at v3.16 911 lines 24 kB view raw
1/* 2 * fs/cifs/dir.c 3 * 4 * vfs operations that deal with dentries 5 * 6 * Copyright (C) International Business Machines Corp., 2002,2009 7 * Author(s): Steve French (sfrench@us.ibm.com) 8 * 9 * This library is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU Lesser General Public License as published 11 * by the Free Software Foundation; either version 2.1 of the License, or 12 * (at your option) any later version. 13 * 14 * This library is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 17 * the GNU Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public License 20 * along with this library; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23#include <linux/fs.h> 24#include <linux/stat.h> 25#include <linux/slab.h> 26#include <linux/namei.h> 27#include <linux/mount.h> 28#include <linux/file.h> 29#include "cifsfs.h" 30#include "cifspdu.h" 31#include "cifsglob.h" 32#include "cifsproto.h" 33#include "cifs_debug.h" 34#include "cifs_fs_sb.h" 35#include "cifs_unicode.h" 36 37static void 38renew_parental_timestamps(struct dentry *direntry) 39{ 40 /* BB check if there is a way to get the kernel to do this or if we 41 really need this */ 42 do { 43 direntry->d_time = jiffies; 44 direntry = direntry->d_parent; 45 } while (!IS_ROOT(direntry)); 46} 47 48char * 49cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, 50 struct cifs_tcon *tcon) 51{ 52 int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0; 53 int dfsplen; 54 char *full_path = NULL; 55 56 /* if no prefix path, simply set path to the root of share to "" */ 57 if (pplen == 0) { 58 full_path = kzalloc(1, GFP_KERNEL); 59 return full_path; 60 } 61 62 if (tcon->Flags & SMB_SHARE_IS_IN_DFS) 63 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); 64 else 65 dfsplen = 0; 66 67 full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL); 68 if (full_path == NULL) 69 return full_path; 70 71 if (dfsplen) 72 strncpy(full_path, tcon->treeName, dfsplen); 73 full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb); 74 strncpy(full_path + dfsplen + 1, vol->prepath, pplen); 75 convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb)); 76 full_path[dfsplen + pplen] = 0; /* add trailing null */ 77 return full_path; 78} 79 80/* Note: caller must free return buffer */ 81char * 82build_path_from_dentry(struct dentry *direntry) 83{ 84 struct dentry *temp; 85 int namelen; 86 int dfsplen; 87 char *full_path; 88 char dirsep; 89 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); 90 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); 91 unsigned seq; 92 93 dirsep = CIFS_DIR_SEP(cifs_sb); 94 if (tcon->Flags & SMB_SHARE_IS_IN_DFS) 95 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); 96 else 97 dfsplen = 0; 98cifs_bp_rename_retry: 99 namelen = dfsplen; 100 seq = read_seqbegin(&rename_lock); 101 rcu_read_lock(); 102 for (temp = direntry; !IS_ROOT(temp);) { 103 namelen += (1 + temp->d_name.len); 104 temp = temp->d_parent; 105 if (temp == NULL) { 106 cifs_dbg(VFS, "corrupt dentry\n"); 107 rcu_read_unlock(); 108 return NULL; 109 } 110 } 111 rcu_read_unlock(); 112 113 full_path = kmalloc(namelen+1, GFP_KERNEL); 114 if (full_path == NULL) 115 return full_path; 116 full_path[namelen] = 0; /* trailing null */ 117 rcu_read_lock(); 118 for (temp = direntry; !IS_ROOT(temp);) { 119 spin_lock(&temp->d_lock); 120 namelen -= 1 + temp->d_name.len; 121 if (namelen < 0) { 122 spin_unlock(&temp->d_lock); 123 break; 124 } else { 125 full_path[namelen] = dirsep; 126 strncpy(full_path + namelen + 1, temp->d_name.name, 127 temp->d_name.len); 128 cifs_dbg(FYI, "name: %s\n", full_path + namelen); 129 } 130 spin_unlock(&temp->d_lock); 131 temp = temp->d_parent; 132 if (temp == NULL) { 133 cifs_dbg(VFS, "corrupt dentry\n"); 134 rcu_read_unlock(); 135 kfree(full_path); 136 return NULL; 137 } 138 } 139 rcu_read_unlock(); 140 if (namelen != dfsplen || read_seqretry(&rename_lock, seq)) { 141 cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n", 142 namelen, dfsplen); 143 /* presumably this is only possible if racing with a rename 144 of one of the parent directories (we can not lock the dentries 145 above us to prevent this, but retrying should be harmless) */ 146 kfree(full_path); 147 goto cifs_bp_rename_retry; 148 } 149 /* DIR_SEP already set for byte 0 / vs \ but not for 150 subsequent slashes in prepath which currently must 151 be entered the right way - not sure if there is an alternative 152 since the '\' is a valid posix character so we can not switch 153 those safely to '/' if any are found in the middle of the prepath */ 154 /* BB test paths to Windows with '/' in the midst of prepath */ 155 156 if (dfsplen) { 157 strncpy(full_path, tcon->treeName, dfsplen); 158 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) { 159 int i; 160 for (i = 0; i < dfsplen; i++) { 161 if (full_path[i] == '\\') 162 full_path[i] = '/'; 163 } 164 } 165 } 166 return full_path; 167} 168 169/* 170 * Don't allow the separator character in a path component. 171 * The VFS will not allow "/", but "\" is allowed by posix. 172 */ 173static int 174check_name(struct dentry *direntry) 175{ 176 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); 177 int i; 178 179 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) { 180 for (i = 0; i < direntry->d_name.len; i++) { 181 if (direntry->d_name.name[i] == '\\') { 182 cifs_dbg(FYI, "Invalid file name\n"); 183 return -EINVAL; 184 } 185 } 186 } 187 return 0; 188} 189 190 191/* Inode operations in similar order to how they appear in Linux file fs.h */ 192 193static int 194cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, 195 struct tcon_link *tlink, unsigned oflags, umode_t mode, 196 __u32 *oplock, struct cifs_fid *fid) 197{ 198 int rc = -ENOENT; 199 int create_options = CREATE_NOT_DIR; 200 int desired_access; 201 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); 202 struct cifs_tcon *tcon = tlink_tcon(tlink); 203 char *full_path = NULL; 204 FILE_ALL_INFO *buf = NULL; 205 struct inode *newinode = NULL; 206 int disposition; 207 struct TCP_Server_Info *server = tcon->ses->server; 208 struct cifs_open_parms oparms; 209 210 *oplock = 0; 211 if (tcon->ses->server->oplocks) 212 *oplock = REQ_OPLOCK; 213 214 full_path = build_path_from_dentry(direntry); 215 if (full_path == NULL) { 216 rc = -ENOMEM; 217 goto out; 218 } 219 220 if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open && 221 (CIFS_UNIX_POSIX_PATH_OPS_CAP & 222 le64_to_cpu(tcon->fsUnixInfo.Capability))) { 223 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode, 224 oflags, oplock, &fid->netfid, xid); 225 switch (rc) { 226 case 0: 227 if (newinode == NULL) { 228 /* query inode info */ 229 goto cifs_create_get_file_info; 230 } 231 232 if (!S_ISREG(newinode->i_mode)) { 233 /* 234 * The server may allow us to open things like 235 * FIFOs, but the client isn't set up to deal 236 * with that. If it's not a regular file, just 237 * close it and proceed as if it were a normal 238 * lookup. 239 */ 240 CIFSSMBClose(xid, tcon, fid->netfid); 241 goto cifs_create_get_file_info; 242 } 243 /* success, no need to query */ 244 goto cifs_create_set_dentry; 245 246 case -ENOENT: 247 goto cifs_create_get_file_info; 248 249 case -EIO: 250 case -EINVAL: 251 /* 252 * EIO could indicate that (posix open) operation is not 253 * supported, despite what server claimed in capability 254 * negotiation. 255 * 256 * POSIX open in samba versions 3.3.1 and earlier could 257 * incorrectly fail with invalid parameter. 258 */ 259 tcon->broken_posix_open = true; 260 break; 261 262 case -EREMOTE: 263 case -EOPNOTSUPP: 264 /* 265 * EREMOTE indicates DFS junction, which is not handled 266 * in posix open. If either that or op not supported 267 * returned, follow the normal lookup. 268 */ 269 break; 270 271 default: 272 goto out; 273 } 274 /* 275 * fallthrough to retry, using older open call, this is case 276 * where server does not support this SMB level, and falsely 277 * claims capability (also get here for DFS case which should be 278 * rare for path not covered on files) 279 */ 280 } 281 282 desired_access = 0; 283 if (OPEN_FMODE(oflags) & FMODE_READ) 284 desired_access |= GENERIC_READ; /* is this too little? */ 285 if (OPEN_FMODE(oflags) & FMODE_WRITE) 286 desired_access |= GENERIC_WRITE; 287 288 disposition = FILE_OVERWRITE_IF; 289 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) 290 disposition = FILE_CREATE; 291 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC)) 292 disposition = FILE_OVERWRITE_IF; 293 else if ((oflags & O_CREAT) == O_CREAT) 294 disposition = FILE_OPEN_IF; 295 else 296 cifs_dbg(FYI, "Create flag not set in create function\n"); 297 298 /* 299 * BB add processing to set equivalent of mode - e.g. via CreateX with 300 * ACLs 301 */ 302 303 if (!server->ops->open) { 304 rc = -ENOSYS; 305 goto out; 306 } 307 308 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL); 309 if (buf == NULL) { 310 rc = -ENOMEM; 311 goto out; 312 } 313 314 /* 315 * if we're not using unix extensions, see if we need to set 316 * ATTR_READONLY on the create call 317 */ 318 if (!tcon->unix_ext && (mode & S_IWUGO) == 0) 319 create_options |= CREATE_OPTION_READONLY; 320 321 if (backup_cred(cifs_sb)) 322 create_options |= CREATE_OPEN_BACKUP_INTENT; 323 324 oparms.tcon = tcon; 325 oparms.cifs_sb = cifs_sb; 326 oparms.desired_access = desired_access; 327 oparms.create_options = create_options; 328 oparms.disposition = disposition; 329 oparms.path = full_path; 330 oparms.fid = fid; 331 oparms.reconnect = false; 332 333 rc = server->ops->open(xid, &oparms, oplock, buf); 334 if (rc) { 335 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc); 336 goto out; 337 } 338 339 /* 340 * If Open reported that we actually created a file then we now have to 341 * set the mode if possible. 342 */ 343 if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) { 344 struct cifs_unix_set_info_args args = { 345 .mode = mode, 346 .ctime = NO_CHANGE_64, 347 .atime = NO_CHANGE_64, 348 .mtime = NO_CHANGE_64, 349 .device = 0, 350 }; 351 352 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) { 353 args.uid = current_fsuid(); 354 if (inode->i_mode & S_ISGID) 355 args.gid = inode->i_gid; 356 else 357 args.gid = current_fsgid(); 358 } else { 359 args.uid = INVALID_UID; /* no change */ 360 args.gid = INVALID_GID; /* no change */ 361 } 362 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid, 363 current->tgid); 364 } else { 365 /* 366 * BB implement mode setting via Windows security 367 * descriptors e.g. 368 */ 369 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/ 370 371 /* Could set r/o dos attribute if mode & 0222 == 0 */ 372 } 373 374cifs_create_get_file_info: 375 /* server might mask mode so we have to query for it */ 376 if (tcon->unix_ext) 377 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb, 378 xid); 379 else { 380 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, 381 xid, fid); 382 if (newinode) { 383 if (server->ops->set_lease_key) 384 server->ops->set_lease_key(newinode, fid); 385 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) 386 newinode->i_mode = mode; 387 if ((*oplock & CIFS_CREATE_ACTION) && 388 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) { 389 newinode->i_uid = current_fsuid(); 390 if (inode->i_mode & S_ISGID) 391 newinode->i_gid = inode->i_gid; 392 else 393 newinode->i_gid = current_fsgid(); 394 } 395 } 396 } 397 398cifs_create_set_dentry: 399 if (rc != 0) { 400 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n", 401 rc); 402 if (server->ops->close) 403 server->ops->close(xid, tcon, fid); 404 goto out; 405 } 406 d_drop(direntry); 407 d_add(direntry, newinode); 408 409out: 410 kfree(buf); 411 kfree(full_path); 412 return rc; 413} 414 415int 416cifs_atomic_open(struct inode *inode, struct dentry *direntry, 417 struct file *file, unsigned oflags, umode_t mode, 418 int *opened) 419{ 420 int rc; 421 unsigned int xid; 422 struct tcon_link *tlink; 423 struct cifs_tcon *tcon; 424 struct TCP_Server_Info *server; 425 struct cifs_fid fid; 426 struct cifs_pending_open open; 427 __u32 oplock; 428 struct cifsFileInfo *file_info; 429 430 /* 431 * Posix open is only called (at lookup time) for file create now. For 432 * opens (rather than creates), because we do not know if it is a file 433 * or directory yet, and current Samba no longer allows us to do posix 434 * open on dirs, we could end up wasting an open call on what turns out 435 * to be a dir. For file opens, we wait to call posix open till 436 * cifs_open. It could be added to atomic_open in the future but the 437 * performance tradeoff of the extra network request when EISDIR or 438 * EACCES is returned would have to be weighed against the 50% reduction 439 * in network traffic in the other paths. 440 */ 441 if (!(oflags & O_CREAT)) { 442 struct dentry *res; 443 444 /* 445 * Check for hashed negative dentry. We have already revalidated 446 * the dentry and it is fine. No need to perform another lookup. 447 */ 448 if (!d_unhashed(direntry)) 449 return -ENOENT; 450 451 res = cifs_lookup(inode, direntry, 0); 452 if (IS_ERR(res)) 453 return PTR_ERR(res); 454 455 return finish_no_open(file, res); 456 } 457 458 rc = check_name(direntry); 459 if (rc) 460 return rc; 461 462 xid = get_xid(); 463 464 cifs_dbg(FYI, "parent inode = 0x%p name is: %s and dentry = 0x%p\n", 465 inode, direntry->d_name.name, direntry); 466 467 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb)); 468 if (IS_ERR(tlink)) { 469 rc = PTR_ERR(tlink); 470 goto out_free_xid; 471 } 472 473 tcon = tlink_tcon(tlink); 474 server = tcon->ses->server; 475 476 if (server->ops->new_lease_key) 477 server->ops->new_lease_key(&fid); 478 479 cifs_add_pending_open(&fid, tlink, &open); 480 481 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, 482 &oplock, &fid); 483 484 if (rc) { 485 cifs_del_pending_open(&open); 486 goto out; 487 } 488 489 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) 490 *opened |= FILE_CREATED; 491 492 rc = finish_open(file, direntry, generic_file_open, opened); 493 if (rc) { 494 if (server->ops->close) 495 server->ops->close(xid, tcon, &fid); 496 cifs_del_pending_open(&open); 497 goto out; 498 } 499 500 file_info = cifs_new_fileinfo(&fid, file, tlink, oplock); 501 if (file_info == NULL) { 502 if (server->ops->close) 503 server->ops->close(xid, tcon, &fid); 504 cifs_del_pending_open(&open); 505 fput(file); 506 rc = -ENOMEM; 507 } 508 509out: 510 cifs_put_tlink(tlink); 511out_free_xid: 512 free_xid(xid); 513 return rc; 514} 515 516int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode, 517 bool excl) 518{ 519 int rc; 520 unsigned int xid = get_xid(); 521 /* 522 * BB below access is probably too much for mknod to request 523 * but we have to do query and setpathinfo so requesting 524 * less could fail (unless we want to request getatr and setatr 525 * permissions (only). At least for POSIX we do not have to 526 * request so much. 527 */ 528 unsigned oflags = O_EXCL | O_CREAT | O_RDWR; 529 struct tcon_link *tlink; 530 struct cifs_tcon *tcon; 531 struct TCP_Server_Info *server; 532 struct cifs_fid fid; 533 __u32 oplock; 534 535 cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %s and dentry = 0x%p\n", 536 inode, direntry->d_name.name, direntry); 537 538 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb)); 539 rc = PTR_ERR(tlink); 540 if (IS_ERR(tlink)) 541 goto out_free_xid; 542 543 tcon = tlink_tcon(tlink); 544 server = tcon->ses->server; 545 546 if (server->ops->new_lease_key) 547 server->ops->new_lease_key(&fid); 548 549 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, 550 &oplock, &fid); 551 if (!rc && server->ops->close) 552 server->ops->close(xid, tcon, &fid); 553 554 cifs_put_tlink(tlink); 555out_free_xid: 556 free_xid(xid); 557 return rc; 558} 559 560int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode, 561 dev_t device_number) 562{ 563 int rc = -EPERM; 564 unsigned int xid; 565 int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL; 566 struct cifs_sb_info *cifs_sb; 567 struct tcon_link *tlink; 568 struct cifs_tcon *tcon; 569 struct cifs_io_parms io_parms; 570 char *full_path = NULL; 571 struct inode *newinode = NULL; 572 int oplock = 0; 573 struct cifs_fid fid; 574 struct cifs_open_parms oparms; 575 FILE_ALL_INFO *buf = NULL; 576 unsigned int bytes_written; 577 struct win_dev *pdev; 578 579 if (!old_valid_dev(device_number)) 580 return -EINVAL; 581 582 cifs_sb = CIFS_SB(inode->i_sb); 583 tlink = cifs_sb_tlink(cifs_sb); 584 if (IS_ERR(tlink)) 585 return PTR_ERR(tlink); 586 587 tcon = tlink_tcon(tlink); 588 589 xid = get_xid(); 590 591 full_path = build_path_from_dentry(direntry); 592 if (full_path == NULL) { 593 rc = -ENOMEM; 594 goto mknod_out; 595 } 596 597 if (tcon->unix_ext) { 598 struct cifs_unix_set_info_args args = { 599 .mode = mode & ~current_umask(), 600 .ctime = NO_CHANGE_64, 601 .atime = NO_CHANGE_64, 602 .mtime = NO_CHANGE_64, 603 .device = device_number, 604 }; 605 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) { 606 args.uid = current_fsuid(); 607 args.gid = current_fsgid(); 608 } else { 609 args.uid = INVALID_UID; /* no change */ 610 args.gid = INVALID_GID; /* no change */ 611 } 612 rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args, 613 cifs_sb->local_nls, 614 cifs_sb->mnt_cifs_flags & 615 CIFS_MOUNT_MAP_SPECIAL_CHR); 616 if (rc) 617 goto mknod_out; 618 619 rc = cifs_get_inode_info_unix(&newinode, full_path, 620 inode->i_sb, xid); 621 622 if (rc == 0) 623 d_instantiate(direntry, newinode); 624 goto mknod_out; 625 } 626 627 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)) 628 goto mknod_out; 629 630 631 cifs_dbg(FYI, "sfu compat create special file\n"); 632 633 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL); 634 if (buf == NULL) { 635 kfree(full_path); 636 rc = -ENOMEM; 637 free_xid(xid); 638 return rc; 639 } 640 641 if (backup_cred(cifs_sb)) 642 create_options |= CREATE_OPEN_BACKUP_INTENT; 643 644 oparms.tcon = tcon; 645 oparms.cifs_sb = cifs_sb; 646 oparms.desired_access = GENERIC_WRITE; 647 oparms.create_options = create_options; 648 oparms.disposition = FILE_CREATE; 649 oparms.path = full_path; 650 oparms.fid = &fid; 651 oparms.reconnect = false; 652 653 rc = CIFS_open(xid, &oparms, &oplock, buf); 654 if (rc) 655 goto mknod_out; 656 657 /* 658 * BB Do not bother to decode buf since no local inode yet to put 659 * timestamps in, but we can reuse it safely. 660 */ 661 662 pdev = (struct win_dev *)buf; 663 io_parms.netfid = fid.netfid; 664 io_parms.pid = current->tgid; 665 io_parms.tcon = tcon; 666 io_parms.offset = 0; 667 io_parms.length = sizeof(struct win_dev); 668 if (S_ISCHR(mode)) { 669 memcpy(pdev->type, "IntxCHR", 8); 670 pdev->major = cpu_to_le64(MAJOR(device_number)); 671 pdev->minor = cpu_to_le64(MINOR(device_number)); 672 rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, (char *)pdev, 673 NULL, 0); 674 } else if (S_ISBLK(mode)) { 675 memcpy(pdev->type, "IntxBLK", 8); 676 pdev->major = cpu_to_le64(MAJOR(device_number)); 677 pdev->minor = cpu_to_le64(MINOR(device_number)); 678 rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, (char *)pdev, 679 NULL, 0); 680 } /* else if (S_ISFIFO) */ 681 CIFSSMBClose(xid, tcon, fid.netfid); 682 d_drop(direntry); 683 684 /* FIXME: add code here to set EAs */ 685 686mknod_out: 687 kfree(full_path); 688 kfree(buf); 689 free_xid(xid); 690 cifs_put_tlink(tlink); 691 return rc; 692} 693 694struct dentry * 695cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, 696 unsigned int flags) 697{ 698 unsigned int xid; 699 int rc = 0; /* to get around spurious gcc warning, set to zero here */ 700 struct cifs_sb_info *cifs_sb; 701 struct tcon_link *tlink; 702 struct cifs_tcon *pTcon; 703 struct inode *newInode = NULL; 704 char *full_path = NULL; 705 706 xid = get_xid(); 707 708 cifs_dbg(FYI, "parent inode = 0x%p name is: %s and dentry = 0x%p\n", 709 parent_dir_inode, direntry->d_name.name, direntry); 710 711 /* check whether path exists */ 712 713 cifs_sb = CIFS_SB(parent_dir_inode->i_sb); 714 tlink = cifs_sb_tlink(cifs_sb); 715 if (IS_ERR(tlink)) { 716 free_xid(xid); 717 return (struct dentry *)tlink; 718 } 719 pTcon = tlink_tcon(tlink); 720 721 rc = check_name(direntry); 722 if (rc) 723 goto lookup_out; 724 725 /* can not grab the rename sem here since it would 726 deadlock in the cases (beginning of sys_rename itself) 727 in which we already have the sb rename sem */ 728 full_path = build_path_from_dentry(direntry); 729 if (full_path == NULL) { 730 rc = -ENOMEM; 731 goto lookup_out; 732 } 733 734 if (direntry->d_inode != NULL) { 735 cifs_dbg(FYI, "non-NULL inode in lookup\n"); 736 } else { 737 cifs_dbg(FYI, "NULL inode in lookup\n"); 738 } 739 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", 740 full_path, direntry->d_inode); 741 742 if (pTcon->unix_ext) { 743 rc = cifs_get_inode_info_unix(&newInode, full_path, 744 parent_dir_inode->i_sb, xid); 745 } else { 746 rc = cifs_get_inode_info(&newInode, full_path, NULL, 747 parent_dir_inode->i_sb, xid, NULL); 748 } 749 750 if ((rc == 0) && (newInode != NULL)) { 751 d_add(direntry, newInode); 752 /* since paths are not looked up by component - the parent 753 directories are presumed to be good here */ 754 renew_parental_timestamps(direntry); 755 756 } else if (rc == -ENOENT) { 757 rc = 0; 758 direntry->d_time = jiffies; 759 d_add(direntry, NULL); 760 /* if it was once a directory (but how can we tell?) we could do 761 shrink_dcache_parent(direntry); */ 762 } else if (rc != -EACCES) { 763 cifs_dbg(FYI, "Unexpected lookup error %d\n", rc); 764 /* We special case check for Access Denied - since that 765 is a common return code */ 766 } 767 768lookup_out: 769 kfree(full_path); 770 cifs_put_tlink(tlink); 771 free_xid(xid); 772 return ERR_PTR(rc); 773} 774 775static int 776cifs_d_revalidate(struct dentry *direntry, unsigned int flags) 777{ 778 if (flags & LOOKUP_RCU) 779 return -ECHILD; 780 781 if (direntry->d_inode) { 782 if (cifs_revalidate_dentry(direntry)) 783 return 0; 784 else { 785 /* 786 * If the inode wasn't known to be a dfs entry when 787 * the dentry was instantiated, such as when created 788 * via ->readdir(), it needs to be set now since the 789 * attributes will have been updated by 790 * cifs_revalidate_dentry(). 791 */ 792 if (IS_AUTOMOUNT(direntry->d_inode) && 793 !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) { 794 spin_lock(&direntry->d_lock); 795 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT; 796 spin_unlock(&direntry->d_lock); 797 } 798 799 return 1; 800 } 801 } 802 803 /* 804 * This may be nfsd (or something), anyway, we can't see the 805 * intent of this. So, since this can be for creation, drop it. 806 */ 807 if (!flags) 808 return 0; 809 810 /* 811 * Drop the negative dentry, in order to make sure to use the 812 * case sensitive name which is specified by user if this is 813 * for creation. 814 */ 815 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) 816 return 0; 817 818 if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled) 819 return 0; 820 821 return 1; 822} 823 824/* static int cifs_d_delete(struct dentry *direntry) 825{ 826 int rc = 0; 827 828 cifs_dbg(FYI, "In cifs d_delete, name = %s\n", direntry->d_name.name); 829 830 return rc; 831} */ 832 833const struct dentry_operations cifs_dentry_ops = { 834 .d_revalidate = cifs_d_revalidate, 835 .d_automount = cifs_dfs_d_automount, 836/* d_delete: cifs_d_delete, */ /* not needed except for debugging */ 837}; 838 839static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q) 840{ 841 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls; 842 unsigned long hash; 843 wchar_t c; 844 int i, charlen; 845 846 hash = init_name_hash(); 847 for (i = 0; i < q->len; i += charlen) { 848 charlen = codepage->char2uni(&q->name[i], q->len - i, &c); 849 /* error out if we can't convert the character */ 850 if (unlikely(charlen < 0)) 851 return charlen; 852 hash = partial_name_hash(cifs_toupper(c), hash); 853 } 854 q->hash = end_name_hash(hash); 855 856 return 0; 857} 858 859static int cifs_ci_compare(const struct dentry *parent, const struct dentry *dentry, 860 unsigned int len, const char *str, const struct qstr *name) 861{ 862 struct nls_table *codepage = CIFS_SB(parent->d_sb)->local_nls; 863 wchar_t c1, c2; 864 int i, l1, l2; 865 866 /* 867 * We make the assumption here that uppercase characters in the local 868 * codepage are always the same length as their lowercase counterparts. 869 * 870 * If that's ever not the case, then this will fail to match it. 871 */ 872 if (name->len != len) 873 return 1; 874 875 for (i = 0; i < len; i += l1) { 876 /* Convert characters in both strings to UTF-16. */ 877 l1 = codepage->char2uni(&str[i], len - i, &c1); 878 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2); 879 880 /* 881 * If we can't convert either character, just declare it to 882 * be 1 byte long and compare the original byte. 883 */ 884 if (unlikely(l1 < 0 && l2 < 0)) { 885 if (str[i] != name->name[i]) 886 return 1; 887 l1 = 1; 888 continue; 889 } 890 891 /* 892 * Here, we again ass|u|me that upper/lowercase versions of 893 * a character are the same length in the local NLS. 894 */ 895 if (l1 != l2) 896 return 1; 897 898 /* Now compare uppercase versions of these characters */ 899 if (cifs_toupper(c1) != cifs_toupper(c2)) 900 return 1; 901 } 902 903 return 0; 904} 905 906const struct dentry_operations cifs_ci_dentry_ops = { 907 .d_revalidate = cifs_d_revalidate, 908 .d_hash = cifs_ci_hash, 909 .d_compare = cifs_ci_compare, 910 .d_automount = cifs_dfs_d_automount, 911};