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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_readpage(struct file *file, struct page *page);
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_readpage(struct file *, struct page *);
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 .readpage = befs_readpage,
91 .bmap = befs_bmap,
92};
93
94static const struct address_space_operations befs_symlink_aops = {
95 .readpage = befs_symlink_readpage,
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 page 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
112befs_readpage(struct file *file, struct page *page)
113{
114 return block_read_full_page(page, befs_get_block);
115}
116
117static sector_t
118befs_bmap(struct address_space *mapping, sector_t block)
119{
120 return generic_block_bmap(mapping, block, befs_get_block);
121}
122
123/*
124 * Generic function to map a file position (block) to a
125 * disk offset (passed back in bh_result).
126 *
127 * Used by many higher level functions.
128 *
129 * Calls befs_fblock2brun() in datastream.c to do the real work.
130 */
131
132static int
133befs_get_block(struct inode *inode, sector_t block,
134 struct buffer_head *bh_result, int create)
135{
136 struct super_block *sb = inode->i_sb;
137 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
138 befs_block_run run = BAD_IADDR;
139 int res;
140 ulong disk_off;
141
142 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
143 (unsigned long)inode->i_ino, (long)block);
144 if (create) {
145 befs_error(sb, "befs_get_block() was asked to write to "
146 "block %ld in inode %lu", (long)block,
147 (unsigned long)inode->i_ino);
148 return -EPERM;
149 }
150
151 res = befs_fblock2brun(sb, ds, block, &run);
152 if (res != BEFS_OK) {
153 befs_error(sb,
154 "<--- %s for inode %lu, block %ld ERROR",
155 __func__, (unsigned long)inode->i_ino,
156 (long)block);
157 return -EFBIG;
158 }
159
160 disk_off = (ulong) iaddr2blockno(sb, &run);
161
162 map_bh(bh_result, inode->i_sb, disk_off);
163
164 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
165 __func__, (unsigned long)inode->i_ino, (long)block,
166 (unsigned long)disk_off);
167
168 return 0;
169}
170
171static struct dentry *
172befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
173{
174 struct inode *inode;
175 struct super_block *sb = dir->i_sb;
176 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
177 befs_off_t offset;
178 int ret;
179 int utfnamelen;
180 char *utfname;
181 const char *name = dentry->d_name.name;
182
183 befs_debug(sb, "---> %s name %pd inode %ld", __func__,
184 dentry, dir->i_ino);
185
186 /* Convert to UTF-8 */
187 if (BEFS_SB(sb)->nls) {
188 ret =
189 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
190 if (ret < 0) {
191 befs_debug(sb, "<--- %s ERROR", __func__);
192 return ERR_PTR(ret);
193 }
194 ret = befs_btree_find(sb, ds, utfname, &offset);
195 kfree(utfname);
196
197 } else {
198 ret = befs_btree_find(sb, ds, name, &offset);
199 }
200
201 if (ret == BEFS_BT_NOT_FOUND) {
202 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
203 inode = NULL;
204 } else if (ret != BEFS_OK || offset == 0) {
205 befs_error(sb, "<--- %s Error", __func__);
206 inode = ERR_PTR(-ENODATA);
207 } else {
208 inode = befs_iget(dir->i_sb, (ino_t) offset);
209 }
210 befs_debug(sb, "<--- %s", __func__);
211
212 return d_splice_alias(inode, dentry);
213}
214
215static int
216befs_readdir(struct file *file, struct dir_context *ctx)
217{
218 struct inode *inode = file_inode(file);
219 struct super_block *sb = inode->i_sb;
220 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
221 befs_off_t value;
222 int result;
223 size_t keysize;
224 char keybuf[BEFS_NAME_LEN + 1];
225
226 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
227 __func__, file, inode->i_ino, ctx->pos);
228
229 while (1) {
230 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
231 keybuf, &keysize, &value);
232
233 if (result == BEFS_ERR) {
234 befs_debug(sb, "<--- %s ERROR", __func__);
235 befs_error(sb, "IO error reading %pD (inode %lu)",
236 file, inode->i_ino);
237 return -EIO;
238
239 } else if (result == BEFS_BT_END) {
240 befs_debug(sb, "<--- %s END", __func__);
241 return 0;
242
243 } else if (result == BEFS_BT_EMPTY) {
244 befs_debug(sb, "<--- %s Empty directory", __func__);
245 return 0;
246 }
247
248 /* Convert to NLS */
249 if (BEFS_SB(sb)->nls) {
250 char *nlsname;
251 int nlsnamelen;
252
253 result =
254 befs_utf2nls(sb, keybuf, keysize, &nlsname,
255 &nlsnamelen);
256 if (result < 0) {
257 befs_debug(sb, "<--- %s ERROR", __func__);
258 return result;
259 }
260 if (!dir_emit(ctx, nlsname, nlsnamelen,
261 (ino_t) value, DT_UNKNOWN)) {
262 kfree(nlsname);
263 return 0;
264 }
265 kfree(nlsname);
266 } else {
267 if (!dir_emit(ctx, keybuf, keysize,
268 (ino_t) value, DT_UNKNOWN))
269 return 0;
270 }
271 ctx->pos++;
272 }
273}
274
275static struct inode *
276befs_alloc_inode(struct super_block *sb)
277{
278 struct befs_inode_info *bi;
279
280 bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
281 if (!bi)
282 return NULL;
283 return &bi->vfs_inode;
284}
285
286static void befs_free_inode(struct inode *inode)
287{
288 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
289}
290
291static void init_once(void *foo)
292{
293 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
294
295 inode_init_once(&bi->vfs_inode);
296}
297
298static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
299{
300 struct buffer_head *bh;
301 befs_inode *raw_inode;
302 struct befs_sb_info *befs_sb = BEFS_SB(sb);
303 struct befs_inode_info *befs_ino;
304 struct inode *inode;
305
306 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
307
308 inode = iget_locked(sb, ino);
309 if (!inode)
310 return ERR_PTR(-ENOMEM);
311 if (!(inode->i_state & I_NEW))
312 return inode;
313
314 befs_ino = BEFS_I(inode);
315
316 /* convert from vfs's inode number to befs's inode number */
317 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
318
319 befs_debug(sb, " real inode number [%u, %hu, %hu]",
320 befs_ino->i_inode_num.allocation_group,
321 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
322
323 bh = sb_bread(sb, inode->i_ino);
324 if (!bh) {
325 befs_error(sb, "unable to read inode block - "
326 "inode = %lu", inode->i_ino);
327 goto unacquire_none;
328 }
329
330 raw_inode = (befs_inode *) bh->b_data;
331
332 befs_dump_inode(sb, raw_inode);
333
334 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
335 befs_error(sb, "Bad inode: %lu", inode->i_ino);
336 goto unacquire_bh;
337 }
338
339 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
340
341 /*
342 * set uid and gid. But since current BeOS is single user OS, so
343 * you can change by "uid" or "gid" options.
344 */
345
346 inode->i_uid = befs_sb->mount_opts.use_uid ?
347 befs_sb->mount_opts.uid :
348 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
349 inode->i_gid = befs_sb->mount_opts.use_gid ?
350 befs_sb->mount_opts.gid :
351 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
352
353 set_nlink(inode, 1);
354
355 /*
356 * BEFS's time is 64 bits, but current VFS is 32 bits...
357 * BEFS don't have access time. Nor inode change time. VFS
358 * doesn't have creation time.
359 * Also, the lower 16 bits of the last_modified_time and
360 * create_time are just a counter to help ensure uniqueness
361 * for indexing purposes. (PFD, page 54)
362 */
363
364 inode->i_mtime.tv_sec =
365 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
366 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
367 inode->i_ctime = inode->i_mtime;
368 inode->i_atime = inode->i_mtime;
369
370 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
371 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
372 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
373 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
374
375 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
376 inode->i_size = 0;
377 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
378 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
379 BEFS_SYMLINK_LEN);
380 } else {
381 int num_blks;
382
383 befs_ino->i_data.ds =
384 fsds_to_cpu(sb, &raw_inode->data.datastream);
385
386 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
387 inode->i_blocks =
388 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
389 inode->i_size = befs_ino->i_data.ds.size;
390 }
391
392 inode->i_mapping->a_ops = &befs_aops;
393
394 if (S_ISREG(inode->i_mode)) {
395 inode->i_fop = &generic_ro_fops;
396 } else if (S_ISDIR(inode->i_mode)) {
397 inode->i_op = &befs_dir_inode_operations;
398 inode->i_fop = &befs_dir_operations;
399 } else if (S_ISLNK(inode->i_mode)) {
400 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
401 inode->i_op = &page_symlink_inode_operations;
402 inode_nohighmem(inode);
403 inode->i_mapping->a_ops = &befs_symlink_aops;
404 } else {
405 inode->i_link = befs_ino->i_data.symlink;
406 inode->i_op = &simple_symlink_inode_operations;
407 }
408 } else {
409 befs_error(sb, "Inode %lu is not a regular file, "
410 "directory or symlink. THAT IS WRONG! BeFS has no "
411 "on disk special files", inode->i_ino);
412 goto unacquire_bh;
413 }
414
415 brelse(bh);
416 befs_debug(sb, "<--- %s", __func__);
417 unlock_new_inode(inode);
418 return inode;
419
420unacquire_bh:
421 brelse(bh);
422
423unacquire_none:
424 iget_failed(inode);
425 befs_debug(sb, "<--- %s - Bad inode", __func__);
426 return ERR_PTR(-EIO);
427}
428
429/* Initialize the inode cache. Called at fs setup.
430 *
431 * Taken from NFS implementation by Al Viro.
432 */
433static int __init
434befs_init_inodecache(void)
435{
436 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
437 sizeof(struct befs_inode_info), 0,
438 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
439 SLAB_ACCOUNT),
440 offsetof(struct befs_inode_info,
441 i_data.symlink),
442 sizeof_field(struct befs_inode_info,
443 i_data.symlink),
444 init_once);
445 if (befs_inode_cachep == NULL)
446 return -ENOMEM;
447
448 return 0;
449}
450
451/* Called at fs teardown.
452 *
453 * Taken from NFS implementation by Al Viro.
454 */
455static void
456befs_destroy_inodecache(void)
457{
458 /*
459 * Make sure all delayed rcu free inodes are flushed before we
460 * destroy cache.
461 */
462 rcu_barrier();
463 kmem_cache_destroy(befs_inode_cachep);
464}
465
466/*
467 * The inode of symbolic link is different to data stream.
468 * The data stream become link name. Unless the LONG_SYMLINK
469 * flag is set.
470 */
471static int befs_symlink_readpage(struct file *unused, struct page *page)
472{
473 struct inode *inode = page->mapping->host;
474 struct super_block *sb = inode->i_sb;
475 struct befs_inode_info *befs_ino = BEFS_I(inode);
476 befs_data_stream *data = &befs_ino->i_data.ds;
477 befs_off_t len = data->size;
478 char *link = page_address(page);
479
480 if (len == 0 || len > PAGE_SIZE) {
481 befs_error(sb, "Long symlink with illegal length");
482 goto fail;
483 }
484 befs_debug(sb, "Follow long symlink");
485
486 if (befs_read_lsymlink(sb, data, link, len) != len) {
487 befs_error(sb, "Failed to read entire long symlink");
488 goto fail;
489 }
490 link[len - 1] = '\0';
491 SetPageUptodate(page);
492 unlock_page(page);
493 return 0;
494fail:
495 SetPageError(page);
496 unlock_page(page);
497 return -EIO;
498}
499
500/*
501 * UTF-8 to NLS charset convert routine
502 *
503 * Uses uni2char() / char2uni() rather than the nls tables directly
504 */
505static int
506befs_utf2nls(struct super_block *sb, const char *in,
507 int in_len, char **out, int *out_len)
508{
509 struct nls_table *nls = BEFS_SB(sb)->nls;
510 int i, o;
511 unicode_t uni;
512 int unilen, utflen;
513 char *result;
514 /* The utf8->nls conversion won't make the final nls string bigger
515 * than the utf one, but if the string is pure ascii they'll have the
516 * same width and an extra char is needed to save the additional \0
517 */
518 int maxlen = in_len + 1;
519
520 befs_debug(sb, "---> %s", __func__);
521
522 if (!nls) {
523 befs_error(sb, "%s called with no NLS table loaded", __func__);
524 return -EINVAL;
525 }
526
527 *out = result = kmalloc(maxlen, GFP_NOFS);
528 if (!*out)
529 return -ENOMEM;
530
531 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
532
533 /* convert from UTF-8 to Unicode */
534 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
535 if (utflen < 0)
536 goto conv_err;
537
538 /* convert from Unicode to nls */
539 if (uni > MAX_WCHAR_T)
540 goto conv_err;
541 unilen = nls->uni2char(uni, &result[o], in_len - o);
542 if (unilen < 0)
543 goto conv_err;
544 }
545 result[o] = '\0';
546 *out_len = o;
547
548 befs_debug(sb, "<--- %s", __func__);
549
550 return o;
551
552conv_err:
553 befs_error(sb, "Name using character set %s contains a character that "
554 "cannot be converted to unicode.", nls->charset);
555 befs_debug(sb, "<--- %s", __func__);
556 kfree(result);
557 return -EILSEQ;
558}
559
560/**
561 * befs_nls2utf - Convert NLS string to utf8 encodeing
562 * @sb: Superblock
563 * @in: Input string buffer in NLS format
564 * @in_len: Length of input string in bytes
565 * @out: The output string in UTF-8 format
566 * @out_len: Length of the output buffer
567 *
568 * Converts input string @in, which is in the format of the loaded NLS map,
569 * into a utf8 string.
570 *
571 * The destination string @out is allocated by this function and the caller is
572 * responsible for freeing it with kfree()
573 *
574 * On return, *@out_len is the length of @out in bytes.
575 *
576 * On success, the return value is the number of utf8 characters written to
577 * the output buffer @out.
578 *
579 * On Failure, a negative number coresponding to the error code is returned.
580 */
581
582static int
583befs_nls2utf(struct super_block *sb, const char *in,
584 int in_len, char **out, int *out_len)
585{
586 struct nls_table *nls = BEFS_SB(sb)->nls;
587 int i, o;
588 wchar_t uni;
589 int unilen, utflen;
590 char *result;
591 /*
592 * There are nls characters that will translate to 3-chars-wide UTF-8
593 * characters, an additional byte is needed to save the final \0
594 * in special cases
595 */
596 int maxlen = (3 * in_len) + 1;
597
598 befs_debug(sb, "---> %s\n", __func__);
599
600 if (!nls) {
601 befs_error(sb, "%s called with no NLS table loaded.",
602 __func__);
603 return -EINVAL;
604 }
605
606 *out = result = kmalloc(maxlen, GFP_NOFS);
607 if (!*out) {
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
632conv_err:
633 befs_error(sb, "Name using character set %s contains a character that "
634 "cannot be converted to unicode.", nls->charset);
635 befs_debug(sb, "<--- %s", __func__);
636 kfree(result);
637 return -EILSEQ;
638}
639
640static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
641 uint32_t generation)
642{
643 /* No need to handle i_generation */
644 return befs_iget(sb, ino);
645}
646
647/*
648 * Map a NFS file handle to a corresponding dentry
649 */
650static struct dentry *befs_fh_to_dentry(struct super_block *sb,
651 struct fid *fid, int fh_len, int fh_type)
652{
653 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
654 befs_nfs_get_inode);
655}
656
657/*
658 * Find the parent for a file specified by NFS handle
659 */
660static struct dentry *befs_fh_to_parent(struct super_block *sb,
661 struct fid *fid, int fh_len, int fh_type)
662{
663 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
664 befs_nfs_get_inode);
665}
666
667static struct dentry *befs_get_parent(struct dentry *child)
668{
669 struct inode *parent;
670 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
671
672 parent = befs_iget(child->d_sb,
673 (unsigned long)befs_ino->i_parent.start);
674 if (IS_ERR(parent))
675 return ERR_CAST(parent);
676
677 return d_obtain_alias(parent);
678}
679
680enum {
681 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
682};
683
684static const match_table_t befs_tokens = {
685 {Opt_uid, "uid=%d"},
686 {Opt_gid, "gid=%d"},
687 {Opt_charset, "iocharset=%s"},
688 {Opt_debug, "debug"},
689 {Opt_err, NULL}
690};
691
692static int
693parse_options(char *options, struct befs_mount_options *opts)
694{
695 char *p;
696 substring_t args[MAX_OPT_ARGS];
697 int option;
698 kuid_t uid;
699 kgid_t gid;
700
701 /* Initialize options */
702 opts->uid = GLOBAL_ROOT_UID;
703 opts->gid = GLOBAL_ROOT_GID;
704 opts->use_uid = 0;
705 opts->use_gid = 0;
706 opts->iocharset = NULL;
707 opts->debug = 0;
708
709 if (!options)
710 return 1;
711
712 while ((p = strsep(&options, ",")) != NULL) {
713 int token;
714
715 if (!*p)
716 continue;
717
718 token = match_token(p, befs_tokens, args);
719 switch (token) {
720 case Opt_uid:
721 if (match_int(&args[0], &option))
722 return 0;
723 uid = INVALID_UID;
724 if (option >= 0)
725 uid = make_kuid(current_user_ns(), option);
726 if (!uid_valid(uid)) {
727 pr_err("Invalid uid %d, "
728 "using default\n", option);
729 break;
730 }
731 opts->uid = uid;
732 opts->use_uid = 1;
733 break;
734 case Opt_gid:
735 if (match_int(&args[0], &option))
736 return 0;
737 gid = INVALID_GID;
738 if (option >= 0)
739 gid = make_kgid(current_user_ns(), option);
740 if (!gid_valid(gid)) {
741 pr_err("Invalid gid %d, "
742 "using default\n", option);
743 break;
744 }
745 opts->gid = gid;
746 opts->use_gid = 1;
747 break;
748 case Opt_charset:
749 kfree(opts->iocharset);
750 opts->iocharset = match_strdup(&args[0]);
751 if (!opts->iocharset) {
752 pr_err("allocation failure for "
753 "iocharset string\n");
754 return 0;
755 }
756 break;
757 case Opt_debug:
758 opts->debug = 1;
759 break;
760 default:
761 pr_err("Unrecognized mount option \"%s\" "
762 "or missing value\n", p);
763 return 0;
764 }
765 }
766 return 1;
767}
768
769static int befs_show_options(struct seq_file *m, struct dentry *root)
770{
771 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
772 struct befs_mount_options *opts = &befs_sb->mount_opts;
773
774 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
775 seq_printf(m, ",uid=%u",
776 from_kuid_munged(&init_user_ns, opts->uid));
777 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
778 seq_printf(m, ",gid=%u",
779 from_kgid_munged(&init_user_ns, opts->gid));
780 if (opts->iocharset)
781 seq_printf(m, ",charset=%s", opts->iocharset);
782 if (opts->debug)
783 seq_puts(m, ",debug");
784 return 0;
785}
786
787/* This function has the responsibiltiy of getting the
788 * filesystem ready for unmounting.
789 * Basically, we free everything that we allocated in
790 * befs_read_inode
791 */
792static void
793befs_put_super(struct super_block *sb)
794{
795 kfree(BEFS_SB(sb)->mount_opts.iocharset);
796 BEFS_SB(sb)->mount_opts.iocharset = NULL;
797 unload_nls(BEFS_SB(sb)->nls);
798 kfree(sb->s_fs_info);
799 sb->s_fs_info = NULL;
800}
801
802/* Allocate private field of the superblock, fill it.
803 *
804 * Finish filling the public superblock fields
805 * Make the root directory
806 * Load a set of NLS translations if needed.
807 */
808static int
809befs_fill_super(struct super_block *sb, void *data, int silent)
810{
811 struct buffer_head *bh;
812 struct befs_sb_info *befs_sb;
813 befs_super_block *disk_sb;
814 struct inode *root;
815 long ret = -EINVAL;
816 const unsigned long sb_block = 0;
817 const off_t x86_sb_off = 512;
818 int blocksize;
819
820 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
821 if (sb->s_fs_info == NULL)
822 goto unacquire_none;
823
824 befs_sb = BEFS_SB(sb);
825
826 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
827 if (!silent)
828 befs_error(sb, "cannot parse mount options");
829 goto unacquire_priv_sbp;
830 }
831
832 befs_debug(sb, "---> %s", __func__);
833
834 if (!sb_rdonly(sb)) {
835 befs_warning(sb,
836 "No write support. Marking filesystem read-only");
837 sb->s_flags |= SB_RDONLY;
838 }
839
840 /*
841 * Set dummy blocksize to read super block.
842 * Will be set to real fs blocksize later.
843 *
844 * Linux 2.4.10 and later refuse to read blocks smaller than
845 * the logical block size for the device. But we also need to read at
846 * least 1k to get the second 512 bytes of the volume.
847 */
848 blocksize = sb_min_blocksize(sb, 1024);
849 if (!blocksize) {
850 if (!silent)
851 befs_error(sb, "unable to set blocksize");
852 goto unacquire_priv_sbp;
853 }
854
855 bh = sb_bread(sb, sb_block);
856 if (!bh) {
857 if (!silent)
858 befs_error(sb, "unable to read superblock");
859 goto unacquire_priv_sbp;
860 }
861
862 /* account for offset of super block on x86 */
863 disk_sb = (befs_super_block *) bh->b_data;
864 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
865 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
866 befs_debug(sb, "Using PPC superblock location");
867 } else {
868 befs_debug(sb, "Using x86 superblock location");
869 disk_sb =
870 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
871 }
872
873 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
874 (befs_check_sb(sb) != BEFS_OK))
875 goto unacquire_bh;
876
877 befs_dump_super_block(sb, disk_sb);
878
879 brelse(bh);
880
881 if (befs_sb->num_blocks > ~((sector_t)0)) {
882 if (!silent)
883 befs_error(sb, "blocks count: %llu is larger than the host can use",
884 befs_sb->num_blocks);
885 goto unacquire_priv_sbp;
886 }
887
888 /*
889 * set up enough so that it can read an inode
890 * Fill in kernel superblock fields from private sb
891 */
892 sb->s_magic = BEFS_SUPER_MAGIC;
893 /* Set real blocksize of fs */
894 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
895 sb->s_op = &befs_sops;
896 sb->s_export_op = &befs_export_operations;
897 sb->s_time_min = 0;
898 sb->s_time_max = 0xffffffffffffll;
899 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
900 if (IS_ERR(root)) {
901 ret = PTR_ERR(root);
902 goto unacquire_priv_sbp;
903 }
904 sb->s_root = d_make_root(root);
905 if (!sb->s_root) {
906 if (!silent)
907 befs_error(sb, "get root inode failed");
908 goto unacquire_priv_sbp;
909 }
910
911 /* load nls library */
912 if (befs_sb->mount_opts.iocharset) {
913 befs_debug(sb, "Loading nls: %s",
914 befs_sb->mount_opts.iocharset);
915 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
916 if (!befs_sb->nls) {
917 befs_warning(sb, "Cannot load nls %s"
918 " loading default nls",
919 befs_sb->mount_opts.iocharset);
920 befs_sb->nls = load_nls_default();
921 }
922 /* load default nls if none is specified in mount options */
923 } else {
924 befs_debug(sb, "Loading default nls");
925 befs_sb->nls = load_nls_default();
926 }
927
928 return 0;
929
930unacquire_bh:
931 brelse(bh);
932
933unacquire_priv_sbp:
934 kfree(befs_sb->mount_opts.iocharset);
935 kfree(sb->s_fs_info);
936 sb->s_fs_info = NULL;
937
938unacquire_none:
939 return ret;
940}
941
942static int
943befs_remount(struct super_block *sb, int *flags, char *data)
944{
945 sync_filesystem(sb);
946 if (!(*flags & SB_RDONLY))
947 return -EINVAL;
948 return 0;
949}
950
951static int
952befs_statfs(struct dentry *dentry, struct kstatfs *buf)
953{
954 struct super_block *sb = dentry->d_sb;
955 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
956
957 befs_debug(sb, "---> %s", __func__);
958
959 buf->f_type = BEFS_SUPER_MAGIC;
960 buf->f_bsize = sb->s_blocksize;
961 buf->f_blocks = BEFS_SB(sb)->num_blocks;
962 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
963 buf->f_bavail = buf->f_bfree;
964 buf->f_files = 0; /* UNKNOWN */
965 buf->f_ffree = 0; /* UNKNOWN */
966 buf->f_fsid = u64_to_fsid(id);
967 buf->f_namelen = BEFS_NAME_LEN;
968
969 befs_debug(sb, "<--- %s", __func__);
970
971 return 0;
972}
973
974static struct dentry *
975befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
976 void *data)
977{
978 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
979}
980
981static struct file_system_type befs_fs_type = {
982 .owner = THIS_MODULE,
983 .name = "befs",
984 .mount = befs_mount,
985 .kill_sb = kill_block_super,
986 .fs_flags = FS_REQUIRES_DEV,
987};
988MODULE_ALIAS_FS("befs");
989
990static int __init
991init_befs_fs(void)
992{
993 int err;
994
995 pr_info("version: %s\n", BEFS_VERSION);
996
997 err = befs_init_inodecache();
998 if (err)
999 goto unacquire_none;
1000
1001 err = register_filesystem(&befs_fs_type);
1002 if (err)
1003 goto unacquire_inodecache;
1004
1005 return 0;
1006
1007unacquire_inodecache:
1008 befs_destroy_inodecache();
1009
1010unacquire_none:
1011 return err;
1012}
1013
1014static void __exit
1015exit_befs_fs(void)
1016{
1017 befs_destroy_inodecache();
1018
1019 unregister_filesystem(&befs_fs_type);
1020}
1021
1022/*
1023 * Macros that typecheck the init and exit functions,
1024 * ensures that they are called at init and cleanup,
1025 * and eliminates warnings about unused functions.
1026 */
1027module_init(init_befs_fs)
1028module_exit(exit_befs_fs)