summaryrefslogtreecommitdiff
path: root/fs/ubifs/ubifs.c
blob: 4465523d5fbe49ef9beb693ae909e7cdd86fdaa0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 *
 * (C) Copyright 2008-2010
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * Authors: Artem Bityutskiy (Битюцкий Артём)
 *          Adrian Hunter
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include <common.h>
#include <memalign.h>
#include "ubifs.h"
#include <u-boot/zlib.h>

#include <linux/err.h>
#include <linux/lzo.h>

DECLARE_GLOBAL_DATA_PTR;

/* compress.c */

/*
 * We need a wrapper for zunzip() because the parameters are
 * incompatible with the lzo decompressor.
 */
static int gzip_decompress(const unsigned char *in, size_t in_len,
			   unsigned char *out, size_t *out_len)
{
	return zunzip(out, *out_len, (unsigned char *)in,
		      (unsigned long *)out_len, 0, 0);
}

/* Fake description object for the "none" compressor */
static struct ubifs_compressor none_compr = {
	.compr_type = UBIFS_COMPR_NONE,
	.name = "none",
	.capi_name = "",
	.decompress = NULL,
};

static struct ubifs_compressor lzo_compr = {
	.compr_type = UBIFS_COMPR_LZO,
#ifndef __UBOOT__
	.comp_mutex = &lzo_mutex,
#endif
	.name = "lzo",
	.capi_name = "lzo",
	.decompress = lzo1x_decompress_safe,
};

static struct ubifs_compressor zlib_compr = {
	.compr_type = UBIFS_COMPR_ZLIB,
#ifndef __UBOOT__
	.comp_mutex = &deflate_mutex,
	.decomp_mutex = &inflate_mutex,
#endif
	.name = "zlib",
	.capi_name = "deflate",
	.decompress = gzip_decompress,
};

/* All UBIFS compressors */
struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];


#ifdef __UBOOT__
/* from mm/util.c */

/**
 * kmemdup - duplicate region of memory
 *
 * @src: memory region to duplicate
 * @len: memory region length
 * @gfp: GFP mask to use
 */
void *kmemdup(const void *src, size_t len, gfp_t gfp)
{
	void *p;

	p = kmalloc(len, gfp);
	if (p)
		memcpy(p, src, len);
	return p;
}

struct crypto_comp {
	int compressor;
};

static inline struct crypto_comp
*crypto_alloc_comp(const char *alg_name, u32 type, u32 mask)
{
	struct ubifs_compressor *comp;
	struct crypto_comp *ptr;
	int i = 0;

	ptr = malloc_cache_aligned(sizeof(struct crypto_comp));
	while (i < UBIFS_COMPR_TYPES_CNT) {
		comp = ubifs_compressors[i];
		if (!comp) {
			i++;
			continue;
		}
		if (strncmp(alg_name, comp->capi_name, strlen(alg_name)) == 0) {
			ptr->compressor = i;
			return ptr;
		}
		i++;
	}
	if (i >= UBIFS_COMPR_TYPES_CNT) {
		dbg_gen("invalid compression type %s", alg_name);
		free (ptr);
		return NULL;
	}
	return ptr;
}
static inline int
crypto_comp_decompress(const struct ubifs_info *c, struct crypto_comp *tfm,
		       const u8 *src, unsigned int slen, u8 *dst,
		       unsigned int *dlen)
{
	struct ubifs_compressor *compr = ubifs_compressors[tfm->compressor];
	int err;

	if (compr->compr_type == UBIFS_COMPR_NONE) {
		memcpy(dst, src, slen);
		*dlen = slen;
		return 0;
	}

	err = compr->decompress(src, slen, dst, (size_t *)dlen);
	if (err)
		ubifs_err(c, "cannot decompress %d bytes, compressor %s, "
			  "error %d", slen, compr->name, err);

	return err;

	return 0;
}

/* from shrinker.c */

/* Global clean znode counter (for all mounted UBIFS instances) */
atomic_long_t ubifs_clean_zn_cnt;

#endif

/**
 * ubifs_decompress - decompress data.
 * @in_buf: data to decompress
 * @in_len: length of the data to decompress
 * @out_buf: output buffer where decompressed data should
 * @out_len: output length is returned here
 * @compr_type: type of compression
 *
 * This function decompresses data from buffer @in_buf into buffer @out_buf.
 * The length of the uncompressed data is returned in @out_len. This functions
 * returns %0 on success or a negative error code on failure.
 */
int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,
		     int in_len, void *out_buf, int *out_len, int compr_type)
{
	int err;
	struct ubifs_compressor *compr;

	if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
		ubifs_err(c, "invalid compression type %d", compr_type);
		return -EINVAL;
	}

	compr = ubifs_compressors[compr_type];

	if (unlikely(!compr->capi_name)) {
		ubifs_err(c, "%s compression is not compiled in", compr->name);
		return -EINVAL;
	}

	if (compr_type == UBIFS_COMPR_NONE) {
		memcpy(out_buf, in_buf, in_len);
		*out_len = in_len;
		return 0;
	}

	if (compr->decomp_mutex)
		mutex_lock(compr->decomp_mutex);
	err = crypto_comp_decompress(c, compr->cc, in_buf, in_len, out_buf,
				     (unsigned int *)out_len);
	if (compr->decomp_mutex)
		mutex_unlock(compr->decomp_mutex);
	if (err)
		ubifs_err(c, "cannot decompress %d bytes, compressor %s,"
			  " error %d", in_len, compr->name, err);

	return err;
}

/**
 * compr_init - initialize a compressor.
 * @compr: compressor description object
 *
 * This function initializes the requested compressor and returns zero in case
 * of success or a negative error code in case of failure.
 */
static int __init compr_init(struct ubifs_compressor *compr)
{
	ubifs_compressors[compr->compr_type] = compr;

#ifdef CONFIG_NEEDS_MANUAL_RELOC
	ubifs_compressors[compr->compr_type]->name += gd->reloc_off;
	ubifs_compressors[compr->compr_type]->capi_name += gd->reloc_off;
	ubifs_compressors[compr->compr_type]->decompress += gd->reloc_off;
#endif

	if (compr->capi_name) {
		compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
		if (IS_ERR(compr->cc)) {
			dbg_gen("cannot initialize compressor %s,"
				  " error %ld", compr->name,
				  PTR_ERR(compr->cc));
			return PTR_ERR(compr->cc);
		}
	}

	return 0;
}

/**
 * ubifs_compressors_init - initialize UBIFS compressors.
 *
 * This function initializes the compressor which were compiled in. Returns
 * zero in case of success and a negative error code in case of failure.
 */
int __init ubifs_compressors_init(void)
{
	int err;

	err = compr_init(&lzo_compr);
	if (err)
		return err;

	err = compr_init(&zlib_compr);
	if (err)
		return err;

	err = compr_init(&none_compr);
	if (err)
		return err;

	return 0;
}

/*
 * ubifsls...
 */

static int filldir(struct ubifs_info *c, const char *name, int namlen,
		   u64 ino, unsigned int d_type)
{
	struct inode *inode;
	char filetime[32];

	switch (d_type) {
	case UBIFS_ITYPE_REG:
		printf("\t");
		break;
	case UBIFS_ITYPE_DIR:
		printf("<DIR>\t");
		break;
	case UBIFS_ITYPE_LNK:
		printf("<LNK>\t");
		break;
	default:
		printf("other\t");
		break;
	}

	inode = ubifs_iget(c->vfs_sb, ino);
	if (IS_ERR(inode)) {
		printf("%s: Error in ubifs_iget(), ino=%lld ret=%p!\n",
		       __func__, ino, inode);
		return -1;
	}
	ctime_r((time_t *)&inode->i_mtime, filetime);
	printf("%9lld  %24.24s  ", inode->i_size, filetime);
#ifndef __UBOOT__
	ubifs_iput(inode);
#endif

	printf("%s\n", name);

	return 0;
}

static int ubifs_printdir(struct file *file, void *dirent)
{
	int err, over = 0;
	struct qstr nm;
	union ubifs_key key;
	struct ubifs_dent_node *dent;
	struct inode *dir = file->f_path.dentry->d_inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;

	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);

	if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
		/*
		 * The directory was seek'ed to a senseless position or there
		 * are no more entries.
		 */
		return 0;

	if (file->f_pos == 1) {
		/* Find the first entry in TNC and save it */
		lowest_dent_key(c, &key, dir->i_ino);
		nm.name = NULL;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		file->f_pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	dent = file->private_data;
	if (!dent) {
		/*
		 * The directory was seek'ed to and is now readdir'ed.
		 * Find the entry corresponding to @file->f_pos or the
		 * closest one.
		 */
		dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
		nm.name = NULL;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}
		file->f_pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	while (1) {
		dbg_gen("feed '%s', ino %llu, new f_pos %#x",
			dent->name, (unsigned long long)le64_to_cpu(dent->inum),
			key_hash_flash(c, &dent->key));
		ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);

		nm.len = le16_to_cpu(dent->nlen);
		over = filldir(c, (char *)dent->name, nm.len,
			       le64_to_cpu(dent->inum), dent->type);
		if (over)
			return 0;

		/* Switch to the next entry */
		key_read(c, &dent->key, &key);
		nm.name = (char *)dent->name;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		kfree(file->private_data);
		file->f_pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
		cond_resched();
	}

out:
	if (err != -ENOENT) {
		ubifs_err(c, "cannot find next direntry, error %d", err);
		return err;
	}

	kfree(file->private_data);
	file->private_data = NULL;
	file->f_pos = 2;
	return 0;
}

static int ubifs_finddir(struct super_block *sb, char *dirname,
			 unsigned long root_inum, unsigned long *inum)
{
	int err;
	struct qstr nm;
	union ubifs_key key;
	struct ubifs_dent_node *dent;
	struct ubifs_info *c;
	struct file *file;
	struct dentry *dentry;
	struct inode *dir;
	int ret = 0;

	file = kzalloc(sizeof(struct file), 0);
	dentry = kzalloc(sizeof(struct dentry), 0);
	dir = kzalloc(sizeof(struct inode), 0);
	if (!file || !dentry || !dir) {
		printf("%s: Error, no memory for malloc!\n", __func__);
		err = -ENOMEM;
		goto out;
	}

	dir->i_sb = sb;
	file->f_path.dentry = dentry;
	file->f_path.dentry->d_parent = dentry;
	file->f_path.dentry->d_inode = dir;
	file->f_path.dentry->d_inode->i_ino = root_inum;
	c = sb->s_fs_info;

	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);

	/* Find the first entry in TNC and save it */
	lowest_dent_key(c, &key, dir->i_ino);
	nm.name = NULL;
	dent = ubifs_tnc_next_ent(c, &key, &nm);
	if (IS_ERR(dent)) {
		err = PTR_ERR(dent);
		goto out;
	}

	file->f_pos = key_hash_flash(c, &dent->key);
	file->private_data = dent;

	while (1) {
		dbg_gen("feed '%s', ino %llu, new f_pos %#x",
			dent->name, (unsigned long long)le64_to_cpu(dent->inum),
			key_hash_flash(c, &dent->key));
		ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);

		nm.len = le16_to_cpu(dent->nlen);
		if ((strncmp(dirname, (char *)dent->name, nm.len) == 0) &&
		    (strlen(dirname) == nm.len)) {
			*inum = le64_to_cpu(dent->inum);
			ret = 1;
			goto out_free;
		}

		/* Switch to the next entry */
		key_read(c, &dent->key, &key);
		nm.name = (char *)dent->name;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		kfree(file->private_data);
		file->f_pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
		cond_resched();
	}

out:
	if (err != -ENOENT)
		dbg_gen("cannot find next direntry, error %d", err);

out_free:
	kfree(file->private_data);
	free(file);
	free(dentry);
	free(dir);

	return ret;
}

static unsigned long ubifs_findfile(struct super_block *sb, char *filename)
{
	int ret;
	char *next;
	char fpath[128];
	char symlinkpath[128];
	char *name = fpath;
	unsigned long root_inum = 1;
	unsigned long inum;
	int symlink_count = 0; /* Don't allow symlink recursion */
	char link_name[64];

	strcpy(fpath, filename);

	/* Remove all leading slashes */
	while (*name == '/')
		name++;

	/*
	 * Handle root-direcoty ('/')
	 */
	inum = root_inum;
	if (!name || *name == '\0')
		return inum;

	for (;;) {
		struct inode *inode;
		struct ubifs_inode *ui;

		/* Extract the actual part from the pathname.  */
		next = strchr(name, '/');
		if (next) {
			/* Remove all leading slashes.  */
			while (*next == '/')
				*(next++) = '\0';
		}

		ret = ubifs_finddir(sb, name, root_inum, &inum);
		if (!ret)
			return 0;
		inode = ubifs_iget(sb, inum);

		if (!inode)
			return 0;
		ui = ubifs_inode(inode);

		if ((inode->i_mode & S_IFMT) == S_IFLNK) {
			char buf[128];

			/* We have some sort of symlink recursion, bail out */
			if (symlink_count++ > 8) {
				printf("Symlink recursion, aborting\n");
				return 0;
			}
			memcpy(link_name, ui->data, ui->data_len);
			link_name[ui->data_len] = '\0';

			if (link_name[0] == '/') {
				/* Absolute path, redo everything without
				 * the leading slash */
				next = name = link_name + 1;
				root_inum = 1;
				continue;
			}
			/* Relative to cur dir */
			sprintf(buf, "%s/%s",
					link_name, next == NULL ? "" : next);
			memcpy(symlinkpath, buf, sizeof(buf));
			next = name = symlinkpath;
			continue;
		}

		/*
		 * Check if directory with this name exists
		 */

		/* Found the node!  */
		if (!next || *next == '\0')
			return inum;

		root_inum = inum;
		name = next;
	}

	return 0;
}

int ubifs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
{
	if (rbdd) {
		debug("UBIFS cannot be used with normal block devices\n");
		return -1;
	}

	/*
	 * Should never happen since blk_get_device_part_str() already checks
	 * this, but better safe then sorry.
	 */
	if (!ubifs_is_mounted()) {
		debug("UBIFS not mounted, use ubifsmount to mount volume first!\n");
		return -1;
	}

	return 0;
}

int ubifs_ls(const char *filename)
{
	struct ubifs_info *c = ubifs_sb->s_fs_info;
	struct file *file;
	struct dentry *dentry;
	struct inode *dir;
	void *dirent = NULL;
	unsigned long inum;
	int ret = 0;

	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
	inum = ubifs_findfile(ubifs_sb, (char *)filename);
	if (!inum) {
		ret = -1;
		goto out;
	}

	file = kzalloc(sizeof(struct file), 0);
	dentry = kzalloc(sizeof(struct dentry), 0);
	dir = kzalloc(sizeof(struct inode), 0);
	if (!file || !dentry || !dir) {
		printf("%s: Error, no memory for malloc!\n", __func__);
		ret = -ENOMEM;
		goto out_mem;
	}

	dir->i_sb = ubifs_sb;
	file->f_path.dentry = dentry;
	file->f_path.dentry->d_parent = dentry;
	file->f_path.dentry->d_inode = dir;
	file->f_path.dentry->d_inode->i_ino = inum;
	file->f_pos = 1;
	file->private_data = NULL;
	ubifs_printdir(file, dirent);

out_mem:
	if (file)
		free(file);
	if (dentry)
		free(dentry);
	if (dir)
		free(dir);

out:
	ubi_close_volume(c->ubi);
	return ret;
}

int ubifs_exists(const char *filename)
{
	struct ubifs_info *c = ubifs_sb->s_fs_info;
	unsigned long inum;

	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
	inum = ubifs_findfile(ubifs_sb, (char *)filename);
	ubi_close_volume(c->ubi);

	return inum != 0;
}

int ubifs_size(const char *filename, loff_t *size)
{
	struct ubifs_info *c = ubifs_sb->s_fs_info;
	unsigned long inum;
	struct inode *inode;
	int err = 0;

	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);

	inum = ubifs_findfile(ubifs_sb, (char *)filename);
	if (!inum) {
		err = -1;
		goto out;
	}

	inode = ubifs_iget(ubifs_sb, inum);
	if (IS_ERR(inode)) {
		printf("%s: Error reading inode %ld!\n", __func__, inum);
		err = PTR_ERR(inode);
		goto out;
	}

	*size = inode->i_size;

	ubifs_iput(inode);
out:
	ubi_close_volume(c->ubi);
	return err;
}

/*
 * ubifsload...
 */

/* file.c */

static inline void *kmap(struct page *page)
{
	return page->addr;
}

static int read_block(struct inode *inode, void *addr, unsigned int block,
		      struct ubifs_data_node *dn)
{
	struct ubifs_info *c = inode->i_sb->s_fs_info;
	int err, len, out_len;
	union ubifs_key key;
	unsigned int dlen;

	data_key_init(c, &key, inode->i_ino, block);
	err = ubifs_tnc_lookup(c, &key, dn);
	if (err) {
		if (err == -ENOENT)
			/* Not found, so it must be a hole */
			memset(addr, 0, UBIFS_BLOCK_SIZE);
		return err;
	}

	ubifs_assert(le64_to_cpu(dn->ch.sqnum) > ubifs_inode(inode)->creat_sqnum);

	len = le32_to_cpu(dn->size);
	if (len <= 0 || len > UBIFS_BLOCK_SIZE)
		goto dump;

	dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
	out_len = UBIFS_BLOCK_SIZE;
	err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
			       le16_to_cpu(dn->compr_type));
	if (err || len != out_len)
		goto dump;

	/*
	 * Data length can be less than a full block, even for blocks that are
	 * not the last in the file (e.g., as a result of making a hole and
	 * appending data). Ensure that the remainder is zeroed out.
	 */
	if (len < UBIFS_BLOCK_SIZE)
		memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);

	return 0;

dump:
	ubifs_err(c, "bad data node (block %u, inode %lu)",
		  block, inode->i_ino);
	ubifs_dump_node(c, dn);
	return -EINVAL;
}

static int do_readpage(struct ubifs_info *c, struct inode *inode,
		       struct page *page, int last_block_size)
{
	void *addr;
	int err = 0, i;
	unsigned int block, beyond;
	struct ubifs_data_node *dn;
	loff_t i_size = inode->i_size;

	dbg_gen("ino %lu, pg %lu, i_size %lld",
		inode->i_ino, page->index, i_size);

	addr = kmap(page);

	block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
	beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
	if (block >= beyond) {
		/* Reading beyond inode */
		memset(addr, 0, PAGE_CACHE_SIZE);
		goto out;
	}

	dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
	if (!dn)
		return -ENOMEM;

	i = 0;
	while (1) {
		int ret;

		if (block >= beyond) {
			/* Reading beyond inode */
			err = -ENOENT;
			memset(addr, 0, UBIFS_BLOCK_SIZE);
		} else {
			/*
			 * Reading last block? Make sure to not write beyond
			 * the requested size in the destination buffer.
			 */
			if (((block + 1) == beyond) || last_block_size) {
				void *buff;
				int dlen;

				/*
				 * We need to buffer the data locally for the
				 * last block. This is to not pad the
				 * destination area to a multiple of
				 * UBIFS_BLOCK_SIZE.
				 */
				buff = malloc_cache_aligned(UBIFS_BLOCK_SIZE);
				if (!buff) {
					printf("%s: Error, malloc fails!\n",
					       __func__);
					err = -ENOMEM;
					break;
				}

				/* Read block-size into temp buffer */
				ret = read_block(inode, buff, block, dn);
				if (ret) {
					err = ret;
					if (err != -ENOENT) {
						free(buff);
						break;
					}
				}

				if (last_block_size)
					dlen = last_block_size;
				else
					dlen = le32_to_cpu(dn->size);

				/* Now copy required size back to dest */
				memcpy(addr, buff, dlen);

				free(buff);
			} else {
				ret = read_block(inode, addr, block, dn);
				if (ret) {
					err = ret;
					if (err != -ENOENT)
						break;
				}
			}
		}
		if (++i >= UBIFS_BLOCKS_PER_PAGE)
			break;
		block += 1;
		addr += UBIFS_BLOCK_SIZE;
	}
	if (err) {
		if (err == -ENOENT) {
			/* Not found, so it must be a hole */
			dbg_gen("hole");
			goto out_free;
		}
		ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
			  page->index, inode->i_ino, err);
		goto error;
	}

out_free:
	kfree(dn);
out:
	return 0;

error:
	kfree(dn);
	return err;
}

int ubifs_read(const char *filename, void *buf, loff_t offset,
	       loff_t size, loff_t *actread)
{
	struct ubifs_info *c = ubifs_sb->s_fs_info;
	unsigned long inum;
	struct inode *inode;
	struct page page;
	int err = 0;
	int i;
	int count;
	int last_block_size = 0;

	*actread = 0;

	if (offset & (PAGE_SIZE - 1)) {
		printf("ubifs: Error offset must be a multiple of %d\n",
		       PAGE_SIZE);
		return -1;
	}

	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
	/* ubifs_findfile will resolve symlinks, so we know that we get
	 * the real file here */
	inum = ubifs_findfile(ubifs_sb, (char *)filename);
	if (!inum) {
		err = -1;
		goto out;
	}

	/*
	 * Read file inode
	 */
	inode = ubifs_iget(ubifs_sb, inum);
	if (IS_ERR(inode)) {
		printf("%s: Error reading inode %ld!\n", __func__, inum);
		err = PTR_ERR(inode);
		goto out;
	}

	if (offset > inode->i_size) {
		printf("ubifs: Error offset (%lld) > file-size (%lld)\n",
		       offset, size);
		err = -1;
		goto put_inode;
	}

	/*
	 * If no size was specified or if size bigger than filesize
	 * set size to filesize
	 */
	if ((size == 0) || (size > (inode->i_size - offset)))
		size = inode->i_size - offset;

	count = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;

	page.addr = buf;
	page.index = offset / PAGE_SIZE;
	page.inode = inode;
	for (i = 0; i < count; i++) {
		/*
		 * Make sure to not read beyond the requested size
		 */
		if (((i + 1) == count) && (size < inode->i_size))
			last_block_size = size - (i * PAGE_SIZE);

		err = do_readpage(c, inode, &page, last_block_size);
		if (err)
			break;

		page.addr += PAGE_SIZE;
		page.index++;
	}

	if (err) {
		printf("Error reading file '%s'\n", filename);
		*actread = i * PAGE_SIZE;
	} else {
		*actread = size;
	}

put_inode:
	ubifs_iput(inode);

out:
	ubi_close_volume(c->ubi);
	return err;
}

void ubifs_close(void)
{
}

/* Compat wrappers for common/cmd_ubifs.c */
int ubifs_load(char *filename, u32 addr, u32 size)
{
	loff_t actread;
	int err;

	printf("Loading file '%s' to addr 0x%08x...\n", filename, addr);

	err = ubifs_read(filename, (void *)(uintptr_t)addr, 0, size, &actread);
	if (err == 0) {
		env_set_hex("filesize", actread);
		printf("Done\n");
	}

	return err;
}

void uboot_ubifs_umount(void)
{
	if (ubifs_sb) {
		printf("Unmounting UBIFS volume %s!\n",
		       ((struct ubifs_info *)(ubifs_sb->s_fs_info))->vi.name);
		ubifs_umount(ubifs_sb->s_fs_info);
		ubifs_sb = NULL;
	}
}