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