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v6.9.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *
  4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
  5 *
  6 */
  7
  8#include <linux/fs.h>
  9
 10#include "debug.h"
 11#include "ntfs.h"
 12#include "ntfs_fs.h"
 13
 14static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
 15			       const __le16 *name, u8 name_len,
 16			       const u16 *upcase)
 17{
 18	/* First, compare the type codes. */
 19	int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
 20
 21	if (diff)
 22		return diff;
 23
 24	/* They have the same type code, so we have to compare the names. */
 25	return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
 26			      upcase, true);
 27}
 28
 29/*
 30 * mi_new_attt_id
 31 *
 32 * Return: Unused attribute id that is less than mrec->next_attr_id.
 33 */
 34static __le16 mi_new_attt_id(struct mft_inode *mi)
 35{
 36	u16 free_id, max_id, t16;
 37	struct MFT_REC *rec = mi->mrec;
 38	struct ATTRIB *attr;
 39	__le16 id;
 40
 41	id = rec->next_attr_id;
 42	free_id = le16_to_cpu(id);
 43	if (free_id < 0x7FFF) {
 44		rec->next_attr_id = cpu_to_le16(free_id + 1);
 45		return id;
 46	}
 47
 48	/* One record can store up to 1024/24 ~= 42 attributes. */
 49	free_id = 0;
 50	max_id = 0;
 51
 52	attr = NULL;
 53
 54	for (;;) {
 55		attr = mi_enum_attr(mi, attr);
 56		if (!attr) {
 57			rec->next_attr_id = cpu_to_le16(max_id + 1);
 58			mi->dirty = true;
 59			return cpu_to_le16(free_id);
 60		}
 61
 62		t16 = le16_to_cpu(attr->id);
 63		if (t16 == free_id) {
 64			free_id += 1;
 65			attr = NULL;
 66		} else if (max_id < t16)
 67			max_id = t16;
 68	}
 69}
 70
 71int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
 72{
 73	int err;
 74	struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
 75
 76	if (!m)
 77		return -ENOMEM;
 78
 79	err = mi_init(m, sbi, rno);
 80	if (err) {
 81		kfree(m);
 82		return err;
 83	}
 84
 85	err = mi_read(m, false);
 86	if (err) {
 87		mi_put(m);
 88		return err;
 89	}
 90
 91	*mi = m;
 92	return 0;
 93}
 94
 95void mi_put(struct mft_inode *mi)
 96{
 97	mi_clear(mi);
 98	kfree(mi);
 99}
100
101int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
102{
103	mi->sbi = sbi;
104	mi->rno = rno;
105	mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
106	if (!mi->mrec)
107		return -ENOMEM;
108
109	return 0;
110}
111
112/*
113 * mi_read - Read MFT data.
114 */
115int mi_read(struct mft_inode *mi, bool is_mft)
116{
117	int err;
118	struct MFT_REC *rec = mi->mrec;
119	struct ntfs_sb_info *sbi = mi->sbi;
120	u32 bpr = sbi->record_size;
121	u64 vbo = (u64)mi->rno << sbi->record_bits;
122	struct ntfs_inode *mft_ni = sbi->mft.ni;
123	struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
124	struct rw_semaphore *rw_lock = NULL;
125
126	if (is_mounted(sbi)) {
127		if (!is_mft && mft_ni) {
128			rw_lock = &mft_ni->file.run_lock;
129			down_read(rw_lock);
130		}
131	}
132
133	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
134	if (rw_lock)
135		up_read(rw_lock);
136	if (!err)
137		goto ok;
138
139	if (err == -E_NTFS_FIXUP) {
140		mi->dirty = true;
141		goto ok;
142	}
143
144	if (err != -ENOENT)
145		goto out;
146
147	if (rw_lock) {
148		ni_lock(mft_ni);
149		down_write(rw_lock);
150	}
151	err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run,
152				 vbo >> sbi->cluster_bits);
153	if (rw_lock) {
154		up_write(rw_lock);
155		ni_unlock(mft_ni);
156	}
157	if (err)
158		goto out;
159
160	if (rw_lock)
161		down_read(rw_lock);
162	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
163	if (rw_lock)
164		up_read(rw_lock);
165
166	if (err == -E_NTFS_FIXUP) {
167		mi->dirty = true;
168		goto ok;
169	}
170	if (err)
171		goto out;
172
173ok:
174	/* Check field 'total' only here. */
175	if (le32_to_cpu(rec->total) != bpr) {
176		err = -EINVAL;
177		goto out;
178	}
179
180	return 0;
181
182out:
183	if (err == -E_NTFS_CORRUPT) {
184		ntfs_err(sbi->sb, "mft corrupted");
185		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
186		err = -EINVAL;
187	}
188
189	return err;
190}
191
192/*
193 * mi_enum_attr - start/continue attributes enumeration in record.
194 *
195 * NOTE: mi->mrec - memory of size sbi->record_size
196 * here we sure that mi->mrec->total == sbi->record_size (see mi_read)
197 */
198struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
199{
200	const struct MFT_REC *rec = mi->mrec;
201	u32 used = le32_to_cpu(rec->used);
202	u32 t32, off, asize, prev_type;
203	u16 t16;
204	u64 data_size, alloc_size, tot_size;
205
206	if (!attr) {
207		u32 total = le32_to_cpu(rec->total);
208
209		off = le16_to_cpu(rec->attr_off);
210
211		if (used > total)
212			return NULL;
213
214		if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
215		    !IS_ALIGNED(off, 4)) {
216			return NULL;
217		}
218
219		/* Skip non-resident records. */
220		if (!is_rec_inuse(rec))
221			return NULL;
222
223		prev_type = 0;
224		attr = Add2Ptr(rec, off);
225	} else {
226		/* Check if input attr inside record. */
227		off = PtrOffset(rec, attr);
228		if (off >= used)
229			return NULL;
230
231		asize = le32_to_cpu(attr->size);
232		if (asize < SIZEOF_RESIDENT) {
233			/* Impossible 'cause we should not return such attribute. */
234			return NULL;
235		}
236
237		/* Overflow check. */
238		if (off + asize < off)
239			return NULL;
240
241		prev_type = le32_to_cpu(attr->type);
242		attr = Add2Ptr(attr, asize);
243		off += asize;
244	}
245
246	asize = le32_to_cpu(attr->size);
247
248	/* Can we use the first field (attr->type). */
249	if (off + 8 > used) {
250		static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
251		return NULL;
252	}
253
254	if (attr->type == ATTR_END) {
255		/* End of enumeration. */
256		return NULL;
257	}
258
259	/* 0x100 is last known attribute for now. */
260	t32 = le32_to_cpu(attr->type);
261	if (!t32 || (t32 & 0xf) || (t32 > 0x100))
262		return NULL;
263
264	/* attributes in record must be ordered by type */
265	if (t32 < prev_type)
266		return NULL;
267
268	/* Check overflow and boundary. */
269	if (off + asize < off || off + asize > used)
270		return NULL;
271
272	/* Check size of attribute. */
273	if (!attr->non_res) {
274		/* Check resident fields. */
275		if (asize < SIZEOF_RESIDENT)
276			return NULL;
277
278		t16 = le16_to_cpu(attr->res.data_off);
279		if (t16 > asize)
280			return NULL;
281
282		if (le32_to_cpu(attr->res.data_size) > asize - t16)
283			return NULL;
284
285		t32 = sizeof(short) * attr->name_len;
286		if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
287			return NULL;
288
289		return attr;
290	}
291
292	/* Check nonresident fields. */
293	if (attr->non_res != 1)
294		return NULL;
295
296	t16 = le16_to_cpu(attr->nres.run_off);
297	if (t16 > asize)
298		return NULL;
299
300	t32 = sizeof(short) * attr->name_len;
301	if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
302		return NULL;
303
304	/* Check start/end vcn. */
305	if (le64_to_cpu(attr->nres.svcn) > le64_to_cpu(attr->nres.evcn) + 1)
306		return NULL;
307
308	data_size = le64_to_cpu(attr->nres.data_size);
309	if (le64_to_cpu(attr->nres.valid_size) > data_size)
310		return NULL;
311
312	alloc_size = le64_to_cpu(attr->nres.alloc_size);
313	if (data_size > alloc_size)
314		return NULL;
315
316	t32 = mi->sbi->cluster_mask;
317	if (alloc_size & t32)
318		return NULL;
319
320	if (!attr->nres.svcn && is_attr_ext(attr)) {
321		/* First segment of sparse/compressed attribute */
322		if (asize + 8 < SIZEOF_NONRESIDENT_EX)
323			return NULL;
324
325		tot_size = le64_to_cpu(attr->nres.total_size);
326		if (tot_size & t32)
327			return NULL;
328
329		if (tot_size > alloc_size)
330			return NULL;
331	} else {
332		if (asize + 8 < SIZEOF_NONRESIDENT)
333			return NULL;
334
335		if (attr->nres.c_unit)
336			return NULL;
337	}
338
339	return attr;
340}
341
342/*
343 * mi_find_attr - Find the attribute by type and name and id.
344 */
345struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
346			    enum ATTR_TYPE type, const __le16 *name,
347			    u8 name_len, const __le16 *id)
348{
349	u32 type_in = le32_to_cpu(type);
350	u32 atype;
351
352next_attr:
353	attr = mi_enum_attr(mi, attr);
354	if (!attr)
355		return NULL;
356
357	atype = le32_to_cpu(attr->type);
358	if (atype > type_in)
359		return NULL;
360
361	if (atype < type_in)
362		goto next_attr;
363
364	if (attr->name_len != name_len)
365		goto next_attr;
366
367	if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
368		goto next_attr;
369
370	if (id && *id != attr->id)
371		goto next_attr;
372
373	return attr;
374}
375
376int mi_write(struct mft_inode *mi, int wait)
377{
378	struct MFT_REC *rec;
379	int err;
380	struct ntfs_sb_info *sbi;
381
382	if (!mi->dirty)
383		return 0;
384
385	sbi = mi->sbi;
386	rec = mi->mrec;
387
388	err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
389	if (err)
390		return err;
391
392	if (mi->rno < sbi->mft.recs_mirr)
393		sbi->flags |= NTFS_FLAGS_MFTMIRR;
394
395	mi->dirty = false;
396
397	return 0;
398}
399
400int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
401		  __le16 flags, bool is_mft)
402{
403	int err;
404	u16 seq = 1;
405	struct MFT_REC *rec;
406	u64 vbo = (u64)rno << sbi->record_bits;
407
408	err = mi_init(mi, sbi, rno);
409	if (err)
410		return err;
411
412	rec = mi->mrec;
413
414	if (rno == MFT_REC_MFT) {
415		;
416	} else if (rno < MFT_REC_FREE) {
417		seq = rno;
418	} else if (rno >= sbi->mft.used) {
419		;
420	} else if (mi_read(mi, is_mft)) {
421		;
422	} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
423		/* Record is reused. Update its sequence number. */
424		seq = le16_to_cpu(rec->seq) + 1;
425		if (!seq)
426			seq = 1;
427	}
428
429	memcpy(rec, sbi->new_rec, sbi->record_size);
430
431	rec->seq = cpu_to_le16(seq);
432	rec->flags = RECORD_FLAG_IN_USE | flags;
433	if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3)
434		rec->mft_record = cpu_to_le32(rno);
435
436	mi->dirty = true;
437
438	if (!mi->nb.nbufs) {
439		struct ntfs_inode *ni = sbi->mft.ni;
440		bool lock = false;
441
442		if (is_mounted(sbi) && !is_mft) {
443			down_read(&ni->file.run_lock);
444			lock = true;
445		}
446
447		err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
448				  &mi->nb);
449		if (lock)
450			up_read(&ni->file.run_lock);
451	}
452
453	return err;
454}
455
456/*
457 * mi_insert_attr - Reserve space for new attribute.
458 *
459 * Return: Not full constructed attribute or NULL if not possible to create.
460 */
461struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
462			      const __le16 *name, u8 name_len, u32 asize,
463			      u16 name_off)
464{
465	size_t tail;
466	struct ATTRIB *attr;
467	__le16 id;
468	struct MFT_REC *rec = mi->mrec;
469	struct ntfs_sb_info *sbi = mi->sbi;
470	u32 used = le32_to_cpu(rec->used);
471	const u16 *upcase = sbi->upcase;
472
473	/* Can we insert mi attribute? */
474	if (used + asize > sbi->record_size)
475		return NULL;
476
477	/*
478	 * Scan through the list of attributes to find the point
479	 * at which we should insert it.
480	 */
481	attr = NULL;
482	while ((attr = mi_enum_attr(mi, attr))) {
483		int diff = compare_attr(attr, type, name, name_len, upcase);
484
485		if (diff < 0)
486			continue;
487
488		if (!diff && !is_attr_indexed(attr))
489			return NULL;
490		break;
491	}
492
493	if (!attr) {
494		/* Append. */
495		tail = 8;
496		attr = Add2Ptr(rec, used - 8);
497	} else {
498		/* Insert before 'attr'. */
499		tail = used - PtrOffset(rec, attr);
500	}
501
502	id = mi_new_attt_id(mi);
503
504	memmove(Add2Ptr(attr, asize), attr, tail);
505	memset(attr, 0, asize);
506
507	attr->type = type;
508	attr->size = cpu_to_le32(asize);
509	attr->name_len = name_len;
510	attr->name_off = cpu_to_le16(name_off);
511	attr->id = id;
512
513	memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
514	rec->used = cpu_to_le32(used + asize);
515
516	mi->dirty = true;
517
518	return attr;
519}
520
521/*
522 * mi_remove_attr - Remove the attribute from record.
523 *
524 * NOTE: The source attr will point to next attribute.
525 */
526bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
527		    struct ATTRIB *attr)
528{
529	struct MFT_REC *rec = mi->mrec;
530	u32 aoff = PtrOffset(rec, attr);
531	u32 used = le32_to_cpu(rec->used);
532	u32 asize = le32_to_cpu(attr->size);
533
534	if (aoff + asize > used)
535		return false;
536
537	if (ni && is_attr_indexed(attr) && attr->type == ATTR_NAME) {
538		u16 links = le16_to_cpu(ni->mi.mrec->hard_links);
539		if (!links) {
 
 
 
 
 
 
 
540			/* minor error. Not critical. */
541		} else {
542			ni->mi.mrec->hard_links = cpu_to_le16(links - 1);
543			ni->mi.dirty = true;
544		}
545	}
546
547	used -= asize;
548	memmove(attr, Add2Ptr(attr, asize), used - aoff);
549	rec->used = cpu_to_le32(used);
550	mi->dirty = true;
551
552	return true;
553}
554
555/* bytes = "new attribute size" - "old attribute size" */
556bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
557{
558	struct MFT_REC *rec = mi->mrec;
559	u32 aoff = PtrOffset(rec, attr);
560	u32 total, used = le32_to_cpu(rec->used);
561	u32 nsize, asize = le32_to_cpu(attr->size);
562	u32 rsize = le32_to_cpu(attr->res.data_size);
563	int tail = (int)(used - aoff - asize);
564	int dsize;
565	char *next;
566
567	if (tail < 0 || aoff >= used)
568		return false;
569
570	if (!bytes)
571		return true;
572
573	total = le32_to_cpu(rec->total);
574	next = Add2Ptr(attr, asize);
575
576	if (bytes > 0) {
577		dsize = ALIGN(bytes, 8);
578		if (used + dsize > total)
579			return false;
580		nsize = asize + dsize;
581		/* Move tail */
582		memmove(next + dsize, next, tail);
583		memset(next, 0, dsize);
584		used += dsize;
585		rsize += dsize;
586	} else {
587		dsize = ALIGN(-bytes, 8);
588		if (dsize > asize)
589			return false;
590		nsize = asize - dsize;
591		memmove(next - dsize, next, tail);
592		used -= dsize;
593		rsize -= dsize;
594	}
595
596	rec->used = cpu_to_le32(used);
597	attr->size = cpu_to_le32(nsize);
598	if (!attr->non_res)
599		attr->res.data_size = cpu_to_le32(rsize);
600	mi->dirty = true;
601
602	return true;
603}
604
605/*
606 * Pack runs in MFT record.
607 * If failed record is not changed.
608 */
609int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
610		 struct runs_tree *run, CLST len)
611{
612	int err = 0;
613	struct ntfs_sb_info *sbi = mi->sbi;
614	u32 new_run_size;
615	CLST plen;
616	struct MFT_REC *rec = mi->mrec;
617	CLST svcn = le64_to_cpu(attr->nres.svcn);
618	u32 used = le32_to_cpu(rec->used);
619	u32 aoff = PtrOffset(rec, attr);
620	u32 asize = le32_to_cpu(attr->size);
621	char *next = Add2Ptr(attr, asize);
622	u16 run_off = le16_to_cpu(attr->nres.run_off);
623	u32 run_size = asize - run_off;
624	u32 tail = used - aoff - asize;
625	u32 dsize = sbi->record_size - used;
626
627	/* Make a maximum gap in current record. */
628	memmove(next + dsize, next, tail);
629
630	/* Pack as much as possible. */
631	err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
632		       &plen);
633	if (err < 0) {
634		memmove(next, next + dsize, tail);
635		return err;
636	}
637
638	new_run_size = ALIGN(err, 8);
639
640	memmove(next + new_run_size - run_size, next + dsize, tail);
641
642	attr->size = cpu_to_le32(asize + new_run_size - run_size);
643	attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
644	rec->used = cpu_to_le32(used + new_run_size - run_size);
645	mi->dirty = true;
646
647	return 0;
648}
v6.8
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *
  4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
  5 *
  6 */
  7
  8#include <linux/fs.h>
  9
 10#include "debug.h"
 11#include "ntfs.h"
 12#include "ntfs_fs.h"
 13
 14static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
 15			       const __le16 *name, u8 name_len,
 16			       const u16 *upcase)
 17{
 18	/* First, compare the type codes. */
 19	int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
 20
 21	if (diff)
 22		return diff;
 23
 24	/* They have the same type code, so we have to compare the names. */
 25	return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
 26			      upcase, true);
 27}
 28
 29/*
 30 * mi_new_attt_id
 31 *
 32 * Return: Unused attribute id that is less than mrec->next_attr_id.
 33 */
 34static __le16 mi_new_attt_id(struct mft_inode *mi)
 35{
 36	u16 free_id, max_id, t16;
 37	struct MFT_REC *rec = mi->mrec;
 38	struct ATTRIB *attr;
 39	__le16 id;
 40
 41	id = rec->next_attr_id;
 42	free_id = le16_to_cpu(id);
 43	if (free_id < 0x7FFF) {
 44		rec->next_attr_id = cpu_to_le16(free_id + 1);
 45		return id;
 46	}
 47
 48	/* One record can store up to 1024/24 ~= 42 attributes. */
 49	free_id = 0;
 50	max_id = 0;
 51
 52	attr = NULL;
 53
 54	for (;;) {
 55		attr = mi_enum_attr(mi, attr);
 56		if (!attr) {
 57			rec->next_attr_id = cpu_to_le16(max_id + 1);
 58			mi->dirty = true;
 59			return cpu_to_le16(free_id);
 60		}
 61
 62		t16 = le16_to_cpu(attr->id);
 63		if (t16 == free_id) {
 64			free_id += 1;
 65			attr = NULL;
 66		} else if (max_id < t16)
 67			max_id = t16;
 68	}
 69}
 70
 71int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
 72{
 73	int err;
 74	struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
 75
 76	if (!m)
 77		return -ENOMEM;
 78
 79	err = mi_init(m, sbi, rno);
 80	if (err) {
 81		kfree(m);
 82		return err;
 83	}
 84
 85	err = mi_read(m, false);
 86	if (err) {
 87		mi_put(m);
 88		return err;
 89	}
 90
 91	*mi = m;
 92	return 0;
 93}
 94
 95void mi_put(struct mft_inode *mi)
 96{
 97	mi_clear(mi);
 98	kfree(mi);
 99}
100
101int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
102{
103	mi->sbi = sbi;
104	mi->rno = rno;
105	mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
106	if (!mi->mrec)
107		return -ENOMEM;
108
109	return 0;
110}
111
112/*
113 * mi_read - Read MFT data.
114 */
115int mi_read(struct mft_inode *mi, bool is_mft)
116{
117	int err;
118	struct MFT_REC *rec = mi->mrec;
119	struct ntfs_sb_info *sbi = mi->sbi;
120	u32 bpr = sbi->record_size;
121	u64 vbo = (u64)mi->rno << sbi->record_bits;
122	struct ntfs_inode *mft_ni = sbi->mft.ni;
123	struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
124	struct rw_semaphore *rw_lock = NULL;
125
126	if (is_mounted(sbi)) {
127		if (!is_mft && mft_ni) {
128			rw_lock = &mft_ni->file.run_lock;
129			down_read(rw_lock);
130		}
131	}
132
133	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
134	if (rw_lock)
135		up_read(rw_lock);
136	if (!err)
137		goto ok;
138
139	if (err == -E_NTFS_FIXUP) {
140		mi->dirty = true;
141		goto ok;
142	}
143
144	if (err != -ENOENT)
145		goto out;
146
147	if (rw_lock) {
148		ni_lock(mft_ni);
149		down_write(rw_lock);
150	}
151	err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run,
152				 vbo >> sbi->cluster_bits);
153	if (rw_lock) {
154		up_write(rw_lock);
155		ni_unlock(mft_ni);
156	}
157	if (err)
158		goto out;
159
160	if (rw_lock)
161		down_read(rw_lock);
162	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
163	if (rw_lock)
164		up_read(rw_lock);
165
166	if (err == -E_NTFS_FIXUP) {
167		mi->dirty = true;
168		goto ok;
169	}
170	if (err)
171		goto out;
172
173ok:
174	/* Check field 'total' only here. */
175	if (le32_to_cpu(rec->total) != bpr) {
176		err = -EINVAL;
177		goto out;
178	}
179
180	return 0;
181
182out:
183	if (err == -E_NTFS_CORRUPT) {
184		ntfs_err(sbi->sb, "mft corrupted");
185		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
186		err = -EINVAL;
187	}
188
189	return err;
190}
191
192/*
193 * mi_enum_attr - start/continue attributes enumeration in record.
194 *
195 * NOTE: mi->mrec - memory of size sbi->record_size
196 * here we sure that mi->mrec->total == sbi->record_size (see mi_read)
197 */
198struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
199{
200	const struct MFT_REC *rec = mi->mrec;
201	u32 used = le32_to_cpu(rec->used);
202	u32 t32, off, asize, prev_type;
203	u16 t16;
204	u64 data_size, alloc_size, tot_size;
205
206	if (!attr) {
207		u32 total = le32_to_cpu(rec->total);
208
209		off = le16_to_cpu(rec->attr_off);
210
211		if (used > total)
212			return NULL;
213
214		if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
215		    !IS_ALIGNED(off, 4)) {
216			return NULL;
217		}
218
219		/* Skip non-resident records. */
220		if (!is_rec_inuse(rec))
221			return NULL;
222
223		prev_type = 0;
224		attr = Add2Ptr(rec, off);
225	} else {
226		/* Check if input attr inside record. */
227		off = PtrOffset(rec, attr);
228		if (off >= used)
229			return NULL;
230
231		asize = le32_to_cpu(attr->size);
232		if (asize < SIZEOF_RESIDENT) {
233			/* Impossible 'cause we should not return such attribute. */
234			return NULL;
235		}
236
237		/* Overflow check. */
238		if (off + asize < off)
239			return NULL;
240
241		prev_type = le32_to_cpu(attr->type);
242		attr = Add2Ptr(attr, asize);
243		off += asize;
244	}
245
246	asize = le32_to_cpu(attr->size);
247
248	/* Can we use the first field (attr->type). */
249	if (off + 8 > used) {
250		static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
251		return NULL;
252	}
253
254	if (attr->type == ATTR_END) {
255		/* End of enumeration. */
256		return NULL;
257	}
258
259	/* 0x100 is last known attribute for now. */
260	t32 = le32_to_cpu(attr->type);
261	if (!t32 || (t32 & 0xf) || (t32 > 0x100))
262		return NULL;
263
264	/* attributes in record must be ordered by type */
265	if (t32 < prev_type)
266		return NULL;
267
268	/* Check overflow and boundary. */
269	if (off + asize < off || off + asize > used)
270		return NULL;
271
272	/* Check size of attribute. */
273	if (!attr->non_res) {
274		/* Check resident fields. */
275		if (asize < SIZEOF_RESIDENT)
276			return NULL;
277
278		t16 = le16_to_cpu(attr->res.data_off);
279		if (t16 > asize)
280			return NULL;
281
282		if (le32_to_cpu(attr->res.data_size) > asize - t16)
283			return NULL;
284
285		t32 = sizeof(short) * attr->name_len;
286		if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
287			return NULL;
288
289		return attr;
290	}
291
292	/* Check nonresident fields. */
293	if (attr->non_res != 1)
294		return NULL;
295
296	t16 = le16_to_cpu(attr->nres.run_off);
297	if (t16 > asize)
298		return NULL;
299
300	t32 = sizeof(short) * attr->name_len;
301	if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
302		return NULL;
303
304	/* Check start/end vcn. */
305	if (le64_to_cpu(attr->nres.svcn) > le64_to_cpu(attr->nres.evcn) + 1)
306		return NULL;
307
308	data_size = le64_to_cpu(attr->nres.data_size);
309	if (le64_to_cpu(attr->nres.valid_size) > data_size)
310		return NULL;
311
312	alloc_size = le64_to_cpu(attr->nres.alloc_size);
313	if (data_size > alloc_size)
314		return NULL;
315
316	t32 = mi->sbi->cluster_mask;
317	if (alloc_size & t32)
318		return NULL;
319
320	if (!attr->nres.svcn && is_attr_ext(attr)) {
321		/* First segment of sparse/compressed attribute */
322		if (asize + 8 < SIZEOF_NONRESIDENT_EX)
323			return NULL;
324
325		tot_size = le64_to_cpu(attr->nres.total_size);
326		if (tot_size & t32)
327			return NULL;
328
329		if (tot_size > alloc_size)
330			return NULL;
331	} else {
332		if (asize + 8 < SIZEOF_NONRESIDENT)
333			return NULL;
334
335		if (attr->nres.c_unit)
336			return NULL;
337	}
338
339	return attr;
340}
341
342/*
343 * mi_find_attr - Find the attribute by type and name and id.
344 */
345struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
346			    enum ATTR_TYPE type, const __le16 *name,
347			    u8 name_len, const __le16 *id)
348{
349	u32 type_in = le32_to_cpu(type);
350	u32 atype;
351
352next_attr:
353	attr = mi_enum_attr(mi, attr);
354	if (!attr)
355		return NULL;
356
357	atype = le32_to_cpu(attr->type);
358	if (atype > type_in)
359		return NULL;
360
361	if (atype < type_in)
362		goto next_attr;
363
364	if (attr->name_len != name_len)
365		goto next_attr;
366
367	if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
368		goto next_attr;
369
370	if (id && *id != attr->id)
371		goto next_attr;
372
373	return attr;
374}
375
376int mi_write(struct mft_inode *mi, int wait)
377{
378	struct MFT_REC *rec;
379	int err;
380	struct ntfs_sb_info *sbi;
381
382	if (!mi->dirty)
383		return 0;
384
385	sbi = mi->sbi;
386	rec = mi->mrec;
387
388	err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
389	if (err)
390		return err;
391
392	if (mi->rno < sbi->mft.recs_mirr)
393		sbi->flags |= NTFS_FLAGS_MFTMIRR;
394
395	mi->dirty = false;
396
397	return 0;
398}
399
400int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
401		  __le16 flags, bool is_mft)
402{
403	int err;
404	u16 seq = 1;
405	struct MFT_REC *rec;
406	u64 vbo = (u64)rno << sbi->record_bits;
407
408	err = mi_init(mi, sbi, rno);
409	if (err)
410		return err;
411
412	rec = mi->mrec;
413
414	if (rno == MFT_REC_MFT) {
415		;
416	} else if (rno < MFT_REC_FREE) {
417		seq = rno;
418	} else if (rno >= sbi->mft.used) {
419		;
420	} else if (mi_read(mi, is_mft)) {
421		;
422	} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
423		/* Record is reused. Update its sequence number. */
424		seq = le16_to_cpu(rec->seq) + 1;
425		if (!seq)
426			seq = 1;
427	}
428
429	memcpy(rec, sbi->new_rec, sbi->record_size);
430
431	rec->seq = cpu_to_le16(seq);
432	rec->flags = RECORD_FLAG_IN_USE | flags;
433	if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3)
434		rec->mft_record = cpu_to_le32(rno);
435
436	mi->dirty = true;
437
438	if (!mi->nb.nbufs) {
439		struct ntfs_inode *ni = sbi->mft.ni;
440		bool lock = false;
441
442		if (is_mounted(sbi) && !is_mft) {
443			down_read(&ni->file.run_lock);
444			lock = true;
445		}
446
447		err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
448				  &mi->nb);
449		if (lock)
450			up_read(&ni->file.run_lock);
451	}
452
453	return err;
454}
455
456/*
457 * mi_insert_attr - Reserve space for new attribute.
458 *
459 * Return: Not full constructed attribute or NULL if not possible to create.
460 */
461struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
462			      const __le16 *name, u8 name_len, u32 asize,
463			      u16 name_off)
464{
465	size_t tail;
466	struct ATTRIB *attr;
467	__le16 id;
468	struct MFT_REC *rec = mi->mrec;
469	struct ntfs_sb_info *sbi = mi->sbi;
470	u32 used = le32_to_cpu(rec->used);
471	const u16 *upcase = sbi->upcase;
472
473	/* Can we insert mi attribute? */
474	if (used + asize > sbi->record_size)
475		return NULL;
476
477	/*
478	 * Scan through the list of attributes to find the point
479	 * at which we should insert it.
480	 */
481	attr = NULL;
482	while ((attr = mi_enum_attr(mi, attr))) {
483		int diff = compare_attr(attr, type, name, name_len, upcase);
484
485		if (diff < 0)
486			continue;
487
488		if (!diff && !is_attr_indexed(attr))
489			return NULL;
490		break;
491	}
492
493	if (!attr) {
494		/* Append. */
495		tail = 8;
496		attr = Add2Ptr(rec, used - 8);
497	} else {
498		/* Insert before 'attr'. */
499		tail = used - PtrOffset(rec, attr);
500	}
501
502	id = mi_new_attt_id(mi);
503
504	memmove(Add2Ptr(attr, asize), attr, tail);
505	memset(attr, 0, asize);
506
507	attr->type = type;
508	attr->size = cpu_to_le32(asize);
509	attr->name_len = name_len;
510	attr->name_off = cpu_to_le16(name_off);
511	attr->id = id;
512
513	memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
514	rec->used = cpu_to_le32(used + asize);
515
516	mi->dirty = true;
517
518	return attr;
519}
520
521/*
522 * mi_remove_attr - Remove the attribute from record.
523 *
524 * NOTE: The source attr will point to next attribute.
525 */
526bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
527		    struct ATTRIB *attr)
528{
529	struct MFT_REC *rec = mi->mrec;
530	u32 aoff = PtrOffset(rec, attr);
531	u32 used = le32_to_cpu(rec->used);
532	u32 asize = le32_to_cpu(attr->size);
533
534	if (aoff + asize > used)
535		return false;
536
537	if (ni && is_attr_indexed(attr)) {
538		u16 links = le16_to_cpu(ni->mi.mrec->hard_links);
539		struct ATTR_FILE_NAME *fname =
540			attr->type != ATTR_NAME ?
541				NULL :
542				resident_data_ex(attr,
543						 SIZEOF_ATTRIBUTE_FILENAME);
544		if (fname && fname->type == FILE_NAME_DOS) {
545			/* Do not decrease links count deleting DOS name. */
546		} else if (!links) {
547			/* minor error. Not critical. */
548		} else {
549			ni->mi.mrec->hard_links = cpu_to_le16(links - 1);
550			ni->mi.dirty = true;
551		}
552	}
553
554	used -= asize;
555	memmove(attr, Add2Ptr(attr, asize), used - aoff);
556	rec->used = cpu_to_le32(used);
557	mi->dirty = true;
558
559	return true;
560}
561
562/* bytes = "new attribute size" - "old attribute size" */
563bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
564{
565	struct MFT_REC *rec = mi->mrec;
566	u32 aoff = PtrOffset(rec, attr);
567	u32 total, used = le32_to_cpu(rec->used);
568	u32 nsize, asize = le32_to_cpu(attr->size);
569	u32 rsize = le32_to_cpu(attr->res.data_size);
570	int tail = (int)(used - aoff - asize);
571	int dsize;
572	char *next;
573
574	if (tail < 0 || aoff >= used)
575		return false;
576
577	if (!bytes)
578		return true;
579
580	total = le32_to_cpu(rec->total);
581	next = Add2Ptr(attr, asize);
582
583	if (bytes > 0) {
584		dsize = ALIGN(bytes, 8);
585		if (used + dsize > total)
586			return false;
587		nsize = asize + dsize;
588		/* Move tail */
589		memmove(next + dsize, next, tail);
590		memset(next, 0, dsize);
591		used += dsize;
592		rsize += dsize;
593	} else {
594		dsize = ALIGN(-bytes, 8);
595		if (dsize > asize)
596			return false;
597		nsize = asize - dsize;
598		memmove(next - dsize, next, tail);
599		used -= dsize;
600		rsize -= dsize;
601	}
602
603	rec->used = cpu_to_le32(used);
604	attr->size = cpu_to_le32(nsize);
605	if (!attr->non_res)
606		attr->res.data_size = cpu_to_le32(rsize);
607	mi->dirty = true;
608
609	return true;
610}
611
612/*
613 * Pack runs in MFT record.
614 * If failed record is not changed.
615 */
616int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
617		 struct runs_tree *run, CLST len)
618{
619	int err = 0;
620	struct ntfs_sb_info *sbi = mi->sbi;
621	u32 new_run_size;
622	CLST plen;
623	struct MFT_REC *rec = mi->mrec;
624	CLST svcn = le64_to_cpu(attr->nres.svcn);
625	u32 used = le32_to_cpu(rec->used);
626	u32 aoff = PtrOffset(rec, attr);
627	u32 asize = le32_to_cpu(attr->size);
628	char *next = Add2Ptr(attr, asize);
629	u16 run_off = le16_to_cpu(attr->nres.run_off);
630	u32 run_size = asize - run_off;
631	u32 tail = used - aoff - asize;
632	u32 dsize = sbi->record_size - used;
633
634	/* Make a maximum gap in current record. */
635	memmove(next + dsize, next, tail);
636
637	/* Pack as much as possible. */
638	err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
639		       &plen);
640	if (err < 0) {
641		memmove(next, next + dsize, tail);
642		return err;
643	}
644
645	new_run_size = ALIGN(err, 8);
646
647	memmove(next + new_run_size - run_size, next + dsize, tail);
648
649	attr->size = cpu_to_le32(asize + new_run_size - run_size);
650	attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
651	rec->used = cpu_to_le32(used + new_run_size - run_size);
652	mi->dirty = true;
653
654	return 0;
655}