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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/dir.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/ntfs/dir.c')
-rw-r--r--fs/ntfs/dir.c1569
1 files changed, 1569 insertions, 0 deletions
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
new file mode 100644
index 000000000000..93577561cdbe
--- /dev/null
+++ b/fs/ntfs/dir.c
@@ -0,0 +1,1569 @@
1/**
2 * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2001-2004 Anton Altaparmakov
5 * 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
23#include <linux/smp_lock.h>
24#include <linux/buffer_head.h>
25
26#include "dir.h"
27#include "aops.h"
28#include "attrib.h"
29#include "mft.h"
30#include "debug.h"
31#include "ntfs.h"
32
33/**
34 * The little endian Unicode string $I30 as a global constant.
35 */
36ntfschar I30[5] = { const_cpu_to_le16('$'), const_cpu_to_le16('I'),
37 const_cpu_to_le16('3'), const_cpu_to_le16('0'), 0 };
38
39/**
40 * ntfs_lookup_inode_by_name - find an inode in a directory given its name
41 * @dir_ni: ntfs inode of the directory in which to search for the name
42 * @uname: Unicode name for which to search in the directory
43 * @uname_len: length of the name @uname in Unicode characters
44 * @res: return the found file name if necessary (see below)
45 *
46 * Look for an inode with name @uname in the directory with inode @dir_ni.
47 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for
48 * the Unicode name. If the name is found in the directory, the corresponding
49 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
50 * is a 64-bit number containing the sequence number.
51 *
52 * On error, a negative value is returned corresponding to the error code. In
53 * particular if the inode is not found -ENOENT is returned. Note that you
54 * can't just check the return value for being negative, you have to check the
55 * inode number for being negative which you can extract using MREC(return
56 * value).
57 *
58 * Note, @uname_len does not include the (optional) terminating NULL character.
59 *
60 * Note, we look for a case sensitive match first but we also look for a case
61 * insensitive match at the same time. If we find a case insensitive match, we
62 * save that for the case that we don't find an exact match, where we return
63 * the case insensitive match and setup @res (which we allocate!) with the mft
64 * reference, the file name type, length and with a copy of the little endian
65 * Unicode file name itself. If we match a file name which is in the DOS name
66 * space, we only return the mft reference and file name type in @res.
67 * ntfs_lookup() then uses this to find the long file name in the inode itself.
68 * This is to avoid polluting the dcache with short file names. We want them to
69 * work but we don't care for how quickly one can access them. This also fixes
70 * the dcache aliasing issues.
71 *
72 * Locking: - Caller must hold i_sem on the directory.
73 * - Each page cache page in the index allocation mapping must be
74 * locked whilst being accessed otherwise we may find a corrupt
75 * page due to it being under ->writepage at the moment which
76 * applies the mst protection fixups before writing out and then
77 * removes them again after the write is complete after which it
78 * unlocks the page.
79 */
80MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
81 const int uname_len, ntfs_name **res)
82{
83 ntfs_volume *vol = dir_ni->vol;
84 struct super_block *sb = vol->sb;
85 MFT_RECORD *m;
86 INDEX_ROOT *ir;
87 INDEX_ENTRY *ie;
88 INDEX_ALLOCATION *ia;
89 u8 *index_end;
90 u64 mref;
91 ntfs_attr_search_ctx *ctx;
92 int err, rc;
93 VCN vcn, old_vcn;
94 struct address_space *ia_mapping;
95 struct page *page;
96 u8 *kaddr;
97 ntfs_name *name = NULL;
98
99 BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode));
100 BUG_ON(NInoAttr(dir_ni));
101 /* Get hold of the mft record for the directory. */
102 m = map_mft_record(dir_ni);
103 if (IS_ERR(m)) {
104 ntfs_error(sb, "map_mft_record() failed with error code %ld.",
105 -PTR_ERR(m));
106 return ERR_MREF(PTR_ERR(m));
107 }
108 ctx = ntfs_attr_get_search_ctx(dir_ni, m);
109 if (unlikely(!ctx)) {
110 err = -ENOMEM;
111 goto err_out;
112 }
113 /* Find the index root attribute in the mft record. */
114 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
115 0, ctx);
116 if (unlikely(err)) {
117 if (err == -ENOENT) {
118 ntfs_error(sb, "Index root attribute missing in "
119 "directory inode 0x%lx.",
120 dir_ni->mft_no);
121 err = -EIO;
122 }
123 goto err_out;
124 }
125 /* Get to the index root value (it's been verified in read_inode). */
126 ir = (INDEX_ROOT*)((u8*)ctx->attr +
127 le16_to_cpu(ctx->attr->data.resident.value_offset));
128 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
129 /* The first index entry. */
130 ie = (INDEX_ENTRY*)((u8*)&ir->index +
131 le32_to_cpu(ir->index.entries_offset));
132 /*
133 * Loop until we exceed valid memory (corruption case) or until we
134 * reach the last entry.
135 */
136 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
137 /* Bounds checks. */
138 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie +
139 sizeof(INDEX_ENTRY_HEADER) > index_end ||
140 (u8*)ie + le16_to_cpu(ie->key_length) >
141 index_end)
142 goto dir_err_out;
143 /*
144 * The last entry cannot contain a name. It can however contain
145 * a pointer to a child node in the B+tree so we just break out.
146 */
147 if (ie->flags & INDEX_ENTRY_END)
148 break;
149 /*
150 * We perform a case sensitive comparison and if that matches
151 * we are done and return the mft reference of the inode (i.e.
152 * the inode number together with the sequence number for
153 * consistency checking). We convert it to cpu format before
154 * returning.
155 */
156 if (ntfs_are_names_equal(uname, uname_len,
157 (ntfschar*)&ie->key.file_name.file_name,
158 ie->key.file_name.file_name_length,
159 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
160found_it:
161 /*
162 * We have a perfect match, so we don't need to care
163 * about having matched imperfectly before, so we can
164 * free name and set *res to NULL.
165 * However, if the perfect match is a short file name,
166 * we need to signal this through *res, so that
167 * ntfs_lookup() can fix dcache aliasing issues.
168 * As an optimization we just reuse an existing
169 * allocation of *res.
170 */
171 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
172 if (!name) {
173 name = kmalloc(sizeof(ntfs_name),
174 GFP_NOFS);
175 if (!name) {
176 err = -ENOMEM;
177 goto err_out;
178 }
179 }
180 name->mref = le64_to_cpu(
181 ie->data.dir.indexed_file);
182 name->type = FILE_NAME_DOS;
183 name->len = 0;
184 *res = name;
185 } else {
186 if (name)
187 kfree(name);
188 *res = NULL;
189 }
190 mref = le64_to_cpu(ie->data.dir.indexed_file);
191 ntfs_attr_put_search_ctx(ctx);
192 unmap_mft_record(dir_ni);
193 return mref;
194 }
195 /*
196 * For a case insensitive mount, we also perform a case
197 * insensitive comparison (provided the file name is not in the
198 * POSIX namespace). If the comparison matches, and the name is
199 * in the WIN32 namespace, we cache the filename in *res so
200 * that the caller, ntfs_lookup(), can work on it. If the
201 * comparison matches, and the name is in the DOS namespace, we
202 * only cache the mft reference and the file name type (we set
203 * the name length to zero for simplicity).
204 */
205 if (!NVolCaseSensitive(vol) &&
206 ie->key.file_name.file_name_type &&
207 ntfs_are_names_equal(uname, uname_len,
208 (ntfschar*)&ie->key.file_name.file_name,
209 ie->key.file_name.file_name_length,
210 IGNORE_CASE, vol->upcase, vol->upcase_len)) {
211 int name_size = sizeof(ntfs_name);
212 u8 type = ie->key.file_name.file_name_type;
213 u8 len = ie->key.file_name.file_name_length;
214
215 /* Only one case insensitive matching name allowed. */
216 if (name) {
217 ntfs_error(sb, "Found already allocated name "
218 "in phase 1. Please run chkdsk "
219 "and if that doesn't find any "
220 "errors please report you saw "
221 "this message to "
222 "linux-ntfs-dev@lists."
223 "sourceforge.net.");
224 goto dir_err_out;
225 }
226
227 if (type != FILE_NAME_DOS)
228 name_size += len * sizeof(ntfschar);
229 name = kmalloc(name_size, GFP_NOFS);
230 if (!name) {
231 err = -ENOMEM;
232 goto err_out;
233 }
234 name->mref = le64_to_cpu(ie->data.dir.indexed_file);
235 name->type = type;
236 if (type != FILE_NAME_DOS) {
237 name->len = len;
238 memcpy(name->name, ie->key.file_name.file_name,
239 len * sizeof(ntfschar));
240 } else
241 name->len = 0;
242 *res = name;
243 }
244 /*
245 * Not a perfect match, need to do full blown collation so we
246 * know which way in the B+tree we have to go.
247 */
248 rc = ntfs_collate_names(uname, uname_len,
249 (ntfschar*)&ie->key.file_name.file_name,
250 ie->key.file_name.file_name_length, 1,
251 IGNORE_CASE, vol->upcase, vol->upcase_len);
252 /*
253 * If uname collates before the name of the current entry, there
254 * is definitely no such name in this index but we might need to
255 * descend into the B+tree so we just break out of the loop.
256 */
257 if (rc == -1)
258 break;
259 /* The names are not equal, continue the search. */
260 if (rc)
261 continue;
262 /*
263 * Names match with case insensitive comparison, now try the
264 * case sensitive comparison, which is required for proper
265 * collation.
266 */
267 rc = ntfs_collate_names(uname, uname_len,
268 (ntfschar*)&ie->key.file_name.file_name,
269 ie->key.file_name.file_name_length, 1,
270 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
271 if (rc == -1)
272 break;
273 if (rc)
274 continue;
275 /*
276 * Perfect match, this will never happen as the
277 * ntfs_are_names_equal() call will have gotten a match but we
278 * still treat it correctly.
279 */
280 goto found_it;
281 }
282 /*
283 * We have finished with this index without success. Check for the
284 * presence of a child node and if not present return -ENOENT, unless
285 * we have got a matching name cached in name in which case return the
286 * mft reference associated with it.
287 */
288 if (!(ie->flags & INDEX_ENTRY_NODE)) {
289 if (name) {
290 ntfs_attr_put_search_ctx(ctx);
291 unmap_mft_record(dir_ni);
292 return name->mref;
293 }
294 ntfs_debug("Entry not found.");
295 err = -ENOENT;
296 goto err_out;
297 } /* Child node present, descend into it. */
298 /* Consistency check: Verify that an index allocation exists. */
299 if (!NInoIndexAllocPresent(dir_ni)) {
300 ntfs_error(sb, "No index allocation attribute but index entry "
301 "requires one. Directory inode 0x%lx is "
302 "corrupt or driver bug.", dir_ni->mft_no);
303 goto err_out;
304 }
305 /* Get the starting vcn of the index_block holding the child node. */
306 vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
307 ia_mapping = VFS_I(dir_ni)->i_mapping;
308 /*
309 * We are done with the index root and the mft record. Release them,
310 * otherwise we deadlock with ntfs_map_page().
311 */
312 ntfs_attr_put_search_ctx(ctx);
313 unmap_mft_record(dir_ni);
314 m = NULL;
315 ctx = NULL;
316descend_into_child_node:
317 /*
318 * Convert vcn to index into the index allocation attribute in units
319 * of PAGE_CACHE_SIZE and map the page cache page, reading it from
320 * disk if necessary.
321 */
322 page = ntfs_map_page(ia_mapping, vcn <<
323 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
324 if (IS_ERR(page)) {
325 ntfs_error(sb, "Failed to map directory index page, error %ld.",
326 -PTR_ERR(page));
327 err = PTR_ERR(page);
328 goto err_out;
329 }
330 lock_page(page);
331 kaddr = (u8*)page_address(page);
332fast_descend_into_child_node:
333 /* Get to the index allocation block. */
334 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
335 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
336 /* Bounds checks. */
337 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
338 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
339 "inode 0x%lx or driver bug.", dir_ni->mft_no);
340 goto unm_err_out;
341 }
342 /* Catch multi sector transfer fixup errors. */
343 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
344 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
345 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
346 (unsigned long long)vcn, dir_ni->mft_no);
347 goto unm_err_out;
348 }
349 if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
350 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
351 "different from expected VCN (0x%llx). "
352 "Directory inode 0x%lx is corrupt or driver "
353 "bug.", (unsigned long long)
354 sle64_to_cpu(ia->index_block_vcn),
355 (unsigned long long)vcn, dir_ni->mft_no);
356 goto unm_err_out;
357 }
358 if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
359 dir_ni->itype.index.block_size) {
360 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
361 "0x%lx has a size (%u) differing from the "
362 "directory specified size (%u). Directory "
363 "inode is corrupt or driver bug.",
364 (unsigned long long)vcn, dir_ni->mft_no,
365 le32_to_cpu(ia->index.allocated_size) + 0x18,
366 dir_ni->itype.index.block_size);
367 goto unm_err_out;
368 }
369 index_end = (u8*)ia + dir_ni->itype.index.block_size;
370 if (index_end > kaddr + PAGE_CACHE_SIZE) {
371 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
372 "0x%lx crosses page boundary. Impossible! "
373 "Cannot access! This is probably a bug in the "
374 "driver.", (unsigned long long)vcn,
375 dir_ni->mft_no);
376 goto unm_err_out;
377 }
378 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
379 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
380 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
381 "inode 0x%lx exceeds maximum size.",
382 (unsigned long long)vcn, dir_ni->mft_no);
383 goto unm_err_out;
384 }
385 /* The first index entry. */
386 ie = (INDEX_ENTRY*)((u8*)&ia->index +
387 le32_to_cpu(ia->index.entries_offset));
388 /*
389 * Iterate similar to above big loop but applied to index buffer, thus
390 * loop until we exceed valid memory (corruption case) or until we
391 * reach the last entry.
392 */
393 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
394 /* Bounds check. */
395 if ((u8*)ie < (u8*)ia || (u8*)ie +
396 sizeof(INDEX_ENTRY_HEADER) > index_end ||
397 (u8*)ie + le16_to_cpu(ie->key_length) >
398 index_end) {
399 ntfs_error(sb, "Index entry out of bounds in "
400 "directory inode 0x%lx.",
401 dir_ni->mft_no);
402 goto unm_err_out;
403 }
404 /*
405 * The last entry cannot contain a name. It can however contain
406 * a pointer to a child node in the B+tree so we just break out.
407 */
408 if (ie->flags & INDEX_ENTRY_END)
409 break;
410 /*
411 * We perform a case sensitive comparison and if that matches
412 * we are done and return the mft reference of the inode (i.e.
413 * the inode number together with the sequence number for
414 * consistency checking). We convert it to cpu format before
415 * returning.
416 */
417 if (ntfs_are_names_equal(uname, uname_len,
418 (ntfschar*)&ie->key.file_name.file_name,
419 ie->key.file_name.file_name_length,
420 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) {
421found_it2:
422 /*
423 * We have a perfect match, so we don't need to care
424 * about having matched imperfectly before, so we can
425 * free name and set *res to NULL.
426 * However, if the perfect match is a short file name,
427 * we need to signal this through *res, so that
428 * ntfs_lookup() can fix dcache aliasing issues.
429 * As an optimization we just reuse an existing
430 * allocation of *res.
431 */
432 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) {
433 if (!name) {
434 name = kmalloc(sizeof(ntfs_name),
435 GFP_NOFS);
436 if (!name) {
437 err = -ENOMEM;
438 goto unm_err_out;
439 }
440 }
441 name->mref = le64_to_cpu(
442 ie->data.dir.indexed_file);
443 name->type = FILE_NAME_DOS;
444 name->len = 0;
445 *res = name;
446 } else {
447 if (name)
448 kfree(name);
449 *res = NULL;
450 }
451 mref = le64_to_cpu(ie->data.dir.indexed_file);
452 unlock_page(page);
453 ntfs_unmap_page(page);
454 return mref;
455 }
456 /*
457 * For a case insensitive mount, we also perform a case
458 * insensitive comparison (provided the file name is not in the
459 * POSIX namespace). If the comparison matches, and the name is
460 * in the WIN32 namespace, we cache the filename in *res so
461 * that the caller, ntfs_lookup(), can work on it. If the
462 * comparison matches, and the name is in the DOS namespace, we
463 * only cache the mft reference and the file name type (we set
464 * the name length to zero for simplicity).
465 */
466 if (!NVolCaseSensitive(vol) &&
467 ie->key.file_name.file_name_type &&
468 ntfs_are_names_equal(uname, uname_len,
469 (ntfschar*)&ie->key.file_name.file_name,
470 ie->key.file_name.file_name_length,
471 IGNORE_CASE, vol->upcase, vol->upcase_len)) {
472 int name_size = sizeof(ntfs_name);
473 u8 type = ie->key.file_name.file_name_type;
474 u8 len = ie->key.file_name.file_name_length;
475
476 /* Only one case insensitive matching name allowed. */
477 if (name) {
478 ntfs_error(sb, "Found already allocated name "
479 "in phase 2. Please run chkdsk "
480 "and if that doesn't find any "
481 "errors please report you saw "
482 "this message to "
483 "linux-ntfs-dev@lists."
484 "sourceforge.net.");
485 unlock_page(page);
486 ntfs_unmap_page(page);
487 goto dir_err_out;
488 }
489
490 if (type != FILE_NAME_DOS)
491 name_size += len * sizeof(ntfschar);
492 name = kmalloc(name_size, GFP_NOFS);
493 if (!name) {
494 err = -ENOMEM;
495 goto unm_err_out;
496 }
497 name->mref = le64_to_cpu(ie->data.dir.indexed_file);
498 name->type = type;
499 if (type != FILE_NAME_DOS) {
500 name->len = len;
501 memcpy(name->name, ie->key.file_name.file_name,
502 len * sizeof(ntfschar));
503 } else
504 name->len = 0;
505 *res = name;
506 }
507 /*
508 * Not a perfect match, need to do full blown collation so we
509 * know which way in the B+tree we have to go.
510 */
511 rc = ntfs_collate_names(uname, uname_len,
512 (ntfschar*)&ie->key.file_name.file_name,
513 ie->key.file_name.file_name_length, 1,
514 IGNORE_CASE, vol->upcase, vol->upcase_len);
515 /*
516 * If uname collates before the name of the current entry, there
517 * is definitely no such name in this index but we might need to
518 * descend into the B+tree so we just break out of the loop.
519 */
520 if (rc == -1)
521 break;
522 /* The names are not equal, continue the search. */
523 if (rc)
524 continue;
525 /*
526 * Names match with case insensitive comparison, now try the
527 * case sensitive comparison, which is required for proper
528 * collation.
529 */
530 rc = ntfs_collate_names(uname, uname_len,
531 (ntfschar*)&ie->key.file_name.file_name,
532 ie->key.file_name.file_name_length, 1,
533 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
534 if (rc == -1)
535 break;
536 if (rc)
537 continue;
538 /*
539 * Perfect match, this will never happen as the
540 * ntfs_are_names_equal() call will have gotten a match but we
541 * still treat it correctly.
542 */
543 goto found_it2;
544 }
545 /*
546 * We have finished with this index buffer without success. Check for
547 * the presence of a child node.
548 */
549 if (ie->flags & INDEX_ENTRY_NODE) {
550 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
551 ntfs_error(sb, "Index entry with child node found in "
552 "a leaf node in directory inode 0x%lx.",
553 dir_ni->mft_no);
554 goto unm_err_out;
555 }
556 /* Child node present, descend into it. */
557 old_vcn = vcn;
558 vcn = sle64_to_cpup((sle64*)((u8*)ie +
559 le16_to_cpu(ie->length) - 8));
560 if (vcn >= 0) {
561 /* If vcn is in the same page cache page as old_vcn we
562 * recycle the mapped page. */
563 if (old_vcn << vol->cluster_size_bits >>
564 PAGE_CACHE_SHIFT == vcn <<
565 vol->cluster_size_bits >>
566 PAGE_CACHE_SHIFT)
567 goto fast_descend_into_child_node;
568 unlock_page(page);
569 ntfs_unmap_page(page);
570 goto descend_into_child_node;
571 }
572 ntfs_error(sb, "Negative child node vcn in directory inode "
573 "0x%lx.", dir_ni->mft_no);
574 goto unm_err_out;
575 }
576 /*
577 * No child node present, return -ENOENT, unless we have got a matching
578 * name cached in name in which case return the mft reference
579 * associated with it.
580 */
581 if (name) {
582 unlock_page(page);
583 ntfs_unmap_page(page);
584 return name->mref;
585 }
586 ntfs_debug("Entry not found.");
587 err = -ENOENT;
588unm_err_out:
589 unlock_page(page);
590 ntfs_unmap_page(page);
591err_out:
592 if (!err)
593 err = -EIO;
594 if (ctx)
595 ntfs_attr_put_search_ctx(ctx);
596 if (m)
597 unmap_mft_record(dir_ni);
598 if (name) {
599 kfree(name);
600 *res = NULL;
601 }
602 return ERR_MREF(err);
603dir_err_out:
604 ntfs_error(sb, "Corrupt directory. Aborting lookup.");
605 goto err_out;
606}
607
608#if 0
609
610// TODO: (AIA)
611// The algorithm embedded in this code will be required for the time when we
612// want to support adding of entries to directories, where we require correct
613// collation of file names in order not to cause corruption of the file system.
614
615/**
616 * ntfs_lookup_inode_by_name - find an inode in a directory given its name
617 * @dir_ni: ntfs inode of the directory in which to search for the name
618 * @uname: Unicode name for which to search in the directory
619 * @uname_len: length of the name @uname in Unicode characters
620 *
621 * Look for an inode with name @uname in the directory with inode @dir_ni.
622 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for
623 * the Unicode name. If the name is found in the directory, the corresponding
624 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it
625 * is a 64-bit number containing the sequence number.
626 *
627 * On error, a negative value is returned corresponding to the error code. In
628 * particular if the inode is not found -ENOENT is returned. Note that you
629 * can't just check the return value for being negative, you have to check the
630 * inode number for being negative which you can extract using MREC(return
631 * value).
632 *
633 * Note, @uname_len does not include the (optional) terminating NULL character.
634 */
635u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname,
636 const int uname_len)
637{
638 ntfs_volume *vol = dir_ni->vol;
639 struct super_block *sb = vol->sb;
640 MFT_RECORD *m;
641 INDEX_ROOT *ir;
642 INDEX_ENTRY *ie;
643 INDEX_ALLOCATION *ia;
644 u8 *index_end;
645 u64 mref;
646 ntfs_attr_search_ctx *ctx;
647 int err, rc;
648 IGNORE_CASE_BOOL ic;
649 VCN vcn, old_vcn;
650 struct address_space *ia_mapping;
651 struct page *page;
652 u8 *kaddr;
653
654 /* Get hold of the mft record for the directory. */
655 m = map_mft_record(dir_ni);
656 if (IS_ERR(m)) {
657 ntfs_error(sb, "map_mft_record() failed with error code %ld.",
658 -PTR_ERR(m));
659 return ERR_MREF(PTR_ERR(m));
660 }
661 ctx = ntfs_attr_get_search_ctx(dir_ni, m);
662 if (!ctx) {
663 err = -ENOMEM;
664 goto err_out;
665 }
666 /* Find the index root attribute in the mft record. */
667 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
668 0, ctx);
669 if (unlikely(err)) {
670 if (err == -ENOENT) {
671 ntfs_error(sb, "Index root attribute missing in "
672 "directory inode 0x%lx.",
673 dir_ni->mft_no);
674 err = -EIO;
675 }
676 goto err_out;
677 }
678 /* Get to the index root value (it's been verified in read_inode). */
679 ir = (INDEX_ROOT*)((u8*)ctx->attr +
680 le16_to_cpu(ctx->attr->data.resident.value_offset));
681 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
682 /* The first index entry. */
683 ie = (INDEX_ENTRY*)((u8*)&ir->index +
684 le32_to_cpu(ir->index.entries_offset));
685 /*
686 * Loop until we exceed valid memory (corruption case) or until we
687 * reach the last entry.
688 */
689 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
690 /* Bounds checks. */
691 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie +
692 sizeof(INDEX_ENTRY_HEADER) > index_end ||
693 (u8*)ie + le16_to_cpu(ie->key_length) >
694 index_end)
695 goto dir_err_out;
696 /*
697 * The last entry cannot contain a name. It can however contain
698 * a pointer to a child node in the B+tree so we just break out.
699 */
700 if (ie->flags & INDEX_ENTRY_END)
701 break;
702 /*
703 * If the current entry has a name type of POSIX, the name is
704 * case sensitive and not otherwise. This has the effect of us
705 * not being able to access any POSIX file names which collate
706 * after the non-POSIX one when they only differ in case, but
707 * anyone doing screwy stuff like that deserves to burn in
708 * hell... Doing that kind of stuff on NT4 actually causes
709 * corruption on the partition even when using SP6a and Linux
710 * is not involved at all.
711 */
712 ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
713 CASE_SENSITIVE;
714 /*
715 * If the names match perfectly, we are done and return the
716 * mft reference of the inode (i.e. the inode number together
717 * with the sequence number for consistency checking. We
718 * convert it to cpu format before returning.
719 */
720 if (ntfs_are_names_equal(uname, uname_len,
721 (ntfschar*)&ie->key.file_name.file_name,
722 ie->key.file_name.file_name_length, ic,
723 vol->upcase, vol->upcase_len)) {
724found_it:
725 mref = le64_to_cpu(ie->data.dir.indexed_file);
726 ntfs_attr_put_search_ctx(ctx);
727 unmap_mft_record(dir_ni);
728 return mref;
729 }
730 /*
731 * Not a perfect match, need to do full blown collation so we
732 * know which way in the B+tree we have to go.
733 */
734 rc = ntfs_collate_names(uname, uname_len,
735 (ntfschar*)&ie->key.file_name.file_name,
736 ie->key.file_name.file_name_length, 1,
737 IGNORE_CASE, vol->upcase, vol->upcase_len);
738 /*
739 * If uname collates before the name of the current entry, there
740 * is definitely no such name in this index but we might need to
741 * descend into the B+tree so we just break out of the loop.
742 */
743 if (rc == -1)
744 break;
745 /* The names are not equal, continue the search. */
746 if (rc)
747 continue;
748 /*
749 * Names match with case insensitive comparison, now try the
750 * case sensitive comparison, which is required for proper
751 * collation.
752 */
753 rc = ntfs_collate_names(uname, uname_len,
754 (ntfschar*)&ie->key.file_name.file_name,
755 ie->key.file_name.file_name_length, 1,
756 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
757 if (rc == -1)
758 break;
759 if (rc)
760 continue;
761 /*
762 * Perfect match, this will never happen as the
763 * ntfs_are_names_equal() call will have gotten a match but we
764 * still treat it correctly.
765 */
766 goto found_it;
767 }
768 /*
769 * We have finished with this index without success. Check for the
770 * presence of a child node.
771 */
772 if (!(ie->flags & INDEX_ENTRY_NODE)) {
773 /* No child node, return -ENOENT. */
774 err = -ENOENT;
775 goto err_out;
776 } /* Child node present, descend into it. */
777 /* Consistency check: Verify that an index allocation exists. */
778 if (!NInoIndexAllocPresent(dir_ni)) {
779 ntfs_error(sb, "No index allocation attribute but index entry "
780 "requires one. Directory inode 0x%lx is "
781 "corrupt or driver bug.", dir_ni->mft_no);
782 goto err_out;
783 }
784 /* Get the starting vcn of the index_block holding the child node. */
785 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
786 ia_mapping = VFS_I(dir_ni)->i_mapping;
787 /*
788 * We are done with the index root and the mft record. Release them,
789 * otherwise we deadlock with ntfs_map_page().
790 */
791 ntfs_attr_put_search_ctx(ctx);
792 unmap_mft_record(dir_ni);
793 m = NULL;
794 ctx = NULL;
795descend_into_child_node:
796 /*
797 * Convert vcn to index into the index allocation attribute in units
798 * of PAGE_CACHE_SIZE and map the page cache page, reading it from
799 * disk if necessary.
800 */
801 page = ntfs_map_page(ia_mapping, vcn <<
802 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
803 if (IS_ERR(page)) {
804 ntfs_error(sb, "Failed to map directory index page, error %ld.",
805 -PTR_ERR(page));
806 err = PTR_ERR(page);
807 goto err_out;
808 }
809 lock_page(page);
810 kaddr = (u8*)page_address(page);
811fast_descend_into_child_node:
812 /* Get to the index allocation block. */
813 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
814 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
815 /* Bounds checks. */
816 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
817 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
818 "inode 0x%lx or driver bug.", dir_ni->mft_no);
819 goto unm_err_out;
820 }
821 /* Catch multi sector transfer fixup errors. */
822 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
823 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
824 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
825 (unsigned long long)vcn, dir_ni->mft_no);
826 goto unm_err_out;
827 }
828 if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
829 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
830 "different from expected VCN (0x%llx). "
831 "Directory inode 0x%lx is corrupt or driver "
832 "bug.", (unsigned long long)
833 sle64_to_cpu(ia->index_block_vcn),
834 (unsigned long long)vcn, dir_ni->mft_no);
835 goto unm_err_out;
836 }
837 if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
838 dir_ni->itype.index.block_size) {
839 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
840 "0x%lx has a size (%u) differing from the "
841 "directory specified size (%u). Directory "
842 "inode is corrupt or driver bug.",
843 (unsigned long long)vcn, dir_ni->mft_no,
844 le32_to_cpu(ia->index.allocated_size) + 0x18,
845 dir_ni->itype.index.block_size);
846 goto unm_err_out;
847 }
848 index_end = (u8*)ia + dir_ni->itype.index.block_size;
849 if (index_end > kaddr + PAGE_CACHE_SIZE) {
850 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
851 "0x%lx crosses page boundary. Impossible! "
852 "Cannot access! This is probably a bug in the "
853 "driver.", (unsigned long long)vcn,
854 dir_ni->mft_no);
855 goto unm_err_out;
856 }
857 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
858 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) {
859 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
860 "inode 0x%lx exceeds maximum size.",
861 (unsigned long long)vcn, dir_ni->mft_no);
862 goto unm_err_out;
863 }
864 /* The first index entry. */
865 ie = (INDEX_ENTRY*)((u8*)&ia->index +
866 le32_to_cpu(ia->index.entries_offset));
867 /*
868 * Iterate similar to above big loop but applied to index buffer, thus
869 * loop until we exceed valid memory (corruption case) or until we
870 * reach the last entry.
871 */
872 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
873 /* Bounds check. */
874 if ((u8*)ie < (u8*)ia || (u8*)ie +
875 sizeof(INDEX_ENTRY_HEADER) > index_end ||
876 (u8*)ie + le16_to_cpu(ie->key_length) >
877 index_end) {
878 ntfs_error(sb, "Index entry out of bounds in "
879 "directory inode 0x%lx.",
880 dir_ni->mft_no);
881 goto unm_err_out;
882 }
883 /*
884 * The last entry cannot contain a name. It can however contain
885 * a pointer to a child node in the B+tree so we just break out.
886 */
887 if (ie->flags & INDEX_ENTRY_END)
888 break;
889 /*
890 * If the current entry has a name type of POSIX, the name is
891 * case sensitive and not otherwise. This has the effect of us
892 * not being able to access any POSIX file names which collate
893 * after the non-POSIX one when they only differ in case, but
894 * anyone doing screwy stuff like that deserves to burn in
895 * hell... Doing that kind of stuff on NT4 actually causes
896 * corruption on the partition even when using SP6a and Linux
897 * is not involved at all.
898 */
899 ic = ie->key.file_name.file_name_type ? IGNORE_CASE :
900 CASE_SENSITIVE;
901 /*
902 * If the names match perfectly, we are done and return the
903 * mft reference of the inode (i.e. the inode number together
904 * with the sequence number for consistency checking. We
905 * convert it to cpu format before returning.
906 */
907 if (ntfs_are_names_equal(uname, uname_len,
908 (ntfschar*)&ie->key.file_name.file_name,
909 ie->key.file_name.file_name_length, ic,
910 vol->upcase, vol->upcase_len)) {
911found_it2:
912 mref = le64_to_cpu(ie->data.dir.indexed_file);
913 unlock_page(page);
914 ntfs_unmap_page(page);
915 return mref;
916 }
917 /*
918 * Not a perfect match, need to do full blown collation so we
919 * know which way in the B+tree we have to go.
920 */
921 rc = ntfs_collate_names(uname, uname_len,
922 (ntfschar*)&ie->key.file_name.file_name,
923 ie->key.file_name.file_name_length, 1,
924 IGNORE_CASE, vol->upcase, vol->upcase_len);
925 /*
926 * If uname collates before the name of the current entry, there
927 * is definitely no such name in this index but we might need to
928 * descend into the B+tree so we just break out of the loop.
929 */
930 if (rc == -1)
931 break;
932 /* The names are not equal, continue the search. */
933 if (rc)
934 continue;
935 /*
936 * Names match with case insensitive comparison, now try the
937 * case sensitive comparison, which is required for proper
938 * collation.
939 */
940 rc = ntfs_collate_names(uname, uname_len,
941 (ntfschar*)&ie->key.file_name.file_name,
942 ie->key.file_name.file_name_length, 1,
943 CASE_SENSITIVE, vol->upcase, vol->upcase_len);
944 if (rc == -1)
945 break;
946 if (rc)
947 continue;
948 /*
949 * Perfect match, this will never happen as the
950 * ntfs_are_names_equal() call will have gotten a match but we
951 * still treat it correctly.
952 */
953 goto found_it2;
954 }
955 /*
956 * We have finished with this index buffer without success. Check for
957 * the presence of a child node.
958 */
959 if (ie->flags & INDEX_ENTRY_NODE) {
960 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
961 ntfs_error(sb, "Index entry with child node found in "
962 "a leaf node in directory inode 0x%lx.",
963 dir_ni->mft_no);
964 goto unm_err_out;
965 }
966 /* Child node present, descend into it. */
967 old_vcn = vcn;
968 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8);
969 if (vcn >= 0) {
970 /* If vcn is in the same page cache page as old_vcn we
971 * recycle the mapped page. */
972 if (old_vcn << vol->cluster_size_bits >>
973 PAGE_CACHE_SHIFT == vcn <<
974 vol->cluster_size_bits >>
975 PAGE_CACHE_SHIFT)
976 goto fast_descend_into_child_node;
977 unlock_page(page);
978 ntfs_unmap_page(page);
979 goto descend_into_child_node;
980 }
981 ntfs_error(sb, "Negative child node vcn in directory inode "
982 "0x%lx.", dir_ni->mft_no);
983 goto unm_err_out;
984 }
985 /* No child node, return -ENOENT. */
986 ntfs_debug("Entry not found.");
987 err = -ENOENT;
988unm_err_out:
989 unlock_page(page);
990 ntfs_unmap_page(page);
991err_out:
992 if (!err)
993 err = -EIO;
994 if (ctx)
995 ntfs_attr_put_search_ctx(ctx);
996 if (m)
997 unmap_mft_record(dir_ni);
998 return ERR_MREF(err);
999dir_err_out:
1000 ntfs_error(sb, "Corrupt directory. Aborting lookup.");
1001 goto err_out;
1002}
1003
1004#endif
1005
1006/**
1007 * ntfs_filldir - ntfs specific filldir method
1008 * @vol: current ntfs volume
1009 * @fpos: position in the directory
1010 * @ndir: ntfs inode of current directory
1011 * @ia_page: page in which the index allocation buffer @ie is in resides
1012 * @ie: current index entry
1013 * @name: buffer to use for the converted name
1014 * @dirent: vfs filldir callback context
1015 * @filldir: vfs filldir callback
1016 *
1017 * Convert the Unicode @name to the loaded NLS and pass it to the @filldir
1018 * callback.
1019 *
1020 * If @ia_page is not NULL it is the locked page containing the index
1021 * allocation block containing the index entry @ie.
1022 *
1023 * Note, we drop (and then reacquire) the page lock on @ia_page across the
1024 * @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup
1025 * since ntfs_lookup() will lock the same page. As an optimization, we do not
1026 * retake the lock if we are returning a non-zero value as ntfs_readdir()
1027 * would need to drop the lock immediately anyway.
1028 */
1029static inline int ntfs_filldir(ntfs_volume *vol, loff_t fpos,
1030 ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie,
1031 u8 *name, void *dirent, filldir_t filldir)
1032{
1033 unsigned long mref;
1034 int name_len, rc;
1035 unsigned dt_type;
1036 FILE_NAME_TYPE_FLAGS name_type;
1037
1038 name_type = ie->key.file_name.file_name_type;
1039 if (name_type == FILE_NAME_DOS) {
1040 ntfs_debug("Skipping DOS name space entry.");
1041 return 0;
1042 }
1043 if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) {
1044 ntfs_debug("Skipping root directory self reference entry.");
1045 return 0;
1046 }
1047 if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user &&
1048 !NVolShowSystemFiles(vol)) {
1049 ntfs_debug("Skipping system file.");
1050 return 0;
1051 }
1052 name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name,
1053 ie->key.file_name.file_name_length, &name,
1054 NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1);
1055 if (name_len <= 0) {
1056 ntfs_debug("Skipping unrepresentable file.");
1057 return 0;
1058 }
1059 if (ie->key.file_name.file_attributes &
1060 FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT)
1061 dt_type = DT_DIR;
1062 else
1063 dt_type = DT_REG;
1064 mref = MREF_LE(ie->data.dir.indexed_file);
1065 /*
1066 * Drop the page lock otherwise we deadlock with NFS when it calls
1067 * ->lookup since ntfs_lookup() will lock the same page.
1068 */
1069 if (ia_page)
1070 unlock_page(ia_page);
1071 ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode "
1072 "0x%lx, DT_%s.", name, name_len, fpos, mref,
1073 dt_type == DT_DIR ? "DIR" : "REG");
1074 rc = filldir(dirent, name, name_len, fpos, mref, dt_type);
1075 /* Relock the page but not if we are aborting ->readdir. */
1076 if (!rc && ia_page)
1077 lock_page(ia_page);
1078 return rc;
1079}
1080
1081/*
1082 * We use the same basic approach as the old NTFS driver, i.e. we parse the
1083 * index root entries and then the index allocation entries that are marked
1084 * as in use in the index bitmap.
1085 *
1086 * While this will return the names in random order this doesn't matter for
1087 * ->readdir but OTOH results in a faster ->readdir.
1088 *
1089 * VFS calls ->readdir without BKL but with i_sem held. This protects the VFS
1090 * parts (e.g. ->f_pos and ->i_size, and it also protects against directory
1091 * modifications).
1092 *
1093 * Locking: - Caller must hold i_sem on the directory.
1094 * - Each page cache page in the index allocation mapping must be
1095 * locked whilst being accessed otherwise we may find a corrupt
1096 * page due to it being under ->writepage at the moment which
1097 * applies the mst protection fixups before writing out and then
1098 * removes them again after the write is complete after which it
1099 * unlocks the page.
1100 */
1101static int ntfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1102{
1103 s64 ia_pos, ia_start, prev_ia_pos, bmp_pos;
1104 loff_t fpos;
1105 struct inode *bmp_vi, *vdir = filp->f_dentry->d_inode;
1106 struct super_block *sb = vdir->i_sb;
1107 ntfs_inode *ndir = NTFS_I(vdir);
1108 ntfs_volume *vol = NTFS_SB(sb);
1109 MFT_RECORD *m;
1110 INDEX_ROOT *ir = NULL;
1111 INDEX_ENTRY *ie;
1112 INDEX_ALLOCATION *ia;
1113 u8 *name = NULL;
1114 int rc, err, ir_pos, cur_bmp_pos;
1115 struct address_space *ia_mapping, *bmp_mapping;
1116 struct page *bmp_page = NULL, *ia_page = NULL;
1117 u8 *kaddr, *bmp, *index_end;
1118 ntfs_attr_search_ctx *ctx;
1119
1120 fpos = filp->f_pos;
1121 ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.",
1122 vdir->i_ino, fpos);
1123 rc = err = 0;
1124 /* Are we at end of dir yet? */
1125 if (fpos >= vdir->i_size + vol->mft_record_size)
1126 goto done;
1127 /* Emulate . and .. for all directories. */
1128 if (!fpos) {
1129 ntfs_debug("Calling filldir for . with len 1, fpos 0x0, "
1130 "inode 0x%lx, DT_DIR.", vdir->i_ino);
1131 rc = filldir(dirent, ".", 1, fpos, vdir->i_ino, DT_DIR);
1132 if (rc)
1133 goto done;
1134 fpos++;
1135 }
1136 if (fpos == 1) {
1137 ntfs_debug("Calling filldir for .. with len 2, fpos 0x1, "
1138 "inode 0x%lx, DT_DIR.",
1139 parent_ino(filp->f_dentry));
1140 rc = filldir(dirent, "..", 2, fpos,
1141 parent_ino(filp->f_dentry), DT_DIR);
1142 if (rc)
1143 goto done;
1144 fpos++;
1145 }
1146 m = NULL;
1147 ctx = NULL;
1148 /*
1149 * Allocate a buffer to store the current name being processed
1150 * converted to format determined by current NLS.
1151 */
1152 name = (u8*)kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1,
1153 GFP_NOFS);
1154 if (unlikely(!name)) {
1155 err = -ENOMEM;
1156 goto err_out;
1157 }
1158 /* Are we jumping straight into the index allocation attribute? */
1159 if (fpos >= vol->mft_record_size)
1160 goto skip_index_root;
1161 /* Get hold of the mft record for the directory. */
1162 m = map_mft_record(ndir);
1163 if (IS_ERR(m)) {
1164 err = PTR_ERR(m);
1165 m = NULL;
1166 goto err_out;
1167 }
1168 ctx = ntfs_attr_get_search_ctx(ndir, m);
1169 if (unlikely(!ctx)) {
1170 err = -ENOMEM;
1171 goto err_out;
1172 }
1173 /* Get the offset into the index root attribute. */
1174 ir_pos = (s64)fpos;
1175 /* Find the index root attribute in the mft record. */
1176 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL,
1177 0, ctx);
1178 if (unlikely(err)) {
1179 ntfs_error(sb, "Index root attribute missing in directory "
1180 "inode 0x%lx.", vdir->i_ino);
1181 goto err_out;
1182 }
1183 /*
1184 * Copy the index root attribute value to a buffer so that we can put
1185 * the search context and unmap the mft record before calling the
1186 * filldir() callback. We need to do this because of NFSd which calls
1187 * ->lookup() from its filldir callback() and this causes NTFS to
1188 * deadlock as ntfs_lookup() maps the mft record of the directory and
1189 * we have got it mapped here already. The only solution is for us to
1190 * unmap the mft record here so that a call to ntfs_lookup() is able to
1191 * map the mft record without deadlocking.
1192 */
1193 rc = le32_to_cpu(ctx->attr->data.resident.value_length);
1194 ir = (INDEX_ROOT*)kmalloc(rc, GFP_NOFS);
1195 if (unlikely(!ir)) {
1196 err = -ENOMEM;
1197 goto err_out;
1198 }
1199 /* Copy the index root value (it has been verified in read_inode). */
1200 memcpy(ir, (u8*)ctx->attr +
1201 le16_to_cpu(ctx->attr->data.resident.value_offset), rc);
1202 ntfs_attr_put_search_ctx(ctx);
1203 unmap_mft_record(ndir);
1204 ctx = NULL;
1205 m = NULL;
1206 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
1207 /* The first index entry. */
1208 ie = (INDEX_ENTRY*)((u8*)&ir->index +
1209 le32_to_cpu(ir->index.entries_offset));
1210 /*
1211 * Loop until we exceed valid memory (corruption case) or until we
1212 * reach the last entry or until filldir tells us it has had enough
1213 * or signals an error (both covered by the rc test).
1214 */
1215 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
1216 ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir);
1217 /* Bounds checks. */
1218 if (unlikely((u8*)ie < (u8*)ir || (u8*)ie +
1219 sizeof(INDEX_ENTRY_HEADER) > index_end ||
1220 (u8*)ie + le16_to_cpu(ie->key_length) >
1221 index_end))
1222 goto err_out;
1223 /* The last entry cannot contain a name. */
1224 if (ie->flags & INDEX_ENTRY_END)
1225 break;
1226 /* Skip index root entry if continuing previous readdir. */
1227 if (ir_pos > (u8*)ie - (u8*)ir)
1228 continue;
1229 /* Advance the position even if going to skip the entry. */
1230 fpos = (u8*)ie - (u8*)ir;
1231 /* Submit the name to the filldir callback. */
1232 rc = ntfs_filldir(vol, fpos, ndir, NULL, ie, name, dirent,
1233 filldir);
1234 if (rc) {
1235 kfree(ir);
1236 goto abort;
1237 }
1238 }
1239 /* We are done with the index root and can free the buffer. */
1240 kfree(ir);
1241 ir = NULL;
1242 /* If there is no index allocation attribute we are finished. */
1243 if (!NInoIndexAllocPresent(ndir))
1244 goto EOD;
1245 /* Advance fpos to the beginning of the index allocation. */
1246 fpos = vol->mft_record_size;
1247skip_index_root:
1248 kaddr = NULL;
1249 prev_ia_pos = -1LL;
1250 /* Get the offset into the index allocation attribute. */
1251 ia_pos = (s64)fpos - vol->mft_record_size;
1252 ia_mapping = vdir->i_mapping;
1253 bmp_vi = ndir->itype.index.bmp_ino;
1254 if (unlikely(!bmp_vi)) {
1255 ntfs_debug("Inode 0x%lx, regetting index bitmap.", vdir->i_ino);
1256 bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4);
1257 if (IS_ERR(bmp_vi)) {
1258 ntfs_error(sb, "Failed to get bitmap attribute.");
1259 err = PTR_ERR(bmp_vi);
1260 goto err_out;
1261 }
1262 ndir->itype.index.bmp_ino = bmp_vi;
1263 }
1264 bmp_mapping = bmp_vi->i_mapping;
1265 /* Get the starting bitmap bit position and sanity check it. */
1266 bmp_pos = ia_pos >> ndir->itype.index.block_size_bits;
1267 if (unlikely(bmp_pos >> 3 >= bmp_vi->i_size)) {
1268 ntfs_error(sb, "Current index allocation position exceeds "
1269 "index bitmap size.");
1270 goto err_out;
1271 }
1272 /* Get the starting bit position in the current bitmap page. */
1273 cur_bmp_pos = bmp_pos & ((PAGE_CACHE_SIZE * 8) - 1);
1274 bmp_pos &= ~(u64)((PAGE_CACHE_SIZE * 8) - 1);
1275get_next_bmp_page:
1276 ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx",
1277 (unsigned long long)bmp_pos >> (3 + PAGE_CACHE_SHIFT),
1278 (unsigned long long)bmp_pos &
1279 (unsigned long long)((PAGE_CACHE_SIZE * 8) - 1));
1280 bmp_page = ntfs_map_page(bmp_mapping,
1281 bmp_pos >> (3 + PAGE_CACHE_SHIFT));
1282 if (IS_ERR(bmp_page)) {
1283 ntfs_error(sb, "Reading index bitmap failed.");
1284 err = PTR_ERR(bmp_page);
1285 bmp_page = NULL;
1286 goto err_out;
1287 }
1288 bmp = (u8*)page_address(bmp_page);
1289 /* Find next index block in use. */
1290 while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) {
1291find_next_index_buffer:
1292 cur_bmp_pos++;
1293 /*
1294 * If we have reached the end of the bitmap page, get the next
1295 * page, and put away the old one.
1296 */
1297 if (unlikely((cur_bmp_pos >> 3) >= PAGE_CACHE_SIZE)) {
1298 ntfs_unmap_page(bmp_page);
1299 bmp_pos += PAGE_CACHE_SIZE * 8;
1300 cur_bmp_pos = 0;
1301 goto get_next_bmp_page;
1302 }
1303 /* If we have reached the end of the bitmap, we are done. */
1304 if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= vdir->i_size))
1305 goto unm_EOD;
1306 ia_pos = (bmp_pos + cur_bmp_pos) <<
1307 ndir->itype.index.block_size_bits;
1308 }
1309 ntfs_debug("Handling index buffer 0x%llx.",
1310 (unsigned long long)bmp_pos + cur_bmp_pos);
1311 /* If the current index buffer is in the same page we reuse the page. */
1312 if ((prev_ia_pos & PAGE_CACHE_MASK) != (ia_pos & PAGE_CACHE_MASK)) {
1313 prev_ia_pos = ia_pos;
1314 if (likely(ia_page != NULL)) {
1315 unlock_page(ia_page);
1316 ntfs_unmap_page(ia_page);
1317 }
1318 /*
1319 * Map the page cache page containing the current ia_pos,
1320 * reading it from disk if necessary.
1321 */
1322 ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_CACHE_SHIFT);
1323 if (IS_ERR(ia_page)) {
1324 ntfs_error(sb, "Reading index allocation data failed.");
1325 err = PTR_ERR(ia_page);
1326 ia_page = NULL;
1327 goto err_out;
1328 }
1329 lock_page(ia_page);
1330 kaddr = (u8*)page_address(ia_page);
1331 }
1332 /* Get the current index buffer. */
1333 ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_CACHE_MASK &
1334 ~(s64)(ndir->itype.index.block_size - 1)));
1335 /* Bounds checks. */
1336 if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE)) {
1337 ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
1338 "inode 0x%lx or driver bug.", vdir->i_ino);
1339 goto err_out;
1340 }
1341 /* Catch multi sector transfer fixup errors. */
1342 if (unlikely(!ntfs_is_indx_record(ia->magic))) {
1343 ntfs_error(sb, "Directory index record with vcn 0x%llx is "
1344 "corrupt. Corrupt inode 0x%lx. Run chkdsk.",
1345 (unsigned long long)ia_pos >>
1346 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1347 goto err_out;
1348 }
1349 if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos &
1350 ~(s64)(ndir->itype.index.block_size - 1)) >>
1351 ndir->itype.index.vcn_size_bits)) {
1352 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
1353 "different from expected VCN (0x%llx). "
1354 "Directory inode 0x%lx is corrupt or driver "
1355 "bug. ", (unsigned long long)
1356 sle64_to_cpu(ia->index_block_vcn),
1357 (unsigned long long)ia_pos >>
1358 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1359 goto err_out;
1360 }
1361 if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 !=
1362 ndir->itype.index.block_size)) {
1363 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
1364 "0x%lx has a size (%u) differing from the "
1365 "directory specified size (%u). Directory "
1366 "inode is corrupt or driver bug.",
1367 (unsigned long long)ia_pos >>
1368 ndir->itype.index.vcn_size_bits, vdir->i_ino,
1369 le32_to_cpu(ia->index.allocated_size) + 0x18,
1370 ndir->itype.index.block_size);
1371 goto err_out;
1372 }
1373 index_end = (u8*)ia + ndir->itype.index.block_size;
1374 if (unlikely(index_end > kaddr + PAGE_CACHE_SIZE)) {
1375 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
1376 "0x%lx crosses page boundary. Impossible! "
1377 "Cannot access! This is probably a bug in the "
1378 "driver.", (unsigned long long)ia_pos >>
1379 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1380 goto err_out;
1381 }
1382 ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1);
1383 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
1384 if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) {
1385 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory "
1386 "inode 0x%lx exceeds maximum size.",
1387 (unsigned long long)ia_pos >>
1388 ndir->itype.index.vcn_size_bits, vdir->i_ino);
1389 goto err_out;
1390 }
1391 /* The first index entry in this index buffer. */
1392 ie = (INDEX_ENTRY*)((u8*)&ia->index +
1393 le32_to_cpu(ia->index.entries_offset));
1394 /*
1395 * Loop until we exceed valid memory (corruption case) or until we
1396 * reach the last entry or until filldir tells us it has had enough
1397 * or signals an error (both covered by the rc test).
1398 */
1399 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
1400 ntfs_debug("In index allocation, offset 0x%llx.",
1401 (unsigned long long)ia_start +
1402 (unsigned long long)((u8*)ie - (u8*)ia));
1403 /* Bounds checks. */
1404 if (unlikely((u8*)ie < (u8*)ia || (u8*)ie +
1405 sizeof(INDEX_ENTRY_HEADER) > index_end ||
1406 (u8*)ie + le16_to_cpu(ie->key_length) >
1407 index_end))
1408 goto err_out;
1409 /* The last entry cannot contain a name. */
1410 if (ie->flags & INDEX_ENTRY_END)
1411 break;
1412 /* Skip index block entry if continuing previous readdir. */
1413 if (ia_pos - ia_start > (u8*)ie - (u8*)ia)
1414 continue;
1415 /* Advance the position even if going to skip the entry. */
1416 fpos = (u8*)ie - (u8*)ia +
1417 (sle64_to_cpu(ia->index_block_vcn) <<
1418 ndir->itype.index.vcn_size_bits) +
1419 vol->mft_record_size;
1420 /*
1421 * Submit the name to the @filldir callback. Note,
1422 * ntfs_filldir() drops the lock on @ia_page but it retakes it
1423 * before returning, unless a non-zero value is returned in
1424 * which case the page is left unlocked.
1425 */
1426 rc = ntfs_filldir(vol, fpos, ndir, ia_page, ie, name, dirent,
1427 filldir);
1428 if (rc) {
1429 /* @ia_page is already unlocked in this case. */
1430 ntfs_unmap_page(ia_page);
1431 ntfs_unmap_page(bmp_page);
1432 goto abort;
1433 }
1434 }
1435 goto find_next_index_buffer;
1436unm_EOD:
1437 if (ia_page) {
1438 unlock_page(ia_page);
1439 ntfs_unmap_page(ia_page);
1440 }
1441 ntfs_unmap_page(bmp_page);
1442EOD:
1443 /* We are finished, set fpos to EOD. */
1444 fpos = vdir->i_size + vol->mft_record_size;
1445abort:
1446 kfree(name);
1447done:
1448#ifdef DEBUG
1449 if (!rc)
1450 ntfs_debug("EOD, fpos 0x%llx, returning 0.", fpos);
1451 else
1452 ntfs_debug("filldir returned %i, fpos 0x%llx, returning 0.",
1453 rc, fpos);
1454#endif
1455 filp->f_pos = fpos;
1456 return 0;
1457err_out:
1458 if (bmp_page)
1459 ntfs_unmap_page(bmp_page);
1460 if (ia_page) {
1461 unlock_page(ia_page);
1462 ntfs_unmap_page(ia_page);
1463 }
1464 if (ir)
1465 kfree(ir);
1466 if (name)
1467 kfree(name);
1468 if (ctx)
1469 ntfs_attr_put_search_ctx(ctx);
1470 if (m)
1471 unmap_mft_record(ndir);
1472 if (!err)
1473 err = -EIO;
1474 ntfs_debug("Failed. Returning error code %i.", -err);
1475 filp->f_pos = fpos;
1476 return err;
1477}
1478
1479/**
1480 * ntfs_dir_open - called when an inode is about to be opened
1481 * @vi: inode to be opened
1482 * @filp: file structure describing the inode
1483 *
1484 * Limit directory size to the page cache limit on architectures where unsigned
1485 * long is 32-bits. This is the most we can do for now without overflowing the
1486 * page cache page index. Doing it this way means we don't run into problems
1487 * because of existing too large directories. It would be better to allow the
1488 * user to read the accessible part of the directory but I doubt very much
1489 * anyone is going to hit this check on a 32-bit architecture, so there is no
1490 * point in adding the extra complexity required to support this.
1491 *
1492 * On 64-bit architectures, the check is hopefully optimized away by the
1493 * compiler.
1494 */
1495static int ntfs_dir_open(struct inode *vi, struct file *filp)
1496{
1497 if (sizeof(unsigned long) < 8) {
1498 if (vi->i_size > MAX_LFS_FILESIZE)
1499 return -EFBIG;
1500 }
1501 return 0;
1502}
1503
1504#ifdef NTFS_RW
1505
1506/**
1507 * ntfs_dir_fsync - sync a directory to disk
1508 * @filp: directory to be synced
1509 * @dentry: dentry describing the directory to sync
1510 * @datasync: if non-zero only flush user data and not metadata
1511 *
1512 * Data integrity sync of a directory to disk. Used for fsync, fdatasync, and
1513 * msync system calls. This function is based on file.c::ntfs_file_fsync().
1514 *
1515 * Write the mft record and all associated extent mft records as well as the
1516 * $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device.
1517 *
1518 * If @datasync is true, we do not wait on the inode(s) to be written out
1519 * but we always wait on the page cache pages to be written out.
1520 *
1521 * Note: In the past @filp could be NULL so we ignore it as we don't need it
1522 * anyway.
1523 *
1524 * Locking: Caller must hold i_sem on the inode.
1525 *
1526 * TODO: We should probably also write all attribute/index inodes associated
1527 * with this inode but since we have no simple way of getting to them we ignore
1528 * this problem for now. We do write the $BITMAP attribute if it is present
1529 * which is the important one for a directory so things are not too bad.
1530 */
1531static int ntfs_dir_fsync(struct file *filp, struct dentry *dentry,
1532 int datasync)
1533{
1534 struct inode *vi = dentry->d_inode;
1535 ntfs_inode *ni = NTFS_I(vi);
1536 int err, ret;
1537
1538 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1539 BUG_ON(!S_ISDIR(vi->i_mode));
1540 if (NInoIndexAllocPresent(ni) && ni->itype.index.bmp_ino)
1541 write_inode_now(ni->itype.index.bmp_ino, !datasync);
1542 ret = ntfs_write_inode(vi, 1);
1543 write_inode_now(vi, !datasync);
1544 err = sync_blockdev(vi->i_sb->s_bdev);
1545 if (unlikely(err && !ret))
1546 ret = err;
1547 if (likely(!ret))
1548 ntfs_debug("Done.");
1549 else
1550 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
1551 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
1552 return ret;
1553}
1554
1555#endif /* NTFS_RW */
1556
1557struct file_operations ntfs_dir_ops = {
1558 .llseek = generic_file_llseek, /* Seek inside directory. */
1559 .read = generic_read_dir, /* Return -EISDIR. */
1560 .readdir = ntfs_readdir, /* Read directory contents. */
1561#ifdef NTFS_RW
1562 .fsync = ntfs_dir_fsync, /* Sync a directory to disk. */
1563 /*.aio_fsync = ,*/ /* Sync all outstanding async
1564 i/o operations on a kiocb. */
1565#endif /* NTFS_RW */
1566 /*.ioctl = ,*/ /* Perform function on the
1567 mounted filesystem. */
1568 .open = ntfs_dir_open, /* Open directory. */
1569};
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-18 16:35:24 -0500