1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/befs/linuxvfs.c
4 *
5 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
6 *
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/errno.h>
15#include <linux/stat.h>
16#include <linux/nls.h>
17#include <linux/buffer_head.h>
18#include <linux/vfs.h>
19#include <linux/parser.h>
20#include <linux/namei.h>
21#include <linux/sched.h>
22#include <linux/cred.h>
23#include <linux/exportfs.h>
24#include <linux/seq_file.h>
25#include <linux/blkdev.h>
26
27#include "befs.h"
28#include "btree.h"
29#include "inode.h"
30#include "datastream.h"
31#include "super.h"
32#include "io.h"
33
34MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
35MODULE_AUTHOR("Will Dyson");
36MODULE_LICENSE("GPL");
37
38/* The units the vfs expects inode->i_blocks to be in */
39#define VFS_BLOCK_SIZE 512
40
41static int befs_readdir(struct file *, struct dir_context *);
42static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
43static int befs_read_folio(struct file *file, struct folio *folio);
44static sector_t befs_bmap(struct address_space *mapping, sector_t block);
45static struct dentry *befs_lookup(struct inode *, struct dentry *,
46 unsigned int);
47static struct inode *befs_iget(struct super_block *, unsigned long);
48static struct inode *befs_alloc_inode(struct super_block *sb);
49static void befs_free_inode(struct inode *inode);
50static void befs_destroy_inodecache(void);
51static int befs_symlink_read_folio(struct file *, struct folio *);
52static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
53 char **out, int *out_len);
54static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
55 char **out, int *out_len);
56static void befs_put_super(struct super_block *);
57static int befs_remount(struct super_block *, int *, char *);
58static int befs_statfs(struct dentry *, struct kstatfs *);
59static int befs_show_options(struct seq_file *, struct dentry *);
60static int parse_options(char *, struct befs_mount_options *);
61static struct dentry *befs_fh_to_dentry(struct super_block *sb,
62 struct fid *fid, int fh_len, int fh_type);
63static struct dentry *befs_fh_to_parent(struct super_block *sb,
64 struct fid *fid, int fh_len, int fh_type);
65static struct dentry *befs_get_parent(struct dentry *child);
66
67static const struct super_operations befs_sops = {
68 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
69 .free_inode = befs_free_inode, /* deallocate an inode */
70 .put_super = befs_put_super, /* uninit super */
71 .statfs = befs_statfs, /* statfs */
72 .remount_fs = befs_remount,
73 .show_options = befs_show_options,
74};
75
76/* slab cache for befs_inode_info objects */
77static struct kmem_cache *befs_inode_cachep;
78
79static const struct file_operations befs_dir_operations = {
80 .read = generic_read_dir,
81 .iterate_shared = befs_readdir,
82 .llseek = generic_file_llseek,
83};
84
85static const struct inode_operations befs_dir_inode_operations = {
86 .lookup = befs_lookup,
87};
88
89static const struct address_space_operations befs_aops = {
90 .read_folio = befs_read_folio,
91 .bmap = befs_bmap,
92};
93
94static const struct address_space_operations befs_symlink_aops = {
95 .read_folio = befs_symlink_read_folio,
96};
97
98static const struct export_operations befs_export_operations = {
99 .encode_fh = generic_encode_ino32_fh,
100 .fh_to_dentry = befs_fh_to_dentry,
101 .fh_to_parent = befs_fh_to_parent,
102 .get_parent = befs_get_parent,
103};
104
105/*
106 * Called by generic_file_read() to read a folio of data
107 *
108 * In turn, simply calls a generic block read function and
109 * passes it the address of befs_get_block, for mapping file
110 * positions to disk blocks.
111 */
112static int befs_read_folio(struct file *file, struct folio *folio)
113{
114 return block_read_full_folio(folio, 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, fmt: "---> befs_get_block() for inode %lu, block %ld",
143 (unsigned long)inode->i_ino, (long)block);
144 if (create) {
145 befs_error(sb, fmt: "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, data: ds, fblock: block, run: &run);
152 if (res != BEFS_OK) {
153 befs_error(sb,
154 fmt: "<--- %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, iaddr: &run);
161
162 map_bh(bh: bh_result, sb: inode->i_sb, block: disk_off);
163
164 befs_debug(sb, fmt: "<--- %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(inode: 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, fmt: "---> %s name %pd inode %ld", __func__,
184 dentry, dir->i_ino);
185
186 /* Convert to UTF-8 */
187 if (BEFS_SB(super: sb)->nls) {
188 ret =
189 befs_nls2utf(sb, in: name, strlen(name), out: &utfname, out_len: &utfnamelen);
190 if (ret < 0) {
191 befs_debug(sb, fmt: "<--- %s ERROR", __func__);
192 return ERR_PTR(error: ret);
193 }
194 ret = befs_btree_find(sb, ds, key: utfname, value: &offset);
195 kfree(objp: utfname);
196
197 } else {
198 ret = befs_btree_find(sb, ds, key: name, value: &offset);
199 }
200
201 if (ret == BEFS_BT_NOT_FOUND) {
202 befs_debug(sb, fmt: "<--- %s %pd not found", __func__, dentry);
203 inode = NULL;
204 } else if (ret != BEFS_OK || offset == 0) {
205 befs_error(sb, fmt: "<--- %s Error", __func__);
206 inode = ERR_PTR(error: -ENODATA);
207 } else {
208 inode = befs_iget(dir->i_sb, (ino_t) offset);
209 }
210 befs_debug(sb, fmt: "<--- %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(f: 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, fmt: "---> %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, key_no: ctx->pos, BEFS_NAME_LEN + 1,
231 keybuf, keysize: &keysize, value: &value);
232
233 if (result == BEFS_ERR) {
234 befs_debug(sb, fmt: "<--- %s ERROR", __func__);
235 befs_error(sb, fmt: "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, fmt: "<--- %s END", __func__);
241 return 0;
242
243 } else if (result == BEFS_BT_EMPTY) {
244 befs_debug(sb, fmt: "<--- %s Empty directory", __func__);
245 return 0;
246 }
247
248 /* Convert to NLS */
249 if (BEFS_SB(super: sb)->nls) {
250 char *nlsname;
251 int nlsnamelen;
252
253 result =
254 befs_utf2nls(sb, in: keybuf, in_len: keysize, out: &nlsname,
255 out_len: &nlsnamelen);
256 if (result < 0) {
257 befs_debug(sb, fmt: "<--- %s ERROR", __func__);
258 return result;
259 }
260 if (!dir_emit(ctx, name: nlsname, namelen: nlsnamelen,
261 ino: (ino_t) value, DT_UNKNOWN)) {
262 kfree(objp: nlsname);
263 return 0;
264 }
265 kfree(objp: nlsname);
266 } else {
267 if (!dir_emit(ctx, name: keybuf, namelen: keysize,
268 ino: (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 = alloc_inode_sb(sb, cache: 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(s: befs_inode_cachep, objp: 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(super: sb);
303 struct befs_inode_info *befs_ino;
304 struct inode *inode;
305
306 befs_debug(sb, fmt: "---> %s inode = %lu", __func__, ino);
307
308 inode = iget_locked(sb, ino);
309 if (!inode)
310 return ERR_PTR(error: -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, blockno: inode->i_ino);
318
319 befs_debug(sb, fmt: " 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, block: inode->i_ino);
324 if (!bh) {
325 befs_error(sb, fmt: "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: inode->i_ino) != BEFS_OK) {
335 befs_error(sb, fmt: "Bad inode: %lu", inode->i_ino);
336 goto unacquire_bh;
337 }
338
339 inode->i_mode = (umode_t) fs32_to_cpu(sb, n: 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(from: &init_user_ns, uid: fs32_to_cpu(sb, n: raw_inode->uid));
349 inode->i_gid = befs_sb->mount_opts.use_gid ?
350 befs_sb->mount_opts.gid :
351 make_kgid(from: &init_user_ns, gid: fs32_to_cpu(sb, n: raw_inode->gid));
352
353 set_nlink(inode, nlink: 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_set_mtime(inode,
365 sec: fs64_to_cpu(sb, n: raw_inode->last_modified_time) >> 16,
366 nsec: 0);/* lower 16 bits are not a time */
367 inode_set_ctime_to_ts(inode, ts: inode_get_mtime(inode));
368 inode_set_atime_to_ts(inode, ts: inode_get_mtime(inode));
369
370 befs_ino->i_inode_num = fsrun_to_cpu(sb, n: raw_inode->inode_num);
371 befs_ino->i_parent = fsrun_to_cpu(sb, n: raw_inode->parent);
372 befs_ino->i_attribute = fsrun_to_cpu(sb, n: raw_inode->attributes);
373 befs_ino->i_flags = fs32_to_cpu(sb, n: 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 strscpy(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, n: &raw_inode->data.datastream);
385
386 num_blks = befs_count_blocks(sb, ds: &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, fmt: "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, fmt: "<--- %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, fmt: "<--- %s - Bad inode", __func__);
426 return ERR_PTR(error: -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(name: "befs_inode_cache",
437 size: sizeof(struct befs_inode_info), align: 0,
438 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
439 offsetof(struct befs_inode_info,
440 i_data.symlink),
441 sizeof_field(struct befs_inode_info,
442 i_data.symlink),
443 ctor: init_once);
444 if (befs_inode_cachep == NULL)
445 return -ENOMEM;
446
447 return 0;
448}
449
450/* Called at fs teardown.
451 *
452 * Taken from NFS implementation by Al Viro.
453 */
454static void
455befs_destroy_inodecache(void)
456{
457 /*
458 * Make sure all delayed rcu free inodes are flushed before we
459 * destroy cache.
460 */
461 rcu_barrier();
462 kmem_cache_destroy(s: befs_inode_cachep);
463}
464
465/*
466 * The inode of symbolic link is different to data stream.
467 * The data stream become link name. Unless the LONG_SYMLINK
468 * flag is set.
469 */
470static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
471{
472 struct inode *inode = folio->mapping->host;
473 struct super_block *sb = inode->i_sb;
474 struct befs_inode_info *befs_ino = BEFS_I(inode);
475 befs_data_stream *data = &befs_ino->i_data.ds;
476 befs_off_t len = data->size;
477 char *link = folio_address(folio);
478
479 if (len == 0 || len > PAGE_SIZE) {
480 befs_error(sb, fmt: "Long symlink with illegal length");
481 goto fail;
482 }
483 befs_debug(sb, fmt: "Follow long symlink");
484
485 if (befs_read_lsymlink(sb, data, buff: link, len) != len) {
486 befs_error(sb, fmt: "Failed to read entire long symlink");
487 goto fail;
488 }
489 link[len - 1] = '\0';
490 folio_mark_uptodate(folio);
491 folio_unlock(folio);
492 return 0;
493fail:
494 folio_set_error(folio);
495 folio_unlock(folio);
496 return -EIO;
497}
498
499/*
500 * UTF-8 to NLS charset convert routine
501 *
502 * Uses uni2char() / char2uni() rather than the nls tables directly
503 */
504static int
505befs_utf2nls(struct super_block *sb, const char *in,
506 int in_len, char **out, int *out_len)
507{
508 struct nls_table *nls = BEFS_SB(super: sb)->nls;
509 int i, o;
510 unicode_t uni;
511 int unilen, utflen;
512 char *result;
513 /* The utf8->nls conversion won't make the final nls string bigger
514 * than the utf one, but if the string is pure ascii they'll have the
515 * same width and an extra char is needed to save the additional \0
516 */
517 int maxlen = in_len + 1;
518
519 befs_debug(sb, fmt: "---> %s", __func__);
520
521 if (!nls) {
522 befs_error(sb, fmt: "%s called with no NLS table loaded", __func__);
523 return -EINVAL;
524 }
525
526 *out = result = kmalloc(size: maxlen, GFP_NOFS);
527 if (!*out)
528 return -ENOMEM;
529
530 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
531
532 /* convert from UTF-8 to Unicode */
533 utflen = utf8_to_utf32(s: &in[i], len: in_len - i, pu: &uni);
534 if (utflen < 0)
535 goto conv_err;
536
537 /* convert from Unicode to nls */
538 if (uni > MAX_WCHAR_T)
539 goto conv_err;
540 unilen = nls->uni2char(uni, &result[o], in_len - o);
541 if (unilen < 0)
542 goto conv_err;
543 }
544 result[o] = '\0';
545 *out_len = o;
546
547 befs_debug(sb, fmt: "<--- %s", __func__);
548
549 return o;
550
551conv_err:
552 befs_error(sb, fmt: "Name using character set %s contains a character that "
553 "cannot be converted to unicode.", nls->charset);
554 befs_debug(sb, fmt: "<--- %s", __func__);
555 kfree(objp: result);
556 return -EILSEQ;
557}
558
559/**
560 * befs_nls2utf - Convert NLS string to utf8 encodeing
561 * @sb: Superblock
562 * @in: Input string buffer in NLS format
563 * @in_len: Length of input string in bytes
564 * @out: The output string in UTF-8 format
565 * @out_len: Length of the output buffer
566 *
567 * Converts input string @in, which is in the format of the loaded NLS map,
568 * into a utf8 string.
569 *
570 * The destination string @out is allocated by this function and the caller is
571 * responsible for freeing it with kfree()
572 *
573 * On return, *@out_len is the length of @out in bytes.
574 *
575 * On success, the return value is the number of utf8 characters written to
576 * the output buffer @out.
577 *
578 * On Failure, a negative number coresponding to the error code is returned.
579 */
580
581static int
582befs_nls2utf(struct super_block *sb, const char *in,
583 int in_len, char **out, int *out_len)
584{
585 struct nls_table *nls = BEFS_SB(super: sb)->nls;
586 int i, o;
587 wchar_t uni;
588 int unilen, utflen;
589 char *result;
590 /*
591 * There are nls characters that will translate to 3-chars-wide UTF-8
592 * characters, an additional byte is needed to save the final \0
593 * in special cases
594 */
595 int maxlen = (3 * in_len) + 1;
596
597 befs_debug(sb, fmt: "---> %s\n", __func__);
598
599 if (!nls) {
600 befs_error(sb, fmt: "%s called with no NLS table loaded.",
601 __func__);
602 return -EINVAL;
603 }
604
605 *out = result = kmalloc(size: maxlen, GFP_NOFS);
606 if (!*out) {
607 *out_len = 0;
608 return -ENOMEM;
609 }
610
611 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
612
613 /* convert from nls to unicode */
614 unilen = nls->char2uni(&in[i], in_len - i, &uni);
615 if (unilen < 0)
616 goto conv_err;
617
618 /* convert from unicode to UTF-8 */
619 utflen = utf32_to_utf8(u: uni, s: &result[o], maxlen: 3);
620 if (utflen <= 0)
621 goto conv_err;
622 }
623
624 result[o] = '\0';
625 *out_len = o;
626
627 befs_debug(sb, fmt: "<--- %s", __func__);
628
629 return i;
630
631conv_err:
632 befs_error(sb, fmt: "Name using character set %s contains a character that "
633 "cannot be converted to unicode.", nls->charset);
634 befs_debug(sb, fmt: "<--- %s", __func__);
635 kfree(objp: result);
636 return -EILSEQ;
637}
638
639static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
640 uint32_t generation)
641{
642 /* No need to handle i_generation */
643 return befs_iget(sb, ino);
644}
645
646/*
647 * Map a NFS file handle to a corresponding dentry
648 */
649static struct dentry *befs_fh_to_dentry(struct super_block *sb,
650 struct fid *fid, int fh_len, int fh_type)
651{
652 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
653 get_inode: befs_nfs_get_inode);
654}
655
656/*
657 * Find the parent for a file specified by NFS handle
658 */
659static struct dentry *befs_fh_to_parent(struct super_block *sb,
660 struct fid *fid, int fh_len, int fh_type)
661{
662 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
663 get_inode: befs_nfs_get_inode);
664}
665
666static struct dentry *befs_get_parent(struct dentry *child)
667{
668 struct inode *parent;
669 struct befs_inode_info *befs_ino = BEFS_I(inode: d_inode(dentry: child));
670
671 parent = befs_iget(sb: child->d_sb,
672 ino: (unsigned long)befs_ino->i_parent.start);
673 return d_obtain_alias(parent);
674}
675
676enum {
677 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
678};
679
680static const match_table_t befs_tokens = {
681 {Opt_uid, "uid=%d"},
682 {Opt_gid, "gid=%d"},
683 {Opt_charset, "iocharset=%s"},
684 {Opt_debug, "debug"},
685 {Opt_err, NULL}
686};
687
688static int
689parse_options(char *options, struct befs_mount_options *opts)
690{
691 char *p;
692 substring_t args[MAX_OPT_ARGS];
693 int option;
694 kuid_t uid;
695 kgid_t gid;
696
697 /* Initialize options */
698 opts->uid = GLOBAL_ROOT_UID;
699 opts->gid = GLOBAL_ROOT_GID;
700 opts->use_uid = 0;
701 opts->use_gid = 0;
702 opts->iocharset = NULL;
703 opts->debug = 0;
704
705 if (!options)
706 return 1;
707
708 while ((p = strsep(&options, ",")) != NULL) {
709 int token;
710
711 if (!*p)
712 continue;
713
714 token = match_token(p, befs_tokens, args);
715 switch (token) {
716 case Opt_uid:
717 if (match_int(&args[0], &option))
718 return 0;
719 uid = INVALID_UID;
720 if (option >= 0)
721 uid = make_kuid(current_user_ns(), option);
722 if (!uid_valid(uid)) {
723 pr_err("Invalid uid %d, "
724 "using default\n", option);
725 break;
726 }
727 opts->uid = uid;
728 opts->use_uid = 1;
729 break;
730 case Opt_gid:
731 if (match_int(&args[0], &option))
732 return 0;
733 gid = INVALID_GID;
734 if (option >= 0)
735 gid = make_kgid(current_user_ns(), option);
736 if (!gid_valid(gid)) {
737 pr_err("Invalid gid %d, "
738 "using default\n", option);
739 break;
740 }
741 opts->gid = gid;
742 opts->use_gid = 1;
743 break;
744 case Opt_charset:
745 kfree(opts->iocharset);
746 opts->iocharset = match_strdup(&args[0]);
747 if (!opts->iocharset) {
748 pr_err("allocation failure for "
749 "iocharset string\n");
750 return 0;
751 }
752 break;
753 case Opt_debug:
754 opts->debug = 1;
755 break;
756 default:
757 pr_err("Unrecognized mount option \"%s\" "
758 "or missing value\n", p);
759 return 0;
760 }
761 }
762 return 1;
763}
764
765static int befs_show_options(struct seq_file *m, struct dentry *root)
766{
767 struct befs_sb_info *befs_sb = BEFS_SB(super: root->d_sb);
768 struct befs_mount_options *opts = &befs_sb->mount_opts;
769
770 if (!uid_eq(left: opts->uid, GLOBAL_ROOT_UID))
771 seq_printf(m, ",uid=%u",
772 from_kuid_munged(&init_user_ns, opts->uid));
773 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
774 seq_printf(m, ",gid=%u",
775 from_kgid_munged(&init_user_ns, opts->gid));
776 if (opts->iocharset)
777 seq_printf(m, ",charset=%s", opts->iocharset);
778 if (opts->debug)
779 seq_puts(m, ",debug");
780 return 0;
781}
782
783/* This function has the responsibiltiy of getting the
784 * filesystem ready for unmounting.
785 * Basically, we free everything that we allocated in
786 * befs_read_inode
787 */
788static void
789befs_put_super(struct super_block *sb)
790{
791 kfree(objp: BEFS_SB(super: sb)->mount_opts.iocharset);
792 BEFS_SB(super: sb)->mount_opts.iocharset = NULL;
793 unload_nls(BEFS_SB(super: sb)->nls);
794 kfree(objp: sb->s_fs_info);
795 sb->s_fs_info = NULL;
796}
797
798/* Allocate private field of the superblock, fill it.
799 *
800 * Finish filling the public superblock fields
801 * Make the root directory
802 * Load a set of NLS translations if needed.
803 */
804static int
805befs_fill_super(struct super_block *sb, void *data, int silent)
806{
807 struct buffer_head *bh;
808 struct befs_sb_info *befs_sb;
809 befs_super_block *disk_sb;
810 struct inode *root;
811 long ret = -EINVAL;
812 const unsigned long sb_block = 0;
813 const off_t x86_sb_off = 512;
814 int blocksize;
815
816 sb->s_fs_info = kzalloc(size: sizeof(*befs_sb), GFP_KERNEL);
817 if (sb->s_fs_info == NULL)
818 goto unacquire_none;
819
820 befs_sb = BEFS_SB(super: sb);
821
822 if (!parse_options(options: (char *) data, opts: &befs_sb->mount_opts)) {
823 if (!silent)
824 befs_error(sb, fmt: "cannot parse mount options");
825 goto unacquire_priv_sbp;
826 }
827
828 befs_debug(sb, fmt: "---> %s", __func__);
829
830 if (!sb_rdonly(sb)) {
831 befs_warning(sb,
832 fmt: "No write support. Marking filesystem read-only");
833 sb->s_flags |= SB_RDONLY;
834 }
835
836 /*
837 * Set dummy blocksize to read super block.
838 * Will be set to real fs blocksize later.
839 *
840 * Linux 2.4.10 and later refuse to read blocks smaller than
841 * the logical block size for the device. But we also need to read at
842 * least 1k to get the second 512 bytes of the volume.
843 */
844 blocksize = sb_min_blocksize(sb, 1024);
845 if (!blocksize) {
846 if (!silent)
847 befs_error(sb, fmt: "unable to set blocksize");
848 goto unacquire_priv_sbp;
849 }
850
851 bh = sb_bread(sb, block: sb_block);
852 if (!bh) {
853 if (!silent)
854 befs_error(sb, fmt: "unable to read superblock");
855 goto unacquire_priv_sbp;
856 }
857
858 /* account for offset of super block on x86 */
859 disk_sb = (befs_super_block *) bh->b_data;
860 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
861 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
862 befs_debug(sb, fmt: "Using PPC superblock location");
863 } else {
864 befs_debug(sb, fmt: "Using x86 superblock location");
865 disk_sb =
866 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
867 }
868
869 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
870 (befs_check_sb(sb) != BEFS_OK))
871 goto unacquire_bh;
872
873 befs_dump_super_block(sb, disk_sb);
874
875 brelse(bh);
876
877 if (befs_sb->num_blocks > ~((sector_t)0)) {
878 if (!silent)
879 befs_error(sb, fmt: "blocks count: %llu is larger than the host can use",
880 befs_sb->num_blocks);
881 goto unacquire_priv_sbp;
882 }
883
884 /*
885 * set up enough so that it can read an inode
886 * Fill in kernel superblock fields from private sb
887 */
888 sb->s_magic = BEFS_SUPER_MAGIC;
889 /* Set real blocksize of fs */
890 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
891 sb->s_op = &befs_sops;
892 sb->s_export_op = &befs_export_operations;
893 sb->s_time_min = 0;
894 sb->s_time_max = 0xffffffffffffll;
895 root = befs_iget(sb, ino: iaddr2blockno(sb, iaddr: &(befs_sb->root_dir)));
896 if (IS_ERR(ptr: root)) {
897 ret = PTR_ERR(ptr: root);
898 goto unacquire_priv_sbp;
899 }
900 sb->s_root = d_make_root(root);
901 if (!sb->s_root) {
902 if (!silent)
903 befs_error(sb, fmt: "get root inode failed");
904 goto unacquire_priv_sbp;
905 }
906
907 /* load nls library */
908 if (befs_sb->mount_opts.iocharset) {
909 befs_debug(sb, fmt: "Loading nls: %s",
910 befs_sb->mount_opts.iocharset);
911 befs_sb->nls = load_nls(charset: befs_sb->mount_opts.iocharset);
912 if (!befs_sb->nls) {
913 befs_warning(sb, fmt: "Cannot load nls %s"
914 " loading default nls",
915 befs_sb->mount_opts.iocharset);
916 befs_sb->nls = load_nls_default();
917 }
918 /* load default nls if none is specified in mount options */
919 } else {
920 befs_debug(sb, fmt: "Loading default nls");
921 befs_sb->nls = load_nls_default();
922 }
923
924 return 0;
925
926unacquire_bh:
927 brelse(bh);
928
929unacquire_priv_sbp:
930 kfree(objp: befs_sb->mount_opts.iocharset);
931 kfree(objp: sb->s_fs_info);
932 sb->s_fs_info = NULL;
933
934unacquire_none:
935 return ret;
936}
937
938static int
939befs_remount(struct super_block *sb, int *flags, char *data)
940{
941 sync_filesystem(sb);
942 if (!(*flags & SB_RDONLY))
943 return -EINVAL;
944 return 0;
945}
946
947static int
948befs_statfs(struct dentry *dentry, struct kstatfs *buf)
949{
950 struct super_block *sb = dentry->d_sb;
951 u64 id = huge_encode_dev(dev: sb->s_bdev->bd_dev);
952
953 befs_debug(sb, fmt: "---> %s", __func__);
954
955 buf->f_type = BEFS_SUPER_MAGIC;
956 buf->f_bsize = sb->s_blocksize;
957 buf->f_blocks = BEFS_SB(super: sb)->num_blocks;
958 buf->f_bfree = BEFS_SB(super: sb)->num_blocks - BEFS_SB(super: sb)->used_blocks;
959 buf->f_bavail = buf->f_bfree;
960 buf->f_files = 0; /* UNKNOWN */
961 buf->f_ffree = 0; /* UNKNOWN */
962 buf->f_fsid = u64_to_fsid(v: id);
963 buf->f_namelen = BEFS_NAME_LEN;
964
965 befs_debug(sb, fmt: "<--- %s", __func__);
966
967 return 0;
968}
969
970static struct dentry *
971befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
972 void *data)
973{
974 return mount_bdev(fs_type, flags, dev_name, data, fill_super: befs_fill_super);
975}
976
977static struct file_system_type befs_fs_type = {
978 .owner = THIS_MODULE,
979 .name = "befs",
980 .mount = befs_mount,
981 .kill_sb = kill_block_super,
982 .fs_flags = FS_REQUIRES_DEV,
983};
984MODULE_ALIAS_FS("befs");
985
986static int __init
987init_befs_fs(void)
988{
989 int err;
990
991 pr_info("version: %s\n", BEFS_VERSION);
992
993 err = befs_init_inodecache();
994 if (err)
995 goto unacquire_none;
996
997 err = register_filesystem(&befs_fs_type);
998 if (err)
999 goto unacquire_inodecache;
1000
1001 return 0;
1002
1003unacquire_inodecache:
1004 befs_destroy_inodecache();
1005
1006unacquire_none:
1007 return err;
1008}
1009
1010static void __exit
1011exit_befs_fs(void)
1012{
1013 befs_destroy_inodecache();
1014
1015 unregister_filesystem(&befs_fs_type);
1016}
1017
1018/*
1019 * Macros that typecheck the init and exit functions,
1020 * ensures that they are called at init and cleanup,
1021 * and eliminates warnings about unused functions.
1022 */
1023module_init(init_befs_fs)
1024module_exit(exit_befs_fs)
1025

source code of linux/fs/befs/linuxvfs.c