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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 bool posix = cifs_sb_master_tcon(cifs_sb)->posix_extensions;
75 bool reparse_need_reval = false;
76 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
77 int rc;
78
79 cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
80
81 dentry = d_hash_and_lookup(parent, name);
82 if (!dentry) {
83 /*
84 * If we know that the inode will need to be revalidated
85 * immediately, then don't create a new dentry for it.
86 * We'll end up doing an on the wire call either way and
87 * this spares us an invalidation.
88 */
89retry:
90 if (posix) {
91 switch (fattr->cf_mode & S_IFMT) {
92 case S_IFLNK:
93 case S_IFBLK:
94 case S_IFCHR:
95 reparse_need_reval = true;
96 break;
97 default:
98 break;
99 }
100 } else if (fattr->cf_cifsattrs & ATTR_REPARSE) {
101 reparse_need_reval = true;
102 }
103
104 if (reparse_need_reval ||
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 some existing attributes when
137 * reparse tag and ctime haven't changed.
138 */
139 rc = 0;
140 if (fattr->cf_cifsattrs & ATTR_REPARSE) {
141 if (likely(reparse_inode_match(inode, fattr))) {
142 fattr->cf_mode = inode->i_mode;
143 fattr->cf_rdev = inode->i_rdev;
144 fattr->cf_uid = inode->i_uid;
145 fattr->cf_gid = inode->i_gid;
146 fattr->cf_eof = CIFS_I(inode)->netfs.remote_i_size;
147 fattr->cf_symlink_target = NULL;
148 } else {
149 CIFS_I(inode)->time = 0;
150 rc = -ESTALE;
151 }
152 }
153 if (!rc && !cifs_fattr_to_inode(inode, fattr, true)) {
154 dput(dentry);
155 return;
156 }
157 }
158 }
159 d_invalidate(dentry);
160 dput(dentry);
161 goto retry;
162 } else {
163 inode = cifs_iget(sb, fattr);
164 if (!inode)
165 inode = ERR_PTR(-ENOMEM);
166 alias = d_splice_alias(inode, dentry);
167 d_lookup_done(dentry);
168 if (alias && !IS_ERR(alias))
169 dput(alias);
170 }
171 dput(dentry);
172}
173
174static void
175cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
176{
177 struct cifs_open_info_data data = {
178 .reparse = { .tag = fattr->cf_cifstag, },
179 };
180
181 fattr->cf_uid = cifs_sb->ctx->linux_uid;
182 fattr->cf_gid = cifs_sb->ctx->linux_gid;
183
184 /*
185 * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
186 * are preferred by the Linux client in some cases since, unlike
187 * the NFS reparse tag (or EAs), they don't require an extra query
188 * to determine which type of special file they represent.
189 * TODO: go through all documented reparse tags to see if we can
190 * reasonably map some of them to directories vs. files vs. symlinks
191 */
192 if ((fattr->cf_cifsattrs & ATTR_REPARSE) &&
193 cifs_reparse_point_to_fattr(cifs_sb, fattr, &data))
194 goto out_reparse;
195
196 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
197 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
198 fattr->cf_dtype = DT_DIR;
199 } else {
200 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
201 fattr->cf_dtype = DT_REG;
202 }
203
204out_reparse:
205 /* non-unix readdir doesn't provide nlink */
206 fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
207
208 if (fattr->cf_cifsattrs & ATTR_READONLY)
209 fattr->cf_mode &= ~S_IWUGO;
210
211 /*
212 * We of course don't get ACL info in FIND_FIRST/NEXT results, so
213 * mark it for revalidation so that "ls -l" will look right. It might
214 * be super-slow, but if we don't do this then the ownership of files
215 * may look wrong since the inodes may not have timed out by the time
216 * "ls" does a stat() call on them.
217 */
218 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
219 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
220 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
221
222 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
223 fattr->cf_cifsattrs & ATTR_SYSTEM) {
224 if (fattr->cf_eof == 0) {
225 fattr->cf_mode &= ~S_IFMT;
226 fattr->cf_mode |= S_IFIFO;
227 fattr->cf_dtype = DT_FIFO;
228 } else {
229 /*
230 * trying to get the type and mode via SFU can be slow,
231 * so just call those regular files for now, and mark
232 * for reval
233 */
234 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
235 }
236 }
237}
238
239/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
240static void
241cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
242 struct cifs_sb_info *cifs_sb)
243{
244 struct smb2_posix_info_parsed parsed;
245
246 posix_info_parse(info, NULL, &parsed);
247
248 memset(fattr, 0, sizeof(*fattr));
249 fattr->cf_uniqueid = le64_to_cpu(info->Inode);
250 fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
251 fattr->cf_eof = le64_to_cpu(info->EndOfFile);
252
253 fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
254 fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
255 fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
256
257 fattr->cf_nlink = le32_to_cpu(info->HardLinks);
258 fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
259
260 if (fattr->cf_cifsattrs & ATTR_REPARSE)
261 fattr->cf_cifstag = le32_to_cpu(info->ReparseTag);
262
263 /* The Mode field in the response can now include the file type as well */
264 fattr->cf_mode = wire_mode_to_posix(le32_to_cpu(info->Mode),
265 fattr->cf_cifsattrs & ATTR_DIRECTORY);
266 fattr->cf_dtype = S_DT(le32_to_cpu(info->Mode));
267
268 switch (fattr->cf_mode & S_IFMT) {
269 case S_IFLNK:
270 case S_IFBLK:
271 case S_IFCHR:
272 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
273 break;
274 default:
275 break;
276 }
277
278 cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
279 le32_to_cpu(info->DeviceId),
280 le32_to_cpu(info->ReparseTag),
281 le32_to_cpu(info->Mode));
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_autodisable_serverino(cifs_sb);
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 endianness 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 *cifs_inode_info = CIFS_I(inode);
651
652 if (cifs_inode_info->time == 0)
653 return 1; /* directory was changed, e.g. unlink or new file */
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 by 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}