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, enum smb3_tcon_ref_trace trace) 115 { 116 struct cifs_tcon *ret_buf; 117 static atomic_t tcon_debug_id; 118 119 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); 120 if (!ret_buf) 121 return NULL; 122 123 if (dir_leases_enabled == true) { 124 ret_buf->cfids = init_cached_dirs(); 125 if (!ret_buf->cfids) { 126 kfree(ret_buf); 127 return NULL; 128 } 129 } 130 /* else ret_buf->cfids is already set to NULL above */ 131 132 atomic_inc(&tconInfoAllocCount); 133 ret_buf->status = TID_NEW; 134 ret_buf->debug_id = atomic_inc_return(&tcon_debug_id); 135 ret_buf->tc_count = 1; 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_FSCACHE 145 mutex_init(&ret_buf->fscache_lock); 146 #endif 147 trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace); 148 #ifdef CONFIG_CIFS_DFS_UPCALL 149 INIT_LIST_HEAD(&ret_buf->dfs_ses_list); 150 #endif 151 152 return ret_buf; 153 } 154 155 void 156 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace) 157 { 158 if (tcon == NULL) { 159 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); 160 return; 161 } 162 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace); 163 free_cached_dirs(tcon->cfids); 164 atomic_dec(&tconInfoAllocCount); 165 kfree(tcon->nativeFileSystem); 166 kfree_sensitive(tcon->password); 167 kfree(tcon->origin_fullpath); 168 kfree(tcon); 169 } 170 171 struct smb_hdr * 172 cifs_buf_get(void) 173 { 174 struct smb_hdr *ret_buf = NULL; 175 /* 176 * SMB2 header is bigger than CIFS one - no problems to clean some 177 * more bytes for CIFS. 178 */ 179 size_t buf_size = sizeof(struct smb2_hdr); 180 181 /* 182 * We could use negotiated size instead of max_msgsize - 183 * but it may be more efficient to always alloc same size 184 * albeit slightly larger than necessary and maxbuffersize 185 * defaults to this and can not be bigger. 186 */ 187 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); 188 189 /* clear the first few header bytes */ 190 /* for most paths, more is cleared in header_assemble */ 191 memset(ret_buf, 0, buf_size + 3); 192 atomic_inc(&buf_alloc_count); 193 #ifdef CONFIG_CIFS_STATS2 194 atomic_inc(&total_buf_alloc_count); 195 #endif /* CONFIG_CIFS_STATS2 */ 196 197 return ret_buf; 198 } 199 200 void 201 cifs_buf_release(void *buf_to_free) 202 { 203 if (buf_to_free == NULL) { 204 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ 205 return; 206 } 207 mempool_free(buf_to_free, cifs_req_poolp); 208 209 atomic_dec(&buf_alloc_count); 210 return; 211 } 212 213 struct smb_hdr * 214 cifs_small_buf_get(void) 215 { 216 struct smb_hdr *ret_buf = NULL; 217 218 /* We could use negotiated size instead of max_msgsize - 219 but it may be more efficient to always alloc same size 220 albeit slightly larger than necessary and maxbuffersize 221 defaults to this and can not be bigger */ 222 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); 223 /* No need to clear memory here, cleared in header assemble */ 224 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ 225 atomic_inc(&small_buf_alloc_count); 226 #ifdef CONFIG_CIFS_STATS2 227 atomic_inc(&total_small_buf_alloc_count); 228 #endif /* CONFIG_CIFS_STATS2 */ 229 230 return ret_buf; 231 } 232 233 void 234 cifs_small_buf_release(void *buf_to_free) 235 { 236 237 if (buf_to_free == NULL) { 238 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); 239 return; 240 } 241 mempool_free(buf_to_free, cifs_sm_req_poolp); 242 243 atomic_dec(&small_buf_alloc_count); 244 return; 245 } 246 247 void 248 free_rsp_buf(int resp_buftype, void *rsp) 249 { 250 if (resp_buftype == CIFS_SMALL_BUFFER) 251 cifs_small_buf_release(rsp); 252 else if (resp_buftype == CIFS_LARGE_BUFFER) 253 cifs_buf_release(rsp); 254 } 255 256 /* NB: MID can not be set if treeCon not passed in, in that 257 case it is responsibility of caller to set the mid */ 258 void 259 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , 260 const struct cifs_tcon *treeCon, int word_count 261 /* length of fixed section (word count) in two byte units */) 262 { 263 char *temp = (char *) buffer; 264 265 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ 266 267 buffer->smb_buf_length = cpu_to_be32( 268 (2 * word_count) + sizeof(struct smb_hdr) - 269 4 /* RFC 1001 length field does not count */ + 270 2 /* for bcc field itself */) ; 271 272 buffer->Protocol[0] = 0xFF; 273 buffer->Protocol[1] = 'S'; 274 buffer->Protocol[2] = 'M'; 275 buffer->Protocol[3] = 'B'; 276 buffer->Command = smb_command; 277 buffer->Flags = 0x00; /* case sensitive */ 278 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; 279 buffer->Pid = cpu_to_le16((__u16)current->tgid); 280 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); 281 if (treeCon) { 282 buffer->Tid = treeCon->tid; 283 if (treeCon->ses) { 284 if (treeCon->ses->capabilities & CAP_UNICODE) 285 buffer->Flags2 |= SMBFLG2_UNICODE; 286 if (treeCon->ses->capabilities & CAP_STATUS32) 287 buffer->Flags2 |= SMBFLG2_ERR_STATUS; 288 289 /* Uid is not converted */ 290 buffer->Uid = treeCon->ses->Suid; 291 if (treeCon->ses->server) 292 buffer->Mid = get_next_mid(treeCon->ses->server); 293 } 294 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) 295 buffer->Flags2 |= SMBFLG2_DFS; 296 if (treeCon->nocase) 297 buffer->Flags |= SMBFLG_CASELESS; 298 if ((treeCon->ses) && (treeCon->ses->server)) 299 if (treeCon->ses->server->sign) 300 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; 301 } 302 303 /* endian conversion of flags is now done just before sending */ 304 buffer->WordCount = (char) word_count; 305 return; 306 } 307 308 static int 309 check_smb_hdr(struct smb_hdr *smb) 310 { 311 /* does it have the right SMB "signature" ? */ 312 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) { 313 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", 314 *(unsigned int *)smb->Protocol); 315 return 1; 316 } 317 318 /* if it's a response then accept */ 319 if (smb->Flags & SMBFLG_RESPONSE) 320 return 0; 321 322 /* only one valid case where server sends us request */ 323 if (smb->Command == SMB_COM_LOCKING_ANDX) 324 return 0; 325 326 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", 327 get_mid(smb)); 328 return 1; 329 } 330 331 int 332 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server) 333 { 334 struct smb_hdr *smb = (struct smb_hdr *)buf; 335 __u32 rfclen = be32_to_cpu(smb->smb_buf_length); 336 __u32 clc_len; /* calculated length */ 337 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", 338 total_read, rfclen); 339 340 /* is this frame too small to even get to a BCC? */ 341 if (total_read < 2 + sizeof(struct smb_hdr)) { 342 if ((total_read >= sizeof(struct smb_hdr) - 1) 343 && (smb->Status.CifsError != 0)) { 344 /* it's an error return */ 345 smb->WordCount = 0; 346 /* some error cases do not return wct and bcc */ 347 return 0; 348 } else if ((total_read == sizeof(struct smb_hdr) + 1) && 349 (smb->WordCount == 0)) { 350 char *tmp = (char *)smb; 351 /* Need to work around a bug in two servers here */ 352 /* First, check if the part of bcc they sent was zero */ 353 if (tmp[sizeof(struct smb_hdr)] == 0) { 354 /* some servers return only half of bcc 355 * on simple responses (wct, bcc both zero) 356 * in particular have seen this on 357 * ulogoffX and FindClose. This leaves 358 * one byte of bcc potentially uninitialized 359 */ 360 /* zero rest of bcc */ 361 tmp[sizeof(struct smb_hdr)+1] = 0; 362 return 0; 363 } 364 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); 365 } else { 366 cifs_dbg(VFS, "Length less than smb header size\n"); 367 } 368 return -EIO; 369 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) { 370 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n", 371 __func__, smb->WordCount); 372 return -EIO; 373 } 374 375 /* otherwise, there is enough to get to the BCC */ 376 if (check_smb_hdr(smb)) 377 return -EIO; 378 clc_len = smbCalcSize(smb); 379 380 if (4 + rfclen != total_read) { 381 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n", 382 rfclen); 383 return -EIO; 384 } 385 386 if (4 + rfclen != clc_len) { 387 __u16 mid = get_mid(smb); 388 /* check if bcc wrapped around for large read responses */ 389 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { 390 /* check if lengths match mod 64K */ 391 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) 392 return 0; /* bcc wrapped */ 393 } 394 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", 395 clc_len, 4 + rfclen, mid); 396 397 if (4 + rfclen < clc_len) { 398 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", 399 rfclen, mid); 400 return -EIO; 401 } else if (rfclen > clc_len + 512) { 402 /* 403 * Some servers (Windows XP in particular) send more 404 * data than the lengths in the SMB packet would 405 * indicate on certain calls (byte range locks and 406 * trans2 find first calls in particular). While the 407 * client can handle such a frame by ignoring the 408 * trailing data, we choose limit the amount of extra 409 * data to 512 bytes. 410 */ 411 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", 412 rfclen, mid); 413 return -EIO; 414 } 415 } 416 return 0; 417 } 418 419 bool 420 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) 421 { 422 struct smb_hdr *buf = (struct smb_hdr *)buffer; 423 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; 424 struct TCP_Server_Info *pserver; 425 struct cifs_ses *ses; 426 struct cifs_tcon *tcon; 427 struct cifsInodeInfo *pCifsInode; 428 struct cifsFileInfo *netfile; 429 430 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); 431 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && 432 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { 433 struct smb_com_transaction_change_notify_rsp *pSMBr = 434 (struct smb_com_transaction_change_notify_rsp *)buf; 435 struct file_notify_information *pnotify; 436 __u32 data_offset = 0; 437 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length); 438 439 if (get_bcc(buf) > sizeof(struct file_notify_information)) { 440 data_offset = le32_to_cpu(pSMBr->DataOffset); 441 442 if (data_offset > 443 len - sizeof(struct file_notify_information)) { 444 cifs_dbg(FYI, "Invalid data_offset %u\n", 445 data_offset); 446 return true; 447 } 448 pnotify = (struct file_notify_information *) 449 ((char *)&pSMBr->hdr.Protocol + data_offset); 450 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", 451 pnotify->FileName, pnotify->Action); 452 /* cifs_dump_mem("Rcvd notify Data: ",buf, 453 sizeof(struct smb_hdr)+60); */ 454 return true; 455 } 456 if (pSMBr->hdr.Status.CifsError) { 457 cifs_dbg(FYI, "notify err 0x%x\n", 458 pSMBr->hdr.Status.CifsError); 459 return true; 460 } 461 return false; 462 } 463 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) 464 return false; 465 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { 466 /* no sense logging error on invalid handle on oplock 467 break - harmless race between close request and oplock 468 break response is expected from time to time writing out 469 large dirty files cached on the client */ 470 if ((NT_STATUS_INVALID_HANDLE) == 471 le32_to_cpu(pSMB->hdr.Status.CifsError)) { 472 cifs_dbg(FYI, "Invalid handle on oplock break\n"); 473 return true; 474 } else if (ERRbadfid == 475 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { 476 return true; 477 } else { 478 return false; /* on valid oplock brk we get "request" */ 479 } 480 } 481 if (pSMB->hdr.WordCount != 8) 482 return false; 483 484 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", 485 pSMB->LockType, pSMB->OplockLevel); 486 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) 487 return false; 488 489 /* If server is a channel, select the primary channel */ 490 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv; 491 492 /* look up tcon based on tid & uid */ 493 spin_lock(&cifs_tcp_ses_lock); 494 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 495 if (cifs_ses_exiting(ses)) 496 continue; 497 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 498 if (tcon->tid != buf->Tid) 499 continue; 500 501 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); 502 spin_lock(&tcon->open_file_lock); 503 list_for_each_entry(netfile, &tcon->openFileList, tlist) { 504 if (pSMB->Fid != netfile->fid.netfid) 505 continue; 506 507 cifs_dbg(FYI, "file id match, oplock break\n"); 508 pCifsInode = CIFS_I(d_inode(netfile->dentry)); 509 510 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, 511 &pCifsInode->flags); 512 513 netfile->oplock_epoch = 0; 514 netfile->oplock_level = pSMB->OplockLevel; 515 netfile->oplock_break_cancelled = false; 516 cifs_queue_oplock_break(netfile); 517 518 spin_unlock(&tcon->open_file_lock); 519 spin_unlock(&cifs_tcp_ses_lock); 520 return true; 521 } 522 spin_unlock(&tcon->open_file_lock); 523 spin_unlock(&cifs_tcp_ses_lock); 524 cifs_dbg(FYI, "No matching file for oplock break\n"); 525 return true; 526 } 527 } 528 spin_unlock(&cifs_tcp_ses_lock); 529 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); 530 return true; 531 } 532 533 void 534 dump_smb(void *buf, int smb_buf_length) 535 { 536 if (traceSMB == 0) 537 return; 538 539 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, 540 smb_buf_length, true); 541 } 542 543 void 544 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) 545 { 546 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 547 struct cifs_tcon *tcon = NULL; 548 549 if (cifs_sb->master_tlink) 550 tcon = cifs_sb_master_tcon(cifs_sb); 551 552 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 553 cifs_sb->mnt_cifs_serverino_autodisabled = true; 554 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n", 555 tcon ? tcon->tree_name : "new server"); 556 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n"); 557 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n"); 558 559 } 560 } 561 562 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) 563 { 564 oplock &= 0xF; 565 566 if (oplock == OPLOCK_EXCLUSIVE) { 567 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; 568 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", 569 &cinode->netfs.inode); 570 } else if (oplock == OPLOCK_READ) { 571 cinode->oplock = CIFS_CACHE_READ_FLG; 572 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", 573 &cinode->netfs.inode); 574 } else 575 cinode->oplock = 0; 576 } 577 578 /* 579 * We wait for oplock breaks to be processed before we attempt to perform 580 * writes. 581 */ 582 int cifs_get_writer(struct cifsInodeInfo *cinode) 583 { 584 int rc; 585 586 start: 587 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, 588 TASK_KILLABLE); 589 if (rc) 590 return rc; 591 592 spin_lock(&cinode->writers_lock); 593 if (!cinode->writers) 594 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 595 cinode->writers++; 596 /* Check to see if we have started servicing an oplock break */ 597 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { 598 cinode->writers--; 599 if (cinode->writers == 0) { 600 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 601 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 602 } 603 spin_unlock(&cinode->writers_lock); 604 goto start; 605 } 606 spin_unlock(&cinode->writers_lock); 607 return 0; 608 } 609 610 void cifs_put_writer(struct cifsInodeInfo *cinode) 611 { 612 spin_lock(&cinode->writers_lock); 613 cinode->writers--; 614 if (cinode->writers == 0) { 615 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 616 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 617 } 618 spin_unlock(&cinode->writers_lock); 619 } 620 621 /** 622 * cifs_queue_oplock_break - queue the oplock break handler for cfile 623 * @cfile: The file to break the oplock on 624 * 625 * This function is called from the demultiplex thread when it 626 * receives an oplock break for @cfile. 627 * 628 * Assumes the tcon->open_file_lock is held. 629 * Assumes cfile->file_info_lock is NOT held. 630 */ 631 void cifs_queue_oplock_break(struct cifsFileInfo *cfile) 632 { 633 /* 634 * Bump the handle refcount now while we hold the 635 * open_file_lock to enforce the validity of it for the oplock 636 * break handler. The matching put is done at the end of the 637 * handler. 638 */ 639 cifsFileInfo_get(cfile); 640 641 queue_work(cifsoplockd_wq, &cfile->oplock_break); 642 } 643 644 void cifs_done_oplock_break(struct cifsInodeInfo *cinode) 645 { 646 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); 647 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); 648 } 649 650 bool 651 backup_cred(struct cifs_sb_info *cifs_sb) 652 { 653 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { 654 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid())) 655 return true; 656 } 657 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { 658 if (in_group_p(cifs_sb->ctx->backupgid)) 659 return true; 660 } 661 662 return false; 663 } 664 665 void 666 cifs_del_pending_open(struct cifs_pending_open *open) 667 { 668 spin_lock(&tlink_tcon(open->tlink)->open_file_lock); 669 list_del(&open->olist); 670 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 671 } 672 673 void 674 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, 675 struct cifs_pending_open *open) 676 { 677 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); 678 open->oplock = CIFS_OPLOCK_NO_CHANGE; 679 open->tlink = tlink; 680 fid->pending_open = open; 681 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); 682 } 683 684 void 685 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, 686 struct cifs_pending_open *open) 687 { 688 spin_lock(&tlink_tcon(tlink)->open_file_lock); 689 cifs_add_pending_open_locked(fid, tlink, open); 690 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 691 } 692 693 /* 694 * Critical section which runs after acquiring deferred_lock. 695 * As there is no reference count on cifs_deferred_close, pdclose 696 * should not be used outside deferred_lock. 697 */ 698 bool 699 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) 700 { 701 struct cifs_deferred_close *dclose; 702 703 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) { 704 if ((dclose->netfid == cfile->fid.netfid) && 705 (dclose->persistent_fid == cfile->fid.persistent_fid) && 706 (dclose->volatile_fid == cfile->fid.volatile_fid)) { 707 *pdclose = dclose; 708 return true; 709 } 710 } 711 return false; 712 } 713 714 /* 715 * Critical section which runs after acquiring deferred_lock. 716 */ 717 void 718 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) 719 { 720 bool is_deferred = false; 721 struct cifs_deferred_close *pdclose; 722 723 is_deferred = cifs_is_deferred_close(cfile, &pdclose); 724 if (is_deferred) { 725 kfree(dclose); 726 return; 727 } 728 729 dclose->tlink = cfile->tlink; 730 dclose->netfid = cfile->fid.netfid; 731 dclose->persistent_fid = cfile->fid.persistent_fid; 732 dclose->volatile_fid = cfile->fid.volatile_fid; 733 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); 734 } 735 736 /* 737 * Critical section which runs after acquiring deferred_lock. 738 */ 739 void 740 cifs_del_deferred_close(struct cifsFileInfo *cfile) 741 { 742 bool is_deferred = false; 743 struct cifs_deferred_close *dclose; 744 745 is_deferred = cifs_is_deferred_close(cfile, &dclose); 746 if (!is_deferred) 747 return; 748 list_del(&dclose->dlist); 749 kfree(dclose); 750 } 751 752 void 753 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) 754 { 755 struct cifsFileInfo *cfile = NULL; 756 struct file_list *tmp_list, *tmp_next_list; 757 LIST_HEAD(file_head); 758 759 if (cifs_inode == NULL) 760 return; 761 762 spin_lock(&cifs_inode->open_file_lock); 763 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { 764 if (delayed_work_pending(&cfile->deferred)) { 765 if (cancel_delayed_work(&cfile->deferred)) { 766 spin_lock(&cifs_inode->deferred_lock); 767 cifs_del_deferred_close(cfile); 768 spin_unlock(&cifs_inode->deferred_lock); 769 770 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 771 if (tmp_list == NULL) 772 break; 773 tmp_list->cfile = cfile; 774 list_add_tail(&tmp_list->list, &file_head); 775 } 776 } 777 } 778 spin_unlock(&cifs_inode->open_file_lock); 779 780 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 781 _cifsFileInfo_put(tmp_list->cfile, false, false); 782 list_del(&tmp_list->list); 783 kfree(tmp_list); 784 } 785 } 786 787 void 788 cifs_close_all_deferred_files(struct cifs_tcon *tcon) 789 { 790 struct cifsFileInfo *cfile; 791 struct file_list *tmp_list, *tmp_next_list; 792 LIST_HEAD(file_head); 793 794 spin_lock(&tcon->open_file_lock); 795 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 796 if (delayed_work_pending(&cfile->deferred)) { 797 if (cancel_delayed_work(&cfile->deferred)) { 798 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 799 cifs_del_deferred_close(cfile); 800 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 801 802 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 803 if (tmp_list == NULL) 804 break; 805 tmp_list->cfile = cfile; 806 list_add_tail(&tmp_list->list, &file_head); 807 } 808 } 809 } 810 spin_unlock(&tcon->open_file_lock); 811 812 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 813 _cifsFileInfo_put(tmp_list->cfile, true, false); 814 list_del(&tmp_list->list); 815 kfree(tmp_list); 816 } 817 } 818 void 819 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path) 820 { 821 struct cifsFileInfo *cfile; 822 struct file_list *tmp_list, *tmp_next_list; 823 void *page; 824 const char *full_path; 825 LIST_HEAD(file_head); 826 827 page = alloc_dentry_path(); 828 spin_lock(&tcon->open_file_lock); 829 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 830 full_path = build_path_from_dentry(cfile->dentry, page); 831 if (strstr(full_path, path)) { 832 if (delayed_work_pending(&cfile->deferred)) { 833 if (cancel_delayed_work(&cfile->deferred)) { 834 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 835 cifs_del_deferred_close(cfile); 836 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 837 838 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 839 if (tmp_list == NULL) 840 break; 841 tmp_list->cfile = cfile; 842 list_add_tail(&tmp_list->list, &file_head); 843 } 844 } 845 } 846 } 847 spin_unlock(&tcon->open_file_lock); 848 849 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 850 _cifsFileInfo_put(tmp_list->cfile, true, false); 851 list_del(&tmp_list->list); 852 kfree(tmp_list); 853 } 854 free_dentry_path(page); 855 } 856 857 /* 858 * If a dentry has been deleted, all corresponding open handles should know that 859 * so that we do not defer close them. 860 */ 861 void cifs_mark_open_handles_for_deleted_file(struct inode *inode, 862 const char *path) 863 { 864 struct cifsFileInfo *cfile; 865 void *page; 866 const char *full_path; 867 struct cifsInodeInfo *cinode = CIFS_I(inode); 868 869 page = alloc_dentry_path(); 870 spin_lock(&cinode->open_file_lock); 871 872 /* 873 * note: we need to construct path from dentry and compare only if the 874 * inode has any hardlinks. When number of hardlinks is 1, we can just 875 * mark all open handles since they are going to be from the same file. 876 */ 877 if (inode->i_nlink > 1) { 878 list_for_each_entry(cfile, &cinode->openFileList, flist) { 879 full_path = build_path_from_dentry(cfile->dentry, page); 880 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0) 881 cfile->status_file_deleted = true; 882 } 883 } else { 884 list_for_each_entry(cfile, &cinode->openFileList, flist) 885 cfile->status_file_deleted = true; 886 } 887 spin_unlock(&cinode->open_file_lock); 888 free_dentry_path(page); 889 } 890 891 /* parses DFS referral V3 structure 892 * caller is responsible for freeing target_nodes 893 * returns: 894 * - on success - 0 895 * - on failure - errno 896 */ 897 int 898 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size, 899 unsigned int *num_of_nodes, 900 struct dfs_info3_param **target_nodes, 901 const struct nls_table *nls_codepage, int remap, 902 const char *searchName, bool is_unicode) 903 { 904 int i, rc = 0; 905 char *data_end; 906 struct dfs_referral_level_3 *ref; 907 908 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals); 909 910 if (*num_of_nodes < 1) { 911 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n", 912 *num_of_nodes); 913 rc = -EINVAL; 914 goto parse_DFS_referrals_exit; 915 } 916 917 ref = (struct dfs_referral_level_3 *) &(rsp->referrals); 918 if (ref->VersionNumber != cpu_to_le16(3)) { 919 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n", 920 le16_to_cpu(ref->VersionNumber)); 921 rc = -EINVAL; 922 goto parse_DFS_referrals_exit; 923 } 924 925 /* get the upper boundary of the resp buffer */ 926 data_end = (char *)rsp + rsp_size; 927 928 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n", 929 *num_of_nodes, le32_to_cpu(rsp->DFSFlags)); 930 931 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param), 932 GFP_KERNEL); 933 if (*target_nodes == NULL) { 934 rc = -ENOMEM; 935 goto parse_DFS_referrals_exit; 936 } 937 938 /* collect necessary data from referrals */ 939 for (i = 0; i < *num_of_nodes; i++) { 940 char *temp; 941 int max_len; 942 struct dfs_info3_param *node = (*target_nodes)+i; 943 944 node->flags = le32_to_cpu(rsp->DFSFlags); 945 if (is_unicode) { 946 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2, 947 GFP_KERNEL); 948 if (tmp == NULL) { 949 rc = -ENOMEM; 950 goto parse_DFS_referrals_exit; 951 } 952 cifsConvertToUTF16((__le16 *) tmp, searchName, 953 PATH_MAX, nls_codepage, remap); 954 node->path_consumed = cifs_utf16_bytes(tmp, 955 le16_to_cpu(rsp->PathConsumed), 956 nls_codepage); 957 kfree(tmp); 958 } else 959 node->path_consumed = le16_to_cpu(rsp->PathConsumed); 960 961 node->server_type = le16_to_cpu(ref->ServerType); 962 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); 963 964 /* copy DfsPath */ 965 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset); 966 max_len = data_end - temp; 967 node->path_name = cifs_strndup_from_utf16(temp, max_len, 968 is_unicode, nls_codepage); 969 if (!node->path_name) { 970 rc = -ENOMEM; 971 goto parse_DFS_referrals_exit; 972 } 973 974 /* copy link target UNC */ 975 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset); 976 max_len = data_end - temp; 977 node->node_name = cifs_strndup_from_utf16(temp, max_len, 978 is_unicode, nls_codepage); 979 if (!node->node_name) { 980 rc = -ENOMEM; 981 goto parse_DFS_referrals_exit; 982 } 983 984 node->ttl = le32_to_cpu(ref->TimeToLive); 985 986 ref++; 987 } 988 989 parse_DFS_referrals_exit: 990 if (rc) { 991 free_dfs_info_array(*target_nodes, *num_of_nodes); 992 *target_nodes = NULL; 993 *num_of_nodes = 0; 994 } 995 return rc; 996 } 997 998 /** 999 * cifs_alloc_hash - allocate hash and hash context together 1000 * @name: The name of the crypto hash algo 1001 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM 1002 * 1003 * The caller has to make sure @sdesc is initialized to either NULL or 1004 * a valid context. It can be freed via cifs_free_hash(). 1005 */ 1006 int 1007 cifs_alloc_hash(const char *name, struct shash_desc **sdesc) 1008 { 1009 int rc = 0; 1010 struct crypto_shash *alg = NULL; 1011 1012 if (*sdesc) 1013 return 0; 1014 1015 alg = crypto_alloc_shash(name, 0, 0); 1016 if (IS_ERR(alg)) { 1017 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name); 1018 rc = PTR_ERR(alg); 1019 *sdesc = NULL; 1020 return rc; 1021 } 1022 1023 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL); 1024 if (*sdesc == NULL) { 1025 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name); 1026 crypto_free_shash(alg); 1027 return -ENOMEM; 1028 } 1029 1030 (*sdesc)->tfm = alg; 1031 return 0; 1032 } 1033 1034 /** 1035 * cifs_free_hash - free hash and hash context together 1036 * @sdesc: Where to find the pointer to the hash TFM 1037 * 1038 * Freeing a NULL descriptor is safe. 1039 */ 1040 void 1041 cifs_free_hash(struct shash_desc **sdesc) 1042 { 1043 if (unlikely(!sdesc) || !*sdesc) 1044 return; 1045 1046 if ((*sdesc)->tfm) { 1047 crypto_free_shash((*sdesc)->tfm); 1048 (*sdesc)->tfm = NULL; 1049 } 1050 1051 kfree_sensitive(*sdesc); 1052 *sdesc = NULL; 1053 } 1054 1055 void extract_unc_hostname(const char *unc, const char **h, size_t *len) 1056 { 1057 const char *end; 1058 1059 /* skip initial slashes */ 1060 while (*unc && (*unc == '\\' || *unc == '/')) 1061 unc++; 1062 1063 end = unc; 1064 1065 while (*end && !(*end == '\\' || *end == '/')) 1066 end++; 1067 1068 *h = unc; 1069 *len = end - unc; 1070 } 1071 1072 /** 1073 * copy_path_name - copy src path to dst, possibly truncating 1074 * @dst: The destination buffer 1075 * @src: The source name 1076 * 1077 * returns number of bytes written (including trailing nul) 1078 */ 1079 int copy_path_name(char *dst, const char *src) 1080 { 1081 int name_len; 1082 1083 /* 1084 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it 1085 * will truncate and strlen(dst) will be PATH_MAX-1 1086 */ 1087 name_len = strscpy(dst, src, PATH_MAX); 1088 if (WARN_ON_ONCE(name_len < 0)) 1089 name_len = PATH_MAX-1; 1090 1091 /* we count the trailing nul */ 1092 name_len++; 1093 return name_len; 1094 } 1095 1096 struct super_cb_data { 1097 void *data; 1098 struct super_block *sb; 1099 }; 1100 1101 static void tcon_super_cb(struct super_block *sb, void *arg) 1102 { 1103 struct super_cb_data *sd = arg; 1104 struct cifs_sb_info *cifs_sb; 1105 struct cifs_tcon *t1 = sd->data, *t2; 1106 1107 if (sd->sb) 1108 return; 1109 1110 cifs_sb = CIFS_SB(sb); 1111 t2 = cifs_sb_master_tcon(cifs_sb); 1112 1113 spin_lock(&t2->tc_lock); 1114 if ((t1->ses == t2->ses || 1115 t1->ses->dfs_root_ses == t2->ses->dfs_root_ses) && 1116 t1->ses->server == t2->ses->server && 1117 t2->origin_fullpath && 1118 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) 1119 sd->sb = sb; 1120 spin_unlock(&t2->tc_lock); 1121 } 1122 1123 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), 1124 void *data) 1125 { 1126 struct super_cb_data sd = { 1127 .data = data, 1128 .sb = NULL, 1129 }; 1130 struct file_system_type **fs_type = (struct file_system_type *[]) { 1131 &cifs_fs_type, &smb3_fs_type, NULL, 1132 }; 1133 1134 for (; *fs_type; fs_type++) { 1135 iterate_supers_type(*fs_type, f, &sd); 1136 if (sd.sb) { 1137 /* 1138 * Grab an active reference in order to prevent automounts (DFS links) 1139 * of expiring and then freeing up our cifs superblock pointer while 1140 * we're doing failover. 1141 */ 1142 cifs_sb_active(sd.sb); 1143 return sd.sb; 1144 } 1145 } 1146 pr_warn_once("%s: could not find dfs superblock\n", __func__); 1147 return ERR_PTR(-EINVAL); 1148 } 1149 1150 static void __cifs_put_super(struct super_block *sb) 1151 { 1152 if (!IS_ERR_OR_NULL(sb)) 1153 cifs_sb_deactive(sb); 1154 } 1155 1156 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) 1157 { 1158 spin_lock(&tcon->tc_lock); 1159 if (!tcon->origin_fullpath) { 1160 spin_unlock(&tcon->tc_lock); 1161 return ERR_PTR(-ENOENT); 1162 } 1163 spin_unlock(&tcon->tc_lock); 1164 return __cifs_get_super(tcon_super_cb, tcon); 1165 } 1166 1167 void cifs_put_tcp_super(struct super_block *sb) 1168 { 1169 __cifs_put_super(sb); 1170 } 1171 1172 #ifdef CONFIG_CIFS_DFS_UPCALL 1173 int match_target_ip(struct TCP_Server_Info *server, 1174 const char *share, size_t share_len, 1175 bool *result) 1176 { 1177 int rc; 1178 char *target; 1179 struct sockaddr_storage ss; 1180 1181 *result = false; 1182 1183 target = kzalloc(share_len + 3, GFP_KERNEL); 1184 if (!target) 1185 return -ENOMEM; 1186 1187 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share); 1188 1189 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2); 1190 1191 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL); 1192 kfree(target); 1193 1194 if (rc < 0) 1195 return rc; 1196 1197 spin_lock(&server->srv_lock); 1198 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss); 1199 spin_unlock(&server->srv_lock); 1200 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result); 1201 return 0; 1202 } 1203 1204 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 1205 { 1206 int rc; 1207 1208 kfree(cifs_sb->prepath); 1209 cifs_sb->prepath = NULL; 1210 1211 if (prefix && *prefix) { 1212 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); 1213 if (IS_ERR(cifs_sb->prepath)) { 1214 rc = PTR_ERR(cifs_sb->prepath); 1215 cifs_sb->prepath = NULL; 1216 return rc; 1217 } 1218 if (cifs_sb->prepath) 1219 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); 1220 } 1221 1222 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; 1223 return 0; 1224 } 1225 1226 /* 1227 * Handle weird Windows SMB server behaviour. It responds with 1228 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for 1229 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains 1230 * non-ASCII unicode symbols. 1231 */ 1232 int cifs_inval_name_dfs_link_error(const unsigned int xid, 1233 struct cifs_tcon *tcon, 1234 struct cifs_sb_info *cifs_sb, 1235 const char *full_path, 1236 bool *islink) 1237 { 1238 struct TCP_Server_Info *server = tcon->ses->server; 1239 struct cifs_ses *ses = tcon->ses; 1240 size_t len; 1241 char *path; 1242 char *ref_path; 1243 1244 *islink = false; 1245 1246 /* 1247 * Fast path - skip check when @full_path doesn't have a prefix path to 1248 * look up or tcon is not DFS. 1249 */ 1250 if (strlen(full_path) < 2 || !cifs_sb || 1251 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || 1252 !is_tcon_dfs(tcon)) 1253 return 0; 1254 1255 spin_lock(&server->srv_lock); 1256 if (!server->leaf_fullpath) { 1257 spin_unlock(&server->srv_lock); 1258 return 0; 1259 } 1260 spin_unlock(&server->srv_lock); 1261 1262 /* 1263 * Slow path - tcon is DFS and @full_path has prefix path, so attempt 1264 * to get a referral to figure out whether it is an DFS link. 1265 */ 1266 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; 1267 path = kmalloc(len, GFP_KERNEL); 1268 if (!path) 1269 return -ENOMEM; 1270 1271 scnprintf(path, len, "%s%s", tcon->tree_name, full_path); 1272 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, 1273 cifs_remap(cifs_sb)); 1274 kfree(path); 1275 1276 if (IS_ERR(ref_path)) { 1277 if (PTR_ERR(ref_path) != -EINVAL) 1278 return PTR_ERR(ref_path); 1279 } else { 1280 struct dfs_info3_param *refs = NULL; 1281 int num_refs = 0; 1282 1283 /* 1284 * XXX: we are not using dfs_cache_find() here because we might 1285 * end up filling all the DFS cache and thus potentially 1286 * removing cached DFS targets that the client would eventually 1287 * need during failover. 1288 */ 1289 ses = CIFS_DFS_ROOT_SES(ses); 1290 if (ses->server->ops->get_dfs_refer && 1291 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, 1292 &num_refs, cifs_sb->local_nls, 1293 cifs_remap(cifs_sb))) 1294 *islink = refs[0].server_type == DFS_TYPE_LINK; 1295 free_dfs_info_array(refs, num_refs); 1296 kfree(ref_path); 1297 } 1298 return 0; 1299 } 1300 #endif 1301 1302 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) 1303 { 1304 int timeout = 10; 1305 int rc; 1306 1307 spin_lock(&server->srv_lock); 1308 if (server->tcpStatus != CifsNeedReconnect) { 1309 spin_unlock(&server->srv_lock); 1310 return 0; 1311 } 1312 timeout *= server->nr_targets; 1313 spin_unlock(&server->srv_lock); 1314 1315 /* 1316 * Give demultiplex thread up to 10 seconds to each target available for 1317 * reconnect -- should be greater than cifs socket timeout which is 7 1318 * seconds. 1319 * 1320 * On "soft" mounts we wait once. Hard mounts keep retrying until 1321 * process is killed or server comes back on-line. 1322 */ 1323 do { 1324 rc = wait_event_interruptible_timeout(server->response_q, 1325 (server->tcpStatus != CifsNeedReconnect), 1326 timeout * HZ); 1327 if (rc < 0) { 1328 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", 1329 __func__); 1330 return -ERESTARTSYS; 1331 } 1332 1333 /* are we still trying to reconnect? */ 1334 spin_lock(&server->srv_lock); 1335 if (server->tcpStatus != CifsNeedReconnect) { 1336 spin_unlock(&server->srv_lock); 1337 return 0; 1338 } 1339 spin_unlock(&server->srv_lock); 1340 } while (retry); 1341 1342 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); 1343 return -EHOSTDOWN; 1344 } 1345