths(&mnt_ctx);
     /*
      * After reconnecting to a different server, unique ids won't match anymore, so we disable
      * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
      */
     cifs_autodisable_serverino(cifs_sb);
     /*
      * Force the use of prefix path to support failover on DFS paths that resolve to targets
      * that have different prefix paths.
      */
     cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
     kfree(cifs_sb->prepath);
     cifs_sb->prepath = ctx->prepath;
     ctx->prepath = NULL;
     uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
 
 out:
     free_xid(mnt_ctx.xid);
     cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
     return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
 
 error:
     dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
     kfree(mnt_ctx.origin_fullpath);
     kfree(mnt_ctx.leaf_fullpath);
     mount_put_conns(&mnt_ctx);
     return rc;
 }
 #else
 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 {
     int rc = 0;
     struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
 
     rc = mount_get_conns(&mnt_ctx);
     if (rc)
         goto error;
 
     if (mnt_ctx.tcon) {
         rc = is_path_remote(&mnt_ctx);
         if (rc == -EREMOTE)
             rc = -EOPNOTSUPP;
         if (rc)
             goto error;
     }
 
     free_xid(mnt_ctx.xid);
     return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
 
 error:
     mount_put_conns(&mnt_ctx);
     return rc;
 }
 #endif
 
 /*
  * Issue a TREE_CONNECT request.
  */
 int
 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
      const char *tree, struct cifs_tcon *tcon,
      const struct nls_table *nls_codepage)
 {
     struct smb_hdr *smb_buffer;
     struct smb_hdr *smb_buffer_response;
     TCONX_REQ *pSMB;
     TCONX_RSP *pSMBr;
     unsigned char *bcc_ptr;
     int rc = 0;
     int length;
     __u16 bytes_left, count;
 
     if (ses == NULL)
         return -EIO;
 
     smb_buffer = cifs_buf_get();
     if (smb_buffer == NULL)
         return -ENOMEM;
 
     smb_buffer_response = smb_buffer;
 
     header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
             NULL /*no tid */ , 4 /*wct */ );
 
     smb_buffer->Mid = get_next_mid(ses->server);
     smb_buffer->Uid = ses->Suid;
     pSMB = (TCONX_REQ *) smb_buffer;
     pSMBr = (TCONX_RSP *) smb_buffer_response;
 
     pSMB->AndXCommand = 0xFF;
     pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
     bcc_ptr = &pSMB->Password[0];
     if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
         *bcc_ptr = 0; /* password is null byte */
         bcc_ptr++;              /* skip password */
         /* already aligned so no need to do it below */
     }
 
     if (ses->server->sign)
         smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 
     if (ses->capabilities & CAP_STATUS32) {
         smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
     }
     if (ses->capabilities & CAP_DFS) {
         smb_buffer->Flags2 |= SMBFLG2_DFS;
     }
     if (ses->capabilities & CAP_UNICODE) {
         smb_buffer->Flags2 |= SMBFLG2_UNICODE;
         length =
             cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
             6 /* max utf8 char length in bytes */ *
             (/* server len*/ + 256 /* share len */), nls_codepage);
         bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
         bcc_ptr += 2;   /* skip trailing null */
     } else {        /* ASCII */
         strcpy(bcc_ptr, tree);
         bcc_ptr += strlen(tree) + 1;
     }
     strcpy(bcc_ptr, "?????");
     bcc_ptr += strlen("?????");
     bcc_ptr += 1;
     count = bcc_ptr - &pSMB->Password[0];
     be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
     pSMB->ByteCount = cpu_to_le16(count);
 
     rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
              0);
 
     /* above now done in SendReceive */
     if (rc == 0) {
         bool is_unicode;
 
         tcon->tid = smb_buffer_response->Tid;
         bcc_ptr = pByteArea(smb_buffer_response);
         bytes_left = get_bcc(smb_buffer_response);
         length = strnlen(bcc_ptr, bytes_left - 2);
         if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
             is_unicode = true;
         else
             is_unicode = false;
 
 
         /* skip service field (NB: this field is always ASCII) */
         if (length == 3) {
             if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
                 (bcc_ptr[2] == 'C')) {
                 cifs_dbg(FYI, "IPC connection\n");
                 tcon->ipc = true;
                 tcon->pipe = true;
             }
         } else if (length == 2) {
             if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
                 /* the most common case */
                 cifs_dbg(FYI, "disk share connection\n");
             }
         }
         bcc_ptr += length + 1;
         bytes_left -= (length + 1);
         strscpy(tcon->treeName, tree, sizeof(tcon->treeName));
 
         /* mostly informational -- no need to fail on error here */
         kfree(tcon->nativeFileSystem);
         tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
                               bytes_left, is_unicode,
                               nls_codepage);
 
         cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
 
         if ((smb_buffer_response->WordCount == 3) ||
              (smb_buffer_response->WordCount == 7))
             /* field is in same location */
             tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
         else
             tcon->Flags = 0;
         cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
     }
 
     cifs_buf_release(smb_buffer);
     return rc;
 }
 
 static void delayed_free(struct rcu_head *p)
 {
     struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
 
     unload_nls(cifs_sb->local_nls);
     smb3_cleanup_fs_context(cifs_sb->ctx);
     kfree(cifs_sb);
 }
 
 void
 cifs_umount(struct cifs_sb_info *cifs_sb)
 {
     struct rb_root *root = &cifs_sb->tlink_tree;
     struct rb_node *node;
     struct tcon_link *tlink;
 
     cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
 
     spin_lock(&cifs_sb->tlink_tree_lock);
     while ((node = rb_first(root))) {
         tlink = rb_entry(node, struct tcon_link, tl_rbnode);
         cifs_get_tlink(tlink);
         clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
         rb_erase(node, root);
 
         spin_unlock(&cifs_sb->tlink_tree_lock);
         cifs_put_tlink(tlink);
         spin_lock(&cifs_sb->tlink_tree_lock);
     }
     spin_unlock(&cifs_sb->tlink_tree_lock);
 
     kfree(cifs_sb->prepath);
 #ifdef CONFIG_CIFS_DFS_UPCALL
     dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
 #endif
     call_rcu(&cifs_sb->rcu, delayed_free);
 }
 
 int
 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
             struct TCP_Server_Info *server)
 {
     int rc = 0;
 
     if (!server->ops->need_neg || !server->ops->negotiate)
         return -ENOSYS;
 
     /* only send once per connect */
     spin_lock(&server->srv_lock);
     if (!server->ops->need_neg(server) ||
         server->tcpStatus != CifsNeedNegotiate) {
         spin_unlock(&server->srv_lock);
         return 0;
     }
     server->tcpStatus = CifsInNegotiate;
     spin_unlock(&server->srv_lock);
 
     rc = server->ops->negotiate(xid, ses, server);
     if (rc == 0) {
         spin_lock(&server->srv_lock);
         if (server->tcpStatus == CifsInNegotiate)
             server->tcpStatus = CifsGood;
         else
             rc = -EHOSTDOWN;
         spin_unlock(&server->srv_lock);
     } else {
         spin_lock(&server->srv_lock);
         if (server->tcpStatus == CifsInNegotiate)
             server->tcpStatus = CifsNeedNegotiate;
         spin_unlock(&server->srv_lock);
     }
 
     return rc;
 }
 
 int
 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
            struct TCP_Server_Info *server,
            struct nls_table *nls_info)
 {
     int rc = -ENOSYS;
     struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
     struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
     bool is_binding = false;
 
     spin_lock(&ses->ses_lock);
     if (server->dstaddr.ss_family == AF_INET6)
         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
     else
         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
 
     if (ses->ses_status != SES_GOOD &&
         ses->ses_status != SES_NEW &&
         ses->ses_status != SES_NEED_RECON) {
         spin_unlock(&ses->ses_lock);
         return 0;
     }
 
     /* only send once per connect */
     spin_lock(&ses->chan_lock);
     if (CIFS_ALL_CHANS_GOOD(ses) ||
         cifs_chan_in_reconnect(ses, server)) {
         spin_unlock(&ses->chan_lock);
         spin_unlock(&ses->ses_lock);
         return 0;
     }
     is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
     cifs_chan_set_in_reconnect(ses, server);
     spin_unlock(&ses->chan_lock);
 
     if (!is_binding)
         ses->ses_status = SES_IN_SETUP;
     spin_unlock(&ses->ses_lock);
 
     if (!is_binding) {
         ses->capabilities = server->capabilities;
         if (!linuxExtEnabled)
             ses->capabilities &= (~server->vals->cap_unix);
 
         if (ses->auth_key.response) {
             cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
                  ses->auth_key.response);
             kfree(ses->auth_key.response);
             ses->auth_key.response = NULL;
             ses->auth_key.len = 0;
         }
     }
 
     cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
          server->sec_mode, server->capabilities, server->timeAdj);
 
     if (server->ops->sess_setup)
         rc = server->ops->sess_setup(xid, ses, server, nls_info);
 
     if (rc) {
         cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
         spin_lock(&ses->ses_lock);
         if (ses->ses_status == SES_IN_SETUP)
             ses->ses_status = SES_NEED_RECON;
         spin_lock(&ses->chan_lock);
         cifs_chan_clear_in_reconnect(ses, server);
         spin_unlock(&ses->chan_lock);
         spin_unlock(&ses->ses_lock);
     } else {
         spin_lock(&ses->ses_lock);
         if (ses->ses_status == SES_IN_SETUP)
             ses->ses_status = SES_GOOD;
         spin_lock(&ses->chan_lock);
         cifs_chan_clear_in_reconnect(ses, server);
         cifs_chan_clear_need_reconnect(ses, server);
         spin_unlock(&ses->chan_lock);
         spin_unlock(&ses->ses_lock);
     }
 
     return rc;
 }
 
 static int
 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
 {
     ctx->sectype = ses->sectype;
 
     /* krb5 is special, since we don't need username or pw */
     if (ctx->sectype == Kerberos)
         return 0;
 
     return cifs_set_cifscreds(ctx, ses);
 }
 
 static struct cifs_tcon *
 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 {
     int rc;
     struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
     struct cifs_ses *ses;
     struct cifs_tcon *tcon = NULL;
     struct smb3_fs_context *ctx;
 
     ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
     if (ctx == NULL)
         return ERR_PTR(-ENOMEM);
 
     ctx->local_nls = cifs_sb->local_nls;
     ctx->linux_uid = fsuid;
     ctx->cred_uid = fsuid;
     ctx->UNC = master_tcon->treeName;
     ctx->retry = master_tcon->retry;
     ctx->nocase = master_tcon->nocase;
     ctx->nohandlecache = master_tcon->nohandlecache;
     ctx->local_lease = master_tcon->local_lease;
     ctx->no_lease = master_tcon->no_lease;
     ctx->resilient = master_tcon->use_resilient;
     ctx->persistent = master_tcon->use_persistent;
     ctx->handle_timeout = master_tcon->handle_timeout;
     ctx->no_linux_ext = !master_tcon->unix_ext;
     ctx->linux_ext = master_tcon->posix_extensions;
     ctx->sectype = master_tcon->ses->sectype;
     ctx->sign = master_tcon->ses->sign;
     ctx->seal = master_tcon->seal;
     ctx->witness = master_tcon->use_witness;
 
     rc = cifs_set_vol_auth(ctx, master_tcon->ses);
     if (rc) {
         tcon = ERR_PTR(rc);
         goto out;
     }
 
     /* get a reference for the same TCP session */
     spin_lock(&cifs_tcp_ses_lock);
     ++master_tcon->ses->server->srv_count;
     spin_unlock(&cifs_tcp_ses_lock);
 
     ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
     if (IS_ERR(ses)) {
         tcon = (struct cifs_tcon *)ses;
         cifs_put_tcp_session(master_tcon->ses->server, 0);
         goto out;
     }
 
     tcon = cifs_get_tcon(ses, ctx);
     if (IS_ERR(tcon)) {
         cifs_put_smb_ses(ses);
         goto out;
     }
 
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
     if (cap_unix(ses))
         reset_cifs_unix_caps(0, tcon, NULL, ctx);
 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 
 out:
     kfree(ctx->username);
     kfree_sensitive(ctx->password);
     kfree(ctx);
 
     return tcon;
 }
 
 struct cifs_tcon *
 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
 {
     return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
 }
 
 /* find and return a tlink with given uid */
 static struct tcon_link *
 tlink_rb_search(struct rb_root *root, kuid_t uid)
 {
     struct rb_node *node = root->rb_node;
     struct tcon_link *tlink;
 
     while (node) {
         tlink = rb_entry(node, struct tcon_link, tl_rbnode);
 
         if (uid_gt(tlink->tl_uid, uid))
             node = node->rb_left;
         else if (uid_lt(tlink->tl_uid, uid))
             node = node->rb_right;
         else
             return tlink;
     }
     return NULL;
 }
 
 /* insert a tcon_link into the tree */
 static void
 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
 {
     struct rb_node **new = &(root->rb_node), *parent = NULL;
     struct tcon_link *tlink;
 
     while (*new) {
         tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
         parent = *new;
 
         if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
             new = &((*new)->rb_left);
         else
             new = &((*new)->rb_right);
     }
 
     rb_link_node(&new_tlink->tl_rbnode, parent, new);
     rb_insert_color(&new_tlink->tl_rbnode, root);
 }
 
 /*
  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
  * current task.
  *
  * If the superblock doesn't refer to a multiuser mount, then just return
  * the master tcon for the mount.
  *
  * First, search the rbtree for an existing tcon for this fsuid. If one
  * exists, then check to see if it's pending construction. If it is then wait
  * for construction to complete. Once it's no longer pending, check to see if
  * it failed and either return an error or retry construction, depending on
  * the timeout.
  *
  * If one doesn't exist then insert a new tcon_link struct into the tree and
  * try to construct a new one.
  */
 struct tcon_link *
 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
 {
     int ret;
     kuid_t fsuid = current_fsuid();
     struct tcon_link *tlink, *newtlink;
 
     if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
         return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
 
     spin_lock(&cifs_sb->tlink_tree_lock);
     tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
     if (tlink)
         cifs_get_tlink(tlink);
     spin_unlock(&cifs_sb->tlink_tree_lock);
 
     if (tlink == NULL) {
         newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
         if (newtlink == NULL)
             return ERR_PTR(-ENOMEM);
         newtlink->tl_uid = fsuid;
         newtlink->tl_tcon = ERR_PTR(-EACCES);
         set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
         set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
         cifs_get_tlink(newtlink);
 
         spin_lock(&cifs_sb->tlink_tree_lock);
         /* was one inserted after previous search? */
         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
         if (tlink) {
             cifs_get_tlink(tlink);
             spin_unlock(&cifs_sb->tlink_tree_lock);
             kfree(newtlink);
             goto wait_for_construction;
         }
         tlink = newtlink;
         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
         spin_unlock(&cifs_sb->tlink_tree_lock);
     } else {
 wait_for_construction:
         ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
                   TASK_INTERRUPTIBLE);
         if (ret) {
             cifs_put_tlink(tlink);
             return ERR_PTR(-ERESTARTSYS);
         }
 
         /* if it's good, return it */
         if (!IS_ERR(tlink->tl_tcon))
             return tlink;
 
         /* return error if we tried this already recently */
         if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
             cifs_put_tlink(tlink);
             return ERR_PTR(-EACCES);
         }
 
         if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
             goto wait_for_construction;
     }
 
     tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
     clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
     wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
 
     if (IS_ERR(tlink->tl_tcon)) {
         cifs_put_tlink(tlink);
         return ERR_PTR(-EACCES);
     }
 
     return tlink;
 }
 
 /*
  * periodic workqueue job that scans tcon_tree for a superblock and closes
  * out tcons.
  */
 static void
 cifs_prune_tlinks(struct work_struct *work)
 {
     struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
                             prune_tlinks.work);
     struct rb_root *root = &cifs_sb->tlink_tree;
     struct rb_node *node;
     struct rb_node *tmp;
     struct tcon_link *tlink;
 
     /*
      * Because we drop the spinlock in the loop in order to put the tlink
      * it's not guarded against removal of links from the tree. The only
      * places that remove entries from the tree are this function and
      * umounts. Because this function is non-reentrant and is canceled
      * before umount can proceed, this is safe.
      */
     spin_lock(&cifs_sb->tlink_tree_lock);
     node = rb_first(root);
     while (node != NULL) {
         tmp = node;
         node = rb_next(tmp);
         tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
 
         if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
             atomic_read(&tlink->tl_count) != 0 ||
             time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
             continue;
 
         cifs_get_tlink(tlink);
         clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
         rb_erase(tmp, root);
 
         spin_unlock(&cifs_sb->tlink_tree_lock);
         cifs_put_tlink(tlink);
         spin_lock(&cifs_sb->tlink_tree_lock);
     }
     spin_unlock(&cifs_sb->tlink_tree_lock);
 
     queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
                 TLINK_IDLE_EXPIRE);
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 /* Update dfs referral path of superblock */
 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
                   const char *target)
 {
     int rc = 0;
     size_t len = strlen(target);
     char *refpath, *npath;
 
     if (unlikely(len < 2 || *target != '\\'))
         return -EINVAL;
 
     if (target[1] == '\\') {
         len += 1;
         refpath = kmalloc(len, GFP_KERNEL);
         if (!refpath)
             return -ENOMEM;
 
         scnprintf(refpath, len, "%s", target);
     } else {
         len += sizeof("\\");
         refpath = kmalloc(len, GFP_KERNEL);
         if (!refpath)
             return -ENOMEM;
 
         scnprintf(refpath, len, "\\%s", target);
     }
 
     npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
     kfree(refpath);
 
     if (IS_ERR(npath)) {
         rc = PTR_ERR(npath);
     } else {
         mutex_lock(&server->refpath_lock);
         kfree(server->leaf_fullpath);
         server->leaf_fullpath = npath;
         mutex_unlock(&server->refpath_lock);
         server->current_fullpath = server->leaf_fullpath;
     }
     return rc;
 }
 
 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
                        size_t tcp_host_len, char *share, bool *target_match)
 {
     int rc = 0;
     const char *dfs_host;
     size_t dfs_host_len;
 
     *target_match = true;
     extract_unc_hostname(share, &dfs_host, &dfs_host_len);
 
     /* Check if hostnames or addresses match */
     if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
         cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
              dfs_host, (int)tcp_host_len, tcp_host);
         rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
         if (rc)
             cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
     }
     return rc;
 }
 
 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
                      struct dfs_cache_tgt_list *tl)
 {
     int rc;
     struct TCP_Server_Info *server = tcon->ses->server;
     const struct smb_version_operations *ops = server->ops;
     struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
     char *share = NULL, *prefix = NULL;
     const char *tcp_host;
     size_t tcp_host_len;
     struct dfs_cache_tgt_iterator *tit;
     bool target_match;
 
     extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
 
     tit = dfs_cache_get_tgt_iterator(tl);
     if (!tit) {
         rc = -ENOENT;
         goto out;
     }
 
     /* Try to tree connect to all dfs targets */
     for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
         const char *target = dfs_cache_get_tgt_name(tit);
         struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
 
         kfree(share);
         kfree(prefix);
         share = prefix = NULL;
 
         /* Check if share matches with tcp ses */
         rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
         if (rc) {
             cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
             break;
         }
 
         rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
                          &target_match);
         if (rc)
             break;
         if (!target_match) {
             rc = -EHOSTUNREACH;
             continue;
         }
 
         if (ipc->need_reconnect) {
             scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
             rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
             if (rc)
                 break;
         }
 
         scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
         if (!islink) {
             rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
             break;
         }
         /*
          * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
          * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
          * reconnect so either the demultiplex thread or the echo worker will reconnect to
          * newly resolved target.
          */
         if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
                    NULL, &ntl)) {
             rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
             if (rc)
                 continue;
             rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
             if (!rc)
                 rc = cifs_update_super_prepath(cifs_sb, prefix);
         } else {
             /* Target is another dfs share */
             rc = update_server_fullpath(server, cifs_sb, target);
             dfs_cache_free_tgts(tl);
 
             if (!rc) {
                 rc = -EREMOTE;
                 list_replace_init(&ntl.tl_list, &tl->tl_list);
             } else
                 dfs_cache_free_tgts(&ntl);
         }
         break;
     }
 
 out:
     kfree(share);
     kfree(prefix);
 
     return rc;
 }
 
 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
                    struct dfs_cache_tgt_list *tl)
 {
     int rc;
     int num_links = 0;
     struct TCP_Server_Info *server = tcon->ses->server;
 
     do {
         rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
         if (!rc || rc != -EREMOTE)
             break;
     } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
     /*
      * If we couldn't tree connect to any targets from last referral path, then retry from
      * original referral path.
      */
     if (rc && server->current_fullpath != server->origin_fullpath) {
         server->current_fullpath = server->origin_fullpath;
         cifs_signal_cifsd_for_reconnect(server, true);
     }
 
     dfs_cache_free_tgts(tl);
     return rc;
 }
 
 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
 {
     int rc;
     struct TCP_Server_Info *server = tcon->ses->server;
     const struct smb_version_operations *ops = server->ops;
     struct super_block *sb = NULL;
     struct cifs_sb_info *cifs_sb;
     struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
     char *tree;
     struct dfs_info3_param ref = {0};
 
     /* only send once per connect */
     spin_lock(&tcon->tc_lock);
     if (tcon->ses->ses_status != SES_GOOD ||
         (tcon->status != TID_NEW &&
         tcon->status != TID_NEED_TCON)) {
         spin_unlock(&tcon->tc_lock);
         return 0;
     }
     tcon->status = TID_IN_TCON;
     spin_unlock(&tcon->tc_lock);
 
     tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
     if (!tree) {
         rc = -ENOMEM;
         goto out;
     }
 
     if (tcon->ipc) {
         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
         goto out;
     }
 
     sb = cifs_get_tcp_super(server);
     if (IS_ERR(sb)) {
         rc = PTR_ERR(sb);
         cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
         goto out;
     }
 
     cifs_sb = CIFS_SB(sb);
 
     /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
     if (!server->current_fullpath ||
         dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
         goto out;
     }
 
     rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
                      &tl);
     free_dfs_info_param(&ref);
 
 out:
     kfree(tree);
     cifs_put_tcp_super(sb);
 
     if (rc) {
         spin_lock(&tcon->tc_lock);
         if (tcon->status == TID_IN_TCON)
             tcon->status = TID_NEED_TCON;
         spin_unlock(&tcon->tc_lock);
     } else {
         spin_lock(&tcon->tc_lock);
         if (tcon->status == TID_IN_TCON)
             tcon->status = TID_GOOD;
         spin_unlock(&tcon->tc_lock);
         tcon->need_reconnect = false;
     }
 
     return rc;
 }
 #else
 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
 {
     int rc;
     const struct smb_version_operations *ops = tcon->ses->server->ops;
 
     /* only send once per connect */
     spin_lock(&tcon->tc_lock);
     if (tcon->ses->ses_status != SES_GOOD ||
         (tcon->status != TID_NEW &&
         tcon->status != TID_NEED_TCON)) {
         spin_unlock(&tcon->tc_lock);
         return 0;
     }
     tcon->status = TID_IN_TCON;
     spin_unlock(&tcon->tc_lock);
 
     rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
     if (rc) {
         spin_lock(&tcon->tc_lock);
         if (tcon->status == TID_IN_TCON)
             tcon->status = TID_NEED_TCON;
         spin_unlock(&tcon->tc_lock);
     } else {
         spin_lock(&tcon->tc_lock);
         if (tcon->status == TID_IN_TCON)
             tcon->status = TID_GOOD;
         tcon->need_reconnect = false;
         spin_unlock(&tcon->tc_lock);
     }
 
     return rc;
 }
 #endif