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1/*
2 * linux/fs/befs/linuxvfs.c
3 *
4 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
5 *
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/fs.h>
13#include <linux/errno.h>
14#include <linux/stat.h>
15#include <linux/nls.h>
16#include <linux/buffer_head.h>
17#include <linux/vfs.h>
18#include <linux/parser.h>
19#include <linux/namei.h>
20#include <linux/sched.h>
21
22#include "befs.h"
23#include "btree.h"
24#include "inode.h"
25#include "datastream.h"
26#include "super.h"
27#include "io.h"
28
29MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
30MODULE_AUTHOR("Will Dyson");
31MODULE_LICENSE("GPL");
32
33/* The units the vfs expects inode->i_blocks to be in */
34#define VFS_BLOCK_SIZE 512
35
36static int befs_readdir(struct file *, struct dir_context *);
37static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
38static int befs_readpage(struct file *file, struct page *page);
39static sector_t befs_bmap(struct address_space *mapping, sector_t block);
40static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
41static struct inode *befs_iget(struct super_block *, unsigned long);
42static struct inode *befs_alloc_inode(struct super_block *sb);
43static void befs_destroy_inode(struct inode *inode);
44static void befs_destroy_inodecache(void);
45static int befs_symlink_readpage(struct file *, struct page *);
46static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
47 char **out, int *out_len);
48static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
49 char **out, int *out_len);
50static void befs_put_super(struct super_block *);
51static int befs_remount(struct super_block *, int *, char *);
52static int befs_statfs(struct dentry *, struct kstatfs *);
53static int parse_options(char *, struct befs_mount_options *);
54
55static const struct super_operations befs_sops = {
56 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
57 .destroy_inode = befs_destroy_inode, /* deallocate an inode */
58 .put_super = befs_put_super, /* uninit super */
59 .statfs = befs_statfs, /* statfs */
60 .remount_fs = befs_remount,
61 .show_options = generic_show_options,
62};
63
64/* slab cache for befs_inode_info objects */
65static struct kmem_cache *befs_inode_cachep;
66
67static const struct file_operations befs_dir_operations = {
68 .read = generic_read_dir,
69 .iterate = befs_readdir,
70 .llseek = generic_file_llseek,
71};
72
73static const struct inode_operations befs_dir_inode_operations = {
74 .lookup = befs_lookup,
75};
76
77static const struct address_space_operations befs_aops = {
78 .readpage = befs_readpage,
79 .bmap = befs_bmap,
80};
81
82static const struct address_space_operations befs_symlink_aops = {
83 .readpage = befs_symlink_readpage,
84};
85
86/*
87 * Called by generic_file_read() to read a page of data
88 *
89 * In turn, simply calls a generic block read function and
90 * passes it the address of befs_get_block, for mapping file
91 * positions to disk blocks.
92 */
93static int
94befs_readpage(struct file *file, struct page *page)
95{
96 return block_read_full_page(page, befs_get_block);
97}
98
99static sector_t
100befs_bmap(struct address_space *mapping, sector_t block)
101{
102 return generic_block_bmap(mapping, block, befs_get_block);
103}
104
105/*
106 * Generic function to map a file position (block) to a
107 * disk offset (passed back in bh_result).
108 *
109 * Used by many higher level functions.
110 *
111 * Calls befs_fblock2brun() in datastream.c to do the real work.
112 *
113 * -WD 10-26-01
114 */
115
116static int
117befs_get_block(struct inode *inode, sector_t block,
118 struct buffer_head *bh_result, int create)
119{
120 struct super_block *sb = inode->i_sb;
121 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
122 befs_block_run run = BAD_IADDR;
123 int res = 0;
124 ulong disk_off;
125
126 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
127 (unsigned long)inode->i_ino, (long)block);
128 if (create) {
129 befs_error(sb, "befs_get_block() was asked to write to "
130 "block %ld in inode %lu", (long)block,
131 (unsigned long)inode->i_ino);
132 return -EPERM;
133 }
134
135 res = befs_fblock2brun(sb, ds, block, &run);
136 if (res != BEFS_OK) {
137 befs_error(sb,
138 "<--- %s for inode %lu, block %ld ERROR",
139 __func__, (unsigned long)inode->i_ino,
140 (long)block);
141 return -EFBIG;
142 }
143
144 disk_off = (ulong) iaddr2blockno(sb, &run);
145
146 map_bh(bh_result, inode->i_sb, disk_off);
147
148 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
149 __func__, (unsigned long)inode->i_ino, (long)block,
150 (unsigned long)disk_off);
151
152 return 0;
153}
154
155static struct dentry *
156befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
157{
158 struct inode *inode = NULL;
159 struct super_block *sb = dir->i_sb;
160 befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
161 befs_off_t offset;
162 int ret;
163 int utfnamelen;
164 char *utfname;
165 const char *name = dentry->d_name.name;
166
167 befs_debug(sb, "---> %s name %pd inode %ld", __func__,
168 dentry, dir->i_ino);
169
170 /* Convert to UTF-8 */
171 if (BEFS_SB(sb)->nls) {
172 ret =
173 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
174 if (ret < 0) {
175 befs_debug(sb, "<--- %s ERROR", __func__);
176 return ERR_PTR(ret);
177 }
178 ret = befs_btree_find(sb, ds, utfname, &offset);
179 kfree(utfname);
180
181 } else {
182 ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
183 }
184
185 if (ret == BEFS_BT_NOT_FOUND) {
186 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
187 return ERR_PTR(-ENOENT);
188
189 } else if (ret != BEFS_OK || offset == 0) {
190 befs_warning(sb, "<--- %s Error", __func__);
191 return ERR_PTR(-ENODATA);
192 }
193
194 inode = befs_iget(dir->i_sb, (ino_t) offset);
195 if (IS_ERR(inode))
196 return ERR_CAST(inode);
197
198 d_add(dentry, inode);
199
200 befs_debug(sb, "<--- %s", __func__);
201
202 return NULL;
203}
204
205static int
206befs_readdir(struct file *file, struct dir_context *ctx)
207{
208 struct inode *inode = file_inode(file);
209 struct super_block *sb = inode->i_sb;
210 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
211 befs_off_t value;
212 int result;
213 size_t keysize;
214 unsigned char d_type;
215 char keybuf[BEFS_NAME_LEN + 1];
216
217 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
218 __func__, file, inode->i_ino, ctx->pos);
219
220more:
221 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
222 keybuf, &keysize, &value);
223
224 if (result == BEFS_ERR) {
225 befs_debug(sb, "<--- %s ERROR", __func__);
226 befs_error(sb, "IO error reading %pD (inode %lu)",
227 file, inode->i_ino);
228 return -EIO;
229
230 } else if (result == BEFS_BT_END) {
231 befs_debug(sb, "<--- %s END", __func__);
232 return 0;
233
234 } else if (result == BEFS_BT_EMPTY) {
235 befs_debug(sb, "<--- %s Empty directory", __func__);
236 return 0;
237 }
238
239 d_type = DT_UNKNOWN;
240
241 /* Convert to NLS */
242 if (BEFS_SB(sb)->nls) {
243 char *nlsname;
244 int nlsnamelen;
245 result =
246 befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
247 if (result < 0) {
248 befs_debug(sb, "<--- %s ERROR", __func__);
249 return result;
250 }
251 if (!dir_emit(ctx, nlsname, nlsnamelen,
252 (ino_t) value, d_type)) {
253 kfree(nlsname);
254 return 0;
255 }
256 kfree(nlsname);
257 } else {
258 if (!dir_emit(ctx, keybuf, keysize,
259 (ino_t) value, d_type))
260 return 0;
261 }
262 ctx->pos++;
263 goto more;
264}
265
266static struct inode *
267befs_alloc_inode(struct super_block *sb)
268{
269 struct befs_inode_info *bi;
270
271 bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
272 if (!bi)
273 return NULL;
274 return &bi->vfs_inode;
275}
276
277static void befs_i_callback(struct rcu_head *head)
278{
279 struct inode *inode = container_of(head, struct inode, i_rcu);
280 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
281}
282
283static void befs_destroy_inode(struct inode *inode)
284{
285 call_rcu(&inode->i_rcu, befs_i_callback);
286}
287
288static void init_once(void *foo)
289{
290 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
291
292 inode_init_once(&bi->vfs_inode);
293}
294
295static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
296{
297 struct buffer_head *bh = NULL;
298 befs_inode *raw_inode = NULL;
299 struct befs_sb_info *befs_sb = BEFS_SB(sb);
300 struct befs_inode_info *befs_ino = NULL;
301 struct inode *inode;
302 long ret = -EIO;
303
304 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
305
306 inode = iget_locked(sb, ino);
307 if (!inode)
308 return ERR_PTR(-ENOMEM);
309 if (!(inode->i_state & I_NEW))
310 return inode;
311
312 befs_ino = BEFS_I(inode);
313
314 /* convert from vfs's inode number to befs's inode number */
315 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
316
317 befs_debug(sb, " real inode number [%u, %hu, %hu]",
318 befs_ino->i_inode_num.allocation_group,
319 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
320
321 bh = befs_bread(sb, inode->i_ino);
322 if (!bh) {
323 befs_error(sb, "unable to read inode block - "
324 "inode = %lu", inode->i_ino);
325 goto unacquire_none;
326 }
327
328 raw_inode = (befs_inode *) bh->b_data;
329
330 befs_dump_inode(sb, raw_inode);
331
332 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
333 befs_error(sb, "Bad inode: %lu", inode->i_ino);
334 goto unacquire_bh;
335 }
336
337 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
338
339 /*
340 * set uid and gid. But since current BeOS is single user OS, so
341 * you can change by "uid" or "gid" options.
342 */
343
344 inode->i_uid = befs_sb->mount_opts.use_uid ?
345 befs_sb->mount_opts.uid :
346 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
347 inode->i_gid = befs_sb->mount_opts.use_gid ?
348 befs_sb->mount_opts.gid :
349 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
350
351 set_nlink(inode, 1);
352
353 /*
354 * BEFS's time is 64 bits, but current VFS is 32 bits...
355 * BEFS don't have access time. Nor inode change time. VFS
356 * doesn't have creation time.
357 * Also, the lower 16 bits of the last_modified_time and
358 * create_time are just a counter to help ensure uniqueness
359 * for indexing purposes. (PFD, page 54)
360 */
361
362 inode->i_mtime.tv_sec =
363 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
364 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
365 inode->i_ctime = inode->i_mtime;
366 inode->i_atime = inode->i_mtime;
367
368 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
369 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
370 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
371 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
372
373 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
374 inode->i_size = 0;
375 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
376 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
377 BEFS_SYMLINK_LEN);
378 } else {
379 int num_blks;
380
381 befs_ino->i_data.ds =
382 fsds_to_cpu(sb, &raw_inode->data.datastream);
383
384 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
385 inode->i_blocks =
386 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
387 inode->i_size = befs_ino->i_data.ds.size;
388 }
389
390 inode->i_mapping->a_ops = &befs_aops;
391
392 if (S_ISREG(inode->i_mode)) {
393 inode->i_fop = &generic_ro_fops;
394 } else if (S_ISDIR(inode->i_mode)) {
395 inode->i_op = &befs_dir_inode_operations;
396 inode->i_fop = &befs_dir_operations;
397 } else if (S_ISLNK(inode->i_mode)) {
398 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
399 inode->i_op = &page_symlink_inode_operations;
400 inode_nohighmem(inode);
401 inode->i_mapping->a_ops = &befs_symlink_aops;
402 } else {
403 inode->i_link = befs_ino->i_data.symlink;
404 inode->i_op = &simple_symlink_inode_operations;
405 }
406 } else {
407 befs_error(sb, "Inode %lu is not a regular file, "
408 "directory or symlink. THAT IS WRONG! BeFS has no "
409 "on disk special files", inode->i_ino);
410 goto unacquire_bh;
411 }
412
413 brelse(bh);
414 befs_debug(sb, "<--- %s", __func__);
415 unlock_new_inode(inode);
416 return inode;
417
418 unacquire_bh:
419 brelse(bh);
420
421 unacquire_none:
422 iget_failed(inode);
423 befs_debug(sb, "<--- %s - Bad inode", __func__);
424 return ERR_PTR(ret);
425}
426
427/* Initialize the inode cache. Called at fs setup.
428 *
429 * Taken from NFS implementation by Al Viro.
430 */
431static int __init
432befs_init_inodecache(void)
433{
434 befs_inode_cachep = kmem_cache_create("befs_inode_cache",
435 sizeof (struct befs_inode_info),
436 0, (SLAB_RECLAIM_ACCOUNT|
437 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
438 init_once);
439 if (befs_inode_cachep == NULL) {
440 pr_err("%s: Couldn't initialize inode slabcache\n", __func__);
441 return -ENOMEM;
442 }
443 return 0;
444}
445
446/* Called at fs teardown.
447 *
448 * Taken from NFS implementation by Al Viro.
449 */
450static void
451befs_destroy_inodecache(void)
452{
453 /*
454 * Make sure all delayed rcu free inodes are flushed before we
455 * destroy cache.
456 */
457 rcu_barrier();
458 kmem_cache_destroy(befs_inode_cachep);
459}
460
461/*
462 * The inode of symbolic link is different to data stream.
463 * The data stream become link name. Unless the LONG_SYMLINK
464 * flag is set.
465 */
466static int befs_symlink_readpage(struct file *unused, struct page *page)
467{
468 struct inode *inode = page->mapping->host;
469 struct super_block *sb = inode->i_sb;
470 struct befs_inode_info *befs_ino = BEFS_I(inode);
471 befs_data_stream *data = &befs_ino->i_data.ds;
472 befs_off_t len = data->size;
473 char *link = page_address(page);
474
475 if (len == 0 || len > PAGE_SIZE) {
476 befs_error(sb, "Long symlink with illegal length");
477 goto fail;
478 }
479 befs_debug(sb, "Follow long symlink");
480
481 if (befs_read_lsymlink(sb, data, link, len) != len) {
482 befs_error(sb, "Failed to read entire long symlink");
483 goto fail;
484 }
485 link[len - 1] = '\0';
486 SetPageUptodate(page);
487 unlock_page(page);
488 return 0;
489fail:
490 SetPageError(page);
491 unlock_page(page);
492 return -EIO;
493}
494
495/*
496 * UTF-8 to NLS charset convert routine
497 *
498 *
499 * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
500 * the nls tables directly
501 */
502
503static int
504befs_utf2nls(struct super_block *sb, const char *in,
505 int in_len, char **out, int *out_len)
506{
507 struct nls_table *nls = BEFS_SB(sb)->nls;
508 int i, o;
509 unicode_t uni;
510 int unilen, utflen;
511 char *result;
512 /* The utf8->nls conversion won't make the final nls string bigger
513 * than the utf one, but if the string is pure ascii they'll have the
514 * same width and an extra char is needed to save the additional \0
515 */
516 int maxlen = in_len + 1;
517
518 befs_debug(sb, "---> %s", __func__);
519
520 if (!nls) {
521 befs_error(sb, "%s called with no NLS table loaded", __func__);
522 return -EINVAL;
523 }
524
525 *out = result = kmalloc(maxlen, GFP_NOFS);
526 if (!*out) {
527 befs_error(sb, "%s cannot allocate memory", __func__);
528 *out_len = 0;
529 return -ENOMEM;
530 }
531
532 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
533
534 /* convert from UTF-8 to Unicode */
535 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
536 if (utflen < 0)
537 goto conv_err;
538
539 /* convert from Unicode to nls */
540 if (uni > MAX_WCHAR_T)
541 goto conv_err;
542 unilen = nls->uni2char(uni, &result[o], in_len - o);
543 if (unilen < 0)
544 goto conv_err;
545 }
546 result[o] = '\0';
547 *out_len = o;
548
549 befs_debug(sb, "<--- %s", __func__);
550
551 return o;
552
553 conv_err:
554 befs_error(sb, "Name using character set %s contains a character that "
555 "cannot be converted to unicode.", nls->charset);
556 befs_debug(sb, "<--- %s", __func__);
557 kfree(result);
558 return -EILSEQ;
559}
560
561/**
562 * befs_nls2utf - Convert NLS string to utf8 encodeing
563 * @sb: Superblock
564 * @in: Input string buffer in NLS format
565 * @in_len: Length of input string in bytes
566 * @out: The output string in UTF-8 format
567 * @out_len: Length of the output buffer
568 *
569 * Converts input string @in, which is in the format of the loaded NLS map,
570 * into a utf8 string.
571 *
572 * The destination string @out is allocated by this function and the caller is
573 * responsible for freeing it with kfree()
574 *
575 * On return, *@out_len is the length of @out in bytes.
576 *
577 * On success, the return value is the number of utf8 characters written to
578 * the output buffer @out.
579 *
580 * On Failure, a negative number coresponding to the error code is returned.
581 */
582
583static int
584befs_nls2utf(struct super_block *sb, const char *in,
585 int in_len, char **out, int *out_len)
586{
587 struct nls_table *nls = BEFS_SB(sb)->nls;
588 int i, o;
589 wchar_t uni;
590 int unilen, utflen;
591 char *result;
592 /* There're nls characters that will translate to 3-chars-wide UTF-8
593 * characters, a additional byte is needed to save the final \0
594 * in special cases */
595 int maxlen = (3 * in_len) + 1;
596
597 befs_debug(sb, "---> %s\n", __func__);
598
599 if (!nls) {
600 befs_error(sb, "%s called with no NLS table loaded.",
601 __func__);
602 return -EINVAL;
603 }
604
605 *out = result = kmalloc(maxlen, GFP_NOFS);
606 if (!*out) {
607 befs_error(sb, "%s cannot allocate memory", __func__);
608 *out_len = 0;
609 return -ENOMEM;
610 }
611
612 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
613
614 /* convert from nls to unicode */
615 unilen = nls->char2uni(&in[i], in_len - i, &uni);
616 if (unilen < 0)
617 goto conv_err;
618
619 /* convert from unicode to UTF-8 */
620 utflen = utf32_to_utf8(uni, &result[o], 3);
621 if (utflen <= 0)
622 goto conv_err;
623 }
624
625 result[o] = '\0';
626 *out_len = o;
627
628 befs_debug(sb, "<--- %s", __func__);
629
630 return i;
631
632 conv_err:
633 befs_error(sb, "Name using charecter set %s contains a charecter that "
634 "cannot be converted to unicode.", nls->charset);
635 befs_debug(sb, "<--- %s", __func__);
636 kfree(result);
637 return -EILSEQ;
638}
639
640/**
641 * Use the
642 *
643 */
644enum {
645 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
646};
647
648static const match_table_t befs_tokens = {
649 {Opt_uid, "uid=%d"},
650 {Opt_gid, "gid=%d"},
651 {Opt_charset, "iocharset=%s"},
652 {Opt_debug, "debug"},
653 {Opt_err, NULL}
654};
655
656static int
657parse_options(char *options, struct befs_mount_options *opts)
658{
659 char *p;
660 substring_t args[MAX_OPT_ARGS];
661 int option;
662 kuid_t uid;
663 kgid_t gid;
664
665 /* Initialize options */
666 opts->uid = GLOBAL_ROOT_UID;
667 opts->gid = GLOBAL_ROOT_GID;
668 opts->use_uid = 0;
669 opts->use_gid = 0;
670 opts->iocharset = NULL;
671 opts->debug = 0;
672
673 if (!options)
674 return 1;
675
676 while ((p = strsep(&options, ",")) != NULL) {
677 int token;
678 if (!*p)
679 continue;
680
681 token = match_token(p, befs_tokens, args);
682 switch (token) {
683 case Opt_uid:
684 if (match_int(&args[0], &option))
685 return 0;
686 uid = INVALID_UID;
687 if (option >= 0)
688 uid = make_kuid(current_user_ns(), option);
689 if (!uid_valid(uid)) {
690 pr_err("Invalid uid %d, "
691 "using default\n", option);
692 break;
693 }
694 opts->uid = uid;
695 opts->use_uid = 1;
696 break;
697 case Opt_gid:
698 if (match_int(&args[0], &option))
699 return 0;
700 gid = INVALID_GID;
701 if (option >= 0)
702 gid = make_kgid(current_user_ns(), option);
703 if (!gid_valid(gid)) {
704 pr_err("Invalid gid %d, "
705 "using default\n", option);
706 break;
707 }
708 opts->gid = gid;
709 opts->use_gid = 1;
710 break;
711 case Opt_charset:
712 kfree(opts->iocharset);
713 opts->iocharset = match_strdup(&args[0]);
714 if (!opts->iocharset) {
715 pr_err("allocation failure for "
716 "iocharset string\n");
717 return 0;
718 }
719 break;
720 case Opt_debug:
721 opts->debug = 1;
722 break;
723 default:
724 pr_err("Unrecognized mount option \"%s\" "
725 "or missing value\n", p);
726 return 0;
727 }
728 }
729 return 1;
730}
731
732/* This function has the responsibiltiy of getting the
733 * filesystem ready for unmounting.
734 * Basically, we free everything that we allocated in
735 * befs_read_inode
736 */
737static void
738befs_put_super(struct super_block *sb)
739{
740 kfree(BEFS_SB(sb)->mount_opts.iocharset);
741 BEFS_SB(sb)->mount_opts.iocharset = NULL;
742 unload_nls(BEFS_SB(sb)->nls);
743 kfree(sb->s_fs_info);
744 sb->s_fs_info = NULL;
745}
746
747/* Allocate private field of the superblock, fill it.
748 *
749 * Finish filling the public superblock fields
750 * Make the root directory
751 * Load a set of NLS translations if needed.
752 */
753static int
754befs_fill_super(struct super_block *sb, void *data, int silent)
755{
756 struct buffer_head *bh;
757 struct befs_sb_info *befs_sb;
758 befs_super_block *disk_sb;
759 struct inode *root;
760 long ret = -EINVAL;
761 const unsigned long sb_block = 0;
762 const off_t x86_sb_off = 512;
763
764 save_mount_options(sb, data);
765
766 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
767 if (sb->s_fs_info == NULL) {
768 pr_err("(%s): Unable to allocate memory for private "
769 "portion of superblock. Bailing.\n", sb->s_id);
770 goto unacquire_none;
771 }
772 befs_sb = BEFS_SB(sb);
773
774 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
775 befs_error(sb, "cannot parse mount options");
776 goto unacquire_priv_sbp;
777 }
778
779 befs_debug(sb, "---> %s", __func__);
780
781 if (!(sb->s_flags & MS_RDONLY)) {
782 befs_warning(sb,
783 "No write support. Marking filesystem read-only");
784 sb->s_flags |= MS_RDONLY;
785 }
786
787 /*
788 * Set dummy blocksize to read super block.
789 * Will be set to real fs blocksize later.
790 *
791 * Linux 2.4.10 and later refuse to read blocks smaller than
792 * the hardsect size for the device. But we also need to read at
793 * least 1k to get the second 512 bytes of the volume.
794 * -WD 10-26-01
795 */
796 sb_min_blocksize(sb, 1024);
797
798 if (!(bh = sb_bread(sb, sb_block))) {
799 befs_error(sb, "unable to read superblock");
800 goto unacquire_priv_sbp;
801 }
802
803 /* account for offset of super block on x86 */
804 disk_sb = (befs_super_block *) bh->b_data;
805 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
806 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
807 befs_debug(sb, "Using PPC superblock location");
808 } else {
809 befs_debug(sb, "Using x86 superblock location");
810 disk_sb =
811 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
812 }
813
814 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
815 (befs_check_sb(sb) != BEFS_OK))
816 goto unacquire_bh;
817
818 befs_dump_super_block(sb, disk_sb);
819
820 brelse(bh);
821
822 if( befs_sb->num_blocks > ~((sector_t)0) ) {
823 befs_error(sb, "blocks count: %llu "
824 "is larger than the host can use",
825 befs_sb->num_blocks);
826 goto unacquire_priv_sbp;
827 }
828
829 /*
830 * set up enough so that it can read an inode
831 * Fill in kernel superblock fields from private sb
832 */
833 sb->s_magic = BEFS_SUPER_MAGIC;
834 /* Set real blocksize of fs */
835 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
836 sb->s_op = &befs_sops;
837 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
838 if (IS_ERR(root)) {
839 ret = PTR_ERR(root);
840 goto unacquire_priv_sbp;
841 }
842 sb->s_root = d_make_root(root);
843 if (!sb->s_root) {
844 befs_error(sb, "get root inode failed");
845 goto unacquire_priv_sbp;
846 }
847
848 /* load nls library */
849 if (befs_sb->mount_opts.iocharset) {
850 befs_debug(sb, "Loading nls: %s",
851 befs_sb->mount_opts.iocharset);
852 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
853 if (!befs_sb->nls) {
854 befs_warning(sb, "Cannot load nls %s"
855 " loading default nls",
856 befs_sb->mount_opts.iocharset);
857 befs_sb->nls = load_nls_default();
858 }
859 /* load default nls if none is specified in mount options */
860 } else {
861 befs_debug(sb, "Loading default nls");
862 befs_sb->nls = load_nls_default();
863 }
864
865 return 0;
866/*****************/
867 unacquire_bh:
868 brelse(bh);
869
870 unacquire_priv_sbp:
871 kfree(befs_sb->mount_opts.iocharset);
872 kfree(sb->s_fs_info);
873
874 unacquire_none:
875 sb->s_fs_info = NULL;
876 return ret;
877}
878
879static int
880befs_remount(struct super_block *sb, int *flags, char *data)
881{
882 sync_filesystem(sb);
883 if (!(*flags & MS_RDONLY))
884 return -EINVAL;
885 return 0;
886}
887
888static int
889befs_statfs(struct dentry *dentry, struct kstatfs *buf)
890{
891 struct super_block *sb = dentry->d_sb;
892 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
893
894 befs_debug(sb, "---> %s", __func__);
895
896 buf->f_type = BEFS_SUPER_MAGIC;
897 buf->f_bsize = sb->s_blocksize;
898 buf->f_blocks = BEFS_SB(sb)->num_blocks;
899 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
900 buf->f_bavail = buf->f_bfree;
901 buf->f_files = 0; /* UNKNOWN */
902 buf->f_ffree = 0; /* UNKNOWN */
903 buf->f_fsid.val[0] = (u32)id;
904 buf->f_fsid.val[1] = (u32)(id >> 32);
905 buf->f_namelen = BEFS_NAME_LEN;
906
907 befs_debug(sb, "<--- %s", __func__);
908
909 return 0;
910}
911
912static struct dentry *
913befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
914 void *data)
915{
916 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
917}
918
919static struct file_system_type befs_fs_type = {
920 .owner = THIS_MODULE,
921 .name = "befs",
922 .mount = befs_mount,
923 .kill_sb = kill_block_super,
924 .fs_flags = FS_REQUIRES_DEV,
925};
926MODULE_ALIAS_FS("befs");
927
928static int __init
929init_befs_fs(void)
930{
931 int err;
932
933 pr_info("version: %s\n", BEFS_VERSION);
934
935 err = befs_init_inodecache();
936 if (err)
937 goto unacquire_none;
938
939 err = register_filesystem(&befs_fs_type);
940 if (err)
941 goto unacquire_inodecache;
942
943 return 0;
944
945unacquire_inodecache:
946 befs_destroy_inodecache();
947
948unacquire_none:
949 return err;
950}
951
952static void __exit
953exit_befs_fs(void)
954{
955 befs_destroy_inodecache();
956
957 unregister_filesystem(&befs_fs_type);
958}
959
960/*
961Macros that typecheck the init and exit functions,
962ensures that they are called at init and cleanup,
963and eliminates warnings about unused functions.
964*/
965module_init(init_befs_fs)
966module_exit(exit_befs_fs)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/befs/linuxvfs.c
4 *
5 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
6 *
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/errno.h>
15#include <linux/stat.h>
16#include <linux/nls.h>
17#include <linux/buffer_head.h>
18#include <linux/vfs.h>
19#include <linux/parser.h>
20#include <linux/namei.h>
21#include <linux/sched.h>
22#include <linux/cred.h>
23#include <linux/exportfs.h>
24#include <linux/seq_file.h>
25#include <linux/blkdev.h>
26
27#include "befs.h"
28#include "btree.h"
29#include "inode.h"
30#include "datastream.h"
31#include "super.h"
32#include "io.h"
33
34MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
35MODULE_AUTHOR("Will Dyson");
36MODULE_LICENSE("GPL");
37
38/* The units the vfs expects inode->i_blocks to be in */
39#define VFS_BLOCK_SIZE 512
40
41static int befs_readdir(struct file *, struct dir_context *);
42static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
43static int befs_read_folio(struct file *file, struct folio *folio);
44static sector_t befs_bmap(struct address_space *mapping, sector_t block);
45static struct dentry *befs_lookup(struct inode *, struct dentry *,
46 unsigned int);
47static struct inode *befs_iget(struct super_block *, unsigned long);
48static struct inode *befs_alloc_inode(struct super_block *sb);
49static void befs_free_inode(struct inode *inode);
50static void befs_destroy_inodecache(void);
51static int befs_symlink_read_folio(struct file *, struct folio *);
52static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
53 char **out, int *out_len);
54static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
55 char **out, int *out_len);
56static void befs_put_super(struct super_block *);
57static int befs_remount(struct super_block *, int *, char *);
58static int befs_statfs(struct dentry *, struct kstatfs *);
59static int befs_show_options(struct seq_file *, struct dentry *);
60static int parse_options(char *, struct befs_mount_options *);
61static struct dentry *befs_fh_to_dentry(struct super_block *sb,
62 struct fid *fid, int fh_len, int fh_type);
63static struct dentry *befs_fh_to_parent(struct super_block *sb,
64 struct fid *fid, int fh_len, int fh_type);
65static struct dentry *befs_get_parent(struct dentry *child);
66
67static const struct super_operations befs_sops = {
68 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
69 .free_inode = befs_free_inode, /* deallocate an inode */
70 .put_super = befs_put_super, /* uninit super */
71 .statfs = befs_statfs, /* statfs */
72 .remount_fs = befs_remount,
73 .show_options = befs_show_options,
74};
75
76/* slab cache for befs_inode_info objects */
77static struct kmem_cache *befs_inode_cachep;
78
79static const struct file_operations befs_dir_operations = {
80 .read = generic_read_dir,
81 .iterate_shared = befs_readdir,
82 .llseek = generic_file_llseek,
83};
84
85static const struct inode_operations befs_dir_inode_operations = {
86 .lookup = befs_lookup,
87};
88
89static const struct address_space_operations befs_aops = {
90 .read_folio = befs_read_folio,
91 .bmap = befs_bmap,
92};
93
94static const struct address_space_operations befs_symlink_aops = {
95 .read_folio = befs_symlink_read_folio,
96};
97
98static const struct export_operations befs_export_operations = {
99 .fh_to_dentry = befs_fh_to_dentry,
100 .fh_to_parent = befs_fh_to_parent,
101 .get_parent = befs_get_parent,
102};
103
104/*
105 * Called by generic_file_read() to read a folio of data
106 *
107 * In turn, simply calls a generic block read function and
108 * passes it the address of befs_get_block, for mapping file
109 * positions to disk blocks.
110 */
111static int befs_read_folio(struct file *file, struct folio *folio)
112{
113 return block_read_full_folio(folio, befs_get_block);
114}
115
116static sector_t
117befs_bmap(struct address_space *mapping, sector_t block)
118{
119 return generic_block_bmap(mapping, block, befs_get_block);
120}
121
122/*
123 * Generic function to map a file position (block) to a
124 * disk offset (passed back in bh_result).
125 *
126 * Used by many higher level functions.
127 *
128 * Calls befs_fblock2brun() in datastream.c to do the real work.
129 */
130
131static int
132befs_get_block(struct inode *inode, sector_t block,
133 struct buffer_head *bh_result, int create)
134{
135 struct super_block *sb = inode->i_sb;
136 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
137 befs_block_run run = BAD_IADDR;
138 int res;
139 ulong disk_off;
140
141 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
142 (unsigned long)inode->i_ino, (long)block);
143 if (create) {
144 befs_error(sb, "befs_get_block() was asked to write to "
145 "block %ld in inode %lu", (long)block,
146 (unsigned long)inode->i_ino);
147 return -EPERM;
148 }
149
150 res = befs_fblock2brun(sb, ds, block, &run);
151 if (res != BEFS_OK) {
152 befs_error(sb,
153 "<--- %s for inode %lu, block %ld ERROR",
154 __func__, (unsigned long)inode->i_ino,
155 (long)block);
156 return -EFBIG;
157 }
158
159 disk_off = (ulong) iaddr2blockno(sb, &run);
160
161 map_bh(bh_result, inode->i_sb, disk_off);
162
163 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
164 __func__, (unsigned long)inode->i_ino, (long)block,
165 (unsigned long)disk_off);
166
167 return 0;
168}
169
170static struct dentry *
171befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
172{
173 struct inode *inode;
174 struct super_block *sb = dir->i_sb;
175 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
176 befs_off_t offset;
177 int ret;
178 int utfnamelen;
179 char *utfname;
180 const char *name = dentry->d_name.name;
181
182 befs_debug(sb, "---> %s name %pd inode %ld", __func__,
183 dentry, dir->i_ino);
184
185 /* Convert to UTF-8 */
186 if (BEFS_SB(sb)->nls) {
187 ret =
188 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
189 if (ret < 0) {
190 befs_debug(sb, "<--- %s ERROR", __func__);
191 return ERR_PTR(ret);
192 }
193 ret = befs_btree_find(sb, ds, utfname, &offset);
194 kfree(utfname);
195
196 } else {
197 ret = befs_btree_find(sb, ds, name, &offset);
198 }
199
200 if (ret == BEFS_BT_NOT_FOUND) {
201 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
202 inode = NULL;
203 } else if (ret != BEFS_OK || offset == 0) {
204 befs_error(sb, "<--- %s Error", __func__);
205 inode = ERR_PTR(-ENODATA);
206 } else {
207 inode = befs_iget(dir->i_sb, (ino_t) offset);
208 }
209 befs_debug(sb, "<--- %s", __func__);
210
211 return d_splice_alias(inode, dentry);
212}
213
214static int
215befs_readdir(struct file *file, struct dir_context *ctx)
216{
217 struct inode *inode = file_inode(file);
218 struct super_block *sb = inode->i_sb;
219 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
220 befs_off_t value;
221 int result;
222 size_t keysize;
223 char keybuf[BEFS_NAME_LEN + 1];
224
225 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
226 __func__, file, inode->i_ino, ctx->pos);
227
228 while (1) {
229 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
230 keybuf, &keysize, &value);
231
232 if (result == BEFS_ERR) {
233 befs_debug(sb, "<--- %s ERROR", __func__);
234 befs_error(sb, "IO error reading %pD (inode %lu)",
235 file, inode->i_ino);
236 return -EIO;
237
238 } else if (result == BEFS_BT_END) {
239 befs_debug(sb, "<--- %s END", __func__);
240 return 0;
241
242 } else if (result == BEFS_BT_EMPTY) {
243 befs_debug(sb, "<--- %s Empty directory", __func__);
244 return 0;
245 }
246
247 /* Convert to NLS */
248 if (BEFS_SB(sb)->nls) {
249 char *nlsname;
250 int nlsnamelen;
251
252 result =
253 befs_utf2nls(sb, keybuf, keysize, &nlsname,
254 &nlsnamelen);
255 if (result < 0) {
256 befs_debug(sb, "<--- %s ERROR", __func__);
257 return result;
258 }
259 if (!dir_emit(ctx, nlsname, nlsnamelen,
260 (ino_t) value, DT_UNKNOWN)) {
261 kfree(nlsname);
262 return 0;
263 }
264 kfree(nlsname);
265 } else {
266 if (!dir_emit(ctx, keybuf, keysize,
267 (ino_t) value, DT_UNKNOWN))
268 return 0;
269 }
270 ctx->pos++;
271 }
272}
273
274static struct inode *
275befs_alloc_inode(struct super_block *sb)
276{
277 struct befs_inode_info *bi;
278
279 bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL);
280 if (!bi)
281 return NULL;
282 return &bi->vfs_inode;
283}
284
285static void befs_free_inode(struct inode *inode)
286{
287 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
288}
289
290static void init_once(void *foo)
291{
292 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
293
294 inode_init_once(&bi->vfs_inode);
295}
296
297static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
298{
299 struct buffer_head *bh;
300 befs_inode *raw_inode;
301 struct befs_sb_info *befs_sb = BEFS_SB(sb);
302 struct befs_inode_info *befs_ino;
303 struct inode *inode;
304
305 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
306
307 inode = iget_locked(sb, ino);
308 if (!inode)
309 return ERR_PTR(-ENOMEM);
310 if (!(inode->i_state & I_NEW))
311 return inode;
312
313 befs_ino = BEFS_I(inode);
314
315 /* convert from vfs's inode number to befs's inode number */
316 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
317
318 befs_debug(sb, " real inode number [%u, %hu, %hu]",
319 befs_ino->i_inode_num.allocation_group,
320 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
321
322 bh = sb_bread(sb, inode->i_ino);
323 if (!bh) {
324 befs_error(sb, "unable to read inode block - "
325 "inode = %lu", inode->i_ino);
326 goto unacquire_none;
327 }
328
329 raw_inode = (befs_inode *) bh->b_data;
330
331 befs_dump_inode(sb, raw_inode);
332
333 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
334 befs_error(sb, "Bad inode: %lu", inode->i_ino);
335 goto unacquire_bh;
336 }
337
338 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
339
340 /*
341 * set uid and gid. But since current BeOS is single user OS, so
342 * you can change by "uid" or "gid" options.
343 */
344
345 inode->i_uid = befs_sb->mount_opts.use_uid ?
346 befs_sb->mount_opts.uid :
347 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
348 inode->i_gid = befs_sb->mount_opts.use_gid ?
349 befs_sb->mount_opts.gid :
350 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
351
352 set_nlink(inode, 1);
353
354 /*
355 * BEFS's time is 64 bits, but current VFS is 32 bits...
356 * BEFS don't have access time. Nor inode change time. VFS
357 * doesn't have creation time.
358 * Also, the lower 16 bits of the last_modified_time and
359 * create_time are just a counter to help ensure uniqueness
360 * for indexing purposes. (PFD, page 54)
361 */
362
363 inode->i_mtime.tv_sec =
364 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
365 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
366 inode->i_ctime = inode->i_mtime;
367 inode->i_atime = inode->i_mtime;
368
369 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
370 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
371 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
372 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
373
374 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
375 inode->i_size = 0;
376 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
377 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
378 BEFS_SYMLINK_LEN);
379 } else {
380 int num_blks;
381
382 befs_ino->i_data.ds =
383 fsds_to_cpu(sb, &raw_inode->data.datastream);
384
385 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
386 inode->i_blocks =
387 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
388 inode->i_size = befs_ino->i_data.ds.size;
389 }
390
391 inode->i_mapping->a_ops = &befs_aops;
392
393 if (S_ISREG(inode->i_mode)) {
394 inode->i_fop = &generic_ro_fops;
395 } else if (S_ISDIR(inode->i_mode)) {
396 inode->i_op = &befs_dir_inode_operations;
397 inode->i_fop = &befs_dir_operations;
398 } else if (S_ISLNK(inode->i_mode)) {
399 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
400 inode->i_op = &page_symlink_inode_operations;
401 inode_nohighmem(inode);
402 inode->i_mapping->a_ops = &befs_symlink_aops;
403 } else {
404 inode->i_link = befs_ino->i_data.symlink;
405 inode->i_op = &simple_symlink_inode_operations;
406 }
407 } else {
408 befs_error(sb, "Inode %lu is not a regular file, "
409 "directory or symlink. THAT IS WRONG! BeFS has no "
410 "on disk special files", inode->i_ino);
411 goto unacquire_bh;
412 }
413
414 brelse(bh);
415 befs_debug(sb, "<--- %s", __func__);
416 unlock_new_inode(inode);
417 return inode;
418
419unacquire_bh:
420 brelse(bh);
421
422unacquire_none:
423 iget_failed(inode);
424 befs_debug(sb, "<--- %s - Bad inode", __func__);
425 return ERR_PTR(-EIO);
426}
427
428/* Initialize the inode cache. Called at fs setup.
429 *
430 * Taken from NFS implementation by Al Viro.
431 */
432static int __init
433befs_init_inodecache(void)
434{
435 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
436 sizeof(struct befs_inode_info), 0,
437 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
438 SLAB_ACCOUNT),
439 offsetof(struct befs_inode_info,
440 i_data.symlink),
441 sizeof_field(struct befs_inode_info,
442 i_data.symlink),
443 init_once);
444 if (befs_inode_cachep == NULL)
445 return -ENOMEM;
446
447 return 0;
448}
449
450/* Called at fs teardown.
451 *
452 * Taken from NFS implementation by Al Viro.
453 */
454static void
455befs_destroy_inodecache(void)
456{
457 /*
458 * Make sure all delayed rcu free inodes are flushed before we
459 * destroy cache.
460 */
461 rcu_barrier();
462 kmem_cache_destroy(befs_inode_cachep);
463}
464
465/*
466 * The inode of symbolic link is different to data stream.
467 * The data stream become link name. Unless the LONG_SYMLINK
468 * flag is set.
469 */
470static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
471{
472 struct inode *inode = folio->mapping->host;
473 struct super_block *sb = inode->i_sb;
474 struct befs_inode_info *befs_ino = BEFS_I(inode);
475 befs_data_stream *data = &befs_ino->i_data.ds;
476 befs_off_t len = data->size;
477 char *link = folio_address(folio);
478
479 if (len == 0 || len > PAGE_SIZE) {
480 befs_error(sb, "Long symlink with illegal length");
481 goto fail;
482 }
483 befs_debug(sb, "Follow long symlink");
484
485 if (befs_read_lsymlink(sb, data, link, len) != len) {
486 befs_error(sb, "Failed to read entire long symlink");
487 goto fail;
488 }
489 link[len - 1] = '\0';
490 folio_mark_uptodate(folio);
491 folio_unlock(folio);
492 return 0;
493fail:
494 folio_set_error(folio);
495 folio_unlock(folio);
496 return -EIO;
497}
498
499/*
500 * UTF-8 to NLS charset convert routine
501 *
502 * Uses uni2char() / char2uni() rather than the nls tables directly
503 */
504static int
505befs_utf2nls(struct super_block *sb, const char *in,
506 int in_len, char **out, int *out_len)
507{
508 struct nls_table *nls = BEFS_SB(sb)->nls;
509 int i, o;
510 unicode_t uni;
511 int unilen, utflen;
512 char *result;
513 /* The utf8->nls conversion won't make the final nls string bigger
514 * than the utf one, but if the string is pure ascii they'll have the
515 * same width and an extra char is needed to save the additional \0
516 */
517 int maxlen = in_len + 1;
518
519 befs_debug(sb, "---> %s", __func__);
520
521 if (!nls) {
522 befs_error(sb, "%s called with no NLS table loaded", __func__);
523 return -EINVAL;
524 }
525
526 *out = result = kmalloc(maxlen, GFP_NOFS);
527 if (!*out)
528 return -ENOMEM;
529
530 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
531
532 /* convert from UTF-8 to Unicode */
533 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
534 if (utflen < 0)
535 goto conv_err;
536
537 /* convert from Unicode to nls */
538 if (uni > MAX_WCHAR_T)
539 goto conv_err;
540 unilen = nls->uni2char(uni, &result[o], in_len - o);
541 if (unilen < 0)
542 goto conv_err;
543 }
544 result[o] = '\0';
545 *out_len = o;
546
547 befs_debug(sb, "<--- %s", __func__);
548
549 return o;
550
551conv_err:
552 befs_error(sb, "Name using character set %s contains a character that "
553 "cannot be converted to unicode.", nls->charset);
554 befs_debug(sb, "<--- %s", __func__);
555 kfree(result);
556 return -EILSEQ;
557}
558
559/**
560 * befs_nls2utf - Convert NLS string to utf8 encodeing
561 * @sb: Superblock
562 * @in: Input string buffer in NLS format
563 * @in_len: Length of input string in bytes
564 * @out: The output string in UTF-8 format
565 * @out_len: Length of the output buffer
566 *
567 * Converts input string @in, which is in the format of the loaded NLS map,
568 * into a utf8 string.
569 *
570 * The destination string @out is allocated by this function and the caller is
571 * responsible for freeing it with kfree()
572 *
573 * On return, *@out_len is the length of @out in bytes.
574 *
575 * On success, the return value is the number of utf8 characters written to
576 * the output buffer @out.
577 *
578 * On Failure, a negative number coresponding to the error code is returned.
579 */
580
581static int
582befs_nls2utf(struct super_block *sb, const char *in,
583 int in_len, char **out, int *out_len)
584{
585 struct nls_table *nls = BEFS_SB(sb)->nls;
586 int i, o;
587 wchar_t uni;
588 int unilen, utflen;
589 char *result;
590 /*
591 * There are nls characters that will translate to 3-chars-wide UTF-8
592 * characters, an additional byte is needed to save the final \0
593 * in special cases
594 */
595 int maxlen = (3 * in_len) + 1;
596
597 befs_debug(sb, "---> %s\n", __func__);
598
599 if (!nls) {
600 befs_error(sb, "%s called with no NLS table loaded.",
601 __func__);
602 return -EINVAL;
603 }
604
605 *out = result = kmalloc(maxlen, GFP_NOFS);
606 if (!*out) {
607 *out_len = 0;
608 return -ENOMEM;
609 }
610
611 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
612
613 /* convert from nls to unicode */
614 unilen = nls->char2uni(&in[i], in_len - i, &uni);
615 if (unilen < 0)
616 goto conv_err;
617
618 /* convert from unicode to UTF-8 */
619 utflen = utf32_to_utf8(uni, &result[o], 3);
620 if (utflen <= 0)
621 goto conv_err;
622 }
623
624 result[o] = '\0';
625 *out_len = o;
626
627 befs_debug(sb, "<--- %s", __func__);
628
629 return i;
630
631conv_err:
632 befs_error(sb, "Name using character set %s contains a character that "
633 "cannot be converted to unicode.", nls->charset);
634 befs_debug(sb, "<--- %s", __func__);
635 kfree(result);
636 return -EILSEQ;
637}
638
639static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
640 uint32_t generation)
641{
642 /* No need to handle i_generation */
643 return befs_iget(sb, ino);
644}
645
646/*
647 * Map a NFS file handle to a corresponding dentry
648 */
649static struct dentry *befs_fh_to_dentry(struct super_block *sb,
650 struct fid *fid, int fh_len, int fh_type)
651{
652 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
653 befs_nfs_get_inode);
654}
655
656/*
657 * Find the parent for a file specified by NFS handle
658 */
659static struct dentry *befs_fh_to_parent(struct super_block *sb,
660 struct fid *fid, int fh_len, int fh_type)
661{
662 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
663 befs_nfs_get_inode);
664}
665
666static struct dentry *befs_get_parent(struct dentry *child)
667{
668 struct inode *parent;
669 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
670
671 parent = befs_iget(child->d_sb,
672 (unsigned long)befs_ino->i_parent.start);
673 if (IS_ERR(parent))
674 return ERR_CAST(parent);
675
676 return d_obtain_alias(parent);
677}
678
679enum {
680 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
681};
682
683static const match_table_t befs_tokens = {
684 {Opt_uid, "uid=%d"},
685 {Opt_gid, "gid=%d"},
686 {Opt_charset, "iocharset=%s"},
687 {Opt_debug, "debug"},
688 {Opt_err, NULL}
689};
690
691static int
692parse_options(char *options, struct befs_mount_options *opts)
693{
694 char *p;
695 substring_t args[MAX_OPT_ARGS];
696 int option;
697 kuid_t uid;
698 kgid_t gid;
699
700 /* Initialize options */
701 opts->uid = GLOBAL_ROOT_UID;
702 opts->gid = GLOBAL_ROOT_GID;
703 opts->use_uid = 0;
704 opts->use_gid = 0;
705 opts->iocharset = NULL;
706 opts->debug = 0;
707
708 if (!options)
709 return 1;
710
711 while ((p = strsep(&options, ",")) != NULL) {
712 int token;
713
714 if (!*p)
715 continue;
716
717 token = match_token(p, befs_tokens, args);
718 switch (token) {
719 case Opt_uid:
720 if (match_int(&args[0], &option))
721 return 0;
722 uid = INVALID_UID;
723 if (option >= 0)
724 uid = make_kuid(current_user_ns(), option);
725 if (!uid_valid(uid)) {
726 pr_err("Invalid uid %d, "
727 "using default\n", option);
728 break;
729 }
730 opts->uid = uid;
731 opts->use_uid = 1;
732 break;
733 case Opt_gid:
734 if (match_int(&args[0], &option))
735 return 0;
736 gid = INVALID_GID;
737 if (option >= 0)
738 gid = make_kgid(current_user_ns(), option);
739 if (!gid_valid(gid)) {
740 pr_err("Invalid gid %d, "
741 "using default\n", option);
742 break;
743 }
744 opts->gid = gid;
745 opts->use_gid = 1;
746 break;
747 case Opt_charset:
748 kfree(opts->iocharset);
749 opts->iocharset = match_strdup(&args[0]);
750 if (!opts->iocharset) {
751 pr_err("allocation failure for "
752 "iocharset string\n");
753 return 0;
754 }
755 break;
756 case Opt_debug:
757 opts->debug = 1;
758 break;
759 default:
760 pr_err("Unrecognized mount option \"%s\" "
761 "or missing value\n", p);
762 return 0;
763 }
764 }
765 return 1;
766}
767
768static int befs_show_options(struct seq_file *m, struct dentry *root)
769{
770 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
771 struct befs_mount_options *opts = &befs_sb->mount_opts;
772
773 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
774 seq_printf(m, ",uid=%u",
775 from_kuid_munged(&init_user_ns, opts->uid));
776 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
777 seq_printf(m, ",gid=%u",
778 from_kgid_munged(&init_user_ns, opts->gid));
779 if (opts->iocharset)
780 seq_printf(m, ",charset=%s", opts->iocharset);
781 if (opts->debug)
782 seq_puts(m, ",debug");
783 return 0;
784}
785
786/* This function has the responsibiltiy of getting the
787 * filesystem ready for unmounting.
788 * Basically, we free everything that we allocated in
789 * befs_read_inode
790 */
791static void
792befs_put_super(struct super_block *sb)
793{
794 kfree(BEFS_SB(sb)->mount_opts.iocharset);
795 BEFS_SB(sb)->mount_opts.iocharset = NULL;
796 unload_nls(BEFS_SB(sb)->nls);
797 kfree(sb->s_fs_info);
798 sb->s_fs_info = NULL;
799}
800
801/* Allocate private field of the superblock, fill it.
802 *
803 * Finish filling the public superblock fields
804 * Make the root directory
805 * Load a set of NLS translations if needed.
806 */
807static int
808befs_fill_super(struct super_block *sb, void *data, int silent)
809{
810 struct buffer_head *bh;
811 struct befs_sb_info *befs_sb;
812 befs_super_block *disk_sb;
813 struct inode *root;
814 long ret = -EINVAL;
815 const unsigned long sb_block = 0;
816 const off_t x86_sb_off = 512;
817 int blocksize;
818
819 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
820 if (sb->s_fs_info == NULL)
821 goto unacquire_none;
822
823 befs_sb = BEFS_SB(sb);
824
825 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
826 if (!silent)
827 befs_error(sb, "cannot parse mount options");
828 goto unacquire_priv_sbp;
829 }
830
831 befs_debug(sb, "---> %s", __func__);
832
833 if (!sb_rdonly(sb)) {
834 befs_warning(sb,
835 "No write support. Marking filesystem read-only");
836 sb->s_flags |= SB_RDONLY;
837 }
838
839 /*
840 * Set dummy blocksize to read super block.
841 * Will be set to real fs blocksize later.
842 *
843 * Linux 2.4.10 and later refuse to read blocks smaller than
844 * the logical block size for the device. But we also need to read at
845 * least 1k to get the second 512 bytes of the volume.
846 */
847 blocksize = sb_min_blocksize(sb, 1024);
848 if (!blocksize) {
849 if (!silent)
850 befs_error(sb, "unable to set blocksize");
851 goto unacquire_priv_sbp;
852 }
853
854 bh = sb_bread(sb, sb_block);
855 if (!bh) {
856 if (!silent)
857 befs_error(sb, "unable to read superblock");
858 goto unacquire_priv_sbp;
859 }
860
861 /* account for offset of super block on x86 */
862 disk_sb = (befs_super_block *) bh->b_data;
863 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
864 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
865 befs_debug(sb, "Using PPC superblock location");
866 } else {
867 befs_debug(sb, "Using x86 superblock location");
868 disk_sb =
869 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
870 }
871
872 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
873 (befs_check_sb(sb) != BEFS_OK))
874 goto unacquire_bh;
875
876 befs_dump_super_block(sb, disk_sb);
877
878 brelse(bh);
879
880 if (befs_sb->num_blocks > ~((sector_t)0)) {
881 if (!silent)
882 befs_error(sb, "blocks count: %llu is larger than the host can use",
883 befs_sb->num_blocks);
884 goto unacquire_priv_sbp;
885 }
886
887 /*
888 * set up enough so that it can read an inode
889 * Fill in kernel superblock fields from private sb
890 */
891 sb->s_magic = BEFS_SUPER_MAGIC;
892 /* Set real blocksize of fs */
893 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
894 sb->s_op = &befs_sops;
895 sb->s_export_op = &befs_export_operations;
896 sb->s_time_min = 0;
897 sb->s_time_max = 0xffffffffffffll;
898 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
899 if (IS_ERR(root)) {
900 ret = PTR_ERR(root);
901 goto unacquire_priv_sbp;
902 }
903 sb->s_root = d_make_root(root);
904 if (!sb->s_root) {
905 if (!silent)
906 befs_error(sb, "get root inode failed");
907 goto unacquire_priv_sbp;
908 }
909
910 /* load nls library */
911 if (befs_sb->mount_opts.iocharset) {
912 befs_debug(sb, "Loading nls: %s",
913 befs_sb->mount_opts.iocharset);
914 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
915 if (!befs_sb->nls) {
916 befs_warning(sb, "Cannot load nls %s"
917 " loading default nls",
918 befs_sb->mount_opts.iocharset);
919 befs_sb->nls = load_nls_default();
920 }
921 /* load default nls if none is specified in mount options */
922 } else {
923 befs_debug(sb, "Loading default nls");
924 befs_sb->nls = load_nls_default();
925 }
926
927 return 0;
928
929unacquire_bh:
930 brelse(bh);
931
932unacquire_priv_sbp:
933 kfree(befs_sb->mount_opts.iocharset);
934 kfree(sb->s_fs_info);
935 sb->s_fs_info = NULL;
936
937unacquire_none:
938 return ret;
939}
940
941static int
942befs_remount(struct super_block *sb, int *flags, char *data)
943{
944 sync_filesystem(sb);
945 if (!(*flags & SB_RDONLY))
946 return -EINVAL;
947 return 0;
948}
949
950static int
951befs_statfs(struct dentry *dentry, struct kstatfs *buf)
952{
953 struct super_block *sb = dentry->d_sb;
954 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
955
956 befs_debug(sb, "---> %s", __func__);
957
958 buf->f_type = BEFS_SUPER_MAGIC;
959 buf->f_bsize = sb->s_blocksize;
960 buf->f_blocks = BEFS_SB(sb)->num_blocks;
961 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
962 buf->f_bavail = buf->f_bfree;
963 buf->f_files = 0; /* UNKNOWN */
964 buf->f_ffree = 0; /* UNKNOWN */
965 buf->f_fsid = u64_to_fsid(id);
966 buf->f_namelen = BEFS_NAME_LEN;
967
968 befs_debug(sb, "<--- %s", __func__);
969
970 return 0;
971}
972
973static struct dentry *
974befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
975 void *data)
976{
977 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
978}
979
980static struct file_system_type befs_fs_type = {
981 .owner = THIS_MODULE,
982 .name = "befs",
983 .mount = befs_mount,
984 .kill_sb = kill_block_super,
985 .fs_flags = FS_REQUIRES_DEV,
986};
987MODULE_ALIAS_FS("befs");
988
989static int __init
990init_befs_fs(void)
991{
992 int err;
993
994 pr_info("version: %s\n", BEFS_VERSION);
995
996 err = befs_init_inodecache();
997 if (err)
998 goto unacquire_none;
999
1000 err = register_filesystem(&befs_fs_type);
1001 if (err)
1002 goto unacquire_inodecache;
1003
1004 return 0;
1005
1006unacquire_inodecache:
1007 befs_destroy_inodecache();
1008
1009unacquire_none:
1010 return err;
1011}
1012
1013static void __exit
1014exit_befs_fs(void)
1015{
1016 befs_destroy_inodecache();
1017
1018 unregister_filesystem(&befs_fs_type);
1019}
1020
1021/*
1022 * Macros that typecheck the init and exit functions,
1023 * ensures that they are called at init and cleanup,
1024 * and eliminates warnings about unused functions.
1025 */
1026module_init(init_befs_fs)
1027module_exit(exit_befs_fs)