fs/cifs/cifsfs.c

   1 /*
   2  *   fs/cifs/cifsfs.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2008
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   Common Internet FileSystem (CIFS) client
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 /* Note that BB means BUGBUG (ie something to fix eventually) */
  25
  26 #include <linux/module.h>
  27 #include <linux/fs.h>
  28 #include <linux/mount.h>
  29 #include <linux/slab.h>
  30 #include <linux/init.h>
  31 #include <linux/list.h>
  32 #include <linux/seq_file.h>
  33 #include <linux/vfs.h>
  34 #include <linux/mempool.h>
  35 #include <linux/delay.h>
  36 #include <linux/kthread.h>
  37 #include <linux/freezer.h>
  38 #include <linux/namei.h>
  39 #include <net/ipv6.h>
  40 #include "cifsfs.h"
  41 #include "cifspdu.h"
  42 #define DECLARE_GLOBALS_HERE
  43 #include "cifsglob.h"
  44 #include "cifsproto.h"
  45 #include "cifs_debug.h"
  46 #include "cifs_fs_sb.h"
  47 #include <linux/mm.h>
  48 #include <linux/key-type.h>
  49 #include "cifs_spnego.h"
  50 #include "fscache.h"
  51 #define CIFS_MAGIC_NUMBER 0xFF534D42    /* the first four bytes of SMB PDUs */
  52
  53 int cifsFYI = 0;
  54 int cifsERROR = 1;
  55 int traceSMB = 0;
  56 unsigned int oplockEnabled = 1;
  57 unsigned int linuxExtEnabled = 1;
  58 unsigned int lookupCacheEnabled = 1;
  59 unsigned int multiuser_mount = 0;
  60 unsigned int global_secflags = CIFSSEC_DEF;
  61 /* unsigned int ntlmv2_support = 0; */
  62 unsigned int sign_CIFS_PDUs = 1;
  63 static const struct super_operations cifs_super_ops;
  64 unsigned int CIFSMaxBufSize = CIFS_MAX_MSGSIZE;
  65 module_param(CIFSMaxBufSize, int, 0);
  66 MODULE_PARM_DESC(CIFSMaxBufSize, "Network buffer size (not including header). "
  67                                  "Default: 16384 Range: 8192 to 130048");
  68 unsigned int cifs_min_rcv = CIFS_MIN_RCV_POOL;
  69 module_param(cifs_min_rcv, int, 0);
  70 MODULE_PARM_DESC(cifs_min_rcv, "Network buffers in pool. Default: 4 Range: "
  71                                 "1 to 64");
  72 unsigned int cifs_min_small = 30;
  73 module_param(cifs_min_small, int, 0);
  74 MODULE_PARM_DESC(cifs_min_small, "Small network buffers in pool. Default: 30 "
  75                                  "Range: 2 to 256");
  76 unsigned int cifs_max_pending = CIFS_MAX_REQ;
  77 module_param(cifs_max_pending, int, 0);
  78 MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server. "
  79                                    "Default: 50 Range: 2 to 256");
  80 unsigned short echo_retries = 5;
  81 module_param(echo_retries, ushort, 0644);
  82 MODULE_PARM_DESC(echo_retries, "Number of echo attempts before giving up and "
  83                                "reconnecting server. Default: 5. 0 means "
  84                                "never reconnect.");
  85 extern mempool_t *cifs_sm_req_poolp;
  86 extern mempool_t *cifs_req_poolp;
  87 extern mempool_t *cifs_mid_poolp;
  88
  89 static int
  90 cifs_read_super(struct super_block *sb)
  91 {
  92         struct inode *inode;
  93         struct cifs_sb_info *cifs_sb;
  94         int rc = 0;
  95
  96         cifs_sb = CIFS_SB(sb);
  97
  98         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIXACL)
  99                 sb->s_flags |= MS_POSIXACL;
 100
 101         if (cifs_sb_master_tcon(cifs_sb)->ses->capabilities & CAP_LARGE_FILES)
 102                 sb->s_maxbytes = MAX_LFS_FILESIZE;
 103         else
 104                 sb->s_maxbytes = MAX_NON_LFS;
 105
 106         /* BB FIXME fix time_gran to be larger for LANMAN sessions */
 107         sb->s_time_gran = 100;
 108
 109         sb->s_magic = CIFS_MAGIC_NUMBER;
 110         sb->s_op = &cifs_super_ops;
 111         sb->s_bdi = &cifs_sb->bdi;
 112         sb->s_blocksize = CIFS_MAX_MSGSIZE;
 113         sb->s_blocksize_bits = 14;      /* default 2**14 = CIFS_MAX_MSGSIZE */
 114         inode = cifs_root_iget(sb);
 115
 116         if (IS_ERR(inode)) {
 117                 rc = PTR_ERR(inode);
 118                 inode = NULL;
 119                 goto out_no_root;
 120         }
 121
 122         sb->s_root = d_alloc_root(inode);
 123
 124         if (!sb->s_root) {
 125                 rc = -ENOMEM;
 126                 goto out_no_root;
 127         }
 128
 129         /* do that *after* d_alloc_root() - we want NULL ->d_op for root here */
 130         if (cifs_sb_master_tcon(cifs_sb)->nocase)
 131                 sb->s_d_op = &cifs_ci_dentry_ops;
 132         else
 133                 sb->s_d_op = &cifs_dentry_ops;
 134
 135 #ifdef CIFS_NFSD_EXPORT
 136         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 137                 cFYI(1, "export ops supported");
 138                 sb->s_export_op = &cifs_export_ops;
 139         }
 140 #endif /* CIFS_NFSD_EXPORT */
 141
 142         return 0;
 143
 144 out_no_root:
 145         cERROR(1, "cifs_read_super: get root inode failed");
 146         if (inode)
 147                 iput(inode);
 148
 149         return rc;
 150 }
 151
 152 static void cifs_kill_sb(struct super_block *sb)
 153 {
 154         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 155         kill_anon_super(sb);
 156         cifs_umount(cifs_sb);
 157 }
 158
 159 static int
 160 cifs_statfs(struct dentry *dentry, struct kstatfs *buf)
 161 {
 162         struct super_block *sb = dentry->d_sb;
 163         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 164         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 165         int rc = -EOPNOTSUPP;
 166         int xid;
 167
 168         xid = GetXid();
 169
 170         buf->f_type = CIFS_MAGIC_NUMBER;
 171
 172         /*
 173          * PATH_MAX may be too long - it would presumably be total path,
 174          * but note that some servers (includinng Samba 3) have a shorter
 175          * maximum path.
 176          *
 177          * Instead could get the real value via SMB_QUERY_FS_ATTRIBUTE_INFO.
 178          */
 179         buf->f_namelen = PATH_MAX;
 180         buf->f_files = 0;       /* undefined */
 181         buf->f_ffree = 0;       /* unlimited */
 182
 183         /*
 184          * We could add a second check for a QFS Unix capability bit
 185          */
 186         if ((tcon->ses->capabilities & CAP_UNIX) &&
 187             (CIFS_POSIX_EXTENSIONS & le64_to_cpu(tcon->fsUnixInfo.Capability)))
 188                 rc = CIFSSMBQFSPosixInfo(xid, tcon, buf);
 189
 190         /*
 191          * Only need to call the old QFSInfo if failed on newer one,
 192          * e.g. by OS/2.
 193          **/
 194         if (rc && (tcon->ses->capabilities & CAP_NT_SMBS))
 195                 rc = CIFSSMBQFSInfo(xid, tcon, buf);
 196
 197         /*
 198          * Some old Windows servers also do not support level 103, retry with
 199          * older level one if old server failed the previous call or we
 200          * bypassed it because we detected that this was an older LANMAN sess
 201          */
 202         if (rc)
 203                 rc = SMBOldQFSInfo(xid, tcon, buf);
 204
 205         FreeXid(xid);
 206         return 0;
 207 }
 208
 209 static int cifs_permission(struct inode *inode, int mask)
 210 {
 211         struct cifs_sb_info *cifs_sb;
 212
 213         cifs_sb = CIFS_SB(inode->i_sb);
 214
 215         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) {
 216                 if ((mask & MAY_EXEC) && !execute_ok(inode))
 217                         return -EACCES;
 218                 else
 219                         return 0;
 220         } else /* file mode might have been restricted at mount time
 221                 on the client (above and beyond ACL on servers) for
 222                 servers which do not support setting and viewing mode bits,
 223                 so allowing client to check permissions is useful */
 224                 return generic_permission(inode, mask);
 225 }
 226
 227 static struct kmem_cache *cifs_inode_cachep;
 228 static struct kmem_cache *cifs_req_cachep;
 229 static struct kmem_cache *cifs_mid_cachep;
 230 static struct kmem_cache *cifs_sm_req_cachep;
 231 mempool_t *cifs_sm_req_poolp;
 232 mempool_t *cifs_req_poolp;
 233 mempool_t *cifs_mid_poolp;
 234
 235 static struct inode *
 236 cifs_alloc_inode(struct super_block *sb)
 237 {
 238         struct cifsInodeInfo *cifs_inode;
 239         cifs_inode = kmem_cache_alloc(cifs_inode_cachep, GFP_KERNEL);
 240         if (!cifs_inode)
 241                 return NULL;
 242         cifs_inode->cifsAttrs = 0x20;   /* default */
 243         cifs_inode->time = 0;
 244         /* Until the file is open and we have gotten oplock
 245         info back from the server, can not assume caching of
 246         file data or metadata */
 247         cifs_set_oplock_level(cifs_inode, 0);
 248         cifs_inode->delete_pending = false;
 249         cifs_inode->invalid_mapping = false;
 250         cifs_inode->vfs_inode.i_blkbits = 14;  /* 2**14 = CIFS_MAX_MSGSIZE */
 251         cifs_inode->server_eof = 0;
 252         cifs_inode->uniqueid = 0;
 253         cifs_inode->createtime = 0;
 254
 255         /* Can not set i_flags here - they get immediately overwritten
 256            to zero by the VFS */
 257 /*      cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME;*/
 258         INIT_LIST_HEAD(&cifs_inode->openFileList);
 259         return &cifs_inode->vfs_inode;
 260 }
 261
 262 static void cifs_i_callback(struct rcu_head *head)
 263 {
 264         struct inode *inode = container_of(head, struct inode, i_rcu);
 265         INIT_LIST_HEAD(&inode->i_dentry);
 266         kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
 267 }
 268
 269 static void
 270 cifs_destroy_inode(struct inode *inode)
 271 {
 272         call_rcu(&inode->i_rcu, cifs_i_callback);
 273 }
 274
 275 static void
 276 cifs_evict_inode(struct inode *inode)
 277 {
 278         truncate_inode_pages(&inode->i_data, 0);
 279         end_writeback(inode);
 280         cifs_fscache_release_inode_cookie(inode);
 281 }
 282
 283 static void
 284 cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
 285 {
 286         struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr;
 287         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr;
 288
 289         seq_printf(s, ",addr=");
 290
 291         switch (server->dstaddr.ss_family) {
 292         case AF_INET:
 293                 seq_printf(s, "%pI4", &sa->sin_addr.s_addr);
 294                 break;
 295         case AF_INET6:
 296                 seq_printf(s, "%pI6", &sa6->sin6_addr.s6_addr);
 297                 if (sa6->sin6_scope_id)
 298                         seq_printf(s, "%%%u", sa6->sin6_scope_id);
 299                 break;
 300         default:
 301                 seq_printf(s, "(unknown)");
 302         }
 303 }
 304
 305 static void
 306 cifs_show_security(struct seq_file *s, struct TCP_Server_Info *server)
 307 {
 308         seq_printf(s, ",sec=");
 309
 310         switch (server->secType) {
 311         case LANMAN:
 312                 seq_printf(s, "lanman");
 313                 break;
 314         case NTLMv2:
 315                 seq_printf(s, "ntlmv2");
 316                 break;
 317         case NTLM:
 318                 seq_printf(s, "ntlm");
 319                 break;
 320         case Kerberos:
 321                 seq_printf(s, "krb5");
 322                 break;
 323         case RawNTLMSSP:
 324                 seq_printf(s, "ntlmssp");
 325                 break;
 326         default:
 327                 /* shouldn't ever happen */
 328                 seq_printf(s, "unknown");
 329                 break;
 330         }
 331
 332         if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 333                 seq_printf(s, "i");
 334 }
 335
 336 /*
 337  * cifs_show_options() is for displaying mount options in /proc/mounts.
 338  * Not all settable options are displayed but most of the important
 339  * ones are.
 340  */
 341 static int
 342 cifs_show_options(struct seq_file *s, struct vfsmount *m)
 343 {
 344         struct cifs_sb_info *cifs_sb = CIFS_SB(m->mnt_sb);
 345         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 346         struct sockaddr *srcaddr;
 347         srcaddr = (struct sockaddr *)&tcon->ses->server->srcaddr;
 348
 349         cifs_show_security(s, tcon->ses->server);
 350
 351         seq_printf(s, ",unc=%s", tcon->treeName);
 352
 353         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)
 354                 seq_printf(s, ",multiuser");
 355         else if (tcon->ses->user_name)
 356                 seq_printf(s, ",username=%s", tcon->ses->user_name);
 357
 358         if (tcon->ses->domainName)
 359                 seq_printf(s, ",domain=%s", tcon->ses->domainName);
 360
 361         if (srcaddr->sa_family != AF_UNSPEC) {
 362                 struct sockaddr_in *saddr4;
 363                 struct sockaddr_in6 *saddr6;
 364                 saddr4 = (struct sockaddr_in *)srcaddr;
 365                 saddr6 = (struct sockaddr_in6 *)srcaddr;
 366                 if (srcaddr->sa_family == AF_INET6)
 367                         seq_printf(s, ",srcaddr=%pI6c",
 368                                    &saddr6->sin6_addr);
 369                 else if (srcaddr->sa_family == AF_INET)
 370                         seq_printf(s, ",srcaddr=%pI4",
 371                                    &saddr4->sin_addr.s_addr);
 372                 else
 373                         seq_printf(s, ",srcaddr=BAD-AF:%i",
 374                                    (int)(srcaddr->sa_family));
 375         }
 376
 377         seq_printf(s, ",uid=%d", cifs_sb->mnt_uid);
 378         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
 379                 seq_printf(s, ",forceuid");
 380         else
 381                 seq_printf(s, ",noforceuid");
 382
 383         seq_printf(s, ",gid=%d", cifs_sb->mnt_gid);
 384         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
 385                 seq_printf(s, ",forcegid");
 386         else
 387                 seq_printf(s, ",noforcegid");
 388
 389         cifs_show_address(s, tcon->ses->server);
 390
 391         if (!tcon->unix_ext)
 392                 seq_printf(s, ",file_mode=0%o,dir_mode=0%o",
 393                                            cifs_sb->mnt_file_mode,
 394                                            cifs_sb->mnt_dir_mode);
 395         if (tcon->seal)
 396                 seq_printf(s, ",seal");
 397         if (tcon->nocase)
 398                 seq_printf(s, ",nocase");
 399         if (tcon->retry)
 400                 seq_printf(s, ",hard");
 401         if (tcon->unix_ext)
 402                 seq_printf(s, ",unix");
 403         else
 404                 seq_printf(s, ",nounix");
 405         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
 406                 seq_printf(s, ",posixpaths");
 407         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)
 408                 seq_printf(s, ",setuids");
 409         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
 410                 seq_printf(s, ",serverino");
 411         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
 412                 seq_printf(s, ",rwpidforward");
 413         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL)
 414                 seq_printf(s, ",forcemand");
 415         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO)
 416                 seq_printf(s, ",directio");
 417         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
 418                 seq_printf(s, ",nouser_xattr");
 419         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
 420                 seq_printf(s, ",mapchars");
 421         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)
 422                 seq_printf(s, ",sfu");
 423         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 424                 seq_printf(s, ",nobrl");
 425         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
 426                 seq_printf(s, ",cifsacl");
 427         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 428                 seq_printf(s, ",dynperm");
 429         if (m->mnt_sb->s_flags & MS_POSIXACL)
 430                 seq_printf(s, ",acl");
 431         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
 432                 seq_printf(s, ",mfsymlinks");
 433         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
 434                 seq_printf(s, ",fsc");
 435
 436         seq_printf(s, ",rsize=%d", cifs_sb->rsize);
 437         seq_printf(s, ",wsize=%d", cifs_sb->wsize);
 438         /* convert actimeo and display it in seconds */
 439                 seq_printf(s, ",actimeo=%lu", cifs_sb->actimeo / HZ);
 440
 441         return 0;
 442 }
 443
 444 static void cifs_umount_begin(struct super_block *sb)
 445 {
 446         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 447         struct cifs_tcon *tcon;
 448
 449         if (cifs_sb == NULL)
 450                 return;
 451
 452         tcon = cifs_sb_master_tcon(cifs_sb);
 453
 454         spin_lock(&cifs_tcp_ses_lock);
 455         if ((tcon->tc_count > 1) || (tcon->tidStatus == CifsExiting)) {
 456                 /* we have other mounts to same share or we have
 457                    already tried to force umount this and woken up
 458                    all waiting network requests, nothing to do */
 459                 spin_unlock(&cifs_tcp_ses_lock);
 460                 return;
 461         } else if (tcon->tc_count == 1)
 462                 tcon->tidStatus = CifsExiting;
 463         spin_unlock(&cifs_tcp_ses_lock);
 464
 465         /* cancel_brl_requests(tcon); */ /* BB mark all brl mids as exiting */
 466         /* cancel_notify_requests(tcon); */
 467         if (tcon->ses && tcon->ses->server) {
 468                 cFYI(1, "wake up tasks now - umount begin not complete");
 469                 wake_up_all(&tcon->ses->server->request_q);
 470                 wake_up_all(&tcon->ses->server->response_q);
 471                 msleep(1); /* yield */
 472                 /* we have to kick the requests once more */
 473                 wake_up_all(&tcon->ses->server->response_q);
 474                 msleep(1);
 475         }
 476
 477         return;
 478 }
 479
 480 #ifdef CONFIG_CIFS_STATS2
 481 static int cifs_show_stats(struct seq_file *s, struct vfsmount *mnt)
 482 {
 483         /* BB FIXME */
 484         return 0;
 485 }
 486 #endif
 487
 488 static int cifs_remount(struct super_block *sb, int *flags, char *data)
 489 {
 490         *flags |= MS_NODIRATIME;
 491         return 0;
 492 }
 493
 494 static int cifs_drop_inode(struct inode *inode)
 495 {
 496         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 497
 498         /* no serverino => unconditional eviction */
 499         return !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) ||
 500                 generic_drop_inode(inode);
 501 }
 502
 503 static const struct super_operations cifs_super_ops = {
 504         .statfs = cifs_statfs,
 505         .alloc_inode = cifs_alloc_inode,
 506         .destroy_inode = cifs_destroy_inode,
 507         .drop_inode     = cifs_drop_inode,
 508         .evict_inode    = cifs_evict_inode,
 509 /*      .delete_inode   = cifs_delete_inode,  */  /* Do not need above
 510         function unless later we add lazy close of inodes or unless the
 511         kernel forgets to call us with the same number of releases (closes)
 512         as opens */
 513         .show_options = cifs_show_options,
 514         .umount_begin   = cifs_umount_begin,
 515         .remount_fs = cifs_remount,
 516 #ifdef CONFIG_CIFS_STATS2
 517         .show_stats = cifs_show_stats,
 518 #endif
 519 };
 520
 521 /*
 522  * Get root dentry from superblock according to prefix path mount option.
 523  * Return dentry with refcount + 1 on success and NULL otherwise.
 524  */
 525 static struct dentry *
 526 cifs_get_root(struct smb_vol *vol, struct super_block *sb)
 527 {
 528         struct dentry *dentry;
 529         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 530         char *full_path = NULL;
 531         char *s, *p;
 532         char sep;
 533         int xid;
 534
 535         full_path = cifs_build_path_to_root(vol, cifs_sb,
 536                                             cifs_sb_master_tcon(cifs_sb));
 537         if (full_path == NULL)
 538                 return ERR_PTR(-ENOMEM);
 539
 540         cFYI(1, "Get root dentry for %s", full_path);
 541
 542         xid = GetXid();
 543         sep = CIFS_DIR_SEP(cifs_sb);
 544         dentry = dget(sb->s_root);
 545         p = s = full_path;
 546
 547         do {
 548                 struct inode *dir = dentry->d_inode;
 549                 struct dentry *child;
 550
 551                 /* skip separators */
 552                 while (*s == sep)
 553                         s++;
 554                 if (!*s)
 555                         break;
 556                 p = s++;
 557                 /* next separator */
 558                 while (*s && *s != sep)
 559                         s++;
 560
 561                 mutex_lock(&dir->i_mutex);
 562                 child = lookup_one_len(p, dentry, s - p);
 563                 mutex_unlock(&dir->i_mutex);
 564                 dput(dentry);
 565                 dentry = child;
 566                 if (!dentry->d_inode) {
 567                         dput(dentry);
 568                         dentry = ERR_PTR(-ENOENT);
 569                 }
 570         } while (!IS_ERR(dentry));
 571         _FreeXid(xid);
 572         kfree(full_path);
 573         return dentry;
 574 }
 575
 576 static int cifs_set_super(struct super_block *sb, void *data)
 577 {
 578         struct cifs_mnt_data *mnt_data = data;
 579         sb->s_fs_info = mnt_data->cifs_sb;
 580         return set_anon_super(sb, NULL);
 581 }
 582
 583 static struct dentry *
 584 cifs_do_mount(struct file_system_type *fs_type,
 585               int flags, const char *dev_name, void *data)
 586 {
 587         int rc;
 588         struct super_block *sb;
 589         struct cifs_sb_info *cifs_sb;
 590         struct smb_vol *volume_info;
 591         struct cifs_mnt_data mnt_data;
 592         struct dentry *root;
 593
 594         cFYI(1, "Devname: %s flags: %d ", dev_name, flags);
 595
 596         volume_info = cifs_get_volume_info((char *)data, dev_name);
 597         if (IS_ERR(volume_info))
 598                 return ERR_CAST(volume_info);
 599
 600         cifs_sb = kzalloc(sizeof(struct cifs_sb_info), GFP_KERNEL);
 601         if (cifs_sb == NULL) {
 602                 root = ERR_PTR(-ENOMEM);
 603                 goto out_nls;
 604         }
 605
 606         cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
 607         if (cifs_sb->mountdata == NULL) {
 608                 root = ERR_PTR(-ENOMEM);
 609                 goto out_cifs_sb;
 610         }
 611
 612         cifs_setup_cifs_sb(volume_info, cifs_sb);
 613
 614         rc = cifs_mount(cifs_sb, volume_info);
 615         if (rc) {
 616                 if (!(flags & MS_SILENT))
 617                         cERROR(1, "cifs_mount failed w/return code = %d", rc);
 618                 root = ERR_PTR(rc);
 619                 goto out_mountdata;
 620         }
 621
 622         mnt_data.vol = volume_info;
 623         mnt_data.cifs_sb = cifs_sb;
 624         mnt_data.flags = flags;
 625
 626         sb = sget(fs_type, cifs_match_super, cifs_set_super, &mnt_data);
 627         if (IS_ERR(sb)) {
 628                 root = ERR_CAST(sb);
 629                 cifs_umount(cifs_sb);
 630                 goto out;
 631         }
 632
 633         if (sb->s_root) {
 634                 cFYI(1, "Use existing superblock");
 635                 cifs_umount(cifs_sb);
 636         } else {
 637                 sb->s_flags = flags;
 638                 /* BB should we make this contingent on mount parm? */
 639                 sb->s_flags |= MS_NODIRATIME | MS_NOATIME;
 640
 641                 rc = cifs_read_super(sb);
 642                 if (rc) {
 643                         root = ERR_PTR(rc);
 644                         goto out_super;
 645                 }
 646
 647                 sb->s_flags |= MS_ACTIVE;
 648         }
 649
 650         root = cifs_get_root(volume_info, sb);
 651         if (IS_ERR(root))
 652                 goto out_super;
 653
 654         cFYI(1, "dentry root is: %p", root);
 655         goto out;
 656
 657 out_super:
 658         deactivate_locked_super(sb);
 659 out:
 660         cifs_cleanup_volume_info(volume_info);
 661         return root;
 662
 663 out_mountdata:
 664         kfree(cifs_sb->mountdata);
 665 out_cifs_sb:
 666         kfree(cifs_sb);
 667 out_nls:
 668         unload_nls(volume_info->local_nls);
 669         goto out;
 670 }
 671
 672 static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 673                                    unsigned long nr_segs, loff_t pos)
 674 {
 675         struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 676         ssize_t written;
 677         int rc;
 678
 679         written = generic_file_aio_write(iocb, iov, nr_segs, pos);
 680
 681         if (CIFS_I(inode)->clientCanCacheAll)
 682                 return written;
 683
 684         rc = filemap_fdatawrite(inode->i_mapping);
 685         if (rc)
 686                 cFYI(1, "cifs_file_aio_write: %d rc on %p inode", rc, inode);
 687
 688         return written;
 689 }
 690
 691 static loff_t cifs_llseek(struct file *file, loff_t offset, int origin)
 692 {
 693         /*
 694          * origin == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
 695          * the cached file length
 696          */
 697         if (origin != SEEK_SET || origin != SEEK_CUR) {
 698                 int rc;
 699                 struct inode *inode = file->f_path.dentry->d_inode;
 700
 701                 /*
 702                  * We need to be sure that all dirty pages are written and the
 703                  * server has the newest file length.
 704                  */
 705                 if (!CIFS_I(inode)->clientCanCacheRead && inode->i_mapping &&
 706                     inode->i_mapping->nrpages != 0) {
 707                         rc = filemap_fdatawait(inode->i_mapping);
 708                         if (rc) {
 709                                 mapping_set_error(inode->i_mapping, rc);
 710                                 return rc;
 711                         }
 712                 }
 713                 /*
 714                  * Some applications poll for the file length in this strange
 715                  * way so we must seek to end on non-oplocked files by
 716                  * setting the revalidate time to zero.
 717                  */
 718                 CIFS_I(inode)->time = 0;
 719
 720                 rc = cifs_revalidate_file_attr(file);
 721                 if (rc < 0)
 722                         return (loff_t)rc;
 723         }
 724         return generic_file_llseek_unlocked(file, offset, origin);
 725 }
 726
 727 static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
 728 {
 729         /* note that this is called by vfs setlease with lock_flocks held
 730            to protect *lease from going away */
 731         struct inode *inode = file->f_path.dentry->d_inode;
 732         struct cifsFileInfo *cfile = file->private_data;
 733
 734         if (!(S_ISREG(inode->i_mode)))
 735                 return -EINVAL;
 736
 737         /* check if file is oplocked */
 738         if (((arg == F_RDLCK) &&
 739                 (CIFS_I(inode)->clientCanCacheRead)) ||
 740             ((arg == F_WRLCK) &&
 741                 (CIFS_I(inode)->clientCanCacheAll)))
 742                 return generic_setlease(file, arg, lease);
 743         else if (tlink_tcon(cfile->tlink)->local_lease &&
 744                  !CIFS_I(inode)->clientCanCacheRead)
 745                 /* If the server claims to support oplock on this
 746                    file, then we still need to check oplock even
 747                    if the local_lease mount option is set, but there
 748                    are servers which do not support oplock for which
 749                    this mount option may be useful if the user
 750                    knows that the file won't be changed on the server
 751                    by anyone else */
 752                 return generic_setlease(file, arg, lease);
 753         else
 754                 return -EAGAIN;
 755 }
 756
 757 struct file_system_type cifs_fs_type = {
 758         .owner = THIS_MODULE,
 759         .name = "cifs",
 760         .mount = cifs_do_mount,
 761         .kill_sb = cifs_kill_sb,
 762         /*  .fs_flags */
 763 };
 764 const struct inode_operations cifs_dir_inode_ops = {
 765         .create = cifs_create,
 766         .lookup = cifs_lookup,
 767         .getattr = cifs_getattr,
 768         .unlink = cifs_unlink,
 769         .link = cifs_hardlink,
 770         .mkdir = cifs_mkdir,
 771         .rmdir = cifs_rmdir,
 772         .rename = cifs_rename,
 773         .permission = cifs_permission,
 774 /*      revalidate:cifs_revalidate,   */
 775         .setattr = cifs_setattr,
 776         .symlink = cifs_symlink,
 777         .mknod   = cifs_mknod,
 778 #ifdef CONFIG_CIFS_XATTR
 779         .setxattr = cifs_setxattr,
 780         .getxattr = cifs_getxattr,
 781         .listxattr = cifs_listxattr,
 782         .removexattr = cifs_removexattr,
 783 #endif
 784 };
 785
 786 const struct inode_operations cifs_file_inode_ops = {
 787 /*      revalidate:cifs_revalidate, */
 788         .setattr = cifs_setattr,
 789         .getattr = cifs_getattr, /* do we need this anymore? */
 790         .rename = cifs_rename,
 791         .permission = cifs_permission,
 792 #ifdef CONFIG_CIFS_XATTR
 793         .setxattr = cifs_setxattr,
 794         .getxattr = cifs_getxattr,
 795         .listxattr = cifs_listxattr,
 796         .removexattr = cifs_removexattr,
 797 #endif
 798 };
 799
 800 const struct inode_operations cifs_symlink_inode_ops = {
 801         .readlink = generic_readlink,
 802         .follow_link = cifs_follow_link,
 803         .put_link = cifs_put_link,
 804         .permission = cifs_permission,
 805         /* BB add the following two eventually */
 806         /* revalidate: cifs_revalidate,
 807            setattr:    cifs_notify_change, *//* BB do we need notify change */
 808 #ifdef CONFIG_CIFS_XATTR
 809         .setxattr = cifs_setxattr,
 810         .getxattr = cifs_getxattr,
 811         .listxattr = cifs_listxattr,
 812         .removexattr = cifs_removexattr,
 813 #endif
 814 };
 815
 816 const struct file_operations cifs_file_ops = {
 817         .read = do_sync_read,
 818         .write = do_sync_write,
 819         .aio_read = generic_file_aio_read,
 820         .aio_write = cifs_file_aio_write,
 821         .open = cifs_open,
 822         .release = cifs_close,
 823         .lock = cifs_lock,
 824         .fsync = cifs_fsync,
 825         .flush = cifs_flush,
 826         .mmap  = cifs_file_mmap,
 827         .splice_read = generic_file_splice_read,
 828         .llseek = cifs_llseek,
 829 #ifdef CONFIG_CIFS_POSIX
 830         .unlocked_ioctl = cifs_ioctl,
 831 #endif /* CONFIG_CIFS_POSIX */
 832         .setlease = cifs_setlease,
 833 };
 834
 835 const struct file_operations cifs_file_strict_ops = {
 836         .read = do_sync_read,
 837         .write = do_sync_write,
 838         .aio_read = cifs_strict_readv,
 839         .aio_write = cifs_strict_writev,
 840         .open = cifs_open,
 841         .release = cifs_close,
 842         .lock = cifs_lock,
 843         .fsync = cifs_strict_fsync,
 844         .flush = cifs_flush,
 845         .mmap = cifs_file_strict_mmap,
 846         .splice_read = generic_file_splice_read,
 847         .llseek = cifs_llseek,
 848 #ifdef CONFIG_CIFS_POSIX
 849         .unlocked_ioctl = cifs_ioctl,
 850 #endif /* CONFIG_CIFS_POSIX */
 851         .setlease = cifs_setlease,
 852 };
 853
 854 const struct file_operations cifs_file_direct_ops = {
 855         /* BB reevaluate whether they can be done with directio, no cache */
 856         .read = do_sync_read,
 857         .write = do_sync_write,
 858         .aio_read = cifs_user_readv,
 859         .aio_write = cifs_user_writev,
 860         .open = cifs_open,
 861         .release = cifs_close,
 862         .lock = cifs_lock,
 863         .fsync = cifs_fsync,
 864         .flush = cifs_flush,
 865         .mmap = cifs_file_mmap,
 866         .splice_read = generic_file_splice_read,
 867 #ifdef CONFIG_CIFS_POSIX
 868         .unlocked_ioctl  = cifs_ioctl,
 869 #endif /* CONFIG_CIFS_POSIX */
 870         .llseek = cifs_llseek,
 871         .setlease = cifs_setlease,
 872 };
 873
 874 const struct file_operations cifs_file_nobrl_ops = {
 875         .read = do_sync_read,
 876         .write = do_sync_write,
 877         .aio_read = generic_file_aio_read,
 878         .aio_write = cifs_file_aio_write,
 879         .open = cifs_open,
 880         .release = cifs_close,
 881         .fsync = cifs_fsync,
 882         .flush = cifs_flush,
 883         .mmap  = cifs_file_mmap,
 884         .splice_read = generic_file_splice_read,
 885         .llseek = cifs_llseek,
 886 #ifdef CONFIG_CIFS_POSIX
 887         .unlocked_ioctl = cifs_ioctl,
 888 #endif /* CONFIG_CIFS_POSIX */
 889         .setlease = cifs_setlease,
 890 };
 891
 892 const struct file_operations cifs_file_strict_nobrl_ops = {
 893         .read = do_sync_read,
 894         .write = do_sync_write,
 895         .aio_read = cifs_strict_readv,
 896         .aio_write = cifs_strict_writev,
 897         .open = cifs_open,
 898         .release = cifs_close,
 899         .fsync = cifs_strict_fsync,
 900         .flush = cifs_flush,
 901         .mmap = cifs_file_strict_mmap,
 902         .splice_read = generic_file_splice_read,
 903         .llseek = cifs_llseek,
 904 #ifdef CONFIG_CIFS_POSIX
 905         .unlocked_ioctl = cifs_ioctl,
 906 #endif /* CONFIG_CIFS_POSIX */
 907         .setlease = cifs_setlease,
 908 };
 909
 910 const struct file_operations cifs_file_direct_nobrl_ops = {
 911         /* BB reevaluate whether they can be done with directio, no cache */
 912         .read = do_sync_read,
 913         .write = do_sync_write,
 914         .aio_read = cifs_user_readv,
 915         .aio_write = cifs_user_writev,
 916         .open = cifs_open,
 917         .release = cifs_close,
 918         .fsync = cifs_fsync,
 919         .flush = cifs_flush,
 920         .mmap = cifs_file_mmap,
 921         .splice_read = generic_file_splice_read,
 922 #ifdef CONFIG_CIFS_POSIX
 923         .unlocked_ioctl  = cifs_ioctl,
 924 #endif /* CONFIG_CIFS_POSIX */
 925         .llseek = cifs_llseek,
 926         .setlease = cifs_setlease,
 927 };
 928
 929 const struct file_operations cifs_dir_ops = {
 930         .readdir = cifs_readdir,
 931         .release = cifs_closedir,
 932         .read    = generic_read_dir,
 933         .unlocked_ioctl  = cifs_ioctl,
 934         .llseek = generic_file_llseek,
 935 };
 936
 937 static void
 938 cifs_init_once(void *inode)
 939 {
 940         struct cifsInodeInfo *cifsi = inode;
 941
 942         inode_init_once(&cifsi->vfs_inode);
 943         INIT_LIST_HEAD(&cifsi->lockList);
 944 }
 945
 946 static int
 947 cifs_init_inodecache(void)
 948 {
 949         cifs_inode_cachep = kmem_cache_create("cifs_inode_cache",
 950                                               sizeof(struct cifsInodeInfo),
 951                                               0, (SLAB_RECLAIM_ACCOUNT|
 952                                                 SLAB_MEM_SPREAD),
 953                                               cifs_init_once);
 954         if (cifs_inode_cachep == NULL)
 955                 return -ENOMEM;
 956
 957         return 0;
 958 }
 959
 960 static void
 961 cifs_destroy_inodecache(void)
 962 {
 963         kmem_cache_destroy(cifs_inode_cachep);
 964 }
 965
 966 static int
 967 cifs_init_request_bufs(void)
 968 {
 969         if (CIFSMaxBufSize < 8192) {
 970         /* Buffer size can not be smaller than 2 * PATH_MAX since maximum
 971         Unicode path name has to fit in any SMB/CIFS path based frames */
 972                 CIFSMaxBufSize = 8192;
 973         } else if (CIFSMaxBufSize > 1024*127) {
 974                 CIFSMaxBufSize = 1024 * 127;
 975         } else {
 976                 CIFSMaxBufSize &= 0x1FE00; /* Round size to even 512 byte mult*/
 977         }
 978 /*      cERROR(1, "CIFSMaxBufSize %d 0x%x",CIFSMaxBufSize,CIFSMaxBufSize); */
 979         cifs_req_cachep = kmem_cache_create("cifs_request",
 980                                             CIFSMaxBufSize +
 981                                             MAX_CIFS_HDR_SIZE, 0,
 982                                             SLAB_HWCACHE_ALIGN, NULL);
 983         if (cifs_req_cachep == NULL)
 984                 return -ENOMEM;
 985
 986         if (cifs_min_rcv < 1)
 987                 cifs_min_rcv = 1;
 988         else if (cifs_min_rcv > 64) {
 989                 cifs_min_rcv = 64;
 990                 cERROR(1, "cifs_min_rcv set to maximum (64)");
 991         }
 992
 993         cifs_req_poolp = mempool_create_slab_pool(cifs_min_rcv,
 994                                                   cifs_req_cachep);
 995
 996         if (cifs_req_poolp == NULL) {
 997                 kmem_cache_destroy(cifs_req_cachep);
 998                 return -ENOMEM;
 999         }
1000         /* MAX_CIFS_SMALL_BUFFER_SIZE bytes is enough for most SMB responses and
1001         almost all handle based requests (but not write response, nor is it
1002         sufficient for path based requests).  A smaller size would have
1003         been more efficient (compacting multiple slab items on one 4k page)
1004         for the case in which debug was on, but this larger size allows
1005         more SMBs to use small buffer alloc and is still much more
1006         efficient to alloc 1 per page off the slab compared to 17K (5page)
1007         alloc of large cifs buffers even when page debugging is on */
1008         cifs_sm_req_cachep = kmem_cache_create("cifs_small_rq",
1009                         MAX_CIFS_SMALL_BUFFER_SIZE, 0, SLAB_HWCACHE_ALIGN,
1010                         NULL);
1011         if (cifs_sm_req_cachep == NULL) {
1012                 mempool_destroy(cifs_req_poolp);
1013                 kmem_cache_destroy(cifs_req_cachep);
1014                 return -ENOMEM;
1015         }
1016
1017         if (cifs_min_small < 2)
1018                 cifs_min_small = 2;
1019         else if (cifs_min_small > 256) {
1020                 cifs_min_small = 256;
1021                 cFYI(1, "cifs_min_small set to maximum (256)");
1022         }
1023
1024         cifs_sm_req_poolp = mempool_create_slab_pool(cifs_min_small,
1025                                                      cifs_sm_req_cachep);
1026
1027         if (cifs_sm_req_poolp == NULL) {
1028                 mempool_destroy(cifs_req_poolp);
1029                 kmem_cache_destroy(cifs_req_cachep);
1030                 kmem_cache_destroy(cifs_sm_req_cachep);
1031                 return -ENOMEM;
1032         }
1033
1034         return 0;
1035 }
1036
1037 static void
1038 cifs_destroy_request_bufs(void)
1039 {
1040         mempool_destroy(cifs_req_poolp);
1041         kmem_cache_destroy(cifs_req_cachep);
1042         mempool_destroy(cifs_sm_req_poolp);
1043         kmem_cache_destroy(cifs_sm_req_cachep);
1044 }
1045
1046 static int
1047 cifs_init_mids(void)
1048 {
1049         cifs_mid_cachep = kmem_cache_create("cifs_mpx_ids",
1050                                             sizeof(struct mid_q_entry), 0,
1051                                             SLAB_HWCACHE_ALIGN, NULL);
1052         if (cifs_mid_cachep == NULL)
1053                 return -ENOMEM;
1054
1055         /* 3 is a reasonable minimum number of simultaneous operations */
1056         cifs_mid_poolp = mempool_create_slab_pool(3, cifs_mid_cachep);
1057         if (cifs_mid_poolp == NULL) {
1058                 kmem_cache_destroy(cifs_mid_cachep);
1059                 return -ENOMEM;
1060         }
1061
1062         return 0;
1063 }
1064
1065 static void
1066 cifs_destroy_mids(void)
1067 {
1068         mempool_destroy(cifs_mid_poolp);
1069         kmem_cache_destroy(cifs_mid_cachep);
1070 }
1071
1072 static int __init
1073 init_cifs(void)
1074 {
1075         int rc = 0;
1076         cifs_proc_init();
1077         INIT_LIST_HEAD(&cifs_tcp_ses_list);
1078 #ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
1079         INIT_LIST_HEAD(&GlobalDnotifyReqList);
1080         INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
1081 #endif /* was needed for dnotify, and will be needed for inotify when VFS fix */
1082 /*
1083  *  Initialize Global counters
1084  */
1085         atomic_set(&sesInfoAllocCount, 0);
1086         atomic_set(&tconInfoAllocCount, 0);
1087         atomic_set(&tcpSesAllocCount, 0);
1088         atomic_set(&tcpSesReconnectCount, 0);
1089         atomic_set(&tconInfoReconnectCount, 0);
1090
1091         atomic_set(&bufAllocCount, 0);
1092         atomic_set(&smBufAllocCount, 0);
1093 #ifdef CONFIG_CIFS_STATS2
1094         atomic_set(&totBufAllocCount, 0);
1095         atomic_set(&totSmBufAllocCount, 0);
1096 #endif /* CONFIG_CIFS_STATS2 */
1097
1098         atomic_set(&midCount, 0);
1099         GlobalCurrentXid = 0;
1100         GlobalTotalActiveXid = 0;
1101         GlobalMaxActiveXid = 0;
1102         spin_lock_init(&cifs_tcp_ses_lock);
1103         spin_lock_init(&cifs_file_list_lock);
1104         spin_lock_init(&GlobalMid_Lock);
1105
1106         if (cifs_max_pending < 2) {
1107                 cifs_max_pending = 2;
1108                 cFYI(1, "cifs_max_pending set to min of 2");
1109         } else if (cifs_max_pending > 256) {
1110                 cifs_max_pending = 256;
1111                 cFYI(1, "cifs_max_pending set to max of 256");
1112         }
1113
1114         rc = cifs_fscache_register();
1115         if (rc)
1116                 goto out_clean_proc;
1117
1118         rc = cifs_init_inodecache();
1119         if (rc)
1120                 goto out_unreg_fscache;
1121
1122         rc = cifs_init_mids();
1123         if (rc)
1124                 goto out_destroy_inodecache;
1125
1126         rc = cifs_init_request_bufs();
1127         if (rc)
1128                 goto out_destroy_mids;
1129
1130 #ifdef CONFIG_CIFS_UPCALL
1131         rc = register_key_type(&cifs_spnego_key_type);
1132         if (rc)
1133                 goto out_destroy_request_bufs;
1134 #endif /* CONFIG_CIFS_UPCALL */
1135
1136 #ifdef CONFIG_CIFS_ACL
1137         rc = init_cifs_idmap();
1138         if (rc)
1139                 goto out_register_key_type;
1140 #endif /* CONFIG_CIFS_ACL */
1141
1142         rc = register_filesystem(&cifs_fs_type);
1143         if (rc)
1144                 goto out_init_cifs_idmap;
1145
1146         return 0;
1147
1148 out_init_cifs_idmap:
1149 #ifdef CONFIG_CIFS_ACL
1150         exit_cifs_idmap();
1151 out_register_key_type:
1152 #endif
1153 #ifdef CONFIG_CIFS_UPCALL
1154         unregister_key_type(&cifs_spnego_key_type);
1155 out_destroy_request_bufs:
1156 #endif
1157         cifs_destroy_request_bufs();
1158 out_destroy_mids:
1159         cifs_destroy_mids();
1160 out_destroy_inodecache:
1161         cifs_destroy_inodecache();
1162 out_unreg_fscache:
1163         cifs_fscache_unregister();
1164 out_clean_proc:
1165         cifs_proc_clean();
1166         return rc;
1167 }
1168
1169 static void __exit
1170 exit_cifs(void)
1171 {
1172         cFYI(DBG2, "exit_cifs");
1173         cifs_proc_clean();
1174         cifs_fscache_unregister();
1175 #ifdef CONFIG_CIFS_DFS_UPCALL
1176         cifs_dfs_release_automount_timer();
1177 #endif
1178 #ifdef CONFIG_CIFS_ACL
1179         cifs_destroy_idmaptrees();
1180         exit_cifs_idmap();
1181 #endif
1182 #ifdef CONFIG_CIFS_UPCALL
1183         unregister_key_type(&cifs_spnego_key_type);
1184 #endif
1185         unregister_filesystem(&cifs_fs_type);
1186         cifs_destroy_inodecache();
1187         cifs_destroy_mids();
1188         cifs_destroy_request_bufs();
1189 }
1190
1191 MODULE_AUTHOR("Steve French <sfrench@us.ibm.com>");
1192 MODULE_LICENSE("GPL");  /* combination of LGPL + GPL source behaves as GPL */
1193 MODULE_DESCRIPTION
1194     ("VFS to access servers complying with the SNIA CIFS Specification "
1195      "e.g. Samba and Windows");
1196 MODULE_VERSION(CIFS_VERSION);
1197 module_init(init_cifs)
1198 module_exit(exit_cifs)