xref: /openbmc/u-boot/fs/ubifs/ubifs.c (revision a187559e)
1 /*
2  * This file is part of UBIFS.
3  *
4  * Copyright (C) 2006-2008 Nokia Corporation.
5  *
6  * (C) Copyright 2008-2010
7  * Stefan Roese, DENX Software Engineering, sr@denx.de.
8  *
9  * Authors: Artem Bityutskiy (Битюцкий Артём)
10  *          Adrian Hunter
11  *
12  * SPDX-License-Identifier:	GPL-2.0
13  */
14 
15 #include <common.h>
16 #include <memalign.h>
17 #include "ubifs.h"
18 #include <u-boot/zlib.h>
19 
20 #include <linux/err.h>
21 #include <linux/lzo.h>
22 
23 DECLARE_GLOBAL_DATA_PTR;
24 
25 /* compress.c */
26 
27 /*
28  * We need a wrapper for zunzip() because the parameters are
29  * incompatible with the lzo decompressor.
30  */
31 static int gzip_decompress(const unsigned char *in, size_t in_len,
32 			   unsigned char *out, size_t *out_len)
33 {
34 	return zunzip(out, *out_len, (unsigned char *)in,
35 		      (unsigned long *)out_len, 0, 0);
36 }
37 
38 /* Fake description object for the "none" compressor */
39 static struct ubifs_compressor none_compr = {
40 	.compr_type = UBIFS_COMPR_NONE,
41 	.name = "none",
42 	.capi_name = "",
43 	.decompress = NULL,
44 };
45 
46 static struct ubifs_compressor lzo_compr = {
47 	.compr_type = UBIFS_COMPR_LZO,
48 #ifndef __UBOOT__
49 	.comp_mutex = &lzo_mutex,
50 #endif
51 	.name = "lzo",
52 	.capi_name = "lzo",
53 	.decompress = lzo1x_decompress_safe,
54 };
55 
56 static struct ubifs_compressor zlib_compr = {
57 	.compr_type = UBIFS_COMPR_ZLIB,
58 #ifndef __UBOOT__
59 	.comp_mutex = &deflate_mutex,
60 	.decomp_mutex = &inflate_mutex,
61 #endif
62 	.name = "zlib",
63 	.capi_name = "deflate",
64 	.decompress = gzip_decompress,
65 };
66 
67 /* All UBIFS compressors */
68 struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
69 
70 
71 #ifdef __UBOOT__
72 /* from mm/util.c */
73 
74 /**
75  * kmemdup - duplicate region of memory
76  *
77  * @src: memory region to duplicate
78  * @len: memory region length
79  * @gfp: GFP mask to use
80  */
81 void *kmemdup(const void *src, size_t len, gfp_t gfp)
82 {
83 	void *p;
84 
85 	p = kmalloc(len, gfp);
86 	if (p)
87 		memcpy(p, src, len);
88 	return p;
89 }
90 
91 struct crypto_comp {
92 	int compressor;
93 };
94 
95 static inline struct crypto_comp
96 *crypto_alloc_comp(const char *alg_name, u32 type, u32 mask)
97 {
98 	struct ubifs_compressor *comp;
99 	struct crypto_comp *ptr;
100 	int i = 0;
101 
102 	ptr = malloc_cache_aligned(sizeof(struct crypto_comp));
103 	while (i < UBIFS_COMPR_TYPES_CNT) {
104 		comp = ubifs_compressors[i];
105 		if (!comp) {
106 			i++;
107 			continue;
108 		}
109 		if (strncmp(alg_name, comp->capi_name, strlen(alg_name)) == 0) {
110 			ptr->compressor = i;
111 			return ptr;
112 		}
113 		i++;
114 	}
115 	if (i >= UBIFS_COMPR_TYPES_CNT) {
116 		dbg_gen("invalid compression type %s", alg_name);
117 		free (ptr);
118 		return NULL;
119 	}
120 	return ptr;
121 }
122 static inline int
123 crypto_comp_decompress(const struct ubifs_info *c, struct crypto_comp *tfm,
124 		       const u8 *src, unsigned int slen, u8 *dst,
125 		       unsigned int *dlen)
126 {
127 	struct ubifs_compressor *compr = ubifs_compressors[tfm->compressor];
128 	int err;
129 
130 	if (compr->compr_type == UBIFS_COMPR_NONE) {
131 		memcpy(dst, src, slen);
132 		*dlen = slen;
133 		return 0;
134 	}
135 
136 	err = compr->decompress(src, slen, dst, (size_t *)dlen);
137 	if (err)
138 		ubifs_err(c, "cannot decompress %d bytes, compressor %s, "
139 			  "error %d", slen, compr->name, err);
140 
141 	return err;
142 
143 	return 0;
144 }
145 
146 /* from shrinker.c */
147 
148 /* Global clean znode counter (for all mounted UBIFS instances) */
149 atomic_long_t ubifs_clean_zn_cnt;
150 
151 #endif
152 
153 /**
154  * ubifs_decompress - decompress data.
155  * @in_buf: data to decompress
156  * @in_len: length of the data to decompress
157  * @out_buf: output buffer where decompressed data should
158  * @out_len: output length is returned here
159  * @compr_type: type of compression
160  *
161  * This function decompresses data from buffer @in_buf into buffer @out_buf.
162  * The length of the uncompressed data is returned in @out_len. This functions
163  * returns %0 on success or a negative error code on failure.
164  */
165 int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,
166 		     int in_len, void *out_buf, int *out_len, int compr_type)
167 {
168 	int err;
169 	struct ubifs_compressor *compr;
170 
171 	if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
172 		ubifs_err(c, "invalid compression type %d", compr_type);
173 		return -EINVAL;
174 	}
175 
176 	compr = ubifs_compressors[compr_type];
177 
178 	if (unlikely(!compr->capi_name)) {
179 		ubifs_err(c, "%s compression is not compiled in", compr->name);
180 		return -EINVAL;
181 	}
182 
183 	if (compr_type == UBIFS_COMPR_NONE) {
184 		memcpy(out_buf, in_buf, in_len);
185 		*out_len = in_len;
186 		return 0;
187 	}
188 
189 	if (compr->decomp_mutex)
190 		mutex_lock(compr->decomp_mutex);
191 	err = crypto_comp_decompress(c, compr->cc, in_buf, in_len, out_buf,
192 				     (unsigned int *)out_len);
193 	if (compr->decomp_mutex)
194 		mutex_unlock(compr->decomp_mutex);
195 	if (err)
196 		ubifs_err(c, "cannot decompress %d bytes, compressor %s,"
197 			  " error %d", in_len, compr->name, err);
198 
199 	return err;
200 }
201 
202 /**
203  * compr_init - initialize a compressor.
204  * @compr: compressor description object
205  *
206  * This function initializes the requested compressor and returns zero in case
207  * of success or a negative error code in case of failure.
208  */
209 static int __init compr_init(struct ubifs_compressor *compr)
210 {
211 	ubifs_compressors[compr->compr_type] = compr;
212 
213 #ifdef CONFIG_NEEDS_MANUAL_RELOC
214 	ubifs_compressors[compr->compr_type]->name += gd->reloc_off;
215 	ubifs_compressors[compr->compr_type]->capi_name += gd->reloc_off;
216 	ubifs_compressors[compr->compr_type]->decompress += gd->reloc_off;
217 #endif
218 
219 	if (compr->capi_name) {
220 		compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
221 		if (IS_ERR(compr->cc)) {
222 			dbg_gen("cannot initialize compressor %s,"
223 				  " error %ld", compr->name,
224 				  PTR_ERR(compr->cc));
225 			return PTR_ERR(compr->cc);
226 		}
227 	}
228 
229 	return 0;
230 }
231 
232 /**
233  * ubifs_compressors_init - initialize UBIFS compressors.
234  *
235  * This function initializes the compressor which were compiled in. Returns
236  * zero in case of success and a negative error code in case of failure.
237  */
238 int __init ubifs_compressors_init(void)
239 {
240 	int err;
241 
242 	err = compr_init(&lzo_compr);
243 	if (err)
244 		return err;
245 
246 	err = compr_init(&zlib_compr);
247 	if (err)
248 		return err;
249 
250 	err = compr_init(&none_compr);
251 	if (err)
252 		return err;
253 
254 	return 0;
255 }
256 
257 /*
258  * ubifsls...
259  */
260 
261 static int filldir(struct ubifs_info *c, const char *name, int namlen,
262 		   u64 ino, unsigned int d_type)
263 {
264 	struct inode *inode;
265 	char filetime[32];
266 
267 	switch (d_type) {
268 	case UBIFS_ITYPE_REG:
269 		printf("\t");
270 		break;
271 	case UBIFS_ITYPE_DIR:
272 		printf("<DIR>\t");
273 		break;
274 	case UBIFS_ITYPE_LNK:
275 		printf("<LNK>\t");
276 		break;
277 	default:
278 		printf("other\t");
279 		break;
280 	}
281 
282 	inode = ubifs_iget(c->vfs_sb, ino);
283 	if (IS_ERR(inode)) {
284 		printf("%s: Error in ubifs_iget(), ino=%lld ret=%p!\n",
285 		       __func__, ino, inode);
286 		return -1;
287 	}
288 	ctime_r((time_t *)&inode->i_mtime, filetime);
289 	printf("%9lld  %24.24s  ", inode->i_size, filetime);
290 #ifndef __UBOOT__
291 	ubifs_iput(inode);
292 #endif
293 
294 	printf("%s\n", name);
295 
296 	return 0;
297 }
298 
299 static int ubifs_printdir(struct file *file, void *dirent)
300 {
301 	int err, over = 0;
302 	struct qstr nm;
303 	union ubifs_key key;
304 	struct ubifs_dent_node *dent;
305 	struct inode *dir = file->f_path.dentry->d_inode;
306 	struct ubifs_info *c = dir->i_sb->s_fs_info;
307 
308 	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
309 
310 	if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
311 		/*
312 		 * The directory was seek'ed to a senseless position or there
313 		 * are no more entries.
314 		 */
315 		return 0;
316 
317 	if (file->f_pos == 1) {
318 		/* Find the first entry in TNC and save it */
319 		lowest_dent_key(c, &key, dir->i_ino);
320 		nm.name = NULL;
321 		dent = ubifs_tnc_next_ent(c, &key, &nm);
322 		if (IS_ERR(dent)) {
323 			err = PTR_ERR(dent);
324 			goto out;
325 		}
326 
327 		file->f_pos = key_hash_flash(c, &dent->key);
328 		file->private_data = dent;
329 	}
330 
331 	dent = file->private_data;
332 	if (!dent) {
333 		/*
334 		 * The directory was seek'ed to and is now readdir'ed.
335 		 * Find the entry corresponding to @file->f_pos or the
336 		 * closest one.
337 		 */
338 		dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
339 		nm.name = NULL;
340 		dent = ubifs_tnc_next_ent(c, &key, &nm);
341 		if (IS_ERR(dent)) {
342 			err = PTR_ERR(dent);
343 			goto out;
344 		}
345 		file->f_pos = key_hash_flash(c, &dent->key);
346 		file->private_data = dent;
347 	}
348 
349 	while (1) {
350 		dbg_gen("feed '%s', ino %llu, new f_pos %#x",
351 			dent->name, (unsigned long long)le64_to_cpu(dent->inum),
352 			key_hash_flash(c, &dent->key));
353 		ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);
354 
355 		nm.len = le16_to_cpu(dent->nlen);
356 		over = filldir(c, (char *)dent->name, nm.len,
357 			       le64_to_cpu(dent->inum), dent->type);
358 		if (over)
359 			return 0;
360 
361 		/* Switch to the next entry */
362 		key_read(c, &dent->key, &key);
363 		nm.name = (char *)dent->name;
364 		dent = ubifs_tnc_next_ent(c, &key, &nm);
365 		if (IS_ERR(dent)) {
366 			err = PTR_ERR(dent);
367 			goto out;
368 		}
369 
370 		kfree(file->private_data);
371 		file->f_pos = key_hash_flash(c, &dent->key);
372 		file->private_data = dent;
373 		cond_resched();
374 	}
375 
376 out:
377 	if (err != -ENOENT) {
378 		ubifs_err(c, "cannot find next direntry, error %d", err);
379 		return err;
380 	}
381 
382 	kfree(file->private_data);
383 	file->private_data = NULL;
384 	file->f_pos = 2;
385 	return 0;
386 }
387 
388 static int ubifs_finddir(struct super_block *sb, char *dirname,
389 			 unsigned long root_inum, unsigned long *inum)
390 {
391 	int err;
392 	struct qstr nm;
393 	union ubifs_key key;
394 	struct ubifs_dent_node *dent;
395 	struct ubifs_info *c;
396 	struct file *file;
397 	struct dentry *dentry;
398 	struct inode *dir;
399 	int ret = 0;
400 
401 	file = kzalloc(sizeof(struct file), 0);
402 	dentry = kzalloc(sizeof(struct dentry), 0);
403 	dir = kzalloc(sizeof(struct inode), 0);
404 	if (!file || !dentry || !dir) {
405 		printf("%s: Error, no memory for malloc!\n", __func__);
406 		err = -ENOMEM;
407 		goto out;
408 	}
409 
410 	dir->i_sb = sb;
411 	file->f_path.dentry = dentry;
412 	file->f_path.dentry->d_parent = dentry;
413 	file->f_path.dentry->d_inode = dir;
414 	file->f_path.dentry->d_inode->i_ino = root_inum;
415 	c = sb->s_fs_info;
416 
417 	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
418 
419 	/* Find the first entry in TNC and save it */
420 	lowest_dent_key(c, &key, dir->i_ino);
421 	nm.name = NULL;
422 	dent = ubifs_tnc_next_ent(c, &key, &nm);
423 	if (IS_ERR(dent)) {
424 		err = PTR_ERR(dent);
425 		goto out;
426 	}
427 
428 	file->f_pos = key_hash_flash(c, &dent->key);
429 	file->private_data = dent;
430 
431 	while (1) {
432 		dbg_gen("feed '%s', ino %llu, new f_pos %#x",
433 			dent->name, (unsigned long long)le64_to_cpu(dent->inum),
434 			key_hash_flash(c, &dent->key));
435 		ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);
436 
437 		nm.len = le16_to_cpu(dent->nlen);
438 		if ((strncmp(dirname, (char *)dent->name, nm.len) == 0) &&
439 		    (strlen(dirname) == nm.len)) {
440 			*inum = le64_to_cpu(dent->inum);
441 			ret = 1;
442 			goto out_free;
443 		}
444 
445 		/* Switch to the next entry */
446 		key_read(c, &dent->key, &key);
447 		nm.name = (char *)dent->name;
448 		dent = ubifs_tnc_next_ent(c, &key, &nm);
449 		if (IS_ERR(dent)) {
450 			err = PTR_ERR(dent);
451 			goto out;
452 		}
453 
454 		kfree(file->private_data);
455 		file->f_pos = key_hash_flash(c, &dent->key);
456 		file->private_data = dent;
457 		cond_resched();
458 	}
459 
460 out:
461 	if (err != -ENOENT)
462 		dbg_gen("cannot find next direntry, error %d", err);
463 
464 out_free:
465 	if (file->private_data)
466 		kfree(file->private_data);
467 	if (file)
468 		free(file);
469 	if (dentry)
470 		free(dentry);
471 	if (dir)
472 		free(dir);
473 
474 	return ret;
475 }
476 
477 static unsigned long ubifs_findfile(struct super_block *sb, char *filename)
478 {
479 	int ret;
480 	char *next;
481 	char fpath[128];
482 	char symlinkpath[128];
483 	char *name = fpath;
484 	unsigned long root_inum = 1;
485 	unsigned long inum;
486 	int symlink_count = 0; /* Don't allow symlink recursion */
487 	char link_name[64];
488 
489 	strcpy(fpath, filename);
490 
491 	/* Remove all leading slashes */
492 	while (*name == '/')
493 		name++;
494 
495 	/*
496 	 * Handle root-direcoty ('/')
497 	 */
498 	inum = root_inum;
499 	if (!name || *name == '\0')
500 		return inum;
501 
502 	for (;;) {
503 		struct inode *inode;
504 		struct ubifs_inode *ui;
505 
506 		/* Extract the actual part from the pathname.  */
507 		next = strchr(name, '/');
508 		if (next) {
509 			/* Remove all leading slashes.  */
510 			while (*next == '/')
511 				*(next++) = '\0';
512 		}
513 
514 		ret = ubifs_finddir(sb, name, root_inum, &inum);
515 		if (!ret)
516 			return 0;
517 		inode = ubifs_iget(sb, inum);
518 
519 		if (!inode)
520 			return 0;
521 		ui = ubifs_inode(inode);
522 
523 		if ((inode->i_mode & S_IFMT) == S_IFLNK) {
524 			char buf[128];
525 
526 			/* We have some sort of symlink recursion, bail out */
527 			if (symlink_count++ > 8) {
528 				printf("Symlink recursion, aborting\n");
529 				return 0;
530 			}
531 			memcpy(link_name, ui->data, ui->data_len);
532 			link_name[ui->data_len] = '\0';
533 
534 			if (link_name[0] == '/') {
535 				/* Absolute path, redo everything without
536 				 * the leading slash */
537 				next = name = link_name + 1;
538 				root_inum = 1;
539 				continue;
540 			}
541 			/* Relative to cur dir */
542 			sprintf(buf, "%s/%s",
543 					link_name, next == NULL ? "" : next);
544 			memcpy(symlinkpath, buf, sizeof(buf));
545 			next = name = symlinkpath;
546 			continue;
547 		}
548 
549 		/*
550 		 * Check if directory with this name exists
551 		 */
552 
553 		/* Found the node!  */
554 		if (!next || *next == '\0')
555 			return inum;
556 
557 		root_inum = inum;
558 		name = next;
559 	}
560 
561 	return 0;
562 }
563 
564 int ubifs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
565 {
566 	if (rbdd) {
567 		debug("UBIFS cannot be used with normal block devices\n");
568 		return -1;
569 	}
570 
571 	/*
572 	 * Should never happen since get_device_and_partition() already checks
573 	 * this, but better safe then sorry.
574 	 */
575 	if (!ubifs_is_mounted()) {
576 		debug("UBIFS not mounted, use ubifsmount to mount volume first!\n");
577 		return -1;
578 	}
579 
580 	return 0;
581 }
582 
583 int ubifs_ls(const char *filename)
584 {
585 	struct ubifs_info *c = ubifs_sb->s_fs_info;
586 	struct file *file;
587 	struct dentry *dentry;
588 	struct inode *dir;
589 	void *dirent = NULL;
590 	unsigned long inum;
591 	int ret = 0;
592 
593 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
594 	inum = ubifs_findfile(ubifs_sb, (char *)filename);
595 	if (!inum) {
596 		ret = -1;
597 		goto out;
598 	}
599 
600 	file = kzalloc(sizeof(struct file), 0);
601 	dentry = kzalloc(sizeof(struct dentry), 0);
602 	dir = kzalloc(sizeof(struct inode), 0);
603 	if (!file || !dentry || !dir) {
604 		printf("%s: Error, no memory for malloc!\n", __func__);
605 		ret = -ENOMEM;
606 		goto out_mem;
607 	}
608 
609 	dir->i_sb = ubifs_sb;
610 	file->f_path.dentry = dentry;
611 	file->f_path.dentry->d_parent = dentry;
612 	file->f_path.dentry->d_inode = dir;
613 	file->f_path.dentry->d_inode->i_ino = inum;
614 	file->f_pos = 1;
615 	file->private_data = NULL;
616 	ubifs_printdir(file, dirent);
617 
618 out_mem:
619 	if (file)
620 		free(file);
621 	if (dentry)
622 		free(dentry);
623 	if (dir)
624 		free(dir);
625 
626 out:
627 	ubi_close_volume(c->ubi);
628 	return ret;
629 }
630 
631 int ubifs_exists(const char *filename)
632 {
633 	struct ubifs_info *c = ubifs_sb->s_fs_info;
634 	unsigned long inum;
635 
636 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
637 	inum = ubifs_findfile(ubifs_sb, (char *)filename);
638 	ubi_close_volume(c->ubi);
639 
640 	return inum != 0;
641 }
642 
643 int ubifs_size(const char *filename, loff_t *size)
644 {
645 	struct ubifs_info *c = ubifs_sb->s_fs_info;
646 	unsigned long inum;
647 	struct inode *inode;
648 	int err = 0;
649 
650 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
651 
652 	inum = ubifs_findfile(ubifs_sb, (char *)filename);
653 	if (!inum) {
654 		err = -1;
655 		goto out;
656 	}
657 
658 	inode = ubifs_iget(ubifs_sb, inum);
659 	if (IS_ERR(inode)) {
660 		printf("%s: Error reading inode %ld!\n", __func__, inum);
661 		err = PTR_ERR(inode);
662 		goto out;
663 	}
664 
665 	*size = inode->i_size;
666 
667 	ubifs_iput(inode);
668 out:
669 	ubi_close_volume(c->ubi);
670 	return err;
671 }
672 
673 /*
674  * ubifsload...
675  */
676 
677 /* file.c */
678 
679 static inline void *kmap(struct page *page)
680 {
681 	return page->addr;
682 }
683 
684 static int read_block(struct inode *inode, void *addr, unsigned int block,
685 		      struct ubifs_data_node *dn)
686 {
687 	struct ubifs_info *c = inode->i_sb->s_fs_info;
688 	int err, len, out_len;
689 	union ubifs_key key;
690 	unsigned int dlen;
691 
692 	data_key_init(c, &key, inode->i_ino, block);
693 	err = ubifs_tnc_lookup(c, &key, dn);
694 	if (err) {
695 		if (err == -ENOENT)
696 			/* Not found, so it must be a hole */
697 			memset(addr, 0, UBIFS_BLOCK_SIZE);
698 		return err;
699 	}
700 
701 	ubifs_assert(le64_to_cpu(dn->ch.sqnum) > ubifs_inode(inode)->creat_sqnum);
702 
703 	len = le32_to_cpu(dn->size);
704 	if (len <= 0 || len > UBIFS_BLOCK_SIZE)
705 		goto dump;
706 
707 	dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
708 	out_len = UBIFS_BLOCK_SIZE;
709 	err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
710 			       le16_to_cpu(dn->compr_type));
711 	if (err || len != out_len)
712 		goto dump;
713 
714 	/*
715 	 * Data length can be less than a full block, even for blocks that are
716 	 * not the last in the file (e.g., as a result of making a hole and
717 	 * appending data). Ensure that the remainder is zeroed out.
718 	 */
719 	if (len < UBIFS_BLOCK_SIZE)
720 		memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
721 
722 	return 0;
723 
724 dump:
725 	ubifs_err(c, "bad data node (block %u, inode %lu)",
726 		  block, inode->i_ino);
727 	ubifs_dump_node(c, dn);
728 	return -EINVAL;
729 }
730 
731 static int do_readpage(struct ubifs_info *c, struct inode *inode,
732 		       struct page *page, int last_block_size)
733 {
734 	void *addr;
735 	int err = 0, i;
736 	unsigned int block, beyond;
737 	struct ubifs_data_node *dn;
738 	loff_t i_size = inode->i_size;
739 
740 	dbg_gen("ino %lu, pg %lu, i_size %lld",
741 		inode->i_ino, page->index, i_size);
742 
743 	addr = kmap(page);
744 
745 	block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
746 	beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
747 	if (block >= beyond) {
748 		/* Reading beyond inode */
749 		memset(addr, 0, PAGE_CACHE_SIZE);
750 		goto out;
751 	}
752 
753 	dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
754 	if (!dn)
755 		return -ENOMEM;
756 
757 	i = 0;
758 	while (1) {
759 		int ret;
760 
761 		if (block >= beyond) {
762 			/* Reading beyond inode */
763 			err = -ENOENT;
764 			memset(addr, 0, UBIFS_BLOCK_SIZE);
765 		} else {
766 			/*
767 			 * Reading last block? Make sure to not write beyond
768 			 * the requested size in the destination buffer.
769 			 */
770 			if (((block + 1) == beyond) || last_block_size) {
771 				void *buff;
772 				int dlen;
773 
774 				/*
775 				 * We need to buffer the data locally for the
776 				 * last block. This is to not pad the
777 				 * destination area to a multiple of
778 				 * UBIFS_BLOCK_SIZE.
779 				 */
780 				buff = malloc_cache_aligned(UBIFS_BLOCK_SIZE);
781 				if (!buff) {
782 					printf("%s: Error, malloc fails!\n",
783 					       __func__);
784 					err = -ENOMEM;
785 					break;
786 				}
787 
788 				/* Read block-size into temp buffer */
789 				ret = read_block(inode, buff, block, dn);
790 				if (ret) {
791 					err = ret;
792 					if (err != -ENOENT) {
793 						free(buff);
794 						break;
795 					}
796 				}
797 
798 				if (last_block_size)
799 					dlen = last_block_size;
800 				else
801 					dlen = le32_to_cpu(dn->size);
802 
803 				/* Now copy required size back to dest */
804 				memcpy(addr, buff, dlen);
805 
806 				free(buff);
807 			} else {
808 				ret = read_block(inode, addr, block, dn);
809 				if (ret) {
810 					err = ret;
811 					if (err != -ENOENT)
812 						break;
813 				}
814 			}
815 		}
816 		if (++i >= UBIFS_BLOCKS_PER_PAGE)
817 			break;
818 		block += 1;
819 		addr += UBIFS_BLOCK_SIZE;
820 	}
821 	if (err) {
822 		if (err == -ENOENT) {
823 			/* Not found, so it must be a hole */
824 			dbg_gen("hole");
825 			goto out_free;
826 		}
827 		ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
828 			  page->index, inode->i_ino, err);
829 		goto error;
830 	}
831 
832 out_free:
833 	kfree(dn);
834 out:
835 	return 0;
836 
837 error:
838 	kfree(dn);
839 	return err;
840 }
841 
842 int ubifs_read(const char *filename, void *buf, loff_t offset,
843 	       loff_t size, loff_t *actread)
844 {
845 	struct ubifs_info *c = ubifs_sb->s_fs_info;
846 	unsigned long inum;
847 	struct inode *inode;
848 	struct page page;
849 	int err = 0;
850 	int i;
851 	int count;
852 	int last_block_size = 0;
853 
854 	*actread = 0;
855 
856 	if (offset & (PAGE_SIZE - 1)) {
857 		printf("ubifs: Error offset must be a multple of %d\n",
858 		       PAGE_SIZE);
859 		return -1;
860 	}
861 
862 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
863 	/* ubifs_findfile will resolve symlinks, so we know that we get
864 	 * the real file here */
865 	inum = ubifs_findfile(ubifs_sb, (char *)filename);
866 	if (!inum) {
867 		err = -1;
868 		goto out;
869 	}
870 
871 	/*
872 	 * Read file inode
873 	 */
874 	inode = ubifs_iget(ubifs_sb, inum);
875 	if (IS_ERR(inode)) {
876 		printf("%s: Error reading inode %ld!\n", __func__, inum);
877 		err = PTR_ERR(inode);
878 		goto out;
879 	}
880 
881 	if (offset > inode->i_size) {
882 		printf("ubifs: Error offset (%lld) > file-size (%lld)\n",
883 		       offset, size);
884 		err = -1;
885 		goto put_inode;
886 	}
887 
888 	/*
889 	 * If no size was specified or if size bigger than filesize
890 	 * set size to filesize
891 	 */
892 	if ((size == 0) || (size > (inode->i_size - offset)))
893 		size = inode->i_size - offset;
894 
895 	count = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
896 
897 	page.addr = buf;
898 	page.index = offset / PAGE_SIZE;
899 	page.inode = inode;
900 	for (i = 0; i < count; i++) {
901 		/*
902 		 * Make sure to not read beyond the requested size
903 		 */
904 		if (((i + 1) == count) && (size < inode->i_size))
905 			last_block_size = size - (i * PAGE_SIZE);
906 
907 		err = do_readpage(c, inode, &page, last_block_size);
908 		if (err)
909 			break;
910 
911 		page.addr += PAGE_SIZE;
912 		page.index++;
913 	}
914 
915 	if (err) {
916 		printf("Error reading file '%s'\n", filename);
917 		*actread = i * PAGE_SIZE;
918 	} else {
919 		*actread = size;
920 	}
921 
922 put_inode:
923 	ubifs_iput(inode);
924 
925 out:
926 	ubi_close_volume(c->ubi);
927 	return err;
928 }
929 
930 void ubifs_close(void)
931 {
932 }
933 
934 /* Compat wrappers for common/cmd_ubifs.c */
935 int ubifs_load(char *filename, u32 addr, u32 size)
936 {
937 	loff_t actread;
938 	int err;
939 
940 	printf("Loading file '%s' to addr 0x%08x...\n", filename, addr);
941 
942 	err = ubifs_read(filename, (void *)addr, 0, size, &actread);
943 	if (err == 0) {
944 		setenv_hex("filesize", actread);
945 		printf("Done\n");
946 	}
947 
948 	return err;
949 }
950 
951 void uboot_ubifs_umount(void)
952 {
953 	if (ubifs_sb) {
954 		printf("Unmounting UBIFS volume %s!\n",
955 		       ((struct ubifs_info *)(ubifs_sb->s_fs_info))->vi.name);
956 		ubifs_umount(ubifs_sb->s_fs_info);
957 		ubifs_sb = NULL;
958 	}
959 }
960