1// SPDX-License-Identifier: LGPL-2.1 2/* 3 * 4 * Directory search handling 5 * 6 * Copyright (C) International Business Machines Corp., 2004, 2008 7 * Copyright (C) Red Hat, Inc., 2011 8 * Author(s): Steve French (sfrench@us.ibm.com) 9 * 10 */ 11#include <linux/fs.h> 12#include <linux/pagemap.h> 13#include <linux/slab.h> 14#include <linux/stat.h> 15#include "cifspdu.h" 16#include "cifsglob.h" 17#include "cifsproto.h" 18#include "cifs_unicode.h" 19#include "cifs_debug.h" 20#include "cifs_fs_sb.h" 21#include "cifsfs.h" 22#include "smb2proto.h" 23#include "fs_context.h" 24#include "cached_dir.h" 25 26/* 27 * To be safe - for UCS to UTF-8 with strings loaded with the rare long 28 * characters alloc more to account for such multibyte target UTF-8 29 * characters. 30 */ 31#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2) 32 33#ifdef CONFIG_CIFS_DEBUG2 34static void dump_cifs_file_struct(struct file *file, char *label) 35{ 36 struct cifsFileInfo *cf; 37 38 if (file) { 39 cf = file->private_data; 40 if (cf == NULL) { 41 cifs_dbg(FYI, "empty cifs private file data\n"); 42 return; 43 } 44 if (cf->invalidHandle) 45 cifs_dbg(FYI, "Invalid handle\n"); 46 if (cf->srch_inf.endOfSearch) 47 cifs_dbg(FYI, "end of search\n"); 48 if (cf->srch_inf.emptyDir) 49 cifs_dbg(FYI, "empty dir\n"); 50 } 51} 52#else 53static inline void dump_cifs_file_struct(struct file *file, char *label) 54{ 55} 56#endif /* DEBUG2 */ 57 58/* 59 * Match a reparse point inode if reparse tag and ctime haven't changed. 60 * 61 * Windows Server updates ctime of reparse points when their data have changed. 62 * The server doesn't allow changing reparse tags from existing reparse points, 63 * though it's worth checking. 64 */ 65static inline bool reparse_inode_match(struct inode *inode, 66 struct cifs_fattr *fattr) 67{ 68 struct timespec64 ctime = inode_get_ctime(inode); 69 70 return (CIFS_I(inode)->cifsAttrs & ATTR_REPARSE) && 71 CIFS_I(inode)->reparse_tag == fattr->cf_cifstag && 72 timespec64_equal(&ctime, &fattr->cf_ctime); 73} 74 75/* 76 * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT 77 * 78 * Find the dentry that matches "name". If there isn't one, create one. If it's 79 * a negative dentry or the uniqueid or filetype(mode) changed, 80 * then drop it and recreate it. 81 */ 82static void 83cifs_prime_dcache(struct dentry *parent, struct qstr *name, 84 struct cifs_fattr *fattr) 85{ 86 struct dentry *dentry, *alias; 87 struct inode *inode; 88 struct super_block *sb = parent->d_sb; 89 struct cifs_sb_info *cifs_sb = CIFS_SB(sb); 90 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 91 int rc; 92 93 cifs_dbg(FYI, "%s: for %s\n", __func__, name->name); 94 95 dentry = d_hash_and_lookup(parent, name); 96 if (!dentry) { 97 /* 98 * If we know that the inode will need to be revalidated 99 * immediately, then don't create a new dentry for it. 100 * We'll end up doing an on the wire call either way and 101 * this spares us an invalidation. 102 */ 103retry: 104 if ((fattr->cf_cifsattrs & ATTR_REPARSE) || 105 (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)) 106 return; 107 108 dentry = d_alloc_parallel(parent, name, &wq); 109 } 110 if (IS_ERR(dentry)) 111 return; 112 if (!d_in_lookup(dentry)) { 113 inode = d_inode(dentry); 114 if (inode) { 115 if (d_mountpoint(dentry)) { 116 dput(dentry); 117 return; 118 } 119 /* 120 * If we're generating inode numbers, then we don't 121 * want to clobber the existing one with the one that 122 * the readdir code created. 123 */ 124 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) 125 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid; 126 127 /* 128 * Update inode in place if both i_ino and i_mode didn't 129 * change. 130 */ 131 if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) { 132 /* 133 * Query dir responses don't provide enough 134 * information about reparse points other than 135 * their reparse tags. Save an invalidation by 136 * not clobbering the existing mode, size and 137 * symlink target (if any) when reparse tag and 138 * ctime haven't changed. 139 */ 140 rc = 0; 141 if (fattr->cf_cifsattrs & ATTR_REPARSE) { 142 if (likely(reparse_inode_match(inode, fattr))) { 143 fattr->cf_mode = inode->i_mode; 144 fattr->cf_eof = CIFS_I(inode)->server_eof; 145 fattr->cf_symlink_target = NULL; 146 } else { 147 CIFS_I(inode)->time = 0; 148 rc = -ESTALE; 149 } 150 } 151 if (!rc && !cifs_fattr_to_inode(inode, fattr, true)) { 152 dput(dentry); 153 return; 154 } 155 } 156 } 157 d_invalidate(dentry); 158 dput(dentry); 159 goto retry; 160 } else { 161 inode = cifs_iget(sb, fattr); 162 if (!inode) 163 inode = ERR_PTR(-ENOMEM); 164 alias = d_splice_alias(inode, dentry); 165 d_lookup_done(dentry); 166 if (alias && !IS_ERR(alias)) 167 dput(alias); 168 } 169 dput(dentry); 170} 171 172static void 173cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb) 174{ 175 struct cifs_open_info_data data = { 176 .reparse = { .tag = fattr->cf_cifstag, }, 177 }; 178 179 fattr->cf_uid = cifs_sb->ctx->linux_uid; 180 fattr->cf_gid = cifs_sb->ctx->linux_gid; 181 182 /* 183 * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they 184 * are preferred by the Linux client in some cases since, unlike 185 * the NFS reparse tag (or EAs), they don't require an extra query 186 * to determine which type of special file they represent. 187 * TODO: go through all documented reparse tags to see if we can 188 * reasonably map some of them to directories vs. files vs. symlinks 189 */ 190 if ((fattr->cf_cifsattrs & ATTR_REPARSE) && 191 cifs_reparse_point_to_fattr(cifs_sb, fattr, &data)) 192 goto out_reparse; 193 194 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) { 195 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode; 196 fattr->cf_dtype = DT_DIR; 197 } else { 198 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode; 199 fattr->cf_dtype = DT_REG; 200 } 201 202out_reparse: 203 /* non-unix readdir doesn't provide nlink */ 204 fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK; 205 206 if (fattr->cf_cifsattrs & ATTR_READONLY) 207 fattr->cf_mode &= ~S_IWUGO; 208 209 /* 210 * We of course don't get ACL info in FIND_FIRST/NEXT results, so 211 * mark it for revalidation so that "ls -l" will look right. It might 212 * be super-slow, but if we don't do this then the ownership of files 213 * may look wrong since the inodes may not have timed out by the time 214 * "ls" does a stat() call on them. 215 */ 216 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) || 217 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) 218 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; 219 220 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL && 221 fattr->cf_cifsattrs & ATTR_SYSTEM) { 222 if (fattr->cf_eof == 0) { 223 fattr->cf_mode &= ~S_IFMT; 224 fattr->cf_mode |= S_IFIFO; 225 fattr->cf_dtype = DT_FIFO; 226 } else { 227 /* 228 * trying to get the type and mode via SFU can be slow, 229 * so just call those regular files for now, and mark 230 * for reval 231 */ 232 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; 233 } 234 } 235} 236 237/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */ 238static void 239cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info, 240 struct cifs_sb_info *cifs_sb) 241{ 242 struct smb2_posix_info_parsed parsed; 243 244 posix_info_parse(info, NULL, &parsed); 245 246 memset(fattr, 0, sizeof(*fattr)); 247 fattr->cf_uniqueid = le64_to_cpu(info->Inode); 248 fattr->cf_bytes = le64_to_cpu(info->AllocationSize); 249 fattr->cf_eof = le64_to_cpu(info->EndOfFile); 250 251 fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime); 252 fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime); 253 fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime); 254 255 fattr->cf_nlink = le32_to_cpu(info->HardLinks); 256 fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes); 257 258 /* 259 * Since we set the inode type below we need to mask off 260 * to avoid strange results if bits set above. 261 * XXX: why not make server&client use the type bits? 262 */ 263 fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT; 264 265 cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n", 266 le32_to_cpu(info->DeviceId), 267 le32_to_cpu(info->ReparseTag), 268 le32_to_cpu(info->Mode)); 269 270 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) { 271 fattr->cf_mode |= S_IFDIR; 272 fattr->cf_dtype = DT_DIR; 273 } else { 274 /* 275 * mark anything that is not a dir as regular 276 * file. special files should have the REPARSE 277 * attribute and will be marked as needing revaluation 278 */ 279 fattr->cf_mode |= S_IFREG; 280 fattr->cf_dtype = DT_REG; 281 } 282 283 sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER); 284 sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP); 285} 286 287static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info) 288{ 289 const FILE_DIRECTORY_INFO *fi = info; 290 291 memset(fattr, 0, sizeof(*fattr)); 292 fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes); 293 fattr->cf_eof = le64_to_cpu(fi->EndOfFile); 294 fattr->cf_bytes = le64_to_cpu(fi->AllocationSize); 295 fattr->cf_createtime = le64_to_cpu(fi->CreationTime); 296 fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime); 297 fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime); 298 fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime); 299} 300 301void 302cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info, 303 struct cifs_sb_info *cifs_sb) 304{ 305 __dir_info_to_fattr(fattr, info); 306 cifs_fill_common_info(fattr, cifs_sb); 307} 308 309static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr, 310 const void *info, 311 struct cifs_sb_info *cifs_sb) 312{ 313 const FILE_FULL_DIRECTORY_INFO *di = info; 314 315 __dir_info_to_fattr(fattr, info); 316 317 /* See MS-FSCC 2.4.14, 2.4.19 */ 318 if (fattr->cf_cifsattrs & ATTR_REPARSE) 319 fattr->cf_cifstag = le32_to_cpu(di->EaSize); 320 cifs_fill_common_info(fattr, cifs_sb); 321} 322 323static void 324cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info, 325 struct cifs_sb_info *cifs_sb) 326{ 327 int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj; 328 329 memset(fattr, 0, sizeof(*fattr)); 330 fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate, 331 info->LastAccessTime, offset); 332 fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate, 333 info->LastWriteTime, offset); 334 fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate, 335 info->LastWriteTime, offset); 336 337 fattr->cf_cifsattrs = le16_to_cpu(info->Attributes); 338 fattr->cf_bytes = le32_to_cpu(info->AllocationSize); 339 fattr->cf_eof = le32_to_cpu(info->DataSize); 340 341 cifs_fill_common_info(fattr, cifs_sb); 342} 343 344static int 345_initiate_cifs_search(const unsigned int xid, struct file *file, 346 const char *full_path) 347{ 348 __u16 search_flags; 349 int rc = 0; 350 struct cifsFileInfo *cifsFile; 351 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); 352 struct tcon_link *tlink = NULL; 353 struct cifs_tcon *tcon; 354 struct TCP_Server_Info *server; 355 356 if (file->private_data == NULL) { 357 tlink = cifs_sb_tlink(cifs_sb); 358 if (IS_ERR(tlink)) 359 return PTR_ERR(tlink); 360 361 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL); 362 if (cifsFile == NULL) { 363 rc = -ENOMEM; 364 goto error_exit; 365 } 366 spin_lock_init(&cifsFile->file_info_lock); 367 file->private_data = cifsFile; 368 cifsFile->tlink = cifs_get_tlink(tlink); 369 tcon = tlink_tcon(tlink); 370 } else { 371 cifsFile = file->private_data; 372 tcon = tlink_tcon(cifsFile->tlink); 373 } 374 375 server = tcon->ses->server; 376 377 if (!server->ops->query_dir_first) { 378 rc = -ENOSYS; 379 goto error_exit; 380 } 381 382 cifsFile->invalidHandle = true; 383 cifsFile->srch_inf.endOfSearch = false; 384 385 cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos); 386 387ffirst_retry: 388 /* test for Unix extensions */ 389 /* but now check for them on the share/mount not on the SMB session */ 390 /* if (cap_unix(tcon->ses) { */ 391 if (tcon->unix_ext) 392 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX; 393 else if (tcon->posix_extensions) 394 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO; 395 else if ((tcon->ses->capabilities & 396 tcon->ses->server->vals->cap_nt_find) == 0) { 397 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD; 398 } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 399 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO; 400 } else /* not srvinos - BB fixme add check for backlevel? */ { 401 cifsFile->srch_inf.info_level = SMB_FIND_FILE_FULL_DIRECTORY_INFO; 402 } 403 404 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME; 405 if (backup_cred(cifs_sb)) 406 search_flags |= CIFS_SEARCH_BACKUP_SEARCH; 407 408 rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb, 409 &cifsFile->fid, search_flags, 410 &cifsFile->srch_inf); 411 412 if (rc == 0) { 413 cifsFile->invalidHandle = false; 414 } else if ((rc == -EOPNOTSUPP) && 415 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) { 416 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 417 goto ffirst_retry; 418 } 419error_exit: 420 cifs_put_tlink(tlink); 421 return rc; 422} 423 424static int 425initiate_cifs_search(const unsigned int xid, struct file *file, 426 const char *full_path) 427{ 428 int rc, retry_count = 0; 429 430 do { 431 rc = _initiate_cifs_search(xid, file, full_path); 432 /* 433 * If we don't have enough credits to start reading the 434 * directory just try again after short wait. 435 */ 436 if (rc != -EDEADLK) 437 break; 438 439 usleep_range(512, 2048); 440 } while (retry_count++ < 5); 441 442 return rc; 443} 444 445/* return length of unicode string in bytes */ 446static int cifs_unicode_bytelen(const char *str) 447{ 448 int len; 449 const __le16 *ustr = (const __le16 *)str; 450 451 for (len = 0; len <= PATH_MAX; len++) { 452 if (ustr[len] == 0) 453 return len << 1; 454 } 455 cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n"); 456 return len << 1; 457} 458 459static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level) 460{ 461 char *new_entry; 462 FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry; 463 464 if (level == SMB_FIND_FILE_INFO_STANDARD) { 465 FIND_FILE_STANDARD_INFO *pfData; 466 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo; 467 468 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 + 469 pfData->FileNameLength; 470 } else { 471 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset); 472 473 if (old_entry + next_offset < old_entry) { 474 cifs_dbg(VFS, "Invalid offset %u\n", next_offset); 475 return NULL; 476 } 477 new_entry = old_entry + next_offset; 478 } 479 cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry); 480 /* validate that new_entry is not past end of SMB */ 481 if (new_entry >= end_of_smb) { 482 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n", 483 new_entry, end_of_smb, old_entry); 484 return NULL; 485 } else if (((level == SMB_FIND_FILE_INFO_STANDARD) && 486 (new_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 > end_of_smb)) 487 || ((level != SMB_FIND_FILE_INFO_STANDARD) && 488 (new_entry + sizeof(FILE_DIRECTORY_INFO) + 1 > end_of_smb))) { 489 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n", 490 new_entry, end_of_smb); 491 return NULL; 492 } else 493 return new_entry; 494 495} 496 497struct cifs_dirent { 498 const char *name; 499 size_t namelen; 500 u32 resume_key; 501 u64 ino; 502}; 503 504static void cifs_fill_dirent_posix(struct cifs_dirent *de, 505 const struct smb2_posix_info *info) 506{ 507 struct smb2_posix_info_parsed parsed; 508 509 /* payload should have already been checked at this point */ 510 if (posix_info_parse(info, NULL, &parsed) < 0) { 511 cifs_dbg(VFS, "Invalid POSIX info payload\n"); 512 return; 513 } 514 515 de->name = parsed.name; 516 de->namelen = parsed.name_len; 517 de->resume_key = info->Ignored; 518 de->ino = le64_to_cpu(info->Inode); 519} 520 521static void cifs_fill_dirent_unix(struct cifs_dirent *de, 522 const FILE_UNIX_INFO *info, bool is_unicode) 523{ 524 de->name = &info->FileName[0]; 525 if (is_unicode) 526 de->namelen = cifs_unicode_bytelen(de->name); 527 else 528 de->namelen = strnlen(de->name, PATH_MAX); 529 de->resume_key = info->ResumeKey; 530 de->ino = le64_to_cpu(info->basic.UniqueId); 531} 532 533static void cifs_fill_dirent_dir(struct cifs_dirent *de, 534 const FILE_DIRECTORY_INFO *info) 535{ 536 de->name = &info->FileName[0]; 537 de->namelen = le32_to_cpu(info->FileNameLength); 538 de->resume_key = info->FileIndex; 539} 540 541static void cifs_fill_dirent_full(struct cifs_dirent *de, 542 const FILE_FULL_DIRECTORY_INFO *info) 543{ 544 de->name = &info->FileName[0]; 545 de->namelen = le32_to_cpu(info->FileNameLength); 546 de->resume_key = info->FileIndex; 547} 548 549static void cifs_fill_dirent_search(struct cifs_dirent *de, 550 const SEARCH_ID_FULL_DIR_INFO *info) 551{ 552 de->name = &info->FileName[0]; 553 de->namelen = le32_to_cpu(info->FileNameLength); 554 de->resume_key = info->FileIndex; 555 de->ino = le64_to_cpu(info->UniqueId); 556} 557 558static void cifs_fill_dirent_both(struct cifs_dirent *de, 559 const FILE_BOTH_DIRECTORY_INFO *info) 560{ 561 de->name = &info->FileName[0]; 562 de->namelen = le32_to_cpu(info->FileNameLength); 563 de->resume_key = info->FileIndex; 564} 565 566static void cifs_fill_dirent_std(struct cifs_dirent *de, 567 const FIND_FILE_STANDARD_INFO *info) 568{ 569 de->name = &info->FileName[0]; 570 /* one byte length, no endianess conversion */ 571 de->namelen = info->FileNameLength; 572 de->resume_key = info->ResumeKey; 573} 574 575static int cifs_fill_dirent(struct cifs_dirent *de, const void *info, 576 u16 level, bool is_unicode) 577{ 578 memset(de, 0, sizeof(*de)); 579 580 switch (level) { 581 case SMB_FIND_FILE_POSIX_INFO: 582 cifs_fill_dirent_posix(de, info); 583 break; 584 case SMB_FIND_FILE_UNIX: 585 cifs_fill_dirent_unix(de, info, is_unicode); 586 break; 587 case SMB_FIND_FILE_DIRECTORY_INFO: 588 cifs_fill_dirent_dir(de, info); 589 break; 590 case SMB_FIND_FILE_FULL_DIRECTORY_INFO: 591 cifs_fill_dirent_full(de, info); 592 break; 593 case SMB_FIND_FILE_ID_FULL_DIR_INFO: 594 cifs_fill_dirent_search(de, info); 595 break; 596 case SMB_FIND_FILE_BOTH_DIRECTORY_INFO: 597 cifs_fill_dirent_both(de, info); 598 break; 599 case SMB_FIND_FILE_INFO_STANDARD: 600 cifs_fill_dirent_std(de, info); 601 break; 602 default: 603 cifs_dbg(FYI, "Unknown findfirst level %d\n", level); 604 return -EINVAL; 605 } 606 607 return 0; 608} 609 610#define UNICODE_DOT cpu_to_le16(0x2e) 611 612/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */ 613static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode) 614{ 615 int rc = 0; 616 617 if (!de->name) 618 return 0; 619 620 if (is_unicode) { 621 __le16 *ufilename = (__le16 *)de->name; 622 if (de->namelen == 2) { 623 /* check for . */ 624 if (ufilename[0] == UNICODE_DOT) 625 rc = 1; 626 } else if (de->namelen == 4) { 627 /* check for .. */ 628 if (ufilename[0] == UNICODE_DOT && 629 ufilename[1] == UNICODE_DOT) 630 rc = 2; 631 } 632 } else /* ASCII */ { 633 if (de->namelen == 1) { 634 if (de->name[0] == '.') 635 rc = 1; 636 } else if (de->namelen == 2) { 637 if (de->name[0] == '.' && de->name[1] == '.') 638 rc = 2; 639 } 640 } 641 642 return rc; 643} 644 645/* Check if directory that we are searching has changed so we can decide 646 whether we can use the cached search results from the previous search */ 647static int is_dir_changed(struct file *file) 648{ 649 struct inode *inode = file_inode(file); 650 struct cifsInodeInfo *cifsInfo = CIFS_I(inode); 651 652 if (cifsInfo->time == 0) 653 return 1; /* directory was changed, perhaps due to unlink */ 654 else 655 return 0; 656 657} 658 659static int cifs_save_resume_key(const char *current_entry, 660 struct cifsFileInfo *file_info) 661{ 662 struct cifs_dirent de; 663 int rc; 664 665 rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level, 666 file_info->srch_inf.unicode); 667 if (!rc) { 668 file_info->srch_inf.presume_name = de.name; 669 file_info->srch_inf.resume_name_len = de.namelen; 670 file_info->srch_inf.resume_key = de.resume_key; 671 } 672 return rc; 673} 674 675/* 676 * Find the corresponding entry in the search. Note that the SMB server returns 677 * search entries for . and .. which complicates logic here if we choose to 678 * parse for them and we do not assume that they are located in the findfirst 679 * return buffer. We start counting in the buffer with entry 2 and increment for 680 * every entry (do not increment for . or .. entry). 681 */ 682static int 683find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos, 684 struct file *file, const char *full_path, 685 char **current_entry, int *num_to_ret) 686{ 687 __u16 search_flags; 688 int rc = 0; 689 int pos_in_buf = 0; 690 loff_t first_entry_in_buffer; 691 loff_t index_to_find = pos; 692 struct cifsFileInfo *cfile = file->private_data; 693 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); 694 struct TCP_Server_Info *server = tcon->ses->server; 695 /* check if index in the buffer */ 696 697 if (!server->ops->query_dir_first || !server->ops->query_dir_next) 698 return -ENOSYS; 699 700 if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL)) 701 return -ENOENT; 702 703 *current_entry = NULL; 704 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry - 705 cfile->srch_inf.entries_in_buffer; 706 707 /* 708 * If first entry in buf is zero then is first buffer 709 * in search response data which means it is likely . and .. 710 * will be in this buffer, although some servers do not return 711 * . and .. for the root of a drive and for those we need 712 * to start two entries earlier. 713 */ 714 715 dump_cifs_file_struct(file, "In fce "); 716 if (((index_to_find < cfile->srch_inf.index_of_last_entry) && 717 is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) { 718 /* close and restart search */ 719 cifs_dbg(FYI, "search backing up - close and restart search\n"); 720 spin_lock(&cfile->file_info_lock); 721 if (server->ops->dir_needs_close(cfile)) { 722 cfile->invalidHandle = true; 723 spin_unlock(&cfile->file_info_lock); 724 if (server->ops->close_dir) 725 server->ops->close_dir(xid, tcon, &cfile->fid); 726 } else 727 spin_unlock(&cfile->file_info_lock); 728 if (cfile->srch_inf.ntwrk_buf_start) { 729 cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n"); 730 if (cfile->srch_inf.smallBuf) 731 cifs_small_buf_release(cfile->srch_inf. 732 ntwrk_buf_start); 733 else 734 cifs_buf_release(cfile->srch_inf. 735 ntwrk_buf_start); 736 cfile->srch_inf.ntwrk_buf_start = NULL; 737 } 738 rc = initiate_cifs_search(xid, file, full_path); 739 if (rc) { 740 cifs_dbg(FYI, "error %d reinitiating a search on rewind\n", 741 rc); 742 return rc; 743 } 744 /* FindFirst/Next set last_entry to NULL on malformed reply */ 745 if (cfile->srch_inf.last_entry) 746 cifs_save_resume_key(cfile->srch_inf.last_entry, cfile); 747 } 748 749 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME; 750 if (backup_cred(cifs_sb)) 751 search_flags |= CIFS_SEARCH_BACKUP_SEARCH; 752 753 while ((index_to_find >= cfile->srch_inf.index_of_last_entry) && 754 (rc == 0) && !cfile->srch_inf.endOfSearch) { 755 cifs_dbg(FYI, "calling findnext2\n"); 756 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid, 757 search_flags, 758 &cfile->srch_inf); 759 /* FindFirst/Next set last_entry to NULL on malformed reply */ 760 if (cfile->srch_inf.last_entry) 761 cifs_save_resume_key(cfile->srch_inf.last_entry, cfile); 762 if (rc) 763 return -ENOENT; 764 } 765 if (index_to_find < cfile->srch_inf.index_of_last_entry) { 766 /* we found the buffer that contains the entry */ 767 /* scan and find it */ 768 int i; 769 char *cur_ent; 770 char *end_of_smb; 771 772 if (cfile->srch_inf.ntwrk_buf_start == NULL) { 773 cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n"); 774 return -EIO; 775 } 776 777 end_of_smb = cfile->srch_inf.ntwrk_buf_start + 778 server->ops->calc_smb_size( 779 cfile->srch_inf.ntwrk_buf_start); 780 781 cur_ent = cfile->srch_inf.srch_entries_start; 782 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry 783 - cfile->srch_inf.entries_in_buffer; 784 pos_in_buf = index_to_find - first_entry_in_buffer; 785 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf); 786 787 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) { 788 /* go entry by entry figuring out which is first */ 789 cur_ent = nxt_dir_entry(cur_ent, end_of_smb, 790 cfile->srch_inf.info_level); 791 } 792 if ((cur_ent == NULL) && (i < pos_in_buf)) { 793 /* BB fixme - check if we should flag this error */ 794 cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n", 795 pos_in_buf, index_to_find, rc); 796 } 797 rc = 0; 798 *current_entry = cur_ent; 799 } else { 800 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n"); 801 return 0; 802 } 803 804 if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) { 805 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n"); 806 *num_to_ret = 0; 807 } else 808 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf; 809 810 return rc; 811} 812 813static bool emit_cached_dirents(struct cached_dirents *cde, 814 struct dir_context *ctx) 815{ 816 struct cached_dirent *dirent; 817 bool rc; 818 819 list_for_each_entry(dirent, &cde->entries, entry) { 820 /* 821 * Skip all early entries prior to the current lseek() 822 * position. 823 */ 824 if (ctx->pos > dirent->pos) 825 continue; 826 /* 827 * We recorded the current ->pos value for the dirent 828 * when we stored it in the cache. 829 * However, this sequence of ->pos values may have holes 830 * in it, for example dot-dirs returned from the server 831 * are suppressed. 832 * Handle this bu forcing ctx->pos to be the same as the 833 * ->pos of the current dirent we emit from the cache. 834 * This means that when we emit these entries from the cache 835 * we now emit them with the same ->pos value as in the 836 * initial scan. 837 */ 838 ctx->pos = dirent->pos; 839 rc = dir_emit(ctx, dirent->name, dirent->namelen, 840 dirent->fattr.cf_uniqueid, 841 dirent->fattr.cf_dtype); 842 if (!rc) 843 return rc; 844 ctx->pos++; 845 } 846 return true; 847} 848 849static void update_cached_dirents_count(struct cached_dirents *cde, 850 struct dir_context *ctx) 851{ 852 if (cde->ctx != ctx) 853 return; 854 if (cde->is_valid || cde->is_failed) 855 return; 856 857 cde->pos++; 858} 859 860static void finished_cached_dirents_count(struct cached_dirents *cde, 861 struct dir_context *ctx) 862{ 863 if (cde->ctx != ctx) 864 return; 865 if (cde->is_valid || cde->is_failed) 866 return; 867 if (ctx->pos != cde->pos) 868 return; 869 870 cde->is_valid = 1; 871} 872 873static void add_cached_dirent(struct cached_dirents *cde, 874 struct dir_context *ctx, 875 const char *name, int namelen, 876 struct cifs_fattr *fattr) 877{ 878 struct cached_dirent *de; 879 880 if (cde->ctx != ctx) 881 return; 882 if (cde->is_valid || cde->is_failed) 883 return; 884 if (ctx->pos != cde->pos) { 885 cde->is_failed = 1; 886 return; 887 } 888 de = kzalloc(sizeof(*de), GFP_ATOMIC); 889 if (de == NULL) { 890 cde->is_failed = 1; 891 return; 892 } 893 de->namelen = namelen; 894 de->name = kstrndup(name, namelen, GFP_ATOMIC); 895 if (de->name == NULL) { 896 kfree(de); 897 cde->is_failed = 1; 898 return; 899 } 900 de->pos = ctx->pos; 901 902 memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr)); 903 904 list_add_tail(&de->entry, &cde->entries); 905} 906 907static bool cifs_dir_emit(struct dir_context *ctx, 908 const char *name, int namelen, 909 struct cifs_fattr *fattr, 910 struct cached_fid *cfid) 911{ 912 bool rc; 913 ino_t ino = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid); 914 915 rc = dir_emit(ctx, name, namelen, ino, fattr->cf_dtype); 916 if (!rc) 917 return rc; 918 919 if (cfid) { 920 mutex_lock(&cfid->dirents.de_mutex); 921 add_cached_dirent(&cfid->dirents, ctx, name, namelen, 922 fattr); 923 mutex_unlock(&cfid->dirents.de_mutex); 924 } 925 926 return rc; 927} 928 929static int cifs_filldir(char *find_entry, struct file *file, 930 struct dir_context *ctx, 931 char *scratch_buf, unsigned int max_len, 932 struct cached_fid *cfid) 933{ 934 struct cifsFileInfo *file_info = file->private_data; 935 struct super_block *sb = file_inode(file)->i_sb; 936 struct cifs_sb_info *cifs_sb = CIFS_SB(sb); 937 struct cifs_dirent de = { NULL, }; 938 struct cifs_fattr fattr; 939 struct qstr name; 940 int rc = 0; 941 942 rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level, 943 file_info->srch_inf.unicode); 944 if (rc) 945 return rc; 946 947 if (de.namelen > max_len) { 948 cifs_dbg(VFS, "bad search response length %zd past smb end\n", 949 de.namelen); 950 return -EINVAL; 951 } 952 953 /* skip . and .. since we added them first */ 954 if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode)) 955 return 0; 956 957 if (file_info->srch_inf.unicode) { 958 struct nls_table *nlt = cifs_sb->local_nls; 959 int map_type; 960 961 map_type = cifs_remap(cifs_sb); 962 name.name = scratch_buf; 963 name.len = 964 cifs_from_utf16((char *)name.name, (__le16 *)de.name, 965 UNICODE_NAME_MAX, 966 min_t(size_t, de.namelen, 967 (size_t)max_len), nlt, map_type); 968 name.len -= nls_nullsize(nlt); 969 } else { 970 name.name = de.name; 971 name.len = de.namelen; 972 } 973 974 switch (file_info->srch_inf.info_level) { 975 case SMB_FIND_FILE_POSIX_INFO: 976 cifs_posix_to_fattr(&fattr, 977 (struct smb2_posix_info *)find_entry, 978 cifs_sb); 979 break; 980 case SMB_FIND_FILE_UNIX: 981 cifs_unix_basic_to_fattr(&fattr, 982 &((FILE_UNIX_INFO *)find_entry)->basic, 983 cifs_sb); 984 if (S_ISLNK(fattr.cf_mode)) 985 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL; 986 break; 987 case SMB_FIND_FILE_INFO_STANDARD: 988 cifs_std_info_to_fattr(&fattr, 989 (FIND_FILE_STANDARD_INFO *)find_entry, 990 cifs_sb); 991 break; 992 case SMB_FIND_FILE_FULL_DIRECTORY_INFO: 993 case SMB_FIND_FILE_ID_FULL_DIR_INFO: 994 cifs_fulldir_info_to_fattr(&fattr, find_entry, cifs_sb); 995 break; 996 default: 997 cifs_dir_info_to_fattr(&fattr, 998 (FILE_DIRECTORY_INFO *)find_entry, 999 cifs_sb); 1000 break; 1001 } 1002 1003 if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) { 1004 fattr.cf_uniqueid = de.ino; 1005 } else { 1006 fattr.cf_uniqueid = iunique(sb, ROOT_I); 1007 cifs_autodisable_serverino(cifs_sb); 1008 } 1009 1010 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) && 1011 couldbe_mf_symlink(&fattr)) 1012 /* 1013 * trying to get the type and mode can be slow, 1014 * so just call those regular files for now, and mark 1015 * for reval 1016 */ 1017 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL; 1018 1019 cifs_prime_dcache(file_dentry(file), &name, &fattr); 1020 1021 return !cifs_dir_emit(ctx, name.name, name.len, 1022 &fattr, cfid); 1023} 1024 1025 1026int cifs_readdir(struct file *file, struct dir_context *ctx) 1027{ 1028 int rc = 0; 1029 unsigned int xid; 1030 int i; 1031 struct tcon_link *tlink = NULL; 1032 struct cifs_tcon *tcon; 1033 struct cifsFileInfo *cifsFile; 1034 char *current_entry; 1035 int num_to_fill = 0; 1036 char *tmp_buf = NULL; 1037 char *end_of_smb; 1038 unsigned int max_len; 1039 const char *full_path; 1040 void *page = alloc_dentry_path(); 1041 struct cached_fid *cfid = NULL; 1042 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); 1043 1044 xid = get_xid(); 1045 1046 full_path = build_path_from_dentry(file_dentry(file), page); 1047 if (IS_ERR(full_path)) { 1048 rc = PTR_ERR(full_path); 1049 goto rddir2_exit; 1050 } 1051 1052 if (file->private_data == NULL) { 1053 tlink = cifs_sb_tlink(cifs_sb); 1054 if (IS_ERR(tlink)) 1055 goto cache_not_found; 1056 tcon = tlink_tcon(tlink); 1057 } else { 1058 cifsFile = file->private_data; 1059 tcon = tlink_tcon(cifsFile->tlink); 1060 } 1061 1062 rc = open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid); 1063 cifs_put_tlink(tlink); 1064 if (rc) 1065 goto cache_not_found; 1066 1067 mutex_lock(&cfid->dirents.de_mutex); 1068 /* 1069 * If this was reading from the start of the directory 1070 * we need to initialize scanning and storing the 1071 * directory content. 1072 */ 1073 if (ctx->pos == 0 && cfid->dirents.ctx == NULL) { 1074 cfid->dirents.ctx = ctx; 1075 cfid->dirents.pos = 2; 1076 } 1077 /* 1078 * If we already have the entire directory cached then 1079 * we can just serve the cache. 1080 */ 1081 if (cfid->dirents.is_valid) { 1082 if (!dir_emit_dots(file, ctx)) { 1083 mutex_unlock(&cfid->dirents.de_mutex); 1084 goto rddir2_exit; 1085 } 1086 emit_cached_dirents(&cfid->dirents, ctx); 1087 mutex_unlock(&cfid->dirents.de_mutex); 1088 goto rddir2_exit; 1089 } 1090 mutex_unlock(&cfid->dirents.de_mutex); 1091 1092 /* Drop the cache while calling initiate_cifs_search and 1093 * find_cifs_entry in case there will be reconnects during 1094 * query_directory. 1095 */ 1096 close_cached_dir(cfid); 1097 cfid = NULL; 1098 1099 cache_not_found: 1100 /* 1101 * Ensure FindFirst doesn't fail before doing filldir() for '.' and 1102 * '..'. Otherwise we won't be able to notify VFS in case of failure. 1103 */ 1104 if (file->private_data == NULL) { 1105 rc = initiate_cifs_search(xid, file, full_path); 1106 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc); 1107 if (rc) 1108 goto rddir2_exit; 1109 } 1110 1111 if (!dir_emit_dots(file, ctx)) 1112 goto rddir2_exit; 1113 1114 /* 1) If search is active, 1115 is in current search buffer? 1116 if it before then restart search 1117 if after then keep searching till find it */ 1118 cifsFile = file->private_data; 1119 if (cifsFile->srch_inf.endOfSearch) { 1120 if (cifsFile->srch_inf.emptyDir) { 1121 cifs_dbg(FYI, "End of search, empty dir\n"); 1122 rc = 0; 1123 goto rddir2_exit; 1124 } 1125 } /* else { 1126 cifsFile->invalidHandle = true; 1127 tcon->ses->server->close(xid, tcon, &cifsFile->fid); 1128 } */ 1129 1130 tcon = tlink_tcon(cifsFile->tlink); 1131 rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path, 1132 ¤t_entry, &num_to_fill); 1133 open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid); 1134 if (rc) { 1135 cifs_dbg(FYI, "fce error %d\n", rc); 1136 goto rddir2_exit; 1137 } else if (current_entry != NULL) { 1138 cifs_dbg(FYI, "entry %lld found\n", ctx->pos); 1139 } else { 1140 if (cfid) { 1141 mutex_lock(&cfid->dirents.de_mutex); 1142 finished_cached_dirents_count(&cfid->dirents, ctx); 1143 mutex_unlock(&cfid->dirents.de_mutex); 1144 } 1145 cifs_dbg(FYI, "Could not find entry\n"); 1146 goto rddir2_exit; 1147 } 1148 cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n", 1149 num_to_fill, cifsFile->srch_inf.ntwrk_buf_start); 1150 max_len = tcon->ses->server->ops->calc_smb_size( 1151 cifsFile->srch_inf.ntwrk_buf_start); 1152 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len; 1153 1154 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL); 1155 if (tmp_buf == NULL) { 1156 rc = -ENOMEM; 1157 goto rddir2_exit; 1158 } 1159 1160 for (i = 0; i < num_to_fill; i++) { 1161 if (current_entry == NULL) { 1162 /* evaluate whether this case is an error */ 1163 cifs_dbg(VFS, "past SMB end, num to fill %d i %d\n", 1164 num_to_fill, i); 1165 break; 1166 } 1167 /* 1168 * if buggy server returns . and .. late do we want to 1169 * check for that here? 1170 */ 1171 *tmp_buf = 0; 1172 rc = cifs_filldir(current_entry, file, ctx, 1173 tmp_buf, max_len, cfid); 1174 if (rc) { 1175 if (rc > 0) 1176 rc = 0; 1177 break; 1178 } 1179 1180 ctx->pos++; 1181 if (cfid) { 1182 mutex_lock(&cfid->dirents.de_mutex); 1183 update_cached_dirents_count(&cfid->dirents, ctx); 1184 mutex_unlock(&cfid->dirents.de_mutex); 1185 } 1186 1187 if (ctx->pos == 1188 cifsFile->srch_inf.index_of_last_entry) { 1189 cifs_dbg(FYI, "last entry in buf at pos %lld %s\n", 1190 ctx->pos, tmp_buf); 1191 cifs_save_resume_key(current_entry, cifsFile); 1192 break; 1193 } 1194 current_entry = 1195 nxt_dir_entry(current_entry, end_of_smb, 1196 cifsFile->srch_inf.info_level); 1197 } 1198 kfree(tmp_buf); 1199 1200rddir2_exit: 1201 if (cfid) 1202 close_cached_dir(cfid); 1203 free_dentry_path(page); 1204 free_xid(xid); 1205 return rc; 1206} 1207