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_sensitive(buf_to_free->password2); 102 kfree(buf_to_free->user_name); 103 kfree(buf_to_free->domainName); 104 kfree_sensitive(buf_to_free->auth_key.response); 105 spin_lock(&buf_to_free->iface_lock); 106 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list, 107 iface_head) 108 kref_put(&iface->refcount, release_iface); 109 spin_unlock(&buf_to_free->iface_lock); 110 kfree_sensitive(buf_to_free); 111 } 112 113 struct cifs_tcon * 114 tcon_info_alloc(bool dir_leases_enabled) 115 { 116 struct cifs_tcon *ret_buf; 117 118 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); 119 if (!ret_buf) 120 return NULL; 121 122 if (dir_leases_enabled == true) { 123 ret_buf->cfids = init_cached_dirs(); 124 if (!ret_buf->cfids) { 125 kfree(ret_buf); 126 return NULL; 127 } 128 } 129 /* else ret_buf->cfids is already set to NULL above */ 130 131 atomic_inc(&tconInfoAllocCount); 132 ret_buf->status = TID_NEW; 133 ++ret_buf->tc_count; 134 spin_lock_init(&ret_buf->tc_lock); 135 INIT_LIST_HEAD(&ret_buf->openFileList); 136 INIT_LIST_HEAD(&ret_buf->tcon_list); 137 spin_lock_init(&ret_buf->open_file_lock); 138 spin_lock_init(&ret_buf->stat_lock); 139 atomic_set(&ret_buf->num_local_opens, 0); 140 atomic_set(&ret_buf->num_remote_opens, 0); 141 ret_buf->stats_from_time = ktime_get_real_seconds(); 142 #ifdef CONFIG_CIFS_FSCACHE 143 mutex_init(&ret_buf->fscache_lock); 144 #endif 145 146 return ret_buf; 147 } 148 149 void 150 tconInfoFree(struct cifs_tcon *tcon) 151 { 152 if (tcon == NULL) { 153 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); 154 return; 155 } 156 free_cached_dirs(tcon->cfids); 157 atomic_dec(&tconInfoAllocCount); 158 kfree(tcon->nativeFileSystem); 159 kfree_sensitive(tcon->password); 160 kfree(tcon->origin_fullpath); 161 kfree(tcon); 162 } 163 164 struct smb_hdr * 165 cifs_buf_get(void) 166 { 167 struct smb_hdr *ret_buf = NULL; 168 /* 169 * SMB2 header is bigger than CIFS one - no problems to clean some 170 * more bytes for CIFS. 171 */ 172 size_t buf_size = sizeof(struct smb2_hdr); 173 174 /* 175 * We could use negotiated size instead of max_msgsize - 176 * but it may be more efficient to always alloc same size 177 * albeit slightly larger than necessary and maxbuffersize 178 * defaults to this and can not be bigger. 179 */ 180 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); 181 182 /* clear the first few header bytes */ 183 /* for most paths, more is cleared in header_assemble */ 184 memset(ret_buf, 0, buf_size + 3); 185 atomic_inc(&buf_alloc_count); 186 #ifdef CONFIG_CIFS_STATS2 187 atomic_inc(&total_buf_alloc_count); 188 #endif /* CONFIG_CIFS_STATS2 */ 189 190 return ret_buf; 191 } 192 193 void 194 cifs_buf_release(void *buf_to_free) 195 { 196 if (buf_to_free == NULL) { 197 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ 198 return; 199 } 200 mempool_free(buf_to_free, cifs_req_poolp); 201 202 atomic_dec(&buf_alloc_count); 203 return; 204 } 205 206 struct smb_hdr * 207 cifs_small_buf_get(void) 208 { 209 struct smb_hdr *ret_buf = NULL; 210 211 /* We could use negotiated size instead of max_msgsize - 212 but it may be more efficient to always alloc same size 213 albeit slightly larger than necessary and maxbuffersize 214 defaults to this and can not be bigger */ 215 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); 216 /* No need to clear memory here, cleared in header assemble */ 217 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ 218 atomic_inc(&small_buf_alloc_count); 219 #ifdef CONFIG_CIFS_STATS2 220 atomic_inc(&total_small_buf_alloc_count); 221 #endif /* CONFIG_CIFS_STATS2 */ 222 223 return ret_buf; 224 } 225 226 void 227 cifs_small_buf_release(void *buf_to_free) 228 { 229 230 if (buf_to_free == NULL) { 231 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); 232 return; 233 } 234 mempool_free(buf_to_free, cifs_sm_req_poolp); 235 236 atomic_dec(&small_buf_alloc_count); 237 return; 238 } 239 240 void 241 free_rsp_buf(int resp_buftype, void *rsp) 242 { 243 if (resp_buftype == CIFS_SMALL_BUFFER) 244 cifs_small_buf_release(rsp); 245 else if (resp_buftype == CIFS_LARGE_BUFFER) 246 cifs_buf_release(rsp); 247 } 248 249 /* NB: MID can not be set if treeCon not passed in, in that 250 case it is responsbility of caller to set the mid */ 251 void 252 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , 253 const struct cifs_tcon *treeCon, int word_count 254 /* length of fixed section (word count) in two byte units */) 255 { 256 char *temp = (char *) buffer; 257 258 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ 259 260 buffer->smb_buf_length = cpu_to_be32( 261 (2 * word_count) + sizeof(struct smb_hdr) - 262 4 /* RFC 1001 length field does not count */ + 263 2 /* for bcc field itself */) ; 264 265 buffer->Protocol[0] = 0xFF; 266 buffer->Protocol[1] = 'S'; 267 buffer->Protocol[2] = 'M'; 268 buffer->Protocol[3] = 'B'; 269 buffer->Command = smb_command; 270 buffer->Flags = 0x00; /* case sensitive */ 271 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; 272 buffer->Pid = cpu_to_le16((__u16)current->tgid); 273 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); 274 if (treeCon) { 275 buffer->Tid = treeCon->tid; 276 if (treeCon->ses) { 277 if (treeCon->ses->capabilities & CAP_UNICODE) 278 buffer->Flags2 |= SMBFLG2_UNICODE; 279 if (treeCon->ses->capabilities & CAP_STATUS32) 280 buffer->Flags2 |= SMBFLG2_ERR_STATUS; 281 282 /* Uid is not converted */ 283 buffer->Uid = treeCon->ses->Suid; 284 if (treeCon->ses->server) 285 buffer->Mid = get_next_mid(treeCon->ses->server); 286 } 287 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) 288 buffer->Flags2 |= SMBFLG2_DFS; 289 if (treeCon->nocase) 290 buffer->Flags |= SMBFLG_CASELESS; 291 if ((treeCon->ses) && (treeCon->ses->server)) 292 if (treeCon->ses->server->sign) 293 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; 294 } 295 296 /* endian conversion of flags is now done just before sending */ 297 buffer->WordCount = (char) word_count; 298 return; 299 } 300 301 static int 302 check_smb_hdr(struct smb_hdr *smb) 303 { 304 /* does it have the right SMB "signature" ? */ 305 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) { 306 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", 307 *(unsigned int *)smb->Protocol); 308 return 1; 309 } 310 311 /* if it's a response then accept */ 312 if (smb->Flags & SMBFLG_RESPONSE) 313 return 0; 314 315 /* only one valid case where server sends us request */ 316 if (smb->Command == SMB_COM_LOCKING_ANDX) 317 return 0; 318 319 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", 320 get_mid(smb)); 321 return 1; 322 } 323 324 int 325 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server) 326 { 327 struct smb_hdr *smb = (struct smb_hdr *)buf; 328 __u32 rfclen = be32_to_cpu(smb->smb_buf_length); 329 __u32 clc_len; /* calculated length */ 330 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", 331 total_read, rfclen); 332 333 /* is this frame too small to even get to a BCC? */ 334 if (total_read < 2 + sizeof(struct smb_hdr)) { 335 if ((total_read >= sizeof(struct smb_hdr) - 1) 336 && (smb->Status.CifsError != 0)) { 337 /* it's an error return */ 338 smb->WordCount = 0; 339 /* some error cases do not return wct and bcc */ 340 return 0; 341 } else if ((total_read == sizeof(struct smb_hdr) + 1) && 342 (smb->WordCount == 0)) { 343 char *tmp = (char *)smb; 344 /* Need to work around a bug in two servers here */ 345 /* First, check if the part of bcc they sent was zero */ 346 if (tmp[sizeof(struct smb_hdr)] == 0) { 347 /* some servers return only half of bcc 348 * on simple responses (wct, bcc both zero) 349 * in particular have seen this on 350 * ulogoffX and FindClose. This leaves 351 * one byte of bcc potentially unitialized 352 */ 353 /* zero rest of bcc */ 354 tmp[sizeof(struct smb_hdr)+1] = 0; 355 return 0; 356 } 357 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); 358 } else { 359 cifs_dbg(VFS, "Length less than smb header size\n"); 360 } 361 return -EIO; 362 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) { 363 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n", 364 __func__, smb->WordCount); 365 return -EIO; 366 } 367 368 /* otherwise, there is enough to get to the BCC */ 369 if (check_smb_hdr(smb)) 370 return -EIO; 371 clc_len = smbCalcSize(smb); 372 373 if (4 + rfclen != total_read) { 374 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n", 375 rfclen); 376 return -EIO; 377 } 378 379 if (4 + rfclen != clc_len) { 380 __u16 mid = get_mid(smb); 381 /* check if bcc wrapped around for large read responses */ 382 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { 383 /* check if lengths match mod 64K */ 384 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) 385 return 0; /* bcc wrapped */ 386 } 387 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", 388 clc_len, 4 + rfclen, mid); 389 390 if (4 + rfclen < clc_len) { 391 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", 392 rfclen, mid); 393 return -EIO; 394 } else if (rfclen > clc_len + 512) { 395 /* 396 * Some servers (Windows XP in particular) send more 397 * data than the lengths in the SMB packet would 398 * indicate on certain calls (byte range locks and 399 * trans2 find first calls in particular). While the 400 * client can handle such a frame by ignoring the 401 * trailing data, we choose limit the amount of extra 402 * data to 512 bytes. 403 */ 404 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", 405 rfclen, mid); 406 return -EIO; 407 } 408 } 409 return 0; 410 } 411 412 bool 413 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) 414 { 415 struct smb_hdr *buf = (struct smb_hdr *)buffer; 416 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; 417 struct TCP_Server_Info *pserver; 418 struct cifs_ses *ses; 419 struct cifs_tcon *tcon; 420 struct cifsInodeInfo *pCifsInode; 421 struct cifsFileInfo *netfile; 422 423 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); 424 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && 425 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { 426 struct smb_com_transaction_change_notify_rsp *pSMBr = 427 (struct smb_com_transaction_change_notify_rsp *)buf; 428 struct file_notify_information *pnotify; 429 __u32 data_offset = 0; 430 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length); 431 432 if (get_bcc(buf) > sizeof(struct file_notify_information)) { 433 data_offset = le32_to_cpu(pSMBr->DataOffset); 434 435 if (data_offset > 436 len - sizeof(struct file_notify_information)) { 437 cifs_dbg(FYI, "Invalid data_offset %u\n", 438 data_offset); 439 return true; 440 } 441 pnotify = (struct file_notify_information *) 442 ((char *)&pSMBr->hdr.Protocol + data_offset); 443 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", 444 pnotify->FileName, pnotify->Action); 445 /* cifs_dump_mem("Rcvd notify Data: ",buf, 446 sizeof(struct smb_hdr)+60); */ 447 return true; 448 } 449 if (pSMBr->hdr.Status.CifsError) { 450 cifs_dbg(FYI, "notify err 0x%x\n", 451 pSMBr->hdr.Status.CifsError); 452 return true; 453 } 454 return false; 455 } 456 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) 457 return false; 458 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { 459 /* no sense logging error on invalid handle on oplock 460 break - harmless race between close request and oplock 461 break response is expected from time to time writing out 462 large dirty files cached on the client */ 463 if ((NT_STATUS_INVALID_HANDLE) == 464 le32_to_cpu(pSMB->hdr.Status.CifsError)) { 465 cifs_dbg(FYI, "Invalid handle on oplock break\n"); 466 return true; 467 } else if (ERRbadfid == 468 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { 469 return true; 470 } else { 471 return false; /* on valid oplock brk we get "request" */ 472 } 473 } 474 if (pSMB->hdr.WordCount != 8) 475 return false; 476 477 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", 478 pSMB->LockType, pSMB->OplockLevel); 479 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) 480 return false; 481 482 /* If server is a channel, select the primary channel */ 483 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv; 484 485 /* look up tcon based on tid & uid */ 486 spin_lock(&cifs_tcp_ses_lock); 487 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 488 if (cifs_ses_exiting(ses)) 489 continue; 490 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 491 if (tcon->tid != buf->Tid) 492 continue; 493 494 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); 495 spin_lock(&tcon->open_file_lock); 496 list_for_each_entry(netfile, &tcon->openFileList, tlist) { 497 if (pSMB->Fid != netfile->fid.netfid) 498 continue; 499 500 cifs_dbg(FYI, "file id match, oplock break\n"); 501 pCifsInode = CIFS_I(d_inode(netfile->dentry)); 502 503 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, 504 &pCifsInode->flags); 505 506 netfile->oplock_epoch = 0; 507 netfile->oplock_level = pSMB->OplockLevel; 508 netfile->oplock_break_cancelled = false; 509 cifs_queue_oplock_break(netfile); 510 511 spin_unlock(&tcon->open_file_lock); 512 spin_unlock(&cifs_tcp_ses_lock); 513 return true; 514 } 515 spin_unlock(&tcon->open_file_lock); 516 spin_unlock(&cifs_tcp_ses_lock); 517 cifs_dbg(FYI, "No matching file for oplock break\n"); 518 return true; 519 } 520 } 521 spin_unlock(&cifs_tcp_ses_lock); 522 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); 523 return true; 524 } 525 526 void 527 dump_smb(void *buf, int smb_buf_length) 528 { 529 if (traceSMB == 0) 530 return; 531 532 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, 533 smb_buf_length, true); 534 } 535 536 void 537 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) 538 { 539 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 540 struct cifs_tcon *tcon = NULL; 541 542 if (cifs_sb->master_tlink) 543 tcon = cifs_sb_master_tcon(cifs_sb); 544 545 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 546 cifs_sb->mnt_cifs_serverino_autodisabled = true; 547 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n", 548 tcon ? tcon->tree_name : "new server"); 549 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n"); 550 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n"); 551 552 } 553 } 554 555 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) 556 { 557 oplock &= 0xF; 558 559 if (oplock == OPLOCK_EXCLUSIVE) { 560 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; 561 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", 562 &cinode->netfs.inode); 563 } else if (oplock == OPLOCK_READ) { 564 cinode->oplock = CIFS_CACHE_READ_FLG; 565 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", 566 &cinode->netfs.inode); 567 } else 568 cinode->oplock = 0; 569 } 570 571 /* 572 * We wait for oplock breaks to be processed before we attempt to perform 573 * writes. 574 */ 575 int cifs_get_writer(struct cifsInodeInfo *cinode) 576 { 577 int rc; 578 579 start: 580 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, 581 TASK_KILLABLE); 582 if (rc) 583 return rc; 584 585 spin_lock(&cinode->writers_lock); 586 if (!cinode->writers) 587 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 588 cinode->writers++; 589 /* Check to see if we have started servicing an oplock break */ 590 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { 591 cinode->writers--; 592 if (cinode->writers == 0) { 593 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 594 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 595 } 596 spin_unlock(&cinode->writers_lock); 597 goto start; 598 } 599 spin_unlock(&cinode->writers_lock); 600 return 0; 601 } 602 603 void cifs_put_writer(struct cifsInodeInfo *cinode) 604 { 605 spin_lock(&cinode->writers_lock); 606 cinode->writers--; 607 if (cinode->writers == 0) { 608 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 609 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 610 } 611 spin_unlock(&cinode->writers_lock); 612 } 613 614 /** 615 * cifs_queue_oplock_break - queue the oplock break handler for cfile 616 * @cfile: The file to break the oplock on 617 * 618 * This function is called from the demultiplex thread when it 619 * receives an oplock break for @cfile. 620 * 621 * Assumes the tcon->open_file_lock is held. 622 * Assumes cfile->file_info_lock is NOT held. 623 */ 624 void cifs_queue_oplock_break(struct cifsFileInfo *cfile) 625 { 626 /* 627 * Bump the handle refcount now while we hold the 628 * open_file_lock to enforce the validity of it for the oplock 629 * break handler. The matching put is done at the end of the 630 * handler. 631 */ 632 cifsFileInfo_get(cfile); 633 634 queue_work(cifsoplockd_wq, &cfile->oplock_break); 635 } 636 637 void cifs_done_oplock_break(struct cifsInodeInfo *cinode) 638 { 639 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); 640 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); 641 } 642 643 bool 644 backup_cred(struct cifs_sb_info *cifs_sb) 645 { 646 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { 647 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid())) 648 return true; 649 } 650 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { 651 if (in_group_p(cifs_sb->ctx->backupgid)) 652 return true; 653 } 654 655 return false; 656 } 657 658 void 659 cifs_del_pending_open(struct cifs_pending_open *open) 660 { 661 spin_lock(&tlink_tcon(open->tlink)->open_file_lock); 662 list_del(&open->olist); 663 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 664 } 665 666 void 667 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, 668 struct cifs_pending_open *open) 669 { 670 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); 671 open->oplock = CIFS_OPLOCK_NO_CHANGE; 672 open->tlink = tlink; 673 fid->pending_open = open; 674 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); 675 } 676 677 void 678 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, 679 struct cifs_pending_open *open) 680 { 681 spin_lock(&tlink_tcon(tlink)->open_file_lock); 682 cifs_add_pending_open_locked(fid, tlink, open); 683 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 684 } 685 686 /* 687 * Critical section which runs after acquiring deferred_lock. 688 * As there is no reference count on cifs_deferred_close, pdclose 689 * should not be used outside deferred_lock. 690 */ 691 bool 692 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) 693 { 694 struct cifs_deferred_close *dclose; 695 696 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) { 697 if ((dclose->netfid == cfile->fid.netfid) && 698 (dclose->persistent_fid == cfile->fid.persistent_fid) && 699 (dclose->volatile_fid == cfile->fid.volatile_fid)) { 700 *pdclose = dclose; 701 return true; 702 } 703 } 704 return false; 705 } 706 707 /* 708 * Critical section which runs after acquiring deferred_lock. 709 */ 710 void 711 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) 712 { 713 bool is_deferred = false; 714 struct cifs_deferred_close *pdclose; 715 716 is_deferred = cifs_is_deferred_close(cfile, &pdclose); 717 if (is_deferred) { 718 kfree(dclose); 719 return; 720 } 721 722 dclose->tlink = cfile->tlink; 723 dclose->netfid = cfile->fid.netfid; 724 dclose->persistent_fid = cfile->fid.persistent_fid; 725 dclose->volatile_fid = cfile->fid.volatile_fid; 726 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); 727 } 728 729 /* 730 * Critical section which runs after acquiring deferred_lock. 731 */ 732 void 733 cifs_del_deferred_close(struct cifsFileInfo *cfile) 734 { 735 bool is_deferred = false; 736 struct cifs_deferred_close *dclose; 737 738 is_deferred = cifs_is_deferred_close(cfile, &dclose); 739 if (!is_deferred) 740 return; 741 list_del(&dclose->dlist); 742 kfree(dclose); 743 } 744 745 void 746 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) 747 { 748 struct cifsFileInfo *cfile = NULL; 749 struct file_list *tmp_list, *tmp_next_list; 750 struct list_head file_head; 751 752 if (cifs_inode == NULL) 753 return; 754 755 INIT_LIST_HEAD(&file_head); 756 spin_lock(&cifs_inode->open_file_lock); 757 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { 758 if (delayed_work_pending(&cfile->deferred)) { 759 if (cancel_delayed_work(&cfile->deferred)) { 760 spin_lock(&cifs_inode->deferred_lock); 761 cifs_del_deferred_close(cfile); 762 spin_unlock(&cifs_inode->deferred_lock); 763 764 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 765 if (tmp_list == NULL) 766 break; 767 tmp_list->cfile = cfile; 768 list_add_tail(&tmp_list->list, &file_head); 769 } 770 } 771 } 772 spin_unlock(&cifs_inode->open_file_lock); 773 774 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 775 _cifsFileInfo_put(tmp_list->cfile, false, false); 776 list_del(&tmp_list->list); 777 kfree(tmp_list); 778 } 779 } 780 781 void 782 cifs_close_all_deferred_files(struct cifs_tcon *tcon) 783 { 784 struct cifsFileInfo *cfile; 785 struct file_list *tmp_list, *tmp_next_list; 786 struct list_head file_head; 787 788 INIT_LIST_HEAD(&file_head); 789 spin_lock(&tcon->open_file_lock); 790 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 791 if (delayed_work_pending(&cfile->deferred)) { 792 if (cancel_delayed_work(&cfile->deferred)) { 793 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 794 cifs_del_deferred_close(cfile); 795 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 796 797 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 798 if (tmp_list == NULL) 799 break; 800 tmp_list->cfile = cfile; 801 list_add_tail(&tmp_list->list, &file_head); 802 } 803 } 804 } 805 spin_unlock(&tcon->open_file_lock); 806 807 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 808 _cifsFileInfo_put(tmp_list->cfile, true, false); 809 list_del(&tmp_list->list); 810 kfree(tmp_list); 811 } 812 } 813 void 814 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path) 815 { 816 struct cifsFileInfo *cfile; 817 struct file_list *tmp_list, *tmp_next_list; 818 struct list_head file_head; 819 void *page; 820 const char *full_path; 821 822 INIT_LIST_HEAD(&file_head); 823 page = alloc_dentry_path(); 824 spin_lock(&tcon->open_file_lock); 825 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 826 full_path = build_path_from_dentry(cfile->dentry, page); 827 if (strstr(full_path, path)) { 828 if (delayed_work_pending(&cfile->deferred)) { 829 if (cancel_delayed_work(&cfile->deferred)) { 830 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 831 cifs_del_deferred_close(cfile); 832 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 833 834 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 835 if (tmp_list == NULL) 836 break; 837 tmp_list->cfile = cfile; 838 list_add_tail(&tmp_list->list, &file_head); 839 } 840 } 841 } 842 } 843 spin_unlock(&tcon->open_file_lock); 844 845 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 846 _cifsFileInfo_put(tmp_list->cfile, true, false); 847 list_del(&tmp_list->list); 848 kfree(tmp_list); 849 } 850 free_dentry_path(page); 851 } 852 853 /* 854 * If a dentry has been deleted, all corresponding open handles should know that 855 * so that we do not defer close them. 856 */ 857 void cifs_mark_open_handles_for_deleted_file(struct inode *inode, 858 const char *path) 859 { 860 struct cifsFileInfo *cfile; 861 void *page; 862 const char *full_path; 863 struct cifsInodeInfo *cinode = CIFS_I(inode); 864 865 page = alloc_dentry_path(); 866 spin_lock(&cinode->open_file_lock); 867 868 /* 869 * note: we need to construct path from dentry and compare only if the 870 * inode has any hardlinks. When number of hardlinks is 1, we can just 871 * mark all open handles since they are going to be from the same file. 872 */ 873 if (inode->i_nlink > 1) { 874 list_for_each_entry(cfile, &cinode->openFileList, flist) { 875 full_path = build_path_from_dentry(cfile->dentry, page); 876 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0) 877 cfile->status_file_deleted = true; 878 } 879 } else { 880 list_for_each_entry(cfile, &cinode->openFileList, flist) 881 cfile->status_file_deleted = true; 882 } 883 spin_unlock(&cinode->open_file_lock); 884 free_dentry_path(page); 885 } 886 887 /* parses DFS referral V3 structure 888 * caller is responsible for freeing target_nodes 889 * returns: 890 * - on success - 0 891 * - on failure - errno 892 */ 893 int 894 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size, 895 unsigned int *num_of_nodes, 896 struct dfs_info3_param **target_nodes, 897 const struct nls_table *nls_codepage, int remap, 898 const char *searchName, bool is_unicode) 899 { 900 int i, rc = 0; 901 char *data_end; 902 struct dfs_referral_level_3 *ref; 903 904 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals); 905 906 if (*num_of_nodes < 1) { 907 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n", 908 *num_of_nodes); 909 rc = -EINVAL; 910 goto parse_DFS_referrals_exit; 911 } 912 913 ref = (struct dfs_referral_level_3 *) &(rsp->referrals); 914 if (ref->VersionNumber != cpu_to_le16(3)) { 915 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n", 916 le16_to_cpu(ref->VersionNumber)); 917 rc = -EINVAL; 918 goto parse_DFS_referrals_exit; 919 } 920 921 /* get the upper boundary of the resp buffer */ 922 data_end = (char *)rsp + rsp_size; 923 924 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n", 925 *num_of_nodes, le32_to_cpu(rsp->DFSFlags)); 926 927 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param), 928 GFP_KERNEL); 929 if (*target_nodes == NULL) { 930 rc = -ENOMEM; 931 goto parse_DFS_referrals_exit; 932 } 933 934 /* collect necessary data from referrals */ 935 for (i = 0; i < *num_of_nodes; i++) { 936 char *temp; 937 int max_len; 938 struct dfs_info3_param *node = (*target_nodes)+i; 939 940 node->flags = le32_to_cpu(rsp->DFSFlags); 941 if (is_unicode) { 942 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2, 943 GFP_KERNEL); 944 if (tmp == NULL) { 945 rc = -ENOMEM; 946 goto parse_DFS_referrals_exit; 947 } 948 cifsConvertToUTF16((__le16 *) tmp, searchName, 949 PATH_MAX, nls_codepage, remap); 950 node->path_consumed = cifs_utf16_bytes(tmp, 951 le16_to_cpu(rsp->PathConsumed), 952 nls_codepage); 953 kfree(tmp); 954 } else 955 node->path_consumed = le16_to_cpu(rsp->PathConsumed); 956 957 node->server_type = le16_to_cpu(ref->ServerType); 958 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); 959 960 /* copy DfsPath */ 961 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset); 962 max_len = data_end - temp; 963 node->path_name = cifs_strndup_from_utf16(temp, max_len, 964 is_unicode, nls_codepage); 965 if (!node->path_name) { 966 rc = -ENOMEM; 967 goto parse_DFS_referrals_exit; 968 } 969 970 /* copy link target UNC */ 971 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset); 972 max_len = data_end - temp; 973 node->node_name = cifs_strndup_from_utf16(temp, max_len, 974 is_unicode, nls_codepage); 975 if (!node->node_name) { 976 rc = -ENOMEM; 977 goto parse_DFS_referrals_exit; 978 } 979 980 node->ttl = le32_to_cpu(ref->TimeToLive); 981 982 ref++; 983 } 984 985 parse_DFS_referrals_exit: 986 if (rc) { 987 free_dfs_info_array(*target_nodes, *num_of_nodes); 988 *target_nodes = NULL; 989 *num_of_nodes = 0; 990 } 991 return rc; 992 } 993 994 struct cifs_aio_ctx * 995 cifs_aio_ctx_alloc(void) 996 { 997 struct cifs_aio_ctx *ctx; 998 999 /* 1000 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io 1001 * to false so that we know when we have to unreference pages within 1002 * cifs_aio_ctx_release() 1003 */ 1004 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL); 1005 if (!ctx) 1006 return NULL; 1007 1008 INIT_LIST_HEAD(&ctx->list); 1009 mutex_init(&ctx->aio_mutex); 1010 init_completion(&ctx->done); 1011 kref_init(&ctx->refcount); 1012 return ctx; 1013 } 1014 1015 void 1016 cifs_aio_ctx_release(struct kref *refcount) 1017 { 1018 struct cifs_aio_ctx *ctx = container_of(refcount, 1019 struct cifs_aio_ctx, refcount); 1020 1021 cifsFileInfo_put(ctx->cfile); 1022 1023 /* 1024 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly 1025 * which means that iov_iter_extract_pages() was a success and thus 1026 * that we may have references or pins on pages that we need to 1027 * release. 1028 */ 1029 if (ctx->bv) { 1030 if (ctx->should_dirty || ctx->bv_need_unpin) { 1031 unsigned int i; 1032 1033 for (i = 0; i < ctx->nr_pinned_pages; i++) { 1034 struct page *page = ctx->bv[i].bv_page; 1035 1036 if (ctx->should_dirty) 1037 set_page_dirty(page); 1038 if (ctx->bv_need_unpin) 1039 unpin_user_page(page); 1040 } 1041 } 1042 kvfree(ctx->bv); 1043 } 1044 1045 kfree(ctx); 1046 } 1047 1048 /** 1049 * cifs_alloc_hash - allocate hash and hash context together 1050 * @name: The name of the crypto hash algo 1051 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM 1052 * 1053 * The caller has to make sure @sdesc is initialized to either NULL or 1054 * a valid context. It can be freed via cifs_free_hash(). 1055 */ 1056 int 1057 cifs_alloc_hash(const char *name, struct shash_desc **sdesc) 1058 { 1059 int rc = 0; 1060 struct crypto_shash *alg = NULL; 1061 1062 if (*sdesc) 1063 return 0; 1064 1065 alg = crypto_alloc_shash(name, 0, 0); 1066 if (IS_ERR(alg)) { 1067 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name); 1068 rc = PTR_ERR(alg); 1069 *sdesc = NULL; 1070 return rc; 1071 } 1072 1073 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL); 1074 if (*sdesc == NULL) { 1075 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name); 1076 crypto_free_shash(alg); 1077 return -ENOMEM; 1078 } 1079 1080 (*sdesc)->tfm = alg; 1081 return 0; 1082 } 1083 1084 /** 1085 * cifs_free_hash - free hash and hash context together 1086 * @sdesc: Where to find the pointer to the hash TFM 1087 * 1088 * Freeing a NULL descriptor is safe. 1089 */ 1090 void 1091 cifs_free_hash(struct shash_desc **sdesc) 1092 { 1093 if (unlikely(!sdesc) || !*sdesc) 1094 return; 1095 1096 if ((*sdesc)->tfm) { 1097 crypto_free_shash((*sdesc)->tfm); 1098 (*sdesc)->tfm = NULL; 1099 } 1100 1101 kfree_sensitive(*sdesc); 1102 *sdesc = NULL; 1103 } 1104 1105 void extract_unc_hostname(const char *unc, const char **h, size_t *len) 1106 { 1107 const char *end; 1108 1109 /* skip initial slashes */ 1110 while (*unc && (*unc == '\\' || *unc == '/')) 1111 unc++; 1112 1113 end = unc; 1114 1115 while (*end && !(*end == '\\' || *end == '/')) 1116 end++; 1117 1118 *h = unc; 1119 *len = end - unc; 1120 } 1121 1122 /** 1123 * copy_path_name - copy src path to dst, possibly truncating 1124 * @dst: The destination buffer 1125 * @src: The source name 1126 * 1127 * returns number of bytes written (including trailing nul) 1128 */ 1129 int copy_path_name(char *dst, const char *src) 1130 { 1131 int name_len; 1132 1133 /* 1134 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it 1135 * will truncate and strlen(dst) will be PATH_MAX-1 1136 */ 1137 name_len = strscpy(dst, src, PATH_MAX); 1138 if (WARN_ON_ONCE(name_len < 0)) 1139 name_len = PATH_MAX-1; 1140 1141 /* we count the trailing nul */ 1142 name_len++; 1143 return name_len; 1144 } 1145 1146 struct super_cb_data { 1147 void *data; 1148 struct super_block *sb; 1149 }; 1150 1151 static void tcon_super_cb(struct super_block *sb, void *arg) 1152 { 1153 struct super_cb_data *sd = arg; 1154 struct cifs_sb_info *cifs_sb; 1155 struct cifs_tcon *t1 = sd->data, *t2; 1156 1157 if (sd->sb) 1158 return; 1159 1160 cifs_sb = CIFS_SB(sb); 1161 t2 = cifs_sb_master_tcon(cifs_sb); 1162 1163 spin_lock(&t2->tc_lock); 1164 if (t1->ses == t2->ses && 1165 t1->ses->server == t2->ses->server && 1166 t2->origin_fullpath && 1167 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) 1168 sd->sb = sb; 1169 spin_unlock(&t2->tc_lock); 1170 } 1171 1172 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), 1173 void *data) 1174 { 1175 struct super_cb_data sd = { 1176 .data = data, 1177 .sb = NULL, 1178 }; 1179 struct file_system_type **fs_type = (struct file_system_type *[]) { 1180 &cifs_fs_type, &smb3_fs_type, NULL, 1181 }; 1182 1183 for (; *fs_type; fs_type++) { 1184 iterate_supers_type(*fs_type, f, &sd); 1185 if (sd.sb) { 1186 /* 1187 * Grab an active reference in order to prevent automounts (DFS links) 1188 * of expiring and then freeing up our cifs superblock pointer while 1189 * we're doing failover. 1190 */ 1191 cifs_sb_active(sd.sb); 1192 return sd.sb; 1193 } 1194 } 1195 pr_warn_once("%s: could not find dfs superblock\n", __func__); 1196 return ERR_PTR(-EINVAL); 1197 } 1198 1199 static void __cifs_put_super(struct super_block *sb) 1200 { 1201 if (!IS_ERR_OR_NULL(sb)) 1202 cifs_sb_deactive(sb); 1203 } 1204 1205 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) 1206 { 1207 spin_lock(&tcon->tc_lock); 1208 if (!tcon->origin_fullpath) { 1209 spin_unlock(&tcon->tc_lock); 1210 return ERR_PTR(-ENOENT); 1211 } 1212 spin_unlock(&tcon->tc_lock); 1213 return __cifs_get_super(tcon_super_cb, tcon); 1214 } 1215 1216 void cifs_put_tcp_super(struct super_block *sb) 1217 { 1218 __cifs_put_super(sb); 1219 } 1220 1221 #ifdef CONFIG_CIFS_DFS_UPCALL 1222 int match_target_ip(struct TCP_Server_Info *server, 1223 const char *share, size_t share_len, 1224 bool *result) 1225 { 1226 int rc; 1227 char *target; 1228 struct sockaddr_storage ss; 1229 1230 *result = false; 1231 1232 target = kzalloc(share_len + 3, GFP_KERNEL); 1233 if (!target) 1234 return -ENOMEM; 1235 1236 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share); 1237 1238 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2); 1239 1240 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL); 1241 kfree(target); 1242 1243 if (rc < 0) 1244 return rc; 1245 1246 spin_lock(&server->srv_lock); 1247 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss); 1248 spin_unlock(&server->srv_lock); 1249 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result); 1250 return 0; 1251 } 1252 1253 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 1254 { 1255 int rc; 1256 1257 kfree(cifs_sb->prepath); 1258 cifs_sb->prepath = NULL; 1259 1260 if (prefix && *prefix) { 1261 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); 1262 if (IS_ERR(cifs_sb->prepath)) { 1263 rc = PTR_ERR(cifs_sb->prepath); 1264 cifs_sb->prepath = NULL; 1265 return rc; 1266 } 1267 if (cifs_sb->prepath) 1268 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); 1269 } 1270 1271 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; 1272 return 0; 1273 } 1274 1275 /* 1276 * Handle weird Windows SMB server behaviour. It responds with 1277 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for 1278 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains 1279 * non-ASCII unicode symbols. 1280 */ 1281 int cifs_inval_name_dfs_link_error(const unsigned int xid, 1282 struct cifs_tcon *tcon, 1283 struct cifs_sb_info *cifs_sb, 1284 const char *full_path, 1285 bool *islink) 1286 { 1287 struct cifs_ses *ses = tcon->ses; 1288 size_t len; 1289 char *path; 1290 char *ref_path; 1291 1292 *islink = false; 1293 1294 /* 1295 * Fast path - skip check when @full_path doesn't have a prefix path to 1296 * look up or tcon is not DFS. 1297 */ 1298 if (strlen(full_path) < 2 || !cifs_sb || 1299 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || 1300 !is_tcon_dfs(tcon)) 1301 return 0; 1302 1303 spin_lock(&tcon->tc_lock); 1304 if (!tcon->origin_fullpath) { 1305 spin_unlock(&tcon->tc_lock); 1306 return 0; 1307 } 1308 spin_unlock(&tcon->tc_lock); 1309 1310 /* 1311 * Slow path - tcon is DFS and @full_path has prefix path, so attempt 1312 * to get a referral to figure out whether it is an DFS link. 1313 */ 1314 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; 1315 path = kmalloc(len, GFP_KERNEL); 1316 if (!path) 1317 return -ENOMEM; 1318 1319 scnprintf(path, len, "%s%s", tcon->tree_name, full_path); 1320 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, 1321 cifs_remap(cifs_sb)); 1322 kfree(path); 1323 1324 if (IS_ERR(ref_path)) { 1325 if (PTR_ERR(ref_path) != -EINVAL) 1326 return PTR_ERR(ref_path); 1327 } else { 1328 struct dfs_info3_param *refs = NULL; 1329 int num_refs = 0; 1330 1331 /* 1332 * XXX: we are not using dfs_cache_find() here because we might 1333 * end up filling all the DFS cache and thus potentially 1334 * removing cached DFS targets that the client would eventually 1335 * need during failover. 1336 */ 1337 ses = CIFS_DFS_ROOT_SES(ses); 1338 if (ses->server->ops->get_dfs_refer && 1339 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, 1340 &num_refs, cifs_sb->local_nls, 1341 cifs_remap(cifs_sb))) 1342 *islink = refs[0].server_type == DFS_TYPE_LINK; 1343 free_dfs_info_array(refs, num_refs); 1344 kfree(ref_path); 1345 } 1346 return 0; 1347 } 1348 #endif 1349 1350 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) 1351 { 1352 int timeout = 10; 1353 int rc; 1354 1355 spin_lock(&server->srv_lock); 1356 if (server->tcpStatus != CifsNeedReconnect) { 1357 spin_unlock(&server->srv_lock); 1358 return 0; 1359 } 1360 timeout *= server->nr_targets; 1361 spin_unlock(&server->srv_lock); 1362 1363 /* 1364 * Give demultiplex thread up to 10 seconds to each target available for 1365 * reconnect -- should be greater than cifs socket timeout which is 7 1366 * seconds. 1367 * 1368 * On "soft" mounts we wait once. Hard mounts keep retrying until 1369 * process is killed or server comes back on-line. 1370 */ 1371 do { 1372 rc = wait_event_interruptible_timeout(server->response_q, 1373 (server->tcpStatus != CifsNeedReconnect), 1374 timeout * HZ); 1375 if (rc < 0) { 1376 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", 1377 __func__); 1378 return -ERESTARTSYS; 1379 } 1380 1381 /* are we still trying to reconnect? */ 1382 spin_lock(&server->srv_lock); 1383 if (server->tcpStatus != CifsNeedReconnect) { 1384 spin_unlock(&server->srv_lock); 1385 return 0; 1386 } 1387 spin_unlock(&server->srv_lock); 1388 } while (retry); 1389 1390 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); 1391 return -EHOSTDOWN; 1392 } 1393