fs/smb/client/ioctl.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   vfs operations that deal with io control
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2005,2013
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  */
  10
  11 #include <linux/fs.h>
  12 #include <linux/file.h>
  13 #include <linux/mount.h>
  14 #include <linux/mm.h>
  15 #include <linux/pagemap.h>
  16 #include "cifspdu.h"
  17 #include "cifsglob.h"
  18 #include "cifsproto.h"
  19 #include "cifs_debug.h"
  20 #include "cifsfs.h"
  21 #include "cifs_ioctl.h"
  22 #include "smb2proto.h"
  23 #include "smb2glob.h"
  24 #include <linux/btrfs.h>
  25
  26 static long cifs_ioctl_query_info(unsigned int xid, struct file *filep,
  27                                   unsigned long p)
  28 {
  29         struct inode *inode = file_inode(filep);
  30         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
  31         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  32         struct dentry *dentry = filep->f_path.dentry;
  33         const unsigned char *path;
  34         void *page = alloc_dentry_path();
  35         __le16 *utf16_path = NULL, root_path;
  36         int rc = 0;
  37
  38         path = build_path_from_dentry(dentry, page);
  39         if (IS_ERR(path)) {
  40                 free_dentry_path(page);
  41                 return PTR_ERR(path);
  42         }
  43
  44         cifs_dbg(FYI, "%s %s\n", __func__, path);
  45
  46         if (!path[0]) {
  47                 root_path = 0;
  48                 utf16_path = &root_path;
  49         } else {
  50                 utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
  51                 if (!utf16_path) {
  52                         rc = -ENOMEM;
  53                         goto ici_exit;
  54                 }
  55         }
  56
  57         if (tcon->ses->server->ops->ioctl_query_info)
  58                 rc = tcon->ses->server->ops->ioctl_query_info(
  59                                 xid, tcon, cifs_sb, utf16_path,
  60                                 filep->private_data ? 0 : 1, p);
  61         else
  62                 rc = -EOPNOTSUPP;
  63
  64  ici_exit:
  65         if (utf16_path != &root_path)
  66                 kfree(utf16_path);
  67         free_dentry_path(page);
  68         return rc;
  69 }
  70
  71 static long cifs_ioctl_copychunk(unsigned int xid, struct file *dst_file,
  72                         unsigned long srcfd)
  73 {
  74         int rc;
  75         struct inode *src_inode;
  76
  77         cifs_dbg(FYI, "ioctl copychunk range\n");
  78         /* the destination must be opened for writing */
  79         if (!(dst_file->f_mode & FMODE_WRITE)) {
  80                 cifs_dbg(FYI, "file target not open for write\n");
  81                 return -EINVAL;
  82         }
  83
  84         /* check if target volume is readonly and take reference */
  85         rc = mnt_want_write_file(dst_file);
  86         if (rc) {
  87                 cifs_dbg(FYI, "mnt_want_write failed with rc %d\n", rc);
  88                 return rc;
  89         }
  90
  91         CLASS(fd, src_file)(srcfd);
  92         if (fd_empty(src_file)) {
  93                 rc = -EBADF;
  94                 goto out_drop_write;
  95         }
  96
  97         if (fd_file(src_file)->f_op->unlocked_ioctl != cifs_ioctl) {
  98                 rc = -EBADF;
  99                 cifs_dbg(VFS, "src file seems to be from a different filesystem type\n");
 100                 goto out_drop_write;
 101         }
 102
 103         src_inode = file_inode(fd_file(src_file));
 104         rc = -EINVAL;
 105         if (S_ISDIR(src_inode->i_mode))
 106                 goto out_drop_write;
 107
 108         rc = cifs_file_copychunk_range(xid, fd_file(src_file), 0, dst_file, 0,
 109                                         src_inode->i_size, 0);
 110         if (rc > 0)
 111                 rc = 0;
 112 out_drop_write:
 113         mnt_drop_write_file(dst_file);
 114         return rc;
 115 }
 116
 117 static long smb_mnt_get_tcon_info(struct cifs_tcon *tcon, void __user *arg)
 118 {
 119         int rc = 0;
 120         struct smb_mnt_tcon_info tcon_inf;
 121
 122         tcon_inf.tid = tcon->tid;
 123         tcon_inf.session_id = tcon->ses->Suid;
 124
 125         if (copy_to_user(arg, &tcon_inf, sizeof(struct smb_mnt_tcon_info)))
 126                 rc = -EFAULT;
 127
 128         return rc;
 129 }
 130
 131 static long smb_mnt_get_fsinfo(unsigned int xid, struct cifs_tcon *tcon,
 132                                 void __user *arg)
 133 {
 134         int rc = 0;
 135         struct smb_mnt_fs_info *fsinf;
 136
 137         fsinf = kzalloc(sizeof(struct smb_mnt_fs_info), GFP_KERNEL);
 138         if (fsinf == NULL)
 139                 return -ENOMEM;
 140
 141         fsinf->version = 1;
 142         fsinf->protocol_id = tcon->ses->server->vals->protocol_id;
 143         fsinf->tcon_flags = tcon->Flags;
 144         fsinf->device_characteristics =
 145                         le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics);
 146         fsinf->device_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
 147         fsinf->fs_attributes = le32_to_cpu(tcon->fsAttrInfo.Attributes);
 148         fsinf->max_path_component =
 149                 le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength);
 150         fsinf->vol_serial_number = tcon->vol_serial_number;
 151         fsinf->vol_create_time = le64_to_cpu(tcon->vol_create_time);
 152         fsinf->share_flags = tcon->share_flags;
 153         fsinf->share_caps = le32_to_cpu(tcon->capabilities);
 154         fsinf->sector_flags = tcon->ss_flags;
 155         fsinf->optimal_sector_size = tcon->perf_sector_size;
 156         fsinf->max_bytes_chunk = tcon->max_bytes_chunk;
 157         fsinf->maximal_access = tcon->maximal_access;
 158         fsinf->cifs_posix_caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 159
 160         if (copy_to_user(arg, fsinf, sizeof(struct smb_mnt_fs_info)))
 161                 rc = -EFAULT;
 162
 163         kfree(fsinf);
 164         return rc;
 165 }
 166
 167 static int cifs_shutdown(struct super_block *sb, unsigned long arg)
 168 {
 169         struct cifs_sb_info *sbi = CIFS_SB(sb);
 170         struct tcon_link *tlink;
 171         struct cifs_tcon *tcon;
 172         __u32 flags;
 173         int rc;
 174
 175         if (!capable(CAP_SYS_ADMIN))
 176                 return -EPERM;
 177
 178         if (get_user(flags, (__u32 __user *)arg))
 179                 return -EFAULT;
 180
 181         tlink = cifs_sb_tlink(sbi);
 182         if (IS_ERR(tlink))
 183                 return PTR_ERR(tlink);
 184         tcon = tlink_tcon(tlink);
 185
 186         trace_smb3_shutdown_enter(flags, tcon->tid);
 187         if (flags > CIFS_GOING_FLAGS_NOLOGFLUSH) {
 188                 rc = -EINVAL;
 189                 goto shutdown_out_err;
 190         }
 191
 192         if (cifs_forced_shutdown(sbi))
 193                 goto shutdown_good;
 194
 195         cifs_dbg(VFS, "shut down requested (%d)", flags);
 196
 197         /*
 198          * see:
 199          *   https://man7.org/linux/man-pages/man2/ioctl_xfs_goingdown.2.html
 200          * for more information and description of original intent of the flags
 201          */
 202         switch (flags) {
 203         /*
 204          * We could add support later for default flag which requires:
 205          *     "Flush all dirty data and metadata to disk"
 206          * would need to call syncfs or equivalent to flush page cache for
 207          * the mount and then issue fsync to server (if nostrictsync not set)
 208          */
 209         case CIFS_GOING_FLAGS_DEFAULT:
 210                 cifs_dbg(FYI, "shutdown with default flag not supported\n");
 211                 rc = -EINVAL;
 212                 goto shutdown_out_err;
 213         /*
 214          * FLAGS_LOGFLUSH is easy since it asks to write out metadata (not
 215          * data) but metadata writes are not cached on the client, so can treat
 216          * it similarly to NOLOGFLUSH
 217          */
 218         case CIFS_GOING_FLAGS_LOGFLUSH:
 219         case CIFS_GOING_FLAGS_NOLOGFLUSH:
 220                 sbi->mnt_cifs_flags |= CIFS_MOUNT_SHUTDOWN;
 221                 goto shutdown_good;
 222         default:
 223                 rc = -EINVAL;
 224                 goto shutdown_out_err;
 225         }
 226
 227 shutdown_good:
 228         trace_smb3_shutdown_done(flags, tcon->tid);
 229         cifs_put_tlink(tlink);
 230         return 0;
 231 shutdown_out_err:
 232         trace_smb3_shutdown_err(rc, flags, tcon->tid);
 233         cifs_put_tlink(tlink);
 234         return rc;
 235 }
 236
 237 static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug_info __user *in)
 238 {
 239         struct smb3_full_key_debug_info out;
 240         struct cifs_ses *ses;
 241         int rc = 0;
 242         bool found = false;
 243         u8 __user *end;
 244
 245         if (!smb3_encryption_required(tcon)) {
 246                 rc = -EOPNOTSUPP;
 247                 goto out;
 248         }
 249
 250         /* copy user input into our output buffer */
 251         if (copy_from_user(&out, in, sizeof(out))) {
 252                 rc = -EINVAL;
 253                 goto out;
 254         }
 255
 256         if (!out.session_id) {
 257                 /* if ses id is 0, use current user session */
 258                 ses = tcon->ses;
 259         } else {
 260                 /* otherwise if a session id is given, look for it in all our sessions */
 261                 struct cifs_ses *ses_it = NULL;
 262                 struct TCP_Server_Info *server_it = NULL;
 263
 264                 spin_lock(&cifs_tcp_ses_lock);
 265                 list_for_each_entry(server_it, &cifs_tcp_ses_list, tcp_ses_list) {
 266                         list_for_each_entry(ses_it, &server_it->smb_ses_list, smb_ses_list) {
 267                                 spin_lock(&ses_it->ses_lock);
 268                                 if (ses_it->ses_status != SES_EXITING &&
 269                                     ses_it->Suid == out.session_id) {
 270                                         ses = ses_it;
 271                                         /*
 272                                          * since we are using the session outside the crit
 273                                          * section, we need to make sure it won't be released
 274                                          * so increment its refcount
 275                                          */
 276                                         cifs_smb_ses_inc_refcount(ses);
 277                                         spin_unlock(&ses_it->ses_lock);
 278                                         found = true;
 279                                         goto search_end;
 280                                 }
 281                                 spin_unlock(&ses_it->ses_lock);
 282                         }
 283                 }
 284 search_end:
 285                 spin_unlock(&cifs_tcp_ses_lock);
 286                 if (!found) {
 287                         rc = -ENOENT;
 288                         goto out;
 289                 }
 290         }
 291
 292         switch (ses->server->cipher_type) {
 293         case SMB2_ENCRYPTION_AES128_CCM:
 294         case SMB2_ENCRYPTION_AES128_GCM:
 295                 out.session_key_length = CIFS_SESS_KEY_SIZE;
 296                 out.server_in_key_length = out.server_out_key_length = SMB3_GCM128_CRYPTKEY_SIZE;
 297                 break;
 298         case SMB2_ENCRYPTION_AES256_CCM:
 299         case SMB2_ENCRYPTION_AES256_GCM:
 300                 out.session_key_length = CIFS_SESS_KEY_SIZE;
 301                 out.server_in_key_length = out.server_out_key_length = SMB3_GCM256_CRYPTKEY_SIZE;
 302                 break;
 303         default:
 304                 rc = -EOPNOTSUPP;
 305                 goto out;
 306         }
 307
 308         /* check if user buffer is big enough to store all the keys */
 309         if (out.in_size < sizeof(out) + out.session_key_length + out.server_in_key_length
 310             + out.server_out_key_length) {
 311                 rc = -ENOBUFS;
 312                 goto out;
 313         }
 314
 315         out.session_id = ses->Suid;
 316         out.cipher_type = le16_to_cpu(ses->server->cipher_type);
 317
 318         /* overwrite user input with our output */
 319         if (copy_to_user(in, &out, sizeof(out))) {
 320                 rc = -EINVAL;
 321                 goto out;
 322         }
 323
 324         /* append all the keys at the end of the user buffer */
 325         end = in->data;
 326         if (copy_to_user(end, ses->auth_key.response, out.session_key_length)) {
 327                 rc = -EINVAL;
 328                 goto out;
 329         }
 330         end += out.session_key_length;
 331
 332         if (copy_to_user(end, ses->smb3encryptionkey, out.server_in_key_length)) {
 333                 rc = -EINVAL;
 334                 goto out;
 335         }
 336         end += out.server_in_key_length;
 337
 338         if (copy_to_user(end, ses->smb3decryptionkey, out.server_out_key_length)) {
 339                 rc = -EINVAL;
 340                 goto out;
 341         }
 342
 343 out:
 344         if (found)
 345                 cifs_put_smb_ses(ses);
 346         return rc;
 347 }
 348
 349 long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 350 {
 351         struct inode *inode = file_inode(filep);
 352         struct smb3_key_debug_info pkey_inf;
 353         int rc = -ENOTTY; /* strange error - but the precedent */
 354         unsigned int xid;
 355         struct cifsFileInfo *pSMBFile = filep->private_data;
 356         struct cifs_tcon *tcon;
 357         struct tcon_link *tlink;
 358         struct cifs_sb_info *cifs_sb;
 359         __u64   ExtAttrBits = 0;
 360 #ifdef CONFIG_CIFS_POSIX
 361 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 362         __u64   caps;
 363 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 364 #endif /* CONFIG_CIFS_POSIX */
 365
 366         xid = get_xid();
 367
 368         cifs_dbg(FYI, "cifs ioctl 0x%x\n", command);
 369         if (pSMBFile == NULL)
 370                 trace_smb3_ioctl(xid, 0, command);
 371         else
 372                 trace_smb3_ioctl(xid, pSMBFile->fid.persistent_fid, command);
 373
 374         switch (command) {
 375                 case FS_IOC_GETFLAGS:
 376                         if (pSMBFile == NULL)
 377                                 break;
 378                         tcon = tlink_tcon(pSMBFile->tlink);
 379 #ifdef CONFIG_CIFS_POSIX
 380 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 381                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 382                         if (CIFS_UNIX_EXTATTR_CAP & caps) {
 383                                 __u64   ExtAttrMask = 0;
 384                                 rc = CIFSGetExtAttr(xid, tcon,
 385                                                     pSMBFile->fid.netfid,
 386                                                     &ExtAttrBits, &ExtAttrMask);
 387                                 if (rc == 0)
 388                                         rc = put_user(ExtAttrBits &
 389                                                 FS_FL_USER_VISIBLE,
 390                                                 (int __user *)arg);
 391                                 if (rc != -EOPNOTSUPP)
 392                                         break;
 393                         }
 394 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 395 #endif /* CONFIG_CIFS_POSIX */
 396                         rc = 0;
 397                         if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
 398                                 /* add in the compressed bit */
 399                                 ExtAttrBits = FS_COMPR_FL;
 400                                 rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
 401                                               (int __user *)arg);
 402                         }
 403                         break;
 404                 case FS_IOC_SETFLAGS:
 405                         if (pSMBFile == NULL)
 406                                 break;
 407                         tcon = tlink_tcon(pSMBFile->tlink);
 408                         /* caps = le64_to_cpu(tcon->fsUnixInfo.Capability); */
 409
 410                         if (get_user(ExtAttrBits, (int __user *)arg)) {
 411                                 rc = -EFAULT;
 412                                 break;
 413                         }
 414
 415                         /*
 416                          * if (CIFS_UNIX_EXTATTR_CAP & caps)
 417                          *      rc = CIFSSetExtAttr(xid, tcon,
 418                          *                     pSMBFile->fid.netfid,
 419                          *                     extAttrBits,
 420                          *                     &ExtAttrMask);
 421                          * if (rc != -EOPNOTSUPP)
 422                          *      break;
 423                          */
 424
 425                         /* Currently only flag we can set is compressed flag */
 426                         if ((ExtAttrBits & FS_COMPR_FL) == 0)
 427                                 break;
 428
 429                         /* Try to set compress flag */
 430                         if (tcon->ses->server->ops->set_compression) {
 431                                 rc = tcon->ses->server->ops->set_compression(
 432                                                         xid, tcon, pSMBFile);
 433                                 cifs_dbg(FYI, "set compress flag rc %d\n", rc);
 434                         }
 435                         break;
 436                 case CIFS_IOC_COPYCHUNK_FILE:
 437                         rc = cifs_ioctl_copychunk(xid, filep, arg);
 438                         break;
 439                 case CIFS_QUERY_INFO:
 440                         rc = cifs_ioctl_query_info(xid, filep, arg);
 441                         break;
 442                 case CIFS_IOC_SET_INTEGRITY:
 443                         if (pSMBFile == NULL)
 444                                 break;
 445                         tcon = tlink_tcon(pSMBFile->tlink);
 446                         if (tcon->ses->server->ops->set_integrity)
 447                                 rc = tcon->ses->server->ops->set_integrity(xid,
 448                                                 tcon, pSMBFile);
 449                         else
 450                                 rc = -EOPNOTSUPP;
 451                         break;
 452                 case CIFS_IOC_GET_MNT_INFO:
 453                         if (pSMBFile == NULL)
 454                                 break;
 455                         tcon = tlink_tcon(pSMBFile->tlink);
 456                         rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg);
 457                         break;
 458                 case CIFS_IOC_GET_TCON_INFO:
 459                         cifs_sb = CIFS_SB(inode->i_sb);
 460                         tlink = cifs_sb_tlink(cifs_sb);
 461                         if (IS_ERR(tlink)) {
 462                                 rc = PTR_ERR(tlink);
 463                                 break;
 464                         }
 465                         tcon = tlink_tcon(tlink);
 466                         rc = smb_mnt_get_tcon_info(tcon, (void __user *)arg);
 467                         cifs_put_tlink(tlink);
 468                         break;
 469                 case CIFS_ENUMERATE_SNAPSHOTS:
 470                         if (pSMBFile == NULL)
 471                                 break;
 472                         if (arg == 0) {
 473                                 rc = -EINVAL;
 474                                 goto cifs_ioc_exit;
 475                         }
 476                         tcon = tlink_tcon(pSMBFile->tlink);
 477                         if (tcon->ses->server->ops->enum_snapshots)
 478                                 rc = tcon->ses->server->ops->enum_snapshots(xid, tcon,
 479                                                 pSMBFile, (void __user *)arg);
 480                         else
 481                                 rc = -EOPNOTSUPP;
 482                         break;
 483                 case CIFS_DUMP_KEY:
 484                         /*
 485                          * Dump encryption keys. This is an old ioctl that only
 486                          * handles AES-128-{CCM,GCM}.
 487                          */
 488                         if (!capable(CAP_SYS_ADMIN)) {
 489                                 rc = -EACCES;
 490                                 break;
 491                         }
 492
 493                         cifs_sb = CIFS_SB(inode->i_sb);
 494                         tlink = cifs_sb_tlink(cifs_sb);
 495                         if (IS_ERR(tlink)) {
 496                                 rc = PTR_ERR(tlink);
 497                                 break;
 498                         }
 499                         tcon = tlink_tcon(tlink);
 500                         if (!smb3_encryption_required(tcon)) {
 501                                 rc = -EOPNOTSUPP;
 502                                 cifs_put_tlink(tlink);
 503                                 break;
 504                         }
 505                         pkey_inf.cipher_type =
 506                                 le16_to_cpu(tcon->ses->server->cipher_type);
 507                         pkey_inf.Suid = tcon->ses->Suid;
 508                         memcpy(pkey_inf.auth_key, tcon->ses->auth_key.response,
 509                                         16 /* SMB2_NTLMV2_SESSKEY_SIZE */);
 510                         memcpy(pkey_inf.smb3decryptionkey,
 511                               tcon->ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
 512                         memcpy(pkey_inf.smb3encryptionkey,
 513                               tcon->ses->smb3encryptionkey, SMB3_SIGN_KEY_SIZE);
 514                         if (copy_to_user((void __user *)arg, &pkey_inf,
 515                                         sizeof(struct smb3_key_debug_info)))
 516                                 rc = -EFAULT;
 517                         else
 518                                 rc = 0;
 519                         cifs_put_tlink(tlink);
 520                         break;
 521                 case CIFS_DUMP_FULL_KEY:
 522                         /*
 523                          * Dump encryption keys (handles any key sizes)
 524                          */
 525                         if (pSMBFile == NULL)
 526                                 break;
 527                         if (!capable(CAP_SYS_ADMIN)) {
 528                                 rc = -EACCES;
 529                                 break;
 530                         }
 531                         cifs_sb = CIFS_SB(inode->i_sb);
 532                         tlink = cifs_sb_tlink(cifs_sb);
 533                         if (IS_ERR(tlink)) {
 534                                 rc = PTR_ERR(tlink);
 535                                 break;
 536                         }
 537
 538                         tcon = tlink_tcon(tlink);
 539                         rc = cifs_dump_full_key(tcon, (void __user *)arg);
 540                         cifs_put_tlink(tlink);
 541                         break;
 542                 case CIFS_IOC_NOTIFY:
 543                         if (!S_ISDIR(inode->i_mode)) {
 544                                 /* Notify can only be done on directories */
 545                                 rc = -EOPNOTSUPP;
 546                                 break;
 547                         }
 548                         cifs_sb = CIFS_SB(inode->i_sb);
 549                         tlink = cifs_sb_tlink(cifs_sb);
 550                         if (IS_ERR(tlink)) {
 551                                 rc = PTR_ERR(tlink);
 552                                 break;
 553                         }
 554                         tcon = tlink_tcon(tlink);
 555                         if (tcon && tcon->ses->server->ops->notify) {
 556                                 rc = tcon->ses->server->ops->notify(xid,
 557                                                 filep, (void __user *)arg,
 558                                                 false /* no ret data */);
 559                                 cifs_dbg(FYI, "ioctl notify rc %d\n", rc);
 560                         } else
 561                                 rc = -EOPNOTSUPP;
 562                         cifs_put_tlink(tlink);
 563                         break;
 564                 case CIFS_IOC_NOTIFY_INFO:
 565                         if (!S_ISDIR(inode->i_mode)) {
 566                                 /* Notify can only be done on directories */
 567                                 rc = -EOPNOTSUPP;
 568                                 break;
 569                         }
 570                         cifs_sb = CIFS_SB(inode->i_sb);
 571                         tlink = cifs_sb_tlink(cifs_sb);
 572                         if (IS_ERR(tlink)) {
 573                                 rc = PTR_ERR(tlink);
 574                                 break;
 575                         }
 576                         tcon = tlink_tcon(tlink);
 577                         if (tcon && tcon->ses->server->ops->notify) {
 578                                 rc = tcon->ses->server->ops->notify(xid,
 579                                                 filep, (void __user *)arg,
 580                                                 true /* return details */);
 581                                 cifs_dbg(FYI, "ioctl notify info rc %d\n", rc);
 582                         } else
 583                                 rc = -EOPNOTSUPP;
 584                         cifs_put_tlink(tlink);
 585                         break;
 586                 case CIFS_IOC_SHUTDOWN:
 587                         rc = cifs_shutdown(inode->i_sb, arg);
 588                         break;
 589                 default:
 590                         cifs_dbg(FYI, "unsupported ioctl\n");
 591                         break;
 592         }
 593 cifs_ioc_exit:
 594         free_xid(xid);
 595         return rc;
 596 }