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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 void *befs_follow_link(struct dentry *, struct nameidata *);
46static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
47static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
48 char **out, int *out_len);
49static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
50 char **out, int *out_len);
51static void befs_put_super(struct super_block *);
52static int befs_remount(struct super_block *, int *, char *);
53static int befs_statfs(struct dentry *, struct kstatfs *);
54static int parse_options(char *, befs_mount_options *);
55
56static const struct super_operations befs_sops = {
57 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
58 .destroy_inode = befs_destroy_inode, /* deallocate an inode */
59 .put_super = befs_put_super, /* uninit super */
60 .statfs = befs_statfs, /* statfs */
61 .remount_fs = befs_remount,
62 .show_options = generic_show_options,
63};
64
65/* slab cache for befs_inode_info objects */
66static struct kmem_cache *befs_inode_cachep;
67
68static const struct file_operations befs_dir_operations = {
69 .read = generic_read_dir,
70 .iterate = befs_readdir,
71 .llseek = generic_file_llseek,
72};
73
74static const struct inode_operations befs_dir_inode_operations = {
75 .lookup = befs_lookup,
76};
77
78static const struct address_space_operations befs_aops = {
79 .readpage = befs_readpage,
80 .bmap = befs_bmap,
81};
82
83static const struct inode_operations befs_fast_symlink_inode_operations = {
84 .readlink = generic_readlink,
85 .follow_link = befs_fast_follow_link,
86};
87
88static const struct inode_operations befs_symlink_inode_operations = {
89 .readlink = generic_readlink,
90 .follow_link = befs_follow_link,
91 .put_link = kfree_put_link,
92};
93
94/*
95 * Called by generic_file_read() to read a page of data
96 *
97 * In turn, simply calls a generic block read function and
98 * passes it the address of befs_get_block, for mapping file
99 * positions to disk blocks.
100 */
101static int
102befs_readpage(struct file *file, struct page *page)
103{
104 return block_read_full_page(page, befs_get_block);
105}
106
107static sector_t
108befs_bmap(struct address_space *mapping, sector_t block)
109{
110 return generic_block_bmap(mapping, block, befs_get_block);
111}
112
113/*
114 * Generic function to map a file position (block) to a
115 * disk offset (passed back in bh_result).
116 *
117 * Used by many higher level functions.
118 *
119 * Calls befs_fblock2brun() in datastream.c to do the real work.
120 *
121 * -WD 10-26-01
122 */
123
124static int
125befs_get_block(struct inode *inode, sector_t block,
126 struct buffer_head *bh_result, int create)
127{
128 struct super_block *sb = inode->i_sb;
129 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
130 befs_block_run run = BAD_IADDR;
131 int res = 0;
132 ulong disk_off;
133
134 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
135 (unsigned long)inode->i_ino, (long)block);
136
137 if (block < 0) {
138 befs_error(sb, "befs_get_block() was asked for a block "
139 "number less than zero: block %ld in inode %lu",
140 (long)block, (unsigned long)inode->i_ino);
141 return -EIO;
142 }
143
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 = NULL;
175 struct super_block *sb = dir->i_sb;
176 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 %s inode %ld", __func__,
184 dentry->d_name.name, 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, dentry->d_name.name, &offset);
199 }
200
201 if (ret == BEFS_BT_NOT_FOUND) {
202 befs_debug(sb, "<--- %s %s not found", __func__,
203 dentry->d_name.name);
204 return ERR_PTR(-ENOENT);
205
206 } else if (ret != BEFS_OK || offset == 0) {
207 befs_warning(sb, "<--- %s Error", __func__);
208 return ERR_PTR(-ENODATA);
209 }
210
211 inode = befs_iget(dir->i_sb, (ino_t) offset);
212 if (IS_ERR(inode))
213 return ERR_CAST(inode);
214
215 d_add(dentry, inode);
216
217 befs_debug(sb, "<--- %s", __func__);
218
219 return NULL;
220}
221
222static int
223befs_readdir(struct file *file, struct dir_context *ctx)
224{
225 struct inode *inode = file_inode(file);
226 struct super_block *sb = inode->i_sb;
227 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
228 befs_off_t value;
229 int result;
230 size_t keysize;
231 unsigned char d_type;
232 char keybuf[BEFS_NAME_LEN + 1];
233 const char *dirname = file->f_path.dentry->d_name.name;
234
235 befs_debug(sb, "---> %s name %s, inode %ld, ctx->pos %lld",
236 __func__, dirname, inode->i_ino, ctx->pos);
237
238more:
239 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
240 keybuf, &keysize, &value);
241
242 if (result == BEFS_ERR) {
243 befs_debug(sb, "<--- %s ERROR", __func__);
244 befs_error(sb, "IO error reading %s (inode %lu)",
245 dirname, inode->i_ino);
246 return -EIO;
247
248 } else if (result == BEFS_BT_END) {
249 befs_debug(sb, "<--- %s END", __func__);
250 return 0;
251
252 } else if (result == BEFS_BT_EMPTY) {
253 befs_debug(sb, "<--- %s Empty directory", __func__);
254 return 0;
255 }
256
257 d_type = DT_UNKNOWN;
258
259 /* Convert to NLS */
260 if (BEFS_SB(sb)->nls) {
261 char *nlsname;
262 int nlsnamelen;
263 result =
264 befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
265 if (result < 0) {
266 befs_debug(sb, "<--- %s ERROR", __func__);
267 return result;
268 }
269 if (!dir_emit(ctx, nlsname, nlsnamelen,
270 (ino_t) value, d_type)) {
271 kfree(nlsname);
272 return 0;
273 }
274 kfree(nlsname);
275 } else {
276 if (!dir_emit(ctx, keybuf, keysize,
277 (ino_t) value, d_type))
278 return 0;
279 }
280 ctx->pos++;
281 goto more;
282
283 befs_debug(sb, "<--- %s pos %lld", __func__, ctx->pos);
284
285 return 0;
286}
287
288static struct inode *
289befs_alloc_inode(struct super_block *sb)
290{
291 struct befs_inode_info *bi;
292 bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
293 GFP_KERNEL);
294 if (!bi)
295 return NULL;
296 return &bi->vfs_inode;
297}
298
299static void befs_i_callback(struct rcu_head *head)
300{
301 struct inode *inode = container_of(head, struct inode, i_rcu);
302 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
303}
304
305static void befs_destroy_inode(struct inode *inode)
306{
307 call_rcu(&inode->i_rcu, befs_i_callback);
308}
309
310static void init_once(void *foo)
311{
312 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
313
314 inode_init_once(&bi->vfs_inode);
315}
316
317static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
318{
319 struct buffer_head *bh = NULL;
320 befs_inode *raw_inode = NULL;
321
322 befs_sb_info *befs_sb = BEFS_SB(sb);
323 befs_inode_info *befs_ino = NULL;
324 struct inode *inode;
325 long ret = -EIO;
326
327 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
328
329 inode = iget_locked(sb, ino);
330 if (!inode)
331 return ERR_PTR(-ENOMEM);
332 if (!(inode->i_state & I_NEW))
333 return inode;
334
335 befs_ino = BEFS_I(inode);
336
337 /* convert from vfs's inode number to befs's inode number */
338 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
339
340 befs_debug(sb, " real inode number [%u, %hu, %hu]",
341 befs_ino->i_inode_num.allocation_group,
342 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
343
344 bh = befs_bread(sb, inode->i_ino);
345 if (!bh) {
346 befs_error(sb, "unable to read inode block - "
347 "inode = %lu", inode->i_ino);
348 goto unacquire_none;
349 }
350
351 raw_inode = (befs_inode *) bh->b_data;
352
353 befs_dump_inode(sb, raw_inode);
354
355 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
356 befs_error(sb, "Bad inode: %lu", inode->i_ino);
357 goto unacquire_bh;
358 }
359
360 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
361
362 /*
363 * set uid and gid. But since current BeOS is single user OS, so
364 * you can change by "uid" or "gid" options.
365 */
366
367 inode->i_uid = befs_sb->mount_opts.use_uid ?
368 befs_sb->mount_opts.uid :
369 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
370 inode->i_gid = befs_sb->mount_opts.use_gid ?
371 befs_sb->mount_opts.gid :
372 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
373
374 set_nlink(inode, 1);
375
376 /*
377 * BEFS's time is 64 bits, but current VFS is 32 bits...
378 * BEFS don't have access time. Nor inode change time. VFS
379 * doesn't have creation time.
380 * Also, the lower 16 bits of the last_modified_time and
381 * create_time are just a counter to help ensure uniqueness
382 * for indexing purposes. (PFD, page 54)
383 */
384
385 inode->i_mtime.tv_sec =
386 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
387 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
388 inode->i_ctime = inode->i_mtime;
389 inode->i_atime = inode->i_mtime;
390
391 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
392 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
393 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
394 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
395
396 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
397 inode->i_size = 0;
398 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
399 strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
400 BEFS_SYMLINK_LEN - 1);
401 befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
402 } else {
403 int num_blks;
404
405 befs_ino->i_data.ds =
406 fsds_to_cpu(sb, &raw_inode->data.datastream);
407
408 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
409 inode->i_blocks =
410 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
411 inode->i_size = befs_ino->i_data.ds.size;
412 }
413
414 inode->i_mapping->a_ops = &befs_aops;
415
416 if (S_ISREG(inode->i_mode)) {
417 inode->i_fop = &generic_ro_fops;
418 } else if (S_ISDIR(inode->i_mode)) {
419 inode->i_op = &befs_dir_inode_operations;
420 inode->i_fop = &befs_dir_operations;
421 } else if (S_ISLNK(inode->i_mode)) {
422 if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
423 inode->i_op = &befs_symlink_inode_operations;
424 else
425 inode->i_op = &befs_fast_symlink_inode_operations;
426 } else {
427 befs_error(sb, "Inode %lu is not a regular file, "
428 "directory or symlink. THAT IS WRONG! BeFS has no "
429 "on disk special files", inode->i_ino);
430 goto unacquire_bh;
431 }
432
433 brelse(bh);
434 befs_debug(sb, "<--- %s", __func__);
435 unlock_new_inode(inode);
436 return inode;
437
438 unacquire_bh:
439 brelse(bh);
440
441 unacquire_none:
442 iget_failed(inode);
443 befs_debug(sb, "<--- %s - Bad inode", __func__);
444 return ERR_PTR(ret);
445}
446
447/* Initialize the inode cache. Called at fs setup.
448 *
449 * Taken from NFS implementation by Al Viro.
450 */
451static int __init
452befs_init_inodecache(void)
453{
454 befs_inode_cachep = kmem_cache_create("befs_inode_cache",
455 sizeof (struct befs_inode_info),
456 0, (SLAB_RECLAIM_ACCOUNT|
457 SLAB_MEM_SPREAD),
458 init_once);
459 if (befs_inode_cachep == NULL) {
460 pr_err("%s: Couldn't initialize inode slabcache\n", __func__);
461 return -ENOMEM;
462 }
463 return 0;
464}
465
466/* Called at fs teardown.
467 *
468 * Taken from NFS implementation by Al Viro.
469 */
470static void
471befs_destroy_inodecache(void)
472{
473 /*
474 * Make sure all delayed rcu free inodes are flushed before we
475 * destroy cache.
476 */
477 rcu_barrier();
478 kmem_cache_destroy(befs_inode_cachep);
479}
480
481/*
482 * The inode of symbolic link is different to data stream.
483 * The data stream become link name. Unless the LONG_SYMLINK
484 * flag is set.
485 */
486static void *
487befs_follow_link(struct dentry *dentry, struct nameidata *nd)
488{
489 struct super_block *sb = dentry->d_sb;
490 befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
491 befs_data_stream *data = &befs_ino->i_data.ds;
492 befs_off_t len = data->size;
493 char *link;
494
495 if (len == 0) {
496 befs_error(sb, "Long symlink with illegal length");
497 link = ERR_PTR(-EIO);
498 } else {
499 befs_debug(sb, "Follow long symlink");
500
501 link = kmalloc(len, GFP_NOFS);
502 if (!link) {
503 link = ERR_PTR(-ENOMEM);
504 } else if (befs_read_lsymlink(sb, data, link, len) != len) {
505 kfree(link);
506 befs_error(sb, "Failed to read entire long symlink");
507 link = ERR_PTR(-EIO);
508 } else {
509 link[len - 1] = '\0';
510 }
511 }
512 nd_set_link(nd, link);
513 return NULL;
514}
515
516
517static void *
518befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
519{
520 befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
521 nd_set_link(nd, befs_ino->i_data.symlink);
522 return NULL;
523}
524
525/*
526 * UTF-8 to NLS charset convert routine
527 *
528 *
529 * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
530 * the nls tables directly
531 */
532
533static int
534befs_utf2nls(struct super_block *sb, const char *in,
535 int in_len, char **out, int *out_len)
536{
537 struct nls_table *nls = BEFS_SB(sb)->nls;
538 int i, o;
539 unicode_t uni;
540 int unilen, utflen;
541 char *result;
542 /* The utf8->nls conversion won't make the final nls string bigger
543 * than the utf one, but if the string is pure ascii they'll have the
544 * same width and an extra char is needed to save the additional \0
545 */
546 int maxlen = in_len + 1;
547
548 befs_debug(sb, "---> %s", __func__);
549
550 if (!nls) {
551 befs_error(sb, "%s called with no NLS table loaded", __func__);
552 return -EINVAL;
553 }
554
555 *out = result = kmalloc(maxlen, GFP_NOFS);
556 if (!*out) {
557 befs_error(sb, "%s cannot allocate memory", __func__);
558 *out_len = 0;
559 return -ENOMEM;
560 }
561
562 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
563
564 /* convert from UTF-8 to Unicode */
565 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
566 if (utflen < 0)
567 goto conv_err;
568
569 /* convert from Unicode to nls */
570 if (uni > MAX_WCHAR_T)
571 goto conv_err;
572 unilen = nls->uni2char(uni, &result[o], in_len - o);
573 if (unilen < 0)
574 goto conv_err;
575 }
576 result[o] = '\0';
577 *out_len = o;
578
579 befs_debug(sb, "<--- %s", __func__);
580
581 return o;
582
583 conv_err:
584 befs_error(sb, "Name using character set %s contains a character that "
585 "cannot be converted to unicode.", nls->charset);
586 befs_debug(sb, "<--- %s", __func__);
587 kfree(result);
588 return -EILSEQ;
589}
590
591/**
592 * befs_nls2utf - Convert NLS string to utf8 encodeing
593 * @sb: Superblock
594 * @src: Input string buffer in NLS format
595 * @srclen: Length of input string in bytes
596 * @dest: The output string in UTF-8 format
597 * @destlen: Length of the output buffer
598 *
599 * Converts input string @src, which is in the format of the loaded NLS map,
600 * into a utf8 string.
601 *
602 * The destination string @dest is allocated by this function and the caller is
603 * responsible for freeing it with kfree()
604 *
605 * On return, *@destlen is the length of @dest in bytes.
606 *
607 * On success, the return value is the number of utf8 characters written to
608 * the output buffer @dest.
609 *
610 * On Failure, a negative number coresponding to the error code is returned.
611 */
612
613static int
614befs_nls2utf(struct super_block *sb, const char *in,
615 int in_len, char **out, int *out_len)
616{
617 struct nls_table *nls = BEFS_SB(sb)->nls;
618 int i, o;
619 wchar_t uni;
620 int unilen, utflen;
621 char *result;
622 /* There're nls characters that will translate to 3-chars-wide UTF-8
623 * characters, a additional byte is needed to save the final \0
624 * in special cases */
625 int maxlen = (3 * in_len) + 1;
626
627 befs_debug(sb, "---> %s\n", __func__);
628
629 if (!nls) {
630 befs_error(sb, "%s called with no NLS table loaded.",
631 __func__);
632 return -EINVAL;
633 }
634
635 *out = result = kmalloc(maxlen, GFP_NOFS);
636 if (!*out) {
637 befs_error(sb, "%s cannot allocate memory", __func__);
638 *out_len = 0;
639 return -ENOMEM;
640 }
641
642 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
643
644 /* convert from nls to unicode */
645 unilen = nls->char2uni(&in[i], in_len - i, &uni);
646 if (unilen < 0)
647 goto conv_err;
648
649 /* convert from unicode to UTF-8 */
650 utflen = utf32_to_utf8(uni, &result[o], 3);
651 if (utflen <= 0)
652 goto conv_err;
653 }
654
655 result[o] = '\0';
656 *out_len = o;
657
658 befs_debug(sb, "<--- %s", __func__);
659
660 return i;
661
662 conv_err:
663 befs_error(sb, "Name using charecter set %s contains a charecter that "
664 "cannot be converted to unicode.", nls->charset);
665 befs_debug(sb, "<--- %s", __func__);
666 kfree(result);
667 return -EILSEQ;
668}
669
670/**
671 * Use the
672 *
673 */
674enum {
675 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
676};
677
678static const match_table_t befs_tokens = {
679 {Opt_uid, "uid=%d"},
680 {Opt_gid, "gid=%d"},
681 {Opt_charset, "iocharset=%s"},
682 {Opt_debug, "debug"},
683 {Opt_err, NULL}
684};
685
686static int
687parse_options(char *options, befs_mount_options * opts)
688{
689 char *p;
690 substring_t args[MAX_OPT_ARGS];
691 int option;
692 kuid_t uid;
693 kgid_t gid;
694
695 /* Initialize options */
696 opts->uid = GLOBAL_ROOT_UID;
697 opts->gid = GLOBAL_ROOT_GID;
698 opts->use_uid = 0;
699 opts->use_gid = 0;
700 opts->iocharset = NULL;
701 opts->debug = 0;
702
703 if (!options)
704 return 1;
705
706 while ((p = strsep(&options, ",")) != NULL) {
707 int token;
708 if (!*p)
709 continue;
710
711 token = match_token(p, befs_tokens, args);
712 switch (token) {
713 case Opt_uid:
714 if (match_int(&args[0], &option))
715 return 0;
716 uid = INVALID_UID;
717 if (option >= 0)
718 uid = make_kuid(current_user_ns(), option);
719 if (!uid_valid(uid)) {
720 pr_err("Invalid uid %d, "
721 "using default\n", option);
722 break;
723 }
724 opts->uid = uid;
725 opts->use_uid = 1;
726 break;
727 case Opt_gid:
728 if (match_int(&args[0], &option))
729 return 0;
730 gid = INVALID_GID;
731 if (option >= 0)
732 gid = make_kgid(current_user_ns(), option);
733 if (!gid_valid(gid)) {
734 pr_err("Invalid gid %d, "
735 "using default\n", option);
736 break;
737 }
738 opts->gid = gid;
739 opts->use_gid = 1;
740 break;
741 case Opt_charset:
742 kfree(opts->iocharset);
743 opts->iocharset = match_strdup(&args[0]);
744 if (!opts->iocharset) {
745 pr_err("allocation failure for "
746 "iocharset string\n");
747 return 0;
748 }
749 break;
750 case Opt_debug:
751 opts->debug = 1;
752 break;
753 default:
754 pr_err("Unrecognized mount option \"%s\" "
755 "or missing value\n", p);
756 return 0;
757 }
758 }
759 return 1;
760}
761
762/* This function has the responsibiltiy of getting the
763 * filesystem ready for unmounting.
764 * Basically, we free everything that we allocated in
765 * befs_read_inode
766 */
767static void
768befs_put_super(struct super_block *sb)
769{
770 kfree(BEFS_SB(sb)->mount_opts.iocharset);
771 BEFS_SB(sb)->mount_opts.iocharset = NULL;
772 unload_nls(BEFS_SB(sb)->nls);
773 kfree(sb->s_fs_info);
774 sb->s_fs_info = NULL;
775}
776
777/* Allocate private field of the superblock, fill it.
778 *
779 * Finish filling the public superblock fields
780 * Make the root directory
781 * Load a set of NLS translations if needed.
782 */
783static int
784befs_fill_super(struct super_block *sb, void *data, int silent)
785{
786 struct buffer_head *bh;
787 befs_sb_info *befs_sb;
788 befs_super_block *disk_sb;
789 struct inode *root;
790 long ret = -EINVAL;
791 const unsigned long sb_block = 0;
792 const off_t x86_sb_off = 512;
793
794 save_mount_options(sb, data);
795
796 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
797 if (sb->s_fs_info == NULL) {
798 pr_err("(%s): Unable to allocate memory for private "
799 "portion of superblock. Bailing.\n", sb->s_id);
800 goto unacquire_none;
801 }
802 befs_sb = BEFS_SB(sb);
803
804 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
805 befs_error(sb, "cannot parse mount options");
806 goto unacquire_priv_sbp;
807 }
808
809 befs_debug(sb, "---> %s", __func__);
810
811#ifndef CONFIG_BEFS_RW
812 if (!(sb->s_flags & MS_RDONLY)) {
813 befs_warning(sb,
814 "No write support. Marking filesystem read-only");
815 sb->s_flags |= MS_RDONLY;
816 }
817#endif /* CONFIG_BEFS_RW */
818
819 /*
820 * Set dummy blocksize to read super block.
821 * Will be set to real fs blocksize later.
822 *
823 * Linux 2.4.10 and later refuse to read blocks smaller than
824 * the hardsect size for the device. But we also need to read at
825 * least 1k to get the second 512 bytes of the volume.
826 * -WD 10-26-01
827 */
828 sb_min_blocksize(sb, 1024);
829
830 if (!(bh = sb_bread(sb, sb_block))) {
831 befs_error(sb, "unable to read superblock");
832 goto unacquire_priv_sbp;
833 }
834
835 /* account for offset of super block on x86 */
836 disk_sb = (befs_super_block *) bh->b_data;
837 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
838 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
839 befs_debug(sb, "Using PPC superblock location");
840 } else {
841 befs_debug(sb, "Using x86 superblock location");
842 disk_sb =
843 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
844 }
845
846 if (befs_load_sb(sb, disk_sb) != BEFS_OK)
847 goto unacquire_bh;
848
849 befs_dump_super_block(sb, disk_sb);
850
851 brelse(bh);
852
853 if (befs_check_sb(sb) != BEFS_OK)
854 goto unacquire_priv_sbp;
855
856 if( befs_sb->num_blocks > ~((sector_t)0) ) {
857 befs_error(sb, "blocks count: %llu "
858 "is larger than the host can use",
859 befs_sb->num_blocks);
860 goto unacquire_priv_sbp;
861 }
862
863 /*
864 * set up enough so that it can read an inode
865 * Fill in kernel superblock fields from private sb
866 */
867 sb->s_magic = BEFS_SUPER_MAGIC;
868 /* Set real blocksize of fs */
869 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
870 sb->s_op = &befs_sops;
871 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
872 if (IS_ERR(root)) {
873 ret = PTR_ERR(root);
874 goto unacquire_priv_sbp;
875 }
876 sb->s_root = d_make_root(root);
877 if (!sb->s_root) {
878 befs_error(sb, "get root inode failed");
879 goto unacquire_priv_sbp;
880 }
881
882 /* load nls library */
883 if (befs_sb->mount_opts.iocharset) {
884 befs_debug(sb, "Loading nls: %s",
885 befs_sb->mount_opts.iocharset);
886 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
887 if (!befs_sb->nls) {
888 befs_warning(sb, "Cannot load nls %s"
889 " loading default nls",
890 befs_sb->mount_opts.iocharset);
891 befs_sb->nls = load_nls_default();
892 }
893 /* load default nls if none is specified in mount options */
894 } else {
895 befs_debug(sb, "Loading default nls");
896 befs_sb->nls = load_nls_default();
897 }
898
899 return 0;
900/*****************/
901 unacquire_bh:
902 brelse(bh);
903
904 unacquire_priv_sbp:
905 kfree(befs_sb->mount_opts.iocharset);
906 kfree(sb->s_fs_info);
907
908 unacquire_none:
909 sb->s_fs_info = NULL;
910 return ret;
911}
912
913static int
914befs_remount(struct super_block *sb, int *flags, char *data)
915{
916 sync_filesystem(sb);
917 if (!(*flags & MS_RDONLY))
918 return -EINVAL;
919 return 0;
920}
921
922static int
923befs_statfs(struct dentry *dentry, struct kstatfs *buf)
924{
925 struct super_block *sb = dentry->d_sb;
926 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
927
928 befs_debug(sb, "---> %s", __func__);
929
930 buf->f_type = BEFS_SUPER_MAGIC;
931 buf->f_bsize = sb->s_blocksize;
932 buf->f_blocks = BEFS_SB(sb)->num_blocks;
933 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
934 buf->f_bavail = buf->f_bfree;
935 buf->f_files = 0; /* UNKNOWN */
936 buf->f_ffree = 0; /* UNKNOWN */
937 buf->f_fsid.val[0] = (u32)id;
938 buf->f_fsid.val[1] = (u32)(id >> 32);
939 buf->f_namelen = BEFS_NAME_LEN;
940
941 befs_debug(sb, "<--- %s", __func__);
942
943 return 0;
944}
945
946static struct dentry *
947befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
948 void *data)
949{
950 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
951}
952
953static struct file_system_type befs_fs_type = {
954 .owner = THIS_MODULE,
955 .name = "befs",
956 .mount = befs_mount,
957 .kill_sb = kill_block_super,
958 .fs_flags = FS_REQUIRES_DEV,
959};
960MODULE_ALIAS_FS("befs");
961
962static int __init
963init_befs_fs(void)
964{
965 int err;
966
967 pr_info("version: %s\n", BEFS_VERSION);
968
969 err = befs_init_inodecache();
970 if (err)
971 goto unacquire_none;
972
973 err = register_filesystem(&befs_fs_type);
974 if (err)
975 goto unacquire_inodecache;
976
977 return 0;
978
979unacquire_inodecache:
980 befs_destroy_inodecache();
981
982unacquire_none:
983 return err;
984}
985
986static void __exit
987exit_befs_fs(void)
988{
989 befs_destroy_inodecache();
990
991 unregister_filesystem(&befs_fs_type);
992}
993
994/*
995Macros that typecheck the init and exit functions,
996ensures that they are called at init and cleanup,
997and eliminates warnings about unused functions.
998*/
999module_init(init_befs_fs)
1000module_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/fs_context.h>
15#include <linux/fs_parser.h>
16#include <linux/errno.h>
17#include <linux/stat.h>
18#include <linux/nls.h>
19#include <linux/buffer_head.h>
20#include <linux/vfs.h>
21#include <linux/namei.h>
22#include <linux/sched.h>
23#include <linux/cred.h>
24#include <linux/exportfs.h>
25#include <linux/seq_file.h>
26#include <linux/blkdev.h>
27
28#include "befs.h"
29#include "btree.h"
30#include "inode.h"
31#include "datastream.h"
32#include "super.h"
33#include "io.h"
34
35MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
36MODULE_AUTHOR("Will Dyson");
37MODULE_LICENSE("GPL");
38
39/* The units the vfs expects inode->i_blocks to be in */
40#define VFS_BLOCK_SIZE 512
41
42static int befs_readdir(struct file *, struct dir_context *);
43static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
44static int befs_read_folio(struct file *file, struct folio *folio);
45static sector_t befs_bmap(struct address_space *mapping, sector_t block);
46static struct dentry *befs_lookup(struct inode *, struct dentry *,
47 unsigned int);
48static struct inode *befs_iget(struct super_block *, unsigned long);
49static struct inode *befs_alloc_inode(struct super_block *sb);
50static void befs_free_inode(struct inode *inode);
51static void befs_destroy_inodecache(void);
52static int befs_symlink_read_folio(struct file *, struct folio *);
53static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
54 char **out, int *out_len);
55static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
56 char **out, int *out_len);
57static void befs_put_super(struct super_block *);
58static int befs_statfs(struct dentry *, struct kstatfs *);
59static int befs_show_options(struct seq_file *, struct dentry *);
60static struct dentry *befs_fh_to_dentry(struct super_block *sb,
61 struct fid *fid, int fh_len, int fh_type);
62static struct dentry *befs_fh_to_parent(struct super_block *sb,
63 struct fid *fid, int fh_len, int fh_type);
64static struct dentry *befs_get_parent(struct dentry *child);
65static void befs_free_fc(struct fs_context *fc);
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 .show_options = befs_show_options,
73};
74
75/* slab cache for befs_inode_info objects */
76static struct kmem_cache *befs_inode_cachep;
77
78static const struct file_operations befs_dir_operations = {
79 .read = generic_read_dir,
80 .iterate_shared = befs_readdir,
81 .llseek = generic_file_llseek,
82};
83
84static const struct inode_operations befs_dir_inode_operations = {
85 .lookup = befs_lookup,
86};
87
88static const struct address_space_operations befs_aops = {
89 .read_folio = befs_read_folio,
90 .bmap = befs_bmap,
91};
92
93static const struct address_space_operations befs_symlink_aops = {
94 .read_folio = befs_symlink_read_folio,
95};
96
97static const struct export_operations befs_export_operations = {
98 .encode_fh = generic_encode_ino32_fh,
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_set_mtime(inode,
364 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16,
365 0);/* lower 16 bits are not a time */
366 inode_set_ctime_to_ts(inode, inode_get_mtime(inode));
367 inode_set_atime_to_ts(inode, inode_get_mtime(inode));
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 strscpy(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_ACCOUNT,
438 offsetof(struct befs_inode_info,
439 i_data.symlink),
440 sizeof_field(struct befs_inode_info,
441 i_data.symlink),
442 init_once);
443 if (befs_inode_cachep == NULL)
444 return -ENOMEM;
445
446 return 0;
447}
448
449/* Called at fs teardown.
450 *
451 * Taken from NFS implementation by Al Viro.
452 */
453static void
454befs_destroy_inodecache(void)
455{
456 /*
457 * Make sure all delayed rcu free inodes are flushed before we
458 * destroy cache.
459 */
460 rcu_barrier();
461 kmem_cache_destroy(befs_inode_cachep);
462}
463
464/*
465 * The inode of symbolic link is different to data stream.
466 * The data stream become link name. Unless the LONG_SYMLINK
467 * flag is set.
468 */
469static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
470{
471 struct inode *inode = folio->mapping->host;
472 struct super_block *sb = inode->i_sb;
473 struct befs_inode_info *befs_ino = BEFS_I(inode);
474 befs_data_stream *data = &befs_ino->i_data.ds;
475 befs_off_t len = data->size;
476 char *link = folio_address(folio);
477 int err = -EIO;
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 err = 0;
491fail:
492 folio_end_read(folio, err == 0);
493 return err;
494}
495
496/*
497 * UTF-8 to NLS charset convert routine
498 *
499 * Uses uni2char() / char2uni() rather than the nls tables directly
500 */
501static int
502befs_utf2nls(struct super_block *sb, const char *in,
503 int in_len, char **out, int *out_len)
504{
505 struct nls_table *nls = BEFS_SB(sb)->nls;
506 int i, o;
507 unicode_t uni;
508 int unilen, utflen;
509 char *result;
510 /* The utf8->nls conversion won't make the final nls string bigger
511 * than the utf one, but if the string is pure ascii they'll have the
512 * same width and an extra char is needed to save the additional \0
513 */
514 int maxlen = in_len + 1;
515
516 befs_debug(sb, "---> %s", __func__);
517
518 if (!nls) {
519 befs_error(sb, "%s called with no NLS table loaded", __func__);
520 return -EINVAL;
521 }
522
523 *out = result = kmalloc(maxlen, GFP_NOFS);
524 if (!*out)
525 return -ENOMEM;
526
527 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
528
529 /* convert from UTF-8 to Unicode */
530 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
531 if (utflen < 0)
532 goto conv_err;
533
534 /* convert from Unicode to nls */
535 if (uni > MAX_WCHAR_T)
536 goto conv_err;
537 unilen = nls->uni2char(uni, &result[o], in_len - o);
538 if (unilen < 0)
539 goto conv_err;
540 }
541 result[o] = '\0';
542 *out_len = o;
543
544 befs_debug(sb, "<--- %s", __func__);
545
546 return o;
547
548conv_err:
549 befs_error(sb, "Name using character set %s contains a character that "
550 "cannot be converted to unicode.", nls->charset);
551 befs_debug(sb, "<--- %s", __func__);
552 kfree(result);
553 return -EILSEQ;
554}
555
556/**
557 * befs_nls2utf - Convert NLS string to utf8 encodeing
558 * @sb: Superblock
559 * @in: Input string buffer in NLS format
560 * @in_len: Length of input string in bytes
561 * @out: The output string in UTF-8 format
562 * @out_len: Length of the output buffer
563 *
564 * Converts input string @in, which is in the format of the loaded NLS map,
565 * into a utf8 string.
566 *
567 * The destination string @out is allocated by this function and the caller is
568 * responsible for freeing it with kfree()
569 *
570 * On return, *@out_len is the length of @out in bytes.
571 *
572 * On success, the return value is the number of utf8 characters written to
573 * the output buffer @out.
574 *
575 * On Failure, a negative number coresponding to the error code is returned.
576 */
577
578static int
579befs_nls2utf(struct super_block *sb, const char *in,
580 int in_len, char **out, int *out_len)
581{
582 struct nls_table *nls = BEFS_SB(sb)->nls;
583 int i, o;
584 wchar_t uni;
585 int unilen, utflen;
586 char *result;
587 /*
588 * There are nls characters that will translate to 3-chars-wide UTF-8
589 * characters, an additional byte is needed to save the final \0
590 * in special cases
591 */
592 int maxlen = (3 * in_len) + 1;
593
594 befs_debug(sb, "---> %s\n", __func__);
595
596 if (!nls) {
597 befs_error(sb, "%s called with no NLS table loaded.",
598 __func__);
599 return -EINVAL;
600 }
601
602 *out = result = kmalloc(maxlen, GFP_NOFS);
603 if (!*out) {
604 *out_len = 0;
605 return -ENOMEM;
606 }
607
608 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
609
610 /* convert from nls to unicode */
611 unilen = nls->char2uni(&in[i], in_len - i, &uni);
612 if (unilen < 0)
613 goto conv_err;
614
615 /* convert from unicode to UTF-8 */
616 utflen = utf32_to_utf8(uni, &result[o], 3);
617 if (utflen <= 0)
618 goto conv_err;
619 }
620
621 result[o] = '\0';
622 *out_len = o;
623
624 befs_debug(sb, "<--- %s", __func__);
625
626 return i;
627
628conv_err:
629 befs_error(sb, "Name using character set %s contains a character that "
630 "cannot be converted to unicode.", nls->charset);
631 befs_debug(sb, "<--- %s", __func__);
632 kfree(result);
633 return -EILSEQ;
634}
635
636static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
637 uint32_t generation)
638{
639 /* No need to handle i_generation */
640 return befs_iget(sb, ino);
641}
642
643/*
644 * Map a NFS file handle to a corresponding dentry
645 */
646static struct dentry *befs_fh_to_dentry(struct super_block *sb,
647 struct fid *fid, int fh_len, int fh_type)
648{
649 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
650 befs_nfs_get_inode);
651}
652
653/*
654 * Find the parent for a file specified by NFS handle
655 */
656static struct dentry *befs_fh_to_parent(struct super_block *sb,
657 struct fid *fid, int fh_len, int fh_type)
658{
659 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
660 befs_nfs_get_inode);
661}
662
663static struct dentry *befs_get_parent(struct dentry *child)
664{
665 struct inode *parent;
666 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
667
668 parent = befs_iget(child->d_sb,
669 (unsigned long)befs_ino->i_parent.start);
670 return d_obtain_alias(parent);
671}
672
673enum {
674 Opt_uid, Opt_gid, Opt_charset, Opt_debug,
675};
676
677static const struct fs_parameter_spec befs_param_spec[] = {
678 fsparam_uid ("uid", Opt_uid),
679 fsparam_gid ("gid", Opt_gid),
680 fsparam_string ("iocharset", Opt_charset),
681 fsparam_flag ("debug", Opt_debug),
682 {}
683};
684
685static int
686befs_parse_param(struct fs_context *fc, struct fs_parameter *param)
687{
688 struct befs_mount_options *opts = fc->fs_private;
689 int token;
690 struct fs_parse_result result;
691
692 /* befs ignores all options on remount */
693 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
694 return 0;
695
696 token = fs_parse(fc, befs_param_spec, param, &result);
697 if (token < 0)
698 return token;
699
700 switch (token) {
701 case Opt_uid:
702 opts->uid = result.uid;
703 opts->use_uid = 1;
704 break;
705 case Opt_gid:
706 opts->gid = result.gid;
707 opts->use_gid = 1;
708 break;
709 case Opt_charset:
710 kfree(opts->iocharset);
711 opts->iocharset = param->string;
712 param->string = NULL;
713 break;
714 case Opt_debug:
715 opts->debug = 1;
716 break;
717 default:
718 return -EINVAL;
719 }
720 return 0;
721}
722
723static int befs_show_options(struct seq_file *m, struct dentry *root)
724{
725 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
726 struct befs_mount_options *opts = &befs_sb->mount_opts;
727
728 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
729 seq_printf(m, ",uid=%u",
730 from_kuid_munged(&init_user_ns, opts->uid));
731 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
732 seq_printf(m, ",gid=%u",
733 from_kgid_munged(&init_user_ns, opts->gid));
734 if (opts->iocharset)
735 seq_printf(m, ",charset=%s", opts->iocharset);
736 if (opts->debug)
737 seq_puts(m, ",debug");
738 return 0;
739}
740
741/* This function has the responsibiltiy of getting the
742 * filesystem ready for unmounting.
743 * Basically, we free everything that we allocated in
744 * befs_read_inode
745 */
746static void
747befs_put_super(struct super_block *sb)
748{
749 kfree(BEFS_SB(sb)->mount_opts.iocharset);
750 BEFS_SB(sb)->mount_opts.iocharset = NULL;
751 unload_nls(BEFS_SB(sb)->nls);
752 kfree(sb->s_fs_info);
753 sb->s_fs_info = NULL;
754}
755
756/*
757 * Copy the parsed options into the sbi mount_options member
758 */
759static void
760befs_set_options(struct befs_sb_info *sbi, struct befs_mount_options *opts)
761{
762 sbi->mount_opts.uid = opts->uid;
763 sbi->mount_opts.gid = opts->gid;
764 sbi->mount_opts.use_uid = opts->use_uid;
765 sbi->mount_opts.use_gid = opts->use_gid;
766 sbi->mount_opts.debug = opts->debug;
767 sbi->mount_opts.iocharset = opts->iocharset;
768 opts->iocharset = NULL;
769}
770
771/* Allocate private field of the superblock, fill it.
772 *
773 * Finish filling the public superblock fields
774 * Make the root directory
775 * Load a set of NLS translations if needed.
776 */
777static int
778befs_fill_super(struct super_block *sb, struct fs_context *fc)
779{
780 struct buffer_head *bh;
781 struct befs_sb_info *befs_sb;
782 befs_super_block *disk_sb;
783 struct inode *root;
784 long ret = -EINVAL;
785 const unsigned long sb_block = 0;
786 const off_t x86_sb_off = 512;
787 int blocksize;
788 struct befs_mount_options *parsed_opts = fc->fs_private;
789 int silent = fc->sb_flags & SB_SILENT;
790
791 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
792 if (sb->s_fs_info == NULL)
793 goto unacquire_none;
794
795 befs_sb = BEFS_SB(sb);
796
797 befs_set_options(befs_sb, parsed_opts);
798
799 befs_debug(sb, "---> %s", __func__);
800
801 if (!sb_rdonly(sb)) {
802 befs_warning(sb,
803 "No write support. Marking filesystem read-only");
804 sb->s_flags |= SB_RDONLY;
805 }
806
807 /*
808 * Set dummy blocksize to read super block.
809 * Will be set to real fs blocksize later.
810 *
811 * Linux 2.4.10 and later refuse to read blocks smaller than
812 * the logical block size for the device. But we also need to read at
813 * least 1k to get the second 512 bytes of the volume.
814 */
815 blocksize = sb_min_blocksize(sb, 1024);
816 if (!blocksize) {
817 if (!silent)
818 befs_error(sb, "unable to set blocksize");
819 goto unacquire_priv_sbp;
820 }
821
822 bh = sb_bread(sb, sb_block);
823 if (!bh) {
824 if (!silent)
825 befs_error(sb, "unable to read superblock");
826 goto unacquire_priv_sbp;
827 }
828
829 /* account for offset of super block on x86 */
830 disk_sb = (befs_super_block *) bh->b_data;
831 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
832 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
833 befs_debug(sb, "Using PPC superblock location");
834 } else {
835 befs_debug(sb, "Using x86 superblock location");
836 disk_sb =
837 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
838 }
839
840 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
841 (befs_check_sb(sb) != BEFS_OK))
842 goto unacquire_bh;
843
844 befs_dump_super_block(sb, disk_sb);
845
846 brelse(bh);
847
848 if (befs_sb->num_blocks > ~((sector_t)0)) {
849 if (!silent)
850 befs_error(sb, "blocks count: %llu is larger than the host can use",
851 befs_sb->num_blocks);
852 goto unacquire_priv_sbp;
853 }
854
855 /*
856 * set up enough so that it can read an inode
857 * Fill in kernel superblock fields from private sb
858 */
859 sb->s_magic = BEFS_SUPER_MAGIC;
860 /* Set real blocksize of fs */
861 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
862 sb->s_op = &befs_sops;
863 sb->s_export_op = &befs_export_operations;
864 sb->s_time_min = 0;
865 sb->s_time_max = 0xffffffffffffll;
866 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
867 if (IS_ERR(root)) {
868 ret = PTR_ERR(root);
869 goto unacquire_priv_sbp;
870 }
871 sb->s_root = d_make_root(root);
872 if (!sb->s_root) {
873 if (!silent)
874 befs_error(sb, "get root inode failed");
875 goto unacquire_priv_sbp;
876 }
877
878 /* load nls library */
879 if (befs_sb->mount_opts.iocharset) {
880 befs_debug(sb, "Loading nls: %s",
881 befs_sb->mount_opts.iocharset);
882 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
883 if (!befs_sb->nls) {
884 befs_warning(sb, "Cannot load nls %s"
885 " loading default nls",
886 befs_sb->mount_opts.iocharset);
887 befs_sb->nls = load_nls_default();
888 }
889 /* load default nls if none is specified in mount options */
890 } else {
891 befs_debug(sb, "Loading default nls");
892 befs_sb->nls = load_nls_default();
893 }
894
895 return 0;
896
897unacquire_bh:
898 brelse(bh);
899
900unacquire_priv_sbp:
901 kfree(befs_sb->mount_opts.iocharset);
902 kfree(sb->s_fs_info);
903 sb->s_fs_info = NULL;
904
905unacquire_none:
906 return ret;
907}
908
909static int
910befs_reconfigure(struct fs_context *fc)
911{
912 sync_filesystem(fc->root->d_sb);
913 if (!(fc->sb_flags & SB_RDONLY))
914 return -EINVAL;
915 return 0;
916}
917
918static int
919befs_statfs(struct dentry *dentry, struct kstatfs *buf)
920{
921 struct super_block *sb = dentry->d_sb;
922 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
923
924 befs_debug(sb, "---> %s", __func__);
925
926 buf->f_type = BEFS_SUPER_MAGIC;
927 buf->f_bsize = sb->s_blocksize;
928 buf->f_blocks = BEFS_SB(sb)->num_blocks;
929 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
930 buf->f_bavail = buf->f_bfree;
931 buf->f_files = 0; /* UNKNOWN */
932 buf->f_ffree = 0; /* UNKNOWN */
933 buf->f_fsid = u64_to_fsid(id);
934 buf->f_namelen = BEFS_NAME_LEN;
935
936 befs_debug(sb, "<--- %s", __func__);
937
938 return 0;
939}
940
941static int befs_get_tree(struct fs_context *fc)
942{
943 return get_tree_bdev(fc, befs_fill_super);
944}
945
946static const struct fs_context_operations befs_context_ops = {
947 .parse_param = befs_parse_param,
948 .get_tree = befs_get_tree,
949 .reconfigure = befs_reconfigure,
950 .free = befs_free_fc,
951};
952
953static int befs_init_fs_context(struct fs_context *fc)
954{
955 struct befs_mount_options *opts;
956
957 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
958 if (!opts)
959 return -ENOMEM;
960
961 /* Initialize options */
962 opts->uid = GLOBAL_ROOT_UID;
963 opts->gid = GLOBAL_ROOT_GID;
964
965 fc->fs_private = opts;
966 fc->ops = &befs_context_ops;
967
968 return 0;
969}
970
971static void befs_free_fc(struct fs_context *fc)
972{
973 struct befs_mount_options *opts = fc->fs_private;
974
975 kfree(opts->iocharset);
976 kfree(fc->fs_private);
977}
978
979static struct file_system_type befs_fs_type = {
980 .owner = THIS_MODULE,
981 .name = "befs",
982 .kill_sb = kill_block_super,
983 .fs_flags = FS_REQUIRES_DEV,
984 .init_fs_context = befs_init_fs_context,
985 .parameters = befs_param_spec,
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)