Pileus Git - ~andy/linux/blob - fs/cifs/smb2misc.c

   1 /*
   2  *   fs/cifs/smb2misc.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *                 Etersoft, 2012
   6  *   Author(s): Steve French (sfrench@us.ibm.com)
   7  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
   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 #include <linux/ctype.h>
  24 #include "smb2pdu.h"
  25 #include "cifsglob.h"
  26 #include "cifsproto.h"
  27 #include "smb2proto.h"
  28 #include "cifs_debug.h"
  29 #include "cifs_unicode.h"
  30 #include "smb2status.h"
  31
  32 static int
  33 check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
  34 {
  35         /*
  36          * Make sure that this really is an SMB, that it is a response,
  37          * and that the message ids match.
  38          */
  39         if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
  40             (mid == hdr->MessageId)) {
  41                 if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
  42                         return 0;
  43                 else {
  44                         /* only one valid case where server sends us request */
  45                         if (hdr->Command == SMB2_OPLOCK_BREAK)
  46                                 return 0;
  47                         else
  48                                 cERROR(1, "Received Request not response");
  49                 }
  50         } else { /* bad signature or mid */
  51                 if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
  52                         cERROR(1, "Bad protocol string signature header %x",
  53                                   *(unsigned int *) hdr->ProtocolId);
  54                 if (mid != hdr->MessageId)
  55                         cERROR(1, "Mids do not match: %llu and %llu", mid,
  56                                   hdr->MessageId);
  57         }
  58         cERROR(1, "Bad SMB detected. The Mid=%llu", hdr->MessageId);
  59         return 1;
  60 }
  61
  62 /*
  63  *  The following table defines the expected "StructureSize" of SMB2 responses
  64  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
  65  *
  66  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
  67  *  indexed by command in host byte order
  68  */
  69 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
  70         /* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
  71         /* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
  72         /* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
  73         /* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
  74         /* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
  75         /* SMB2_CREATE */ __constant_cpu_to_le16(89),
  76         /* SMB2_CLOSE */ __constant_cpu_to_le16(60),
  77         /* SMB2_FLUSH */ __constant_cpu_to_le16(4),
  78         /* SMB2_READ */ __constant_cpu_to_le16(17),
  79         /* SMB2_WRITE */ __constant_cpu_to_le16(17),
  80         /* SMB2_LOCK */ __constant_cpu_to_le16(4),
  81         /* SMB2_IOCTL */ __constant_cpu_to_le16(49),
  82         /* BB CHECK this ... not listed in documentation */
  83         /* SMB2_CANCEL */ __constant_cpu_to_le16(0),
  84         /* SMB2_ECHO */ __constant_cpu_to_le16(4),
  85         /* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
  86         /* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
  87         /* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
  88         /* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
  89         /* BB FIXME can also be 44 for lease break */
  90         /* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
  91 };
  92
  93 int
  94 smb2_check_message(char *buf, unsigned int length)
  95 {
  96         struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
  97         struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
  98         __u64 mid = hdr->MessageId;
  99         __u32 len = get_rfc1002_length(buf);
 100         __u32 clc_len;  /* calculated length */
 101         int command;
 102
 103         /* BB disable following printk later */
 104         cFYI(1, "%s length: 0x%x, smb_buf_length: 0x%x", __func__, length, len);
 105
 106         /*
 107          * Add function to do table lookup of StructureSize by command
 108          * ie Validate the wct via smb2_struct_sizes table above
 109          */
 110
 111         if (length < sizeof(struct smb2_pdu)) {
 112                 if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
 113                         pdu->StructureSize2 = 0;
 114                         /*
 115                          * As with SMB/CIFS, on some error cases servers may
 116                          * not return wct properly
 117                          */
 118                         return 0;
 119                 } else {
 120                         cERROR(1, "Length less than SMB header size");
 121                 }
 122                 return 1;
 123         }
 124         if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
 125                 cERROR(1, "SMB length greater than maximum, mid=%llu", mid);
 126                 return 1;
 127         }
 128
 129         if (check_smb2_hdr(hdr, mid))
 130                 return 1;
 131
 132         if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
 133                 cERROR(1, "Illegal structure size %u",
 134                           le16_to_cpu(hdr->StructureSize));
 135                 return 1;
 136         }
 137
 138         command = le16_to_cpu(hdr->Command);
 139         if (command >= NUMBER_OF_SMB2_COMMANDS) {
 140                 cERROR(1, "Illegal SMB2 command %d", command);
 141                 return 1;
 142         }
 143
 144         if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
 145                 if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
 146                     pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
 147                         /* error packets have 9 byte structure size */
 148                         cERROR(1, "Illegal response size %u for command %d",
 149                                    le16_to_cpu(pdu->StructureSize2), command);
 150                         return 1;
 151                 } else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
 152                            && (le16_to_cpu(pdu->StructureSize2) != 44)
 153                            && (le16_to_cpu(pdu->StructureSize2) != 36)) {
 154                         /* special case for SMB2.1 lease break message */
 155                         cERROR(1, "Illegal response size %d for oplock break",
 156                                    le16_to_cpu(pdu->StructureSize2));
 157                         return 1;
 158                 }
 159         }
 160
 161         if (4 + len != length) {
 162                 cERROR(1, "Total length %u RFC1002 length %u mismatch mid %llu",
 163                           length, 4 + len, mid);
 164                 return 1;
 165         }
 166
 167         clc_len = smb2_calc_size(hdr);
 168
 169         if (4 + len != clc_len) {
 170                 cFYI(1, "Calculated size %u length %u mismatch mid %llu",
 171                         clc_len, 4 + len, mid);
 172                 /* Windows 7 server returns 24 bytes more */
 173                 if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
 174                         return 0;
 175                 /* server can return one byte more */
 176                 if (clc_len == 4 + len + 1)
 177                         return 0;
 178                 return 1;
 179         }
 180         return 0;
 181 }
 182
 183 /*
 184  * The size of the variable area depends on the offset and length fields
 185  * located in different fields for various SMB2 responses. SMB2 responses
 186  * with no variable length info, show an offset of zero for the offset field.
 187  */
 188 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
 189         /* SMB2_NEGOTIATE */ true,
 190         /* SMB2_SESSION_SETUP */ true,
 191         /* SMB2_LOGOFF */ false,
 192         /* SMB2_TREE_CONNECT */ false,
 193         /* SMB2_TREE_DISCONNECT */ false,
 194         /* SMB2_CREATE */ true,
 195         /* SMB2_CLOSE */ false,
 196         /* SMB2_FLUSH */ false,
 197         /* SMB2_READ */ true,
 198         /* SMB2_WRITE */ false,
 199         /* SMB2_LOCK */ false,
 200         /* SMB2_IOCTL */ true,
 201         /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
 202         /* SMB2_ECHO */ false,
 203         /* SMB2_QUERY_DIRECTORY */ true,
 204         /* SMB2_CHANGE_NOTIFY */ true,
 205         /* SMB2_QUERY_INFO */ true,
 206         /* SMB2_SET_INFO */ false,
 207         /* SMB2_OPLOCK_BREAK */ false
 208 };
 209
 210 /*
 211  * Returns the pointer to the beginning of the data area. Length of the data
 212  * area and the offset to it (from the beginning of the smb are also returned.
 213  */
 214 char *
 215 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
 216 {
 217         *off = 0;
 218         *len = 0;
 219
 220         /* error responses do not have data area */
 221         if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
 222             (((struct smb2_err_rsp *)hdr)->StructureSize) ==
 223                                                 SMB2_ERROR_STRUCTURE_SIZE2)
 224                 return NULL;
 225
 226         /*
 227          * Following commands have data areas so we have to get the location
 228          * of the data buffer offset and data buffer length for the particular
 229          * command.
 230          */
 231         switch (hdr->Command) {
 232         case SMB2_NEGOTIATE:
 233                 *off = le16_to_cpu(
 234                     ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
 235                 *len = le16_to_cpu(
 236                     ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
 237                 break;
 238         case SMB2_SESSION_SETUP:
 239                 *off = le16_to_cpu(
 240                     ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
 241                 *len = le16_to_cpu(
 242                     ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
 243                 break;
 244         case SMB2_CREATE:
 245                 *off = le32_to_cpu(
 246                     ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
 247                 *len = le32_to_cpu(
 248                     ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
 249                 break;
 250         case SMB2_QUERY_INFO:
 251                 *off = le16_to_cpu(
 252                     ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
 253                 *len = le32_to_cpu(
 254                     ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
 255                 break;
 256         case SMB2_READ:
 257                 *off = ((struct smb2_read_rsp *)hdr)->DataOffset;
 258                 *len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
 259                 break;
 260         case SMB2_QUERY_DIRECTORY:
 261                 *off = le16_to_cpu(
 262                   ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
 263                 *len = le32_to_cpu(
 264                   ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
 265                 break;
 266         case SMB2_IOCTL:
 267         case SMB2_CHANGE_NOTIFY:
 268         default:
 269                 /* BB FIXME for unimplemented cases above */
 270                 cERROR(1, "no length check for command");
 271                 break;
 272         }
 273
 274         /*
 275          * Invalid length or offset probably means data area is invalid, but
 276          * we have little choice but to ignore the data area in this case.
 277          */
 278         if (*off > 4096) {
 279                 cERROR(1, "offset %d too large, data area ignored", *off);
 280                 *len = 0;
 281                 *off = 0;
 282         } else if (*off < 0) {
 283                 cERROR(1, "negative offset %d to data invalid ignore data area",
 284                           *off);
 285                 *off = 0;
 286                 *len = 0;
 287         } else if (*len < 0) {
 288                 cERROR(1, "negative data length %d invalid, data area ignored",
 289                           *len);
 290                 *len = 0;
 291         } else if (*len > 128 * 1024) {
 292                 cERROR(1, "data area larger than 128K: %d", *len);
 293                 *len = 0;
 294         }
 295
 296         /* return pointer to beginning of data area, ie offset from SMB start */
 297         if ((*off != 0) && (*len != 0))
 298                 return hdr->ProtocolId + *off;
 299         else
 300                 return NULL;
 301 }
 302
 303 /*
 304  * Calculate the size of the SMB message based on the fixed header
 305  * portion, the number of word parameters and the data portion of the message.
 306  */
 307 unsigned int
 308 smb2_calc_size(void *buf)
 309 {
 310         struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
 311         struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
 312         int offset; /* the offset from the beginning of SMB to data area */
 313         int data_length; /* the length of the variable length data area */
 314         /* Structure Size has already been checked to make sure it is 64 */
 315         int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
 316
 317         /*
 318          * StructureSize2, ie length of fixed parameter area has already
 319          * been checked to make sure it is the correct length.
 320          */
 321         len += le16_to_cpu(pdu->StructureSize2);
 322
 323         if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
 324                 goto calc_size_exit;
 325
 326         smb2_get_data_area_len(&offset, &data_length, hdr);
 327         cFYI(1, "SMB2 data length %d offset %d", data_length, offset);
 328
 329         if (data_length > 0) {
 330                 /*
 331                  * Check to make sure that data area begins after fixed area,
 332                  * Note that last byte of the fixed area is part of data area
 333                  * for some commands, typically those with odd StructureSize,
 334                  * so we must add one to the calculation (and 4 to account for
 335                  * the size of the RFC1001 hdr.
 336                  */
 337                 if (offset + 4 + 1 < len) {
 338                         cERROR(1, "data area offset %d overlaps SMB2 header %d",
 339                                   offset + 4 + 1, len);
 340                         data_length = 0;
 341                 } else {
 342                         len = 4 + offset + data_length;
 343                 }
 344         }
 345 calc_size_exit:
 346         cFYI(1, "SMB2 len %d", len);
 347         return len;
 348 }
 349
 350 /* Note: caller must free return buffer */
 351 __le16 *
 352 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
 353 {
 354         int len;
 355         const char *start_of_path;
 356         __le16 *to;
 357
 358         /* Windows doesn't allow paths beginning with \ */
 359         if (from[0] == '\\')
 360                 start_of_path = from + 1;
 361         else
 362                 start_of_path = from;
 363         to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
 364                                    cifs_sb->local_nls,
 365                                    cifs_sb->mnt_cifs_flags &
 366                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 367         return to;
 368 }
 369
 370 __le32
 371 smb2_get_lease_state(struct cifsInodeInfo *cinode)
 372 {
 373         if (cinode->clientCanCacheAll)
 374                 return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING;
 375         else if (cinode->clientCanCacheRead)
 376                 return SMB2_LEASE_READ_CACHING;
 377         return 0;
 378 }
 379
 380 __u8 smb2_map_lease_to_oplock(__le32 lease_state)
 381 {
 382         if (lease_state & SMB2_LEASE_WRITE_CACHING) {
 383                 if (lease_state & SMB2_LEASE_HANDLE_CACHING)
 384                         return SMB2_OPLOCK_LEVEL_BATCH;
 385                 else
 386                         return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
 387         } else if (lease_state & SMB2_LEASE_READ_CACHING)
 388                 return SMB2_OPLOCK_LEVEL_II;
 389         return 0;
 390 }
 391
 392 struct smb2_lease_break_work {
 393         struct work_struct lease_break;
 394         struct tcon_link *tlink;
 395         __u8 lease_key[16];
 396         __le32 lease_state;
 397 };
 398
 399 static void
 400 cifs_ses_oplock_break(struct work_struct *work)
 401 {
 402         struct smb2_lease_break_work *lw = container_of(work,
 403                                 struct smb2_lease_break_work, lease_break);
 404         int rc;
 405
 406         rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
 407                               lw->lease_state);
 408         cFYI(1, "Lease release rc %d", rc);
 409         cifs_put_tlink(lw->tlink);
 410         kfree(lw);
 411 }
 412
 413 static bool
 414 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
 415 {
 416         struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
 417         struct list_head *tmp, *tmp1, *tmp2;
 418         struct cifs_ses *ses;
 419         struct cifs_tcon *tcon;
 420         struct cifsInodeInfo *cinode;
 421         struct cifsFileInfo *cfile;
 422         struct cifs_pending_open *open;
 423         struct smb2_lease_break_work *lw;
 424         bool found;
 425         int ack_req = le32_to_cpu(rsp->Flags &
 426                                   SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
 427
 428         lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
 429         if (!lw) {
 430                 cERROR(1, "Memory allocation failed during lease break check");
 431                 return false;
 432         }
 433
 434         INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
 435         lw->lease_state = rsp->NewLeaseState;
 436
 437         cFYI(1, "Checking for lease break");
 438
 439         /* look up tcon based on tid & uid */
 440         spin_lock(&cifs_tcp_ses_lock);
 441         list_for_each(tmp, &server->smb_ses_list) {
 442                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 443
 444                 spin_lock(&cifs_file_list_lock);
 445                 list_for_each(tmp1, &ses->tcon_list) {
 446                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 447
 448                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
 449                         list_for_each(tmp2, &tcon->openFileList) {
 450                                 cfile = list_entry(tmp2, struct cifsFileInfo,
 451                                                    tlist);
 452                                 cinode = CIFS_I(cfile->dentry->d_inode);
 453
 454                                 if (memcmp(cinode->lease_key, rsp->LeaseKey,
 455                                            SMB2_LEASE_KEY_SIZE))
 456                                         continue;
 457
 458                                 cFYI(1, "found in the open list");
 459                                 cFYI(1, "lease key match, lease break 0x%d",
 460                                      le32_to_cpu(rsp->NewLeaseState));
 461
 462                                 smb2_set_oplock_level(cinode,
 463                                   smb2_map_lease_to_oplock(rsp->NewLeaseState));
 464
 465                                 if (ack_req)
 466                                         cfile->oplock_break_cancelled = false;
 467                                 else
 468                                         cfile->oplock_break_cancelled = true;
 469
 470                                 queue_work(cifsiod_wq, &cfile->oplock_break);
 471
 472                                 spin_unlock(&cifs_file_list_lock);
 473                                 spin_unlock(&cifs_tcp_ses_lock);
 474                                 return true;
 475                         }
 476
 477                         found = false;
 478                         list_for_each_entry(open, &tcon->pending_opens, olist) {
 479                                 if (memcmp(open->lease_key, rsp->LeaseKey,
 480                                            SMB2_LEASE_KEY_SIZE))
 481                                         continue;
 482
 483                                 if (!found && ack_req) {
 484                                         found = true;
 485                                         memcpy(lw->lease_key, open->lease_key,
 486                                                SMB2_LEASE_KEY_SIZE);
 487                                         lw->tlink = cifs_get_tlink(open->tlink);
 488                                         queue_work(cifsiod_wq,
 489                                                    &lw->lease_break);
 490                                 }
 491
 492                                 cFYI(1, "found in the pending open list");
 493                                 cFYI(1, "lease key match, lease break 0x%d",
 494                                      le32_to_cpu(rsp->NewLeaseState));
 495
 496                                 open->oplock =
 497                                   smb2_map_lease_to_oplock(rsp->NewLeaseState);
 498                         }
 499                         if (found) {
 500                                 spin_unlock(&cifs_file_list_lock);
 501                                 spin_unlock(&cifs_tcp_ses_lock);
 502                                 return true;
 503                         }
 504                 }
 505                 spin_unlock(&cifs_file_list_lock);
 506         }
 507         spin_unlock(&cifs_tcp_ses_lock);
 508         kfree(lw);
 509         cFYI(1, "Can not process lease break - no lease matched");
 510         return false;
 511 }
 512
 513 bool
 514 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 515 {
 516         struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
 517         struct list_head *tmp, *tmp1, *tmp2;
 518         struct cifs_ses *ses;
 519         struct cifs_tcon *tcon;
 520         struct cifsInodeInfo *cinode;
 521         struct cifsFileInfo *cfile;
 522
 523         cFYI(1, "Checking for oplock break");
 524
 525         if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
 526                 return false;
 527
 528         if (rsp->StructureSize !=
 529                                 smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 530                 if (le16_to_cpu(rsp->StructureSize) == 44)
 531                         return smb2_is_valid_lease_break(buffer, server);
 532                 else
 533                         return false;
 534         }
 535
 536         cFYI(1, "oplock level 0x%d", rsp->OplockLevel);
 537
 538         /* look up tcon based on tid & uid */
 539         spin_lock(&cifs_tcp_ses_lock);
 540         list_for_each(tmp, &server->smb_ses_list) {
 541                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 542                 list_for_each(tmp1, &ses->tcon_list) {
 543                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 544
 545                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
 546                         spin_lock(&cifs_file_list_lock);
 547                         list_for_each(tmp2, &tcon->openFileList) {
 548                                 cfile = list_entry(tmp2, struct cifsFileInfo,
 549                                                      tlist);
 550                                 if (rsp->PersistentFid !=
 551                                     cfile->fid.persistent_fid ||
 552                                     rsp->VolatileFid !=
 553                                     cfile->fid.volatile_fid)
 554                                         continue;
 555
 556                                 cFYI(1, "file id match, oplock break");
 557                                 cinode = CIFS_I(cfile->dentry->d_inode);
 558
 559                                 if (!cinode->clientCanCacheAll &&
 560                                     rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
 561                                         cfile->oplock_break_cancelled = true;
 562                                 else
 563                                         cfile->oplock_break_cancelled = false;
 564
 565                                 smb2_set_oplock_level(cinode,
 566                                   rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);
 567
 568                                 queue_work(cifsiod_wq, &cfile->oplock_break);
 569
 570                                 spin_unlock(&cifs_file_list_lock);
 571                                 spin_unlock(&cifs_tcp_ses_lock);
 572                                 return true;
 573                         }
 574                         spin_unlock(&cifs_file_list_lock);
 575                         spin_unlock(&cifs_tcp_ses_lock);
 576                         cFYI(1, "No matching file for oplock break");
 577                         return true;
 578                 }
 579         }
 580         spin_unlock(&cifs_tcp_ses_lock);
 581         cFYI(1, "Can not process oplock break for non-existent connection");
 582         return false;
 583 }