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