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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/befs/linuxvfs.c
4 *
5 * Copyright (C) 2001 Will Dyson <[email protected]
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/filelock.h>
18#include <linux/stat.h>
19#include <linux/nls.h>
20#include <linux/buffer_head.h>
21#include <linux/vfs.h>
22#include <linux/namei.h>
23#include <linux/sched.h>
24#include <linux/cred.h>
25#include <linux/exportfs.h>
26#include <linux/seq_file.h>
27#include <linux/blkdev.h>
28
29#include "befs.h"
30#include "btree.h"
31#include "inode.h"
32#include "datastream.h"
33#include "super.h"
34#include "io.h"
35
36MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
37MODULE_AUTHOR("Will Dyson");
38MODULE_LICENSE("GPL");
39
40/* The units the vfs expects inode->i_blocks to be in */
41#define VFS_BLOCK_SIZE 512
42
43static int befs_readdir(struct file *, struct dir_context *);
44static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
45static int befs_read_folio(struct file *file, struct folio *folio);
46static sector_t befs_bmap(struct address_space *mapping, sector_t block);
47static struct dentry *befs_lookup(struct inode *, struct dentry *,
48 unsigned int);
49static struct inode *befs_iget(struct super_block *, unsigned long);
50static struct inode *befs_alloc_inode(struct super_block *sb);
51static void befs_free_inode(struct inode *inode);
52static void befs_destroy_inodecache(void);
53static int befs_symlink_read_folio(struct file *, struct folio *);
54static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
55 char **out, int *out_len);
56static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
57 char **out, int *out_len);
58static void befs_put_super(struct super_block *);
59static int befs_statfs(struct dentry *, struct kstatfs *);
60static int befs_show_options(struct seq_file *, struct dentry *);
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);
66static void befs_free_fc(struct fs_context *fc);
67
68static const struct super_operations befs_sops = {
69 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
70 .free_inode = befs_free_inode, /* deallocate an inode */
71 .put_super = befs_put_super, /* uninit super */
72 .statfs = befs_statfs, /* statfs */
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 .setlease = generic_setlease,
84};
85
86static const struct inode_operations befs_dir_inode_operations = {
87 .lookup = befs_lookup,
88};
89
90static const struct address_space_operations befs_aops = {
91 .read_folio = befs_read_folio,
92 .bmap = befs_bmap,
93};
94
95static const struct address_space_operations befs_symlink_aops = {
96 .read_folio = befs_symlink_read_folio,
97};
98
99static const struct export_operations befs_export_operations = {
100 .encode_fh = generic_encode_ino32_fh,
101 .fh_to_dentry = befs_fh_to_dentry,
102 .fh_to_parent = befs_fh_to_parent,
103 .get_parent = befs_get_parent,
104};
105
106/*
107 * Called by generic_file_read() to read a folio of data
108 *
109 * In turn, simply calls a generic block read function and
110 * passes it the address of befs_get_block, for mapping file
111 * positions to disk blocks.
112 */
113static int befs_read_folio(struct file *file, struct folio *folio)
114{
115 return block_read_full_folio(folio, befs_get_block);
116}
117
118static sector_t
119befs_bmap(struct address_space *mapping, sector_t block)
120{
121 return generic_block_bmap(mapping, block, befs_get_block);
122}
123
124/*
125 * Generic function to map a file position (block) to a
126 * disk offset (passed back in bh_result).
127 *
128 * Used by many higher level functions.
129 *
130 * Calls befs_fblock2brun() in datastream.c to do the real work.
131 */
132
133static int
134befs_get_block(struct inode *inode, sector_t block,
135 struct buffer_head *bh_result, int create)
136{
137 struct super_block *sb = inode->i_sb;
138 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
139 befs_block_run run = BAD_IADDR;
140 int res;
141 ulong disk_off;
142
143 befs_debug(sb, "---> befs_get_block() for inode %llu, block %ld",
144 inode->i_ino, (long)block);
145 if (create) {
146 befs_error(sb, "befs_get_block() was asked to write to "
147 "block %ld in inode %llu", (long)block,
148 inode->i_ino);
149 return -EPERM;
150 }
151
152 res = befs_fblock2brun(sb, ds, block, &run);
153 if (res != BEFS_OK) {
154 befs_error(sb,
155 "<--- %s for inode %llu, block %ld ERROR",
156 __func__, inode->i_ino,
157 (long)block);
158 return -EFBIG;
159 }
160
161 disk_off = (ulong) iaddr2blockno(sb, &run);
162
163 map_bh(bh_result, inode->i_sb, disk_off);
164
165 befs_debug(sb, "<--- %s for inode %llu, block %ld, disk address %lu",
166 __func__, inode->i_ino, (long)block,
167 (unsigned long)disk_off);
168
169 return 0;
170}
171
172static struct dentry *
173befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
174{
175 struct inode *inode;
176 struct super_block *sb = dir->i_sb;
177 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
178 befs_off_t offset;
179 int ret;
180 int utfnamelen;
181 char *utfname;
182 const char *name = dentry->d_name.name;
183
184 befs_debug(sb, "---> %s name %pd inode %llu", __func__,
185 dentry, dir->i_ino);
186
187 /* Convert to UTF-8 */
188 if (BEFS_SB(sb)->nls) {
189 ret =
190 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
191 if (ret < 0) {
192 befs_debug(sb, "<--- %s ERROR", __func__);
193 return ERR_PTR(ret);
194 }
195 ret = befs_btree_find(sb, ds, utfname, &offset);
196 kfree(utfname);
197
198 } else {
199 ret = befs_btree_find(sb, ds, name, &offset);
200 }
201
202 if (ret == BEFS_BT_NOT_FOUND) {
203 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
204 inode = NULL;
205 } else if (ret != BEFS_OK || offset == 0) {
206 befs_error(sb, "<--- %s Error", __func__);
207 inode = ERR_PTR(-ENODATA);
208 } else {
209 inode = befs_iget(dir->i_sb, (ino_t) offset);
210 }
211 befs_debug(sb, "<--- %s", __func__);
212
213 return d_splice_alias(inode, dentry);
214}
215
216static int
217befs_readdir(struct file *file, struct dir_context *ctx)
218{
219 struct inode *inode = file_inode(file);
220 struct super_block *sb = inode->i_sb;
221 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
222 befs_off_t value;
223 int result;
224 size_t keysize;
225 char keybuf[BEFS_NAME_LEN + 1];
226
227 befs_debug(sb, "---> %s name %pD, inode %llu, ctx->pos %lld",
228 __func__, file, inode->i_ino, ctx->pos);
229
230 while (1) {
231 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
232 keybuf, &keysize, &value);
233
234 if (result == BEFS_ERR) {
235 befs_debug(sb, "<--- %s ERROR", __func__);
236 befs_error(sb, "IO error reading %pD (inode %llu)",
237 file, inode->i_ino);
238 return -EIO;
239
240 } else if (result == BEFS_BT_END) {
241 befs_debug(sb, "<--- %s END", __func__);
242 return 0;
243
244 } else if (result == BEFS_BT_EMPTY) {
245 befs_debug(sb, "<--- %s Empty directory", __func__);
246 return 0;
247 }
248
249 /* Convert to NLS */
250 if (BEFS_SB(sb)->nls) {
251 char *nlsname;
252 int nlsnamelen;
253
254 result =
255 befs_utf2nls(sb, keybuf, keysize, &nlsname,
256 &nlsnamelen);
257 if (result < 0) {
258 befs_debug(sb, "<--- %s ERROR", __func__);
259 return result;
260 }
261 if (!dir_emit(ctx, nlsname, nlsnamelen,
262 (ino_t) value, DT_UNKNOWN)) {
263 kfree(nlsname);
264 return 0;
265 }
266 kfree(nlsname);
267 } else {
268 if (!dir_emit(ctx, keybuf, keysize,
269 (ino_t) value, DT_UNKNOWN))
270 return 0;
271 }
272 ctx->pos++;
273 }
274}
275
276static struct inode *
277befs_alloc_inode(struct super_block *sb)
278{
279 struct befs_inode_info *bi;
280
281 bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL);
282 if (!bi)
283 return NULL;
284 return &bi->vfs_inode;
285}
286
287static void befs_free_inode(struct inode *inode)
288{
289 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
290}
291
292static void init_once(void *foo)
293{
294 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
295
296 inode_init_once(&bi->vfs_inode);
297}
298
299static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
300{
301 struct buffer_head *bh;
302 befs_inode *raw_inode;
303 struct befs_sb_info *befs_sb = BEFS_SB(sb);
304 struct befs_inode_info *befs_ino;
305 struct inode *inode;
306
307 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
308
309 inode = iget_locked(sb, ino);
310 if (!inode)
311 return ERR_PTR(-ENOMEM);
312 if (!(inode_state_read_once(inode) & I_NEW))
313 return inode;
314
315 befs_ino = BEFS_I(inode);
316
317 /* convert from vfs's inode number to befs's inode number */
318 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
319
320 befs_debug(sb, " real inode number [%u, %hu, %hu]",
321 befs_ino->i_inode_num.allocation_group,
322 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
323
324 bh = sb_bread(sb, inode->i_ino);
325 if (!bh) {
326 befs_error(sb, "unable to read inode block - "
327 "inode = %llu", inode->i_ino);
328 goto unacquire_none;
329 }
330
331 raw_inode = (befs_inode *) bh->b_data;
332
333 befs_dump_inode(sb, raw_inode);
334
335 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
336 befs_error(sb, "Bad inode: %llu", inode->i_ino);
337 goto unacquire_bh;
338 }
339
340 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
341
342 /*
343 * set uid and gid. But since current BeOS is single user OS, so
344 * you can change by "uid" or "gid" options.
345 */
346
347 inode->i_uid = befs_sb->mount_opts.use_uid ?
348 befs_sb->mount_opts.uid :
349 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
350 inode->i_gid = befs_sb->mount_opts.use_gid ?
351 befs_sb->mount_opts.gid :
352 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
353
354 set_nlink(inode, 1);
355
356 /*
357 * BEFS's time is 64 bits, but current VFS is 32 bits...
358 * BEFS don't have access time. Nor inode change time. VFS
359 * doesn't have creation time.
360 * Also, the lower 16 bits of the last_modified_time and
361 * create_time are just a counter to help ensure uniqueness
362 * for indexing purposes. (PFD, page 54)
363 */
364
365 inode_set_mtime(inode,
366 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16,
367 0);/* lower 16 bits are not a time */
368 inode_set_ctime_to_ts(inode, inode_get_mtime(inode));
369 inode_set_atime_to_ts(inode, inode_get_mtime(inode));
370
371 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
372 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
373 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
374 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
375
376 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
377 inode->i_size = 0;
378 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
379 strscpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
380 BEFS_SYMLINK_LEN);
381 } else {
382 int num_blks;
383
384 befs_ino->i_data.ds =
385 fsds_to_cpu(sb, &raw_inode->data.datastream);
386
387 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
388 inode->i_blocks =
389 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
390 inode->i_size = befs_ino->i_data.ds.size;
391 }
392
393 inode->i_mapping->a_ops = &befs_aops;
394
395 if (S_ISREG(inode->i_mode)) {
396 inode->i_fop = &generic_ro_fops;
397 } else if (S_ISDIR(inode->i_mode)) {
398 inode->i_op = &befs_dir_inode_operations;
399 inode->i_fop = &befs_dir_operations;
400 } else if (S_ISLNK(inode->i_mode)) {
401 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
402 inode->i_op = &page_symlink_inode_operations;
403 inode_nohighmem(inode);
404 inode->i_mapping->a_ops = &befs_symlink_aops;
405 } else {
406 inode->i_link = befs_ino->i_data.symlink;
407 inode->i_op = &simple_symlink_inode_operations;
408 }
409 } else {
410 befs_error(sb, "Inode %llu is not a regular file, "
411 "directory or symlink. THAT IS WRONG! BeFS has no "
412 "on disk special files", inode->i_ino);
413 goto unacquire_bh;
414 }
415
416 brelse(bh);
417 befs_debug(sb, "<--- %s", __func__);
418 unlock_new_inode(inode);
419 return inode;
420
421unacquire_bh:
422 brelse(bh);
423
424unacquire_none:
425 iget_failed(inode);
426 befs_debug(sb, "<--- %s - Bad inode", __func__);
427 return ERR_PTR(-EIO);
428}
429
430/* Initialize the inode cache. Called at fs setup.
431 *
432 * Taken from NFS implementation by Al Viro.
433 */
434static int __init
435befs_init_inodecache(void)
436{
437 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
438 sizeof(struct befs_inode_info), 0,
439 SLAB_RECLAIM_ACCOUNT | 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_read_folio(struct file *unused, struct folio *folio)
472{
473 struct inode *inode = folio->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 = folio_address(folio);
479 int err = -EIO;
480
481 if (len == 0 || len > PAGE_SIZE) {
482 befs_error(sb, "Long symlink with illegal length");
483 goto fail;
484 }
485 befs_debug(sb, "Follow long symlink");
486
487 if (befs_read_lsymlink(sb, data, link, len) != len) {
488 befs_error(sb, "Failed to read entire long symlink");
489 goto fail;
490 }
491 link[len - 1] = '\0';
492 err = 0;
493fail:
494 folio_end_read(folio, err == 0);
495 return err;
496}
497
498/*
499 * UTF-8 to NLS charset convert routine
500 *
501 * Uses uni2char() / char2uni() rather than the nls tables directly
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 return -ENOMEM;
528
529 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
530
531 /* convert from UTF-8 to Unicode */
532 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
533 if (utflen < 0)
534 goto conv_err;
535
536 /* convert from Unicode to nls */
537 if (uni > MAX_WCHAR_T)
538 goto conv_err;
539 unilen = nls->uni2char(uni, &result[o], in_len - o);
540 if (unilen < 0)
541 goto conv_err;
542 }
543 result[o] = '\0';
544 *out_len = o;
545
546 befs_debug(sb, "<--- %s", __func__);
547
548 return o;
549
550conv_err:
551 befs_error(sb, "Name using character set %s contains a character that "
552 "cannot be converted to unicode.", nls->charset);
553 befs_debug(sb, "<--- %s", __func__);
554 kfree(result);
555 return -EILSEQ;
556}
557
558/**
559 * befs_nls2utf - Convert NLS string to utf8 encodeing
560 * @sb: Superblock
561 * @in: Input string buffer in NLS format
562 * @in_len: Length of input string in bytes
563 * @out: The output string in UTF-8 format
564 * @out_len: Length of the output buffer
565 *
566 * Converts input string @in, which is in the format of the loaded NLS map,
567 * into a utf8 string.
568 *
569 * The destination string @out is allocated by this function and the caller is
570 * responsible for freeing it with kfree()
571 *
572 * On return, *@out_len is the length of @out in bytes.
573 *
574 * On success, the return value is the number of utf8 characters written to
575 * the output buffer @out.
576 *
577 * On Failure, a negative number coresponding to the error code is returned.
578 */
579
580static int
581befs_nls2utf(struct super_block *sb, const char *in,
582 int in_len, char **out, int *out_len)
583{
584 struct nls_table *nls = BEFS_SB(sb)->nls;
585 int i, o;
586 wchar_t uni;
587 int unilen, utflen;
588 char *result;
589 /*
590 * There are nls characters that will translate to 3-chars-wide UTF-8
591 * characters, an additional byte is needed to save the final \0
592 * in special cases
593 */
594 int maxlen = (3 * in_len) + 1;
595
596 befs_debug(sb, "---> %s\n", __func__);
597
598 if (!nls) {
599 befs_error(sb, "%s called with no NLS table loaded.",
600 __func__);
601 return -EINVAL;
602 }
603
604 *out = result = kmalloc(maxlen, GFP_NOFS);
605 if (!*out) {
606 *out_len = 0;
607 return -ENOMEM;
608 }
609
610 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
611
612 /* convert from nls to unicode */
613 unilen = nls->char2uni(&in[i], in_len - i, &uni);
614 if (unilen < 0)
615 goto conv_err;
616
617 /* convert from unicode to UTF-8 */
618 utflen = utf32_to_utf8(uni, &result[o], 3);
619 if (utflen <= 0)
620 goto conv_err;
621 }
622
623 result[o] = '\0';
624 *out_len = o;
625
626 befs_debug(sb, "<--- %s", __func__);
627
628 return i;
629
630conv_err:
631 befs_error(sb, "Name using character set %s contains a character that "
632 "cannot be converted to unicode.", nls->charset);
633 befs_debug(sb, "<--- %s", __func__);
634 kfree(result);
635 return -EILSEQ;
636}
637
638static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
639 uint32_t generation)
640{
641 /* No need to handle i_generation */
642 return befs_iget(sb, ino);
643}
644
645/*
646 * Map a NFS file handle to a corresponding dentry
647 */
648static struct dentry *befs_fh_to_dentry(struct super_block *sb,
649 struct fid *fid, int fh_len, int fh_type)
650{
651 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
652 befs_nfs_get_inode);
653}
654
655/*
656 * Find the parent for a file specified by NFS handle
657 */
658static struct dentry *befs_fh_to_parent(struct super_block *sb,
659 struct fid *fid, int fh_len, int fh_type)
660{
661 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
662 befs_nfs_get_inode);
663}
664
665static struct dentry *befs_get_parent(struct dentry *child)
666{
667 struct inode *parent;
668 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
669
670 parent = befs_iget(child->d_sb,
671 (unsigned long)befs_ino->i_parent.start);
672 return d_obtain_alias(parent);
673}
674
675enum {
676 Opt_uid, Opt_gid, Opt_charset, Opt_debug,
677};
678
679static const struct fs_parameter_spec befs_param_spec[] = {
680 fsparam_uid ("uid", Opt_uid),
681 fsparam_gid ("gid", Opt_gid),
682 fsparam_string ("iocharset", Opt_charset),
683 fsparam_flag ("debug", Opt_debug),
684 {}
685};
686
687static int
688befs_parse_param(struct fs_context *fc, struct fs_parameter *param)
689{
690 struct befs_mount_options *opts = fc->fs_private;
691 int token;
692 struct fs_parse_result result;
693
694 /* befs ignores all options on remount */
695 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
696 return 0;
697
698 token = fs_parse(fc, befs_param_spec, param, &result);
699 if (token < 0)
700 return token;
701
702 switch (token) {
703 case Opt_uid:
704 opts->uid = result.uid;
705 opts->use_uid = 1;
706 break;
707 case Opt_gid:
708 opts->gid = result.gid;
709 opts->use_gid = 1;
710 break;
711 case Opt_charset:
712 kfree(opts->iocharset);
713 opts->iocharset = param->string;
714 param->string = NULL;
715 break;
716 case Opt_debug:
717 opts->debug = 1;
718 break;
719 default:
720 return -EINVAL;
721 }
722 return 0;
723}
724
725static int befs_show_options(struct seq_file *m, struct dentry *root)
726{
727 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
728 struct befs_mount_options *opts = &befs_sb->mount_opts;
729
730 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
731 seq_printf(m, ",uid=%u",
732 from_kuid_munged(&init_user_ns, opts->uid));
733 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
734 seq_printf(m, ",gid=%u",
735 from_kgid_munged(&init_user_ns, opts->gid));
736 if (opts->iocharset)
737 seq_printf(m, ",charset=%s", opts->iocharset);
738 if (opts->debug)
739 seq_puts(m, ",debug");
740 return 0;
741}
742
743/* This function has the responsibiltiy of getting the
744 * filesystem ready for unmounting.
745 * Basically, we free everything that we allocated in
746 * befs_read_inode
747 */
748static void
749befs_put_super(struct super_block *sb)
750{
751 kfree(BEFS_SB(sb)->mount_opts.iocharset);
752 BEFS_SB(sb)->mount_opts.iocharset = NULL;
753 unload_nls(BEFS_SB(sb)->nls);
754 kfree(sb->s_fs_info);
755 sb->s_fs_info = NULL;
756}
757
758/*
759 * Copy the parsed options into the sbi mount_options member
760 */
761static void
762befs_set_options(struct befs_sb_info *sbi, struct befs_mount_options *opts)
763{
764 sbi->mount_opts.uid = opts->uid;
765 sbi->mount_opts.gid = opts->gid;
766 sbi->mount_opts.use_uid = opts->use_uid;
767 sbi->mount_opts.use_gid = opts->use_gid;
768 sbi->mount_opts.debug = opts->debug;
769 sbi->mount_opts.iocharset = opts->iocharset;
770 opts->iocharset = NULL;
771}
772
773/* Allocate private field of the superblock, fill it.
774 *
775 * Finish filling the public superblock fields
776 * Make the root directory
777 * Load a set of NLS translations if needed.
778 */
779static int
780befs_fill_super(struct super_block *sb, struct fs_context *fc)
781{
782 struct buffer_head *bh;
783 struct befs_sb_info *befs_sb;
784 befs_super_block *disk_sb;
785 struct inode *root;
786 long ret = -EINVAL;
787 const unsigned long sb_block = 0;
788 const off_t x86_sb_off = 512;
789 int blocksize;
790 struct befs_mount_options *parsed_opts = fc->fs_private;
791 int silent = fc->sb_flags & SB_SILENT;
792
793 sb->s_fs_info = kzalloc_obj(*befs_sb);
794 if (sb->s_fs_info == NULL)
795 goto unacquire_none;
796
797 befs_sb = BEFS_SB(sb);
798
799 befs_set_options(befs_sb, parsed_opts);
800
801 befs_debug(sb, "---> %s", __func__);
802
803 if (!sb_rdonly(sb)) {
804 befs_warning(sb,
805 "No write support. Marking filesystem read-only");
806 sb->s_flags |= SB_RDONLY;
807 }
808
809 /*
810 * Set dummy blocksize to read super block.
811 * Will be set to real fs blocksize later.
812 *
813 * Linux 2.4.10 and later refuse to read blocks smaller than
814 * the logical block size for the device. But we also need to read at
815 * least 1k to get the second 512 bytes of the volume.
816 */
817 blocksize = sb_min_blocksize(sb, 1024);
818 if (!blocksize) {
819 if (!silent)
820 befs_error(sb, "unable to set blocksize");
821 goto unacquire_priv_sbp;
822 }
823
824 bh = sb_bread(sb, sb_block);
825 if (!bh) {
826 if (!silent)
827 befs_error(sb, "unable to read superblock");
828 goto unacquire_priv_sbp;
829 }
830
831 /* account for offset of super block on x86 */
832 disk_sb = (befs_super_block *) bh->b_data;
833 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
834 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
835 befs_debug(sb, "Using PPC superblock location");
836 } else {
837 befs_debug(sb, "Using x86 superblock location");
838 disk_sb =
839 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
840 }
841
842 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
843 (befs_check_sb(sb) != BEFS_OK))
844 goto unacquire_bh;
845
846 befs_dump_super_block(sb, disk_sb);
847
848 brelse(bh);
849
850 if (befs_sb->num_blocks > ~((sector_t)0)) {
851 if (!silent)
852 befs_error(sb, "blocks count: %llu is larger than the host can use",
853 befs_sb->num_blocks);
854 goto unacquire_priv_sbp;
855 }
856
857 /*
858 * set up enough so that it can read an inode
859 * Fill in kernel superblock fields from private sb
860 */
861 sb->s_magic = BEFS_SUPER_MAGIC;
862 /* Set real blocksize of fs */
863 if (!sb_set_blocksize(sb, (ulong) befs_sb->block_size))
864 goto unacquire_priv_sbp;
865 sb->s_op = &befs_sops;
866 sb->s_export_op = &befs_export_operations;
867 sb->s_time_min = 0;
868 sb->s_time_max = 0xffffffffffffll;
869 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
870 if (IS_ERR(root)) {
871 ret = PTR_ERR(root);
872 goto unacquire_priv_sbp;
873 }
874 sb->s_root = d_make_root(root);
875 if (!sb->s_root) {
876 if (!silent)
877 befs_error(sb, "get root inode failed");
878 goto unacquire_priv_sbp;
879 }
880
881 /* load nls library */
882 if (befs_sb->mount_opts.iocharset) {
883 befs_debug(sb, "Loading nls: %s",
884 befs_sb->mount_opts.iocharset);
885 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
886 if (!befs_sb->nls) {
887 befs_warning(sb, "Cannot load nls %s"
888 " loading default nls",
889 befs_sb->mount_opts.iocharset);
890 befs_sb->nls = load_nls_default();
891 }
892 /* load default nls if none is specified in mount options */
893 } else {
894 befs_debug(sb, "Loading default nls");
895 befs_sb->nls = load_nls_default();
896 }
897
898 return 0;
899
900unacquire_bh:
901 brelse(bh);
902
903unacquire_priv_sbp:
904 kfree(befs_sb->mount_opts.iocharset);
905 kfree(sb->s_fs_info);
906 sb->s_fs_info = NULL;
907
908unacquire_none:
909 return ret;
910}
911
912static int
913befs_reconfigure(struct fs_context *fc)
914{
915 sync_filesystem(fc->root->d_sb);
916 if (!(fc->sb_flags & SB_RDONLY))
917 return -EINVAL;
918 return 0;
919}
920
921static int
922befs_statfs(struct dentry *dentry, struct kstatfs *buf)
923{
924 struct super_block *sb = dentry->d_sb;
925 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
926
927 befs_debug(sb, "---> %s", __func__);
928
929 buf->f_type = BEFS_SUPER_MAGIC;
930 buf->f_bsize = sb->s_blocksize;
931 buf->f_blocks = BEFS_SB(sb)->num_blocks;
932 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
933 buf->f_bavail = buf->f_bfree;
934 buf->f_files = 0; /* UNKNOWN */
935 buf->f_ffree = 0; /* UNKNOWN */
936 buf->f_fsid = u64_to_fsid(id);
937 buf->f_namelen = BEFS_NAME_LEN;
938
939 befs_debug(sb, "<--- %s", __func__);
940
941 return 0;
942}
943
944static int befs_get_tree(struct fs_context *fc)
945{
946 return get_tree_bdev(fc, befs_fill_super);
947}
948
949static const struct fs_context_operations befs_context_ops = {
950 .parse_param = befs_parse_param,
951 .get_tree = befs_get_tree,
952 .reconfigure = befs_reconfigure,
953 .free = befs_free_fc,
954};
955
956static int befs_init_fs_context(struct fs_context *fc)
957{
958 struct befs_mount_options *opts;
959
960 opts = kzalloc_obj(*opts);
961 if (!opts)
962 return -ENOMEM;
963
964 /* Initialize options */
965 opts->uid = GLOBAL_ROOT_UID;
966 opts->gid = GLOBAL_ROOT_GID;
967
968 fc->fs_private = opts;
969 fc->ops = &befs_context_ops;
970
971 return 0;
972}
973
974static void befs_free_fc(struct fs_context *fc)
975{
976 struct befs_mount_options *opts = fc->fs_private;
977
978 kfree(opts->iocharset);
979 kfree(fc->fs_private);
980}
981
982static struct file_system_type befs_fs_type = {
983 .owner = THIS_MODULE,
984 .name = "befs",
985 .kill_sb = kill_block_super,
986 .fs_flags = FS_REQUIRES_DEV,
987 .init_fs_context = befs_init_fs_context,
988 .parameters = befs_param_spec,
989};
990MODULE_ALIAS_FS("befs");
991
992static int __init
993init_befs_fs(void)
994{
995 int err;
996
997 pr_info("version: %s\n", BEFS_VERSION);
998
999 err = befs_init_inodecache();
1000 if (err)
1001 goto unacquire_none;
1002
1003 err = register_filesystem(&befs_fs_type);
1004 if (err)
1005 goto unacquire_inodecache;
1006
1007 return 0;
1008
1009unacquire_inodecache:
1010 befs_destroy_inodecache();
1011
1012unacquire_none:
1013 return err;
1014}
1015
1016static void __exit
1017exit_befs_fs(void)
1018{
1019 befs_destroy_inodecache();
1020
1021 unregister_filesystem(&befs_fs_type);
1022}
1023
1024/*
1025 * Macros that typecheck the init and exit functions,
1026 * ensures that they are called at init and cleanup,
1027 * and eliminates warnings about unused functions.
1028 */
1029module_init(init_befs_fs)
1030module_exit(exit_befs_fs)