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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/**
2 * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
3 *
Anton Altaparmakov83311912007-01-18 09:42:48 +00004 * Copyright (c) 2001-2007 Anton Altaparmakov
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * Copyright (c) 2002 Richard Russon
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the Linux-NTFS
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/buffer_head.h>
24
25#include "dir.h"
26#include "aops.h"
27#include "attrib.h"
28#include "mft.h"
29#include "debug.h"
30#include "ntfs.h"
31
32/**
33 * The little endian Unicode string $I30 as a global constant.
34 */
35ntfschar I30[5] = { const_cpu_to_le16('$'), const_cpu_to_le16('I'),
36 const_cpu_to_le16('3'), const_cpu_to_le16('0'), 0 };
37
38/**
39 * ntfs_lookup_inode_by_name - find an inode in a directory given its name
40 * @dir_ni: ntfs inode of the directory in which to search for the name
41 * @uname: Unicode name for which to search in the directory
42 * @uname_len: length of the name @uname in Unicode characters
43 * @res: return the found file name if necessary (see below)
44 *
45 * Look for an inode with name @uname in the directory with inode @dir_ni.
46 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for
47 * the Unicode name. If the name is found in the directory, the corresponding
48 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
49 * is a 64-bit number containing the sequence number.
50 *
51 * On error, a negative value is returned corresponding to the error code. In
52 * particular if the inode is not found -ENOENT is returned. Note that you
53 * can't just check the return value for being negative, you have to check the
54 * inode number for being negative which you can extract using MREC(return
55 * value).
56 *
57 * Note, @uname_len does not include the (optional) terminating NULL character.
58 *
59 * Note, we look for a case sensitive match first but we also look for a case
60 * insensitive match at the same time. If we find a case insensitive match, we
61 * save that for the case that we don't find an exact match, where we return
62 * the case insensitive match and setup @res (which we allocate!) with the mft
63 * reference, the file name type, length and with a copy of the little endian
64 * Unicode file name itself. If we match a file name which is in the DOS name
65 * space, we only return the mft reference and file name type in @res.
66 * ntfs_lookup() then uses this to find the long file name in the inode itself.
67 * This is to avoid polluting the dcache with short file names. We want them to
68 * work but we don't care for how quickly one can access them. This also fixes
69 * the dcache aliasing issues.
70 *
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080071 * Locking: - Caller must hold i_mutex on the directory.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 * - Each page cache page in the index allocation mapping must be
73 * locked whilst being accessed otherwise we may find a corrupt
74 * page due to it being under ->writepage at the moment which
75 * applies the mst protection fixups before writing out and then
76 * removes them again after the write is complete after which it
77 * unlocks the page.
78 */
79MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
80 const int uname_len, ntfs_name **res)
81{
82 ntfs_volume *vol = dir_ni->vol;
83 struct super_block *sb = vol->sb;
84 MFT_RECORD *m;
85 INDEX_ROOT *ir;
86 INDEX_ENTRY *ie;
87 INDEX_ALLOCATION *ia;
88 u8 *index_end;
89 u64 mref;
90 ntfs_attr_search_ctx *ctx;
91 int err, rc;
92 VCN vcn, old_vcn;
93 struct address_space *ia_mapping;
94 struct page *page;
95 u8 *kaddr;
96 ntfs_name *name = NULL;
97
98 BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode));
99 BUG_ON(NInoAttr(dir_ni));
100 /* Get hold of the mft record for the directory. */
101 m = map_mft_record(dir_ni);
102 if (IS_ERR(m)) {
103 ntfs_error(sb, "map_mft_record() failed with error code %ld.",
104 -PTR_ERR(m));
105 return ERR_MREF(PTR_ERR(m));
106 }
107 ctx = ntfs_attr_get_search_ctx(dir_ni, m);
108 if (unlikely(!ctx)) {
109 err = -ENOMEM;
110 goto err_out;
111 }
112 /* Find the index root attribute in the mft record. */
113 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
114 0, ctx);
115 if (unlikely(err)) {
116 if (err == -ENOENT) {
117 ntfs_error(sb, "Index root attribute missing in "
118 "directory inode 0x%lx.",
119 dir_ni->mft_no);
120 err = -EIO;
121 }
122 goto err_out;
123 }
124 /* Get to the index root value (it's been verified in read_inode). */
125 ir = (INDEX_ROOT*)((u8*)ctx->attr +
126 le16_to_cpu(ctx->attr->data.resident.value_offset));
127 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
128 /* The first index entry. */
129 ie = (INDEX_ENTRY*)((u8*)&ir->index +
130 le32_to_cpu(ir->index.entries_offset));
131 /*
132 * Loop until we exceed valid memory (corruption case) or until we
133 * reach the last entry.
134 */
135 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
136 /* Bounds checks. */
137 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie +
138 sizeof(INDEX_ENTRY_HEADER) > index_end ||
139 (u8*)ie + le16_to_cpu(ie->key_length) >
140 index_end)
141 goto dir_err_out;
142 /*
143 * The last entry cannot contain a name. It can however contain
144 * a pointer to a child node in the B+tree so we just break out.
145 */
146 if (ie->flags & INDEX_ENTRY_END)
147 break;
148 /*
149 * We perform a case sensitive comparison and if that matches
150 * we are done and return the mft reference of the inode (i.e.
151 * the inode number together with the sequence number for
152 * consistency checking). We convert it to cpu format before
153 * returning.
154 */
155 if (ntfs_are_names_equal(uname, uname_len,
156 (ntfschar*)&ie->key.file_name.file_name,
157 ie->key.file_name.file_name_length,
158 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
159found_it:
160 /*
161 * We have a perfect match, so we don't need to care
162 * about having matched imperfectly before, so we can
163 * free name and set *res to NULL.
164 * However, if the perfect match is a short file name,
165 * we need to signal this through *res, so that
166 * ntfs_lookup() can fix dcache aliasing issues.
167 * As an optimization we just reuse an existing
168 * allocation of *res.
169 */
170 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
171 if (!name) {
172 name = kmalloc(sizeof(ntfs_name),
173 GFP_NOFS);
174 if (!name) {
175 err = -ENOMEM;
176 goto err_out;
177 }
178 }
179 name->mref = le64_to_cpu(
180 ie->data.dir.indexed_file);
181 name->type = FILE_NAME_DOS;
182 name->len = 0;
183 *res = name;
184 } else {
Jesper Juhl251c8422005-04-04 14:59:56 +0100185 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 *res = NULL;
187 }
188 mref = le64_to_cpu(ie->data.dir.indexed_file);
189 ntfs_attr_put_search_ctx(ctx);
190 unmap_mft_record(dir_ni);
191 return mref;
192 }
193 /*
194 * For a case insensitive mount, we also perform a case
195 * insensitive comparison (provided the file name is not in the
196 * POSIX namespace). If the comparison matches, and the name is
197 * in the WIN32 namespace, we cache the filename in *res so
198 * that the caller, ntfs_lookup(), can work on it. If the
199 * comparison matches, and the name is in the DOS namespace, we
200 * only cache the mft reference and the file name type (we set
201 * the name length to zero for simplicity).
202 */
203 if (!NVolCaseSensitive(vol) &&
204 ie->key.file_name.file_name_type &&
205 ntfs_are_names_equal(uname, uname_len,
206 (ntfschar*)&ie->key.file_name.file_name,
207 ie->key.file_name.file_name_length,
208 IGNORE_CASE, vol->upcase, vol->upcase_len)) {
209 int name_size = sizeof(ntfs_name);
210 u8 type = ie->key.file_name.file_name_type;
211 u8 len = ie->key.file_name.file_name_length;
212
213 /* Only one case insensitive matching name allowed. */
214 if (name) {
215 ntfs_error(sb, "Found already allocated name "
216 "in phase 1. Please run chkdsk "
217 "and if that doesn't find any "
218 "errors please report you saw "
219 "this message to "
220 "linux-ntfs-dev@lists."
221 "sourceforge.net.");
222 goto dir_err_out;
223 }
224
225 if (type != FILE_NAME_DOS)
226 name_size += len * sizeof(ntfschar);
227 name = kmalloc(name_size, GFP_NOFS);
228 if (!name) {
229 err = -ENOMEM;
230 goto err_out;
231 }
232 name->mref = le64_to_cpu(ie->data.dir.indexed_file);
233 name->type = type;
234 if (type != FILE_NAME_DOS) {
235 name->len = len;
236 memcpy(name->name, ie->key.file_name.file_name,
237 len * sizeof(ntfschar));
238 } else
239 name->len = 0;
240 *res = name;
241 }
242 /*
243 * Not a perfect match, need to do full blown collation so we
244 * know which way in the B+tree we have to go.
245 */
246 rc = ntfs_collate_names(uname, uname_len,
247 (ntfschar*)&ie->key.file_name.file_name,
248 ie->key.file_name.file_name_length, 1,
249 IGNORE_CASE, vol->upcase, vol->upcase_len);
250 /*
251 * If uname collates before the name of the current entry, there
252 * is definitely no such name in this index but we might need to
253 * descend into the B+tree so we just break out of the loop.
254 */
255 if (rc == -1)
256 break;
257 /* The names are not equal, continue the search. */
258 if (rc)
259 continue;
260 /*
261 * Names match with case insensitive comparison, now try the
262 * case sensitive comparison, which is required for proper
263 * collation.
264 */
265 rc = ntfs_collate_names(uname, uname_len,
266 (ntfschar*)&ie->key.file_name.file_name,
267 ie->key.file_name.file_name_length, 1,
268 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
269 if (rc == -1)
270 break;
271 if (rc)
272 continue;
273 /*
274 * Perfect match, this will never happen as the
275 * ntfs_are_names_equal() call will have gotten a match but we
276 * still treat it correctly.
277 */
278 goto found_it;
279 }
280 /*
281 * We have finished with this index without success. Check for the
282 * presence of a child node and if not present return -ENOENT, unless
283 * we have got a matching name cached in name in which case return the
284 * mft reference associated with it.
285 */
286 if (!(ie->flags & INDEX_ENTRY_NODE)) {
287 if (name) {
288 ntfs_attr_put_search_ctx(ctx);
289 unmap_mft_record(dir_ni);
290 return name->mref;
291 }
292 ntfs_debug("Entry not found.");
293 err = -ENOENT;
294 goto err_out;
295 } /* Child node present, descend into it. */
296 /* Consistency check: Verify that an index allocation exists. */
297 if (!NInoIndexAllocPresent(dir_ni)) {
298 ntfs_error(sb, "No index allocation attribute but index entry "
299 "requires one. Directory inode 0x%lx is "
300 "corrupt or driver bug.", dir_ni->mft_no);
301 goto err_out;
302 }
303 /* Get the starting vcn of the index_block holding the child node. */
304 vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
305 ia_mapping = VFS_I(dir_ni)->i_mapping;
306 /*
307 * We are done with the index root and the mft record. Release them,
308 * otherwise we deadlock with ntfs_map_page().
309 */
310 ntfs_attr_put_search_ctx(ctx);
311 unmap_mft_record(dir_ni);
312 m = NULL;
313 ctx = NULL;
314descend_into_child_node:
315 /*
316 * Convert vcn to index into the index allocation attribute in units
317 * of PAGE_CACHE_SIZE and map the page cache page, reading it from
318 * disk if necessary.
319 */
320 page = ntfs_map_page(ia_mapping, vcn <<
321 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
322 if (IS_ERR(page)) {
323 ntfs_error(sb, "Failed to map directory index page, error %ld.",
324 -PTR_ERR(page));
325 err = PTR_ERR(page);
326 goto err_out;
327 }
328 lock_page(page);
329 kaddr = (u8*)page_address(page);
330fast_descend_into_child_node:
331 /* Get to the index allocation block. */
332 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
333 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
334 /* Bounds checks. */
335 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
336 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
337 "inode 0x%lx or driver bug.", dir_ni->mft_no);
338 goto unm_err_out;
339 }
340 /* Catch multi sector transfer fixup errors. */
341 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
342 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
343 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
344 (unsigned long long)vcn, dir_ni->mft_no);
345 goto unm_err_out;
346 }
347 if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
348 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
349 "different from expected VCN (0x%llx). "
350 "Directory inode 0x%lx is corrupt or driver "
351 "bug.", (unsigned long long)
352 sle64_to_cpu(ia->index_block_vcn),
353 (unsigned long long)vcn, dir_ni->mft_no);
354 goto unm_err_out;
355 }
356 if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
357 dir_ni->itype.index.block_size) {
358 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
359 "0x%lx has a size (%u) differing from the "
360 "directory specified size (%u). Directory "
361 "inode is corrupt or driver bug.",
362 (unsigned long long)vcn, dir_ni->mft_no,
363 le32_to_cpu(ia->index.allocated_size) + 0x18,
364 dir_ni->itype.index.block_size);
365 goto unm_err_out;
366 }
367 index_end = (u8*)ia + dir_ni->itype.index.block_size;
368 if (index_end > kaddr + PAGE_CACHE_SIZE) {
369 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
370 "0x%lx crosses page boundary. Impossible! "
371 "Cannot access! This is probably a bug in the "
372 "driver.", (unsigned long long)vcn,
373 dir_ni->mft_no);
374 goto unm_err_out;
375 }
376 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
377 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
378 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
379 "inode 0x%lx exceeds maximum size.",
380 (unsigned long long)vcn, dir_ni->mft_no);
381 goto unm_err_out;
382 }
383 /* The first index entry. */
384 ie = (INDEX_ENTRY*)((u8*)&ia->index +
385 le32_to_cpu(ia->index.entries_offset));
386 /*
387 * Iterate similar to above big loop but applied to index buffer, thus
388 * loop until we exceed valid memory (corruption case) or until we
389 * reach the last entry.
390 */
391 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
392 /* Bounds check. */
393 if ((u8*)ie < (u8*)ia || (u8*)ie +
394 sizeof(INDEX_ENTRY_HEADER) > index_end ||
395 (u8*)ie + le16_to_cpu(ie->key_length) >
396 index_end) {
397 ntfs_error(sb, "Index entry out of bounds in "
398 "directory inode 0x%lx.",
399 dir_ni->mft_no);
400 goto unm_err_out;
401 }
402 /*
403 * The last entry cannot contain a name. It can however contain
404 * a pointer to a child node in the B+tree so we just break out.
405 */
406 if (ie->flags & INDEX_ENTRY_END)
407 break;
408 /*
409 * We perform a case sensitive comparison and if that matches
410 * we are done and return the mft reference of the inode (i.e.
411 * the inode number together with the sequence number for
412 * consistency checking). We convert it to cpu format before
413 * returning.
414 */
415 if (ntfs_are_names_equal(uname, uname_len,
416 (ntfschar*)&ie->key.file_name.file_name,
417 ie->key.file_name.file_name_length,
418 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
419found_it2:
420 /*
421 * We have a perfect match, so we don't need to care
422 * about having matched imperfectly before, so we can
423 * free name and set *res to NULL.
424 * However, if the perfect match is a short file name,
425 * we need to signal this through *res, so that
426 * ntfs_lookup() can fix dcache aliasing issues.
427 * As an optimization we just reuse an existing
428 * allocation of *res.
429 */
430 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
431 if (!name) {
432 name = kmalloc(sizeof(ntfs_name),
433 GFP_NOFS);
434 if (!name) {
435 err = -ENOMEM;
436 goto unm_err_out;
437 }
438 }
439 name->mref = le64_to_cpu(
440 ie->data.dir.indexed_file);
441 name->type = FILE_NAME_DOS;
442 name->len = 0;
443 *res = name;
444 } else {
Jesper Juhl251c8422005-04-04 14:59:56 +0100445 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 *res = NULL;
447 }
448 mref = le64_to_cpu(ie->data.dir.indexed_file);
449 unlock_page(page);
450 ntfs_unmap_page(page);
451 return mref;
452 }
453 /*
454 * For a case insensitive mount, we also perform a case
455 * insensitive comparison (provided the file name is not in the
456 * POSIX namespace). If the comparison matches, and the name is
457 * in the WIN32 namespace, we cache the filename in *res so
458 * that the caller, ntfs_lookup(), can work on it. If the
459 * comparison matches, and the name is in the DOS namespace, we
460 * only cache the mft reference and the file name type (we set
461 * the name length to zero for simplicity).
462 */
463 if (!NVolCaseSensitive(vol) &&
464 ie->key.file_name.file_name_type &&
465 ntfs_are_names_equal(uname, uname_len,
466 (ntfschar*)&ie->key.file_name.file_name,
467 ie->key.file_name.file_name_length,
468 IGNORE_CASE, vol->upcase, vol->upcase_len)) {
469 int name_size = sizeof(ntfs_name);
470 u8 type = ie->key.file_name.file_name_type;
471 u8 len = ie->key.file_name.file_name_length;
472
473 /* Only one case insensitive matching name allowed. */
474 if (name) {
475 ntfs_error(sb, "Found already allocated name "
476 "in phase 2. Please run chkdsk "
477 "and if that doesn't find any "
478 "errors please report you saw "
479 "this message to "
480 "linux-ntfs-dev@lists."
481 "sourceforge.net.");
482 unlock_page(page);
483 ntfs_unmap_page(page);
484 goto dir_err_out;
485 }
486
487 if (type != FILE_NAME_DOS)
488 name_size += len * sizeof(ntfschar);
489 name = kmalloc(name_size, GFP_NOFS);
490 if (!name) {
491 err = -ENOMEM;
492 goto unm_err_out;
493 }
494 name->mref = le64_to_cpu(ie->data.dir.indexed_file);
495 name->type = type;
496 if (type != FILE_NAME_DOS) {
497 name->len = len;
498 memcpy(name->name, ie->key.file_name.file_name,
499 len * sizeof(ntfschar));
500 } else
501 name->len = 0;
502 *res = name;
503 }
504 /*
505 * Not a perfect match, need to do full blown collation so we
506 * know which way in the B+tree we have to go.
507 */
508 rc = ntfs_collate_names(uname, uname_len,
509 (ntfschar*)&ie->key.file_name.file_name,
510 ie->key.file_name.file_name_length, 1,
511 IGNORE_CASE, vol->upcase, vol->upcase_len);
512 /*
513 * If uname collates before the name of the current entry, there
514 * is definitely no such name in this index but we might need to
515 * descend into the B+tree so we just break out of the loop.
516 */
517 if (rc == -1)
518 break;
519 /* The names are not equal, continue the search. */
520 if (rc)
521 continue;
522 /*
523 * Names match with case insensitive comparison, now try the
524 * case sensitive comparison, which is required for proper
525 * collation.
526 */
527 rc = ntfs_collate_names(uname, uname_len,
528 (ntfschar*)&ie->key.file_name.file_name,
529 ie->key.file_name.file_name_length, 1,
530 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
531 if (rc == -1)
532 break;
533 if (rc)
534 continue;
535 /*
536 * Perfect match, this will never happen as the
537 * ntfs_are_names_equal() call will have gotten a match but we
538 * still treat it correctly.
539 */
540 goto found_it2;
541 }
542 /*
543 * We have finished with this index buffer without success. Check for
544 * the presence of a child node.
545 */
546 if (ie->flags & INDEX_ENTRY_NODE) {
547 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
548 ntfs_error(sb, "Index entry with child node found in "
549 "a leaf node in directory inode 0x%lx.",
550 dir_ni->mft_no);
551 goto unm_err_out;
552 }
553 /* Child node present, descend into it. */
554 old_vcn = vcn;
555 vcn = sle64_to_cpup((sle64*)((u8*)ie +
556 le16_to_cpu(ie->length) - 8));
557 if (vcn >= 0) {
558 /* If vcn is in the same page cache page as old_vcn we
559 * recycle the mapped page. */
560 if (old_vcn << vol->cluster_size_bits >>
561 PAGE_CACHE_SHIFT == vcn <<
562 vol->cluster_size_bits >>
563 PAGE_CACHE_SHIFT)
564 goto fast_descend_into_child_node;
565 unlock_page(page);
566 ntfs_unmap_page(page);
567 goto descend_into_child_node;
568 }
569 ntfs_error(sb, "Negative child node vcn in directory inode "
570 "0x%lx.", dir_ni->mft_no);
571 goto unm_err_out;
572 }
573 /*
574 * No child node present, return -ENOENT, unless we have got a matching
575 * name cached in name in which case return the mft reference
576 * associated with it.
577 */
578 if (name) {
579 unlock_page(page);
580 ntfs_unmap_page(page);
581 return name->mref;
582 }
583 ntfs_debug("Entry not found.");
584 err = -ENOENT;
585unm_err_out:
586 unlock_page(page);
587 ntfs_unmap_page(page);
588err_out:
589 if (!err)
590 err = -EIO;
591 if (ctx)
592 ntfs_attr_put_search_ctx(ctx);
593 if (m)
594 unmap_mft_record(dir_ni);
595 if (name) {
596 kfree(name);
597 *res = NULL;
598 }
599 return ERR_MREF(err);
600dir_err_out:
601 ntfs_error(sb, "Corrupt directory. Aborting lookup.");
602 goto err_out;
603}
604
605#if 0
606
607// TODO: (AIA)
608// The algorithm embedded in this code will be required for the time when we
609// want to support adding of entries to directories, where we require correct
Anton Altaparmakovc002f422005-02-03 12:02:56 +0000610// collation of file names in order not to cause corruption of the filesystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
612/**
613 * ntfs_lookup_inode_by_name - find an inode in a directory given its name
614 * @dir_ni: ntfs inode of the directory in which to search for the name
615 * @uname: Unicode name for which to search in the directory
616 * @uname_len: length of the name @uname in Unicode characters
617 *
618 * Look for an inode with name @uname in the directory with inode @dir_ni.
619 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for
620 * the Unicode name. If the name is found in the directory, the corresponding
621 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
622 * is a 64-bit number containing the sequence number.
623 *
624 * On error, a negative value is returned corresponding to the error code. In
625 * particular if the inode is not found -ENOENT is returned. Note that you
626 * can't just check the return value for being negative, you have to check the
627 * inode number for being negative which you can extract using MREC(return
628 * value).
629 *
630 * Note, @uname_len does not include the (optional) terminating NULL character.
631 */
632u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
633 const int uname_len)
634{
635 ntfs_volume *vol = dir_ni->vol;
636 struct super_block *sb = vol->sb;
637 MFT_RECORD *m;
638 INDEX_ROOT *ir;
639 INDEX_ENTRY *ie;
640 INDEX_ALLOCATION *ia;
641 u8 *index_end;
642 u64 mref;
643 ntfs_attr_search_ctx *ctx;
644 int err, rc;
645 IGNORE_CASE_BOOL ic;
646 VCN vcn, old_vcn;
647 struct address_space *ia_mapping;
648 struct page *page;
649 u8 *kaddr;
650
651 /* Get hold of the mft record for the directory. */
652 m = map_mft_record(dir_ni);
653 if (IS_ERR(m)) {
654 ntfs_error(sb, "map_mft_record() failed with error code %ld.",
655 -PTR_ERR(m));
656 return ERR_MREF(PTR_ERR(m));
657 }
658 ctx = ntfs_attr_get_search_ctx(dir_ni, m);
659 if (!ctx) {
660 err = -ENOMEM;
661 goto err_out;
662 }
663 /* Find the index root attribute in the mft record. */
664 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
665 0, ctx);
666 if (unlikely(err)) {
667 if (err == -ENOENT) {
668 ntfs_error(sb, "Index root attribute missing in "
669 "directory inode 0x%lx.",
670 dir_ni->mft_no);
671 err = -EIO;
672 }
673 goto err_out;
674 }
675 /* Get to the index root value (it's been verified in read_inode). */
676 ir = (INDEX_ROOT*)((u8*)ctx->attr +
677 le16_to_cpu(ctx->attr->data.resident.value_offset));
678 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
679 /* The first index entry. */
680 ie = (INDEX_ENTRY*)((u8*)&ir->index +
681 le32_to_cpu(ir->index.entries_offset));
682 /*
683 * Loop until we exceed valid memory (corruption case) or until we
684 * reach the last entry.
685 */
686 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
687 /* Bounds checks. */
688 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie +
689 sizeof(INDEX_ENTRY_HEADER) > index_end ||
690 (u8*)ie + le16_to_cpu(ie->key_length) >
691 index_end)
692 goto dir_err_out;
693 /*
694 * The last entry cannot contain a name. It can however contain
695 * a pointer to a child node in the B+tree so we just break out.
696 */
697 if (ie->flags & INDEX_ENTRY_END)
698 break;
699 /*
700 * If the current entry has a name type of POSIX, the name is
701 * case sensitive and not otherwise. This has the effect of us
702 * not being able to access any POSIX file names which collate
703 * after the non-POSIX one when they only differ in case, but
704 * anyone doing screwy stuff like that deserves to burn in
705 * hell... Doing that kind of stuff on NT4 actually causes
706 * corruption on the partition even when using SP6a and Linux
707 * is not involved at all.
708 */
709 ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
710 CASE_SENSITIVE;
711 /*
712 * If the names match perfectly, we are done and return the
713 * mft reference of the inode (i.e. the inode number together
714 * with the sequence number for consistency checking. We
715 * convert it to cpu format before returning.
716 */
717 if (ntfs_are_names_equal(uname, uname_len,
718 (ntfschar*)&ie->key.file_name.file_name,
719 ie->key.file_name.file_name_length, ic,
720 vol->upcase, vol->upcase_len)) {
721found_it:
722 mref = le64_to_cpu(ie->data.dir.indexed_file);
723 ntfs_attr_put_search_ctx(ctx);
724 unmap_mft_record(dir_ni);
725 return mref;
726 }
727 /*
728 * Not a perfect match, need to do full blown collation so we
729 * know which way in the B+tree we have to go.
730 */
731 rc = ntfs_collate_names(uname, uname_len,
732 (ntfschar*)&ie->key.file_name.file_name,
733 ie->key.file_name.file_name_length, 1,
734 IGNORE_CASE, vol->upcase, vol->upcase_len);
735 /*
736 * If uname collates before the name of the current entry, there
737 * is definitely no such name in this index but we might need to
738 * descend into the B+tree so we just break out of the loop.
739 */
740 if (rc == -1)
741 break;
742 /* The names are not equal, continue the search. */
743 if (rc)
744 continue;
745 /*
746 * Names match with case insensitive comparison, now try the
747 * case sensitive comparison, which is required for proper
748 * collation.
749 */
750 rc = ntfs_collate_names(uname, uname_len,
751 (ntfschar*)&ie->key.file_name.file_name,
752 ie->key.file_name.file_name_length, 1,
753 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
754 if (rc == -1)
755 break;
756 if (rc)
757 continue;
758 /*
759 * Perfect match, this will never happen as the
760 * ntfs_are_names_equal() call will have gotten a match but we
761 * still treat it correctly.
762 */
763 goto found_it;
764 }
765 /*
766 * We have finished with this index without success. Check for the
767 * presence of a child node.
768 */
769 if (!(ie->flags & INDEX_ENTRY_NODE)) {
770 /* No child node, return -ENOENT. */
771 err = -ENOENT;
772 goto err_out;
773 } /* Child node present, descend into it. */
774 /* Consistency check: Verify that an index allocation exists. */
775 if (!NInoIndexAllocPresent(dir_ni)) {
776 ntfs_error(sb, "No index allocation attribute but index entry "
777 "requires one. Directory inode 0x%lx is "
778 "corrupt or driver bug.", dir_ni->mft_no);
779 goto err_out;
780 }
781 /* Get the starting vcn of the index_block holding the child node. */
782 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
783 ia_mapping = VFS_I(dir_ni)->i_mapping;
784 /*
785 * We are done with the index root and the mft record. Release them,
786 * otherwise we deadlock with ntfs_map_page().
787 */
788 ntfs_attr_put_search_ctx(ctx);
789 unmap_mft_record(dir_ni);
790 m = NULL;
791 ctx = NULL;
792descend_into_child_node:
793 /*
794 * Convert vcn to index into the index allocation attribute in units
795 * of PAGE_CACHE_SIZE and map the page cache page, reading it from
796 * disk if necessary.
797 */
798 page = ntfs_map_page(ia_mapping, vcn <<
799 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
800 if (IS_ERR(page)) {
801 ntfs_error(sb, "Failed to map directory index page, error %ld.",
802 -PTR_ERR(page));
803 err = PTR_ERR(page);
804 goto err_out;
805 }
806 lock_page(page);
807 kaddr = (u8*)page_address(page);
808fast_descend_into_child_node:
809 /* Get to the index allocation block. */
810 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
811 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
812 /* Bounds checks. */
813 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
814 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
815 "inode 0x%lx or driver bug.", dir_ni->mft_no);
816 goto unm_err_out;
817 }
818 /* Catch multi sector transfer fixup errors. */
819 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
820 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
821 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
822 (unsigned long long)vcn, dir_ni->mft_no);
823 goto unm_err_out;
824 }
825 if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
826 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
827 "different from expected VCN (0x%llx). "
828 "Directory inode 0x%lx is corrupt or driver "
829 "bug.", (unsigned long long)
830 sle64_to_cpu(ia->index_block_vcn),
831 (unsigned long long)vcn, dir_ni->mft_no);
832 goto unm_err_out;
833 }
834 if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
835 dir_ni->itype.index.block_size) {
836 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
837 "0x%lx has a size (%u) differing from the "
838 "directory specified size (%u). Directory "
839 "inode is corrupt or driver bug.",
840 (unsigned long long)vcn, dir_ni->mft_no,
841 le32_to_cpu(ia->index.allocated_size) + 0x18,
842 dir_ni->itype.index.block_size);
843 goto unm_err_out;
844 }
845 index_end = (u8*)ia + dir_ni->itype.index.block_size;
846 if (index_end > kaddr + PAGE_CACHE_SIZE) {
847 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
848 "0x%lx crosses page boundary. Impossible! "
849 "Cannot access! This is probably a bug in the "
850 "driver.", (unsigned long long)vcn,
851 dir_ni->mft_no);
852 goto unm_err_out;
853 }
854 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
855 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
856 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
857 "inode 0x%lx exceeds maximum size.",
858 (unsigned long long)vcn, dir_ni->mft_no);
859 goto unm_err_out;
860 }
861 /* The first index entry. */
862 ie = (INDEX_ENTRY*)((u8*)&ia->index +
863 le32_to_cpu(ia->index.entries_offset));
864 /*
865 * Iterate similar to above big loop but applied to index buffer, thus
866 * loop until we exceed valid memory (corruption case) or until we
867 * reach the last entry.
868 */
869 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
870 /* Bounds check. */
871 if ((u8*)ie < (u8*)ia || (u8*)ie +
872 sizeof(INDEX_ENTRY_HEADER) > index_end ||
873 (u8*)ie + le16_to_cpu(ie->key_length) >
874 index_end) {
875 ntfs_error(sb, "Index entry out of bounds in "
876 "directory inode 0x%lx.",
877 dir_ni->mft_no);
878 goto unm_err_out;
879 }
880 /*
881 * The last entry cannot contain a name. It can however contain
882 * a pointer to a child node in the B+tree so we just break out.
883 */
884 if (ie->flags & INDEX_ENTRY_END)
885 break;
886 /*
887 * If the current entry has a name type of POSIX, the name is
888 * case sensitive and not otherwise. This has the effect of us
889 * not being able to access any POSIX file names which collate
890 * after the non-POSIX one when they only differ in case, but
891 * anyone doing screwy stuff like that deserves to burn in
892 * hell... Doing that kind of stuff on NT4 actually causes
893 * corruption on the partition even when using SP6a and Linux
894 * is not involved at all.
895 */
896 ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
897 CASE_SENSITIVE;
898 /*
899 * If the names match perfectly, we are done and return the
900 * mft reference of the inode (i.e. the inode number together
901 * with the sequence number for consistency checking. We
902 * convert it to cpu format before returning.
903 */
904 if (ntfs_are_names_equal(uname, uname_len,
905 (ntfschar*)&ie->key.file_name.file_name,
906 ie->key.file_name.file_name_length, ic,
907 vol->upcase, vol->upcase_len)) {
908found_it2:
909 mref = le64_to_cpu(ie->data.dir.indexed_file);
910 unlock_page(page);
911 ntfs_unmap_page(page);
912 return mref;
913 }
914 /*
915 * Not a perfect match, need to do full blown collation so we
916 * know which way in the B+tree we have to go.
917 */
918 rc = ntfs_collate_names(uname, uname_len,
919 (ntfschar*)&ie->key.file_name.file_name,
920 ie->key.file_name.file_name_length, 1,
921 IGNORE_CASE, vol->upcase, vol->upcase_len);
922 /*
923 * If uname collates before the name of the current entry, there
924 * is definitely no such name in this index but we might need to
925 * descend into the B+tree so we just break out of the loop.
926 */
927 if (rc == -1)
928 break;
929 /* The names are not equal, continue the search. */
930 if (rc)
931 continue;
932 /*
933 * Names match with case insensitive comparison, now try the
934 * case sensitive comparison, which is required for proper
935 * collation.
936 */
937 rc = ntfs_collate_names(uname, uname_len,
938 (ntfschar*)&ie->key.file_name.file_name,
939 ie->key.file_name.file_name_length, 1,
940 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
941 if (rc == -1)
942 break;
943 if (rc)
944 continue;
945 /*
946 * Perfect match, this will never happen as the
947 * ntfs_are_names_equal() call will have gotten a match but we
948 * still treat it correctly.
949 */
950 goto found_it2;
951 }
952 /*
953 * We have finished with this index buffer without success. Check for
954 * the presence of a child node.
955 */
956 if (ie->flags & INDEX_ENTRY_NODE) {
957 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
958 ntfs_error(sb, "Index entry with child node found in "
959 "a leaf node in directory inode 0x%lx.",
960 dir_ni->mft_no);
961 goto unm_err_out;
962 }
963 /* Child node present, descend into it. */
964 old_vcn = vcn;
965 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
966 if (vcn >= 0) {
967 /* If vcn is in the same page cache page as old_vcn we
968 * recycle the mapped page. */
969 if (old_vcn << vol->cluster_size_bits >>
970 PAGE_CACHE_SHIFT == vcn <<
971 vol->cluster_size_bits >>
972 PAGE_CACHE_SHIFT)
973 goto fast_descend_into_child_node;
974 unlock_page(page);
975 ntfs_unmap_page(page);
976 goto descend_into_child_node;
977 }
978 ntfs_error(sb, "Negative child node vcn in directory inode "
979 "0x%lx.", dir_ni->mft_no);
980 goto unm_err_out;
981 }
982 /* No child node, return -ENOENT. */
983 ntfs_debug("Entry not found.");
984 err = -ENOENT;
985unm_err_out:
986 unlock_page(page);
987 ntfs_unmap_page(page);
988err_out:
989 if (!err)
990 err = -EIO;
991 if (ctx)
992 ntfs_attr_put_search_ctx(ctx);
993 if (m)
994 unmap_mft_record(dir_ni);
995 return ERR_MREF(err);
996dir_err_out:
997 ntfs_error(sb, "Corrupt directory. Aborting lookup.");
998 goto err_out;
999}
1000
1001#endif
1002
1003/**
1004 * ntfs_filldir - ntfs specific filldir method
1005 * @vol: current ntfs volume
1006 * @fpos: position in the directory
1007 * @ndir: ntfs inode of current directory
1008 * @ia_page: page in which the index allocation buffer @ie is in resides
1009 * @ie: current index entry
1010 * @name: buffer to use for the converted name
1011 * @dirent: vfs filldir callback context
1012 * @filldir: vfs filldir callback
1013 *
1014 * Convert the Unicode @name to the loaded NLS and pass it to the @filldir
1015 * callback.
1016 *
1017 * If @ia_page is not NULL it is the locked page containing the index
1018 * allocation block containing the index entry @ie.
1019 *
1020 * Note, we drop (and then reacquire) the page lock on @ia_page across the
1021 * @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup
1022 * since ntfs_lookup() will lock the same page. As an optimization, we do not
1023 * retake the lock if we are returning a non-zero value as ntfs_readdir()
1024 * would need to drop the lock immediately anyway.
1025 */
1026static inline int ntfs_filldir(ntfs_volume *vol, loff_t fpos,
1027 ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie,
1028 u8 *name, void *dirent, filldir_t filldir)
1029{
1030 unsigned long mref;
1031 int name_len, rc;
1032 unsigned dt_type;
1033 FILE_NAME_TYPE_FLAGS name_type;
1034
1035 name_type = ie->key.file_name.file_name_type;
1036 if (name_type == FILE_NAME_DOS) {
1037 ntfs_debug("Skipping DOS name space entry.");
1038 return 0;
1039 }
1040 if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) {
1041 ntfs_debug("Skipping root directory self reference entry.");
1042 return 0;
1043 }
1044 if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user &&
1045 !NVolShowSystemFiles(vol)) {
1046 ntfs_debug("Skipping system file.");
1047 return 0;
1048 }
1049 name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name,
1050 ie->key.file_name.file_name_length, &name,
1051 NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1);
1052 if (name_len <= 0) {
Anton Altaparmakovf94ad382005-09-08 17:04:11 +01001053 ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.",
1054 (long long)MREF_LE(ie->data.dir.indexed_file));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 return 0;
1056 }
1057 if (ie->key.file_name.file_attributes &
1058 FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT)
1059 dt_type = DT_DIR;
1060 else
1061 dt_type = DT_REG;
1062 mref = MREF_LE(ie->data.dir.indexed_file);
1063 /*
1064 * Drop the page lock otherwise we deadlock with NFS when it calls
1065 * ->lookup since ntfs_lookup() will lock the same page.
1066 */
1067 if (ia_page)
1068 unlock_page(ia_page);
1069 ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode "
1070 "0x%lx, DT_%s.", name, name_len, fpos, mref,
1071 dt_type == DT_DIR ? "DIR" : "REG");
1072 rc = filldir(dirent, name, name_len, fpos, mref, dt_type);
1073 /* Relock the page but not if we are aborting ->readdir. */
1074 if (!rc && ia_page)
1075 lock_page(ia_page);
1076 return rc;
1077}
1078
1079/*
1080 * We use the same basic approach as the old NTFS driver, i.e. we parse the
1081 * index root entries and then the index allocation entries that are marked
1082 * as in use in the index bitmap.
1083 *
1084 * While this will return the names in random order this doesn't matter for
1085 * ->readdir but OTOH results in a faster ->readdir.
1086 *
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001087 * VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088 * parts (e.g. ->f_pos and ->i_size, and it also protects against directory
1089 * modifications).
1090 *
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001091 * Locking: - Caller must hold i_mutex on the directory.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 * - Each page cache page in the index allocation mapping must be
1093 * locked whilst being accessed otherwise we may find a corrupt
1094 * page due to it being under ->writepage at the moment which
1095 * applies the mst protection fixups before writing out and then
1096 * removes them again after the write is complete after which it
1097 * unlocks the page.
1098 */
1099static int ntfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1100{
1101 s64 ia_pos, ia_start, prev_ia_pos, bmp_pos;
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001102 loff_t fpos, i_size;
Josef "Jeff" Sipek20d29372006-12-08 02:36:41 -08001103 struct inode *bmp_vi, *vdir = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 struct super_block *sb = vdir->i_sb;
1105 ntfs_inode *ndir = NTFS_I(vdir);
1106 ntfs_volume *vol = NTFS_SB(sb);
1107 MFT_RECORD *m;
1108 INDEX_ROOT *ir = NULL;
1109 INDEX_ENTRY *ie;
1110 INDEX_ALLOCATION *ia;
1111 u8 *name = NULL;
1112 int rc, err, ir_pos, cur_bmp_pos;
1113 struct address_space *ia_mapping, *bmp_mapping;
1114 struct page *bmp_page = NULL, *ia_page = NULL;
1115 u8 *kaddr, *bmp, *index_end;
1116 ntfs_attr_search_ctx *ctx;
1117
1118 fpos = filp->f_pos;
1119 ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.",
1120 vdir->i_ino, fpos);
1121 rc = err = 0;
1122 /* Are we at end of dir yet? */
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001123 i_size = i_size_read(vdir);
1124 if (fpos >= i_size + vol->mft_record_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 goto done;
1126 /* Emulate . and .. for all directories. */
1127 if (!fpos) {
1128 ntfs_debug("Calling filldir for . with len 1, fpos 0x0, "
1129 "inode 0x%lx, DT_DIR.", vdir->i_ino);
1130 rc = filldir(dirent, ".", 1, fpos, vdir->i_ino, DT_DIR);
1131 if (rc)
1132 goto done;
1133 fpos++;
1134 }
1135 if (fpos == 1) {
1136 ntfs_debug("Calling filldir for .. with len 2, fpos 0x1, "
1137 "inode 0x%lx, DT_DIR.",
Josef "Jeff" Sipek20d29372006-12-08 02:36:41 -08001138 (unsigned long)parent_ino(filp->f_path.dentry));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 rc = filldir(dirent, "..", 2, fpos,
Josef "Jeff" Sipek20d29372006-12-08 02:36:41 -08001140 parent_ino(filp->f_path.dentry), DT_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 if (rc)
1142 goto done;
1143 fpos++;
1144 }
1145 m = NULL;
1146 ctx = NULL;
1147 /*
1148 * Allocate a buffer to store the current name being processed
1149 * converted to format determined by current NLS.
1150 */
Panagiotis Issarisf52720c2006-09-27 01:49:39 -07001151 name = kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 if (unlikely(!name)) {
1153 err = -ENOMEM;
1154 goto err_out;
1155 }
1156 /* Are we jumping straight into the index allocation attribute? */
1157 if (fpos >= vol->mft_record_size)
1158 goto skip_index_root;
1159 /* Get hold of the mft record for the directory. */
1160 m = map_mft_record(ndir);
1161 if (IS_ERR(m)) {
1162 err = PTR_ERR(m);
1163 m = NULL;
1164 goto err_out;
1165 }
1166 ctx = ntfs_attr_get_search_ctx(ndir, m);
1167 if (unlikely(!ctx)) {
1168 err = -ENOMEM;
1169 goto err_out;
1170 }
1171 /* Get the offset into the index root attribute. */
1172 ir_pos = (s64)fpos;
1173 /* Find the index root attribute in the mft record. */
1174 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
1175 0, ctx);
1176 if (unlikely(err)) {
1177 ntfs_error(sb, "Index root attribute missing in directory "
1178 "inode 0x%lx.", vdir->i_ino);
1179 goto err_out;
1180 }
1181 /*
1182 * Copy the index root attribute value to a buffer so that we can put
1183 * the search context and unmap the mft record before calling the
1184 * filldir() callback. We need to do this because of NFSd which calls
1185 * ->lookup() from its filldir callback() and this causes NTFS to
1186 * deadlock as ntfs_lookup() maps the mft record of the directory and
1187 * we have got it mapped here already. The only solution is for us to
1188 * unmap the mft record here so that a call to ntfs_lookup() is able to
1189 * map the mft record without deadlocking.
1190 */
1191 rc = le32_to_cpu(ctx->attr->data.resident.value_length);
Panagiotis Issarisf52720c2006-09-27 01:49:39 -07001192 ir = kmalloc(rc, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 if (unlikely(!ir)) {
1194 err = -ENOMEM;
1195 goto err_out;
1196 }
1197 /* Copy the index root value (it has been verified in read_inode). */
1198 memcpy(ir, (u8*)ctx->attr +
1199 le16_to_cpu(ctx->attr->data.resident.value_offset), rc);
1200 ntfs_attr_put_search_ctx(ctx);
1201 unmap_mft_record(ndir);
1202 ctx = NULL;
1203 m = NULL;
1204 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
1205 /* The first index entry. */
1206 ie = (INDEX_ENTRY*)((u8*)&ir->index +
1207 le32_to_cpu(ir->index.entries_offset));
1208 /*
1209 * Loop until we exceed valid memory (corruption case) or until we
1210 * reach the last entry or until filldir tells us it has had enough
1211 * or signals an error (both covered by the rc test).
1212 */
1213 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
1214 ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir);
1215 /* Bounds checks. */
1216 if (unlikely((u8*)ie < (u8*)ir || (u8*)ie +
1217 sizeof(INDEX_ENTRY_HEADER) > index_end ||
1218 (u8*)ie + le16_to_cpu(ie->key_length) >
1219 index_end))
1220 goto err_out;
1221 /* The last entry cannot contain a name. */
1222 if (ie->flags & INDEX_ENTRY_END)
1223 break;
1224 /* Skip index root entry if continuing previous readdir. */
1225 if (ir_pos > (u8*)ie - (u8*)ir)
1226 continue;
1227 /* Advance the position even if going to skip the entry. */
1228 fpos = (u8*)ie - (u8*)ir;
1229 /* Submit the name to the filldir callback. */
1230 rc = ntfs_filldir(vol, fpos, ndir, NULL, ie, name, dirent,
1231 filldir);
1232 if (rc) {
1233 kfree(ir);
1234 goto abort;
1235 }
1236 }
1237 /* We are done with the index root and can free the buffer. */
1238 kfree(ir);
1239 ir = NULL;
1240 /* If there is no index allocation attribute we are finished. */
1241 if (!NInoIndexAllocPresent(ndir))
1242 goto EOD;
1243 /* Advance fpos to the beginning of the index allocation. */
1244 fpos = vol->mft_record_size;
1245skip_index_root:
1246 kaddr = NULL;
1247 prev_ia_pos = -1LL;
1248 /* Get the offset into the index allocation attribute. */
1249 ia_pos = (s64)fpos - vol->mft_record_size;
1250 ia_mapping = vdir->i_mapping;
Anton Altaparmakov83311912007-01-18 09:42:48 +00001251 ntfs_debug("Inode 0x%lx, getting index bitmap.", vdir->i_ino);
1252 bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4);
1253 if (IS_ERR(bmp_vi)) {
1254 ntfs_error(sb, "Failed to get bitmap attribute.");
1255 err = PTR_ERR(bmp_vi);
1256 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 }
1258 bmp_mapping = bmp_vi->i_mapping;
1259 /* Get the starting bitmap bit position and sanity check it. */
1260 bmp_pos = ia_pos >> ndir->itype.index.block_size_bits;
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001261 if (unlikely(bmp_pos >> 3 >= i_size_read(bmp_vi))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 ntfs_error(sb, "Current index allocation position exceeds "
1263 "index bitmap size.");
Anton Altaparmakov83311912007-01-18 09:42:48 +00001264 goto iput_err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 }
1266 /* Get the starting bit position in the current bitmap page. */
1267 cur_bmp_pos = bmp_pos & ((PAGE_CACHE_SIZE * 8) - 1);
1268 bmp_pos &= ~(u64)((PAGE_CACHE_SIZE * 8) - 1);
1269get_next_bmp_page:
1270 ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx",
1271 (unsigned long long)bmp_pos >> (3 + PAGE_CACHE_SHIFT),
1272 (unsigned long long)bmp_pos &
1273 (unsigned long long)((PAGE_CACHE_SIZE * 8) - 1));
1274 bmp_page = ntfs_map_page(bmp_mapping,
1275 bmp_pos >> (3 + PAGE_CACHE_SHIFT));
1276 if (IS_ERR(bmp_page)) {
1277 ntfs_error(sb, "Reading index bitmap failed.");
1278 err = PTR_ERR(bmp_page);
1279 bmp_page = NULL;
Anton Altaparmakov83311912007-01-18 09:42:48 +00001280 goto iput_err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 }
1282 bmp = (u8*)page_address(bmp_page);
1283 /* Find next index block in use. */
1284 while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) {
1285find_next_index_buffer:
1286 cur_bmp_pos++;
1287 /*
1288 * If we have reached the end of the bitmap page, get the next
1289 * page, and put away the old one.
1290 */
1291 if (unlikely((cur_bmp_pos >> 3) >= PAGE_CACHE_SIZE)) {
1292 ntfs_unmap_page(bmp_page);
1293 bmp_pos += PAGE_CACHE_SIZE * 8;
1294 cur_bmp_pos = 0;
1295 goto get_next_bmp_page;
1296 }
1297 /* If we have reached the end of the bitmap, we are done. */
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001298 if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= i_size))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 goto unm_EOD;
1300 ia_pos = (bmp_pos + cur_bmp_pos) <<
1301 ndir->itype.index.block_size_bits;
1302 }
1303 ntfs_debug("Handling index buffer 0x%llx.",
1304 (unsigned long long)bmp_pos + cur_bmp_pos);
1305 /* If the current index buffer is in the same page we reuse the page. */
Anton Altaparmakov3bd1f4a2005-06-25 16:51:58 +01001306 if ((prev_ia_pos & (s64)PAGE_CACHE_MASK) !=
1307 (ia_pos & (s64)PAGE_CACHE_MASK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 prev_ia_pos = ia_pos;
1309 if (likely(ia_page != NULL)) {
1310 unlock_page(ia_page);
1311 ntfs_unmap_page(ia_page);
1312 }
1313 /*
1314 * Map the page cache page containing the current ia_pos,
1315 * reading it from disk if necessary.
1316 */
1317 ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_CACHE_SHIFT);
1318 if (IS_ERR(ia_page)) {
1319 ntfs_error(sb, "Reading index allocation data failed.");
1320 err = PTR_ERR(ia_page);
1321 ia_page = NULL;
1322 goto err_out;
1323 }
1324 lock_page(ia_page);
1325 kaddr = (u8*)page_address(ia_page);
1326 }
1327 /* Get the current index buffer. */
1328 ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_CACHE_MASK &
1329 ~(s64)(ndir->itype.index.block_size - 1)));
1330 /* Bounds checks. */
1331 if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE)) {
1332 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
1333 "inode 0x%lx or driver bug.", vdir->i_ino);
1334 goto err_out;
1335 }
1336 /* Catch multi sector transfer fixup errors. */
1337 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
1338 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
1339 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
1340 (unsigned long long)ia_pos >>
1341 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1342 goto err_out;
1343 }
1344 if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos &
1345 ~(s64)(ndir->itype.index.block_size - 1)) >>
1346 ndir->itype.index.vcn_size_bits)) {
1347 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
1348 "different from expected VCN (0x%llx). "
1349 "Directory inode 0x%lx is corrupt or driver "
1350 "bug. ", (unsigned long long)
1351 sle64_to_cpu(ia->index_block_vcn),
1352 (unsigned long long)ia_pos >>
1353 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1354 goto err_out;
1355 }
1356 if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 !=
1357 ndir->itype.index.block_size)) {
1358 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
1359 "0x%lx has a size (%u) differing from the "
1360 "directory specified size (%u). Directory "
1361 "inode is corrupt or driver bug.",
1362 (unsigned long long)ia_pos >>
1363 ndir->itype.index.vcn_size_bits, vdir->i_ino,
1364 le32_to_cpu(ia->index.allocated_size) + 0x18,
1365 ndir->itype.index.block_size);
1366 goto err_out;
1367 }
1368 index_end = (u8*)ia + ndir->itype.index.block_size;
1369 if (unlikely(index_end > kaddr + PAGE_CACHE_SIZE)) {
1370 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
1371 "0x%lx crosses page boundary. Impossible! "
1372 "Cannot access! This is probably a bug in the "
1373 "driver.", (unsigned long long)ia_pos >>
1374 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1375 goto err_out;
1376 }
1377 ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1);
1378 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
1379 if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) {
1380 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
1381 "inode 0x%lx exceeds maximum size.",
1382 (unsigned long long)ia_pos >>
1383 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1384 goto err_out;
1385 }
1386 /* The first index entry in this index buffer. */
1387 ie = (INDEX_ENTRY*)((u8*)&ia->index +
1388 le32_to_cpu(ia->index.entries_offset));
1389 /*
1390 * Loop until we exceed valid memory (corruption case) or until we
1391 * reach the last entry or until filldir tells us it has had enough
1392 * or signals an error (both covered by the rc test).
1393 */
1394 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
1395 ntfs_debug("In index allocation, offset 0x%llx.",
1396 (unsigned long long)ia_start +
1397 (unsigned long long)((u8*)ie - (u8*)ia));
1398 /* Bounds checks. */
1399 if (unlikely((u8*)ie < (u8*)ia || (u8*)ie +
1400 sizeof(INDEX_ENTRY_HEADER) > index_end ||
1401 (u8*)ie + le16_to_cpu(ie->key_length) >
1402 index_end))
1403 goto err_out;
1404 /* The last entry cannot contain a name. */
1405 if (ie->flags & INDEX_ENTRY_END)
1406 break;
1407 /* Skip index block entry if continuing previous readdir. */
1408 if (ia_pos - ia_start > (u8*)ie - (u8*)ia)
1409 continue;
1410 /* Advance the position even if going to skip the entry. */
1411 fpos = (u8*)ie - (u8*)ia +
1412 (sle64_to_cpu(ia->index_block_vcn) <<
1413 ndir->itype.index.vcn_size_bits) +
1414 vol->mft_record_size;
1415 /*
1416 * Submit the name to the @filldir callback. Note,
1417 * ntfs_filldir() drops the lock on @ia_page but it retakes it
1418 * before returning, unless a non-zero value is returned in
1419 * which case the page is left unlocked.
1420 */
1421 rc = ntfs_filldir(vol, fpos, ndir, ia_page, ie, name, dirent,
1422 filldir);
1423 if (rc) {
1424 /* @ia_page is already unlocked in this case. */
1425 ntfs_unmap_page(ia_page);
1426 ntfs_unmap_page(bmp_page);
Anton Altaparmakov83311912007-01-18 09:42:48 +00001427 iput(bmp_vi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 goto abort;
1429 }
1430 }
1431 goto find_next_index_buffer;
1432unm_EOD:
1433 if (ia_page) {
1434 unlock_page(ia_page);
1435 ntfs_unmap_page(ia_page);
1436 }
1437 ntfs_unmap_page(bmp_page);
Anton Altaparmakov83311912007-01-18 09:42:48 +00001438 iput(bmp_vi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439EOD:
1440 /* We are finished, set fpos to EOD. */
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001441 fpos = i_size + vol->mft_record_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442abort:
1443 kfree(name);
1444done:
1445#ifdef DEBUG
1446 if (!rc)
1447 ntfs_debug("EOD, fpos 0x%llx, returning 0.", fpos);
1448 else
1449 ntfs_debug("filldir returned %i, fpos 0x%llx, returning 0.",
1450 rc, fpos);
1451#endif
1452 filp->f_pos = fpos;
1453 return 0;
1454err_out:
Anton Altaparmakov83311912007-01-18 09:42:48 +00001455 if (bmp_page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456 ntfs_unmap_page(bmp_page);
Anton Altaparmakov83311912007-01-18 09:42:48 +00001457iput_err_out:
1458 iput(bmp_vi);
1459 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460 if (ia_page) {
1461 unlock_page(ia_page);
1462 ntfs_unmap_page(ia_page);
1463 }
Jesper Juhl251c8422005-04-04 14:59:56 +01001464 kfree(ir);
1465 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466 if (ctx)
1467 ntfs_attr_put_search_ctx(ctx);
1468 if (m)
1469 unmap_mft_record(ndir);
1470 if (!err)
1471 err = -EIO;
1472 ntfs_debug("Failed. Returning error code %i.", -err);
1473 filp->f_pos = fpos;
1474 return err;
1475}
1476
1477/**
1478 * ntfs_dir_open - called when an inode is about to be opened
1479 * @vi: inode to be opened
1480 * @filp: file structure describing the inode
1481 *
1482 * Limit directory size to the page cache limit on architectures where unsigned
1483 * long is 32-bits. This is the most we can do for now without overflowing the
1484 * page cache page index. Doing it this way means we don't run into problems
1485 * because of existing too large directories. It would be better to allow the
1486 * user to read the accessible part of the directory but I doubt very much
1487 * anyone is going to hit this check on a 32-bit architecture, so there is no
1488 * point in adding the extra complexity required to support this.
1489 *
1490 * On 64-bit architectures, the check is hopefully optimized away by the
1491 * compiler.
1492 */
1493static int ntfs_dir_open(struct inode *vi, struct file *filp)
1494{
1495 if (sizeof(unsigned long) < 8) {
Anton Altaparmakov206f9f32004-11-18 15:01:06 +00001496 if (i_size_read(vi) > MAX_LFS_FILESIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497 return -EFBIG;
1498 }
1499 return 0;
1500}
1501
1502#ifdef NTFS_RW
1503
1504/**
1505 * ntfs_dir_fsync - sync a directory to disk
1506 * @filp: directory to be synced
1507 * @dentry: dentry describing the directory to sync
1508 * @datasync: if non-zero only flush user data and not metadata
1509 *
1510 * Data integrity sync of a directory to disk. Used for fsync, fdatasync, and
1511 * msync system calls. This function is based on file.c::ntfs_file_fsync().
1512 *
1513 * Write the mft record and all associated extent mft records as well as the
1514 * $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device.
1515 *
1516 * If @datasync is true, we do not wait on the inode(s) to be written out
1517 * but we always wait on the page cache pages to be written out.
1518 *
1519 * Note: In the past @filp could be NULL so we ignore it as we don't need it
1520 * anyway.
1521 *
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001522 * Locking: Caller must hold i_mutex on the inode.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 *
1524 * TODO: We should probably also write all attribute/index inodes associated
1525 * with this inode but since we have no simple way of getting to them we ignore
1526 * this problem for now. We do write the $BITMAP attribute if it is present
1527 * which is the important one for a directory so things are not too bad.
1528 */
1529static int ntfs_dir_fsync(struct file *filp, struct dentry *dentry,
1530 int datasync)
1531{
Anton Altaparmakov83311912007-01-18 09:42:48 +00001532 struct inode *bmp_vi, *vi = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 int err, ret;
Anton Altaparmakov83311912007-01-18 09:42:48 +00001534 ntfs_attr na;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535
1536 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1537 BUG_ON(!S_ISDIR(vi->i_mode));
Anton Altaparmakov83311912007-01-18 09:42:48 +00001538 /* If the bitmap attribute inode is in memory sync it, too. */
1539 na.mft_no = vi->i_ino;
1540 na.type = AT_BITMAP;
1541 na.name = I30;
1542 na.name_len = 4;
1543 bmp_vi = ilookup5(vi->i_sb, vi->i_ino, (test_t)ntfs_test_inode, &na);
1544 if (bmp_vi) {
1545 write_inode_now(bmp_vi, !datasync);
1546 iput(bmp_vi);
1547 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 ret = ntfs_write_inode(vi, 1);
1549 write_inode_now(vi, !datasync);
1550 err = sync_blockdev(vi->i_sb->s_bdev);
1551 if (unlikely(err && !ret))
1552 ret = err;
1553 if (likely(!ret))
1554 ntfs_debug("Done.");
1555 else
1556 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
1557 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
1558 return ret;
1559}
1560
1561#endif /* NTFS_RW */
1562
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -08001563const struct file_operations ntfs_dir_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 .llseek = generic_file_llseek, /* Seek inside directory. */
1565 .read = generic_read_dir, /* Return -EISDIR. */
1566 .readdir = ntfs_readdir, /* Read directory contents. */
1567#ifdef NTFS_RW
1568 .fsync = ntfs_dir_fsync, /* Sync a directory to disk. */
1569 /*.aio_fsync = ,*/ /* Sync all outstanding async
1570 i/o operations on a kiocb. */
1571#endif /* NTFS_RW */
1572 /*.ioctl = ,*/ /* Perform function on the
1573 mounted filesystem. */
1574 .open = ntfs_dir_open, /* Open directory. */
1575};