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1da177e4 LT |
1 | /** |
2 | * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project. | |
3 | * | |
b6ad6c52 | 4 | * Copyright (c) 2001-2005 Anton Altaparmakov |
1da177e4 LT |
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/buffer_head.h> | |
24 | ||
25 | #include "attrib.h" | |
26 | #include "debug.h" | |
27 | #include "layout.h" | |
28 | #include "mft.h" | |
29 | #include "ntfs.h" | |
30 | #include "types.h" | |
31 | ||
32 | /** | |
b6ad6c52 | 33 | * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode |
1da177e4 LT |
34 | * @ni: ntfs inode for which to map (part of) a runlist |
35 | * @vcn: map runlist part containing this vcn | |
36 | * | |
37 | * Map the part of a runlist containing the @vcn of the ntfs inode @ni. | |
38 | * | |
39 | * Return 0 on success and -errno on error. | |
40 | * | |
b6ad6c52 AA |
41 | * Locking: - The runlist must be locked for writing. |
42 | * - This function modifies the runlist. | |
1da177e4 | 43 | */ |
b6ad6c52 | 44 | int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) |
1da177e4 LT |
45 | { |
46 | ntfs_inode *base_ni; | |
1da177e4 | 47 | MFT_RECORD *mrec; |
b6ad6c52 AA |
48 | ntfs_attr_search_ctx *ctx; |
49 | runlist_element *rl; | |
1da177e4 LT |
50 | int err = 0; |
51 | ||
52 | ntfs_debug("Mapping runlist part containing vcn 0x%llx.", | |
53 | (unsigned long long)vcn); | |
1da177e4 LT |
54 | if (!NInoAttr(ni)) |
55 | base_ni = ni; | |
56 | else | |
57 | base_ni = ni->ext.base_ntfs_ino; | |
1da177e4 LT |
58 | mrec = map_mft_record(base_ni); |
59 | if (IS_ERR(mrec)) | |
60 | return PTR_ERR(mrec); | |
61 | ctx = ntfs_attr_get_search_ctx(base_ni, mrec); | |
62 | if (unlikely(!ctx)) { | |
63 | err = -ENOMEM; | |
64 | goto err_out; | |
65 | } | |
66 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
67 | CASE_SENSITIVE, vcn, NULL, 0, ctx); | |
b6ad6c52 | 68 | if (likely(!err)) { |
1da177e4 LT |
69 | rl = ntfs_mapping_pairs_decompress(ni->vol, ctx->attr, |
70 | ni->runlist.rl); | |
71 | if (IS_ERR(rl)) | |
72 | err = PTR_ERR(rl); | |
73 | else | |
74 | ni->runlist.rl = rl; | |
75 | } | |
1da177e4 LT |
76 | ntfs_attr_put_search_ctx(ctx); |
77 | err_out: | |
78 | unmap_mft_record(base_ni); | |
79 | return err; | |
80 | } | |
81 | ||
82 | /** | |
b6ad6c52 AA |
83 | * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode |
84 | * @ni: ntfs inode for which to map (part of) a runlist | |
85 | * @vcn: map runlist part containing this vcn | |
86 | * | |
87 | * Map the part of a runlist containing the @vcn of the ntfs inode @ni. | |
88 | * | |
89 | * Return 0 on success and -errno on error. | |
90 | * | |
91 | * Locking: - The runlist must be unlocked on entry and is unlocked on return. | |
92 | * - This function takes the runlist lock for writing and modifies the | |
93 | * runlist. | |
94 | */ | |
95 | int ntfs_map_runlist(ntfs_inode *ni, VCN vcn) | |
96 | { | |
97 | int err = 0; | |
98 | ||
99 | down_write(&ni->runlist.lock); | |
100 | /* Make sure someone else didn't do the work while we were sleeping. */ | |
101 | if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <= | |
102 | LCN_RL_NOT_MAPPED)) | |
103 | err = ntfs_map_runlist_nolock(ni, vcn); | |
104 | up_write(&ni->runlist.lock); | |
105 | return err; | |
106 | } | |
107 | ||
271849a9 AA |
108 | /** |
109 | * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode | |
110 | * @ni: ntfs inode of the attribute whose runlist to search | |
111 | * @vcn: vcn to convert | |
112 | * @write_locked: true if the runlist is locked for writing | |
113 | * | |
114 | * Find the virtual cluster number @vcn in the runlist of the ntfs attribute | |
115 | * described by the ntfs inode @ni and return the corresponding logical cluster | |
116 | * number (lcn). | |
117 | * | |
118 | * If the @vcn is not mapped yet, the attempt is made to map the attribute | |
119 | * extent containing the @vcn and the vcn to lcn conversion is retried. | |
120 | * | |
121 | * If @write_locked is true the caller has locked the runlist for writing and | |
122 | * if false for reading. | |
123 | * | |
124 | * Since lcns must be >= 0, we use negative return codes with special meaning: | |
125 | * | |
126 | * Return code Meaning / Description | |
127 | * ========================================== | |
128 | * LCN_HOLE Hole / not allocated on disk. | |
129 | * LCN_ENOENT There is no such vcn in the runlist, i.e. @vcn is out of bounds. | |
130 | * LCN_ENOMEM Not enough memory to map runlist. | |
131 | * LCN_EIO Critical error (runlist/file is corrupt, i/o error, etc). | |
132 | * | |
133 | * Locking: - The runlist must be locked on entry and is left locked on return. | |
134 | * - If @write_locked is FALSE, i.e. the runlist is locked for reading, | |
135 | * the lock may be dropped inside the function so you cannot rely on | |
136 | * the runlist still being the same when this function returns. | |
137 | */ | |
138 | LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, | |
139 | const BOOL write_locked) | |
140 | { | |
141 | LCN lcn; | |
142 | BOOL is_retry = FALSE; | |
143 | ||
144 | ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.", | |
145 | ni->mft_no, (unsigned long long)vcn, | |
146 | write_locked ? "write" : "read"); | |
147 | BUG_ON(!ni); | |
148 | BUG_ON(!NInoNonResident(ni)); | |
149 | BUG_ON(vcn < 0); | |
150 | retry_remap: | |
151 | /* Convert vcn to lcn. If that fails map the runlist and retry once. */ | |
152 | lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn); | |
153 | if (likely(lcn >= LCN_HOLE)) { | |
154 | ntfs_debug("Done, lcn 0x%llx.", (long long)lcn); | |
155 | return lcn; | |
156 | } | |
157 | if (lcn != LCN_RL_NOT_MAPPED) { | |
158 | if (lcn != LCN_ENOENT) | |
159 | lcn = LCN_EIO; | |
160 | } else if (!is_retry) { | |
161 | int err; | |
162 | ||
163 | if (!write_locked) { | |
164 | up_read(&ni->runlist.lock); | |
165 | down_write(&ni->runlist.lock); | |
166 | if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) != | |
167 | LCN_RL_NOT_MAPPED)) { | |
168 | up_write(&ni->runlist.lock); | |
169 | down_read(&ni->runlist.lock); | |
170 | goto retry_remap; | |
171 | } | |
172 | } | |
173 | err = ntfs_map_runlist_nolock(ni, vcn); | |
174 | if (!write_locked) { | |
175 | up_write(&ni->runlist.lock); | |
176 | down_read(&ni->runlist.lock); | |
177 | } | |
178 | if (likely(!err)) { | |
179 | is_retry = TRUE; | |
180 | goto retry_remap; | |
181 | } | |
182 | if (err == -ENOENT) | |
183 | lcn = LCN_ENOENT; | |
184 | else if (err == -ENOMEM) | |
185 | lcn = LCN_ENOMEM; | |
186 | else | |
187 | lcn = LCN_EIO; | |
188 | } | |
189 | if (lcn != LCN_ENOENT) | |
190 | ntfs_error(ni->vol->sb, "Failed with error code %lli.", | |
191 | (long long)lcn); | |
192 | return lcn; | |
193 | } | |
194 | ||
b6ad6c52 AA |
195 | /** |
196 | * ntfs_find_vcn_nolock - find a vcn in the runlist described by an ntfs inode | |
197 | * @ni: ntfs inode describing the runlist to search | |
198 | * @vcn: vcn to find | |
199 | * @write_locked: true if the runlist is locked for writing | |
1da177e4 LT |
200 | * |
201 | * Find the virtual cluster number @vcn in the runlist described by the ntfs | |
202 | * inode @ni and return the address of the runlist element containing the @vcn. | |
b6ad6c52 AA |
203 | * The runlist is left locked and the caller has to unlock it. In the error |
204 | * case, the runlist is left in the same locking state as on entry. | |
205 | * | |
206 | * Note if @write_locked is FALSE the lock may be dropped inside the function | |
207 | * so you cannot rely on the runlist still being the same when this function | |
208 | * returns. | |
1da177e4 LT |
209 | * |
210 | * Note you need to distinguish between the lcn of the returned runlist element | |
211 | * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on | |
212 | * read and allocate clusters on write. | |
213 | * | |
214 | * Return the runlist element containing the @vcn on success and | |
215 | * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR() | |
216 | * to decide if the return is success or failure and PTR_ERR() to get to the | |
217 | * error code if IS_ERR() is true. | |
218 | * | |
219 | * The possible error return codes are: | |
220 | * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds. | |
221 | * -ENOMEM - Not enough memory to map runlist. | |
222 | * -EIO - Critical error (runlist/file is corrupt, i/o error, etc). | |
223 | * | |
224 | * Locking: - The runlist must be unlocked on entry. | |
225 | * - On failing return, the runlist is unlocked. | |
226 | * - On successful return, the runlist is locked. If @need_write us | |
227 | * true, it is locked for writing. Otherwise is is locked for | |
228 | * reading. | |
229 | */ | |
b6ad6c52 AA |
230 | runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, |
231 | const BOOL write_locked) | |
1da177e4 LT |
232 | { |
233 | runlist_element *rl; | |
234 | int err = 0; | |
235 | BOOL is_retry = FALSE; | |
236 | ||
b6ad6c52 | 237 | ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.", |
1da177e4 | 238 | ni->mft_no, (unsigned long long)vcn, |
b6ad6c52 | 239 | write_locked ? "write" : "read"); |
1da177e4 LT |
240 | BUG_ON(!ni); |
241 | BUG_ON(!NInoNonResident(ni)); | |
242 | BUG_ON(vcn < 0); | |
b6ad6c52 | 243 | retry_remap: |
1da177e4 LT |
244 | rl = ni->runlist.rl; |
245 | if (likely(rl && vcn >= rl[0].vcn)) { | |
246 | while (likely(rl->length)) { | |
b6ad6c52 | 247 | if (unlikely(vcn < rl[1].vcn)) { |
1da177e4 LT |
248 | if (likely(rl->lcn >= LCN_HOLE)) { |
249 | ntfs_debug("Done."); | |
250 | return rl; | |
251 | } | |
252 | break; | |
253 | } | |
254 | rl++; | |
255 | } | |
256 | if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) { | |
257 | if (likely(rl->lcn == LCN_ENOENT)) | |
258 | err = -ENOENT; | |
259 | else | |
260 | err = -EIO; | |
261 | } | |
262 | } | |
1da177e4 LT |
263 | if (!err && !is_retry) { |
264 | /* | |
265 | * The @vcn is in an unmapped region, map the runlist and | |
266 | * retry. | |
267 | */ | |
b6ad6c52 AA |
268 | if (!write_locked) { |
269 | up_read(&ni->runlist.lock); | |
270 | down_write(&ni->runlist.lock); | |
271 | } | |
272 | err = ntfs_map_runlist_nolock(ni, vcn); | |
273 | if (!write_locked) { | |
274 | up_write(&ni->runlist.lock); | |
275 | down_read(&ni->runlist.lock); | |
276 | } | |
1da177e4 LT |
277 | if (likely(!err)) { |
278 | is_retry = TRUE; | |
b6ad6c52 | 279 | goto retry_remap; |
1da177e4 LT |
280 | } |
281 | /* | |
282 | * -EINVAL and -ENOENT coming from a failed mapping attempt are | |
283 | * equivalent to i/o errors for us as they should not happen in | |
284 | * our code paths. | |
285 | */ | |
286 | if (err == -EINVAL || err == -ENOENT) | |
287 | err = -EIO; | |
288 | } else if (!err) | |
289 | err = -EIO; | |
b6ad6c52 AA |
290 | if (err != -ENOENT) |
291 | ntfs_error(ni->vol->sb, "Failed with error code %i.", err); | |
1da177e4 LT |
292 | return ERR_PTR(err); |
293 | } | |
294 | ||
295 | /** | |
296 | * ntfs_attr_find - find (next) attribute in mft record | |
297 | * @type: attribute type to find | |
298 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
299 | * @name_len: attribute name length (only needed if @name present) | |
300 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
301 | * @val: attribute value to find (optional, resident attributes only) | |
302 | * @val_len: attribute value length | |
303 | * @ctx: search context with mft record and attribute to search from | |
304 | * | |
305 | * You should not need to call this function directly. Use ntfs_attr_lookup() | |
306 | * instead. | |
307 | * | |
308 | * ntfs_attr_find() takes a search context @ctx as parameter and searches the | |
309 | * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an | |
310 | * attribute of @type, optionally @name and @val. | |
311 | * | |
312 | * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will | |
313 | * point to the found attribute. | |
314 | * | |
315 | * If the attribute is not found, ntfs_attr_find() returns -ENOENT and | |
316 | * @ctx->attr will point to the attribute before which the attribute being | |
317 | * searched for would need to be inserted if such an action were to be desired. | |
318 | * | |
319 | * On actual error, ntfs_attr_find() returns -EIO. In this case @ctx->attr is | |
320 | * undefined and in particular do not rely on it not changing. | |
321 | * | |
322 | * If @ctx->is_first is TRUE, the search begins with @ctx->attr itself. If it | |
323 | * is FALSE, the search begins after @ctx->attr. | |
324 | * | |
325 | * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and | |
326 | * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record | |
327 | * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at | |
328 | * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case | |
329 | * sensitive. When @name is present, @name_len is the @name length in Unicode | |
330 | * characters. | |
331 | * | |
332 | * If @name is not present (NULL), we assume that the unnamed attribute is | |
333 | * being searched for. | |
334 | * | |
335 | * Finally, the resident attribute value @val is looked for, if present. If | |
336 | * @val is not present (NULL), @val_len is ignored. | |
337 | * | |
338 | * ntfs_attr_find() only searches the specified mft record and it ignores the | |
339 | * presence of an attribute list attribute (unless it is the one being searched | |
340 | * for, obviously). If you need to take attribute lists into consideration, | |
341 | * use ntfs_attr_lookup() instead (see below). This also means that you cannot | |
342 | * use ntfs_attr_find() to search for extent records of non-resident | |
343 | * attributes, as extents with lowest_vcn != 0 are usually described by the | |
344 | * attribute list attribute only. - Note that it is possible that the first | |
345 | * extent is only in the attribute list while the last extent is in the base | |
346 | * mft record, so do not rely on being able to find the first extent in the | |
347 | * base mft record. | |
348 | * | |
349 | * Warning: Never use @val when looking for attribute types which can be | |
350 | * non-resident as this most likely will result in a crash! | |
351 | */ | |
352 | static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, | |
353 | const u32 name_len, const IGNORE_CASE_BOOL ic, | |
354 | const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx) | |
355 | { | |
356 | ATTR_RECORD *a; | |
357 | ntfs_volume *vol = ctx->ntfs_ino->vol; | |
358 | ntfschar *upcase = vol->upcase; | |
359 | u32 upcase_len = vol->upcase_len; | |
360 | ||
361 | /* | |
362 | * Iterate over attributes in mft record starting at @ctx->attr, or the | |
363 | * attribute following that, if @ctx->is_first is TRUE. | |
364 | */ | |
365 | if (ctx->is_first) { | |
366 | a = ctx->attr; | |
367 | ctx->is_first = FALSE; | |
368 | } else | |
369 | a = (ATTR_RECORD*)((u8*)ctx->attr + | |
370 | le32_to_cpu(ctx->attr->length)); | |
371 | for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) { | |
372 | if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec + | |
373 | le32_to_cpu(ctx->mrec->bytes_allocated)) | |
374 | break; | |
375 | ctx->attr = a; | |
376 | if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) || | |
377 | a->type == AT_END)) | |
378 | return -ENOENT; | |
379 | if (unlikely(!a->length)) | |
380 | break; | |
381 | if (a->type != type) | |
382 | continue; | |
383 | /* | |
384 | * If @name is present, compare the two names. If @name is | |
385 | * missing, assume we want an unnamed attribute. | |
386 | */ | |
387 | if (!name) { | |
388 | /* The search failed if the found attribute is named. */ | |
389 | if (a->name_length) | |
390 | return -ENOENT; | |
391 | } else if (!ntfs_are_names_equal(name, name_len, | |
392 | (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)), | |
393 | a->name_length, ic, upcase, upcase_len)) { | |
394 | register int rc; | |
395 | ||
396 | rc = ntfs_collate_names(name, name_len, | |
397 | (ntfschar*)((u8*)a + | |
398 | le16_to_cpu(a->name_offset)), | |
399 | a->name_length, 1, IGNORE_CASE, | |
400 | upcase, upcase_len); | |
401 | /* | |
402 | * If @name collates before a->name, there is no | |
403 | * matching attribute. | |
404 | */ | |
405 | if (rc == -1) | |
406 | return -ENOENT; | |
407 | /* If the strings are not equal, continue search. */ | |
408 | if (rc) | |
409 | continue; | |
410 | rc = ntfs_collate_names(name, name_len, | |
411 | (ntfschar*)((u8*)a + | |
412 | le16_to_cpu(a->name_offset)), | |
413 | a->name_length, 1, CASE_SENSITIVE, | |
414 | upcase, upcase_len); | |
415 | if (rc == -1) | |
416 | return -ENOENT; | |
417 | if (rc) | |
418 | continue; | |
419 | } | |
420 | /* | |
421 | * The names match or @name not present and attribute is | |
422 | * unnamed. If no @val specified, we have found the attribute | |
423 | * and are done. | |
424 | */ | |
425 | if (!val) | |
426 | return 0; | |
427 | /* @val is present; compare values. */ | |
428 | else { | |
429 | register int rc; | |
430 | ||
431 | rc = memcmp(val, (u8*)a + le16_to_cpu( | |
432 | a->data.resident.value_offset), | |
433 | min_t(u32, val_len, le32_to_cpu( | |
434 | a->data.resident.value_length))); | |
435 | /* | |
436 | * If @val collates before the current attribute's | |
437 | * value, there is no matching attribute. | |
438 | */ | |
439 | if (!rc) { | |
440 | register u32 avl; | |
441 | ||
442 | avl = le32_to_cpu( | |
443 | a->data.resident.value_length); | |
444 | if (val_len == avl) | |
445 | return 0; | |
446 | if (val_len < avl) | |
447 | return -ENOENT; | |
448 | } else if (rc < 0) | |
449 | return -ENOENT; | |
450 | } | |
451 | } | |
452 | ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk."); | |
453 | NVolSetErrors(vol); | |
454 | return -EIO; | |
455 | } | |
456 | ||
457 | /** | |
458 | * load_attribute_list - load an attribute list into memory | |
459 | * @vol: ntfs volume from which to read | |
460 | * @runlist: runlist of the attribute list | |
461 | * @al_start: destination buffer | |
462 | * @size: size of the destination buffer in bytes | |
463 | * @initialized_size: initialized size of the attribute list | |
464 | * | |
465 | * Walk the runlist @runlist and load all clusters from it copying them into | |
466 | * the linear buffer @al. The maximum number of bytes copied to @al is @size | |
467 | * bytes. Note, @size does not need to be a multiple of the cluster size. If | |
468 | * @initialized_size is less than @size, the region in @al between | |
469 | * @initialized_size and @size will be zeroed and not read from disk. | |
470 | * | |
471 | * Return 0 on success or -errno on error. | |
472 | */ | |
473 | int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start, | |
474 | const s64 size, const s64 initialized_size) | |
475 | { | |
476 | LCN lcn; | |
477 | u8 *al = al_start; | |
478 | u8 *al_end = al + initialized_size; | |
479 | runlist_element *rl; | |
480 | struct buffer_head *bh; | |
481 | struct super_block *sb; | |
482 | unsigned long block_size; | |
483 | unsigned long block, max_block; | |
484 | int err = 0; | |
485 | unsigned char block_size_bits; | |
486 | ||
487 | ntfs_debug("Entering."); | |
488 | if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 || | |
489 | initialized_size > size) | |
490 | return -EINVAL; | |
491 | if (!initialized_size) { | |
492 | memset(al, 0, size); | |
493 | return 0; | |
494 | } | |
495 | sb = vol->sb; | |
496 | block_size = sb->s_blocksize; | |
497 | block_size_bits = sb->s_blocksize_bits; | |
498 | down_read(&runlist->lock); | |
499 | rl = runlist->rl; | |
500 | /* Read all clusters specified by the runlist one run at a time. */ | |
501 | while (rl->length) { | |
502 | lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn); | |
503 | ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.", | |
504 | (unsigned long long)rl->vcn, | |
505 | (unsigned long long)lcn); | |
506 | /* The attribute list cannot be sparse. */ | |
507 | if (lcn < 0) { | |
508 | ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed. Cannot " | |
509 | "read attribute list."); | |
510 | goto err_out; | |
511 | } | |
512 | block = lcn << vol->cluster_size_bits >> block_size_bits; | |
513 | /* Read the run from device in chunks of block_size bytes. */ | |
514 | max_block = block + (rl->length << vol->cluster_size_bits >> | |
515 | block_size_bits); | |
516 | ntfs_debug("max_block = 0x%lx.", max_block); | |
517 | do { | |
518 | ntfs_debug("Reading block = 0x%lx.", block); | |
519 | bh = sb_bread(sb, block); | |
520 | if (!bh) { | |
521 | ntfs_error(sb, "sb_bread() failed. Cannot " | |
522 | "read attribute list."); | |
523 | goto err_out; | |
524 | } | |
525 | if (al + block_size >= al_end) | |
526 | goto do_final; | |
527 | memcpy(al, bh->b_data, block_size); | |
528 | brelse(bh); | |
529 | al += block_size; | |
530 | } while (++block < max_block); | |
531 | rl++; | |
532 | } | |
533 | if (initialized_size < size) { | |
534 | initialize: | |
535 | memset(al_start + initialized_size, 0, size - initialized_size); | |
536 | } | |
537 | done: | |
538 | up_read(&runlist->lock); | |
539 | return err; | |
540 | do_final: | |
541 | if (al < al_end) { | |
542 | /* | |
543 | * Partial block. | |
544 | * | |
545 | * Note: The attribute list can be smaller than its allocation | |
546 | * by multiple clusters. This has been encountered by at least | |
547 | * two people running Windows XP, thus we cannot do any | |
548 | * truncation sanity checking here. (AIA) | |
549 | */ | |
550 | memcpy(al, bh->b_data, al_end - al); | |
551 | brelse(bh); | |
552 | if (initialized_size < size) | |
553 | goto initialize; | |
554 | goto done; | |
555 | } | |
556 | brelse(bh); | |
557 | /* Real overflow! */ | |
558 | ntfs_error(sb, "Attribute list buffer overflow. Read attribute list " | |
559 | "is truncated."); | |
560 | err_out: | |
561 | err = -EIO; | |
562 | goto done; | |
563 | } | |
564 | ||
565 | /** | |
566 | * ntfs_external_attr_find - find an attribute in the attribute list of an inode | |
567 | * @type: attribute type to find | |
568 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
569 | * @name_len: attribute name length (only needed if @name present) | |
570 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
571 | * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only) | |
572 | * @val: attribute value to find (optional, resident attributes only) | |
573 | * @val_len: attribute value length | |
574 | * @ctx: search context with mft record and attribute to search from | |
575 | * | |
576 | * You should not need to call this function directly. Use ntfs_attr_lookup() | |
577 | * instead. | |
578 | * | |
579 | * Find an attribute by searching the attribute list for the corresponding | |
580 | * attribute list entry. Having found the entry, map the mft record if the | |
581 | * attribute is in a different mft record/inode, ntfs_attr_find() the attribute | |
582 | * in there and return it. | |
583 | * | |
584 | * On first search @ctx->ntfs_ino must be the base mft record and @ctx must | |
585 | * have been obtained from a call to ntfs_attr_get_search_ctx(). On subsequent | |
586 | * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is | |
587 | * then the base inode). | |
588 | * | |
589 | * After finishing with the attribute/mft record you need to call | |
590 | * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any | |
591 | * mapped inodes, etc). | |
592 | * | |
593 | * If the attribute is found, ntfs_external_attr_find() returns 0 and | |
594 | * @ctx->attr will point to the found attribute. @ctx->mrec will point to the | |
595 | * mft record in which @ctx->attr is located and @ctx->al_entry will point to | |
596 | * the attribute list entry for the attribute. | |
597 | * | |
598 | * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and | |
599 | * @ctx->attr will point to the attribute in the base mft record before which | |
600 | * the attribute being searched for would need to be inserted if such an action | |
601 | * were to be desired. @ctx->mrec will point to the mft record in which | |
602 | * @ctx->attr is located and @ctx->al_entry will point to the attribute list | |
603 | * entry of the attribute before which the attribute being searched for would | |
604 | * need to be inserted if such an action were to be desired. | |
605 | * | |
606 | * Thus to insert the not found attribute, one wants to add the attribute to | |
607 | * @ctx->mrec (the base mft record) and if there is not enough space, the | |
608 | * attribute should be placed in a newly allocated extent mft record. The | |
609 | * attribute list entry for the inserted attribute should be inserted in the | |
610 | * attribute list attribute at @ctx->al_entry. | |
611 | * | |
612 | * On actual error, ntfs_external_attr_find() returns -EIO. In this case | |
613 | * @ctx->attr is undefined and in particular do not rely on it not changing. | |
614 | */ | |
615 | static int ntfs_external_attr_find(const ATTR_TYPE type, | |
616 | const ntfschar *name, const u32 name_len, | |
617 | const IGNORE_CASE_BOOL ic, const VCN lowest_vcn, | |
618 | const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx) | |
619 | { | |
620 | ntfs_inode *base_ni, *ni; | |
621 | ntfs_volume *vol; | |
622 | ATTR_LIST_ENTRY *al_entry, *next_al_entry; | |
623 | u8 *al_start, *al_end; | |
624 | ATTR_RECORD *a; | |
625 | ntfschar *al_name; | |
626 | u32 al_name_len; | |
627 | int err = 0; | |
628 | static const char *es = " Unmount and run chkdsk."; | |
629 | ||
630 | ni = ctx->ntfs_ino; | |
631 | base_ni = ctx->base_ntfs_ino; | |
632 | ntfs_debug("Entering for inode 0x%lx, type 0x%x.", ni->mft_no, type); | |
633 | if (!base_ni) { | |
634 | /* First call happens with the base mft record. */ | |
635 | base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino; | |
636 | ctx->base_mrec = ctx->mrec; | |
637 | } | |
638 | if (ni == base_ni) | |
639 | ctx->base_attr = ctx->attr; | |
640 | if (type == AT_END) | |
641 | goto not_found; | |
642 | vol = base_ni->vol; | |
643 | al_start = base_ni->attr_list; | |
644 | al_end = al_start + base_ni->attr_list_size; | |
645 | if (!ctx->al_entry) | |
646 | ctx->al_entry = (ATTR_LIST_ENTRY*)al_start; | |
647 | /* | |
648 | * Iterate over entries in attribute list starting at @ctx->al_entry, | |
649 | * or the entry following that, if @ctx->is_first is TRUE. | |
650 | */ | |
651 | if (ctx->is_first) { | |
652 | al_entry = ctx->al_entry; | |
653 | ctx->is_first = FALSE; | |
654 | } else | |
655 | al_entry = (ATTR_LIST_ENTRY*)((u8*)ctx->al_entry + | |
656 | le16_to_cpu(ctx->al_entry->length)); | |
657 | for (;; al_entry = next_al_entry) { | |
658 | /* Out of bounds check. */ | |
659 | if ((u8*)al_entry < base_ni->attr_list || | |
660 | (u8*)al_entry > al_end) | |
661 | break; /* Inode is corrupt. */ | |
662 | ctx->al_entry = al_entry; | |
663 | /* Catch the end of the attribute list. */ | |
664 | if ((u8*)al_entry == al_end) | |
665 | goto not_found; | |
666 | if (!al_entry->length) | |
667 | break; | |
668 | if ((u8*)al_entry + 6 > al_end || (u8*)al_entry + | |
669 | le16_to_cpu(al_entry->length) > al_end) | |
670 | break; | |
671 | next_al_entry = (ATTR_LIST_ENTRY*)((u8*)al_entry + | |
672 | le16_to_cpu(al_entry->length)); | |
673 | if (le32_to_cpu(al_entry->type) > le32_to_cpu(type)) | |
674 | goto not_found; | |
675 | if (type != al_entry->type) | |
676 | continue; | |
677 | /* | |
678 | * If @name is present, compare the two names. If @name is | |
679 | * missing, assume we want an unnamed attribute. | |
680 | */ | |
681 | al_name_len = al_entry->name_length; | |
682 | al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset); | |
683 | if (!name) { | |
684 | if (al_name_len) | |
685 | goto not_found; | |
686 | } else if (!ntfs_are_names_equal(al_name, al_name_len, name, | |
687 | name_len, ic, vol->upcase, vol->upcase_len)) { | |
688 | register int rc; | |
689 | ||
690 | rc = ntfs_collate_names(name, name_len, al_name, | |
691 | al_name_len, 1, IGNORE_CASE, | |
692 | vol->upcase, vol->upcase_len); | |
693 | /* | |
694 | * If @name collates before al_name, there is no | |
695 | * matching attribute. | |
696 | */ | |
697 | if (rc == -1) | |
698 | goto not_found; | |
699 | /* If the strings are not equal, continue search. */ | |
700 | if (rc) | |
701 | continue; | |
702 | /* | |
703 | * FIXME: Reverse engineering showed 0, IGNORE_CASE but | |
704 | * that is inconsistent with ntfs_attr_find(). The | |
705 | * subsequent rc checks were also different. Perhaps I | |
706 | * made a mistake in one of the two. Need to recheck | |
707 | * which is correct or at least see what is going on... | |
708 | * (AIA) | |
709 | */ | |
710 | rc = ntfs_collate_names(name, name_len, al_name, | |
711 | al_name_len, 1, CASE_SENSITIVE, | |
712 | vol->upcase, vol->upcase_len); | |
713 | if (rc == -1) | |
714 | goto not_found; | |
715 | if (rc) | |
716 | continue; | |
717 | } | |
718 | /* | |
719 | * The names match or @name not present and attribute is | |
720 | * unnamed. Now check @lowest_vcn. Continue search if the | |
721 | * next attribute list entry still fits @lowest_vcn. Otherwise | |
722 | * we have reached the right one or the search has failed. | |
723 | */ | |
724 | if (lowest_vcn && (u8*)next_al_entry >= al_start && | |
725 | (u8*)next_al_entry + 6 < al_end && | |
726 | (u8*)next_al_entry + le16_to_cpu( | |
727 | next_al_entry->length) <= al_end && | |
728 | sle64_to_cpu(next_al_entry->lowest_vcn) <= | |
729 | lowest_vcn && | |
730 | next_al_entry->type == al_entry->type && | |
731 | next_al_entry->name_length == al_name_len && | |
732 | ntfs_are_names_equal((ntfschar*)((u8*) | |
733 | next_al_entry + | |
734 | next_al_entry->name_offset), | |
735 | next_al_entry->name_length, | |
736 | al_name, al_name_len, CASE_SENSITIVE, | |
737 | vol->upcase, vol->upcase_len)) | |
738 | continue; | |
739 | if (MREF_LE(al_entry->mft_reference) == ni->mft_no) { | |
740 | if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) { | |
741 | ntfs_error(vol->sb, "Found stale mft " | |
742 | "reference in attribute list " | |
743 | "of base inode 0x%lx.%s", | |
744 | base_ni->mft_no, es); | |
745 | err = -EIO; | |
746 | break; | |
747 | } | |
748 | } else { /* Mft references do not match. */ | |
749 | /* If there is a mapped record unmap it first. */ | |
750 | if (ni != base_ni) | |
751 | unmap_extent_mft_record(ni); | |
752 | /* Do we want the base record back? */ | |
753 | if (MREF_LE(al_entry->mft_reference) == | |
754 | base_ni->mft_no) { | |
755 | ni = ctx->ntfs_ino = base_ni; | |
756 | ctx->mrec = ctx->base_mrec; | |
757 | } else { | |
758 | /* We want an extent record. */ | |
759 | ctx->mrec = map_extent_mft_record(base_ni, | |
760 | le64_to_cpu( | |
761 | al_entry->mft_reference), &ni); | |
762 | if (IS_ERR(ctx->mrec)) { | |
763 | ntfs_error(vol->sb, "Failed to map " | |
764 | "extent mft record " | |
765 | "0x%lx of base inode " | |
766 | "0x%lx.%s", | |
767 | MREF_LE(al_entry-> | |
768 | mft_reference), | |
769 | base_ni->mft_no, es); | |
770 | err = PTR_ERR(ctx->mrec); | |
771 | if (err == -ENOENT) | |
772 | err = -EIO; | |
773 | /* Cause @ctx to be sanitized below. */ | |
774 | ni = NULL; | |
775 | break; | |
776 | } | |
777 | ctx->ntfs_ino = ni; | |
778 | } | |
779 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
780 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
781 | } | |
782 | /* | |
783 | * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the | |
784 | * mft record containing the attribute represented by the | |
785 | * current al_entry. | |
786 | */ | |
787 | /* | |
788 | * We could call into ntfs_attr_find() to find the right | |
789 | * attribute in this mft record but this would be less | |
790 | * efficient and not quite accurate as ntfs_attr_find() ignores | |
791 | * the attribute instance numbers for example which become | |
792 | * important when one plays with attribute lists. Also, | |
793 | * because a proper match has been found in the attribute list | |
794 | * entry above, the comparison can now be optimized. So it is | |
795 | * worth re-implementing a simplified ntfs_attr_find() here. | |
796 | */ | |
797 | a = ctx->attr; | |
798 | /* | |
799 | * Use a manual loop so we can still use break and continue | |
800 | * with the same meanings as above. | |
801 | */ | |
802 | do_next_attr_loop: | |
803 | if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec + | |
804 | le32_to_cpu(ctx->mrec->bytes_allocated)) | |
805 | break; | |
806 | if (a->type == AT_END) | |
807 | continue; | |
808 | if (!a->length) | |
809 | break; | |
810 | if (al_entry->instance != a->instance) | |
811 | goto do_next_attr; | |
812 | /* | |
813 | * If the type and/or the name are mismatched between the | |
814 | * attribute list entry and the attribute record, there is | |
815 | * corruption so we break and return error EIO. | |
816 | */ | |
817 | if (al_entry->type != a->type) | |
818 | break; | |
819 | if (!ntfs_are_names_equal((ntfschar*)((u8*)a + | |
820 | le16_to_cpu(a->name_offset)), a->name_length, | |
821 | al_name, al_name_len, CASE_SENSITIVE, | |
822 | vol->upcase, vol->upcase_len)) | |
823 | break; | |
824 | ctx->attr = a; | |
825 | /* | |
826 | * If no @val specified or @val specified and it matches, we | |
827 | * have found it! | |
828 | */ | |
829 | if (!val || (!a->non_resident && le32_to_cpu( | |
830 | a->data.resident.value_length) == val_len && | |
831 | !memcmp((u8*)a + | |
832 | le16_to_cpu(a->data.resident.value_offset), | |
833 | val, val_len))) { | |
834 | ntfs_debug("Done, found."); | |
835 | return 0; | |
836 | } | |
837 | do_next_attr: | |
838 | /* Proceed to the next attribute in the current mft record. */ | |
839 | a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length)); | |
840 | goto do_next_attr_loop; | |
841 | } | |
842 | if (!err) { | |
843 | ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt " | |
844 | "attribute list attribute.%s", base_ni->mft_no, | |
845 | es); | |
846 | err = -EIO; | |
847 | } | |
848 | if (ni != base_ni) { | |
849 | if (ni) | |
850 | unmap_extent_mft_record(ni); | |
851 | ctx->ntfs_ino = base_ni; | |
852 | ctx->mrec = ctx->base_mrec; | |
853 | ctx->attr = ctx->base_attr; | |
854 | } | |
855 | if (err != -ENOMEM) | |
856 | NVolSetErrors(vol); | |
857 | return err; | |
858 | not_found: | |
859 | /* | |
860 | * If we were looking for AT_END, we reset the search context @ctx and | |
861 | * use ntfs_attr_find() to seek to the end of the base mft record. | |
862 | */ | |
863 | if (type == AT_END) { | |
864 | ntfs_attr_reinit_search_ctx(ctx); | |
865 | return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len, | |
866 | ctx); | |
867 | } | |
868 | /* | |
869 | * The attribute was not found. Before we return, we want to ensure | |
870 | * @ctx->mrec and @ctx->attr indicate the position at which the | |
871 | * attribute should be inserted in the base mft record. Since we also | |
872 | * want to preserve @ctx->al_entry we cannot reinitialize the search | |
873 | * context using ntfs_attr_reinit_search_ctx() as this would set | |
874 | * @ctx->al_entry to NULL. Thus we do the necessary bits manually (see | |
875 | * ntfs_attr_init_search_ctx() below). Note, we _only_ preserve | |
876 | * @ctx->al_entry as the remaining fields (base_*) are identical to | |
877 | * their non base_ counterparts and we cannot set @ctx->base_attr | |
878 | * correctly yet as we do not know what @ctx->attr will be set to by | |
879 | * the call to ntfs_attr_find() below. | |
880 | */ | |
881 | if (ni != base_ni) | |
882 | unmap_extent_mft_record(ni); | |
883 | ctx->mrec = ctx->base_mrec; | |
884 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
885 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
886 | ctx->is_first = TRUE; | |
887 | ctx->ntfs_ino = base_ni; | |
888 | ctx->base_ntfs_ino = NULL; | |
889 | ctx->base_mrec = NULL; | |
890 | ctx->base_attr = NULL; | |
891 | /* | |
892 | * In case there are multiple matches in the base mft record, need to | |
893 | * keep enumerating until we get an attribute not found response (or | |
894 | * another error), otherwise we would keep returning the same attribute | |
895 | * over and over again and all programs using us for enumeration would | |
896 | * lock up in a tight loop. | |
897 | */ | |
898 | do { | |
899 | err = ntfs_attr_find(type, name, name_len, ic, val, val_len, | |
900 | ctx); | |
901 | } while (!err); | |
902 | ntfs_debug("Done, not found."); | |
903 | return err; | |
904 | } | |
905 | ||
906 | /** | |
907 | * ntfs_attr_lookup - find an attribute in an ntfs inode | |
908 | * @type: attribute type to find | |
909 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
910 | * @name_len: attribute name length (only needed if @name present) | |
911 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
912 | * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only) | |
913 | * @val: attribute value to find (optional, resident attributes only) | |
914 | * @val_len: attribute value length | |
915 | * @ctx: search context with mft record and attribute to search from | |
916 | * | |
917 | * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must | |
918 | * be the base mft record and @ctx must have been obtained from a call to | |
919 | * ntfs_attr_get_search_ctx(). | |
920 | * | |
921 | * This function transparently handles attribute lists and @ctx is used to | |
922 | * continue searches where they were left off at. | |
923 | * | |
924 | * After finishing with the attribute/mft record you need to call | |
925 | * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any | |
926 | * mapped inodes, etc). | |
927 | * | |
928 | * Return 0 if the search was successful and -errno if not. | |
929 | * | |
930 | * When 0, @ctx->attr is the found attribute and it is in mft record | |
931 | * @ctx->mrec. If an attribute list attribute is present, @ctx->al_entry is | |
932 | * the attribute list entry of the found attribute. | |
933 | * | |
934 | * When -ENOENT, @ctx->attr is the attribute which collates just after the | |
935 | * attribute being searched for, i.e. if one wants to add the attribute to the | |
936 | * mft record this is the correct place to insert it into. If an attribute | |
937 | * list attribute is present, @ctx->al_entry is the attribute list entry which | |
938 | * collates just after the attribute list entry of the attribute being searched | |
939 | * for, i.e. if one wants to add the attribute to the mft record this is the | |
940 | * correct place to insert its attribute list entry into. | |
941 | * | |
942 | * When -errno != -ENOENT, an error occured during the lookup. @ctx->attr is | |
943 | * then undefined and in particular you should not rely on it not changing. | |
944 | */ | |
945 | int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name, | |
946 | const u32 name_len, const IGNORE_CASE_BOOL ic, | |
947 | const VCN lowest_vcn, const u8 *val, const u32 val_len, | |
948 | ntfs_attr_search_ctx *ctx) | |
949 | { | |
950 | ntfs_inode *base_ni; | |
951 | ||
952 | ntfs_debug("Entering."); | |
953 | if (ctx->base_ntfs_ino) | |
954 | base_ni = ctx->base_ntfs_ino; | |
955 | else | |
956 | base_ni = ctx->ntfs_ino; | |
957 | /* Sanity check, just for debugging really. */ | |
958 | BUG_ON(!base_ni); | |
959 | if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST) | |
960 | return ntfs_attr_find(type, name, name_len, ic, val, val_len, | |
961 | ctx); | |
962 | return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn, | |
963 | val, val_len, ctx); | |
964 | } | |
965 | ||
966 | /** | |
967 | * ntfs_attr_init_search_ctx - initialize an attribute search context | |
968 | * @ctx: attribute search context to initialize | |
969 | * @ni: ntfs inode with which to initialize the search context | |
970 | * @mrec: mft record with which to initialize the search context | |
971 | * | |
972 | * Initialize the attribute search context @ctx with @ni and @mrec. | |
973 | */ | |
974 | static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx, | |
975 | ntfs_inode *ni, MFT_RECORD *mrec) | |
976 | { | |
977 | ctx->mrec = mrec; | |
978 | /* Sanity checks are performed elsewhere. */ | |
979 | ctx->attr = (ATTR_RECORD*)((u8*)mrec + le16_to_cpu(mrec->attrs_offset)); | |
980 | ctx->is_first = TRUE; | |
981 | ctx->ntfs_ino = ni; | |
982 | ctx->al_entry = NULL; | |
983 | ctx->base_ntfs_ino = NULL; | |
984 | ctx->base_mrec = NULL; | |
985 | ctx->base_attr = NULL; | |
986 | } | |
987 | ||
988 | /** | |
989 | * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context | |
990 | * @ctx: attribute search context to reinitialize | |
991 | * | |
992 | * Reinitialize the attribute search context @ctx, unmapping an associated | |
993 | * extent mft record if present, and initialize the search context again. | |
994 | * | |
995 | * This is used when a search for a new attribute is being started to reset | |
996 | * the search context to the beginning. | |
997 | */ | |
998 | void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx) | |
999 | { | |
1000 | if (likely(!ctx->base_ntfs_ino)) { | |
1001 | /* No attribute list. */ | |
1002 | ctx->is_first = TRUE; | |
1003 | /* Sanity checks are performed elsewhere. */ | |
1004 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
1005 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
1006 | /* | |
1007 | * This needs resetting due to ntfs_external_attr_find() which | |
1008 | * can leave it set despite having zeroed ctx->base_ntfs_ino. | |
1009 | */ | |
1010 | ctx->al_entry = NULL; | |
1011 | return; | |
1012 | } /* Attribute list. */ | |
1013 | if (ctx->ntfs_ino != ctx->base_ntfs_ino) | |
1014 | unmap_extent_mft_record(ctx->ntfs_ino); | |
1015 | ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec); | |
1016 | return; | |
1017 | } | |
1018 | ||
1019 | /** | |
1020 | * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context | |
1021 | * @ni: ntfs inode with which to initialize the search context | |
1022 | * @mrec: mft record with which to initialize the search context | |
1023 | * | |
1024 | * Allocate a new attribute search context, initialize it with @ni and @mrec, | |
1025 | * and return it. Return NULL if allocation failed. | |
1026 | */ | |
1027 | ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec) | |
1028 | { | |
1029 | ntfs_attr_search_ctx *ctx; | |
1030 | ||
1031 | ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, SLAB_NOFS); | |
1032 | if (ctx) | |
1033 | ntfs_attr_init_search_ctx(ctx, ni, mrec); | |
1034 | return ctx; | |
1035 | } | |
1036 | ||
1037 | /** | |
1038 | * ntfs_attr_put_search_ctx - release an attribute search context | |
1039 | * @ctx: attribute search context to free | |
1040 | * | |
1041 | * Release the attribute search context @ctx, unmapping an associated extent | |
1042 | * mft record if present. | |
1043 | */ | |
1044 | void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx) | |
1045 | { | |
1046 | if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino) | |
1047 | unmap_extent_mft_record(ctx->ntfs_ino); | |
1048 | kmem_cache_free(ntfs_attr_ctx_cache, ctx); | |
1049 | return; | |
1050 | } | |
1051 | ||
1052 | /** | |
1053 | * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file | |
1054 | * @vol: ntfs volume to which the attribute belongs | |
1055 | * @type: attribute type which to find | |
1056 | * | |
1057 | * Search for the attribute definition record corresponding to the attribute | |
1058 | * @type in the $AttrDef system file. | |
1059 | * | |
1060 | * Return the attribute type definition record if found and NULL if not found. | |
1061 | */ | |
1062 | static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol, | |
1063 | const ATTR_TYPE type) | |
1064 | { | |
1065 | ATTR_DEF *ad; | |
1066 | ||
1067 | BUG_ON(!vol->attrdef); | |
1068 | BUG_ON(!type); | |
1069 | for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef < | |
1070 | vol->attrdef_size && ad->type; ++ad) { | |
1071 | /* We have not found it yet, carry on searching. */ | |
1072 | if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type))) | |
1073 | continue; | |
1074 | /* We found the attribute; return it. */ | |
1075 | if (likely(ad->type == type)) | |
1076 | return ad; | |
1077 | /* We have gone too far already. No point in continuing. */ | |
1078 | break; | |
1079 | } | |
1080 | /* Attribute not found. */ | |
1081 | ntfs_debug("Attribute type 0x%x not found in $AttrDef.", | |
1082 | le32_to_cpu(type)); | |
1083 | return NULL; | |
1084 | } | |
1085 | ||
1086 | /** | |
1087 | * ntfs_attr_size_bounds_check - check a size of an attribute type for validity | |
1088 | * @vol: ntfs volume to which the attribute belongs | |
1089 | * @type: attribute type which to check | |
1090 | * @size: size which to check | |
1091 | * | |
1092 | * Check whether the @size in bytes is valid for an attribute of @type on the | |
1093 | * ntfs volume @vol. This information is obtained from $AttrDef system file. | |
1094 | * | |
1095 | * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not | |
1096 | * listed in $AttrDef. | |
1097 | */ | |
1098 | int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type, | |
1099 | const s64 size) | |
1100 | { | |
1101 | ATTR_DEF *ad; | |
1102 | ||
1103 | BUG_ON(size < 0); | |
1104 | /* | |
1105 | * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not | |
1106 | * listed in $AttrDef. | |
1107 | */ | |
1108 | if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024)) | |
1109 | return -ERANGE; | |
1110 | /* Get the $AttrDef entry for the attribute @type. */ | |
1111 | ad = ntfs_attr_find_in_attrdef(vol, type); | |
1112 | if (unlikely(!ad)) | |
1113 | return -ENOENT; | |
1114 | /* Do the bounds check. */ | |
1115 | if (((sle64_to_cpu(ad->min_size) > 0) && | |
1116 | size < sle64_to_cpu(ad->min_size)) || | |
1117 | ((sle64_to_cpu(ad->max_size) > 0) && size > | |
1118 | sle64_to_cpu(ad->max_size))) | |
1119 | return -ERANGE; | |
1120 | return 0; | |
1121 | } | |
1122 | ||
1123 | /** | |
1124 | * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident | |
1125 | * @vol: ntfs volume to which the attribute belongs | |
1126 | * @type: attribute type which to check | |
1127 | * | |
1128 | * Check whether the attribute of @type on the ntfs volume @vol is allowed to | |
1129 | * be non-resident. This information is obtained from $AttrDef system file. | |
1130 | * | |
1131 | * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, or | |
1132 | * -ENOENT if the attribute is not listed in $AttrDef. | |
1133 | */ | |
1134 | int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type) | |
1135 | { | |
1136 | ATTR_DEF *ad; | |
1137 | ||
1138 | /* | |
7e693073 AA |
1139 | * $DATA and $EA are always allowed to be non-resident even if $AttrDef |
1140 | * does not specify this in the flags of the $DATA attribute definition | |
1141 | * record. | |
1da177e4 | 1142 | */ |
7e693073 | 1143 | if (type == AT_DATA || type == AT_EA) |
1da177e4 LT |
1144 | return 0; |
1145 | /* Find the attribute definition record in $AttrDef. */ | |
1146 | ad = ntfs_attr_find_in_attrdef(vol, type); | |
1147 | if (unlikely(!ad)) | |
1148 | return -ENOENT; | |
1149 | /* Check the flags and return the result. */ | |
1150 | if (ad->flags & CAN_BE_NON_RESIDENT) | |
1151 | return 0; | |
1152 | return -EPERM; | |
1153 | } | |
1154 | ||
1155 | /** | |
1156 | * ntfs_attr_can_be_resident - check if an attribute can be resident | |
1157 | * @vol: ntfs volume to which the attribute belongs | |
1158 | * @type: attribute type which to check | |
1159 | * | |
1160 | * Check whether the attribute of @type on the ntfs volume @vol is allowed to | |
1161 | * be resident. This information is derived from our ntfs knowledge and may | |
1162 | * not be completely accurate, especially when user defined attributes are | |
1163 | * present. Basically we allow everything to be resident except for index | |
1164 | * allocation and $EA attributes. | |
1165 | * | |
1166 | * Return 0 if the attribute is allowed to be non-resident and -EPERM if not. | |
1167 | * | |
1168 | * Warning: In the system file $MFT the attribute $Bitmap must be non-resident | |
1169 | * otherwise windows will not boot (blue screen of death)! We cannot | |
1170 | * check for this here as we do not know which inode's $Bitmap is | |
1171 | * being asked about so the caller needs to special case this. | |
1172 | */ | |
1173 | int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type) | |
1174 | { | |
1175 | if (type != AT_INDEX_ALLOCATION && type != AT_EA) | |
1176 | return 0; | |
1177 | return -EPERM; | |
1178 | } | |
1179 | ||
1180 | /** | |
1181 | * ntfs_attr_record_resize - resize an attribute record | |
1182 | * @m: mft record containing attribute record | |
1183 | * @a: attribute record to resize | |
1184 | * @new_size: new size in bytes to which to resize the attribute record @a | |
1185 | * | |
1186 | * Resize the attribute record @a, i.e. the resident part of the attribute, in | |
1187 | * the mft record @m to @new_size bytes. | |
1188 | * | |
1189 | * Return 0 on success and -errno on error. The following error codes are | |
1190 | * defined: | |
1191 | * -ENOSPC - Not enough space in the mft record @m to perform the resize. | |
1192 | * | |
1193 | * Note: On error, no modifications have been performed whatsoever. | |
1194 | * | |
1195 | * Warning: If you make a record smaller without having copied all the data you | |
1196 | * are interested in the data may be overwritten. | |
1197 | */ | |
1198 | int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size) | |
1199 | { | |
1200 | ntfs_debug("Entering for new_size %u.", new_size); | |
1201 | /* Align to 8 bytes if it is not already done. */ | |
1202 | if (new_size & 7) | |
1203 | new_size = (new_size + 7) & ~7; | |
1204 | /* If the actual attribute length has changed, move things around. */ | |
1205 | if (new_size != le32_to_cpu(a->length)) { | |
1206 | u32 new_muse = le32_to_cpu(m->bytes_in_use) - | |
1207 | le32_to_cpu(a->length) + new_size; | |
1208 | /* Not enough space in this mft record. */ | |
1209 | if (new_muse > le32_to_cpu(m->bytes_allocated)) | |
1210 | return -ENOSPC; | |
1211 | /* Move attributes following @a to their new location. */ | |
1212 | memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length), | |
1213 | le32_to_cpu(m->bytes_in_use) - ((u8*)a - | |
1214 | (u8*)m) - le32_to_cpu(a->length)); | |
1215 | /* Adjust @m to reflect the change in used space. */ | |
1216 | m->bytes_in_use = cpu_to_le32(new_muse); | |
1217 | /* Adjust @a to reflect the new size. */ | |
1218 | if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length)) | |
1219 | a->length = cpu_to_le32(new_size); | |
1220 | } | |
1221 | return 0; | |
1222 | } | |
1223 | ||
1224 | /** | |
1225 | * ntfs_attr_set - fill (a part of) an attribute with a byte | |
1226 | * @ni: ntfs inode describing the attribute to fill | |
1227 | * @ofs: offset inside the attribute at which to start to fill | |
1228 | * @cnt: number of bytes to fill | |
1229 | * @val: the unsigned 8-bit value with which to fill the attribute | |
1230 | * | |
1231 | * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at | |
1232 | * byte offset @ofs inside the attribute with the constant byte @val. | |
1233 | * | |
1234 | * This function is effectively like memset() applied to an ntfs attribute. | |
da28438c AA |
1235 | * Note thie function actually only operates on the page cache pages belonging |
1236 | * to the ntfs attribute and it marks them dirty after doing the memset(). | |
1237 | * Thus it relies on the vm dirty page write code paths to cause the modified | |
1238 | * pages to be written to the mft record/disk. | |
1da177e4 LT |
1239 | * |
1240 | * Return 0 on success and -errno on error. An error code of -ESPIPE means | |
1241 | * that @ofs + @cnt were outside the end of the attribute and no write was | |
1242 | * performed. | |
1243 | */ | |
1244 | int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val) | |
1245 | { | |
1246 | ntfs_volume *vol = ni->vol; | |
1247 | struct address_space *mapping; | |
1248 | struct page *page; | |
1249 | u8 *kaddr; | |
1250 | pgoff_t idx, end; | |
1251 | unsigned int start_ofs, end_ofs, size; | |
1252 | ||
1253 | ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.", | |
1254 | (long long)ofs, (long long)cnt, val); | |
1255 | BUG_ON(ofs < 0); | |
1256 | BUG_ON(cnt < 0); | |
1257 | if (!cnt) | |
1258 | goto done; | |
1259 | mapping = VFS_I(ni)->i_mapping; | |
1260 | /* Work out the starting index and page offset. */ | |
1261 | idx = ofs >> PAGE_CACHE_SHIFT; | |
1262 | start_ofs = ofs & ~PAGE_CACHE_MASK; | |
1263 | /* Work out the ending index and page offset. */ | |
1264 | end = ofs + cnt; | |
1265 | end_ofs = end & ~PAGE_CACHE_MASK; | |
1266 | /* If the end is outside the inode size return -ESPIPE. */ | |
da28438c | 1267 | if (unlikely(end > i_size_read(VFS_I(ni)))) { |
1da177e4 LT |
1268 | ntfs_error(vol->sb, "Request exceeds end of attribute."); |
1269 | return -ESPIPE; | |
1270 | } | |
1271 | end >>= PAGE_CACHE_SHIFT; | |
1272 | /* If there is a first partial page, need to do it the slow way. */ | |
1273 | if (start_ofs) { | |
1274 | page = read_cache_page(mapping, idx, | |
1275 | (filler_t*)mapping->a_ops->readpage, NULL); | |
1276 | if (IS_ERR(page)) { | |
1277 | ntfs_error(vol->sb, "Failed to read first partial " | |
1278 | "page (sync error, index 0x%lx).", idx); | |
1279 | return PTR_ERR(page); | |
1280 | } | |
1281 | wait_on_page_locked(page); | |
1282 | if (unlikely(!PageUptodate(page))) { | |
1283 | ntfs_error(vol->sb, "Failed to read first partial page " | |
1284 | "(async error, index 0x%lx).", idx); | |
1285 | page_cache_release(page); | |
1286 | return PTR_ERR(page); | |
1287 | } | |
1288 | /* | |
1289 | * If the last page is the same as the first page, need to | |
1290 | * limit the write to the end offset. | |
1291 | */ | |
1292 | size = PAGE_CACHE_SIZE; | |
1293 | if (idx == end) | |
1294 | size = end_ofs; | |
1295 | kaddr = kmap_atomic(page, KM_USER0); | |
1296 | memset(kaddr + start_ofs, val, size - start_ofs); | |
1297 | flush_dcache_page(page); | |
1298 | kunmap_atomic(kaddr, KM_USER0); | |
1299 | set_page_dirty(page); | |
1300 | page_cache_release(page); | |
1301 | if (idx == end) | |
1302 | goto done; | |
1303 | idx++; | |
1304 | } | |
1305 | /* Do the whole pages the fast way. */ | |
1306 | for (; idx < end; idx++) { | |
1307 | /* Find or create the current page. (The page is locked.) */ | |
1308 | page = grab_cache_page(mapping, idx); | |
1309 | if (unlikely(!page)) { | |
1310 | ntfs_error(vol->sb, "Insufficient memory to grab " | |
1311 | "page (index 0x%lx).", idx); | |
1312 | return -ENOMEM; | |
1313 | } | |
1314 | kaddr = kmap_atomic(page, KM_USER0); | |
1315 | memset(kaddr, val, PAGE_CACHE_SIZE); | |
1316 | flush_dcache_page(page); | |
1317 | kunmap_atomic(kaddr, KM_USER0); | |
1318 | /* | |
1319 | * If the page has buffers, mark them uptodate since buffer | |
1320 | * state and not page state is definitive in 2.6 kernels. | |
1321 | */ | |
1322 | if (page_has_buffers(page)) { | |
1323 | struct buffer_head *bh, *head; | |
1324 | ||
1325 | bh = head = page_buffers(page); | |
1326 | do { | |
1327 | set_buffer_uptodate(bh); | |
1328 | } while ((bh = bh->b_this_page) != head); | |
1329 | } | |
1330 | /* Now that buffers are uptodate, set the page uptodate, too. */ | |
1331 | SetPageUptodate(page); | |
1332 | /* | |
1333 | * Set the page and all its buffers dirty and mark the inode | |
1334 | * dirty, too. The VM will write the page later on. | |
1335 | */ | |
1336 | set_page_dirty(page); | |
1337 | /* Finally unlock and release the page. */ | |
1338 | unlock_page(page); | |
1339 | page_cache_release(page); | |
1340 | } | |
1341 | /* If there is a last partial page, need to do it the slow way. */ | |
1342 | if (end_ofs) { | |
1343 | page = read_cache_page(mapping, idx, | |
1344 | (filler_t*)mapping->a_ops->readpage, NULL); | |
1345 | if (IS_ERR(page)) { | |
1346 | ntfs_error(vol->sb, "Failed to read last partial page " | |
1347 | "(sync error, index 0x%lx).", idx); | |
1348 | return PTR_ERR(page); | |
1349 | } | |
1350 | wait_on_page_locked(page); | |
1351 | if (unlikely(!PageUptodate(page))) { | |
1352 | ntfs_error(vol->sb, "Failed to read last partial page " | |
1353 | "(async error, index 0x%lx).", idx); | |
1354 | page_cache_release(page); | |
1355 | return PTR_ERR(page); | |
1356 | } | |
1357 | kaddr = kmap_atomic(page, KM_USER0); | |
1358 | memset(kaddr, val, end_ofs); | |
1359 | flush_dcache_page(page); | |
1360 | kunmap_atomic(kaddr, KM_USER0); | |
1361 | set_page_dirty(page); | |
1362 | page_cache_release(page); | |
1363 | } | |
1364 | done: | |
1365 | ntfs_debug("Done."); | |
1366 | return 0; | |
1367 | } |