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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" | |
2bfb4fff AA |
28 | #include "lcnalloc.h" |
29 | #include "malloc.h" | |
1da177e4 LT |
30 | #include "mft.h" |
31 | #include "ntfs.h" | |
32 | #include "types.h" | |
33 | ||
34 | /** | |
b6ad6c52 | 35 | * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode |
1da177e4 LT |
36 | * @ni: ntfs inode for which to map (part of) a runlist |
37 | * @vcn: map runlist part containing this vcn | |
38 | * | |
39 | * Map the part of a runlist containing the @vcn of the ntfs inode @ni. | |
40 | * | |
41 | * Return 0 on success and -errno on error. | |
42 | * | |
b6ad6c52 AA |
43 | * Locking: - The runlist must be locked for writing. |
44 | * - This function modifies the runlist. | |
1da177e4 | 45 | */ |
b6ad6c52 | 46 | int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) |
1da177e4 LT |
47 | { |
48 | ntfs_inode *base_ni; | |
1da177e4 | 49 | MFT_RECORD *mrec; |
b6ad6c52 AA |
50 | ntfs_attr_search_ctx *ctx; |
51 | runlist_element *rl; | |
1da177e4 LT |
52 | int err = 0; |
53 | ||
54 | ntfs_debug("Mapping runlist part containing vcn 0x%llx.", | |
55 | (unsigned long long)vcn); | |
1da177e4 LT |
56 | if (!NInoAttr(ni)) |
57 | base_ni = ni; | |
58 | else | |
59 | base_ni = ni->ext.base_ntfs_ino; | |
1da177e4 LT |
60 | mrec = map_mft_record(base_ni); |
61 | if (IS_ERR(mrec)) | |
62 | return PTR_ERR(mrec); | |
63 | ctx = ntfs_attr_get_search_ctx(base_ni, mrec); | |
64 | if (unlikely(!ctx)) { | |
65 | err = -ENOMEM; | |
66 | goto err_out; | |
67 | } | |
68 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
69 | CASE_SENSITIVE, vcn, NULL, 0, ctx); | |
b6ad6c52 | 70 | if (likely(!err)) { |
1da177e4 LT |
71 | rl = ntfs_mapping_pairs_decompress(ni->vol, ctx->attr, |
72 | ni->runlist.rl); | |
73 | if (IS_ERR(rl)) | |
74 | err = PTR_ERR(rl); | |
75 | else | |
76 | ni->runlist.rl = rl; | |
77 | } | |
1da177e4 LT |
78 | ntfs_attr_put_search_ctx(ctx); |
79 | err_out: | |
80 | unmap_mft_record(base_ni); | |
81 | return err; | |
82 | } | |
83 | ||
84 | /** | |
b6ad6c52 AA |
85 | * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode |
86 | * @ni: ntfs inode for which to map (part of) a runlist | |
87 | * @vcn: map runlist part containing this vcn | |
88 | * | |
89 | * Map the part of a runlist containing the @vcn of the ntfs inode @ni. | |
90 | * | |
91 | * Return 0 on success and -errno on error. | |
92 | * | |
93 | * Locking: - The runlist must be unlocked on entry and is unlocked on return. | |
94 | * - This function takes the runlist lock for writing and modifies the | |
95 | * runlist. | |
96 | */ | |
97 | int ntfs_map_runlist(ntfs_inode *ni, VCN vcn) | |
98 | { | |
99 | int err = 0; | |
100 | ||
101 | down_write(&ni->runlist.lock); | |
102 | /* Make sure someone else didn't do the work while we were sleeping. */ | |
103 | if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <= | |
104 | LCN_RL_NOT_MAPPED)) | |
105 | err = ntfs_map_runlist_nolock(ni, vcn); | |
106 | up_write(&ni->runlist.lock); | |
107 | return err; | |
108 | } | |
109 | ||
271849a9 AA |
110 | /** |
111 | * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode | |
112 | * @ni: ntfs inode of the attribute whose runlist to search | |
113 | * @vcn: vcn to convert | |
114 | * @write_locked: true if the runlist is locked for writing | |
115 | * | |
116 | * Find the virtual cluster number @vcn in the runlist of the ntfs attribute | |
117 | * described by the ntfs inode @ni and return the corresponding logical cluster | |
118 | * number (lcn). | |
119 | * | |
120 | * If the @vcn is not mapped yet, the attempt is made to map the attribute | |
121 | * extent containing the @vcn and the vcn to lcn conversion is retried. | |
122 | * | |
123 | * If @write_locked is true the caller has locked the runlist for writing and | |
124 | * if false for reading. | |
125 | * | |
126 | * Since lcns must be >= 0, we use negative return codes with special meaning: | |
127 | * | |
128 | * Return code Meaning / Description | |
129 | * ========================================== | |
130 | * LCN_HOLE Hole / not allocated on disk. | |
131 | * LCN_ENOENT There is no such vcn in the runlist, i.e. @vcn is out of bounds. | |
132 | * LCN_ENOMEM Not enough memory to map runlist. | |
133 | * LCN_EIO Critical error (runlist/file is corrupt, i/o error, etc). | |
134 | * | |
135 | * Locking: - The runlist must be locked on entry and is left locked on return. | |
136 | * - If @write_locked is FALSE, i.e. the runlist is locked for reading, | |
137 | * the lock may be dropped inside the function so you cannot rely on | |
138 | * the runlist still being the same when this function returns. | |
139 | */ | |
140 | LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, | |
141 | const BOOL write_locked) | |
142 | { | |
143 | LCN lcn; | |
144 | BOOL is_retry = FALSE; | |
145 | ||
146 | ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.", | |
147 | ni->mft_no, (unsigned long long)vcn, | |
148 | write_locked ? "write" : "read"); | |
149 | BUG_ON(!ni); | |
150 | BUG_ON(!NInoNonResident(ni)); | |
151 | BUG_ON(vcn < 0); | |
152 | retry_remap: | |
153 | /* Convert vcn to lcn. If that fails map the runlist and retry once. */ | |
154 | lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn); | |
155 | if (likely(lcn >= LCN_HOLE)) { | |
156 | ntfs_debug("Done, lcn 0x%llx.", (long long)lcn); | |
157 | return lcn; | |
158 | } | |
159 | if (lcn != LCN_RL_NOT_MAPPED) { | |
160 | if (lcn != LCN_ENOENT) | |
161 | lcn = LCN_EIO; | |
162 | } else if (!is_retry) { | |
163 | int err; | |
164 | ||
165 | if (!write_locked) { | |
166 | up_read(&ni->runlist.lock); | |
167 | down_write(&ni->runlist.lock); | |
168 | if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) != | |
169 | LCN_RL_NOT_MAPPED)) { | |
170 | up_write(&ni->runlist.lock); | |
171 | down_read(&ni->runlist.lock); | |
172 | goto retry_remap; | |
173 | } | |
174 | } | |
175 | err = ntfs_map_runlist_nolock(ni, vcn); | |
176 | if (!write_locked) { | |
177 | up_write(&ni->runlist.lock); | |
178 | down_read(&ni->runlist.lock); | |
179 | } | |
180 | if (likely(!err)) { | |
181 | is_retry = TRUE; | |
182 | goto retry_remap; | |
183 | } | |
184 | if (err == -ENOENT) | |
185 | lcn = LCN_ENOENT; | |
186 | else if (err == -ENOMEM) | |
187 | lcn = LCN_ENOMEM; | |
188 | else | |
189 | lcn = LCN_EIO; | |
190 | } | |
191 | if (lcn != LCN_ENOENT) | |
192 | ntfs_error(ni->vol->sb, "Failed with error code %lli.", | |
193 | (long long)lcn); | |
194 | return lcn; | |
195 | } | |
196 | ||
b6ad6c52 | 197 | /** |
c0c1cc0e | 198 | * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode |
b6ad6c52 AA |
199 | * @ni: ntfs inode describing the runlist to search |
200 | * @vcn: vcn to find | |
201 | * @write_locked: true if the runlist is locked for writing | |
1da177e4 LT |
202 | * |
203 | * Find the virtual cluster number @vcn in the runlist described by the ntfs | |
204 | * inode @ni and return the address of the runlist element containing the @vcn. | |
b6ad6c52 | 205 | * |
c0c1cc0e AA |
206 | * If the @vcn is not mapped yet, the attempt is made to map the attribute |
207 | * extent containing the @vcn and the vcn to lcn conversion is retried. | |
208 | * | |
209 | * If @write_locked is true the caller has locked the runlist for writing and | |
210 | * if false for reading. | |
1da177e4 LT |
211 | * |
212 | * Note you need to distinguish between the lcn of the returned runlist element | |
213 | * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on | |
214 | * read and allocate clusters on write. | |
215 | * | |
216 | * Return the runlist element containing the @vcn on success and | |
217 | * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR() | |
218 | * to decide if the return is success or failure and PTR_ERR() to get to the | |
219 | * error code if IS_ERR() is true. | |
220 | * | |
221 | * The possible error return codes are: | |
222 | * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds. | |
223 | * -ENOMEM - Not enough memory to map runlist. | |
224 | * -EIO - Critical error (runlist/file is corrupt, i/o error, etc). | |
225 | * | |
c0c1cc0e AA |
226 | * Locking: - The runlist must be locked on entry and is left locked on return. |
227 | * - If @write_locked is FALSE, i.e. the runlist is locked for reading, | |
228 | * the lock may be dropped inside the function so you cannot rely on | |
229 | * the runlist still being the same when this function returns. | |
1da177e4 | 230 | */ |
c0c1cc0e | 231 | runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, |
b6ad6c52 | 232 | const BOOL write_locked) |
1da177e4 LT |
233 | { |
234 | runlist_element *rl; | |
235 | int err = 0; | |
236 | BOOL is_retry = FALSE; | |
237 | ||
b6ad6c52 | 238 | ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.", |
1da177e4 | 239 | ni->mft_no, (unsigned long long)vcn, |
b6ad6c52 | 240 | write_locked ? "write" : "read"); |
1da177e4 LT |
241 | BUG_ON(!ni); |
242 | BUG_ON(!NInoNonResident(ni)); | |
243 | BUG_ON(vcn < 0); | |
b6ad6c52 | 244 | retry_remap: |
1da177e4 LT |
245 | rl = ni->runlist.rl; |
246 | if (likely(rl && vcn >= rl[0].vcn)) { | |
247 | while (likely(rl->length)) { | |
b6ad6c52 | 248 | if (unlikely(vcn < rl[1].vcn)) { |
1da177e4 LT |
249 | if (likely(rl->lcn >= LCN_HOLE)) { |
250 | ntfs_debug("Done."); | |
251 | return rl; | |
252 | } | |
253 | break; | |
254 | } | |
255 | rl++; | |
256 | } | |
257 | if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) { | |
258 | if (likely(rl->lcn == LCN_ENOENT)) | |
259 | err = -ENOENT; | |
260 | else | |
261 | err = -EIO; | |
262 | } | |
263 | } | |
1da177e4 LT |
264 | if (!err && !is_retry) { |
265 | /* | |
266 | * The @vcn is in an unmapped region, map the runlist and | |
267 | * retry. | |
268 | */ | |
b6ad6c52 AA |
269 | if (!write_locked) { |
270 | up_read(&ni->runlist.lock); | |
271 | down_write(&ni->runlist.lock); | |
c0c1cc0e AA |
272 | if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) != |
273 | LCN_RL_NOT_MAPPED)) { | |
274 | up_write(&ni->runlist.lock); | |
275 | down_read(&ni->runlist.lock); | |
276 | goto retry_remap; | |
277 | } | |
b6ad6c52 AA |
278 | } |
279 | err = ntfs_map_runlist_nolock(ni, vcn); | |
280 | if (!write_locked) { | |
281 | up_write(&ni->runlist.lock); | |
282 | down_read(&ni->runlist.lock); | |
283 | } | |
1da177e4 LT |
284 | if (likely(!err)) { |
285 | is_retry = TRUE; | |
b6ad6c52 | 286 | goto retry_remap; |
1da177e4 LT |
287 | } |
288 | /* | |
289 | * -EINVAL and -ENOENT coming from a failed mapping attempt are | |
290 | * equivalent to i/o errors for us as they should not happen in | |
291 | * our code paths. | |
292 | */ | |
293 | if (err == -EINVAL || err == -ENOENT) | |
294 | err = -EIO; | |
295 | } else if (!err) | |
296 | err = -EIO; | |
b6ad6c52 AA |
297 | if (err != -ENOENT) |
298 | ntfs_error(ni->vol->sb, "Failed with error code %i.", err); | |
1da177e4 LT |
299 | return ERR_PTR(err); |
300 | } | |
301 | ||
302 | /** | |
303 | * ntfs_attr_find - find (next) attribute in mft record | |
304 | * @type: attribute type to find | |
305 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
306 | * @name_len: attribute name length (only needed if @name present) | |
307 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
308 | * @val: attribute value to find (optional, resident attributes only) | |
309 | * @val_len: attribute value length | |
310 | * @ctx: search context with mft record and attribute to search from | |
311 | * | |
312 | * You should not need to call this function directly. Use ntfs_attr_lookup() | |
313 | * instead. | |
314 | * | |
315 | * ntfs_attr_find() takes a search context @ctx as parameter and searches the | |
316 | * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an | |
317 | * attribute of @type, optionally @name and @val. | |
318 | * | |
319 | * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will | |
320 | * point to the found attribute. | |
321 | * | |
322 | * If the attribute is not found, ntfs_attr_find() returns -ENOENT and | |
323 | * @ctx->attr will point to the attribute before which the attribute being | |
324 | * searched for would need to be inserted if such an action were to be desired. | |
325 | * | |
326 | * On actual error, ntfs_attr_find() returns -EIO. In this case @ctx->attr is | |
327 | * undefined and in particular do not rely on it not changing. | |
328 | * | |
329 | * If @ctx->is_first is TRUE, the search begins with @ctx->attr itself. If it | |
330 | * is FALSE, the search begins after @ctx->attr. | |
331 | * | |
332 | * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and | |
333 | * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record | |
334 | * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at | |
335 | * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case | |
336 | * sensitive. When @name is present, @name_len is the @name length in Unicode | |
337 | * characters. | |
338 | * | |
339 | * If @name is not present (NULL), we assume that the unnamed attribute is | |
340 | * being searched for. | |
341 | * | |
342 | * Finally, the resident attribute value @val is looked for, if present. If | |
343 | * @val is not present (NULL), @val_len is ignored. | |
344 | * | |
345 | * ntfs_attr_find() only searches the specified mft record and it ignores the | |
346 | * presence of an attribute list attribute (unless it is the one being searched | |
347 | * for, obviously). If you need to take attribute lists into consideration, | |
348 | * use ntfs_attr_lookup() instead (see below). This also means that you cannot | |
349 | * use ntfs_attr_find() to search for extent records of non-resident | |
350 | * attributes, as extents with lowest_vcn != 0 are usually described by the | |
351 | * attribute list attribute only. - Note that it is possible that the first | |
352 | * extent is only in the attribute list while the last extent is in the base | |
353 | * mft record, so do not rely on being able to find the first extent in the | |
354 | * base mft record. | |
355 | * | |
356 | * Warning: Never use @val when looking for attribute types which can be | |
357 | * non-resident as this most likely will result in a crash! | |
358 | */ | |
359 | static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, | |
360 | const u32 name_len, const IGNORE_CASE_BOOL ic, | |
361 | const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx) | |
362 | { | |
363 | ATTR_RECORD *a; | |
364 | ntfs_volume *vol = ctx->ntfs_ino->vol; | |
365 | ntfschar *upcase = vol->upcase; | |
366 | u32 upcase_len = vol->upcase_len; | |
367 | ||
368 | /* | |
369 | * Iterate over attributes in mft record starting at @ctx->attr, or the | |
370 | * attribute following that, if @ctx->is_first is TRUE. | |
371 | */ | |
372 | if (ctx->is_first) { | |
373 | a = ctx->attr; | |
374 | ctx->is_first = FALSE; | |
375 | } else | |
376 | a = (ATTR_RECORD*)((u8*)ctx->attr + | |
377 | le32_to_cpu(ctx->attr->length)); | |
378 | for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) { | |
379 | if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec + | |
380 | le32_to_cpu(ctx->mrec->bytes_allocated)) | |
381 | break; | |
382 | ctx->attr = a; | |
383 | if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) || | |
384 | a->type == AT_END)) | |
385 | return -ENOENT; | |
386 | if (unlikely(!a->length)) | |
387 | break; | |
388 | if (a->type != type) | |
389 | continue; | |
390 | /* | |
391 | * If @name is present, compare the two names. If @name is | |
392 | * missing, assume we want an unnamed attribute. | |
393 | */ | |
394 | if (!name) { | |
395 | /* The search failed if the found attribute is named. */ | |
396 | if (a->name_length) | |
397 | return -ENOENT; | |
398 | } else if (!ntfs_are_names_equal(name, name_len, | |
399 | (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)), | |
400 | a->name_length, ic, upcase, upcase_len)) { | |
401 | register int rc; | |
402 | ||
403 | rc = ntfs_collate_names(name, name_len, | |
404 | (ntfschar*)((u8*)a + | |
405 | le16_to_cpu(a->name_offset)), | |
406 | a->name_length, 1, IGNORE_CASE, | |
407 | upcase, upcase_len); | |
408 | /* | |
409 | * If @name collates before a->name, there is no | |
410 | * matching attribute. | |
411 | */ | |
412 | if (rc == -1) | |
413 | return -ENOENT; | |
414 | /* If the strings are not equal, continue search. */ | |
415 | if (rc) | |
416 | continue; | |
417 | rc = ntfs_collate_names(name, name_len, | |
418 | (ntfschar*)((u8*)a + | |
419 | le16_to_cpu(a->name_offset)), | |
420 | a->name_length, 1, CASE_SENSITIVE, | |
421 | upcase, upcase_len); | |
422 | if (rc == -1) | |
423 | return -ENOENT; | |
424 | if (rc) | |
425 | continue; | |
426 | } | |
427 | /* | |
428 | * The names match or @name not present and attribute is | |
429 | * unnamed. If no @val specified, we have found the attribute | |
430 | * and are done. | |
431 | */ | |
432 | if (!val) | |
433 | return 0; | |
434 | /* @val is present; compare values. */ | |
435 | else { | |
436 | register int rc; | |
437 | ||
438 | rc = memcmp(val, (u8*)a + le16_to_cpu( | |
439 | a->data.resident.value_offset), | |
440 | min_t(u32, val_len, le32_to_cpu( | |
441 | a->data.resident.value_length))); | |
442 | /* | |
443 | * If @val collates before the current attribute's | |
444 | * value, there is no matching attribute. | |
445 | */ | |
446 | if (!rc) { | |
447 | register u32 avl; | |
448 | ||
449 | avl = le32_to_cpu( | |
450 | a->data.resident.value_length); | |
451 | if (val_len == avl) | |
452 | return 0; | |
453 | if (val_len < avl) | |
454 | return -ENOENT; | |
455 | } else if (rc < 0) | |
456 | return -ENOENT; | |
457 | } | |
458 | } | |
459 | ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk."); | |
460 | NVolSetErrors(vol); | |
461 | return -EIO; | |
462 | } | |
463 | ||
464 | /** | |
465 | * load_attribute_list - load an attribute list into memory | |
466 | * @vol: ntfs volume from which to read | |
467 | * @runlist: runlist of the attribute list | |
468 | * @al_start: destination buffer | |
469 | * @size: size of the destination buffer in bytes | |
470 | * @initialized_size: initialized size of the attribute list | |
471 | * | |
472 | * Walk the runlist @runlist and load all clusters from it copying them into | |
473 | * the linear buffer @al. The maximum number of bytes copied to @al is @size | |
474 | * bytes. Note, @size does not need to be a multiple of the cluster size. If | |
475 | * @initialized_size is less than @size, the region in @al between | |
476 | * @initialized_size and @size will be zeroed and not read from disk. | |
477 | * | |
478 | * Return 0 on success or -errno on error. | |
479 | */ | |
480 | int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start, | |
481 | const s64 size, const s64 initialized_size) | |
482 | { | |
483 | LCN lcn; | |
484 | u8 *al = al_start; | |
485 | u8 *al_end = al + initialized_size; | |
486 | runlist_element *rl; | |
487 | struct buffer_head *bh; | |
488 | struct super_block *sb; | |
489 | unsigned long block_size; | |
490 | unsigned long block, max_block; | |
491 | int err = 0; | |
492 | unsigned char block_size_bits; | |
493 | ||
494 | ntfs_debug("Entering."); | |
495 | if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 || | |
496 | initialized_size > size) | |
497 | return -EINVAL; | |
498 | if (!initialized_size) { | |
499 | memset(al, 0, size); | |
500 | return 0; | |
501 | } | |
502 | sb = vol->sb; | |
503 | block_size = sb->s_blocksize; | |
504 | block_size_bits = sb->s_blocksize_bits; | |
505 | down_read(&runlist->lock); | |
506 | rl = runlist->rl; | |
507 | /* Read all clusters specified by the runlist one run at a time. */ | |
508 | while (rl->length) { | |
509 | lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn); | |
510 | ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.", | |
511 | (unsigned long long)rl->vcn, | |
512 | (unsigned long long)lcn); | |
513 | /* The attribute list cannot be sparse. */ | |
514 | if (lcn < 0) { | |
515 | ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed. Cannot " | |
516 | "read attribute list."); | |
517 | goto err_out; | |
518 | } | |
519 | block = lcn << vol->cluster_size_bits >> block_size_bits; | |
520 | /* Read the run from device in chunks of block_size bytes. */ | |
521 | max_block = block + (rl->length << vol->cluster_size_bits >> | |
522 | block_size_bits); | |
523 | ntfs_debug("max_block = 0x%lx.", max_block); | |
524 | do { | |
525 | ntfs_debug("Reading block = 0x%lx.", block); | |
526 | bh = sb_bread(sb, block); | |
527 | if (!bh) { | |
528 | ntfs_error(sb, "sb_bread() failed. Cannot " | |
529 | "read attribute list."); | |
530 | goto err_out; | |
531 | } | |
532 | if (al + block_size >= al_end) | |
533 | goto do_final; | |
534 | memcpy(al, bh->b_data, block_size); | |
535 | brelse(bh); | |
536 | al += block_size; | |
537 | } while (++block < max_block); | |
538 | rl++; | |
539 | } | |
540 | if (initialized_size < size) { | |
541 | initialize: | |
542 | memset(al_start + initialized_size, 0, size - initialized_size); | |
543 | } | |
544 | done: | |
545 | up_read(&runlist->lock); | |
546 | return err; | |
547 | do_final: | |
548 | if (al < al_end) { | |
549 | /* | |
550 | * Partial block. | |
551 | * | |
552 | * Note: The attribute list can be smaller than its allocation | |
553 | * by multiple clusters. This has been encountered by at least | |
554 | * two people running Windows XP, thus we cannot do any | |
555 | * truncation sanity checking here. (AIA) | |
556 | */ | |
557 | memcpy(al, bh->b_data, al_end - al); | |
558 | brelse(bh); | |
559 | if (initialized_size < size) | |
560 | goto initialize; | |
561 | goto done; | |
562 | } | |
563 | brelse(bh); | |
564 | /* Real overflow! */ | |
565 | ntfs_error(sb, "Attribute list buffer overflow. Read attribute list " | |
566 | "is truncated."); | |
567 | err_out: | |
568 | err = -EIO; | |
569 | goto done; | |
570 | } | |
571 | ||
572 | /** | |
573 | * ntfs_external_attr_find - find an attribute in the attribute list of an inode | |
574 | * @type: attribute type to find | |
575 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
576 | * @name_len: attribute name length (only needed if @name present) | |
577 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
578 | * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only) | |
579 | * @val: attribute value to find (optional, resident attributes only) | |
580 | * @val_len: attribute value length | |
581 | * @ctx: search context with mft record and attribute to search from | |
582 | * | |
583 | * You should not need to call this function directly. Use ntfs_attr_lookup() | |
584 | * instead. | |
585 | * | |
586 | * Find an attribute by searching the attribute list for the corresponding | |
587 | * attribute list entry. Having found the entry, map the mft record if the | |
588 | * attribute is in a different mft record/inode, ntfs_attr_find() the attribute | |
589 | * in there and return it. | |
590 | * | |
591 | * On first search @ctx->ntfs_ino must be the base mft record and @ctx must | |
592 | * have been obtained from a call to ntfs_attr_get_search_ctx(). On subsequent | |
593 | * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is | |
594 | * then the base inode). | |
595 | * | |
596 | * After finishing with the attribute/mft record you need to call | |
597 | * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any | |
598 | * mapped inodes, etc). | |
599 | * | |
600 | * If the attribute is found, ntfs_external_attr_find() returns 0 and | |
601 | * @ctx->attr will point to the found attribute. @ctx->mrec will point to the | |
602 | * mft record in which @ctx->attr is located and @ctx->al_entry will point to | |
603 | * the attribute list entry for the attribute. | |
604 | * | |
605 | * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and | |
606 | * @ctx->attr will point to the attribute in the base mft record before which | |
607 | * the attribute being searched for would need to be inserted if such an action | |
608 | * were to be desired. @ctx->mrec will point to the mft record in which | |
609 | * @ctx->attr is located and @ctx->al_entry will point to the attribute list | |
610 | * entry of the attribute before which the attribute being searched for would | |
611 | * need to be inserted if such an action were to be desired. | |
612 | * | |
613 | * Thus to insert the not found attribute, one wants to add the attribute to | |
614 | * @ctx->mrec (the base mft record) and if there is not enough space, the | |
615 | * attribute should be placed in a newly allocated extent mft record. The | |
616 | * attribute list entry for the inserted attribute should be inserted in the | |
617 | * attribute list attribute at @ctx->al_entry. | |
618 | * | |
619 | * On actual error, ntfs_external_attr_find() returns -EIO. In this case | |
620 | * @ctx->attr is undefined and in particular do not rely on it not changing. | |
621 | */ | |
622 | static int ntfs_external_attr_find(const ATTR_TYPE type, | |
623 | const ntfschar *name, const u32 name_len, | |
624 | const IGNORE_CASE_BOOL ic, const VCN lowest_vcn, | |
625 | const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx) | |
626 | { | |
627 | ntfs_inode *base_ni, *ni; | |
628 | ntfs_volume *vol; | |
629 | ATTR_LIST_ENTRY *al_entry, *next_al_entry; | |
630 | u8 *al_start, *al_end; | |
631 | ATTR_RECORD *a; | |
632 | ntfschar *al_name; | |
633 | u32 al_name_len; | |
634 | int err = 0; | |
635 | static const char *es = " Unmount and run chkdsk."; | |
636 | ||
637 | ni = ctx->ntfs_ino; | |
638 | base_ni = ctx->base_ntfs_ino; | |
639 | ntfs_debug("Entering for inode 0x%lx, type 0x%x.", ni->mft_no, type); | |
640 | if (!base_ni) { | |
641 | /* First call happens with the base mft record. */ | |
642 | base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino; | |
643 | ctx->base_mrec = ctx->mrec; | |
644 | } | |
645 | if (ni == base_ni) | |
646 | ctx->base_attr = ctx->attr; | |
647 | if (type == AT_END) | |
648 | goto not_found; | |
649 | vol = base_ni->vol; | |
650 | al_start = base_ni->attr_list; | |
651 | al_end = al_start + base_ni->attr_list_size; | |
652 | if (!ctx->al_entry) | |
653 | ctx->al_entry = (ATTR_LIST_ENTRY*)al_start; | |
654 | /* | |
655 | * Iterate over entries in attribute list starting at @ctx->al_entry, | |
656 | * or the entry following that, if @ctx->is_first is TRUE. | |
657 | */ | |
658 | if (ctx->is_first) { | |
659 | al_entry = ctx->al_entry; | |
660 | ctx->is_first = FALSE; | |
661 | } else | |
662 | al_entry = (ATTR_LIST_ENTRY*)((u8*)ctx->al_entry + | |
663 | le16_to_cpu(ctx->al_entry->length)); | |
664 | for (;; al_entry = next_al_entry) { | |
665 | /* Out of bounds check. */ | |
666 | if ((u8*)al_entry < base_ni->attr_list || | |
667 | (u8*)al_entry > al_end) | |
668 | break; /* Inode is corrupt. */ | |
669 | ctx->al_entry = al_entry; | |
670 | /* Catch the end of the attribute list. */ | |
671 | if ((u8*)al_entry == al_end) | |
672 | goto not_found; | |
673 | if (!al_entry->length) | |
674 | break; | |
675 | if ((u8*)al_entry + 6 > al_end || (u8*)al_entry + | |
676 | le16_to_cpu(al_entry->length) > al_end) | |
677 | break; | |
678 | next_al_entry = (ATTR_LIST_ENTRY*)((u8*)al_entry + | |
679 | le16_to_cpu(al_entry->length)); | |
680 | if (le32_to_cpu(al_entry->type) > le32_to_cpu(type)) | |
681 | goto not_found; | |
682 | if (type != al_entry->type) | |
683 | continue; | |
684 | /* | |
685 | * If @name is present, compare the two names. If @name is | |
686 | * missing, assume we want an unnamed attribute. | |
687 | */ | |
688 | al_name_len = al_entry->name_length; | |
689 | al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset); | |
690 | if (!name) { | |
691 | if (al_name_len) | |
692 | goto not_found; | |
693 | } else if (!ntfs_are_names_equal(al_name, al_name_len, name, | |
694 | name_len, ic, vol->upcase, vol->upcase_len)) { | |
695 | register int rc; | |
696 | ||
697 | rc = ntfs_collate_names(name, name_len, al_name, | |
698 | al_name_len, 1, IGNORE_CASE, | |
699 | vol->upcase, vol->upcase_len); | |
700 | /* | |
701 | * If @name collates before al_name, there is no | |
702 | * matching attribute. | |
703 | */ | |
704 | if (rc == -1) | |
705 | goto not_found; | |
706 | /* If the strings are not equal, continue search. */ | |
707 | if (rc) | |
708 | continue; | |
709 | /* | |
710 | * FIXME: Reverse engineering showed 0, IGNORE_CASE but | |
711 | * that is inconsistent with ntfs_attr_find(). The | |
712 | * subsequent rc checks were also different. Perhaps I | |
713 | * made a mistake in one of the two. Need to recheck | |
714 | * which is correct or at least see what is going on... | |
715 | * (AIA) | |
716 | */ | |
717 | rc = ntfs_collate_names(name, name_len, al_name, | |
718 | al_name_len, 1, CASE_SENSITIVE, | |
719 | vol->upcase, vol->upcase_len); | |
720 | if (rc == -1) | |
721 | goto not_found; | |
722 | if (rc) | |
723 | continue; | |
724 | } | |
725 | /* | |
726 | * The names match or @name not present and attribute is | |
727 | * unnamed. Now check @lowest_vcn. Continue search if the | |
728 | * next attribute list entry still fits @lowest_vcn. Otherwise | |
729 | * we have reached the right one or the search has failed. | |
730 | */ | |
731 | if (lowest_vcn && (u8*)next_al_entry >= al_start && | |
732 | (u8*)next_al_entry + 6 < al_end && | |
733 | (u8*)next_al_entry + le16_to_cpu( | |
734 | next_al_entry->length) <= al_end && | |
735 | sle64_to_cpu(next_al_entry->lowest_vcn) <= | |
736 | lowest_vcn && | |
737 | next_al_entry->type == al_entry->type && | |
738 | next_al_entry->name_length == al_name_len && | |
739 | ntfs_are_names_equal((ntfschar*)((u8*) | |
740 | next_al_entry + | |
741 | next_al_entry->name_offset), | |
742 | next_al_entry->name_length, | |
743 | al_name, al_name_len, CASE_SENSITIVE, | |
744 | vol->upcase, vol->upcase_len)) | |
745 | continue; | |
746 | if (MREF_LE(al_entry->mft_reference) == ni->mft_no) { | |
747 | if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) { | |
748 | ntfs_error(vol->sb, "Found stale mft " | |
749 | "reference in attribute list " | |
750 | "of base inode 0x%lx.%s", | |
751 | base_ni->mft_no, es); | |
752 | err = -EIO; | |
753 | break; | |
754 | } | |
755 | } else { /* Mft references do not match. */ | |
756 | /* If there is a mapped record unmap it first. */ | |
757 | if (ni != base_ni) | |
758 | unmap_extent_mft_record(ni); | |
759 | /* Do we want the base record back? */ | |
760 | if (MREF_LE(al_entry->mft_reference) == | |
761 | base_ni->mft_no) { | |
762 | ni = ctx->ntfs_ino = base_ni; | |
763 | ctx->mrec = ctx->base_mrec; | |
764 | } else { | |
765 | /* We want an extent record. */ | |
766 | ctx->mrec = map_extent_mft_record(base_ni, | |
767 | le64_to_cpu( | |
768 | al_entry->mft_reference), &ni); | |
769 | if (IS_ERR(ctx->mrec)) { | |
770 | ntfs_error(vol->sb, "Failed to map " | |
771 | "extent mft record " | |
772 | "0x%lx of base inode " | |
773 | "0x%lx.%s", | |
774 | MREF_LE(al_entry-> | |
775 | mft_reference), | |
776 | base_ni->mft_no, es); | |
777 | err = PTR_ERR(ctx->mrec); | |
778 | if (err == -ENOENT) | |
779 | err = -EIO; | |
780 | /* Cause @ctx to be sanitized below. */ | |
781 | ni = NULL; | |
782 | break; | |
783 | } | |
784 | ctx->ntfs_ino = ni; | |
785 | } | |
786 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
787 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
788 | } | |
789 | /* | |
790 | * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the | |
791 | * mft record containing the attribute represented by the | |
792 | * current al_entry. | |
793 | */ | |
794 | /* | |
795 | * We could call into ntfs_attr_find() to find the right | |
796 | * attribute in this mft record but this would be less | |
797 | * efficient and not quite accurate as ntfs_attr_find() ignores | |
798 | * the attribute instance numbers for example which become | |
799 | * important when one plays with attribute lists. Also, | |
800 | * because a proper match has been found in the attribute list | |
801 | * entry above, the comparison can now be optimized. So it is | |
802 | * worth re-implementing a simplified ntfs_attr_find() here. | |
803 | */ | |
804 | a = ctx->attr; | |
805 | /* | |
806 | * Use a manual loop so we can still use break and continue | |
807 | * with the same meanings as above. | |
808 | */ | |
809 | do_next_attr_loop: | |
810 | if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec + | |
811 | le32_to_cpu(ctx->mrec->bytes_allocated)) | |
812 | break; | |
813 | if (a->type == AT_END) | |
814 | continue; | |
815 | if (!a->length) | |
816 | break; | |
817 | if (al_entry->instance != a->instance) | |
818 | goto do_next_attr; | |
819 | /* | |
820 | * If the type and/or the name are mismatched between the | |
821 | * attribute list entry and the attribute record, there is | |
822 | * corruption so we break and return error EIO. | |
823 | */ | |
824 | if (al_entry->type != a->type) | |
825 | break; | |
826 | if (!ntfs_are_names_equal((ntfschar*)((u8*)a + | |
827 | le16_to_cpu(a->name_offset)), a->name_length, | |
828 | al_name, al_name_len, CASE_SENSITIVE, | |
829 | vol->upcase, vol->upcase_len)) | |
830 | break; | |
831 | ctx->attr = a; | |
832 | /* | |
833 | * If no @val specified or @val specified and it matches, we | |
834 | * have found it! | |
835 | */ | |
836 | if (!val || (!a->non_resident && le32_to_cpu( | |
837 | a->data.resident.value_length) == val_len && | |
838 | !memcmp((u8*)a + | |
839 | le16_to_cpu(a->data.resident.value_offset), | |
840 | val, val_len))) { | |
841 | ntfs_debug("Done, found."); | |
842 | return 0; | |
843 | } | |
844 | do_next_attr: | |
845 | /* Proceed to the next attribute in the current mft record. */ | |
846 | a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length)); | |
847 | goto do_next_attr_loop; | |
848 | } | |
849 | if (!err) { | |
850 | ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt " | |
851 | "attribute list attribute.%s", base_ni->mft_no, | |
852 | es); | |
853 | err = -EIO; | |
854 | } | |
855 | if (ni != base_ni) { | |
856 | if (ni) | |
857 | unmap_extent_mft_record(ni); | |
858 | ctx->ntfs_ino = base_ni; | |
859 | ctx->mrec = ctx->base_mrec; | |
860 | ctx->attr = ctx->base_attr; | |
861 | } | |
862 | if (err != -ENOMEM) | |
863 | NVolSetErrors(vol); | |
864 | return err; | |
865 | not_found: | |
866 | /* | |
867 | * If we were looking for AT_END, we reset the search context @ctx and | |
868 | * use ntfs_attr_find() to seek to the end of the base mft record. | |
869 | */ | |
870 | if (type == AT_END) { | |
871 | ntfs_attr_reinit_search_ctx(ctx); | |
872 | return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len, | |
873 | ctx); | |
874 | } | |
875 | /* | |
876 | * The attribute was not found. Before we return, we want to ensure | |
877 | * @ctx->mrec and @ctx->attr indicate the position at which the | |
878 | * attribute should be inserted in the base mft record. Since we also | |
879 | * want to preserve @ctx->al_entry we cannot reinitialize the search | |
880 | * context using ntfs_attr_reinit_search_ctx() as this would set | |
881 | * @ctx->al_entry to NULL. Thus we do the necessary bits manually (see | |
882 | * ntfs_attr_init_search_ctx() below). Note, we _only_ preserve | |
883 | * @ctx->al_entry as the remaining fields (base_*) are identical to | |
884 | * their non base_ counterparts and we cannot set @ctx->base_attr | |
885 | * correctly yet as we do not know what @ctx->attr will be set to by | |
886 | * the call to ntfs_attr_find() below. | |
887 | */ | |
888 | if (ni != base_ni) | |
889 | unmap_extent_mft_record(ni); | |
890 | ctx->mrec = ctx->base_mrec; | |
891 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
892 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
893 | ctx->is_first = TRUE; | |
894 | ctx->ntfs_ino = base_ni; | |
895 | ctx->base_ntfs_ino = NULL; | |
896 | ctx->base_mrec = NULL; | |
897 | ctx->base_attr = NULL; | |
898 | /* | |
899 | * In case there are multiple matches in the base mft record, need to | |
900 | * keep enumerating until we get an attribute not found response (or | |
901 | * another error), otherwise we would keep returning the same attribute | |
902 | * over and over again and all programs using us for enumeration would | |
903 | * lock up in a tight loop. | |
904 | */ | |
905 | do { | |
906 | err = ntfs_attr_find(type, name, name_len, ic, val, val_len, | |
907 | ctx); | |
908 | } while (!err); | |
909 | ntfs_debug("Done, not found."); | |
910 | return err; | |
911 | } | |
912 | ||
913 | /** | |
914 | * ntfs_attr_lookup - find an attribute in an ntfs inode | |
915 | * @type: attribute type to find | |
916 | * @name: attribute name to find (optional, i.e. NULL means don't care) | |
917 | * @name_len: attribute name length (only needed if @name present) | |
918 | * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present) | |
919 | * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only) | |
920 | * @val: attribute value to find (optional, resident attributes only) | |
921 | * @val_len: attribute value length | |
922 | * @ctx: search context with mft record and attribute to search from | |
923 | * | |
924 | * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must | |
925 | * be the base mft record and @ctx must have been obtained from a call to | |
926 | * ntfs_attr_get_search_ctx(). | |
927 | * | |
928 | * This function transparently handles attribute lists and @ctx is used to | |
929 | * continue searches where they were left off at. | |
930 | * | |
931 | * After finishing with the attribute/mft record you need to call | |
932 | * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any | |
933 | * mapped inodes, etc). | |
934 | * | |
935 | * Return 0 if the search was successful and -errno if not. | |
936 | * | |
937 | * When 0, @ctx->attr is the found attribute and it is in mft record | |
938 | * @ctx->mrec. If an attribute list attribute is present, @ctx->al_entry is | |
939 | * the attribute list entry of the found attribute. | |
940 | * | |
941 | * When -ENOENT, @ctx->attr is the attribute which collates just after the | |
942 | * attribute being searched for, i.e. if one wants to add the attribute to the | |
943 | * mft record this is the correct place to insert it into. If an attribute | |
944 | * list attribute is present, @ctx->al_entry is the attribute list entry which | |
945 | * collates just after the attribute list entry of the attribute being searched | |
946 | * for, i.e. if one wants to add the attribute to the mft record this is the | |
947 | * correct place to insert its attribute list entry into. | |
948 | * | |
949 | * When -errno != -ENOENT, an error occured during the lookup. @ctx->attr is | |
950 | * then undefined and in particular you should not rely on it not changing. | |
951 | */ | |
952 | int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name, | |
953 | const u32 name_len, const IGNORE_CASE_BOOL ic, | |
954 | const VCN lowest_vcn, const u8 *val, const u32 val_len, | |
955 | ntfs_attr_search_ctx *ctx) | |
956 | { | |
957 | ntfs_inode *base_ni; | |
958 | ||
959 | ntfs_debug("Entering."); | |
960 | if (ctx->base_ntfs_ino) | |
961 | base_ni = ctx->base_ntfs_ino; | |
962 | else | |
963 | base_ni = ctx->ntfs_ino; | |
964 | /* Sanity check, just for debugging really. */ | |
965 | BUG_ON(!base_ni); | |
966 | if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST) | |
967 | return ntfs_attr_find(type, name, name_len, ic, val, val_len, | |
968 | ctx); | |
969 | return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn, | |
970 | val, val_len, ctx); | |
971 | } | |
972 | ||
973 | /** | |
974 | * ntfs_attr_init_search_ctx - initialize an attribute search context | |
975 | * @ctx: attribute search context to initialize | |
976 | * @ni: ntfs inode with which to initialize the search context | |
977 | * @mrec: mft record with which to initialize the search context | |
978 | * | |
979 | * Initialize the attribute search context @ctx with @ni and @mrec. | |
980 | */ | |
981 | static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx, | |
982 | ntfs_inode *ni, MFT_RECORD *mrec) | |
983 | { | |
984 | ctx->mrec = mrec; | |
985 | /* Sanity checks are performed elsewhere. */ | |
986 | ctx->attr = (ATTR_RECORD*)((u8*)mrec + le16_to_cpu(mrec->attrs_offset)); | |
987 | ctx->is_first = TRUE; | |
988 | ctx->ntfs_ino = ni; | |
989 | ctx->al_entry = NULL; | |
990 | ctx->base_ntfs_ino = NULL; | |
991 | ctx->base_mrec = NULL; | |
992 | ctx->base_attr = NULL; | |
993 | } | |
994 | ||
995 | /** | |
996 | * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context | |
997 | * @ctx: attribute search context to reinitialize | |
998 | * | |
999 | * Reinitialize the attribute search context @ctx, unmapping an associated | |
1000 | * extent mft record if present, and initialize the search context again. | |
1001 | * | |
1002 | * This is used when a search for a new attribute is being started to reset | |
1003 | * the search context to the beginning. | |
1004 | */ | |
1005 | void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx) | |
1006 | { | |
1007 | if (likely(!ctx->base_ntfs_ino)) { | |
1008 | /* No attribute list. */ | |
1009 | ctx->is_first = TRUE; | |
1010 | /* Sanity checks are performed elsewhere. */ | |
1011 | ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec + | |
1012 | le16_to_cpu(ctx->mrec->attrs_offset)); | |
1013 | /* | |
1014 | * This needs resetting due to ntfs_external_attr_find() which | |
1015 | * can leave it set despite having zeroed ctx->base_ntfs_ino. | |
1016 | */ | |
1017 | ctx->al_entry = NULL; | |
1018 | return; | |
1019 | } /* Attribute list. */ | |
1020 | if (ctx->ntfs_ino != ctx->base_ntfs_ino) | |
1021 | unmap_extent_mft_record(ctx->ntfs_ino); | |
1022 | ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec); | |
1023 | return; | |
1024 | } | |
1025 | ||
1026 | /** | |
1027 | * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context | |
1028 | * @ni: ntfs inode with which to initialize the search context | |
1029 | * @mrec: mft record with which to initialize the search context | |
1030 | * | |
1031 | * Allocate a new attribute search context, initialize it with @ni and @mrec, | |
1032 | * and return it. Return NULL if allocation failed. | |
1033 | */ | |
1034 | ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec) | |
1035 | { | |
1036 | ntfs_attr_search_ctx *ctx; | |
1037 | ||
1038 | ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, SLAB_NOFS); | |
1039 | if (ctx) | |
1040 | ntfs_attr_init_search_ctx(ctx, ni, mrec); | |
1041 | return ctx; | |
1042 | } | |
1043 | ||
1044 | /** | |
1045 | * ntfs_attr_put_search_ctx - release an attribute search context | |
1046 | * @ctx: attribute search context to free | |
1047 | * | |
1048 | * Release the attribute search context @ctx, unmapping an associated extent | |
1049 | * mft record if present. | |
1050 | */ | |
1051 | void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx) | |
1052 | { | |
1053 | if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino) | |
1054 | unmap_extent_mft_record(ctx->ntfs_ino); | |
1055 | kmem_cache_free(ntfs_attr_ctx_cache, ctx); | |
1056 | return; | |
1057 | } | |
1058 | ||
1059 | /** | |
1060 | * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file | |
1061 | * @vol: ntfs volume to which the attribute belongs | |
1062 | * @type: attribute type which to find | |
1063 | * | |
1064 | * Search for the attribute definition record corresponding to the attribute | |
1065 | * @type in the $AttrDef system file. | |
1066 | * | |
1067 | * Return the attribute type definition record if found and NULL if not found. | |
1068 | */ | |
1069 | static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol, | |
1070 | const ATTR_TYPE type) | |
1071 | { | |
1072 | ATTR_DEF *ad; | |
1073 | ||
1074 | BUG_ON(!vol->attrdef); | |
1075 | BUG_ON(!type); | |
1076 | for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef < | |
1077 | vol->attrdef_size && ad->type; ++ad) { | |
1078 | /* We have not found it yet, carry on searching. */ | |
1079 | if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type))) | |
1080 | continue; | |
1081 | /* We found the attribute; return it. */ | |
1082 | if (likely(ad->type == type)) | |
1083 | return ad; | |
1084 | /* We have gone too far already. No point in continuing. */ | |
1085 | break; | |
1086 | } | |
1087 | /* Attribute not found. */ | |
1088 | ntfs_debug("Attribute type 0x%x not found in $AttrDef.", | |
1089 | le32_to_cpu(type)); | |
1090 | return NULL; | |
1091 | } | |
1092 | ||
1093 | /** | |
1094 | * ntfs_attr_size_bounds_check - check a size of an attribute type for validity | |
1095 | * @vol: ntfs volume to which the attribute belongs | |
1096 | * @type: attribute type which to check | |
1097 | * @size: size which to check | |
1098 | * | |
1099 | * Check whether the @size in bytes is valid for an attribute of @type on the | |
1100 | * ntfs volume @vol. This information is obtained from $AttrDef system file. | |
1101 | * | |
1102 | * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not | |
1103 | * listed in $AttrDef. | |
1104 | */ | |
1105 | int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type, | |
1106 | const s64 size) | |
1107 | { | |
1108 | ATTR_DEF *ad; | |
1109 | ||
1110 | BUG_ON(size < 0); | |
1111 | /* | |
1112 | * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not | |
1113 | * listed in $AttrDef. | |
1114 | */ | |
1115 | if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024)) | |
1116 | return -ERANGE; | |
1117 | /* Get the $AttrDef entry for the attribute @type. */ | |
1118 | ad = ntfs_attr_find_in_attrdef(vol, type); | |
1119 | if (unlikely(!ad)) | |
1120 | return -ENOENT; | |
1121 | /* Do the bounds check. */ | |
1122 | if (((sle64_to_cpu(ad->min_size) > 0) && | |
1123 | size < sle64_to_cpu(ad->min_size)) || | |
1124 | ((sle64_to_cpu(ad->max_size) > 0) && size > | |
1125 | sle64_to_cpu(ad->max_size))) | |
1126 | return -ERANGE; | |
1127 | return 0; | |
1128 | } | |
1129 | ||
1130 | /** | |
1131 | * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident | |
1132 | * @vol: ntfs volume to which the attribute belongs | |
1133 | * @type: attribute type which to check | |
1134 | * | |
1135 | * Check whether the attribute of @type on the ntfs volume @vol is allowed to | |
1136 | * be non-resident. This information is obtained from $AttrDef system file. | |
1137 | * | |
1138 | * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, or | |
1139 | * -ENOENT if the attribute is not listed in $AttrDef. | |
1140 | */ | |
1141 | int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type) | |
1142 | { | |
1143 | ATTR_DEF *ad; | |
1144 | ||
1145 | /* | |
7e693073 AA |
1146 | * $DATA and $EA are always allowed to be non-resident even if $AttrDef |
1147 | * does not specify this in the flags of the $DATA attribute definition | |
1148 | * record. | |
1da177e4 | 1149 | */ |
7e693073 | 1150 | if (type == AT_DATA || type == AT_EA) |
1da177e4 LT |
1151 | return 0; |
1152 | /* Find the attribute definition record in $AttrDef. */ | |
1153 | ad = ntfs_attr_find_in_attrdef(vol, type); | |
1154 | if (unlikely(!ad)) | |
1155 | return -ENOENT; | |
1156 | /* Check the flags and return the result. */ | |
1157 | if (ad->flags & CAN_BE_NON_RESIDENT) | |
1158 | return 0; | |
1159 | return -EPERM; | |
1160 | } | |
1161 | ||
1162 | /** | |
1163 | * ntfs_attr_can_be_resident - check if an attribute can be resident | |
1164 | * @vol: ntfs volume to which the attribute belongs | |
1165 | * @type: attribute type which to check | |
1166 | * | |
1167 | * Check whether the attribute of @type on the ntfs volume @vol is allowed to | |
1168 | * be resident. This information is derived from our ntfs knowledge and may | |
1169 | * not be completely accurate, especially when user defined attributes are | |
1170 | * present. Basically we allow everything to be resident except for index | |
1171 | * allocation and $EA attributes. | |
1172 | * | |
1173 | * Return 0 if the attribute is allowed to be non-resident and -EPERM if not. | |
1174 | * | |
1175 | * Warning: In the system file $MFT the attribute $Bitmap must be non-resident | |
1176 | * otherwise windows will not boot (blue screen of death)! We cannot | |
1177 | * check for this here as we do not know which inode's $Bitmap is | |
1178 | * being asked about so the caller needs to special case this. | |
1179 | */ | |
1180 | int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type) | |
1181 | { | |
1182 | if (type != AT_INDEX_ALLOCATION && type != AT_EA) | |
1183 | return 0; | |
1184 | return -EPERM; | |
1185 | } | |
1186 | ||
1187 | /** | |
1188 | * ntfs_attr_record_resize - resize an attribute record | |
1189 | * @m: mft record containing attribute record | |
1190 | * @a: attribute record to resize | |
1191 | * @new_size: new size in bytes to which to resize the attribute record @a | |
1192 | * | |
1193 | * Resize the attribute record @a, i.e. the resident part of the attribute, in | |
1194 | * the mft record @m to @new_size bytes. | |
1195 | * | |
1196 | * Return 0 on success and -errno on error. The following error codes are | |
1197 | * defined: | |
1198 | * -ENOSPC - Not enough space in the mft record @m to perform the resize. | |
1199 | * | |
1200 | * Note: On error, no modifications have been performed whatsoever. | |
1201 | * | |
1202 | * Warning: If you make a record smaller without having copied all the data you | |
1203 | * are interested in the data may be overwritten. | |
1204 | */ | |
1205 | int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size) | |
1206 | { | |
1207 | ntfs_debug("Entering for new_size %u.", new_size); | |
1208 | /* Align to 8 bytes if it is not already done. */ | |
1209 | if (new_size & 7) | |
1210 | new_size = (new_size + 7) & ~7; | |
1211 | /* If the actual attribute length has changed, move things around. */ | |
1212 | if (new_size != le32_to_cpu(a->length)) { | |
1213 | u32 new_muse = le32_to_cpu(m->bytes_in_use) - | |
1214 | le32_to_cpu(a->length) + new_size; | |
1215 | /* Not enough space in this mft record. */ | |
1216 | if (new_muse > le32_to_cpu(m->bytes_allocated)) | |
1217 | return -ENOSPC; | |
1218 | /* Move attributes following @a to their new location. */ | |
1219 | memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length), | |
1220 | le32_to_cpu(m->bytes_in_use) - ((u8*)a - | |
1221 | (u8*)m) - le32_to_cpu(a->length)); | |
1222 | /* Adjust @m to reflect the change in used space. */ | |
1223 | m->bytes_in_use = cpu_to_le32(new_muse); | |
1224 | /* Adjust @a to reflect the new size. */ | |
1225 | if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length)) | |
1226 | a->length = cpu_to_le32(new_size); | |
1227 | } | |
1228 | return 0; | |
1229 | } | |
1230 | ||
2bfb4fff AA |
1231 | /** |
1232 | * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute | |
1233 | * @ni: ntfs inode describing the attribute to convert | |
1234 | * | |
1235 | * Convert the resident ntfs attribute described by the ntfs inode @ni to a | |
1236 | * non-resident one. | |
1237 | * | |
1238 | * Return 0 on success and -errno on error. The following error return codes | |
1239 | * are defined: | |
1240 | * -EPERM - The attribute is not allowed to be non-resident. | |
1241 | * -ENOMEM - Not enough memory. | |
1242 | * -ENOSPC - Not enough disk space. | |
1243 | * -EINVAL - Attribute not defined on the volume. | |
1244 | * -EIO - I/o error or other error. | |
1245 | * | |
1246 | * NOTE to self: No changes in the attribute list are required to move from | |
1247 | * a resident to a non-resident attribute. | |
1248 | * | |
1249 | * Locking: - The caller must hold i_sem on the inode. | |
1250 | */ | |
1251 | int ntfs_attr_make_non_resident(ntfs_inode *ni) | |
1252 | { | |
1253 | s64 new_size; | |
1254 | struct inode *vi = VFS_I(ni); | |
1255 | ntfs_volume *vol = ni->vol; | |
1256 | ntfs_inode *base_ni; | |
1257 | MFT_RECORD *m; | |
1258 | ATTR_RECORD *a; | |
1259 | ntfs_attr_search_ctx *ctx; | |
1260 | struct page *page; | |
1261 | runlist_element *rl; | |
1262 | u8 *kaddr; | |
1263 | unsigned long flags; | |
1264 | int mp_size, mp_ofs, name_ofs, arec_size, err, err2; | |
1265 | u32 attr_size; | |
1266 | u8 old_res_attr_flags; | |
1267 | ||
1268 | /* Check that the attribute is allowed to be non-resident. */ | |
1269 | err = ntfs_attr_can_be_non_resident(vol, ni->type); | |
1270 | if (unlikely(err)) { | |
1271 | if (err == -EPERM) | |
1272 | ntfs_debug("Attribute is not allowed to be " | |
1273 | "non-resident."); | |
1274 | else | |
1275 | ntfs_debug("Attribute not defined on the NTFS " | |
1276 | "volume!"); | |
1277 | return err; | |
1278 | } | |
1279 | /* | |
1280 | * The size needs to be aligned to a cluster boundary for allocation | |
1281 | * purposes. | |
1282 | */ | |
1283 | new_size = (i_size_read(vi) + vol->cluster_size - 1) & | |
1284 | ~(vol->cluster_size - 1); | |
1285 | if (new_size > 0) { | |
1286 | /* | |
1287 | * Will need the page later and since the page lock nests | |
1288 | * outside all ntfs locks, we need to get the page now. | |
1289 | */ | |
1290 | page = find_or_create_page(vi->i_mapping, 0, | |
1291 | mapping_gfp_mask(vi->i_mapping)); | |
1292 | if (unlikely(!page)) | |
1293 | return -ENOMEM; | |
1294 | /* Start by allocating clusters to hold the attribute value. */ | |
1295 | rl = ntfs_cluster_alloc(vol, 0, new_size >> | |
1296 | vol->cluster_size_bits, -1, DATA_ZONE); | |
1297 | if (IS_ERR(rl)) { | |
1298 | err = PTR_ERR(rl); | |
1299 | ntfs_debug("Failed to allocate cluster%s, error code " | |
1300 | "%i.\n", (new_size >> | |
1301 | vol->cluster_size_bits) > 1 ? "s" : "", | |
1302 | err); | |
1303 | goto page_err_out; | |
1304 | } | |
1305 | } else { | |
1306 | rl = NULL; | |
1307 | page = NULL; | |
1308 | } | |
1309 | /* Determine the size of the mapping pairs array. */ | |
1310 | mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0); | |
1311 | if (unlikely(mp_size < 0)) { | |
1312 | err = mp_size; | |
1313 | ntfs_debug("Failed to get size for mapping pairs array, error " | |
1314 | "code %i.", err); | |
1315 | goto rl_err_out; | |
1316 | } | |
1317 | down_write(&ni->runlist.lock); | |
1318 | if (!NInoAttr(ni)) | |
1319 | base_ni = ni; | |
1320 | else | |
1321 | base_ni = ni->ext.base_ntfs_ino; | |
1322 | m = map_mft_record(base_ni); | |
1323 | if (IS_ERR(m)) { | |
1324 | err = PTR_ERR(m); | |
1325 | m = NULL; | |
1326 | ctx = NULL; | |
1327 | goto err_out; | |
1328 | } | |
1329 | ctx = ntfs_attr_get_search_ctx(base_ni, m); | |
1330 | if (unlikely(!ctx)) { | |
1331 | err = -ENOMEM; | |
1332 | goto err_out; | |
1333 | } | |
1334 | err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, | |
1335 | CASE_SENSITIVE, 0, NULL, 0, ctx); | |
1336 | if (unlikely(err)) { | |
1337 | if (err == -ENOENT) | |
1338 | err = -EIO; | |
1339 | goto err_out; | |
1340 | } | |
1341 | m = ctx->mrec; | |
1342 | a = ctx->attr; | |
1343 | BUG_ON(NInoNonResident(ni)); | |
1344 | BUG_ON(a->non_resident); | |
1345 | /* | |
1346 | * Calculate new offsets for the name and the mapping pairs array. | |
1347 | * We assume the attribute is not compressed or sparse. | |
1348 | */ | |
1349 | name_ofs = (offsetof(ATTR_REC, | |
1350 | data.non_resident.compressed_size) + 7) & ~7; | |
1351 | mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7; | |
1352 | /* | |
1353 | * Determine the size of the resident part of the now non-resident | |
1354 | * attribute record. | |
1355 | */ | |
1356 | arec_size = (mp_ofs + mp_size + 7) & ~7; | |
1357 | /* | |
1358 | * If the page is not uptodate bring it uptodate by copying from the | |
1359 | * attribute value. | |
1360 | */ | |
1361 | attr_size = le32_to_cpu(a->data.resident.value_length); | |
1362 | BUG_ON(attr_size != i_size_read(vi)); | |
1363 | if (page && !PageUptodate(page)) { | |
1364 | kaddr = kmap_atomic(page, KM_USER0); | |
1365 | memcpy(kaddr, (u8*)a + | |
1366 | le16_to_cpu(a->data.resident.value_offset), | |
1367 | attr_size); | |
1368 | memset(kaddr + attr_size, 0, PAGE_CACHE_SIZE - attr_size); | |
1369 | kunmap_atomic(kaddr, KM_USER0); | |
1370 | flush_dcache_page(page); | |
1371 | SetPageUptodate(page); | |
1372 | } | |
1373 | /* Backup the attribute flag. */ | |
1374 | old_res_attr_flags = a->data.resident.flags; | |
1375 | /* Resize the resident part of the attribute record. */ | |
1376 | err = ntfs_attr_record_resize(m, a, arec_size); | |
1377 | if (unlikely(err)) | |
1378 | goto err_out; | |
1379 | /* Setup the in-memory attribute structure to be non-resident. */ | |
1380 | NInoSetNonResident(ni); | |
1381 | ni->runlist.rl = rl; | |
1382 | write_lock_irqsave(&ni->size_lock, flags); | |
1383 | ni->allocated_size = new_size; | |
1384 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1385 | /* | |
1386 | * FIXME: For now just clear all of these as we do not support them | |
1387 | * when writing. | |
1388 | */ | |
1389 | NInoClearCompressed(ni); | |
1390 | NInoClearSparse(ni); | |
1391 | NInoClearEncrypted(ni); | |
1392 | /* | |
1393 | * Convert the resident part of the attribute record to describe a | |
1394 | * non-resident attribute. | |
1395 | */ | |
1396 | a->non_resident = 1; | |
1397 | /* Move the attribute name if it exists and update the offset. */ | |
1398 | if (a->name_length) | |
1399 | memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset), | |
1400 | a->name_length * sizeof(ntfschar)); | |
1401 | a->name_offset = cpu_to_le16(name_ofs); | |
1402 | /* Update the flags to match the in-memory ones. */ | |
1403 | a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE | | |
1404 | ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK)); | |
1405 | /* Setup the fields specific to non-resident attributes. */ | |
1406 | a->data.non_resident.lowest_vcn = 0; | |
1407 | a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >> | |
1408 | vol->cluster_size_bits); | |
1409 | a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs); | |
1410 | a->data.non_resident.compression_unit = 0; | |
1411 | memset(&a->data.non_resident.reserved, 0, | |
1412 | sizeof(a->data.non_resident.reserved)); | |
1413 | a->data.non_resident.allocated_size = cpu_to_sle64(new_size); | |
1414 | a->data.non_resident.data_size = | |
1415 | a->data.non_resident.initialized_size = | |
1416 | cpu_to_sle64(attr_size); | |
1417 | /* Generate the mapping pairs array into the attribute record. */ | |
1418 | err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs, | |
1419 | arec_size - mp_ofs, rl, 0, NULL); | |
1420 | if (unlikely(err)) { | |
1421 | ntfs_debug("Failed to build mapping pairs, error code %i.", | |
1422 | err); | |
1423 | goto undo_err_out; | |
1424 | } | |
1425 | /* Mark the mft record dirty, so it gets written back. */ | |
1426 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1427 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1428 | ntfs_attr_put_search_ctx(ctx); | |
1429 | unmap_mft_record(base_ni); | |
1430 | up_write(&ni->runlist.lock); | |
1431 | if (page) { | |
1432 | set_page_dirty(page); | |
1433 | unlock_page(page); | |
1434 | page_cache_release(page); | |
1435 | } | |
1436 | ntfs_debug("Done."); | |
1437 | return 0; | |
1438 | undo_err_out: | |
1439 | /* Convert the attribute back into a resident attribute. */ | |
1440 | a->non_resident = 0; | |
1441 | /* Move the attribute name if it exists and update the offset. */ | |
1442 | name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) + | |
1443 | sizeof(a->data.resident.reserved) + 7) & ~7; | |
1444 | if (a->name_length) | |
1445 | memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset), | |
1446 | a->name_length * sizeof(ntfschar)); | |
1447 | mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7; | |
1448 | a->name_offset = cpu_to_le16(name_ofs); | |
1449 | arec_size = (mp_ofs + attr_size + 7) & ~7; | |
1450 | /* Resize the resident part of the attribute record. */ | |
1451 | err2 = ntfs_attr_record_resize(m, a, arec_size); | |
1452 | if (unlikely(err2)) { | |
1453 | /* | |
1454 | * This cannot happen (well if memory corruption is at work it | |
1455 | * could happen in theory), but deal with it as well as we can. | |
1456 | * If the old size is too small, truncate the attribute, | |
1457 | * otherwise simply give it a larger allocated size. | |
1458 | * FIXME: Should check whether chkdsk complains when the | |
1459 | * allocated size is much bigger than the resident value size. | |
1460 | */ | |
1461 | arec_size = le32_to_cpu(a->length); | |
1462 | if ((mp_ofs + attr_size) > arec_size) { | |
1463 | err2 = attr_size; | |
1464 | attr_size = arec_size - mp_ofs; | |
1465 | ntfs_error(vol->sb, "Failed to undo partial resident " | |
1466 | "to non-resident attribute " | |
1467 | "conversion. Truncating inode 0x%lx, " | |
1468 | "attribute type 0x%x from %i bytes to " | |
1469 | "%i bytes to maintain metadata " | |
1470 | "consistency. THIS MEANS YOU ARE " | |
1471 | "LOSING %i BYTES DATA FROM THIS %s.", | |
1472 | vi->i_ino, | |
1473 | (unsigned)le32_to_cpu(ni->type), | |
1474 | err2, attr_size, err2 - attr_size, | |
1475 | ((ni->type == AT_DATA) && | |
1476 | !ni->name_len) ? "FILE": "ATTRIBUTE"); | |
1477 | write_lock_irqsave(&ni->size_lock, flags); | |
1478 | ni->initialized_size = attr_size; | |
1479 | i_size_write(vi, attr_size); | |
1480 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1481 | } | |
1482 | } | |
1483 | /* Setup the fields specific to resident attributes. */ | |
1484 | a->data.resident.value_length = cpu_to_le32(attr_size); | |
1485 | a->data.resident.value_offset = cpu_to_le16(mp_ofs); | |
1486 | a->data.resident.flags = old_res_attr_flags; | |
1487 | memset(&a->data.resident.reserved, 0, | |
1488 | sizeof(a->data.resident.reserved)); | |
1489 | /* Copy the data from the page back to the attribute value. */ | |
1490 | if (page) { | |
1491 | kaddr = kmap_atomic(page, KM_USER0); | |
1492 | memcpy((u8*)a + mp_ofs, kaddr, attr_size); | |
1493 | kunmap_atomic(kaddr, KM_USER0); | |
1494 | } | |
1495 | /* Finally setup the ntfs inode appropriately. */ | |
1496 | write_lock_irqsave(&ni->size_lock, flags); | |
1497 | ni->allocated_size = arec_size - mp_ofs; | |
1498 | write_unlock_irqrestore(&ni->size_lock, flags); | |
1499 | NInoClearNonResident(ni); | |
1500 | /* Mark the mft record dirty, so it gets written back. */ | |
1501 | flush_dcache_mft_record_page(ctx->ntfs_ino); | |
1502 | mark_mft_record_dirty(ctx->ntfs_ino); | |
1503 | err_out: | |
1504 | if (ctx) | |
1505 | ntfs_attr_put_search_ctx(ctx); | |
1506 | if (m) | |
1507 | unmap_mft_record(base_ni); | |
1508 | ni->runlist.rl = NULL; | |
1509 | up_write(&ni->runlist.lock); | |
1510 | rl_err_out: | |
1511 | if (rl) { | |
1512 | if (ntfs_cluster_free_from_rl(vol, rl) < 0) { | |
1513 | ntfs_free(rl); | |
1514 | ntfs_error(vol->sb, "Failed to release allocated " | |
1515 | "cluster(s) in error code path. Run " | |
1516 | "chkdsk to recover the lost " | |
1517 | "cluster(s)."); | |
1518 | NVolSetErrors(vol); | |
1519 | } | |
1520 | page_err_out: | |
1521 | unlock_page(page); | |
1522 | page_cache_release(page); | |
1523 | } | |
1524 | if (err == -EINVAL) | |
1525 | err = -EIO; | |
1526 | return err; | |
1527 | } | |
1528 | ||
1da177e4 LT |
1529 | /** |
1530 | * ntfs_attr_set - fill (a part of) an attribute with a byte | |
1531 | * @ni: ntfs inode describing the attribute to fill | |
1532 | * @ofs: offset inside the attribute at which to start to fill | |
1533 | * @cnt: number of bytes to fill | |
1534 | * @val: the unsigned 8-bit value with which to fill the attribute | |
1535 | * | |
1536 | * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at | |
1537 | * byte offset @ofs inside the attribute with the constant byte @val. | |
1538 | * | |
1539 | * This function is effectively like memset() applied to an ntfs attribute. | |
da28438c AA |
1540 | * Note thie function actually only operates on the page cache pages belonging |
1541 | * to the ntfs attribute and it marks them dirty after doing the memset(). | |
1542 | * Thus it relies on the vm dirty page write code paths to cause the modified | |
1543 | * pages to be written to the mft record/disk. | |
1da177e4 LT |
1544 | * |
1545 | * Return 0 on success and -errno on error. An error code of -ESPIPE means | |
1546 | * that @ofs + @cnt were outside the end of the attribute and no write was | |
1547 | * performed. | |
1548 | */ | |
1549 | int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val) | |
1550 | { | |
1551 | ntfs_volume *vol = ni->vol; | |
1552 | struct address_space *mapping; | |
1553 | struct page *page; | |
1554 | u8 *kaddr; | |
1555 | pgoff_t idx, end; | |
1556 | unsigned int start_ofs, end_ofs, size; | |
1557 | ||
1558 | ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.", | |
1559 | (long long)ofs, (long long)cnt, val); | |
1560 | BUG_ON(ofs < 0); | |
1561 | BUG_ON(cnt < 0); | |
1562 | if (!cnt) | |
1563 | goto done; | |
1564 | mapping = VFS_I(ni)->i_mapping; | |
1565 | /* Work out the starting index and page offset. */ | |
1566 | idx = ofs >> PAGE_CACHE_SHIFT; | |
1567 | start_ofs = ofs & ~PAGE_CACHE_MASK; | |
1568 | /* Work out the ending index and page offset. */ | |
1569 | end = ofs + cnt; | |
1570 | end_ofs = end & ~PAGE_CACHE_MASK; | |
1571 | /* If the end is outside the inode size return -ESPIPE. */ | |
da28438c | 1572 | if (unlikely(end > i_size_read(VFS_I(ni)))) { |
1da177e4 LT |
1573 | ntfs_error(vol->sb, "Request exceeds end of attribute."); |
1574 | return -ESPIPE; | |
1575 | } | |
1576 | end >>= PAGE_CACHE_SHIFT; | |
1577 | /* If there is a first partial page, need to do it the slow way. */ | |
1578 | if (start_ofs) { | |
1579 | page = read_cache_page(mapping, idx, | |
1580 | (filler_t*)mapping->a_ops->readpage, NULL); | |
1581 | if (IS_ERR(page)) { | |
1582 | ntfs_error(vol->sb, "Failed to read first partial " | |
1583 | "page (sync error, index 0x%lx).", idx); | |
1584 | return PTR_ERR(page); | |
1585 | } | |
1586 | wait_on_page_locked(page); | |
1587 | if (unlikely(!PageUptodate(page))) { | |
1588 | ntfs_error(vol->sb, "Failed to read first partial page " | |
1589 | "(async error, index 0x%lx).", idx); | |
1590 | page_cache_release(page); | |
1591 | return PTR_ERR(page); | |
1592 | } | |
1593 | /* | |
1594 | * If the last page is the same as the first page, need to | |
1595 | * limit the write to the end offset. | |
1596 | */ | |
1597 | size = PAGE_CACHE_SIZE; | |
1598 | if (idx == end) | |
1599 | size = end_ofs; | |
1600 | kaddr = kmap_atomic(page, KM_USER0); | |
1601 | memset(kaddr + start_ofs, val, size - start_ofs); | |
1602 | flush_dcache_page(page); | |
1603 | kunmap_atomic(kaddr, KM_USER0); | |
1604 | set_page_dirty(page); | |
1605 | page_cache_release(page); | |
1606 | if (idx == end) | |
1607 | goto done; | |
1608 | idx++; | |
1609 | } | |
1610 | /* Do the whole pages the fast way. */ | |
1611 | for (; idx < end; idx++) { | |
1612 | /* Find or create the current page. (The page is locked.) */ | |
1613 | page = grab_cache_page(mapping, idx); | |
1614 | if (unlikely(!page)) { | |
1615 | ntfs_error(vol->sb, "Insufficient memory to grab " | |
1616 | "page (index 0x%lx).", idx); | |
1617 | return -ENOMEM; | |
1618 | } | |
1619 | kaddr = kmap_atomic(page, KM_USER0); | |
1620 | memset(kaddr, val, PAGE_CACHE_SIZE); | |
1621 | flush_dcache_page(page); | |
1622 | kunmap_atomic(kaddr, KM_USER0); | |
1623 | /* | |
1624 | * If the page has buffers, mark them uptodate since buffer | |
1625 | * state and not page state is definitive in 2.6 kernels. | |
1626 | */ | |
1627 | if (page_has_buffers(page)) { | |
1628 | struct buffer_head *bh, *head; | |
1629 | ||
1630 | bh = head = page_buffers(page); | |
1631 | do { | |
1632 | set_buffer_uptodate(bh); | |
1633 | } while ((bh = bh->b_this_page) != head); | |
1634 | } | |
1635 | /* Now that buffers are uptodate, set the page uptodate, too. */ | |
1636 | SetPageUptodate(page); | |
1637 | /* | |
1638 | * Set the page and all its buffers dirty and mark the inode | |
1639 | * dirty, too. The VM will write the page later on. | |
1640 | */ | |
1641 | set_page_dirty(page); | |
1642 | /* Finally unlock and release the page. */ | |
1643 | unlock_page(page); | |
1644 | page_cache_release(page); | |
1645 | } | |
1646 | /* If there is a last partial page, need to do it the slow way. */ | |
1647 | if (end_ofs) { | |
1648 | page = read_cache_page(mapping, idx, | |
1649 | (filler_t*)mapping->a_ops->readpage, NULL); | |
1650 | if (IS_ERR(page)) { | |
1651 | ntfs_error(vol->sb, "Failed to read last partial page " | |
1652 | "(sync error, index 0x%lx).", idx); | |
1653 | return PTR_ERR(page); | |
1654 | } | |
1655 | wait_on_page_locked(page); | |
1656 | if (unlikely(!PageUptodate(page))) { | |
1657 | ntfs_error(vol->sb, "Failed to read last partial page " | |
1658 | "(async error, index 0x%lx).", idx); | |
1659 | page_cache_release(page); | |
1660 | return PTR_ERR(page); | |
1661 | } | |
1662 | kaddr = kmap_atomic(page, KM_USER0); | |
1663 | memset(kaddr, val, end_ofs); | |
1664 | flush_dcache_page(page); | |
1665 | kunmap_atomic(kaddr, KM_USER0); | |
1666 | set_page_dirty(page); | |
1667 | page_cache_release(page); | |
1668 | } | |
1669 | done: | |
1670 | ntfs_debug("Done."); | |
1671 | return 0; | |
1672 | } |