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 extern mempool_t *cifs_sm_req_poolp; 31 extern mempool_t *cifs_req_poolp; 32 33 /* The xid serves as a useful identifier for each incoming vfs request, 34 in a similar way to the mid which is useful to track each sent smb, 35 and CurrentXid can also provide a running counter (although it 36 will eventually wrap past zero) of the total vfs operations handled 37 since the cifs fs was mounted */ 38 39 unsigned int 40 _get_xid(void) 41 { 42 unsigned int xid; 43 44 spin_lock(&GlobalMid_Lock); 45 GlobalTotalActiveXid++; 46 47 /* keep high water mark for number of simultaneous ops in filesystem */ 48 if (GlobalTotalActiveXid > GlobalMaxActiveXid) 49 GlobalMaxActiveXid = GlobalTotalActiveXid; 50 if (GlobalTotalActiveXid > 65000) 51 cifs_dbg(FYI, "warning: more than 65000 requests active\n"); 52 xid = GlobalCurrentXid++; 53 spin_unlock(&GlobalMid_Lock); 54 return xid; 55 } 56 57 void 58 _free_xid(unsigned int xid) 59 { 60 spin_lock(&GlobalMid_Lock); 61 /* if (GlobalTotalActiveXid == 0) 62 BUG(); */ 63 GlobalTotalActiveXid--; 64 spin_unlock(&GlobalMid_Lock); 65 } 66 67 struct cifs_ses * 68 sesInfoAlloc(void) 69 { 70 struct cifs_ses *ret_buf; 71 72 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL); 73 if (ret_buf) { 74 atomic_inc(&sesInfoAllocCount); 75 spin_lock_init(&ret_buf->ses_lock); 76 ret_buf->ses_status = SES_NEW; 77 ++ret_buf->ses_count; 78 INIT_LIST_HEAD(&ret_buf->smb_ses_list); 79 INIT_LIST_HEAD(&ret_buf->tcon_list); 80 mutex_init(&ret_buf->session_mutex); 81 spin_lock_init(&ret_buf->iface_lock); 82 INIT_LIST_HEAD(&ret_buf->iface_list); 83 spin_lock_init(&ret_buf->chan_lock); 84 } 85 return ret_buf; 86 } 87 88 void 89 sesInfoFree(struct cifs_ses *buf_to_free) 90 { 91 struct cifs_server_iface *iface = NULL, *niface = NULL; 92 93 if (buf_to_free == NULL) { 94 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n"); 95 return; 96 } 97 98 unload_nls(buf_to_free->local_nls); 99 atomic_dec(&sesInfoAllocCount); 100 kfree(buf_to_free->serverOS); 101 kfree(buf_to_free->serverDomain); 102 kfree(buf_to_free->serverNOS); 103 kfree_sensitive(buf_to_free->password); 104 kfree(buf_to_free->user_name); 105 kfree(buf_to_free->domainName); 106 kfree_sensitive(buf_to_free->auth_key.response); 107 spin_lock(&buf_to_free->iface_lock); 108 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list, 109 iface_head) 110 kref_put(&iface->refcount, release_iface); 111 spin_unlock(&buf_to_free->iface_lock); 112 kfree_sensitive(buf_to_free); 113 } 114 115 struct cifs_tcon * 116 tcon_info_alloc(bool dir_leases_enabled) 117 { 118 struct cifs_tcon *ret_buf; 119 120 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); 121 if (!ret_buf) 122 return NULL; 123 124 if (dir_leases_enabled == true) { 125 ret_buf->cfids = init_cached_dirs(); 126 if (!ret_buf->cfids) { 127 kfree(ret_buf); 128 return NULL; 129 } 130 } 131 /* else ret_buf->cfids is already set to NULL above */ 132 133 atomic_inc(&tconInfoAllocCount); 134 ret_buf->status = TID_NEW; 135 ++ret_buf->tc_count; 136 spin_lock_init(&ret_buf->tc_lock); 137 INIT_LIST_HEAD(&ret_buf->openFileList); 138 INIT_LIST_HEAD(&ret_buf->tcon_list); 139 spin_lock_init(&ret_buf->open_file_lock); 140 spin_lock_init(&ret_buf->stat_lock); 141 atomic_set(&ret_buf->num_local_opens, 0); 142 atomic_set(&ret_buf->num_remote_opens, 0); 143 ret_buf->stats_from_time = ktime_get_real_seconds(); 144 #ifdef CONFIG_CIFS_DFS_UPCALL 145 INIT_LIST_HEAD(&ret_buf->dfs_ses_list); 146 #endif 147 148 return ret_buf; 149 } 150 151 void 152 tconInfoFree(struct cifs_tcon *tcon) 153 { 154 if (tcon == NULL) { 155 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); 156 return; 157 } 158 free_cached_dirs(tcon->cfids); 159 atomic_dec(&tconInfoAllocCount); 160 kfree(tcon->nativeFileSystem); 161 kfree_sensitive(tcon->password); 162 #ifdef CONFIG_CIFS_DFS_UPCALL 163 dfs_put_root_smb_sessions(&tcon->dfs_ses_list); 164 #endif 165 kfree(tcon->origin_fullpath); 166 kfree(tcon); 167 } 168 169 struct smb_hdr * 170 cifs_buf_get(void) 171 { 172 struct smb_hdr *ret_buf = NULL; 173 /* 174 * SMB2 header is bigger than CIFS one - no problems to clean some 175 * more bytes for CIFS. 176 */ 177 size_t buf_size = sizeof(struct smb2_hdr); 178 179 /* 180 * We could use negotiated size instead of max_msgsize - 181 * but it may be more efficient to always alloc same size 182 * albeit slightly larger than necessary and maxbuffersize 183 * defaults to this and can not be bigger. 184 */ 185 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); 186 187 /* clear the first few header bytes */ 188 /* for most paths, more is cleared in header_assemble */ 189 memset(ret_buf, 0, buf_size + 3); 190 atomic_inc(&buf_alloc_count); 191 #ifdef CONFIG_CIFS_STATS2 192 atomic_inc(&total_buf_alloc_count); 193 #endif /* CONFIG_CIFS_STATS2 */ 194 195 return ret_buf; 196 } 197 198 void 199 cifs_buf_release(void *buf_to_free) 200 { 201 if (buf_to_free == NULL) { 202 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ 203 return; 204 } 205 mempool_free(buf_to_free, cifs_req_poolp); 206 207 atomic_dec(&buf_alloc_count); 208 return; 209 } 210 211 struct smb_hdr * 212 cifs_small_buf_get(void) 213 { 214 struct smb_hdr *ret_buf = NULL; 215 216 /* We could use negotiated size instead of max_msgsize - 217 but it may be more efficient to always alloc same size 218 albeit slightly larger than necessary and maxbuffersize 219 defaults to this and can not be bigger */ 220 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); 221 /* No need to clear memory here, cleared in header assemble */ 222 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ 223 atomic_inc(&small_buf_alloc_count); 224 #ifdef CONFIG_CIFS_STATS2 225 atomic_inc(&total_small_buf_alloc_count); 226 #endif /* CONFIG_CIFS_STATS2 */ 227 228 return ret_buf; 229 } 230 231 void 232 cifs_small_buf_release(void *buf_to_free) 233 { 234 235 if (buf_to_free == NULL) { 236 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); 237 return; 238 } 239 mempool_free(buf_to_free, cifs_sm_req_poolp); 240 241 atomic_dec(&small_buf_alloc_count); 242 return; 243 } 244 245 void 246 free_rsp_buf(int resp_buftype, void *rsp) 247 { 248 if (resp_buftype == CIFS_SMALL_BUFFER) 249 cifs_small_buf_release(rsp); 250 else if (resp_buftype == CIFS_LARGE_BUFFER) 251 cifs_buf_release(rsp); 252 } 253 254 /* NB: MID can not be set if treeCon not passed in, in that 255 case it is responsbility of caller to set the mid */ 256 void 257 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , 258 const struct cifs_tcon *treeCon, int word_count 259 /* length of fixed section (word count) in two byte units */) 260 { 261 char *temp = (char *) buffer; 262 263 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ 264 265 buffer->smb_buf_length = cpu_to_be32( 266 (2 * word_count) + sizeof(struct smb_hdr) - 267 4 /* RFC 1001 length field does not count */ + 268 2 /* for bcc field itself */) ; 269 270 buffer->Protocol[0] = 0xFF; 271 buffer->Protocol[1] = 'S'; 272 buffer->Protocol[2] = 'M'; 273 buffer->Protocol[3] = 'B'; 274 buffer->Command = smb_command; 275 buffer->Flags = 0x00; /* case sensitive */ 276 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; 277 buffer->Pid = cpu_to_le16((__u16)current->tgid); 278 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); 279 if (treeCon) { 280 buffer->Tid = treeCon->tid; 281 if (treeCon->ses) { 282 if (treeCon->ses->capabilities & CAP_UNICODE) 283 buffer->Flags2 |= SMBFLG2_UNICODE; 284 if (treeCon->ses->capabilities & CAP_STATUS32) 285 buffer->Flags2 |= SMBFLG2_ERR_STATUS; 286 287 /* Uid is not converted */ 288 buffer->Uid = treeCon->ses->Suid; 289 if (treeCon->ses->server) 290 buffer->Mid = get_next_mid(treeCon->ses->server); 291 } 292 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) 293 buffer->Flags2 |= SMBFLG2_DFS; 294 if (treeCon->nocase) 295 buffer->Flags |= SMBFLG_CASELESS; 296 if ((treeCon->ses) && (treeCon->ses->server)) 297 if (treeCon->ses->server->sign) 298 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; 299 } 300 301 /* endian conversion of flags is now done just before sending */ 302 buffer->WordCount = (char) word_count; 303 return; 304 } 305 306 static int 307 check_smb_hdr(struct smb_hdr *smb) 308 { 309 /* does it have the right SMB "signature" ? */ 310 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) { 311 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", 312 *(unsigned int *)smb->Protocol); 313 return 1; 314 } 315 316 /* if it's a response then accept */ 317 if (smb->Flags & SMBFLG_RESPONSE) 318 return 0; 319 320 /* only one valid case where server sends us request */ 321 if (smb->Command == SMB_COM_LOCKING_ANDX) 322 return 0; 323 324 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", 325 get_mid(smb)); 326 return 1; 327 } 328 329 int 330 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server) 331 { 332 struct smb_hdr *smb = (struct smb_hdr *)buf; 333 __u32 rfclen = be32_to_cpu(smb->smb_buf_length); 334 __u32 clc_len; /* calculated length */ 335 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", 336 total_read, rfclen); 337 338 /* is this frame too small to even get to a BCC? */ 339 if (total_read < 2 + sizeof(struct smb_hdr)) { 340 if ((total_read >= sizeof(struct smb_hdr) - 1) 341 && (smb->Status.CifsError != 0)) { 342 /* it's an error return */ 343 smb->WordCount = 0; 344 /* some error cases do not return wct and bcc */ 345 return 0; 346 } else if ((total_read == sizeof(struct smb_hdr) + 1) && 347 (smb->WordCount == 0)) { 348 char *tmp = (char *)smb; 349 /* Need to work around a bug in two servers here */ 350 /* First, check if the part of bcc they sent was zero */ 351 if (tmp[sizeof(struct smb_hdr)] == 0) { 352 /* some servers return only half of bcc 353 * on simple responses (wct, bcc both zero) 354 * in particular have seen this on 355 * ulogoffX and FindClose. This leaves 356 * one byte of bcc potentially unitialized 357 */ 358 /* zero rest of bcc */ 359 tmp[sizeof(struct smb_hdr)+1] = 0; 360 return 0; 361 } 362 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); 363 } else { 364 cifs_dbg(VFS, "Length less than smb header size\n"); 365 } 366 return -EIO; 367 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) { 368 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n", 369 __func__, smb->WordCount); 370 return -EIO; 371 } 372 373 /* otherwise, there is enough to get to the BCC */ 374 if (check_smb_hdr(smb)) 375 return -EIO; 376 clc_len = smbCalcSize(smb); 377 378 if (4 + rfclen != total_read) { 379 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n", 380 rfclen); 381 return -EIO; 382 } 383 384 if (4 + rfclen != clc_len) { 385 __u16 mid = get_mid(smb); 386 /* check if bcc wrapped around for large read responses */ 387 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { 388 /* check if lengths match mod 64K */ 389 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) 390 return 0; /* bcc wrapped */ 391 } 392 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", 393 clc_len, 4 + rfclen, mid); 394 395 if (4 + rfclen < clc_len) { 396 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", 397 rfclen, mid); 398 return -EIO; 399 } else if (rfclen > clc_len + 512) { 400 /* 401 * Some servers (Windows XP in particular) send more 402 * data than the lengths in the SMB packet would 403 * indicate on certain calls (byte range locks and 404 * trans2 find first calls in particular). While the 405 * client can handle such a frame by ignoring the 406 * trailing data, we choose limit the amount of extra 407 * data to 512 bytes. 408 */ 409 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", 410 rfclen, mid); 411 return -EIO; 412 } 413 } 414 return 0; 415 } 416 417 bool 418 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) 419 { 420 struct smb_hdr *buf = (struct smb_hdr *)buffer; 421 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; 422 struct TCP_Server_Info *pserver; 423 struct cifs_ses *ses; 424 struct cifs_tcon *tcon; 425 struct cifsInodeInfo *pCifsInode; 426 struct cifsFileInfo *netfile; 427 428 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); 429 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && 430 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { 431 struct smb_com_transaction_change_notify_rsp *pSMBr = 432 (struct smb_com_transaction_change_notify_rsp *)buf; 433 struct file_notify_information *pnotify; 434 __u32 data_offset = 0; 435 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length); 436 437 if (get_bcc(buf) > sizeof(struct file_notify_information)) { 438 data_offset = le32_to_cpu(pSMBr->DataOffset); 439 440 if (data_offset > 441 len - sizeof(struct file_notify_information)) { 442 cifs_dbg(FYI, "Invalid data_offset %u\n", 443 data_offset); 444 return true; 445 } 446 pnotify = (struct file_notify_information *) 447 ((char *)&pSMBr->hdr.Protocol + data_offset); 448 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", 449 pnotify->FileName, pnotify->Action); 450 /* cifs_dump_mem("Rcvd notify Data: ",buf, 451 sizeof(struct smb_hdr)+60); */ 452 return true; 453 } 454 if (pSMBr->hdr.Status.CifsError) { 455 cifs_dbg(FYI, "notify err 0x%x\n", 456 pSMBr->hdr.Status.CifsError); 457 return true; 458 } 459 return false; 460 } 461 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) 462 return false; 463 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { 464 /* no sense logging error on invalid handle on oplock 465 break - harmless race between close request and oplock 466 break response is expected from time to time writing out 467 large dirty files cached on the client */ 468 if ((NT_STATUS_INVALID_HANDLE) == 469 le32_to_cpu(pSMB->hdr.Status.CifsError)) { 470 cifs_dbg(FYI, "Invalid handle on oplock break\n"); 471 return true; 472 } else if (ERRbadfid == 473 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { 474 return true; 475 } else { 476 return false; /* on valid oplock brk we get "request" */ 477 } 478 } 479 if (pSMB->hdr.WordCount != 8) 480 return false; 481 482 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", 483 pSMB->LockType, pSMB->OplockLevel); 484 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) 485 return false; 486 487 /* If server is a channel, select the primary channel */ 488 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv; 489 490 /* look up tcon based on tid & uid */ 491 spin_lock(&cifs_tcp_ses_lock); 492 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 493 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 494 if (tcon->tid != buf->Tid) 495 continue; 496 497 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); 498 spin_lock(&tcon->open_file_lock); 499 list_for_each_entry(netfile, &tcon->openFileList, tlist) { 500 if (pSMB->Fid != netfile->fid.netfid) 501 continue; 502 503 cifs_dbg(FYI, "file id match, oplock break\n"); 504 pCifsInode = CIFS_I(d_inode(netfile->dentry)); 505 506 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, 507 &pCifsInode->flags); 508 509 netfile->oplock_epoch = 0; 510 netfile->oplock_level = pSMB->OplockLevel; 511 netfile->oplock_break_cancelled = false; 512 cifs_queue_oplock_break(netfile); 513 514 spin_unlock(&tcon->open_file_lock); 515 spin_unlock(&cifs_tcp_ses_lock); 516 return true; 517 } 518 spin_unlock(&tcon->open_file_lock); 519 spin_unlock(&cifs_tcp_ses_lock); 520 cifs_dbg(FYI, "No matching file for oplock break\n"); 521 return true; 522 } 523 } 524 spin_unlock(&cifs_tcp_ses_lock); 525 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); 526 return true; 527 } 528 529 void 530 dump_smb(void *buf, int smb_buf_length) 531 { 532 if (traceSMB == 0) 533 return; 534 535 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, 536 smb_buf_length, true); 537 } 538 539 void 540 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) 541 { 542 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 543 struct cifs_tcon *tcon = NULL; 544 545 if (cifs_sb->master_tlink) 546 tcon = cifs_sb_master_tcon(cifs_sb); 547 548 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 549 cifs_sb->mnt_cifs_serverino_autodisabled = true; 550 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n", 551 tcon ? tcon->tree_name : "new server"); 552 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n"); 553 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n"); 554 555 } 556 } 557 558 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) 559 { 560 oplock &= 0xF; 561 562 if (oplock == OPLOCK_EXCLUSIVE) { 563 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; 564 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", 565 &cinode->netfs.inode); 566 } else if (oplock == OPLOCK_READ) { 567 cinode->oplock = CIFS_CACHE_READ_FLG; 568 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", 569 &cinode->netfs.inode); 570 } else 571 cinode->oplock = 0; 572 } 573 574 /* 575 * We wait for oplock breaks to be processed before we attempt to perform 576 * writes. 577 */ 578 int cifs_get_writer(struct cifsInodeInfo *cinode) 579 { 580 int rc; 581 582 start: 583 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, 584 TASK_KILLABLE); 585 if (rc) 586 return rc; 587 588 spin_lock(&cinode->writers_lock); 589 if (!cinode->writers) 590 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 591 cinode->writers++; 592 /* Check to see if we have started servicing an oplock break */ 593 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { 594 cinode->writers--; 595 if (cinode->writers == 0) { 596 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 597 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 598 } 599 spin_unlock(&cinode->writers_lock); 600 goto start; 601 } 602 spin_unlock(&cinode->writers_lock); 603 return 0; 604 } 605 606 void cifs_put_writer(struct cifsInodeInfo *cinode) 607 { 608 spin_lock(&cinode->writers_lock); 609 cinode->writers--; 610 if (cinode->writers == 0) { 611 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 612 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 613 } 614 spin_unlock(&cinode->writers_lock); 615 } 616 617 /** 618 * cifs_queue_oplock_break - queue the oplock break handler for cfile 619 * @cfile: The file to break the oplock on 620 * 621 * This function is called from the demultiplex thread when it 622 * receives an oplock break for @cfile. 623 * 624 * Assumes the tcon->open_file_lock is held. 625 * Assumes cfile->file_info_lock is NOT held. 626 */ 627 void cifs_queue_oplock_break(struct cifsFileInfo *cfile) 628 { 629 /* 630 * Bump the handle refcount now while we hold the 631 * open_file_lock to enforce the validity of it for the oplock 632 * break handler. The matching put is done at the end of the 633 * handler. 634 */ 635 cifsFileInfo_get(cfile); 636 637 queue_work(cifsoplockd_wq, &cfile->oplock_break); 638 } 639 640 void cifs_done_oplock_break(struct cifsInodeInfo *cinode) 641 { 642 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); 643 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); 644 } 645 646 bool 647 backup_cred(struct cifs_sb_info *cifs_sb) 648 { 649 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { 650 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid())) 651 return true; 652 } 653 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { 654 if (in_group_p(cifs_sb->ctx->backupgid)) 655 return true; 656 } 657 658 return false; 659 } 660 661 void 662 cifs_del_pending_open(struct cifs_pending_open *open) 663 { 664 spin_lock(&tlink_tcon(open->tlink)->open_file_lock); 665 list_del(&open->olist); 666 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 667 } 668 669 void 670 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, 671 struct cifs_pending_open *open) 672 { 673 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); 674 open->oplock = CIFS_OPLOCK_NO_CHANGE; 675 open->tlink = tlink; 676 fid->pending_open = open; 677 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); 678 } 679 680 void 681 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, 682 struct cifs_pending_open *open) 683 { 684 spin_lock(&tlink_tcon(tlink)->open_file_lock); 685 cifs_add_pending_open_locked(fid, tlink, open); 686 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 687 } 688 689 /* 690 * Critical section which runs after acquiring deferred_lock. 691 * As there is no reference count on cifs_deferred_close, pdclose 692 * should not be used outside deferred_lock. 693 */ 694 bool 695 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) 696 { 697 struct cifs_deferred_close *dclose; 698 699 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) { 700 if ((dclose->netfid == cfile->fid.netfid) && 701 (dclose->persistent_fid == cfile->fid.persistent_fid) && 702 (dclose->volatile_fid == cfile->fid.volatile_fid)) { 703 *pdclose = dclose; 704 return true; 705 } 706 } 707 return false; 708 } 709 710 /* 711 * Critical section which runs after acquiring deferred_lock. 712 */ 713 void 714 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) 715 { 716 bool is_deferred = false; 717 struct cifs_deferred_close *pdclose; 718 719 is_deferred = cifs_is_deferred_close(cfile, &pdclose); 720 if (is_deferred) { 721 kfree(dclose); 722 return; 723 } 724 725 dclose->tlink = cfile->tlink; 726 dclose->netfid = cfile->fid.netfid; 727 dclose->persistent_fid = cfile->fid.persistent_fid; 728 dclose->volatile_fid = cfile->fid.volatile_fid; 729 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); 730 } 731 732 /* 733 * Critical section which runs after acquiring deferred_lock. 734 */ 735 void 736 cifs_del_deferred_close(struct cifsFileInfo *cfile) 737 { 738 bool is_deferred = false; 739 struct cifs_deferred_close *dclose; 740 741 is_deferred = cifs_is_deferred_close(cfile, &dclose); 742 if (!is_deferred) 743 return; 744 list_del(&dclose->dlist); 745 kfree(dclose); 746 } 747 748 void 749 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) 750 { 751 struct cifsFileInfo *cfile = NULL; 752 struct file_list *tmp_list, *tmp_next_list; 753 struct list_head file_head; 754 755 if (cifs_inode == NULL) 756 return; 757 758 INIT_LIST_HEAD(&file_head); 759 spin_lock(&cifs_inode->open_file_lock); 760 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { 761 if (delayed_work_pending(&cfile->deferred)) { 762 if (cancel_delayed_work(&cfile->deferred)) { 763 spin_lock(&cifs_inode->deferred_lock); 764 cifs_del_deferred_close(cfile); 765 spin_unlock(&cifs_inode->deferred_lock); 766 767 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 768 if (tmp_list == NULL) 769 break; 770 tmp_list->cfile = cfile; 771 list_add_tail(&tmp_list->list, &file_head); 772 } 773 } 774 } 775 spin_unlock(&cifs_inode->open_file_lock); 776 777 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 778 _cifsFileInfo_put(tmp_list->cfile, false, false); 779 list_del(&tmp_list->list); 780 kfree(tmp_list); 781 } 782 } 783 784 void 785 cifs_close_all_deferred_files(struct cifs_tcon *tcon) 786 { 787 struct cifsFileInfo *cfile; 788 struct file_list *tmp_list, *tmp_next_list; 789 struct list_head file_head; 790 791 INIT_LIST_HEAD(&file_head); 792 spin_lock(&tcon->open_file_lock); 793 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 794 if (delayed_work_pending(&cfile->deferred)) { 795 if (cancel_delayed_work(&cfile->deferred)) { 796 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 797 cifs_del_deferred_close(cfile); 798 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 799 800 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 801 if (tmp_list == NULL) 802 break; 803 tmp_list->cfile = cfile; 804 list_add_tail(&tmp_list->list, &file_head); 805 } 806 } 807 } 808 spin_unlock(&tcon->open_file_lock); 809 810 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 811 _cifsFileInfo_put(tmp_list->cfile, true, false); 812 list_del(&tmp_list->list); 813 kfree(tmp_list); 814 } 815 } 816 void 817 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path) 818 { 819 struct cifsFileInfo *cfile; 820 struct file_list *tmp_list, *tmp_next_list; 821 struct list_head file_head; 822 void *page; 823 const char *full_path; 824 825 INIT_LIST_HEAD(&file_head); 826 page = alloc_dentry_path(); 827 spin_lock(&tcon->open_file_lock); 828 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 829 full_path = build_path_from_dentry(cfile->dentry, page); 830 if (strstr(full_path, path)) { 831 if (delayed_work_pending(&cfile->deferred)) { 832 if (cancel_delayed_work(&cfile->deferred)) { 833 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 834 cifs_del_deferred_close(cfile); 835 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 836 837 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 838 if (tmp_list == NULL) 839 break; 840 tmp_list->cfile = cfile; 841 list_add_tail(&tmp_list->list, &file_head); 842 } 843 } 844 } 845 } 846 spin_unlock(&tcon->open_file_lock); 847 848 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 849 _cifsFileInfo_put(tmp_list->cfile, true, false); 850 list_del(&tmp_list->list); 851 kfree(tmp_list); 852 } 853 free_dentry_path(page); 854 } 855 856 /* 857 * If a dentry has been deleted, all corresponding open handles should know that 858 * so that we do not defer close them. 859 */ 860 void cifs_mark_open_handles_for_deleted_file(struct inode *inode, 861 const char *path) 862 { 863 struct cifsFileInfo *cfile; 864 void *page; 865 const char *full_path; 866 struct cifsInodeInfo *cinode = CIFS_I(inode); 867 868 page = alloc_dentry_path(); 869 spin_lock(&cinode->open_file_lock); 870 871 /* 872 * note: we need to construct path from dentry and compare only if the 873 * inode has any hardlinks. When number of hardlinks is 1, we can just 874 * mark all open handles since they are going to be from the same file. 875 */ 876 if (inode->i_nlink > 1) { 877 list_for_each_entry(cfile, &cinode->openFileList, flist) { 878 full_path = build_path_from_dentry(cfile->dentry, page); 879 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0) 880 cfile->status_file_deleted = true; 881 } 882 } else { 883 list_for_each_entry(cfile, &cinode->openFileList, flist) 884 cfile->status_file_deleted = true; 885 } 886 spin_unlock(&cinode->open_file_lock); 887 free_dentry_path(page); 888 } 889 890 /* parses DFS referral V3 structure 891 * caller is responsible for freeing target_nodes 892 * returns: 893 * - on success - 0 894 * - on failure - errno 895 */ 896 int 897 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size, 898 unsigned int *num_of_nodes, 899 struct dfs_info3_param **target_nodes, 900 const struct nls_table *nls_codepage, int remap, 901 const char *searchName, bool is_unicode) 902 { 903 int i, rc = 0; 904 char *data_end; 905 struct dfs_referral_level_3 *ref; 906 907 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals); 908 909 if (*num_of_nodes < 1) { 910 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n", 911 *num_of_nodes); 912 rc = -EINVAL; 913 goto parse_DFS_referrals_exit; 914 } 915 916 ref = (struct dfs_referral_level_3 *) &(rsp->referrals); 917 if (ref->VersionNumber != cpu_to_le16(3)) { 918 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n", 919 le16_to_cpu(ref->VersionNumber)); 920 rc = -EINVAL; 921 goto parse_DFS_referrals_exit; 922 } 923 924 /* get the upper boundary of the resp buffer */ 925 data_end = (char *)rsp + rsp_size; 926 927 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n", 928 *num_of_nodes, le32_to_cpu(rsp->DFSFlags)); 929 930 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param), 931 GFP_KERNEL); 932 if (*target_nodes == NULL) { 933 rc = -ENOMEM; 934 goto parse_DFS_referrals_exit; 935 } 936 937 /* collect necessary data from referrals */ 938 for (i = 0; i < *num_of_nodes; i++) { 939 char *temp; 940 int max_len; 941 struct dfs_info3_param *node = (*target_nodes)+i; 942 943 node->flags = le32_to_cpu(rsp->DFSFlags); 944 if (is_unicode) { 945 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2, 946 GFP_KERNEL); 947 if (tmp == NULL) { 948 rc = -ENOMEM; 949 goto parse_DFS_referrals_exit; 950 } 951 cifsConvertToUTF16((__le16 *) tmp, searchName, 952 PATH_MAX, nls_codepage, remap); 953 node->path_consumed = cifs_utf16_bytes(tmp, 954 le16_to_cpu(rsp->PathConsumed), 955 nls_codepage); 956 kfree(tmp); 957 } else 958 node->path_consumed = le16_to_cpu(rsp->PathConsumed); 959 960 node->server_type = le16_to_cpu(ref->ServerType); 961 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); 962 963 /* copy DfsPath */ 964 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset); 965 max_len = data_end - temp; 966 node->path_name = cifs_strndup_from_utf16(temp, max_len, 967 is_unicode, nls_codepage); 968 if (!node->path_name) { 969 rc = -ENOMEM; 970 goto parse_DFS_referrals_exit; 971 } 972 973 /* copy link target UNC */ 974 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset); 975 max_len = data_end - temp; 976 node->node_name = cifs_strndup_from_utf16(temp, max_len, 977 is_unicode, nls_codepage); 978 if (!node->node_name) { 979 rc = -ENOMEM; 980 goto parse_DFS_referrals_exit; 981 } 982 983 node->ttl = le32_to_cpu(ref->TimeToLive); 984 985 ref++; 986 } 987 988 parse_DFS_referrals_exit: 989 if (rc) { 990 free_dfs_info_array(*target_nodes, *num_of_nodes); 991 *target_nodes = NULL; 992 *num_of_nodes = 0; 993 } 994 return rc; 995 } 996 997 struct cifs_aio_ctx * 998 cifs_aio_ctx_alloc(void) 999 { 1000 struct cifs_aio_ctx *ctx; 1001 1002 /* 1003 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io 1004 * to false so that we know when we have to unreference pages within 1005 * cifs_aio_ctx_release() 1006 */ 1007 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL); 1008 if (!ctx) 1009 return NULL; 1010 1011 INIT_LIST_HEAD(&ctx->list); 1012 mutex_init(&ctx->aio_mutex); 1013 init_completion(&ctx->done); 1014 kref_init(&ctx->refcount); 1015 return ctx; 1016 } 1017 1018 void 1019 cifs_aio_ctx_release(struct kref *refcount) 1020 { 1021 struct cifs_aio_ctx *ctx = container_of(refcount, 1022 struct cifs_aio_ctx, refcount); 1023 1024 cifsFileInfo_put(ctx->cfile); 1025 1026 /* 1027 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly 1028 * which means that iov_iter_extract_pages() was a success and thus 1029 * that we may have references or pins on pages that we need to 1030 * release. 1031 */ 1032 if (ctx->bv) { 1033 if (ctx->should_dirty || ctx->bv_need_unpin) { 1034 unsigned int i; 1035 1036 for (i = 0; i < ctx->nr_pinned_pages; i++) { 1037 struct page *page = ctx->bv[i].bv_page; 1038 1039 if (ctx->should_dirty) 1040 set_page_dirty(page); 1041 if (ctx->bv_need_unpin) 1042 unpin_user_page(page); 1043 } 1044 } 1045 kvfree(ctx->bv); 1046 } 1047 1048 kfree(ctx); 1049 } 1050 1051 /** 1052 * cifs_alloc_hash - allocate hash and hash context together 1053 * @name: The name of the crypto hash algo 1054 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM 1055 * 1056 * The caller has to make sure @sdesc is initialized to either NULL or 1057 * a valid context. It can be freed via cifs_free_hash(). 1058 */ 1059 int 1060 cifs_alloc_hash(const char *name, struct shash_desc **sdesc) 1061 { 1062 int rc = 0; 1063 struct crypto_shash *alg = NULL; 1064 1065 if (*sdesc) 1066 return 0; 1067 1068 alg = crypto_alloc_shash(name, 0, 0); 1069 if (IS_ERR(alg)) { 1070 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name); 1071 rc = PTR_ERR(alg); 1072 *sdesc = NULL; 1073 return rc; 1074 } 1075 1076 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL); 1077 if (*sdesc == NULL) { 1078 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name); 1079 crypto_free_shash(alg); 1080 return -ENOMEM; 1081 } 1082 1083 (*sdesc)->tfm = alg; 1084 return 0; 1085 } 1086 1087 /** 1088 * cifs_free_hash - free hash and hash context together 1089 * @sdesc: Where to find the pointer to the hash TFM 1090 * 1091 * Freeing a NULL descriptor is safe. 1092 */ 1093 void 1094 cifs_free_hash(struct shash_desc **sdesc) 1095 { 1096 if (unlikely(!sdesc) || !*sdesc) 1097 return; 1098 1099 if ((*sdesc)->tfm) { 1100 crypto_free_shash((*sdesc)->tfm); 1101 (*sdesc)->tfm = NULL; 1102 } 1103 1104 kfree_sensitive(*sdesc); 1105 *sdesc = NULL; 1106 } 1107 1108 void extract_unc_hostname(const char *unc, const char **h, size_t *len) 1109 { 1110 const char *end; 1111 1112 /* skip initial slashes */ 1113 while (*unc && (*unc == '\\' || *unc == '/')) 1114 unc++; 1115 1116 end = unc; 1117 1118 while (*end && !(*end == '\\' || *end == '/')) 1119 end++; 1120 1121 *h = unc; 1122 *len = end - unc; 1123 } 1124 1125 /** 1126 * copy_path_name - copy src path to dst, possibly truncating 1127 * @dst: The destination buffer 1128 * @src: The source name 1129 * 1130 * returns number of bytes written (including trailing nul) 1131 */ 1132 int copy_path_name(char *dst, const char *src) 1133 { 1134 int name_len; 1135 1136 /* 1137 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it 1138 * will truncate and strlen(dst) will be PATH_MAX-1 1139 */ 1140 name_len = strscpy(dst, src, PATH_MAX); 1141 if (WARN_ON_ONCE(name_len < 0)) 1142 name_len = PATH_MAX-1; 1143 1144 /* we count the trailing nul */ 1145 name_len++; 1146 return name_len; 1147 } 1148 1149 struct super_cb_data { 1150 void *data; 1151 struct super_block *sb; 1152 }; 1153 1154 static void tcon_super_cb(struct super_block *sb, void *arg) 1155 { 1156 struct super_cb_data *sd = arg; 1157 struct cifs_sb_info *cifs_sb; 1158 struct cifs_tcon *t1 = sd->data, *t2; 1159 1160 if (sd->sb) 1161 return; 1162 1163 cifs_sb = CIFS_SB(sb); 1164 t2 = cifs_sb_master_tcon(cifs_sb); 1165 1166 spin_lock(&t2->tc_lock); 1167 if (t1->ses == t2->ses && 1168 t1->ses->server == t2->ses->server && 1169 t2->origin_fullpath && 1170 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) 1171 sd->sb = sb; 1172 spin_unlock(&t2->tc_lock); 1173 } 1174 1175 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), 1176 void *data) 1177 { 1178 struct super_cb_data sd = { 1179 .data = data, 1180 .sb = NULL, 1181 }; 1182 struct file_system_type **fs_type = (struct file_system_type *[]) { 1183 &cifs_fs_type, &smb3_fs_type, NULL, 1184 }; 1185 1186 for (; *fs_type; fs_type++) { 1187 iterate_supers_type(*fs_type, f, &sd); 1188 if (sd.sb) { 1189 /* 1190 * Grab an active reference in order to prevent automounts (DFS links) 1191 * of expiring and then freeing up our cifs superblock pointer while 1192 * we're doing failover. 1193 */ 1194 cifs_sb_active(sd.sb); 1195 return sd.sb; 1196 } 1197 } 1198 pr_warn_once("%s: could not find dfs superblock\n", __func__); 1199 return ERR_PTR(-EINVAL); 1200 } 1201 1202 static void __cifs_put_super(struct super_block *sb) 1203 { 1204 if (!IS_ERR_OR_NULL(sb)) 1205 cifs_sb_deactive(sb); 1206 } 1207 1208 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) 1209 { 1210 spin_lock(&tcon->tc_lock); 1211 if (!tcon->origin_fullpath) { 1212 spin_unlock(&tcon->tc_lock); 1213 return ERR_PTR(-ENOENT); 1214 } 1215 spin_unlock(&tcon->tc_lock); 1216 return __cifs_get_super(tcon_super_cb, tcon); 1217 } 1218 1219 void cifs_put_tcp_super(struct super_block *sb) 1220 { 1221 __cifs_put_super(sb); 1222 } 1223 1224 #ifdef CONFIG_CIFS_DFS_UPCALL 1225 int match_target_ip(struct TCP_Server_Info *server, 1226 const char *share, size_t share_len, 1227 bool *result) 1228 { 1229 int rc; 1230 char *target; 1231 struct sockaddr_storage ss; 1232 1233 *result = false; 1234 1235 target = kzalloc(share_len + 3, GFP_KERNEL); 1236 if (!target) 1237 return -ENOMEM; 1238 1239 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share); 1240 1241 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2); 1242 1243 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL); 1244 kfree(target); 1245 1246 if (rc < 0) 1247 return rc; 1248 1249 spin_lock(&server->srv_lock); 1250 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss); 1251 spin_unlock(&server->srv_lock); 1252 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result); 1253 return 0; 1254 } 1255 1256 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 1257 { 1258 int rc; 1259 1260 kfree(cifs_sb->prepath); 1261 cifs_sb->prepath = NULL; 1262 1263 if (prefix && *prefix) { 1264 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); 1265 if (IS_ERR(cifs_sb->prepath)) { 1266 rc = PTR_ERR(cifs_sb->prepath); 1267 cifs_sb->prepath = NULL; 1268 return rc; 1269 } 1270 if (cifs_sb->prepath) 1271 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); 1272 } 1273 1274 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; 1275 return 0; 1276 } 1277 1278 /* 1279 * Handle weird Windows SMB server behaviour. It responds with 1280 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for 1281 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains 1282 * non-ASCII unicode symbols. 1283 */ 1284 int cifs_inval_name_dfs_link_error(const unsigned int xid, 1285 struct cifs_tcon *tcon, 1286 struct cifs_sb_info *cifs_sb, 1287 const char *full_path, 1288 bool *islink) 1289 { 1290 struct cifs_ses *ses = tcon->ses; 1291 size_t len; 1292 char *path; 1293 char *ref_path; 1294 1295 *islink = false; 1296 1297 /* 1298 * Fast path - skip check when @full_path doesn't have a prefix path to 1299 * look up or tcon is not DFS. 1300 */ 1301 if (strlen(full_path) < 2 || !cifs_sb || 1302 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || 1303 !is_tcon_dfs(tcon)) 1304 return 0; 1305 1306 spin_lock(&tcon->tc_lock); 1307 if (!tcon->origin_fullpath) { 1308 spin_unlock(&tcon->tc_lock); 1309 return 0; 1310 } 1311 spin_unlock(&tcon->tc_lock); 1312 1313 /* 1314 * Slow path - tcon is DFS and @full_path has prefix path, so attempt 1315 * to get a referral to figure out whether it is an DFS link. 1316 */ 1317 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; 1318 path = kmalloc(len, GFP_KERNEL); 1319 if (!path) 1320 return -ENOMEM; 1321 1322 scnprintf(path, len, "%s%s", tcon->tree_name, full_path); 1323 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, 1324 cifs_remap(cifs_sb)); 1325 kfree(path); 1326 1327 if (IS_ERR(ref_path)) { 1328 if (PTR_ERR(ref_path) != -EINVAL) 1329 return PTR_ERR(ref_path); 1330 } else { 1331 struct dfs_info3_param *refs = NULL; 1332 int num_refs = 0; 1333 1334 /* 1335 * XXX: we are not using dfs_cache_find() here because we might 1336 * end up filling all the DFS cache and thus potentially 1337 * removing cached DFS targets that the client would eventually 1338 * need during failover. 1339 */ 1340 ses = CIFS_DFS_ROOT_SES(ses); 1341 if (ses->server->ops->get_dfs_refer && 1342 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, 1343 &num_refs, cifs_sb->local_nls, 1344 cifs_remap(cifs_sb))) 1345 *islink = refs[0].server_type == DFS_TYPE_LINK; 1346 free_dfs_info_array(refs, num_refs); 1347 kfree(ref_path); 1348 } 1349 return 0; 1350 } 1351 #endif 1352 1353 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) 1354 { 1355 int timeout = 10; 1356 int rc; 1357 1358 spin_lock(&server->srv_lock); 1359 if (server->tcpStatus != CifsNeedReconnect) { 1360 spin_unlock(&server->srv_lock); 1361 return 0; 1362 } 1363 timeout *= server->nr_targets; 1364 spin_unlock(&server->srv_lock); 1365 1366 /* 1367 * Give demultiplex thread up to 10 seconds to each target available for 1368 * reconnect -- should be greater than cifs socket timeout which is 7 1369 * seconds. 1370 * 1371 * On "soft" mounts we wait once. Hard mounts keep retrying until 1372 * process is killed or server comes back on-line. 1373 */ 1374 do { 1375 rc = wait_event_interruptible_timeout(server->response_q, 1376 (server->tcpStatus != CifsNeedReconnect), 1377 timeout * HZ); 1378 if (rc < 0) { 1379 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", 1380 __func__); 1381 return -ERESTARTSYS; 1382 } 1383 1384 /* are we still trying to reconnect? */ 1385 spin_lock(&server->srv_lock); 1386 if (server->tcpStatus != CifsNeedReconnect) { 1387 spin_unlock(&server->srv_lock); 1388 return 0; 1389 } 1390 spin_unlock(&server->srv_lock); 1391 } while (retry); 1392 1393 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); 1394 return -EHOSTDOWN; 1395 } 1396