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