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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project.
4 *
5 * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
6 * Copyright (c) 2002 Richard Russon
7 */
8
9#include <linux/buffer_head.h>
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/swap.h>
13#include <linux/writeback.h>
14
15#include "attrib.h"
16#include "debug.h"
17#include "layout.h"
18#include "lcnalloc.h"
19#include "malloc.h"
20#include "mft.h"
21#include "ntfs.h"
22#include "types.h"
23
24/**
25 * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode
26 * @ni: ntfs inode for which to map (part of) a runlist
27 * @vcn: map runlist part containing this vcn
28 * @ctx: active attribute search context if present or NULL if not
29 *
30 * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
31 *
32 * If @ctx is specified, it is an active search context of @ni and its base mft
33 * record. This is needed when ntfs_map_runlist_nolock() encounters unmapped
34 * runlist fragments and allows their mapping. If you do not have the mft
35 * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock()
36 * will perform the necessary mapping and unmapping.
37 *
38 * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and
39 * restores it before returning. Thus, @ctx will be left pointing to the same
40 * attribute on return as on entry. However, the actual pointers in @ctx may
41 * point to different memory locations on return, so you must remember to reset
42 * any cached pointers from the @ctx, i.e. after the call to
43 * ntfs_map_runlist_nolock(), you will probably want to do:
44 * m = ctx->mrec;
45 * a = ctx->attr;
46 * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
47 * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
48 *
49 * Return 0 on success and -errno on error. There is one special error code
50 * which is not an error as such. This is -ENOENT. It means that @vcn is out
51 * of bounds of the runlist.
52 *
53 * Note the runlist can be NULL after this function returns if @vcn is zero and
54 * the attribute has zero allocated size, i.e. there simply is no runlist.
55 *
56 * WARNING: If @ctx is supplied, regardless of whether success or failure is
57 * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
58 * is no longer valid, i.e. you need to either call
59 * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
60 * In that case PTR_ERR(@ctx->mrec) will give you the error code for
61 * why the mapping of the old inode failed.
62 *
63 * Locking: - The runlist described by @ni must be locked for writing on entry
64 * and is locked on return. Note the runlist will be modified.
65 * - If @ctx is NULL, the base mft record of @ni must not be mapped on
66 * entry and it will be left unmapped on return.
67 * - If @ctx is not NULL, the base mft record must be mapped on entry
68 * and it will be left mapped on return.
69 */
70int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
71{
72 VCN end_vcn;
73 unsigned long flags;
74 ntfs_inode *base_ni;
75 MFT_RECORD *m;
76 ATTR_RECORD *a;
77 runlist_element *rl;
78 struct page *put_this_page = NULL;
79 int err = 0;
80 bool ctx_is_temporary, ctx_needs_reset;
81 ntfs_attr_search_ctx old_ctx = { NULL, };
82
83 ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
84 (unsigned long long)vcn);
85 if (!NInoAttr(ni))
86 base_ni = ni;
87 else
88 base_ni = ni->ext.base_ntfs_ino;
89 if (!ctx) {
90 ctx_is_temporary = ctx_needs_reset = true;
91 m = map_mft_record(base_ni);
92 if (IS_ERR(m))
93 return PTR_ERR(m);
94 ctx = ntfs_attr_get_search_ctx(base_ni, m);
95 if (unlikely(!ctx)) {
96 err = -ENOMEM;
97 goto err_out;
98 }
99 } else {
100 VCN allocated_size_vcn;
101
102 BUG_ON(IS_ERR(ctx->mrec));
103 a = ctx->attr;
104 BUG_ON(!a->non_resident);
105 ctx_is_temporary = false;
106 end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
107 read_lock_irqsave(&ni->size_lock, flags);
108 allocated_size_vcn = ni->allocated_size >>
109 ni->vol->cluster_size_bits;
110 read_unlock_irqrestore(&ni->size_lock, flags);
111 if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
112 end_vcn = allocated_size_vcn - 1;
113 /*
114 * If we already have the attribute extent containing @vcn in
115 * @ctx, no need to look it up again. We slightly cheat in
116 * that if vcn exceeds the allocated size, we will refuse to
117 * map the runlist below, so there is definitely no need to get
118 * the right attribute extent.
119 */
120 if (vcn >= allocated_size_vcn || (a->type == ni->type &&
121 a->name_length == ni->name_len &&
122 !memcmp((u8*)a + le16_to_cpu(a->name_offset),
123 ni->name, ni->name_len) &&
124 sle64_to_cpu(a->data.non_resident.lowest_vcn)
125 <= vcn && end_vcn >= vcn))
126 ctx_needs_reset = false;
127 else {
128 /* Save the old search context. */
129 old_ctx = *ctx;
130 /*
131 * If the currently mapped (extent) inode is not the
132 * base inode we will unmap it when we reinitialize the
133 * search context which means we need to get a
134 * reference to the page containing the mapped mft
135 * record so we do not accidentally drop changes to the
136 * mft record when it has not been marked dirty yet.
137 */
138 if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
139 old_ctx.base_ntfs_ino) {
140 put_this_page = old_ctx.ntfs_ino->page;
141 get_page(put_this_page);
142 }
143 /*
144 * Reinitialize the search context so we can lookup the
145 * needed attribute extent.
146 */
147 ntfs_attr_reinit_search_ctx(ctx);
148 ctx_needs_reset = true;
149 }
150 }
151 if (ctx_needs_reset) {
152 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
153 CASE_SENSITIVE, vcn, NULL, 0, ctx);
154 if (unlikely(err)) {
155 if (err == -ENOENT)
156 err = -EIO;
157 goto err_out;
158 }
159 BUG_ON(!ctx->attr->non_resident);
160 }
161 a = ctx->attr;
162 /*
163 * Only decompress the mapping pairs if @vcn is inside it. Otherwise
164 * we get into problems when we try to map an out of bounds vcn because
165 * we then try to map the already mapped runlist fragment and
166 * ntfs_mapping_pairs_decompress() fails.
167 */
168 end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
169 if (unlikely(vcn && vcn >= end_vcn)) {
170 err = -ENOENT;
171 goto err_out;
172 }
173 rl = ntfs_mapping_pairs_decompress(ni->vol, a, ni->runlist.rl);
174 if (IS_ERR(rl))
175 err = PTR_ERR(rl);
176 else
177 ni->runlist.rl = rl;
178err_out:
179 if (ctx_is_temporary) {
180 if (likely(ctx))
181 ntfs_attr_put_search_ctx(ctx);
182 unmap_mft_record(base_ni);
183 } else if (ctx_needs_reset) {
184 /*
185 * If there is no attribute list, restoring the search context
186 * is accomplished simply by copying the saved context back over
187 * the caller supplied context. If there is an attribute list,
188 * things are more complicated as we need to deal with mapping
189 * of mft records and resulting potential changes in pointers.
190 */
191 if (NInoAttrList(base_ni)) {
192 /*
193 * If the currently mapped (extent) inode is not the
194 * one we had before, we need to unmap it and map the
195 * old one.
196 */
197 if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
198 /*
199 * If the currently mapped inode is not the
200 * base inode, unmap it.
201 */
202 if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
203 ctx->base_ntfs_ino) {
204 unmap_extent_mft_record(ctx->ntfs_ino);
205 ctx->mrec = ctx->base_mrec;
206 BUG_ON(!ctx->mrec);
207 }
208 /*
209 * If the old mapped inode is not the base
210 * inode, map it.
211 */
212 if (old_ctx.base_ntfs_ino &&
213 old_ctx.ntfs_ino !=
214 old_ctx.base_ntfs_ino) {
215retry_map:
216 ctx->mrec = map_mft_record(
217 old_ctx.ntfs_ino);
218 /*
219 * Something bad has happened. If out
220 * of memory retry till it succeeds.
221 * Any other errors are fatal and we
222 * return the error code in ctx->mrec.
223 * Let the caller deal with it... We
224 * just need to fudge things so the
225 * caller can reinit and/or put the
226 * search context safely.
227 */
228 if (IS_ERR(ctx->mrec)) {
229 if (PTR_ERR(ctx->mrec) ==
230 -ENOMEM) {
231 schedule();
232 goto retry_map;
233 } else
234 old_ctx.ntfs_ino =
235 old_ctx.
236 base_ntfs_ino;
237 }
238 }
239 }
240 /* Update the changed pointers in the saved context. */
241 if (ctx->mrec != old_ctx.mrec) {
242 if (!IS_ERR(ctx->mrec))
243 old_ctx.attr = (ATTR_RECORD*)(
244 (u8*)ctx->mrec +
245 ((u8*)old_ctx.attr -
246 (u8*)old_ctx.mrec));
247 old_ctx.mrec = ctx->mrec;
248 }
249 }
250 /* Restore the search context to the saved one. */
251 *ctx = old_ctx;
252 /*
253 * We drop the reference on the page we took earlier. In the
254 * case that IS_ERR(ctx->mrec) is true this means we might lose
255 * some changes to the mft record that had been made between
256 * the last time it was marked dirty/written out and now. This
257 * at this stage is not a problem as the mapping error is fatal
258 * enough that the mft record cannot be written out anyway and
259 * the caller is very likely to shutdown the whole inode
260 * immediately and mark the volume dirty for chkdsk to pick up
261 * the pieces anyway.
262 */
263 if (put_this_page)
264 put_page(put_this_page);
265 }
266 return err;
267}
268
269/**
270 * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode
271 * @ni: ntfs inode for which to map (part of) a runlist
272 * @vcn: map runlist part containing this vcn
273 *
274 * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
275 *
276 * Return 0 on success and -errno on error. There is one special error code
277 * which is not an error as such. This is -ENOENT. It means that @vcn is out
278 * of bounds of the runlist.
279 *
280 * Locking: - The runlist must be unlocked on entry and is unlocked on return.
281 * - This function takes the runlist lock for writing and may modify
282 * the runlist.
283 */
284int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
285{
286 int err = 0;
287
288 down_write(&ni->runlist.lock);
289 /* Make sure someone else didn't do the work while we were sleeping. */
290 if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
291 LCN_RL_NOT_MAPPED))
292 err = ntfs_map_runlist_nolock(ni, vcn, NULL);
293 up_write(&ni->runlist.lock);
294 return err;
295}
296
297/**
298 * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode
299 * @ni: ntfs inode of the attribute whose runlist to search
300 * @vcn: vcn to convert
301 * @write_locked: true if the runlist is locked for writing
302 *
303 * Find the virtual cluster number @vcn in the runlist of the ntfs attribute
304 * described by the ntfs inode @ni and return the corresponding logical cluster
305 * number (lcn).
306 *
307 * If the @vcn is not mapped yet, the attempt is made to map the attribute
308 * extent containing the @vcn and the vcn to lcn conversion is retried.
309 *
310 * If @write_locked is true the caller has locked the runlist for writing and
311 * if false for reading.
312 *
313 * Since lcns must be >= 0, we use negative return codes with special meaning:
314 *
315 * Return code Meaning / Description
316 * ==========================================
317 * LCN_HOLE Hole / not allocated on disk.
318 * LCN_ENOENT There is no such vcn in the runlist, i.e. @vcn is out of bounds.
319 * LCN_ENOMEM Not enough memory to map runlist.
320 * LCN_EIO Critical error (runlist/file is corrupt, i/o error, etc).
321 *
322 * Locking: - The runlist must be locked on entry and is left locked on return.
323 * - If @write_locked is 'false', i.e. the runlist is locked for reading,
324 * the lock may be dropped inside the function so you cannot rely on
325 * the runlist still being the same when this function returns.
326 */
327LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
328 const bool write_locked)
329{
330 LCN lcn;
331 unsigned long flags;
332 bool is_retry = false;
333
334 BUG_ON(!ni);
335 ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
336 ni->mft_no, (unsigned long long)vcn,
337 write_locked ? "write" : "read");
338 BUG_ON(!NInoNonResident(ni));
339 BUG_ON(vcn < 0);
340 if (!ni->runlist.rl) {
341 read_lock_irqsave(&ni->size_lock, flags);
342 if (!ni->allocated_size) {
343 read_unlock_irqrestore(&ni->size_lock, flags);
344 return LCN_ENOENT;
345 }
346 read_unlock_irqrestore(&ni->size_lock, flags);
347 }
348retry_remap:
349 /* Convert vcn to lcn. If that fails map the runlist and retry once. */
350 lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
351 if (likely(lcn >= LCN_HOLE)) {
352 ntfs_debug("Done, lcn 0x%llx.", (long long)lcn);
353 return lcn;
354 }
355 if (lcn != LCN_RL_NOT_MAPPED) {
356 if (lcn != LCN_ENOENT)
357 lcn = LCN_EIO;
358 } else if (!is_retry) {
359 int err;
360
361 if (!write_locked) {
362 up_read(&ni->runlist.lock);
363 down_write(&ni->runlist.lock);
364 if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=
365 LCN_RL_NOT_MAPPED)) {
366 up_write(&ni->runlist.lock);
367 down_read(&ni->runlist.lock);
368 goto retry_remap;
369 }
370 }
371 err = ntfs_map_runlist_nolock(ni, vcn, NULL);
372 if (!write_locked) {
373 up_write(&ni->runlist.lock);
374 down_read(&ni->runlist.lock);
375 }
376 if (likely(!err)) {
377 is_retry = true;
378 goto retry_remap;
379 }
380 if (err == -ENOENT)
381 lcn = LCN_ENOENT;
382 else if (err == -ENOMEM)
383 lcn = LCN_ENOMEM;
384 else
385 lcn = LCN_EIO;
386 }
387 if (lcn != LCN_ENOENT)
388 ntfs_error(ni->vol->sb, "Failed with error code %lli.",
389 (long long)lcn);
390 return lcn;
391}
392
393/**
394 * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
395 * @ni: ntfs inode describing the runlist to search
396 * @vcn: vcn to find
397 * @ctx: active attribute search context if present or NULL if not
398 *
399 * Find the virtual cluster number @vcn in the runlist described by the ntfs
400 * inode @ni and return the address of the runlist element containing the @vcn.
401 *
402 * If the @vcn is not mapped yet, the attempt is made to map the attribute
403 * extent containing the @vcn and the vcn to lcn conversion is retried.
404 *
405 * If @ctx is specified, it is an active search context of @ni and its base mft
406 * record. This is needed when ntfs_attr_find_vcn_nolock() encounters unmapped
407 * runlist fragments and allows their mapping. If you do not have the mft
408 * record mapped, you can specify @ctx as NULL and ntfs_attr_find_vcn_nolock()
409 * will perform the necessary mapping and unmapping.
410 *
411 * Note, ntfs_attr_find_vcn_nolock() saves the state of @ctx on entry and
412 * restores it before returning. Thus, @ctx will be left pointing to the same
413 * attribute on return as on entry. However, the actual pointers in @ctx may
414 * point to different memory locations on return, so you must remember to reset
415 * any cached pointers from the @ctx, i.e. after the call to
416 * ntfs_attr_find_vcn_nolock(), you will probably want to do:
417 * m = ctx->mrec;
418 * a = ctx->attr;
419 * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
420 * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
421 * Note you need to distinguish between the lcn of the returned runlist element
422 * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on
423 * read and allocate clusters on write.
424 *
425 * Return the runlist element containing the @vcn on success and
426 * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR()
427 * to decide if the return is success or failure and PTR_ERR() to get to the
428 * error code if IS_ERR() is true.
429 *
430 * The possible error return codes are:
431 * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds.
432 * -ENOMEM - Not enough memory to map runlist.
433 * -EIO - Critical error (runlist/file is corrupt, i/o error, etc).
434 *
435 * WARNING: If @ctx is supplied, regardless of whether success or failure is
436 * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
437 * is no longer valid, i.e. you need to either call
438 * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
439 * In that case PTR_ERR(@ctx->mrec) will give you the error code for
440 * why the mapping of the old inode failed.
441 *
442 * Locking: - The runlist described by @ni must be locked for writing on entry
443 * and is locked on return. Note the runlist may be modified when
444 * needed runlist fragments need to be mapped.
445 * - If @ctx is NULL, the base mft record of @ni must not be mapped on
446 * entry and it will be left unmapped on return.
447 * - If @ctx is not NULL, the base mft record must be mapped on entry
448 * and it will be left mapped on return.
449 */
450runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
451 ntfs_attr_search_ctx *ctx)
452{
453 unsigned long flags;
454 runlist_element *rl;
455 int err = 0;
456 bool is_retry = false;
457
458 BUG_ON(!ni);
459 ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, with%s ctx.",
460 ni->mft_no, (unsigned long long)vcn, ctx ? "" : "out");
461 BUG_ON(!NInoNonResident(ni));
462 BUG_ON(vcn < 0);
463 if (!ni->runlist.rl) {
464 read_lock_irqsave(&ni->size_lock, flags);
465 if (!ni->allocated_size) {
466 read_unlock_irqrestore(&ni->size_lock, flags);
467 return ERR_PTR(-ENOENT);
468 }
469 read_unlock_irqrestore(&ni->size_lock, flags);
470 }
471retry_remap:
472 rl = ni->runlist.rl;
473 if (likely(rl && vcn >= rl[0].vcn)) {
474 while (likely(rl->length)) {
475 if (unlikely(vcn < rl[1].vcn)) {
476 if (likely(rl->lcn >= LCN_HOLE)) {
477 ntfs_debug("Done.");
478 return rl;
479 }
480 break;
481 }
482 rl++;
483 }
484 if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) {
485 if (likely(rl->lcn == LCN_ENOENT))
486 err = -ENOENT;
487 else
488 err = -EIO;
489 }
490 }
491 if (!err && !is_retry) {
492 /*
493 * If the search context is invalid we cannot map the unmapped
494 * region.
495 */
496 if (IS_ERR(ctx->mrec))
497 err = PTR_ERR(ctx->mrec);
498 else {
499 /*
500 * The @vcn is in an unmapped region, map the runlist
501 * and retry.
502 */
503 err = ntfs_map_runlist_nolock(ni, vcn, ctx);
504 if (likely(!err)) {
505 is_retry = true;
506 goto retry_remap;
507 }
508 }
509 if (err == -EINVAL)
510 err = -EIO;
511 } else if (!err)
512 err = -EIO;
513 if (err != -ENOENT)
514 ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
515 return ERR_PTR(err);
516}
517
518/**
519 * ntfs_attr_find - find (next) attribute in mft record
520 * @type: attribute type to find
521 * @name: attribute name to find (optional, i.e. NULL means don't care)
522 * @name_len: attribute name length (only needed if @name present)
523 * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
524 * @val: attribute value to find (optional, resident attributes only)
525 * @val_len: attribute value length
526 * @ctx: search context with mft record and attribute to search from
527 *
528 * You should not need to call this function directly. Use ntfs_attr_lookup()
529 * instead.
530 *
531 * ntfs_attr_find() takes a search context @ctx as parameter and searches the
532 * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an
533 * attribute of @type, optionally @name and @val.
534 *
535 * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
536 * point to the found attribute.
537 *
538 * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
539 * @ctx->attr will point to the attribute before which the attribute being
540 * searched for would need to be inserted if such an action were to be desired.
541 *
542 * On actual error, ntfs_attr_find() returns -EIO. In this case @ctx->attr is
543 * undefined and in particular do not rely on it not changing.
544 *
545 * If @ctx->is_first is 'true', the search begins with @ctx->attr itself. If it
546 * is 'false', the search begins after @ctx->attr.
547 *
548 * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and
549 * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record
550 * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at
551 * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case
552 * sensitive. When @name is present, @name_len is the @name length in Unicode
553 * characters.
554 *
555 * If @name is not present (NULL), we assume that the unnamed attribute is
556 * being searched for.
557 *
558 * Finally, the resident attribute value @val is looked for, if present. If
559 * @val is not present (NULL), @val_len is ignored.
560 *
561 * ntfs_attr_find() only searches the specified mft record and it ignores the
562 * presence of an attribute list attribute (unless it is the one being searched
563 * for, obviously). If you need to take attribute lists into consideration,
564 * use ntfs_attr_lookup() instead (see below). This also means that you cannot
565 * use ntfs_attr_find() to search for extent records of non-resident
566 * attributes, as extents with lowest_vcn != 0 are usually described by the
567 * attribute list attribute only. - Note that it is possible that the first
568 * extent is only in the attribute list while the last extent is in the base
569 * mft record, so do not rely on being able to find the first extent in the
570 * base mft record.
571 *
572 * Warning: Never use @val when looking for attribute types which can be
573 * non-resident as this most likely will result in a crash!
574 */
575static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
576 const u32 name_len, const IGNORE_CASE_BOOL ic,
577 const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
578{
579 ATTR_RECORD *a;
580 ntfs_volume *vol = ctx->ntfs_ino->vol;
581 ntfschar *upcase = vol->upcase;
582 u32 upcase_len = vol->upcase_len;
583
584 /*
585 * Iterate over attributes in mft record starting at @ctx->attr, or the
586 * attribute following that, if @ctx->is_first is 'true'.
587 */
588 if (ctx->is_first) {
589 a = ctx->attr;
590 ctx->is_first = false;
591 } else
592 a = (ATTR_RECORD*)((u8*)ctx->attr +
593 le32_to_cpu(ctx->attr->length));
594 for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) {
595 u8 *mrec_end = (u8 *)ctx->mrec +
596 le32_to_cpu(ctx->mrec->bytes_allocated);
597 u8 *name_end;
598
599 /* check whether ATTR_RECORD wrap */
600 if ((u8 *)a < (u8 *)ctx->mrec)
601 break;
602
603 /* check whether Attribute Record Header is within bounds */
604 if ((u8 *)a > mrec_end ||
605 (u8 *)a + sizeof(ATTR_RECORD) > mrec_end)
606 break;
607
608 /* check whether ATTR_RECORD's name is within bounds */
609 name_end = (u8 *)a + le16_to_cpu(a->name_offset) +
610 a->name_length * sizeof(ntfschar);
611 if (name_end > mrec_end)
612 break;
613
614 ctx->attr = a;
615 if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
616 a->type == AT_END))
617 return -ENOENT;
618 if (unlikely(!a->length))
619 break;
620
621 /* check whether ATTR_RECORD's length wrap */
622 if ((u8 *)a + le32_to_cpu(a->length) < (u8 *)a)
623 break;
624 /* check whether ATTR_RECORD's length is within bounds */
625 if ((u8 *)a + le32_to_cpu(a->length) > mrec_end)
626 break;
627
628 if (a->type != type)
629 continue;
630 /*
631 * If @name is present, compare the two names. If @name is
632 * missing, assume we want an unnamed attribute.
633 */
634 if (!name) {
635 /* The search failed if the found attribute is named. */
636 if (a->name_length)
637 return -ENOENT;
638 } else if (!ntfs_are_names_equal(name, name_len,
639 (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)),
640 a->name_length, ic, upcase, upcase_len)) {
641 register int rc;
642
643 rc = ntfs_collate_names(name, name_len,
644 (ntfschar*)((u8*)a +
645 le16_to_cpu(a->name_offset)),
646 a->name_length, 1, IGNORE_CASE,
647 upcase, upcase_len);
648 /*
649 * If @name collates before a->name, there is no
650 * matching attribute.
651 */
652 if (rc == -1)
653 return -ENOENT;
654 /* If the strings are not equal, continue search. */
655 if (rc)
656 continue;
657 rc = ntfs_collate_names(name, name_len,
658 (ntfschar*)((u8*)a +
659 le16_to_cpu(a->name_offset)),
660 a->name_length, 1, CASE_SENSITIVE,
661 upcase, upcase_len);
662 if (rc == -1)
663 return -ENOENT;
664 if (rc)
665 continue;
666 }
667 /*
668 * The names match or @name not present and attribute is
669 * unnamed. If no @val specified, we have found the attribute
670 * and are done.
671 */
672 if (!val)
673 return 0;
674 /* @val is present; compare values. */
675 else {
676 register int rc;
677
678 rc = memcmp(val, (u8*)a + le16_to_cpu(
679 a->data.resident.value_offset),
680 min_t(u32, val_len, le32_to_cpu(
681 a->data.resident.value_length)));
682 /*
683 * If @val collates before the current attribute's
684 * value, there is no matching attribute.
685 */
686 if (!rc) {
687 register u32 avl;
688
689 avl = le32_to_cpu(
690 a->data.resident.value_length);
691 if (val_len == avl)
692 return 0;
693 if (val_len < avl)
694 return -ENOENT;
695 } else if (rc < 0)
696 return -ENOENT;
697 }
698 }
699 ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk.");
700 NVolSetErrors(vol);
701 return -EIO;
702}
703
704/**
705 * load_attribute_list - load an attribute list into memory
706 * @vol: ntfs volume from which to read
707 * @runlist: runlist of the attribute list
708 * @al_start: destination buffer
709 * @size: size of the destination buffer in bytes
710 * @initialized_size: initialized size of the attribute list
711 *
712 * Walk the runlist @runlist and load all clusters from it copying them into
713 * the linear buffer @al. The maximum number of bytes copied to @al is @size
714 * bytes. Note, @size does not need to be a multiple of the cluster size. If
715 * @initialized_size is less than @size, the region in @al between
716 * @initialized_size and @size will be zeroed and not read from disk.
717 *
718 * Return 0 on success or -errno on error.
719 */
720int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
721 const s64 size, const s64 initialized_size)
722{
723 LCN lcn;
724 u8 *al = al_start;
725 u8 *al_end = al + initialized_size;
726 runlist_element *rl;
727 struct buffer_head *bh;
728 struct super_block *sb;
729 unsigned long block_size;
730 unsigned long block, max_block;
731 int err = 0;
732 unsigned char block_size_bits;
733
734 ntfs_debug("Entering.");
735 if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 ||
736 initialized_size > size)
737 return -EINVAL;
738 if (!initialized_size) {
739 memset(al, 0, size);
740 return 0;
741 }
742 sb = vol->sb;
743 block_size = sb->s_blocksize;
744 block_size_bits = sb->s_blocksize_bits;
745 down_read(&runlist->lock);
746 rl = runlist->rl;
747 if (!rl) {
748 ntfs_error(sb, "Cannot read attribute list since runlist is "
749 "missing.");
750 goto err_out;
751 }
752 /* Read all clusters specified by the runlist one run at a time. */
753 while (rl->length) {
754 lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);
755 ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.",
756 (unsigned long long)rl->vcn,
757 (unsigned long long)lcn);
758 /* The attribute list cannot be sparse. */
759 if (lcn < 0) {
760 ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed. Cannot "
761 "read attribute list.");
762 goto err_out;
763 }
764 block = lcn << vol->cluster_size_bits >> block_size_bits;
765 /* Read the run from device in chunks of block_size bytes. */
766 max_block = block + (rl->length << vol->cluster_size_bits >>
767 block_size_bits);
768 ntfs_debug("max_block = 0x%lx.", max_block);
769 do {
770 ntfs_debug("Reading block = 0x%lx.", block);
771 bh = sb_bread(sb, block);
772 if (!bh) {
773 ntfs_error(sb, "sb_bread() failed. Cannot "
774 "read attribute list.");
775 goto err_out;
776 }
777 if (al + block_size >= al_end)
778 goto do_final;
779 memcpy(al, bh->b_data, block_size);
780 brelse(bh);
781 al += block_size;
782 } while (++block < max_block);
783 rl++;
784 }
785 if (initialized_size < size) {
786initialize:
787 memset(al_start + initialized_size, 0, size - initialized_size);
788 }
789done:
790 up_read(&runlist->lock);
791 return err;
792do_final:
793 if (al < al_end) {
794 /*
795 * Partial block.
796 *
797 * Note: The attribute list can be smaller than its allocation
798 * by multiple clusters. This has been encountered by at least
799 * two people running Windows XP, thus we cannot do any
800 * truncation sanity checking here. (AIA)
801 */
802 memcpy(al, bh->b_data, al_end - al);
803 brelse(bh);
804 if (initialized_size < size)
805 goto initialize;
806 goto done;
807 }
808 brelse(bh);
809 /* Real overflow! */
810 ntfs_error(sb, "Attribute list buffer overflow. Read attribute list "
811 "is truncated.");
812err_out:
813 err = -EIO;
814 goto done;
815}
816
817/**
818 * ntfs_external_attr_find - find an attribute in the attribute list of an inode
819 * @type: attribute type to find
820 * @name: attribute name to find (optional, i.e. NULL means don't care)
821 * @name_len: attribute name length (only needed if @name present)
822 * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
823 * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
824 * @val: attribute value to find (optional, resident attributes only)
825 * @val_len: attribute value length
826 * @ctx: search context with mft record and attribute to search from
827 *
828 * You should not need to call this function directly. Use ntfs_attr_lookup()
829 * instead.
830 *
831 * Find an attribute by searching the attribute list for the corresponding
832 * attribute list entry. Having found the entry, map the mft record if the
833 * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
834 * in there and return it.
835 *
836 * On first search @ctx->ntfs_ino must be the base mft record and @ctx must
837 * have been obtained from a call to ntfs_attr_get_search_ctx(). On subsequent
838 * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is
839 * then the base inode).
840 *
841 * After finishing with the attribute/mft record you need to call
842 * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
843 * mapped inodes, etc).
844 *
845 * If the attribute is found, ntfs_external_attr_find() returns 0 and
846 * @ctx->attr will point to the found attribute. @ctx->mrec will point to the
847 * mft record in which @ctx->attr is located and @ctx->al_entry will point to
848 * the attribute list entry for the attribute.
849 *
850 * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
851 * @ctx->attr will point to the attribute in the base mft record before which
852 * the attribute being searched for would need to be inserted if such an action
853 * were to be desired. @ctx->mrec will point to the mft record in which
854 * @ctx->attr is located and @ctx->al_entry will point to the attribute list
855 * entry of the attribute before which the attribute being searched for would
856 * need to be inserted if such an action were to be desired.
857 *
858 * Thus to insert the not found attribute, one wants to add the attribute to
859 * @ctx->mrec (the base mft record) and if there is not enough space, the
860 * attribute should be placed in a newly allocated extent mft record. The
861 * attribute list entry for the inserted attribute should be inserted in the
862 * attribute list attribute at @ctx->al_entry.
863 *
864 * On actual error, ntfs_external_attr_find() returns -EIO. In this case
865 * @ctx->attr is undefined and in particular do not rely on it not changing.
866 */
867static int ntfs_external_attr_find(const ATTR_TYPE type,
868 const ntfschar *name, const u32 name_len,
869 const IGNORE_CASE_BOOL ic, const VCN lowest_vcn,
870 const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
871{
872 ntfs_inode *base_ni, *ni;
873 ntfs_volume *vol;
874 ATTR_LIST_ENTRY *al_entry, *next_al_entry;
875 u8 *al_start, *al_end;
876 ATTR_RECORD *a;
877 ntfschar *al_name;
878 u32 al_name_len;
879 int err = 0;
880 static const char *es = " Unmount and run chkdsk.";
881
882 ni = ctx->ntfs_ino;
883 base_ni = ctx->base_ntfs_ino;
884 ntfs_debug("Entering for inode 0x%lx, type 0x%x.", ni->mft_no, type);
885 if (!base_ni) {
886 /* First call happens with the base mft record. */
887 base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino;
888 ctx->base_mrec = ctx->mrec;
889 }
890 if (ni == base_ni)
891 ctx->base_attr = ctx->attr;
892 if (type == AT_END)
893 goto not_found;
894 vol = base_ni->vol;
895 al_start = base_ni->attr_list;
896 al_end = al_start + base_ni->attr_list_size;
897 if (!ctx->al_entry)
898 ctx->al_entry = (ATTR_LIST_ENTRY*)al_start;
899 /*
900 * Iterate over entries in attribute list starting at @ctx->al_entry,
901 * or the entry following that, if @ctx->is_first is 'true'.
902 */
903 if (ctx->is_first) {
904 al_entry = ctx->al_entry;
905 ctx->is_first = false;
906 } else
907 al_entry = (ATTR_LIST_ENTRY*)((u8*)ctx->al_entry +
908 le16_to_cpu(ctx->al_entry->length));
909 for (;; al_entry = next_al_entry) {
910 /* Out of bounds check. */
911 if ((u8*)al_entry < base_ni->attr_list ||
912 (u8*)al_entry > al_end)
913 break; /* Inode is corrupt. */
914 ctx->al_entry = al_entry;
915 /* Catch the end of the attribute list. */
916 if ((u8*)al_entry == al_end)
917 goto not_found;
918 if (!al_entry->length)
919 break;
920 if ((u8*)al_entry + 6 > al_end || (u8*)al_entry +
921 le16_to_cpu(al_entry->length) > al_end)
922 break;
923 next_al_entry = (ATTR_LIST_ENTRY*)((u8*)al_entry +
924 le16_to_cpu(al_entry->length));
925 if (le32_to_cpu(al_entry->type) > le32_to_cpu(type))
926 goto not_found;
927 if (type != al_entry->type)
928 continue;
929 /*
930 * If @name is present, compare the two names. If @name is
931 * missing, assume we want an unnamed attribute.
932 */
933 al_name_len = al_entry->name_length;
934 al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset);
935 if (!name) {
936 if (al_name_len)
937 goto not_found;
938 } else if (!ntfs_are_names_equal(al_name, al_name_len, name,
939 name_len, ic, vol->upcase, vol->upcase_len)) {
940 register int rc;
941
942 rc = ntfs_collate_names(name, name_len, al_name,
943 al_name_len, 1, IGNORE_CASE,
944 vol->upcase, vol->upcase_len);
945 /*
946 * If @name collates before al_name, there is no
947 * matching attribute.
948 */
949 if (rc == -1)
950 goto not_found;
951 /* If the strings are not equal, continue search. */
952 if (rc)
953 continue;
954 /*
955 * FIXME: Reverse engineering showed 0, IGNORE_CASE but
956 * that is inconsistent with ntfs_attr_find(). The
957 * subsequent rc checks were also different. Perhaps I
958 * made a mistake in one of the two. Need to recheck
959 * which is correct or at least see what is going on...
960 * (AIA)
961 */
962 rc = ntfs_collate_names(name, name_len, al_name,
963 al_name_len, 1, CASE_SENSITIVE,
964 vol->upcase, vol->upcase_len);
965 if (rc == -1)
966 goto not_found;
967 if (rc)
968 continue;
969 }
970 /*
971 * The names match or @name not present and attribute is
972 * unnamed. Now check @lowest_vcn. Continue search if the
973 * next attribute list entry still fits @lowest_vcn. Otherwise
974 * we have reached the right one or the search has failed.
975 */
976 if (lowest_vcn && (u8*)next_al_entry >= al_start &&
977 (u8*)next_al_entry + 6 < al_end &&
978 (u8*)next_al_entry + le16_to_cpu(
979 next_al_entry->length) <= al_end &&
980 sle64_to_cpu(next_al_entry->lowest_vcn) <=
981 lowest_vcn &&
982 next_al_entry->type == al_entry->type &&
983 next_al_entry->name_length == al_name_len &&
984 ntfs_are_names_equal((ntfschar*)((u8*)
985 next_al_entry +
986 next_al_entry->name_offset),
987 next_al_entry->name_length,
988 al_name, al_name_len, CASE_SENSITIVE,
989 vol->upcase, vol->upcase_len))
990 continue;
991 if (MREF_LE(al_entry->mft_reference) == ni->mft_no) {
992 if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) {
993 ntfs_error(vol->sb, "Found stale mft "
994 "reference in attribute list "
995 "of base inode 0x%lx.%s",
996 base_ni->mft_no, es);
997 err = -EIO;
998 break;
999 }
1000 } else { /* Mft references do not match. */
1001 /* If there is a mapped record unmap it first. */
1002 if (ni != base_ni)
1003 unmap_extent_mft_record(ni);
1004 /* Do we want the base record back? */
1005 if (MREF_LE(al_entry->mft_reference) ==
1006 base_ni->mft_no) {
1007 ni = ctx->ntfs_ino = base_ni;
1008 ctx->mrec = ctx->base_mrec;
1009 } else {
1010 /* We want an extent record. */
1011 ctx->mrec = map_extent_mft_record(base_ni,
1012 le64_to_cpu(
1013 al_entry->mft_reference), &ni);
1014 if (IS_ERR(ctx->mrec)) {
1015 ntfs_error(vol->sb, "Failed to map "
1016 "extent mft record "
1017 "0x%lx of base inode "
1018 "0x%lx.%s",
1019 MREF_LE(al_entry->
1020 mft_reference),
1021 base_ni->mft_no, es);
1022 err = PTR_ERR(ctx->mrec);
1023 if (err == -ENOENT)
1024 err = -EIO;
1025 /* Cause @ctx to be sanitized below. */
1026 ni = NULL;
1027 break;
1028 }
1029 ctx->ntfs_ino = ni;
1030 }
1031 ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
1032 le16_to_cpu(ctx->mrec->attrs_offset));
1033 }
1034 /*
1035 * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the
1036 * mft record containing the attribute represented by the
1037 * current al_entry.
1038 */
1039 /*
1040 * We could call into ntfs_attr_find() to find the right
1041 * attribute in this mft record but this would be less
1042 * efficient and not quite accurate as ntfs_attr_find() ignores
1043 * the attribute instance numbers for example which become
1044 * important when one plays with attribute lists. Also,
1045 * because a proper match has been found in the attribute list
1046 * entry above, the comparison can now be optimized. So it is
1047 * worth re-implementing a simplified ntfs_attr_find() here.
1048 */
1049 a = ctx->attr;
1050 /*
1051 * Use a manual loop so we can still use break and continue
1052 * with the same meanings as above.
1053 */
1054do_next_attr_loop:
1055 if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
1056 le32_to_cpu(ctx->mrec->bytes_allocated))
1057 break;
1058 if (a->type == AT_END)
1059 break;
1060 if (!a->length)
1061 break;
1062 if (al_entry->instance != a->instance)
1063 goto do_next_attr;
1064 /*
1065 * If the type and/or the name are mismatched between the
1066 * attribute list entry and the attribute record, there is
1067 * corruption so we break and return error EIO.
1068 */
1069 if (al_entry->type != a->type)
1070 break;
1071 if (!ntfs_are_names_equal((ntfschar*)((u8*)a +
1072 le16_to_cpu(a->name_offset)), a->name_length,
1073 al_name, al_name_len, CASE_SENSITIVE,
1074 vol->upcase, vol->upcase_len))
1075 break;
1076 ctx->attr = a;
1077 /*
1078 * If no @val specified or @val specified and it matches, we
1079 * have found it!
1080 */
1081 if (!val || (!a->non_resident && le32_to_cpu(
1082 a->data.resident.value_length) == val_len &&
1083 !memcmp((u8*)a +
1084 le16_to_cpu(a->data.resident.value_offset),
1085 val, val_len))) {
1086 ntfs_debug("Done, found.");
1087 return 0;
1088 }
1089do_next_attr:
1090 /* Proceed to the next attribute in the current mft record. */
1091 a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length));
1092 goto do_next_attr_loop;
1093 }
1094 if (!err) {
1095 ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt "
1096 "attribute list attribute.%s", base_ni->mft_no,
1097 es);
1098 err = -EIO;
1099 }
1100 if (ni != base_ni) {
1101 if (ni)
1102 unmap_extent_mft_record(ni);
1103 ctx->ntfs_ino = base_ni;
1104 ctx->mrec = ctx->base_mrec;
1105 ctx->attr = ctx->base_attr;
1106 }
1107 if (err != -ENOMEM)
1108 NVolSetErrors(vol);
1109 return err;
1110not_found:
1111 /*
1112 * If we were looking for AT_END, we reset the search context @ctx and
1113 * use ntfs_attr_find() to seek to the end of the base mft record.
1114 */
1115 if (type == AT_END) {
1116 ntfs_attr_reinit_search_ctx(ctx);
1117 return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len,
1118 ctx);
1119 }
1120 /*
1121 * The attribute was not found. Before we return, we want to ensure
1122 * @ctx->mrec and @ctx->attr indicate the position at which the
1123 * attribute should be inserted in the base mft record. Since we also
1124 * want to preserve @ctx->al_entry we cannot reinitialize the search
1125 * context using ntfs_attr_reinit_search_ctx() as this would set
1126 * @ctx->al_entry to NULL. Thus we do the necessary bits manually (see
1127 * ntfs_attr_init_search_ctx() below). Note, we _only_ preserve
1128 * @ctx->al_entry as the remaining fields (base_*) are identical to
1129 * their non base_ counterparts and we cannot set @ctx->base_attr
1130 * correctly yet as we do not know what @ctx->attr will be set to by
1131 * the call to ntfs_attr_find() below.
1132 */
1133 if (ni != base_ni)
1134 unmap_extent_mft_record(ni);
1135 ctx->mrec = ctx->base_mrec;
1136 ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
1137 le16_to_cpu(ctx->mrec->attrs_offset));
1138 ctx->is_first = true;
1139 ctx->ntfs_ino = base_ni;
1140 ctx->base_ntfs_ino = NULL;
1141 ctx->base_mrec = NULL;
1142 ctx->base_attr = NULL;
1143 /*
1144 * In case there are multiple matches in the base mft record, need to
1145 * keep enumerating until we get an attribute not found response (or
1146 * another error), otherwise we would keep returning the same attribute
1147 * over and over again and all programs using us for enumeration would
1148 * lock up in a tight loop.
1149 */
1150 do {
1151 err = ntfs_attr_find(type, name, name_len, ic, val, val_len,
1152 ctx);
1153 } while (!err);
1154 ntfs_debug("Done, not found.");
1155 return err;
1156}
1157
1158/**
1159 * ntfs_attr_lookup - find an attribute in an ntfs inode
1160 * @type: attribute type to find
1161 * @name: attribute name to find (optional, i.e. NULL means don't care)
1162 * @name_len: attribute name length (only needed if @name present)
1163 * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
1164 * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
1165 * @val: attribute value to find (optional, resident attributes only)
1166 * @val_len: attribute value length
1167 * @ctx: search context with mft record and attribute to search from
1168 *
1169 * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must
1170 * be the base mft record and @ctx must have been obtained from a call to
1171 * ntfs_attr_get_search_ctx().
1172 *
1173 * This function transparently handles attribute lists and @ctx is used to
1174 * continue searches where they were left off at.
1175 *
1176 * After finishing with the attribute/mft record you need to call
1177 * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
1178 * mapped inodes, etc).
1179 *
1180 * Return 0 if the search was successful and -errno if not.
1181 *
1182 * When 0, @ctx->attr is the found attribute and it is in mft record
1183 * @ctx->mrec. If an attribute list attribute is present, @ctx->al_entry is
1184 * the attribute list entry of the found attribute.
1185 *
1186 * When -ENOENT, @ctx->attr is the attribute which collates just after the
1187 * attribute being searched for, i.e. if one wants to add the attribute to the
1188 * mft record this is the correct place to insert it into. If an attribute
1189 * list attribute is present, @ctx->al_entry is the attribute list entry which
1190 * collates just after the attribute list entry of the attribute being searched
1191 * for, i.e. if one wants to add the attribute to the mft record this is the
1192 * correct place to insert its attribute list entry into.
1193 *
1194 * When -errno != -ENOENT, an error occurred during the lookup. @ctx->attr is
1195 * then undefined and in particular you should not rely on it not changing.
1196 */
1197int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
1198 const u32 name_len, const IGNORE_CASE_BOOL ic,
1199 const VCN lowest_vcn, const u8 *val, const u32 val_len,
1200 ntfs_attr_search_ctx *ctx)
1201{
1202 ntfs_inode *base_ni;
1203
1204 ntfs_debug("Entering.");
1205 BUG_ON(IS_ERR(ctx->mrec));
1206 if (ctx->base_ntfs_ino)
1207 base_ni = ctx->base_ntfs_ino;
1208 else
1209 base_ni = ctx->ntfs_ino;
1210 /* Sanity check, just for debugging really. */
1211 BUG_ON(!base_ni);
1212 if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST)
1213 return ntfs_attr_find(type, name, name_len, ic, val, val_len,
1214 ctx);
1215 return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn,
1216 val, val_len, ctx);
1217}
1218
1219/**
1220 * ntfs_attr_init_search_ctx - initialize an attribute search context
1221 * @ctx: attribute search context to initialize
1222 * @ni: ntfs inode with which to initialize the search context
1223 * @mrec: mft record with which to initialize the search context
1224 *
1225 * Initialize the attribute search context @ctx with @ni and @mrec.
1226 */
1227static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx,
1228 ntfs_inode *ni, MFT_RECORD *mrec)
1229{
1230 *ctx = (ntfs_attr_search_ctx) {
1231 .mrec = mrec,
1232 /* Sanity checks are performed elsewhere. */
1233 .attr = (ATTR_RECORD*)((u8*)mrec +
1234 le16_to_cpu(mrec->attrs_offset)),
1235 .is_first = true,
1236 .ntfs_ino = ni,
1237 };
1238}
1239
1240/**
1241 * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
1242 * @ctx: attribute search context to reinitialize
1243 *
1244 * Reinitialize the attribute search context @ctx, unmapping an associated
1245 * extent mft record if present, and initialize the search context again.
1246 *
1247 * This is used when a search for a new attribute is being started to reset
1248 * the search context to the beginning.
1249 */
1250void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx)
1251{
1252 if (likely(!ctx->base_ntfs_ino)) {
1253 /* No attribute list. */
1254 ctx->is_first = true;
1255 /* Sanity checks are performed elsewhere. */
1256 ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
1257 le16_to_cpu(ctx->mrec->attrs_offset));
1258 /*
1259 * This needs resetting due to ntfs_external_attr_find() which
1260 * can leave it set despite having zeroed ctx->base_ntfs_ino.
1261 */
1262 ctx->al_entry = NULL;
1263 return;
1264 } /* Attribute list. */
1265 if (ctx->ntfs_ino != ctx->base_ntfs_ino)
1266 unmap_extent_mft_record(ctx->ntfs_ino);
1267 ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
1268 return;
1269}
1270
1271/**
1272 * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
1273 * @ni: ntfs inode with which to initialize the search context
1274 * @mrec: mft record with which to initialize the search context
1275 *
1276 * Allocate a new attribute search context, initialize it with @ni and @mrec,
1277 * and return it. Return NULL if allocation failed.
1278 */
1279ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec)
1280{
1281 ntfs_attr_search_ctx *ctx;
1282
1283 ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, GFP_NOFS);
1284 if (ctx)
1285 ntfs_attr_init_search_ctx(ctx, ni, mrec);
1286 return ctx;
1287}
1288
1289/**
1290 * ntfs_attr_put_search_ctx - release an attribute search context
1291 * @ctx: attribute search context to free
1292 *
1293 * Release the attribute search context @ctx, unmapping an associated extent
1294 * mft record if present.
1295 */
1296void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx)
1297{
1298 if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino)
1299 unmap_extent_mft_record(ctx->ntfs_ino);
1300 kmem_cache_free(ntfs_attr_ctx_cache, ctx);
1301 return;
1302}
1303
1304#ifdef NTFS_RW
1305
1306/**
1307 * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
1308 * @vol: ntfs volume to which the attribute belongs
1309 * @type: attribute type which to find
1310 *
1311 * Search for the attribute definition record corresponding to the attribute
1312 * @type in the $AttrDef system file.
1313 *
1314 * Return the attribute type definition record if found and NULL if not found.
1315 */
1316static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol,
1317 const ATTR_TYPE type)
1318{
1319 ATTR_DEF *ad;
1320
1321 BUG_ON(!vol->attrdef);
1322 BUG_ON(!type);
1323 for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef <
1324 vol->attrdef_size && ad->type; ++ad) {
1325 /* We have not found it yet, carry on searching. */
1326 if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
1327 continue;
1328 /* We found the attribute; return it. */
1329 if (likely(ad->type == type))
1330 return ad;
1331 /* We have gone too far already. No point in continuing. */
1332 break;
1333 }
1334 /* Attribute not found. */
1335 ntfs_debug("Attribute type 0x%x not found in $AttrDef.",
1336 le32_to_cpu(type));
1337 return NULL;
1338}
1339
1340/**
1341 * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
1342 * @vol: ntfs volume to which the attribute belongs
1343 * @type: attribute type which to check
1344 * @size: size which to check
1345 *
1346 * Check whether the @size in bytes is valid for an attribute of @type on the
1347 * ntfs volume @vol. This information is obtained from $AttrDef system file.
1348 *
1349 * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not
1350 * listed in $AttrDef.
1351 */
1352int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type,
1353 const s64 size)
1354{
1355 ATTR_DEF *ad;
1356
1357 BUG_ON(size < 0);
1358 /*
1359 * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not
1360 * listed in $AttrDef.
1361 */
1362 if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024))
1363 return -ERANGE;
1364 /* Get the $AttrDef entry for the attribute @type. */
1365 ad = ntfs_attr_find_in_attrdef(vol, type);
1366 if (unlikely(!ad))
1367 return -ENOENT;
1368 /* Do the bounds check. */
1369 if (((sle64_to_cpu(ad->min_size) > 0) &&
1370 size < sle64_to_cpu(ad->min_size)) ||
1371 ((sle64_to_cpu(ad->max_size) > 0) && size >
1372 sle64_to_cpu(ad->max_size)))
1373 return -ERANGE;
1374 return 0;
1375}
1376
1377/**
1378 * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
1379 * @vol: ntfs volume to which the attribute belongs
1380 * @type: attribute type which to check
1381 *
1382 * Check whether the attribute of @type on the ntfs volume @vol is allowed to
1383 * be non-resident. This information is obtained from $AttrDef system file.
1384 *
1385 * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, and
1386 * -ENOENT if the attribute is not listed in $AttrDef.
1387 */
1388int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type)
1389{
1390 ATTR_DEF *ad;
1391
1392 /* Find the attribute definition record in $AttrDef. */
1393 ad = ntfs_attr_find_in_attrdef(vol, type);
1394 if (unlikely(!ad))
1395 return -ENOENT;
1396 /* Check the flags and return the result. */
1397 if (ad->flags & ATTR_DEF_RESIDENT)
1398 return -EPERM;
1399 return 0;
1400}
1401
1402/**
1403 * ntfs_attr_can_be_resident - check if an attribute can be resident
1404 * @vol: ntfs volume to which the attribute belongs
1405 * @type: attribute type which to check
1406 *
1407 * Check whether the attribute of @type on the ntfs volume @vol is allowed to
1408 * be resident. This information is derived from our ntfs knowledge and may
1409 * not be completely accurate, especially when user defined attributes are
1410 * present. Basically we allow everything to be resident except for index
1411 * allocation and $EA attributes.
1412 *
1413 * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
1414 *
1415 * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
1416 * otherwise windows will not boot (blue screen of death)! We cannot
1417 * check for this here as we do not know which inode's $Bitmap is
1418 * being asked about so the caller needs to special case this.
1419 */
1420int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type)
1421{
1422 if (type == AT_INDEX_ALLOCATION)
1423 return -EPERM;
1424 return 0;
1425}
1426
1427/**
1428 * ntfs_attr_record_resize - resize an attribute record
1429 * @m: mft record containing attribute record
1430 * @a: attribute record to resize
1431 * @new_size: new size in bytes to which to resize the attribute record @a
1432 *
1433 * Resize the attribute record @a, i.e. the resident part of the attribute, in
1434 * the mft record @m to @new_size bytes.
1435 *
1436 * Return 0 on success and -errno on error. The following error codes are
1437 * defined:
1438 * -ENOSPC - Not enough space in the mft record @m to perform the resize.
1439 *
1440 * Note: On error, no modifications have been performed whatsoever.
1441 *
1442 * Warning: If you make a record smaller without having copied all the data you
1443 * are interested in the data may be overwritten.
1444 */
1445int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
1446{
1447 ntfs_debug("Entering for new_size %u.", new_size);
1448 /* Align to 8 bytes if it is not already done. */
1449 if (new_size & 7)
1450 new_size = (new_size + 7) & ~7;
1451 /* If the actual attribute length has changed, move things around. */
1452 if (new_size != le32_to_cpu(a->length)) {
1453 u32 new_muse = le32_to_cpu(m->bytes_in_use) -
1454 le32_to_cpu(a->length) + new_size;
1455 /* Not enough space in this mft record. */
1456 if (new_muse > le32_to_cpu(m->bytes_allocated))
1457 return -ENOSPC;
1458 /* Move attributes following @a to their new location. */
1459 memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length),
1460 le32_to_cpu(m->bytes_in_use) - ((u8*)a -
1461 (u8*)m) - le32_to_cpu(a->length));
1462 /* Adjust @m to reflect the change in used space. */
1463 m->bytes_in_use = cpu_to_le32(new_muse);
1464 /* Adjust @a to reflect the new size. */
1465 if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length))
1466 a->length = cpu_to_le32(new_size);
1467 }
1468 return 0;
1469}
1470
1471/**
1472 * ntfs_resident_attr_value_resize - resize the value of a resident attribute
1473 * @m: mft record containing attribute record
1474 * @a: attribute record whose value to resize
1475 * @new_size: new size in bytes to which to resize the attribute value of @a
1476 *
1477 * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
1478 * If the value is made bigger, the newly allocated space is cleared.
1479 *
1480 * Return 0 on success and -errno on error. The following error codes are
1481 * defined:
1482 * -ENOSPC - Not enough space in the mft record @m to perform the resize.
1483 *
1484 * Note: On error, no modifications have been performed whatsoever.
1485 *
1486 * Warning: If you make a record smaller without having copied all the data you
1487 * are interested in the data may be overwritten.
1488 */
1489int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
1490 const u32 new_size)
1491{
1492 u32 old_size;
1493
1494 /* Resize the resident part of the attribute record. */
1495 if (ntfs_attr_record_resize(m, a,
1496 le16_to_cpu(a->data.resident.value_offset) + new_size))
1497 return -ENOSPC;
1498 /*
1499 * The resize succeeded! If we made the attribute value bigger, clear
1500 * the area between the old size and @new_size.
1501 */
1502 old_size = le32_to_cpu(a->data.resident.value_length);
1503 if (new_size > old_size)
1504 memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
1505 old_size, 0, new_size - old_size);
1506 /* Finally update the length of the attribute value. */
1507 a->data.resident.value_length = cpu_to_le32(new_size);
1508 return 0;
1509}
1510
1511/**
1512 * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
1513 * @ni: ntfs inode describing the attribute to convert
1514 * @data_size: size of the resident data to copy to the non-resident attribute
1515 *
1516 * Convert the resident ntfs attribute described by the ntfs inode @ni to a
1517 * non-resident one.
1518 *
1519 * @data_size must be equal to the attribute value size. This is needed since
1520 * we need to know the size before we can map the mft record and our callers
1521 * always know it. The reason we cannot simply read the size from the vfs
1522 * inode i_size is that this is not necessarily uptodate. This happens when
1523 * ntfs_attr_make_non_resident() is called in the ->truncate call path(s).
1524 *
1525 * Return 0 on success and -errno on error. The following error return codes
1526 * are defined:
1527 * -EPERM - The attribute is not allowed to be non-resident.
1528 * -ENOMEM - Not enough memory.
1529 * -ENOSPC - Not enough disk space.
1530 * -EINVAL - Attribute not defined on the volume.
1531 * -EIO - I/o error or other error.
1532 * Note that -ENOSPC is also returned in the case that there is not enough
1533 * space in the mft record to do the conversion. This can happen when the mft
1534 * record is already very full. The caller is responsible for trying to make
1535 * space in the mft record and trying again. FIXME: Do we need a separate
1536 * error return code for this kind of -ENOSPC or is it always worth trying
1537 * again in case the attribute may then fit in a resident state so no need to
1538 * make it non-resident at all? Ho-hum... (AIA)
1539 *
1540 * NOTE to self: No changes in the attribute list are required to move from
1541 * a resident to a non-resident attribute.
1542 *
1543 * Locking: - The caller must hold i_mutex on the inode.
1544 */
1545int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
1546{
1547 s64 new_size;
1548 struct inode *vi = VFS_I(ni);
1549 ntfs_volume *vol = ni->vol;
1550 ntfs_inode *base_ni;
1551 MFT_RECORD *m;
1552 ATTR_RECORD *a;
1553 ntfs_attr_search_ctx *ctx;
1554 struct page *page;
1555 runlist_element *rl;
1556 u8 *kaddr;
1557 unsigned long flags;
1558 int mp_size, mp_ofs, name_ofs, arec_size, err, err2;
1559 u32 attr_size;
1560 u8 old_res_attr_flags;
1561
1562 /* Check that the attribute is allowed to be non-resident. */
1563 err = ntfs_attr_can_be_non_resident(vol, ni->type);
1564 if (unlikely(err)) {
1565 if (err == -EPERM)
1566 ntfs_debug("Attribute is not allowed to be "
1567 "non-resident.");
1568 else
1569 ntfs_debug("Attribute not defined on the NTFS "
1570 "volume!");
1571 return err;
1572 }
1573 /*
1574 * FIXME: Compressed and encrypted attributes are not supported when
1575 * writing and we should never have gotten here for them.
1576 */
1577 BUG_ON(NInoCompressed(ni));
1578 BUG_ON(NInoEncrypted(ni));
1579 /*
1580 * The size needs to be aligned to a cluster boundary for allocation
1581 * purposes.
1582 */
1583 new_size = (data_size + vol->cluster_size - 1) &
1584 ~(vol->cluster_size - 1);
1585 if (new_size > 0) {
1586 /*
1587 * Will need the page later and since the page lock nests
1588 * outside all ntfs locks, we need to get the page now.
1589 */
1590 page = find_or_create_page(vi->i_mapping, 0,
1591 mapping_gfp_mask(vi->i_mapping));
1592 if (unlikely(!page))
1593 return -ENOMEM;
1594 /* Start by allocating clusters to hold the attribute value. */
1595 rl = ntfs_cluster_alloc(vol, 0, new_size >>
1596 vol->cluster_size_bits, -1, DATA_ZONE, true);
1597 if (IS_ERR(rl)) {
1598 err = PTR_ERR(rl);
1599 ntfs_debug("Failed to allocate cluster%s, error code "
1600 "%i.", (new_size >>
1601 vol->cluster_size_bits) > 1 ? "s" : "",
1602 err);
1603 goto page_err_out;
1604 }
1605 } else {
1606 rl = NULL;
1607 page = NULL;
1608 }
1609 /* Determine the size of the mapping pairs array. */
1610 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1);
1611 if (unlikely(mp_size < 0)) {
1612 err = mp_size;
1613 ntfs_debug("Failed to get size for mapping pairs array, error "
1614 "code %i.", err);
1615 goto rl_err_out;
1616 }
1617 down_write(&ni->runlist.lock);
1618 if (!NInoAttr(ni))
1619 base_ni = ni;
1620 else
1621 base_ni = ni->ext.base_ntfs_ino;
1622 m = map_mft_record(base_ni);
1623 if (IS_ERR(m)) {
1624 err = PTR_ERR(m);
1625 m = NULL;
1626 ctx = NULL;
1627 goto err_out;
1628 }
1629 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1630 if (unlikely(!ctx)) {
1631 err = -ENOMEM;
1632 goto err_out;
1633 }
1634 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1635 CASE_SENSITIVE, 0, NULL, 0, ctx);
1636 if (unlikely(err)) {
1637 if (err == -ENOENT)
1638 err = -EIO;
1639 goto err_out;
1640 }
1641 m = ctx->mrec;
1642 a = ctx->attr;
1643 BUG_ON(NInoNonResident(ni));
1644 BUG_ON(a->non_resident);
1645 /*
1646 * Calculate new offsets for the name and the mapping pairs array.
1647 */
1648 if (NInoSparse(ni) || NInoCompressed(ni))
1649 name_ofs = (offsetof(ATTR_REC,
1650 data.non_resident.compressed_size) +
1651 sizeof(a->data.non_resident.compressed_size) +
1652 7) & ~7;
1653 else
1654 name_ofs = (offsetof(ATTR_REC,
1655 data.non_resident.compressed_size) + 7) & ~7;
1656 mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
1657 /*
1658 * Determine the size of the resident part of the now non-resident
1659 * attribute record.
1660 */
1661 arec_size = (mp_ofs + mp_size + 7) & ~7;
1662 /*
1663 * If the page is not uptodate bring it uptodate by copying from the
1664 * attribute value.
1665 */
1666 attr_size = le32_to_cpu(a->data.resident.value_length);
1667 BUG_ON(attr_size != data_size);
1668 if (page && !PageUptodate(page)) {
1669 kaddr = kmap_atomic(page);
1670 memcpy(kaddr, (u8*)a +
1671 le16_to_cpu(a->data.resident.value_offset),
1672 attr_size);
1673 memset(kaddr + attr_size, 0, PAGE_SIZE - attr_size);
1674 kunmap_atomic(kaddr);
1675 flush_dcache_page(page);
1676 SetPageUptodate(page);
1677 }
1678 /* Backup the attribute flag. */
1679 old_res_attr_flags = a->data.resident.flags;
1680 /* Resize the resident part of the attribute record. */
1681 err = ntfs_attr_record_resize(m, a, arec_size);
1682 if (unlikely(err))
1683 goto err_out;
1684 /*
1685 * Convert the resident part of the attribute record to describe a
1686 * non-resident attribute.
1687 */
1688 a->non_resident = 1;
1689 /* Move the attribute name if it exists and update the offset. */
1690 if (a->name_length)
1691 memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
1692 a->name_length * sizeof(ntfschar));
1693 a->name_offset = cpu_to_le16(name_ofs);
1694 /* Setup the fields specific to non-resident attributes. */
1695 a->data.non_resident.lowest_vcn = 0;
1696 a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
1697 vol->cluster_size_bits);
1698 a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
1699 memset(&a->data.non_resident.reserved, 0,
1700 sizeof(a->data.non_resident.reserved));
1701 a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
1702 a->data.non_resident.data_size =
1703 a->data.non_resident.initialized_size =
1704 cpu_to_sle64(attr_size);
1705 if (NInoSparse(ni) || NInoCompressed(ni)) {
1706 a->data.non_resident.compression_unit = 0;
1707 if (NInoCompressed(ni) || vol->major_ver < 3)
1708 a->data.non_resident.compression_unit = 4;
1709 a->data.non_resident.compressed_size =
1710 a->data.non_resident.allocated_size;
1711 } else
1712 a->data.non_resident.compression_unit = 0;
1713 /* Generate the mapping pairs array into the attribute record. */
1714 err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
1715 arec_size - mp_ofs, rl, 0, -1, NULL);
1716 if (unlikely(err)) {
1717 ntfs_debug("Failed to build mapping pairs, error code %i.",
1718 err);
1719 goto undo_err_out;
1720 }
1721 /* Setup the in-memory attribute structure to be non-resident. */
1722 ni->runlist.rl = rl;
1723 write_lock_irqsave(&ni->size_lock, flags);
1724 ni->allocated_size = new_size;
1725 if (NInoSparse(ni) || NInoCompressed(ni)) {
1726 ni->itype.compressed.size = ni->allocated_size;
1727 if (a->data.non_resident.compression_unit) {
1728 ni->itype.compressed.block_size = 1U << (a->data.
1729 non_resident.compression_unit +
1730 vol->cluster_size_bits);
1731 ni->itype.compressed.block_size_bits =
1732 ffs(ni->itype.compressed.block_size) -
1733 1;
1734 ni->itype.compressed.block_clusters = 1U <<
1735 a->data.non_resident.compression_unit;
1736 } else {
1737 ni->itype.compressed.block_size = 0;
1738 ni->itype.compressed.block_size_bits = 0;
1739 ni->itype.compressed.block_clusters = 0;
1740 }
1741 vi->i_blocks = ni->itype.compressed.size >> 9;
1742 } else
1743 vi->i_blocks = ni->allocated_size >> 9;
1744 write_unlock_irqrestore(&ni->size_lock, flags);
1745 /*
1746 * This needs to be last since the address space operations ->read_folio
1747 * and ->writepage can run concurrently with us as they are not
1748 * serialized on i_mutex. Note, we are not allowed to fail once we flip
1749 * this switch, which is another reason to do this last.
1750 */
1751 NInoSetNonResident(ni);
1752 /* Mark the mft record dirty, so it gets written back. */
1753 flush_dcache_mft_record_page(ctx->ntfs_ino);
1754 mark_mft_record_dirty(ctx->ntfs_ino);
1755 ntfs_attr_put_search_ctx(ctx);
1756 unmap_mft_record(base_ni);
1757 up_write(&ni->runlist.lock);
1758 if (page) {
1759 set_page_dirty(page);
1760 unlock_page(page);
1761 put_page(page);
1762 }
1763 ntfs_debug("Done.");
1764 return 0;
1765undo_err_out:
1766 /* Convert the attribute back into a resident attribute. */
1767 a->non_resident = 0;
1768 /* Move the attribute name if it exists and update the offset. */
1769 name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) +
1770 sizeof(a->data.resident.reserved) + 7) & ~7;
1771 if (a->name_length)
1772 memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
1773 a->name_length * sizeof(ntfschar));
1774 mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
1775 a->name_offset = cpu_to_le16(name_ofs);
1776 arec_size = (mp_ofs + attr_size + 7) & ~7;
1777 /* Resize the resident part of the attribute record. */
1778 err2 = ntfs_attr_record_resize(m, a, arec_size);
1779 if (unlikely(err2)) {
1780 /*
1781 * This cannot happen (well if memory corruption is at work it
1782 * could happen in theory), but deal with it as well as we can.
1783 * If the old size is too small, truncate the attribute,
1784 * otherwise simply give it a larger allocated size.
1785 * FIXME: Should check whether chkdsk complains when the
1786 * allocated size is much bigger than the resident value size.
1787 */
1788 arec_size = le32_to_cpu(a->length);
1789 if ((mp_ofs + attr_size) > arec_size) {
1790 err2 = attr_size;
1791 attr_size = arec_size - mp_ofs;
1792 ntfs_error(vol->sb, "Failed to undo partial resident "
1793 "to non-resident attribute "
1794 "conversion. Truncating inode 0x%lx, "
1795 "attribute type 0x%x from %i bytes to "
1796 "%i bytes to maintain metadata "
1797 "consistency. THIS MEANS YOU ARE "
1798 "LOSING %i BYTES DATA FROM THIS %s.",
1799 vi->i_ino,
1800 (unsigned)le32_to_cpu(ni->type),
1801 err2, attr_size, err2 - attr_size,
1802 ((ni->type == AT_DATA) &&
1803 !ni->name_len) ? "FILE": "ATTRIBUTE");
1804 write_lock_irqsave(&ni->size_lock, flags);
1805 ni->initialized_size = attr_size;
1806 i_size_write(vi, attr_size);
1807 write_unlock_irqrestore(&ni->size_lock, flags);
1808 }
1809 }
1810 /* Setup the fields specific to resident attributes. */
1811 a->data.resident.value_length = cpu_to_le32(attr_size);
1812 a->data.resident.value_offset = cpu_to_le16(mp_ofs);
1813 a->data.resident.flags = old_res_attr_flags;
1814 memset(&a->data.resident.reserved, 0,
1815 sizeof(a->data.resident.reserved));
1816 /* Copy the data from the page back to the attribute value. */
1817 if (page) {
1818 kaddr = kmap_atomic(page);
1819 memcpy((u8*)a + mp_ofs, kaddr, attr_size);
1820 kunmap_atomic(kaddr);
1821 }
1822 /* Setup the allocated size in the ntfs inode in case it changed. */
1823 write_lock_irqsave(&ni->size_lock, flags);
1824 ni->allocated_size = arec_size - mp_ofs;
1825 write_unlock_irqrestore(&ni->size_lock, flags);
1826 /* Mark the mft record dirty, so it gets written back. */
1827 flush_dcache_mft_record_page(ctx->ntfs_ino);
1828 mark_mft_record_dirty(ctx->ntfs_ino);
1829err_out:
1830 if (ctx)
1831 ntfs_attr_put_search_ctx(ctx);
1832 if (m)
1833 unmap_mft_record(base_ni);
1834 ni->runlist.rl = NULL;
1835 up_write(&ni->runlist.lock);
1836rl_err_out:
1837 if (rl) {
1838 if (ntfs_cluster_free_from_rl(vol, rl) < 0) {
1839 ntfs_error(vol->sb, "Failed to release allocated "
1840 "cluster(s) in error code path. Run "
1841 "chkdsk to recover the lost "
1842 "cluster(s).");
1843 NVolSetErrors(vol);
1844 }
1845 ntfs_free(rl);
1846page_err_out:
1847 unlock_page(page);
1848 put_page(page);
1849 }
1850 if (err == -EINVAL)
1851 err = -EIO;
1852 return err;
1853}
1854
1855/**
1856 * ntfs_attr_extend_allocation - extend the allocated space of an attribute
1857 * @ni: ntfs inode of the attribute whose allocation to extend
1858 * @new_alloc_size: new size in bytes to which to extend the allocation to
1859 * @new_data_size: new size in bytes to which to extend the data to
1860 * @data_start: beginning of region which is required to be non-sparse
1861 *
1862 * Extend the allocated space of an attribute described by the ntfs inode @ni
1863 * to @new_alloc_size bytes. If @data_start is -1, the whole extension may be
1864 * implemented as a hole in the file (as long as both the volume and the ntfs
1865 * inode @ni have sparse support enabled). If @data_start is >= 0, then the
1866 * region between the old allocated size and @data_start - 1 may be made sparse
1867 * but the regions between @data_start and @new_alloc_size must be backed by
1868 * actual clusters.
1869 *
1870 * If @new_data_size is -1, it is ignored. If it is >= 0, then the data size
1871 * of the attribute is extended to @new_data_size. Note that the i_size of the
1872 * vfs inode is not updated. Only the data size in the base attribute record
1873 * is updated. The caller has to update i_size separately if this is required.
1874 * WARNING: It is a BUG() for @new_data_size to be smaller than the old data
1875 * size as well as for @new_data_size to be greater than @new_alloc_size.
1876 *
1877 * For resident attributes this involves resizing the attribute record and if
1878 * necessary moving it and/or other attributes into extent mft records and/or
1879 * converting the attribute to a non-resident attribute which in turn involves
1880 * extending the allocation of a non-resident attribute as described below.
1881 *
1882 * For non-resident attributes this involves allocating clusters in the data
1883 * zone on the volume (except for regions that are being made sparse) and
1884 * extending the run list to describe the allocated clusters as well as
1885 * updating the mapping pairs array of the attribute. This in turn involves
1886 * resizing the attribute record and if necessary moving it and/or other
1887 * attributes into extent mft records and/or splitting the attribute record
1888 * into multiple extent attribute records.
1889 *
1890 * Also, the attribute list attribute is updated if present and in some of the
1891 * above cases (the ones where extent mft records/attributes come into play),
1892 * an attribute list attribute is created if not already present.
1893 *
1894 * Return the new allocated size on success and -errno on error. In the case
1895 * that an error is encountered but a partial extension at least up to
1896 * @data_start (if present) is possible, the allocation is partially extended
1897 * and this is returned. This means the caller must check the returned size to
1898 * determine if the extension was partial. If @data_start is -1 then partial
1899 * allocations are not performed.
1900 *
1901 * WARNING: Do not call ntfs_attr_extend_allocation() for $MFT/$DATA.
1902 *
1903 * Locking: This function takes the runlist lock of @ni for writing as well as
1904 * locking the mft record of the base ntfs inode. These locks are maintained
1905 * throughout execution of the function. These locks are required so that the
1906 * attribute can be resized safely and so that it can for example be converted
1907 * from resident to non-resident safely.
1908 *
1909 * TODO: At present attribute list attribute handling is not implemented.
1910 *
1911 * TODO: At present it is not safe to call this function for anything other
1912 * than the $DATA attribute(s) of an uncompressed and unencrypted file.
1913 */
1914s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
1915 const s64 new_data_size, const s64 data_start)
1916{
1917 VCN vcn;
1918 s64 ll, allocated_size, start = data_start;
1919 struct inode *vi = VFS_I(ni);
1920 ntfs_volume *vol = ni->vol;
1921 ntfs_inode *base_ni;
1922 MFT_RECORD *m;
1923 ATTR_RECORD *a;
1924 ntfs_attr_search_ctx *ctx;
1925 runlist_element *rl, *rl2;
1926 unsigned long flags;
1927 int err, mp_size;
1928 u32 attr_len = 0; /* Silence stupid gcc warning. */
1929 bool mp_rebuilt;
1930
1931#ifdef DEBUG
1932 read_lock_irqsave(&ni->size_lock, flags);
1933 allocated_size = ni->allocated_size;
1934 read_unlock_irqrestore(&ni->size_lock, flags);
1935 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
1936 "old_allocated_size 0x%llx, "
1937 "new_allocated_size 0x%llx, new_data_size 0x%llx, "
1938 "data_start 0x%llx.", vi->i_ino,
1939 (unsigned)le32_to_cpu(ni->type),
1940 (unsigned long long)allocated_size,
1941 (unsigned long long)new_alloc_size,
1942 (unsigned long long)new_data_size,
1943 (unsigned long long)start);
1944#endif
1945retry_extend:
1946 /*
1947 * For non-resident attributes, @start and @new_size need to be aligned
1948 * to cluster boundaries for allocation purposes.
1949 */
1950 if (NInoNonResident(ni)) {
1951 if (start > 0)
1952 start &= ~(s64)vol->cluster_size_mask;
1953 new_alloc_size = (new_alloc_size + vol->cluster_size - 1) &
1954 ~(s64)vol->cluster_size_mask;
1955 }
1956 BUG_ON(new_data_size >= 0 && new_data_size > new_alloc_size);
1957 /* Check if new size is allowed in $AttrDef. */
1958 err = ntfs_attr_size_bounds_check(vol, ni->type, new_alloc_size);
1959 if (unlikely(err)) {
1960 /* Only emit errors when the write will fail completely. */
1961 read_lock_irqsave(&ni->size_lock, flags);
1962 allocated_size = ni->allocated_size;
1963 read_unlock_irqrestore(&ni->size_lock, flags);
1964 if (start < 0 || start >= allocated_size) {
1965 if (err == -ERANGE) {
1966 ntfs_error(vol->sb, "Cannot extend allocation "
1967 "of inode 0x%lx, attribute "
1968 "type 0x%x, because the new "
1969 "allocation would exceed the "
1970 "maximum allowed size for "
1971 "this attribute type.",
1972 vi->i_ino, (unsigned)
1973 le32_to_cpu(ni->type));
1974 } else {
1975 ntfs_error(vol->sb, "Cannot extend allocation "
1976 "of inode 0x%lx, attribute "
1977 "type 0x%x, because this "
1978 "attribute type is not "
1979 "defined on the NTFS volume. "
1980 "Possible corruption! You "
1981 "should run chkdsk!",
1982 vi->i_ino, (unsigned)
1983 le32_to_cpu(ni->type));
1984 }
1985 }
1986 /* Translate error code to be POSIX conformant for write(2). */
1987 if (err == -ERANGE)
1988 err = -EFBIG;
1989 else
1990 err = -EIO;
1991 return err;
1992 }
1993 if (!NInoAttr(ni))
1994 base_ni = ni;
1995 else
1996 base_ni = ni->ext.base_ntfs_ino;
1997 /*
1998 * We will be modifying both the runlist (if non-resident) and the mft
1999 * record so lock them both down.
2000 */
2001 down_write(&ni->runlist.lock);
2002 m = map_mft_record(base_ni);
2003 if (IS_ERR(m)) {
2004 err = PTR_ERR(m);
2005 m = NULL;
2006 ctx = NULL;
2007 goto err_out;
2008 }
2009 ctx = ntfs_attr_get_search_ctx(base_ni, m);
2010 if (unlikely(!ctx)) {
2011 err = -ENOMEM;
2012 goto err_out;
2013 }
2014 read_lock_irqsave(&ni->size_lock, flags);
2015 allocated_size = ni->allocated_size;
2016 read_unlock_irqrestore(&ni->size_lock, flags);
2017 /*
2018 * If non-resident, seek to the last extent. If resident, there is
2019 * only one extent, so seek to that.
2020 */
2021 vcn = NInoNonResident(ni) ? allocated_size >> vol->cluster_size_bits :
2022 0;
2023 /*
2024 * Abort if someone did the work whilst we waited for the locks. If we
2025 * just converted the attribute from resident to non-resident it is
2026 * likely that exactly this has happened already. We cannot quite
2027 * abort if we need to update the data size.
2028 */
2029 if (unlikely(new_alloc_size <= allocated_size)) {
2030 ntfs_debug("Allocated size already exceeds requested size.");
2031 new_alloc_size = allocated_size;
2032 if (new_data_size < 0)
2033 goto done;
2034 /*
2035 * We want the first attribute extent so that we can update the
2036 * data size.
2037 */
2038 vcn = 0;
2039 }
2040 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
2041 CASE_SENSITIVE, vcn, NULL, 0, ctx);
2042 if (unlikely(err)) {
2043 if (err == -ENOENT)
2044 err = -EIO;
2045 goto err_out;
2046 }
2047 m = ctx->mrec;
2048 a = ctx->attr;
2049 /* Use goto to reduce indentation. */
2050 if (a->non_resident)
2051 goto do_non_resident_extend;
2052 BUG_ON(NInoNonResident(ni));
2053 /* The total length of the attribute value. */
2054 attr_len = le32_to_cpu(a->data.resident.value_length);
2055 /*
2056 * Extend the attribute record to be able to store the new attribute
2057 * size. ntfs_attr_record_resize() will not do anything if the size is
2058 * not changing.
2059 */
2060 if (new_alloc_size < vol->mft_record_size &&
2061 !ntfs_attr_record_resize(m, a,
2062 le16_to_cpu(a->data.resident.value_offset) +
2063 new_alloc_size)) {
2064 /* The resize succeeded! */
2065 write_lock_irqsave(&ni->size_lock, flags);
2066 ni->allocated_size = le32_to_cpu(a->length) -
2067 le16_to_cpu(a->data.resident.value_offset);
2068 write_unlock_irqrestore(&ni->size_lock, flags);
2069 if (new_data_size >= 0) {
2070 BUG_ON(new_data_size < attr_len);
2071 a->data.resident.value_length =
2072 cpu_to_le32((u32)new_data_size);
2073 }
2074 goto flush_done;
2075 }
2076 /*
2077 * We have to drop all the locks so we can call
2078 * ntfs_attr_make_non_resident(). This could be optimised by try-
2079 * locking the first page cache page and only if that fails dropping
2080 * the locks, locking the page, and redoing all the locking and
2081 * lookups. While this would be a huge optimisation, it is not worth
2082 * it as this is definitely a slow code path.
2083 */
2084 ntfs_attr_put_search_ctx(ctx);
2085 unmap_mft_record(base_ni);
2086 up_write(&ni->runlist.lock);
2087 /*
2088 * Not enough space in the mft record, try to make the attribute
2089 * non-resident and if successful restart the extension process.
2090 */
2091 err = ntfs_attr_make_non_resident(ni, attr_len);
2092 if (likely(!err))
2093 goto retry_extend;
2094 /*
2095 * Could not make non-resident. If this is due to this not being
2096 * permitted for this attribute type or there not being enough space,
2097 * try to make other attributes non-resident. Otherwise fail.
2098 */
2099 if (unlikely(err != -EPERM && err != -ENOSPC)) {
2100 /* Only emit errors when the write will fail completely. */
2101 read_lock_irqsave(&ni->size_lock, flags);
2102 allocated_size = ni->allocated_size;
2103 read_unlock_irqrestore(&ni->size_lock, flags);
2104 if (start < 0 || start >= allocated_size)
2105 ntfs_error(vol->sb, "Cannot extend allocation of "
2106 "inode 0x%lx, attribute type 0x%x, "
2107 "because the conversion from resident "
2108 "to non-resident attribute failed "
2109 "with error code %i.", vi->i_ino,
2110 (unsigned)le32_to_cpu(ni->type), err);
2111 if (err != -ENOMEM)
2112 err = -EIO;
2113 goto conv_err_out;
2114 }
2115 /* TODO: Not implemented from here, abort. */
2116 read_lock_irqsave(&ni->size_lock, flags);
2117 allocated_size = ni->allocated_size;
2118 read_unlock_irqrestore(&ni->size_lock, flags);
2119 if (start < 0 || start >= allocated_size) {
2120 if (err == -ENOSPC)
2121 ntfs_error(vol->sb, "Not enough space in the mft "
2122 "record/on disk for the non-resident "
2123 "attribute value. This case is not "
2124 "implemented yet.");
2125 else /* if (err == -EPERM) */
2126 ntfs_error(vol->sb, "This attribute type may not be "
2127 "non-resident. This case is not "
2128 "implemented yet.");
2129 }
2130 err = -EOPNOTSUPP;
2131 goto conv_err_out;
2132#if 0
2133 // TODO: Attempt to make other attributes non-resident.
2134 if (!err)
2135 goto do_resident_extend;
2136 /*
2137 * Both the attribute list attribute and the standard information
2138 * attribute must remain in the base inode. Thus, if this is one of
2139 * these attributes, we have to try to move other attributes out into
2140 * extent mft records instead.
2141 */
2142 if (ni->type == AT_ATTRIBUTE_LIST ||
2143 ni->type == AT_STANDARD_INFORMATION) {
2144 // TODO: Attempt to move other attributes into extent mft
2145 // records.
2146 err = -EOPNOTSUPP;
2147 if (!err)
2148 goto do_resident_extend;
2149 goto err_out;
2150 }
2151 // TODO: Attempt to move this attribute to an extent mft record, but
2152 // only if it is not already the only attribute in an mft record in
2153 // which case there would be nothing to gain.
2154 err = -EOPNOTSUPP;
2155 if (!err)
2156 goto do_resident_extend;
2157 /* There is nothing we can do to make enough space. )-: */
2158 goto err_out;
2159#endif
2160do_non_resident_extend:
2161 BUG_ON(!NInoNonResident(ni));
2162 if (new_alloc_size == allocated_size) {
2163 BUG_ON(vcn);
2164 goto alloc_done;
2165 }
2166 /*
2167 * If the data starts after the end of the old allocation, this is a
2168 * $DATA attribute and sparse attributes are enabled on the volume and
2169 * for this inode, then create a sparse region between the old
2170 * allocated size and the start of the data. Otherwise simply proceed
2171 * with filling the whole space between the old allocated size and the
2172 * new allocated size with clusters.
2173 */
2174 if ((start >= 0 && start <= allocated_size) || ni->type != AT_DATA ||
2175 !NVolSparseEnabled(vol) || NInoSparseDisabled(ni))
2176 goto skip_sparse;
2177 // TODO: This is not implemented yet. We just fill in with real
2178 // clusters for now...
2179 ntfs_debug("Inserting holes is not-implemented yet. Falling back to "
2180 "allocating real clusters instead.");
2181skip_sparse:
2182 rl = ni->runlist.rl;
2183 if (likely(rl)) {
2184 /* Seek to the end of the runlist. */
2185 while (rl->length)
2186 rl++;
2187 }
2188 /* If this attribute extent is not mapped, map it now. */
2189 if (unlikely(!rl || rl->lcn == LCN_RL_NOT_MAPPED ||
2190 (rl->lcn == LCN_ENOENT && rl > ni->runlist.rl &&
2191 (rl-1)->lcn == LCN_RL_NOT_MAPPED))) {
2192 if (!rl && !allocated_size)
2193 goto first_alloc;
2194 rl = ntfs_mapping_pairs_decompress(vol, a, ni->runlist.rl);
2195 if (IS_ERR(rl)) {
2196 err = PTR_ERR(rl);
2197 if (start < 0 || start >= allocated_size)
2198 ntfs_error(vol->sb, "Cannot extend allocation "
2199 "of inode 0x%lx, attribute "
2200 "type 0x%x, because the "
2201 "mapping of a runlist "
2202 "fragment failed with error "
2203 "code %i.", vi->i_ino,
2204 (unsigned)le32_to_cpu(ni->type),
2205 err);
2206 if (err != -ENOMEM)
2207 err = -EIO;
2208 goto err_out;
2209 }
2210 ni->runlist.rl = rl;
2211 /* Seek to the end of the runlist. */
2212 while (rl->length)
2213 rl++;
2214 }
2215 /*
2216 * We now know the runlist of the last extent is mapped and @rl is at
2217 * the end of the runlist. We want to begin allocating clusters
2218 * starting at the last allocated cluster to reduce fragmentation. If
2219 * there are no valid LCNs in the attribute we let the cluster
2220 * allocator choose the starting cluster.
2221 */
2222 /* If the last LCN is a hole or simillar seek back to last real LCN. */
2223 while (rl->lcn < 0 && rl > ni->runlist.rl)
2224 rl--;
2225first_alloc:
2226 // FIXME: Need to implement partial allocations so at least part of the
2227 // write can be performed when start >= 0. (Needed for POSIX write(2)
2228 // conformance.)
2229 rl2 = ntfs_cluster_alloc(vol, allocated_size >> vol->cluster_size_bits,
2230 (new_alloc_size - allocated_size) >>
2231 vol->cluster_size_bits, (rl && (rl->lcn >= 0)) ?
2232 rl->lcn + rl->length : -1, DATA_ZONE, true);
2233 if (IS_ERR(rl2)) {
2234 err = PTR_ERR(rl2);
2235 if (start < 0 || start >= allocated_size)
2236 ntfs_error(vol->sb, "Cannot extend allocation of "
2237 "inode 0x%lx, attribute type 0x%x, "
2238 "because the allocation of clusters "
2239 "failed with error code %i.", vi->i_ino,
2240 (unsigned)le32_to_cpu(ni->type), err);
2241 if (err != -ENOMEM && err != -ENOSPC)
2242 err = -EIO;
2243 goto err_out;
2244 }
2245 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
2246 if (IS_ERR(rl)) {
2247 err = PTR_ERR(rl);
2248 if (start < 0 || start >= allocated_size)
2249 ntfs_error(vol->sb, "Cannot extend allocation of "
2250 "inode 0x%lx, attribute type 0x%x, "
2251 "because the runlist merge failed "
2252 "with error code %i.", vi->i_ino,
2253 (unsigned)le32_to_cpu(ni->type), err);
2254 if (err != -ENOMEM)
2255 err = -EIO;
2256 if (ntfs_cluster_free_from_rl(vol, rl2)) {
2257 ntfs_error(vol->sb, "Failed to release allocated "
2258 "cluster(s) in error code path. Run "
2259 "chkdsk to recover the lost "
2260 "cluster(s).");
2261 NVolSetErrors(vol);
2262 }
2263 ntfs_free(rl2);
2264 goto err_out;
2265 }
2266 ni->runlist.rl = rl;
2267 ntfs_debug("Allocated 0x%llx clusters.", (long long)(new_alloc_size -
2268 allocated_size) >> vol->cluster_size_bits);
2269 /* Find the runlist element with which the attribute extent starts. */
2270 ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
2271 rl2 = ntfs_rl_find_vcn_nolock(rl, ll);
2272 BUG_ON(!rl2);
2273 BUG_ON(!rl2->length);
2274 BUG_ON(rl2->lcn < LCN_HOLE);
2275 mp_rebuilt = false;
2276 /* Get the size for the new mapping pairs array for this extent. */
2277 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
2278 if (unlikely(mp_size <= 0)) {
2279 err = mp_size;
2280 if (start < 0 || start >= allocated_size)
2281 ntfs_error(vol->sb, "Cannot extend allocation of "
2282 "inode 0x%lx, attribute type 0x%x, "
2283 "because determining the size for the "
2284 "mapping pairs failed with error code "
2285 "%i.", vi->i_ino,
2286 (unsigned)le32_to_cpu(ni->type), err);
2287 err = -EIO;
2288 goto undo_alloc;
2289 }
2290 /* Extend the attribute record to fit the bigger mapping pairs array. */
2291 attr_len = le32_to_cpu(a->length);
2292 err = ntfs_attr_record_resize(m, a, mp_size +
2293 le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
2294 if (unlikely(err)) {
2295 BUG_ON(err != -ENOSPC);
2296 // TODO: Deal with this by moving this extent to a new mft
2297 // record or by starting a new extent in a new mft record,
2298 // possibly by extending this extent partially and filling it
2299 // and creating a new extent for the remainder, or by making
2300 // other attributes non-resident and/or by moving other
2301 // attributes out of this mft record.
2302 if (start < 0 || start >= allocated_size)
2303 ntfs_error(vol->sb, "Not enough space in the mft "
2304 "record for the extended attribute "
2305 "record. This case is not "
2306 "implemented yet.");
2307 err = -EOPNOTSUPP;
2308 goto undo_alloc;
2309 }
2310 mp_rebuilt = true;
2311 /* Generate the mapping pairs array directly into the attr record. */
2312 err = ntfs_mapping_pairs_build(vol, (u8*)a +
2313 le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
2314 mp_size, rl2, ll, -1, NULL);
2315 if (unlikely(err)) {
2316 if (start < 0 || start >= allocated_size)
2317 ntfs_error(vol->sb, "Cannot extend allocation of "
2318 "inode 0x%lx, attribute type 0x%x, "
2319 "because building the mapping pairs "
2320 "failed with error code %i.", vi->i_ino,
2321 (unsigned)le32_to_cpu(ni->type), err);
2322 err = -EIO;
2323 goto undo_alloc;
2324 }
2325 /* Update the highest_vcn. */
2326 a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >>
2327 vol->cluster_size_bits) - 1);
2328 /*
2329 * We now have extended the allocated size of the attribute. Reflect
2330 * this in the ntfs_inode structure and the attribute record.
2331 */
2332 if (a->data.non_resident.lowest_vcn) {
2333 /*
2334 * We are not in the first attribute extent, switch to it, but
2335 * first ensure the changes will make it to disk later.
2336 */
2337 flush_dcache_mft_record_page(ctx->ntfs_ino);
2338 mark_mft_record_dirty(ctx->ntfs_ino);
2339 ntfs_attr_reinit_search_ctx(ctx);
2340 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
2341 CASE_SENSITIVE, 0, NULL, 0, ctx);
2342 if (unlikely(err))
2343 goto restore_undo_alloc;
2344 /* @m is not used any more so no need to set it. */
2345 a = ctx->attr;
2346 }
2347 write_lock_irqsave(&ni->size_lock, flags);
2348 ni->allocated_size = new_alloc_size;
2349 a->data.non_resident.allocated_size = cpu_to_sle64(new_alloc_size);
2350 /*
2351 * FIXME: This would fail if @ni is a directory, $MFT, or an index,
2352 * since those can have sparse/compressed set. For example can be
2353 * set compressed even though it is not compressed itself and in that
2354 * case the bit means that files are to be created compressed in the
2355 * directory... At present this is ok as this code is only called for
2356 * regular files, and only for their $DATA attribute(s).
2357 * FIXME: The calculation is wrong if we created a hole above. For now
2358 * it does not matter as we never create holes.
2359 */
2360 if (NInoSparse(ni) || NInoCompressed(ni)) {
2361 ni->itype.compressed.size += new_alloc_size - allocated_size;
2362 a->data.non_resident.compressed_size =
2363 cpu_to_sle64(ni->itype.compressed.size);
2364 vi->i_blocks = ni->itype.compressed.size >> 9;
2365 } else
2366 vi->i_blocks = new_alloc_size >> 9;
2367 write_unlock_irqrestore(&ni->size_lock, flags);
2368alloc_done:
2369 if (new_data_size >= 0) {
2370 BUG_ON(new_data_size <
2371 sle64_to_cpu(a->data.non_resident.data_size));
2372 a->data.non_resident.data_size = cpu_to_sle64(new_data_size);
2373 }
2374flush_done:
2375 /* Ensure the changes make it to disk. */
2376 flush_dcache_mft_record_page(ctx->ntfs_ino);
2377 mark_mft_record_dirty(ctx->ntfs_ino);
2378done:
2379 ntfs_attr_put_search_ctx(ctx);
2380 unmap_mft_record(base_ni);
2381 up_write(&ni->runlist.lock);
2382 ntfs_debug("Done, new_allocated_size 0x%llx.",
2383 (unsigned long long)new_alloc_size);
2384 return new_alloc_size;
2385restore_undo_alloc:
2386 if (start < 0 || start >= allocated_size)
2387 ntfs_error(vol->sb, "Cannot complete extension of allocation "
2388 "of inode 0x%lx, attribute type 0x%x, because "
2389 "lookup of first attribute extent failed with "
2390 "error code %i.", vi->i_ino,
2391 (unsigned)le32_to_cpu(ni->type), err);
2392 if (err == -ENOENT)
2393 err = -EIO;
2394 ntfs_attr_reinit_search_ctx(ctx);
2395 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
2396 allocated_size >> vol->cluster_size_bits, NULL, 0,
2397 ctx)) {
2398 ntfs_error(vol->sb, "Failed to find last attribute extent of "
2399 "attribute in error code path. Run chkdsk to "
2400 "recover.");
2401 write_lock_irqsave(&ni->size_lock, flags);
2402 ni->allocated_size = new_alloc_size;
2403 /*
2404 * FIXME: This would fail if @ni is a directory... See above.
2405 * FIXME: The calculation is wrong if we created a hole above.
2406 * For now it does not matter as we never create holes.
2407 */
2408 if (NInoSparse(ni) || NInoCompressed(ni)) {
2409 ni->itype.compressed.size += new_alloc_size -
2410 allocated_size;
2411 vi->i_blocks = ni->itype.compressed.size >> 9;
2412 } else
2413 vi->i_blocks = new_alloc_size >> 9;
2414 write_unlock_irqrestore(&ni->size_lock, flags);
2415 ntfs_attr_put_search_ctx(ctx);
2416 unmap_mft_record(base_ni);
2417 up_write(&ni->runlist.lock);
2418 /*
2419 * The only thing that is now wrong is the allocated size of the
2420 * base attribute extent which chkdsk should be able to fix.
2421 */
2422 NVolSetErrors(vol);
2423 return err;
2424 }
2425 ctx->attr->data.non_resident.highest_vcn = cpu_to_sle64(
2426 (allocated_size >> vol->cluster_size_bits) - 1);
2427undo_alloc:
2428 ll = allocated_size >> vol->cluster_size_bits;
2429 if (ntfs_cluster_free(ni, ll, -1, ctx) < 0) {
2430 ntfs_error(vol->sb, "Failed to release allocated cluster(s) "
2431 "in error code path. Run chkdsk to recover "
2432 "the lost cluster(s).");
2433 NVolSetErrors(vol);
2434 }
2435 m = ctx->mrec;
2436 a = ctx->attr;
2437 /*
2438 * If the runlist truncation fails and/or the search context is no
2439 * longer valid, we cannot resize the attribute record or build the
2440 * mapping pairs array thus we mark the inode bad so that no access to
2441 * the freed clusters can happen.
2442 */
2443 if (ntfs_rl_truncate_nolock(vol, &ni->runlist, ll) || IS_ERR(m)) {
2444 ntfs_error(vol->sb, "Failed to %s in error code path. Run "
2445 "chkdsk to recover.", IS_ERR(m) ?
2446 "restore attribute search context" :
2447 "truncate attribute runlist");
2448 NVolSetErrors(vol);
2449 } else if (mp_rebuilt) {
2450 if (ntfs_attr_record_resize(m, a, attr_len)) {
2451 ntfs_error(vol->sb, "Failed to restore attribute "
2452 "record in error code path. Run "
2453 "chkdsk to recover.");
2454 NVolSetErrors(vol);
2455 } else /* if (success) */ {
2456 if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
2457 a->data.non_resident.
2458 mapping_pairs_offset), attr_len -
2459 le16_to_cpu(a->data.non_resident.
2460 mapping_pairs_offset), rl2, ll, -1,
2461 NULL)) {
2462 ntfs_error(vol->sb, "Failed to restore "
2463 "mapping pairs array in error "
2464 "code path. Run chkdsk to "
2465 "recover.");
2466 NVolSetErrors(vol);
2467 }
2468 flush_dcache_mft_record_page(ctx->ntfs_ino);
2469 mark_mft_record_dirty(ctx->ntfs_ino);
2470 }
2471 }
2472err_out:
2473 if (ctx)
2474 ntfs_attr_put_search_ctx(ctx);
2475 if (m)
2476 unmap_mft_record(base_ni);
2477 up_write(&ni->runlist.lock);
2478conv_err_out:
2479 ntfs_debug("Failed. Returning error code %i.", err);
2480 return err;
2481}
2482
2483/**
2484 * ntfs_attr_set - fill (a part of) an attribute with a byte
2485 * @ni: ntfs inode describing the attribute to fill
2486 * @ofs: offset inside the attribute at which to start to fill
2487 * @cnt: number of bytes to fill
2488 * @val: the unsigned 8-bit value with which to fill the attribute
2489 *
2490 * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
2491 * byte offset @ofs inside the attribute with the constant byte @val.
2492 *
2493 * This function is effectively like memset() applied to an ntfs attribute.
2494 * Note thie function actually only operates on the page cache pages belonging
2495 * to the ntfs attribute and it marks them dirty after doing the memset().
2496 * Thus it relies on the vm dirty page write code paths to cause the modified
2497 * pages to be written to the mft record/disk.
2498 *
2499 * Return 0 on success and -errno on error. An error code of -ESPIPE means
2500 * that @ofs + @cnt were outside the end of the attribute and no write was
2501 * performed.
2502 */
2503int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
2504{
2505 ntfs_volume *vol = ni->vol;
2506 struct address_space *mapping;
2507 struct page *page;
2508 u8 *kaddr;
2509 pgoff_t idx, end;
2510 unsigned start_ofs, end_ofs, size;
2511
2512 ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.",
2513 (long long)ofs, (long long)cnt, val);
2514 BUG_ON(ofs < 0);
2515 BUG_ON(cnt < 0);
2516 if (!cnt)
2517 goto done;
2518 /*
2519 * FIXME: Compressed and encrypted attributes are not supported when
2520 * writing and we should never have gotten here for them.
2521 */
2522 BUG_ON(NInoCompressed(ni));
2523 BUG_ON(NInoEncrypted(ni));
2524 mapping = VFS_I(ni)->i_mapping;
2525 /* Work out the starting index and page offset. */
2526 idx = ofs >> PAGE_SHIFT;
2527 start_ofs = ofs & ~PAGE_MASK;
2528 /* Work out the ending index and page offset. */
2529 end = ofs + cnt;
2530 end_ofs = end & ~PAGE_MASK;
2531 /* If the end is outside the inode size return -ESPIPE. */
2532 if (unlikely(end > i_size_read(VFS_I(ni)))) {
2533 ntfs_error(vol->sb, "Request exceeds end of attribute.");
2534 return -ESPIPE;
2535 }
2536 end >>= PAGE_SHIFT;
2537 /* If there is a first partial page, need to do it the slow way. */
2538 if (start_ofs) {
2539 page = read_mapping_page(mapping, idx, NULL);
2540 if (IS_ERR(page)) {
2541 ntfs_error(vol->sb, "Failed to read first partial "
2542 "page (error, index 0x%lx).", idx);
2543 return PTR_ERR(page);
2544 }
2545 /*
2546 * If the last page is the same as the first page, need to
2547 * limit the write to the end offset.
2548 */
2549 size = PAGE_SIZE;
2550 if (idx == end)
2551 size = end_ofs;
2552 kaddr = kmap_atomic(page);
2553 memset(kaddr + start_ofs, val, size - start_ofs);
2554 flush_dcache_page(page);
2555 kunmap_atomic(kaddr);
2556 set_page_dirty(page);
2557 put_page(page);
2558 balance_dirty_pages_ratelimited(mapping);
2559 cond_resched();
2560 if (idx == end)
2561 goto done;
2562 idx++;
2563 }
2564 /* Do the whole pages the fast way. */
2565 for (; idx < end; idx++) {
2566 /* Find or create the current page. (The page is locked.) */
2567 page = grab_cache_page(mapping, idx);
2568 if (unlikely(!page)) {
2569 ntfs_error(vol->sb, "Insufficient memory to grab "
2570 "page (index 0x%lx).", idx);
2571 return -ENOMEM;
2572 }
2573 kaddr = kmap_atomic(page);
2574 memset(kaddr, val, PAGE_SIZE);
2575 flush_dcache_page(page);
2576 kunmap_atomic(kaddr);
2577 /*
2578 * If the page has buffers, mark them uptodate since buffer
2579 * state and not page state is definitive in 2.6 kernels.
2580 */
2581 if (page_has_buffers(page)) {
2582 struct buffer_head *bh, *head;
2583
2584 bh = head = page_buffers(page);
2585 do {
2586 set_buffer_uptodate(bh);
2587 } while ((bh = bh->b_this_page) != head);
2588 }
2589 /* Now that buffers are uptodate, set the page uptodate, too. */
2590 SetPageUptodate(page);
2591 /*
2592 * Set the page and all its buffers dirty and mark the inode
2593 * dirty, too. The VM will write the page later on.
2594 */
2595 set_page_dirty(page);
2596 /* Finally unlock and release the page. */
2597 unlock_page(page);
2598 put_page(page);
2599 balance_dirty_pages_ratelimited(mapping);
2600 cond_resched();
2601 }
2602 /* If there is a last partial page, need to do it the slow way. */
2603 if (end_ofs) {
2604 page = read_mapping_page(mapping, idx, NULL);
2605 if (IS_ERR(page)) {
2606 ntfs_error(vol->sb, "Failed to read last partial page "
2607 "(error, index 0x%lx).", idx);
2608 return PTR_ERR(page);
2609 }
2610 kaddr = kmap_atomic(page);
2611 memset(kaddr, val, end_ofs);
2612 flush_dcache_page(page);
2613 kunmap_atomic(kaddr);
2614 set_page_dirty(page);
2615 put_page(page);
2616 balance_dirty_pages_ratelimited(mapping);
2617 cond_resched();
2618 }
2619done:
2620 ntfs_debug("Done.");
2621 return 0;
2622}
2623
2624#endif /* NTFS_RW */