1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * 4 * Copyright (C) International Business Machines Corp., 2002,2008 5 * Author(s): Steve French (sfrench@us.ibm.com) 6 * 7 */ 8 9 #include <linux/slab.h> 10 #include <linux/ctype.h> 11 #include <linux/mempool.h> 12 #include <linux/vmalloc.h> 13 #include "cifspdu.h" 14 #include "cifsglob.h" 15 #include "cifsproto.h" 16 #include "cifs_debug.h" 17 #include "smberr.h" 18 #include "nterr.h" 19 #include "cifs_unicode.h" 20 #include "smb2pdu.h" 21 #include "cifsfs.h" 22 #ifdef CONFIG_CIFS_DFS_UPCALL 23 #include "dns_resolve.h" 24 #include "dfs_cache.h" 25 #include "dfs.h" 26 #endif 27 #include "fs_context.h" 28 #include "cached_dir.h" 29 30 /* The xid serves as a useful identifier for each incoming vfs request, 31 in a similar way to the mid which is useful to track each sent smb, 32 and CurrentXid can also provide a running counter (although it 33 will eventually wrap past zero) of the total vfs operations handled 34 since the cifs fs was mounted */ 35 36 unsigned int 37 _get_xid(void) 38 { 39 unsigned int xid; 40 41 spin_lock(&GlobalMid_Lock); 42 GlobalTotalActiveXid++; 43 44 /* keep high water mark for number of simultaneous ops in filesystem */ 45 if (GlobalTotalActiveXid > GlobalMaxActiveXid) 46 GlobalMaxActiveXid = GlobalTotalActiveXid; 47 if (GlobalTotalActiveXid > 65000) 48 cifs_dbg(FYI, "warning: more than 65000 requests active\n"); 49 xid = GlobalCurrentXid++; 50 spin_unlock(&GlobalMid_Lock); 51 return xid; 52 } 53 54 void 55 _free_xid(unsigned int xid) 56 { 57 spin_lock(&GlobalMid_Lock); 58 /* if (GlobalTotalActiveXid == 0) 59 BUG(); */ 60 GlobalTotalActiveXid--; 61 spin_unlock(&GlobalMid_Lock); 62 } 63 64 struct cifs_ses * 65 sesInfoAlloc(void) 66 { 67 struct cifs_ses *ret_buf; 68 69 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL); 70 if (ret_buf) { 71 atomic_inc(&sesInfoAllocCount); 72 spin_lock_init(&ret_buf->ses_lock); 73 ret_buf->ses_status = SES_NEW; 74 ++ret_buf->ses_count; 75 INIT_LIST_HEAD(&ret_buf->smb_ses_list); 76 INIT_LIST_HEAD(&ret_buf->tcon_list); 77 mutex_init(&ret_buf->session_mutex); 78 spin_lock_init(&ret_buf->iface_lock); 79 INIT_LIST_HEAD(&ret_buf->iface_list); 80 spin_lock_init(&ret_buf->chan_lock); 81 } 82 return ret_buf; 83 } 84 85 void 86 sesInfoFree(struct cifs_ses *buf_to_free) 87 { 88 struct cifs_server_iface *iface = NULL, *niface = NULL; 89 90 if (buf_to_free == NULL) { 91 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n"); 92 return; 93 } 94 95 unload_nls(buf_to_free->local_nls); 96 atomic_dec(&sesInfoAllocCount); 97 kfree(buf_to_free->serverOS); 98 kfree(buf_to_free->serverDomain); 99 kfree(buf_to_free->serverNOS); 100 kfree_sensitive(buf_to_free->password); 101 kfree(buf_to_free->user_name); 102 kfree(buf_to_free->domainName); 103 kfree_sensitive(buf_to_free->auth_key.response); 104 spin_lock(&buf_to_free->iface_lock); 105 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list, 106 iface_head) 107 kref_put(&iface->refcount, release_iface); 108 spin_unlock(&buf_to_free->iface_lock); 109 kfree_sensitive(buf_to_free); 110 } 111 112 struct cifs_tcon * 113 tcon_info_alloc(bool dir_leases_enabled) 114 { 115 struct cifs_tcon *ret_buf; 116 117 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); 118 if (!ret_buf) 119 return NULL; 120 121 if (dir_leases_enabled == true) { 122 ret_buf->cfids = init_cached_dirs(); 123 if (!ret_buf->cfids) { 124 kfree(ret_buf); 125 return NULL; 126 } 127 } 128 /* else ret_buf->cfids is already set to NULL above */ 129 130 atomic_inc(&tconInfoAllocCount); 131 ret_buf->status = TID_NEW; 132 ++ret_buf->tc_count; 133 spin_lock_init(&ret_buf->tc_lock); 134 INIT_LIST_HEAD(&ret_buf->openFileList); 135 INIT_LIST_HEAD(&ret_buf->tcon_list); 136 spin_lock_init(&ret_buf->open_file_lock); 137 spin_lock_init(&ret_buf->stat_lock); 138 atomic_set(&ret_buf->num_local_opens, 0); 139 atomic_set(&ret_buf->num_remote_opens, 0); 140 ret_buf->stats_from_time = ktime_get_real_seconds(); 141 142 return ret_buf; 143 } 144 145 void 146 tconInfoFree(struct cifs_tcon *tcon) 147 { 148 if (tcon == NULL) { 149 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); 150 return; 151 } 152 free_cached_dirs(tcon->cfids); 153 atomic_dec(&tconInfoAllocCount); 154 kfree(tcon->nativeFileSystem); 155 kfree_sensitive(tcon->password); 156 kfree(tcon->origin_fullpath); 157 kfree(tcon); 158 } 159 160 struct smb_hdr * 161 cifs_buf_get(void) 162 { 163 struct smb_hdr *ret_buf = NULL; 164 /* 165 * SMB2 header is bigger than CIFS one - no problems to clean some 166 * more bytes for CIFS. 167 */ 168 size_t buf_size = sizeof(struct smb2_hdr); 169 170 /* 171 * We could use negotiated size instead of max_msgsize - 172 * but it may be more efficient to always alloc same size 173 * albeit slightly larger than necessary and maxbuffersize 174 * defaults to this and can not be bigger. 175 */ 176 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); 177 178 /* clear the first few header bytes */ 179 /* for most paths, more is cleared in header_assemble */ 180 memset(ret_buf, 0, buf_size + 3); 181 atomic_inc(&buf_alloc_count); 182 #ifdef CONFIG_CIFS_STATS2 183 atomic_inc(&total_buf_alloc_count); 184 #endif /* CONFIG_CIFS_STATS2 */ 185 186 return ret_buf; 187 } 188 189 void 190 cifs_buf_release(void *buf_to_free) 191 { 192 if (buf_to_free == NULL) { 193 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ 194 return; 195 } 196 mempool_free(buf_to_free, cifs_req_poolp); 197 198 atomic_dec(&buf_alloc_count); 199 return; 200 } 201 202 struct smb_hdr * 203 cifs_small_buf_get(void) 204 { 205 struct smb_hdr *ret_buf = NULL; 206 207 /* We could use negotiated size instead of max_msgsize - 208 but it may be more efficient to always alloc same size 209 albeit slightly larger than necessary and maxbuffersize 210 defaults to this and can not be bigger */ 211 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); 212 /* No need to clear memory here, cleared in header assemble */ 213 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ 214 atomic_inc(&small_buf_alloc_count); 215 #ifdef CONFIG_CIFS_STATS2 216 atomic_inc(&total_small_buf_alloc_count); 217 #endif /* CONFIG_CIFS_STATS2 */ 218 219 return ret_buf; 220 } 221 222 void 223 cifs_small_buf_release(void *buf_to_free) 224 { 225 226 if (buf_to_free == NULL) { 227 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); 228 return; 229 } 230 mempool_free(buf_to_free, cifs_sm_req_poolp); 231 232 atomic_dec(&small_buf_alloc_count); 233 return; 234 } 235 236 void 237 free_rsp_buf(int resp_buftype, void *rsp) 238 { 239 if (resp_buftype == CIFS_SMALL_BUFFER) 240 cifs_small_buf_release(rsp); 241 else if (resp_buftype == CIFS_LARGE_BUFFER) 242 cifs_buf_release(rsp); 243 } 244 245 /* NB: MID can not be set if treeCon not passed in, in that 246 case it is responsbility of caller to set the mid */ 247 void 248 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , 249 const struct cifs_tcon *treeCon, int word_count 250 /* length of fixed section (word count) in two byte units */) 251 { 252 char *temp = (char *) buffer; 253 254 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ 255 256 buffer->smb_buf_length = cpu_to_be32( 257 (2 * word_count) + sizeof(struct smb_hdr) - 258 4 /* RFC 1001 length field does not count */ + 259 2 /* for bcc field itself */) ; 260 261 buffer->Protocol[0] = 0xFF; 262 buffer->Protocol[1] = 'S'; 263 buffer->Protocol[2] = 'M'; 264 buffer->Protocol[3] = 'B'; 265 buffer->Command = smb_command; 266 buffer->Flags = 0x00; /* case sensitive */ 267 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; 268 buffer->Pid = cpu_to_le16((__u16)current->tgid); 269 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); 270 if (treeCon) { 271 buffer->Tid = treeCon->tid; 272 if (treeCon->ses) { 273 if (treeCon->ses->capabilities & CAP_UNICODE) 274 buffer->Flags2 |= SMBFLG2_UNICODE; 275 if (treeCon->ses->capabilities & CAP_STATUS32) 276 buffer->Flags2 |= SMBFLG2_ERR_STATUS; 277 278 /* Uid is not converted */ 279 buffer->Uid = treeCon->ses->Suid; 280 if (treeCon->ses->server) 281 buffer->Mid = get_next_mid(treeCon->ses->server); 282 } 283 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) 284 buffer->Flags2 |= SMBFLG2_DFS; 285 if (treeCon->nocase) 286 buffer->Flags |= SMBFLG_CASELESS; 287 if ((treeCon->ses) && (treeCon->ses->server)) 288 if (treeCon->ses->server->sign) 289 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; 290 } 291 292 /* endian conversion of flags is now done just before sending */ 293 buffer->WordCount = (char) word_count; 294 return; 295 } 296 297 static int 298 check_smb_hdr(struct smb_hdr *smb) 299 { 300 /* does it have the right SMB "signature" ? */ 301 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) { 302 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", 303 *(unsigned int *)smb->Protocol); 304 return 1; 305 } 306 307 /* if it's a response then accept */ 308 if (smb->Flags & SMBFLG_RESPONSE) 309 return 0; 310 311 /* only one valid case where server sends us request */ 312 if (smb->Command == SMB_COM_LOCKING_ANDX) 313 return 0; 314 315 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", 316 get_mid(smb)); 317 return 1; 318 } 319 320 int 321 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server) 322 { 323 struct smb_hdr *smb = (struct smb_hdr *)buf; 324 __u32 rfclen = be32_to_cpu(smb->smb_buf_length); 325 __u32 clc_len; /* calculated length */ 326 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", 327 total_read, rfclen); 328 329 /* is this frame too small to even get to a BCC? */ 330 if (total_read < 2 + sizeof(struct smb_hdr)) { 331 if ((total_read >= sizeof(struct smb_hdr) - 1) 332 && (smb->Status.CifsError != 0)) { 333 /* it's an error return */ 334 smb->WordCount = 0; 335 /* some error cases do not return wct and bcc */ 336 return 0; 337 } else if ((total_read == sizeof(struct smb_hdr) + 1) && 338 (smb->WordCount == 0)) { 339 char *tmp = (char *)smb; 340 /* Need to work around a bug in two servers here */ 341 /* First, check if the part of bcc they sent was zero */ 342 if (tmp[sizeof(struct smb_hdr)] == 0) { 343 /* some servers return only half of bcc 344 * on simple responses (wct, bcc both zero) 345 * in particular have seen this on 346 * ulogoffX and FindClose. This leaves 347 * one byte of bcc potentially unitialized 348 */ 349 /* zero rest of bcc */ 350 tmp[sizeof(struct smb_hdr)+1] = 0; 351 return 0; 352 } 353 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); 354 } else { 355 cifs_dbg(VFS, "Length less than smb header size\n"); 356 } 357 return -EIO; 358 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) { 359 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n", 360 __func__, smb->WordCount); 361 return -EIO; 362 } 363 364 /* otherwise, there is enough to get to the BCC */ 365 if (check_smb_hdr(smb)) 366 return -EIO; 367 clc_len = smbCalcSize(smb); 368 369 if (4 + rfclen != total_read) { 370 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n", 371 rfclen); 372 return -EIO; 373 } 374 375 if (4 + rfclen != clc_len) { 376 __u16 mid = get_mid(smb); 377 /* check if bcc wrapped around for large read responses */ 378 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { 379 /* check if lengths match mod 64K */ 380 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) 381 return 0; /* bcc wrapped */ 382 } 383 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", 384 clc_len, 4 + rfclen, mid); 385 386 if (4 + rfclen < clc_len) { 387 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", 388 rfclen, mid); 389 return -EIO; 390 } else if (rfclen > clc_len + 512) { 391 /* 392 * Some servers (Windows XP in particular) send more 393 * data than the lengths in the SMB packet would 394 * indicate on certain calls (byte range locks and 395 * trans2 find first calls in particular). While the 396 * client can handle such a frame by ignoring the 397 * trailing data, we choose limit the amount of extra 398 * data to 512 bytes. 399 */ 400 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", 401 rfclen, mid); 402 return -EIO; 403 } 404 } 405 return 0; 406 } 407 408 bool 409 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) 410 { 411 struct smb_hdr *buf = (struct smb_hdr *)buffer; 412 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; 413 struct TCP_Server_Info *pserver; 414 struct cifs_ses *ses; 415 struct cifs_tcon *tcon; 416 struct cifsInodeInfo *pCifsInode; 417 struct cifsFileInfo *netfile; 418 419 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); 420 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && 421 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { 422 struct smb_com_transaction_change_notify_rsp *pSMBr = 423 (struct smb_com_transaction_change_notify_rsp *)buf; 424 struct file_notify_information *pnotify; 425 __u32 data_offset = 0; 426 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length); 427 428 if (get_bcc(buf) > sizeof(struct file_notify_information)) { 429 data_offset = le32_to_cpu(pSMBr->DataOffset); 430 431 if (data_offset > 432 len - sizeof(struct file_notify_information)) { 433 cifs_dbg(FYI, "Invalid data_offset %u\n", 434 data_offset); 435 return true; 436 } 437 pnotify = (struct file_notify_information *) 438 ((char *)&pSMBr->hdr.Protocol + data_offset); 439 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", 440 pnotify->FileName, pnotify->Action); 441 /* cifs_dump_mem("Rcvd notify Data: ",buf, 442 sizeof(struct smb_hdr)+60); */ 443 return true; 444 } 445 if (pSMBr->hdr.Status.CifsError) { 446 cifs_dbg(FYI, "notify err 0x%x\n", 447 pSMBr->hdr.Status.CifsError); 448 return true; 449 } 450 return false; 451 } 452 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) 453 return false; 454 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { 455 /* no sense logging error on invalid handle on oplock 456 break - harmless race between close request and oplock 457 break response is expected from time to time writing out 458 large dirty files cached on the client */ 459 if ((NT_STATUS_INVALID_HANDLE) == 460 le32_to_cpu(pSMB->hdr.Status.CifsError)) { 461 cifs_dbg(FYI, "Invalid handle on oplock break\n"); 462 return true; 463 } else if (ERRbadfid == 464 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { 465 return true; 466 } else { 467 return false; /* on valid oplock brk we get "request" */ 468 } 469 } 470 if (pSMB->hdr.WordCount != 8) 471 return false; 472 473 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", 474 pSMB->LockType, pSMB->OplockLevel); 475 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) 476 return false; 477 478 /* If server is a channel, select the primary channel */ 479 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv; 480 481 /* look up tcon based on tid & uid */ 482 spin_lock(&cifs_tcp_ses_lock); 483 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 484 if (cifs_ses_exiting(ses)) 485 continue; 486 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 487 if (tcon->tid != buf->Tid) 488 continue; 489 490 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); 491 spin_lock(&tcon->open_file_lock); 492 list_for_each_entry(netfile, &tcon->openFileList, tlist) { 493 if (pSMB->Fid != netfile->fid.netfid) 494 continue; 495 496 cifs_dbg(FYI, "file id match, oplock break\n"); 497 pCifsInode = CIFS_I(d_inode(netfile->dentry)); 498 499 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, 500 &pCifsInode->flags); 501 502 netfile->oplock_epoch = 0; 503 netfile->oplock_level = pSMB->OplockLevel; 504 netfile->oplock_break_cancelled = false; 505 cifs_queue_oplock_break(netfile); 506 507 spin_unlock(&tcon->open_file_lock); 508 spin_unlock(&cifs_tcp_ses_lock); 509 return true; 510 } 511 spin_unlock(&tcon->open_file_lock); 512 spin_unlock(&cifs_tcp_ses_lock); 513 cifs_dbg(FYI, "No matching file for oplock break\n"); 514 return true; 515 } 516 } 517 spin_unlock(&cifs_tcp_ses_lock); 518 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); 519 return true; 520 } 521 522 void 523 dump_smb(void *buf, int smb_buf_length) 524 { 525 if (traceSMB == 0) 526 return; 527 528 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, 529 smb_buf_length, true); 530 } 531 532 void 533 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) 534 { 535 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 536 struct cifs_tcon *tcon = NULL; 537 538 if (cifs_sb->master_tlink) 539 tcon = cifs_sb_master_tcon(cifs_sb); 540 541 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 542 cifs_sb->mnt_cifs_serverino_autodisabled = true; 543 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n", 544 tcon ? tcon->tree_name : "new server"); 545 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n"); 546 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n"); 547 548 } 549 } 550 551 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) 552 { 553 oplock &= 0xF; 554 555 if (oplock == OPLOCK_EXCLUSIVE) { 556 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; 557 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", 558 &cinode->netfs.inode); 559 } else if (oplock == OPLOCK_READ) { 560 cinode->oplock = CIFS_CACHE_READ_FLG; 561 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", 562 &cinode->netfs.inode); 563 } else 564 cinode->oplock = 0; 565 } 566 567 /* 568 * We wait for oplock breaks to be processed before we attempt to perform 569 * writes. 570 */ 571 int cifs_get_writer(struct cifsInodeInfo *cinode) 572 { 573 int rc; 574 575 start: 576 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, 577 TASK_KILLABLE); 578 if (rc) 579 return rc; 580 581 spin_lock(&cinode->writers_lock); 582 if (!cinode->writers) 583 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 584 cinode->writers++; 585 /* Check to see if we have started servicing an oplock break */ 586 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { 587 cinode->writers--; 588 if (cinode->writers == 0) { 589 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 590 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 591 } 592 spin_unlock(&cinode->writers_lock); 593 goto start; 594 } 595 spin_unlock(&cinode->writers_lock); 596 return 0; 597 } 598 599 void cifs_put_writer(struct cifsInodeInfo *cinode) 600 { 601 spin_lock(&cinode->writers_lock); 602 cinode->writers--; 603 if (cinode->writers == 0) { 604 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 605 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 606 } 607 spin_unlock(&cinode->writers_lock); 608 } 609 610 /** 611 * cifs_queue_oplock_break - queue the oplock break handler for cfile 612 * @cfile: The file to break the oplock on 613 * 614 * This function is called from the demultiplex thread when it 615 * receives an oplock break for @cfile. 616 * 617 * Assumes the tcon->open_file_lock is held. 618 * Assumes cfile->file_info_lock is NOT held. 619 */ 620 void cifs_queue_oplock_break(struct cifsFileInfo *cfile) 621 { 622 /* 623 * Bump the handle refcount now while we hold the 624 * open_file_lock to enforce the validity of it for the oplock 625 * break handler. The matching put is done at the end of the 626 * handler. 627 */ 628 cifsFileInfo_get(cfile); 629 630 queue_work(cifsoplockd_wq, &cfile->oplock_break); 631 } 632 633 void cifs_done_oplock_break(struct cifsInodeInfo *cinode) 634 { 635 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); 636 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); 637 } 638 639 bool 640 backup_cred(struct cifs_sb_info *cifs_sb) 641 { 642 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { 643 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid())) 644 return true; 645 } 646 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { 647 if (in_group_p(cifs_sb->ctx->backupgid)) 648 return true; 649 } 650 651 return false; 652 } 653 654 void 655 cifs_del_pending_open(struct cifs_pending_open *open) 656 { 657 spin_lock(&tlink_tcon(open->tlink)->open_file_lock); 658 list_del(&open->olist); 659 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 660 } 661 662 void 663 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, 664 struct cifs_pending_open *open) 665 { 666 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); 667 open->oplock = CIFS_OPLOCK_NO_CHANGE; 668 open->tlink = tlink; 669 fid->pending_open = open; 670 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); 671 } 672 673 void 674 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, 675 struct cifs_pending_open *open) 676 { 677 spin_lock(&tlink_tcon(tlink)->open_file_lock); 678 cifs_add_pending_open_locked(fid, tlink, open); 679 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 680 } 681 682 /* 683 * Critical section which runs after acquiring deferred_lock. 684 * As there is no reference count on cifs_deferred_close, pdclose 685 * should not be used outside deferred_lock. 686 */ 687 bool 688 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) 689 { 690 struct cifs_deferred_close *dclose; 691 692 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) { 693 if ((dclose->netfid == cfile->fid.netfid) && 694 (dclose->persistent_fid == cfile->fid.persistent_fid) && 695 (dclose->volatile_fid == cfile->fid.volatile_fid)) { 696 *pdclose = dclose; 697 return true; 698 } 699 } 700 return false; 701 } 702 703 /* 704 * Critical section which runs after acquiring deferred_lock. 705 */ 706 void 707 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) 708 { 709 bool is_deferred = false; 710 struct cifs_deferred_close *pdclose; 711 712 is_deferred = cifs_is_deferred_close(cfile, &pdclose); 713 if (is_deferred) { 714 kfree(dclose); 715 return; 716 } 717 718 dclose->tlink = cfile->tlink; 719 dclose->netfid = cfile->fid.netfid; 720 dclose->persistent_fid = cfile->fid.persistent_fid; 721 dclose->volatile_fid = cfile->fid.volatile_fid; 722 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); 723 } 724 725 /* 726 * Critical section which runs after acquiring deferred_lock. 727 */ 728 void 729 cifs_del_deferred_close(struct cifsFileInfo *cfile) 730 { 731 bool is_deferred = false; 732 struct cifs_deferred_close *dclose; 733 734 is_deferred = cifs_is_deferred_close(cfile, &dclose); 735 if (!is_deferred) 736 return; 737 list_del(&dclose->dlist); 738 kfree(dclose); 739 } 740 741 void 742 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) 743 { 744 struct cifsFileInfo *cfile = NULL; 745 struct file_list *tmp_list, *tmp_next_list; 746 struct list_head file_head; 747 748 if (cifs_inode == NULL) 749 return; 750 751 INIT_LIST_HEAD(&file_head); 752 spin_lock(&cifs_inode->open_file_lock); 753 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { 754 if (delayed_work_pending(&cfile->deferred)) { 755 if (cancel_delayed_work(&cfile->deferred)) { 756 spin_lock(&cifs_inode->deferred_lock); 757 cifs_del_deferred_close(cfile); 758 spin_unlock(&cifs_inode->deferred_lock); 759 760 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 761 if (tmp_list == NULL) 762 break; 763 tmp_list->cfile = cfile; 764 list_add_tail(&tmp_list->list, &file_head); 765 } 766 } 767 } 768 spin_unlock(&cifs_inode->open_file_lock); 769 770 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 771 _cifsFileInfo_put(tmp_list->cfile, false, false); 772 list_del(&tmp_list->list); 773 kfree(tmp_list); 774 } 775 } 776 777 void 778 cifs_close_all_deferred_files(struct cifs_tcon *tcon) 779 { 780 struct cifsFileInfo *cfile; 781 struct file_list *tmp_list, *tmp_next_list; 782 struct list_head file_head; 783 784 INIT_LIST_HEAD(&file_head); 785 spin_lock(&tcon->open_file_lock); 786 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 787 if (delayed_work_pending(&cfile->deferred)) { 788 if (cancel_delayed_work(&cfile->deferred)) { 789 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 790 cifs_del_deferred_close(cfile); 791 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 792 793 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 794 if (tmp_list == NULL) 795 break; 796 tmp_list->cfile = cfile; 797 list_add_tail(&tmp_list->list, &file_head); 798 } 799 } 800 } 801 spin_unlock(&tcon->open_file_lock); 802 803 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 804 _cifsFileInfo_put(tmp_list->cfile, true, false); 805 list_del(&tmp_list->list); 806 kfree(tmp_list); 807 } 808 } 809 void 810 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path) 811 { 812 struct cifsFileInfo *cfile; 813 struct file_list *tmp_list, *tmp_next_list; 814 struct list_head file_head; 815 void *page; 816 const char *full_path; 817 818 INIT_LIST_HEAD(&file_head); 819 page = alloc_dentry_path(); 820 spin_lock(&tcon->open_file_lock); 821 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 822 full_path = build_path_from_dentry(cfile->dentry, page); 823 if (strstr(full_path, path)) { 824 if (delayed_work_pending(&cfile->deferred)) { 825 if (cancel_delayed_work(&cfile->deferred)) { 826 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 827 cifs_del_deferred_close(cfile); 828 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 829 830 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 831 if (tmp_list == NULL) 832 break; 833 tmp_list->cfile = cfile; 834 list_add_tail(&tmp_list->list, &file_head); 835 } 836 } 837 } 838 } 839 spin_unlock(&tcon->open_file_lock); 840 841 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 842 _cifsFileInfo_put(tmp_list->cfile, true, false); 843 list_del(&tmp_list->list); 844 kfree(tmp_list); 845 } 846 free_dentry_path(page); 847 } 848 849 /* 850 * If a dentry has been deleted, all corresponding open handles should know that 851 * so that we do not defer close them. 852 */ 853 void cifs_mark_open_handles_for_deleted_file(struct inode *inode, 854 const char *path) 855 { 856 struct cifsFileInfo *cfile; 857 void *page; 858 const char *full_path; 859 struct cifsInodeInfo *cinode = CIFS_I(inode); 860 861 page = alloc_dentry_path(); 862 spin_lock(&cinode->open_file_lock); 863 864 /* 865 * note: we need to construct path from dentry and compare only if the 866 * inode has any hardlinks. When number of hardlinks is 1, we can just 867 * mark all open handles since they are going to be from the same file. 868 */ 869 if (inode->i_nlink > 1) { 870 list_for_each_entry(cfile, &cinode->openFileList, flist) { 871 full_path = build_path_from_dentry(cfile->dentry, page); 872 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0) 873 cfile->status_file_deleted = true; 874 } 875 } else { 876 list_for_each_entry(cfile, &cinode->openFileList, flist) 877 cfile->status_file_deleted = true; 878 } 879 spin_unlock(&cinode->open_file_lock); 880 free_dentry_path(page); 881 } 882 883 /* parses DFS referral V3 structure 884 * caller is responsible for freeing target_nodes 885 * returns: 886 * - on success - 0 887 * - on failure - errno 888 */ 889 int 890 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size, 891 unsigned int *num_of_nodes, 892 struct dfs_info3_param **target_nodes, 893 const struct nls_table *nls_codepage, int remap, 894 const char *searchName, bool is_unicode) 895 { 896 int i, rc = 0; 897 char *data_end; 898 struct dfs_referral_level_3 *ref; 899 900 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals); 901 902 if (*num_of_nodes < 1) { 903 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n", 904 *num_of_nodes); 905 rc = -EINVAL; 906 goto parse_DFS_referrals_exit; 907 } 908 909 ref = (struct dfs_referral_level_3 *) &(rsp->referrals); 910 if (ref->VersionNumber != cpu_to_le16(3)) { 911 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n", 912 le16_to_cpu(ref->VersionNumber)); 913 rc = -EINVAL; 914 goto parse_DFS_referrals_exit; 915 } 916 917 /* get the upper boundary of the resp buffer */ 918 data_end = (char *)rsp + rsp_size; 919 920 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n", 921 *num_of_nodes, le32_to_cpu(rsp->DFSFlags)); 922 923 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param), 924 GFP_KERNEL); 925 if (*target_nodes == NULL) { 926 rc = -ENOMEM; 927 goto parse_DFS_referrals_exit; 928 } 929 930 /* collect necessary data from referrals */ 931 for (i = 0; i < *num_of_nodes; i++) { 932 char *temp; 933 int max_len; 934 struct dfs_info3_param *node = (*target_nodes)+i; 935 936 node->flags = le32_to_cpu(rsp->DFSFlags); 937 if (is_unicode) { 938 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2, 939 GFP_KERNEL); 940 if (tmp == NULL) { 941 rc = -ENOMEM; 942 goto parse_DFS_referrals_exit; 943 } 944 cifsConvertToUTF16((__le16 *) tmp, searchName, 945 PATH_MAX, nls_codepage, remap); 946 node->path_consumed = cifs_utf16_bytes(tmp, 947 le16_to_cpu(rsp->PathConsumed), 948 nls_codepage); 949 kfree(tmp); 950 } else 951 node->path_consumed = le16_to_cpu(rsp->PathConsumed); 952 953 node->server_type = le16_to_cpu(ref->ServerType); 954 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); 955 956 /* copy DfsPath */ 957 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset); 958 max_len = data_end - temp; 959 node->path_name = cifs_strndup_from_utf16(temp, max_len, 960 is_unicode, nls_codepage); 961 if (!node->path_name) { 962 rc = -ENOMEM; 963 goto parse_DFS_referrals_exit; 964 } 965 966 /* copy link target UNC */ 967 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset); 968 max_len = data_end - temp; 969 node->node_name = cifs_strndup_from_utf16(temp, max_len, 970 is_unicode, nls_codepage); 971 if (!node->node_name) { 972 rc = -ENOMEM; 973 goto parse_DFS_referrals_exit; 974 } 975 976 node->ttl = le32_to_cpu(ref->TimeToLive); 977 978 ref++; 979 } 980 981 parse_DFS_referrals_exit: 982 if (rc) { 983 free_dfs_info_array(*target_nodes, *num_of_nodes); 984 *target_nodes = NULL; 985 *num_of_nodes = 0; 986 } 987 return rc; 988 } 989 990 struct cifs_aio_ctx * 991 cifs_aio_ctx_alloc(void) 992 { 993 struct cifs_aio_ctx *ctx; 994 995 /* 996 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io 997 * to false so that we know when we have to unreference pages within 998 * cifs_aio_ctx_release() 999 */ 1000 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL); 1001 if (!ctx) 1002 return NULL; 1003 1004 INIT_LIST_HEAD(&ctx->list); 1005 mutex_init(&ctx->aio_mutex); 1006 init_completion(&ctx->done); 1007 kref_init(&ctx->refcount); 1008 return ctx; 1009 } 1010 1011 void 1012 cifs_aio_ctx_release(struct kref *refcount) 1013 { 1014 struct cifs_aio_ctx *ctx = container_of(refcount, 1015 struct cifs_aio_ctx, refcount); 1016 1017 cifsFileInfo_put(ctx->cfile); 1018 1019 /* 1020 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly 1021 * which means that iov_iter_extract_pages() was a success and thus 1022 * that we may have references or pins on pages that we need to 1023 * release. 1024 */ 1025 if (ctx->bv) { 1026 if (ctx->should_dirty || ctx->bv_need_unpin) { 1027 unsigned int i; 1028 1029 for (i = 0; i < ctx->nr_pinned_pages; i++) { 1030 struct page *page = ctx->bv[i].bv_page; 1031 1032 if (ctx->should_dirty) 1033 set_page_dirty(page); 1034 if (ctx->bv_need_unpin) 1035 unpin_user_page(page); 1036 } 1037 } 1038 kvfree(ctx->bv); 1039 } 1040 1041 kfree(ctx); 1042 } 1043 1044 /** 1045 * cifs_alloc_hash - allocate hash and hash context together 1046 * @name: The name of the crypto hash algo 1047 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM 1048 * 1049 * The caller has to make sure @sdesc is initialized to either NULL or 1050 * a valid context. It can be freed via cifs_free_hash(). 1051 */ 1052 int 1053 cifs_alloc_hash(const char *name, struct shash_desc **sdesc) 1054 { 1055 int rc = 0; 1056 struct crypto_shash *alg = NULL; 1057 1058 if (*sdesc) 1059 return 0; 1060 1061 alg = crypto_alloc_shash(name, 0, 0); 1062 if (IS_ERR(alg)) { 1063 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name); 1064 rc = PTR_ERR(alg); 1065 *sdesc = NULL; 1066 return rc; 1067 } 1068 1069 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL); 1070 if (*sdesc == NULL) { 1071 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name); 1072 crypto_free_shash(alg); 1073 return -ENOMEM; 1074 } 1075 1076 (*sdesc)->tfm = alg; 1077 return 0; 1078 } 1079 1080 /** 1081 * cifs_free_hash - free hash and hash context together 1082 * @sdesc: Where to find the pointer to the hash TFM 1083 * 1084 * Freeing a NULL descriptor is safe. 1085 */ 1086 void 1087 cifs_free_hash(struct shash_desc **sdesc) 1088 { 1089 if (unlikely(!sdesc) || !*sdesc) 1090 return; 1091 1092 if ((*sdesc)->tfm) { 1093 crypto_free_shash((*sdesc)->tfm); 1094 (*sdesc)->tfm = NULL; 1095 } 1096 1097 kfree_sensitive(*sdesc); 1098 *sdesc = NULL; 1099 } 1100 1101 void extract_unc_hostname(const char *unc, const char **h, size_t *len) 1102 { 1103 const char *end; 1104 1105 /* skip initial slashes */ 1106 while (*unc && (*unc == '\\' || *unc == '/')) 1107 unc++; 1108 1109 end = unc; 1110 1111 while (*end && !(*end == '\\' || *end == '/')) 1112 end++; 1113 1114 *h = unc; 1115 *len = end - unc; 1116 } 1117 1118 /** 1119 * copy_path_name - copy src path to dst, possibly truncating 1120 * @dst: The destination buffer 1121 * @src: The source name 1122 * 1123 * returns number of bytes written (including trailing nul) 1124 */ 1125 int copy_path_name(char *dst, const char *src) 1126 { 1127 int name_len; 1128 1129 /* 1130 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it 1131 * will truncate and strlen(dst) will be PATH_MAX-1 1132 */ 1133 name_len = strscpy(dst, src, PATH_MAX); 1134 if (WARN_ON_ONCE(name_len < 0)) 1135 name_len = PATH_MAX-1; 1136 1137 /* we count the trailing nul */ 1138 name_len++; 1139 return name_len; 1140 } 1141 1142 struct super_cb_data { 1143 void *data; 1144 struct super_block *sb; 1145 }; 1146 1147 static void tcon_super_cb(struct super_block *sb, void *arg) 1148 { 1149 struct super_cb_data *sd = arg; 1150 struct cifs_sb_info *cifs_sb; 1151 struct cifs_tcon *t1 = sd->data, *t2; 1152 1153 if (sd->sb) 1154 return; 1155 1156 cifs_sb = CIFS_SB(sb); 1157 t2 = cifs_sb_master_tcon(cifs_sb); 1158 1159 spin_lock(&t2->tc_lock); 1160 if (t1->ses == t2->ses && 1161 t1->ses->server == t2->ses->server && 1162 t2->origin_fullpath && 1163 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) 1164 sd->sb = sb; 1165 spin_unlock(&t2->tc_lock); 1166 } 1167 1168 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), 1169 void *data) 1170 { 1171 struct super_cb_data sd = { 1172 .data = data, 1173 .sb = NULL, 1174 }; 1175 struct file_system_type **fs_type = (struct file_system_type *[]) { 1176 &cifs_fs_type, &smb3_fs_type, NULL, 1177 }; 1178 1179 for (; *fs_type; fs_type++) { 1180 iterate_supers_type(*fs_type, f, &sd); 1181 if (sd.sb) { 1182 /* 1183 * Grab an active reference in order to prevent automounts (DFS links) 1184 * of expiring and then freeing up our cifs superblock pointer while 1185 * we're doing failover. 1186 */ 1187 cifs_sb_active(sd.sb); 1188 return sd.sb; 1189 } 1190 } 1191 pr_warn_once("%s: could not find dfs superblock\n", __func__); 1192 return ERR_PTR(-EINVAL); 1193 } 1194 1195 static void __cifs_put_super(struct super_block *sb) 1196 { 1197 if (!IS_ERR_OR_NULL(sb)) 1198 cifs_sb_deactive(sb); 1199 } 1200 1201 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) 1202 { 1203 spin_lock(&tcon->tc_lock); 1204 if (!tcon->origin_fullpath) { 1205 spin_unlock(&tcon->tc_lock); 1206 return ERR_PTR(-ENOENT); 1207 } 1208 spin_unlock(&tcon->tc_lock); 1209 return __cifs_get_super(tcon_super_cb, tcon); 1210 } 1211 1212 void cifs_put_tcp_super(struct super_block *sb) 1213 { 1214 __cifs_put_super(sb); 1215 } 1216 1217 #ifdef CONFIG_CIFS_DFS_UPCALL 1218 int match_target_ip(struct TCP_Server_Info *server, 1219 const char *share, size_t share_len, 1220 bool *result) 1221 { 1222 int rc; 1223 char *target; 1224 struct sockaddr_storage ss; 1225 1226 *result = false; 1227 1228 target = kzalloc(share_len + 3, GFP_KERNEL); 1229 if (!target) 1230 return -ENOMEM; 1231 1232 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share); 1233 1234 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2); 1235 1236 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL); 1237 kfree(target); 1238 1239 if (rc < 0) 1240 return rc; 1241 1242 spin_lock(&server->srv_lock); 1243 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss); 1244 spin_unlock(&server->srv_lock); 1245 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result); 1246 return 0; 1247 } 1248 1249 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 1250 { 1251 int rc; 1252 1253 kfree(cifs_sb->prepath); 1254 cifs_sb->prepath = NULL; 1255 1256 if (prefix && *prefix) { 1257 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); 1258 if (IS_ERR(cifs_sb->prepath)) { 1259 rc = PTR_ERR(cifs_sb->prepath); 1260 cifs_sb->prepath = NULL; 1261 return rc; 1262 } 1263 if (cifs_sb->prepath) 1264 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); 1265 } 1266 1267 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; 1268 return 0; 1269 } 1270 1271 /* 1272 * Handle weird Windows SMB server behaviour. It responds with 1273 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for 1274 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains 1275 * non-ASCII unicode symbols. 1276 */ 1277 int cifs_inval_name_dfs_link_error(const unsigned int xid, 1278 struct cifs_tcon *tcon, 1279 struct cifs_sb_info *cifs_sb, 1280 const char *full_path, 1281 bool *islink) 1282 { 1283 struct cifs_ses *ses = tcon->ses; 1284 size_t len; 1285 char *path; 1286 char *ref_path; 1287 1288 *islink = false; 1289 1290 /* 1291 * Fast path - skip check when @full_path doesn't have a prefix path to 1292 * look up or tcon is not DFS. 1293 */ 1294 if (strlen(full_path) < 2 || !cifs_sb || 1295 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || 1296 !is_tcon_dfs(tcon)) 1297 return 0; 1298 1299 spin_lock(&tcon->tc_lock); 1300 if (!tcon->origin_fullpath) { 1301 spin_unlock(&tcon->tc_lock); 1302 return 0; 1303 } 1304 spin_unlock(&tcon->tc_lock); 1305 1306 /* 1307 * Slow path - tcon is DFS and @full_path has prefix path, so attempt 1308 * to get a referral to figure out whether it is an DFS link. 1309 */ 1310 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; 1311 path = kmalloc(len, GFP_KERNEL); 1312 if (!path) 1313 return -ENOMEM; 1314 1315 scnprintf(path, len, "%s%s", tcon->tree_name, full_path); 1316 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, 1317 cifs_remap(cifs_sb)); 1318 kfree(path); 1319 1320 if (IS_ERR(ref_path)) { 1321 if (PTR_ERR(ref_path) != -EINVAL) 1322 return PTR_ERR(ref_path); 1323 } else { 1324 struct dfs_info3_param *refs = NULL; 1325 int num_refs = 0; 1326 1327 /* 1328 * XXX: we are not using dfs_cache_find() here because we might 1329 * end up filling all the DFS cache and thus potentially 1330 * removing cached DFS targets that the client would eventually 1331 * need during failover. 1332 */ 1333 ses = CIFS_DFS_ROOT_SES(ses); 1334 if (ses->server->ops->get_dfs_refer && 1335 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, 1336 &num_refs, cifs_sb->local_nls, 1337 cifs_remap(cifs_sb))) 1338 *islink = refs[0].server_type == DFS_TYPE_LINK; 1339 free_dfs_info_array(refs, num_refs); 1340 kfree(ref_path); 1341 } 1342 return 0; 1343 } 1344 #endif 1345 1346 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) 1347 { 1348 int timeout = 10; 1349 int rc; 1350 1351 spin_lock(&server->srv_lock); 1352 if (server->tcpStatus != CifsNeedReconnect) { 1353 spin_unlock(&server->srv_lock); 1354 return 0; 1355 } 1356 timeout *= server->nr_targets; 1357 spin_unlock(&server->srv_lock); 1358 1359 /* 1360 * Give demultiplex thread up to 10 seconds to each target available for 1361 * reconnect -- should be greater than cifs socket timeout which is 7 1362 * seconds. 1363 * 1364 * On "soft" mounts we wait once. Hard mounts keep retrying until 1365 * process is killed or server comes back on-line. 1366 */ 1367 do { 1368 rc = wait_event_interruptible_timeout(server->response_q, 1369 (server->tcpStatus != CifsNeedReconnect), 1370 timeout * HZ); 1371 if (rc < 0) { 1372 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", 1373 __func__); 1374 return -ERESTARTSYS; 1375 } 1376 1377 /* are we still trying to reconnect? */ 1378 spin_lock(&server->srv_lock); 1379 if (server->tcpStatus != CifsNeedReconnect) { 1380 spin_unlock(&server->srv_lock); 1381 return 0; 1382 } 1383 spin_unlock(&server->srv_lock); 1384 } while (retry); 1385 1386 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); 1387 return -EHOSTDOWN; 1388 } 1389