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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#include <linux/cred.h>
22#include <linux/exportfs.h>
23#include <linux/seq_file.h>
24
25#include "befs.h"
26#include "btree.h"
27#include "inode.h"
28#include "datastream.h"
29#include "super.h"
30#include "io.h"
31
32MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
33MODULE_AUTHOR("Will Dyson");
34MODULE_LICENSE("GPL");
35
36/* The units the vfs expects inode->i_blocks to be in */
37#define VFS_BLOCK_SIZE 512
38
39static int befs_readdir(struct file *, struct dir_context *);
40static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
41static int befs_readpage(struct file *file, struct page *page);
42static sector_t befs_bmap(struct address_space *mapping, sector_t block);
43static struct dentry *befs_lookup(struct inode *, struct dentry *,
44 unsigned int);
45static struct inode *befs_iget(struct super_block *, unsigned long);
46static struct inode *befs_alloc_inode(struct super_block *sb);
47static void befs_destroy_inode(struct inode *inode);
48static void befs_destroy_inodecache(void);
49static int befs_symlink_readpage(struct file *, struct page *);
50static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
51 char **out, int *out_len);
52static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
53 char **out, int *out_len);
54static void befs_put_super(struct super_block *);
55static int befs_remount(struct super_block *, int *, char *);
56static int befs_statfs(struct dentry *, struct kstatfs *);
57static int befs_show_options(struct seq_file *, struct dentry *);
58static int parse_options(char *, struct befs_mount_options *);
59static struct dentry *befs_fh_to_dentry(struct super_block *sb,
60 struct fid *fid, int fh_len, int fh_type);
61static struct dentry *befs_fh_to_parent(struct super_block *sb,
62 struct fid *fid, int fh_len, int fh_type);
63static struct dentry *befs_get_parent(struct dentry *child);
64
65static const struct super_operations befs_sops = {
66 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
67 .destroy_inode = befs_destroy_inode, /* deallocate an inode */
68 .put_super = befs_put_super, /* uninit super */
69 .statfs = befs_statfs, /* statfs */
70 .remount_fs = befs_remount,
71 .show_options = befs_show_options,
72};
73
74/* slab cache for befs_inode_info objects */
75static struct kmem_cache *befs_inode_cachep;
76
77static const struct file_operations befs_dir_operations = {
78 .read = generic_read_dir,
79 .iterate_shared = befs_readdir,
80 .llseek = generic_file_llseek,
81};
82
83static const struct inode_operations befs_dir_inode_operations = {
84 .lookup = befs_lookup,
85};
86
87static const struct address_space_operations befs_aops = {
88 .readpage = befs_readpage,
89 .bmap = befs_bmap,
90};
91
92static const struct address_space_operations befs_symlink_aops = {
93 .readpage = befs_symlink_readpage,
94};
95
96static const struct export_operations befs_export_operations = {
97 .fh_to_dentry = befs_fh_to_dentry,
98 .fh_to_parent = befs_fh_to_parent,
99 .get_parent = befs_get_parent,
100};
101
102/*
103 * Called by generic_file_read() to read a page of data
104 *
105 * In turn, simply calls a generic block read function and
106 * passes it the address of befs_get_block, for mapping file
107 * positions to disk blocks.
108 */
109static int
110befs_readpage(struct file *file, struct page *page)
111{
112 return block_read_full_page(page, befs_get_block);
113}
114
115static sector_t
116befs_bmap(struct address_space *mapping, sector_t block)
117{
118 return generic_block_bmap(mapping, block, befs_get_block);
119}
120
121/*
122 * Generic function to map a file position (block) to a
123 * disk offset (passed back in bh_result).
124 *
125 * Used by many higher level functions.
126 *
127 * Calls befs_fblock2brun() in datastream.c to do the real work.
128 */
129
130static int
131befs_get_block(struct inode *inode, sector_t block,
132 struct buffer_head *bh_result, int create)
133{
134 struct super_block *sb = inode->i_sb;
135 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
136 befs_block_run run = BAD_IADDR;
137 int res;
138 ulong disk_off;
139
140 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
141 (unsigned long)inode->i_ino, (long)block);
142 if (create) {
143 befs_error(sb, "befs_get_block() was asked to write to "
144 "block %ld in inode %lu", (long)block,
145 (unsigned long)inode->i_ino);
146 return -EPERM;
147 }
148
149 res = befs_fblock2brun(sb, ds, block, &run);
150 if (res != BEFS_OK) {
151 befs_error(sb,
152 "<--- %s for inode %lu, block %ld ERROR",
153 __func__, (unsigned long)inode->i_ino,
154 (long)block);
155 return -EFBIG;
156 }
157
158 disk_off = (ulong) iaddr2blockno(sb, &run);
159
160 map_bh(bh_result, inode->i_sb, disk_off);
161
162 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
163 __func__, (unsigned long)inode->i_ino, (long)block,
164 (unsigned long)disk_off);
165
166 return 0;
167}
168
169static struct dentry *
170befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
171{
172 struct inode *inode;
173 struct super_block *sb = dir->i_sb;
174 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
175 befs_off_t offset;
176 int ret;
177 int utfnamelen;
178 char *utfname;
179 const char *name = dentry->d_name.name;
180
181 befs_debug(sb, "---> %s name %pd inode %ld", __func__,
182 dentry, dir->i_ino);
183
184 /* Convert to UTF-8 */
185 if (BEFS_SB(sb)->nls) {
186 ret =
187 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
188 if (ret < 0) {
189 befs_debug(sb, "<--- %s ERROR", __func__);
190 return ERR_PTR(ret);
191 }
192 ret = befs_btree_find(sb, ds, utfname, &offset);
193 kfree(utfname);
194
195 } else {
196 ret = befs_btree_find(sb, ds, name, &offset);
197 }
198
199 if (ret == BEFS_BT_NOT_FOUND) {
200 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
201 inode = NULL;
202 } else if (ret != BEFS_OK || offset == 0) {
203 befs_error(sb, "<--- %s Error", __func__);
204 inode = ERR_PTR(-ENODATA);
205 } else {
206 inode = befs_iget(dir->i_sb, (ino_t) offset);
207 }
208 befs_debug(sb, "<--- %s", __func__);
209
210 return d_splice_alias(inode, dentry);
211}
212
213static int
214befs_readdir(struct file *file, struct dir_context *ctx)
215{
216 struct inode *inode = file_inode(file);
217 struct super_block *sb = inode->i_sb;
218 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
219 befs_off_t value;
220 int result;
221 size_t keysize;
222 char keybuf[BEFS_NAME_LEN + 1];
223
224 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
225 __func__, file, inode->i_ino, ctx->pos);
226
227 while (1) {
228 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
229 keybuf, &keysize, &value);
230
231 if (result == BEFS_ERR) {
232 befs_debug(sb, "<--- %s ERROR", __func__);
233 befs_error(sb, "IO error reading %pD (inode %lu)",
234 file, inode->i_ino);
235 return -EIO;
236
237 } else if (result == BEFS_BT_END) {
238 befs_debug(sb, "<--- %s END", __func__);
239 return 0;
240
241 } else if (result == BEFS_BT_EMPTY) {
242 befs_debug(sb, "<--- %s Empty directory", __func__);
243 return 0;
244 }
245
246 /* Convert to NLS */
247 if (BEFS_SB(sb)->nls) {
248 char *nlsname;
249 int nlsnamelen;
250
251 result =
252 befs_utf2nls(sb, keybuf, keysize, &nlsname,
253 &nlsnamelen);
254 if (result < 0) {
255 befs_debug(sb, "<--- %s ERROR", __func__);
256 return result;
257 }
258 if (!dir_emit(ctx, nlsname, nlsnamelen,
259 (ino_t) value, DT_UNKNOWN)) {
260 kfree(nlsname);
261 return 0;
262 }
263 kfree(nlsname);
264 } else {
265 if (!dir_emit(ctx, keybuf, keysize,
266 (ino_t) value, DT_UNKNOWN))
267 return 0;
268 }
269 ctx->pos++;
270 }
271}
272
273static struct inode *
274befs_alloc_inode(struct super_block *sb)
275{
276 struct befs_inode_info *bi;
277
278 bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
279 if (!bi)
280 return NULL;
281 return &bi->vfs_inode;
282}
283
284static void befs_i_callback(struct rcu_head *head)
285{
286 struct inode *inode = container_of(head, struct inode, i_rcu);
287 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
288}
289
290static void befs_destroy_inode(struct inode *inode)
291{
292 call_rcu(&inode->i_rcu, befs_i_callback);
293}
294
295static void init_once(void *foo)
296{
297 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
298
299 inode_init_once(&bi->vfs_inode);
300}
301
302static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
303{
304 struct buffer_head *bh;
305 befs_inode *raw_inode;
306 struct befs_sb_info *befs_sb = BEFS_SB(sb);
307 struct befs_inode_info *befs_ino;
308 struct inode *inode;
309
310 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
311
312 inode = iget_locked(sb, ino);
313 if (!inode)
314 return ERR_PTR(-ENOMEM);
315 if (!(inode->i_state & I_NEW))
316 return inode;
317
318 befs_ino = BEFS_I(inode);
319
320 /* convert from vfs's inode number to befs's inode number */
321 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
322
323 befs_debug(sb, " real inode number [%u, %hu, %hu]",
324 befs_ino->i_inode_num.allocation_group,
325 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
326
327 bh = sb_bread(sb, inode->i_ino);
328 if (!bh) {
329 befs_error(sb, "unable to read inode block - "
330 "inode = %lu", inode->i_ino);
331 goto unacquire_none;
332 }
333
334 raw_inode = (befs_inode *) bh->b_data;
335
336 befs_dump_inode(sb, raw_inode);
337
338 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
339 befs_error(sb, "Bad inode: %lu", inode->i_ino);
340 goto unacquire_bh;
341 }
342
343 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
344
345 /*
346 * set uid and gid. But since current BeOS is single user OS, so
347 * you can change by "uid" or "gid" options.
348 */
349
350 inode->i_uid = befs_sb->mount_opts.use_uid ?
351 befs_sb->mount_opts.uid :
352 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
353 inode->i_gid = befs_sb->mount_opts.use_gid ?
354 befs_sb->mount_opts.gid :
355 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
356
357 set_nlink(inode, 1);
358
359 /*
360 * BEFS's time is 64 bits, but current VFS is 32 bits...
361 * BEFS don't have access time. Nor inode change time. VFS
362 * doesn't have creation time.
363 * Also, the lower 16 bits of the last_modified_time and
364 * create_time are just a counter to help ensure uniqueness
365 * for indexing purposes. (PFD, page 54)
366 */
367
368 inode->i_mtime.tv_sec =
369 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
370 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
371 inode->i_ctime = inode->i_mtime;
372 inode->i_atime = inode->i_mtime;
373
374 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
375 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
376 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
377 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
378
379 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
380 inode->i_size = 0;
381 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
382 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
383 BEFS_SYMLINK_LEN);
384 } else {
385 int num_blks;
386
387 befs_ino->i_data.ds =
388 fsds_to_cpu(sb, &raw_inode->data.datastream);
389
390 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
391 inode->i_blocks =
392 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
393 inode->i_size = befs_ino->i_data.ds.size;
394 }
395
396 inode->i_mapping->a_ops = &befs_aops;
397
398 if (S_ISREG(inode->i_mode)) {
399 inode->i_fop = &generic_ro_fops;
400 } else if (S_ISDIR(inode->i_mode)) {
401 inode->i_op = &befs_dir_inode_operations;
402 inode->i_fop = &befs_dir_operations;
403 } else if (S_ISLNK(inode->i_mode)) {
404 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
405 inode->i_op = &page_symlink_inode_operations;
406 inode_nohighmem(inode);
407 inode->i_mapping->a_ops = &befs_symlink_aops;
408 } else {
409 inode->i_link = befs_ino->i_data.symlink;
410 inode->i_op = &simple_symlink_inode_operations;
411 }
412 } else {
413 befs_error(sb, "Inode %lu is not a regular file, "
414 "directory or symlink. THAT IS WRONG! BeFS has no "
415 "on disk special files", inode->i_ino);
416 goto unacquire_bh;
417 }
418
419 brelse(bh);
420 befs_debug(sb, "<--- %s", __func__);
421 unlock_new_inode(inode);
422 return inode;
423
424unacquire_bh:
425 brelse(bh);
426
427unacquire_none:
428 iget_failed(inode);
429 befs_debug(sb, "<--- %s - Bad inode", __func__);
430 return ERR_PTR(-EIO);
431}
432
433/* Initialize the inode cache. Called at fs setup.
434 *
435 * Taken from NFS implementation by Al Viro.
436 */
437static int __init
438befs_init_inodecache(void)
439{
440 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
441 sizeof(struct befs_inode_info), 0,
442 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
443 SLAB_ACCOUNT),
444 offsetof(struct befs_inode_info,
445 i_data.symlink),
446 sizeof_field(struct befs_inode_info,
447 i_data.symlink),
448 init_once);
449 if (befs_inode_cachep == NULL)
450 return -ENOMEM;
451
452 return 0;
453}
454
455/* Called at fs teardown.
456 *
457 * Taken from NFS implementation by Al Viro.
458 */
459static void
460befs_destroy_inodecache(void)
461{
462 /*
463 * Make sure all delayed rcu free inodes are flushed before we
464 * destroy cache.
465 */
466 rcu_barrier();
467 kmem_cache_destroy(befs_inode_cachep);
468}
469
470/*
471 * The inode of symbolic link is different to data stream.
472 * The data stream become link name. Unless the LONG_SYMLINK
473 * flag is set.
474 */
475static int befs_symlink_readpage(struct file *unused, struct page *page)
476{
477 struct inode *inode = page->mapping->host;
478 struct super_block *sb = inode->i_sb;
479 struct befs_inode_info *befs_ino = BEFS_I(inode);
480 befs_data_stream *data = &befs_ino->i_data.ds;
481 befs_off_t len = data->size;
482 char *link = page_address(page);
483
484 if (len == 0 || len > PAGE_SIZE) {
485 befs_error(sb, "Long symlink with illegal length");
486 goto fail;
487 }
488 befs_debug(sb, "Follow long symlink");
489
490 if (befs_read_lsymlink(sb, data, link, len) != len) {
491 befs_error(sb, "Failed to read entire long symlink");
492 goto fail;
493 }
494 link[len - 1] = '\0';
495 SetPageUptodate(page);
496 unlock_page(page);
497 return 0;
498fail:
499 SetPageError(page);
500 unlock_page(page);
501 return -EIO;
502}
503
504/*
505 * UTF-8 to NLS charset convert routine
506 *
507 * Uses uni2char() / char2uni() rather than the nls tables directly
508 */
509static int
510befs_utf2nls(struct super_block *sb, const char *in,
511 int in_len, char **out, int *out_len)
512{
513 struct nls_table *nls = BEFS_SB(sb)->nls;
514 int i, o;
515 unicode_t uni;
516 int unilen, utflen;
517 char *result;
518 /* The utf8->nls conversion won't make the final nls string bigger
519 * than the utf one, but if the string is pure ascii they'll have the
520 * same width and an extra char is needed to save the additional \0
521 */
522 int maxlen = in_len + 1;
523
524 befs_debug(sb, "---> %s", __func__);
525
526 if (!nls) {
527 befs_error(sb, "%s called with no NLS table loaded", __func__);
528 return -EINVAL;
529 }
530
531 *out = result = kmalloc(maxlen, GFP_NOFS);
532 if (!*out)
533 return -ENOMEM;
534
535 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
536
537 /* convert from UTF-8 to Unicode */
538 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
539 if (utflen < 0)
540 goto conv_err;
541
542 /* convert from Unicode to nls */
543 if (uni > MAX_WCHAR_T)
544 goto conv_err;
545 unilen = nls->uni2char(uni, &result[o], in_len - o);
546 if (unilen < 0)
547 goto conv_err;
548 }
549 result[o] = '\0';
550 *out_len = o;
551
552 befs_debug(sb, "<--- %s", __func__);
553
554 return o;
555
556conv_err:
557 befs_error(sb, "Name using character set %s contains a character that "
558 "cannot be converted to unicode.", nls->charset);
559 befs_debug(sb, "<--- %s", __func__);
560 kfree(result);
561 return -EILSEQ;
562}
563
564/**
565 * befs_nls2utf - Convert NLS string to utf8 encodeing
566 * @sb: Superblock
567 * @in: Input string buffer in NLS format
568 * @in_len: Length of input string in bytes
569 * @out: The output string in UTF-8 format
570 * @out_len: Length of the output buffer
571 *
572 * Converts input string @in, which is in the format of the loaded NLS map,
573 * into a utf8 string.
574 *
575 * The destination string @out is allocated by this function and the caller is
576 * responsible for freeing it with kfree()
577 *
578 * On return, *@out_len is the length of @out in bytes.
579 *
580 * On success, the return value is the number of utf8 characters written to
581 * the output buffer @out.
582 *
583 * On Failure, a negative number coresponding to the error code is returned.
584 */
585
586static int
587befs_nls2utf(struct super_block *sb, const char *in,
588 int in_len, char **out, int *out_len)
589{
590 struct nls_table *nls = BEFS_SB(sb)->nls;
591 int i, o;
592 wchar_t uni;
593 int unilen, utflen;
594 char *result;
595 /*
596 * There are nls characters that will translate to 3-chars-wide UTF-8
597 * characters, an additional byte is needed to save the final \0
598 * in special cases
599 */
600 int maxlen = (3 * in_len) + 1;
601
602 befs_debug(sb, "---> %s\n", __func__);
603
604 if (!nls) {
605 befs_error(sb, "%s called with no NLS table loaded.",
606 __func__);
607 return -EINVAL;
608 }
609
610 *out = result = kmalloc(maxlen, GFP_NOFS);
611 if (!*out) {
612 *out_len = 0;
613 return -ENOMEM;
614 }
615
616 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
617
618 /* convert from nls to unicode */
619 unilen = nls->char2uni(&in[i], in_len - i, &uni);
620 if (unilen < 0)
621 goto conv_err;
622
623 /* convert from unicode to UTF-8 */
624 utflen = utf32_to_utf8(uni, &result[o], 3);
625 if (utflen <= 0)
626 goto conv_err;
627 }
628
629 result[o] = '\0';
630 *out_len = o;
631
632 befs_debug(sb, "<--- %s", __func__);
633
634 return i;
635
636conv_err:
637 befs_error(sb, "Name using character set %s contains a character that "
638 "cannot be converted to unicode.", nls->charset);
639 befs_debug(sb, "<--- %s", __func__);
640 kfree(result);
641 return -EILSEQ;
642}
643
644static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
645 uint32_t generation)
646{
647 /* No need to handle i_generation */
648 return befs_iget(sb, ino);
649}
650
651/*
652 * Map a NFS file handle to a corresponding dentry
653 */
654static struct dentry *befs_fh_to_dentry(struct super_block *sb,
655 struct fid *fid, int fh_len, int fh_type)
656{
657 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
658 befs_nfs_get_inode);
659}
660
661/*
662 * Find the parent for a file specified by NFS handle
663 */
664static struct dentry *befs_fh_to_parent(struct super_block *sb,
665 struct fid *fid, int fh_len, int fh_type)
666{
667 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
668 befs_nfs_get_inode);
669}
670
671static struct dentry *befs_get_parent(struct dentry *child)
672{
673 struct inode *parent;
674 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
675
676 parent = befs_iget(child->d_sb,
677 (unsigned long)befs_ino->i_parent.start);
678 if (IS_ERR(parent))
679 return ERR_CAST(parent);
680
681 return d_obtain_alias(parent);
682}
683
684enum {
685 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
686};
687
688static const match_table_t befs_tokens = {
689 {Opt_uid, "uid=%d"},
690 {Opt_gid, "gid=%d"},
691 {Opt_charset, "iocharset=%s"},
692 {Opt_debug, "debug"},
693 {Opt_err, NULL}
694};
695
696static int
697parse_options(char *options, struct befs_mount_options *opts)
698{
699 char *p;
700 substring_t args[MAX_OPT_ARGS];
701 int option;
702 kuid_t uid;
703 kgid_t gid;
704
705 /* Initialize options */
706 opts->uid = GLOBAL_ROOT_UID;
707 opts->gid = GLOBAL_ROOT_GID;
708 opts->use_uid = 0;
709 opts->use_gid = 0;
710 opts->iocharset = NULL;
711 opts->debug = 0;
712
713 if (!options)
714 return 1;
715
716 while ((p = strsep(&options, ",")) != NULL) {
717 int token;
718
719 if (!*p)
720 continue;
721
722 token = match_token(p, befs_tokens, args);
723 switch (token) {
724 case Opt_uid:
725 if (match_int(&args[0], &option))
726 return 0;
727 uid = INVALID_UID;
728 if (option >= 0)
729 uid = make_kuid(current_user_ns(), option);
730 if (!uid_valid(uid)) {
731 pr_err("Invalid uid %d, "
732 "using default\n", option);
733 break;
734 }
735 opts->uid = uid;
736 opts->use_uid = 1;
737 break;
738 case Opt_gid:
739 if (match_int(&args[0], &option))
740 return 0;
741 gid = INVALID_GID;
742 if (option >= 0)
743 gid = make_kgid(current_user_ns(), option);
744 if (!gid_valid(gid)) {
745 pr_err("Invalid gid %d, "
746 "using default\n", option);
747 break;
748 }
749 opts->gid = gid;
750 opts->use_gid = 1;
751 break;
752 case Opt_charset:
753 kfree(opts->iocharset);
754 opts->iocharset = match_strdup(&args[0]);
755 if (!opts->iocharset) {
756 pr_err("allocation failure for "
757 "iocharset string\n");
758 return 0;
759 }
760 break;
761 case Opt_debug:
762 opts->debug = 1;
763 break;
764 default:
765 pr_err("Unrecognized mount option \"%s\" "
766 "or missing value\n", p);
767 return 0;
768 }
769 }
770 return 1;
771}
772
773static int befs_show_options(struct seq_file *m, struct dentry *root)
774{
775 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
776 struct befs_mount_options *opts = &befs_sb->mount_opts;
777
778 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
779 seq_printf(m, ",uid=%u",
780 from_kuid_munged(&init_user_ns, opts->uid));
781 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
782 seq_printf(m, ",gid=%u",
783 from_kgid_munged(&init_user_ns, opts->gid));
784 if (opts->iocharset)
785 seq_printf(m, ",charset=%s", opts->iocharset);
786 if (opts->debug)
787 seq_puts(m, ",debug");
788 return 0;
789}
790
791/* This function has the responsibiltiy of getting the
792 * filesystem ready for unmounting.
793 * Basically, we free everything that we allocated in
794 * befs_read_inode
795 */
796static void
797befs_put_super(struct super_block *sb)
798{
799 kfree(BEFS_SB(sb)->mount_opts.iocharset);
800 BEFS_SB(sb)->mount_opts.iocharset = NULL;
801 unload_nls(BEFS_SB(sb)->nls);
802 kfree(sb->s_fs_info);
803 sb->s_fs_info = NULL;
804}
805
806/* Allocate private field of the superblock, fill it.
807 *
808 * Finish filling the public superblock fields
809 * Make the root directory
810 * Load a set of NLS translations if needed.
811 */
812static int
813befs_fill_super(struct super_block *sb, void *data, int silent)
814{
815 struct buffer_head *bh;
816 struct befs_sb_info *befs_sb;
817 befs_super_block *disk_sb;
818 struct inode *root;
819 long ret = -EINVAL;
820 const unsigned long sb_block = 0;
821 const off_t x86_sb_off = 512;
822 int blocksize;
823
824 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
825 if (sb->s_fs_info == NULL)
826 goto unacquire_none;
827
828 befs_sb = BEFS_SB(sb);
829
830 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
831 if (!silent)
832 befs_error(sb, "cannot parse mount options");
833 goto unacquire_priv_sbp;
834 }
835
836 befs_debug(sb, "---> %s", __func__);
837
838 if (!sb_rdonly(sb)) {
839 befs_warning(sb,
840 "No write support. Marking filesystem read-only");
841 sb->s_flags |= SB_RDONLY;
842 }
843
844 /*
845 * Set dummy blocksize to read super block.
846 * Will be set to real fs blocksize later.
847 *
848 * Linux 2.4.10 and later refuse to read blocks smaller than
849 * the logical block size for the device. But we also need to read at
850 * least 1k to get the second 512 bytes of the volume.
851 */
852 blocksize = sb_min_blocksize(sb, 1024);
853 if (!blocksize) {
854 if (!silent)
855 befs_error(sb, "unable to set blocksize");
856 goto unacquire_priv_sbp;
857 }
858
859 bh = sb_bread(sb, sb_block);
860 if (!bh) {
861 if (!silent)
862 befs_error(sb, "unable to read superblock");
863 goto unacquire_priv_sbp;
864 }
865
866 /* account for offset of super block on x86 */
867 disk_sb = (befs_super_block *) bh->b_data;
868 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
869 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
870 befs_debug(sb, "Using PPC superblock location");
871 } else {
872 befs_debug(sb, "Using x86 superblock location");
873 disk_sb =
874 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
875 }
876
877 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
878 (befs_check_sb(sb) != BEFS_OK))
879 goto unacquire_bh;
880
881 befs_dump_super_block(sb, disk_sb);
882
883 brelse(bh);
884
885 if (befs_sb->num_blocks > ~((sector_t)0)) {
886 if (!silent)
887 befs_error(sb, "blocks count: %llu is larger than the host can use",
888 befs_sb->num_blocks);
889 goto unacquire_priv_sbp;
890 }
891
892 /*
893 * set up enough so that it can read an inode
894 * Fill in kernel superblock fields from private sb
895 */
896 sb->s_magic = BEFS_SUPER_MAGIC;
897 /* Set real blocksize of fs */
898 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
899 sb->s_op = &befs_sops;
900 sb->s_export_op = &befs_export_operations;
901 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
902 if (IS_ERR(root)) {
903 ret = PTR_ERR(root);
904 goto unacquire_priv_sbp;
905 }
906 sb->s_root = d_make_root(root);
907 if (!sb->s_root) {
908 if (!silent)
909 befs_error(sb, "get root inode failed");
910 goto unacquire_priv_sbp;
911 }
912
913 /* load nls library */
914 if (befs_sb->mount_opts.iocharset) {
915 befs_debug(sb, "Loading nls: %s",
916 befs_sb->mount_opts.iocharset);
917 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
918 if (!befs_sb->nls) {
919 befs_warning(sb, "Cannot load nls %s"
920 " loading default nls",
921 befs_sb->mount_opts.iocharset);
922 befs_sb->nls = load_nls_default();
923 }
924 /* load default nls if none is specified in mount options */
925 } else {
926 befs_debug(sb, "Loading default nls");
927 befs_sb->nls = load_nls_default();
928 }
929
930 return 0;
931
932unacquire_bh:
933 brelse(bh);
934
935unacquire_priv_sbp:
936 kfree(befs_sb->mount_opts.iocharset);
937 kfree(sb->s_fs_info);
938 sb->s_fs_info = NULL;
939
940unacquire_none:
941 return ret;
942}
943
944static int
945befs_remount(struct super_block *sb, int *flags, char *data)
946{
947 sync_filesystem(sb);
948 if (!(*flags & SB_RDONLY))
949 return -EINVAL;
950 return 0;
951}
952
953static int
954befs_statfs(struct dentry *dentry, struct kstatfs *buf)
955{
956 struct super_block *sb = dentry->d_sb;
957 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
958
959 befs_debug(sb, "---> %s", __func__);
960
961 buf->f_type = BEFS_SUPER_MAGIC;
962 buf->f_bsize = sb->s_blocksize;
963 buf->f_blocks = BEFS_SB(sb)->num_blocks;
964 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
965 buf->f_bavail = buf->f_bfree;
966 buf->f_files = 0; /* UNKNOWN */
967 buf->f_ffree = 0; /* UNKNOWN */
968 buf->f_fsid.val[0] = (u32)id;
969 buf->f_fsid.val[1] = (u32)(id >> 32);
970 buf->f_namelen = BEFS_NAME_LEN;
971
972 befs_debug(sb, "<--- %s", __func__);
973
974 return 0;
975}
976
977static struct dentry *
978befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
979 void *data)
980{
981 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
982}
983
984static struct file_system_type befs_fs_type = {
985 .owner = THIS_MODULE,
986 .name = "befs",
987 .mount = befs_mount,
988 .kill_sb = kill_block_super,
989 .fs_flags = FS_REQUIRES_DEV,
990};
991MODULE_ALIAS_FS("befs");
992
993static int __init
994init_befs_fs(void)
995{
996 int err;
997
998 pr_info("version: %s\n", BEFS_VERSION);
999
1000 err = befs_init_inodecache();
1001 if (err)
1002 goto unacquire_none;
1003
1004 err = register_filesystem(&befs_fs_type);
1005 if (err)
1006 goto unacquire_inodecache;
1007
1008 return 0;
1009
1010unacquire_inodecache:
1011 befs_destroy_inodecache();
1012
1013unacquire_none:
1014 return err;
1015}
1016
1017static void __exit
1018exit_befs_fs(void)
1019{
1020 befs_destroy_inodecache();
1021
1022 unregister_filesystem(&befs_fs_type);
1023}
1024
1025/*
1026 * Macros that typecheck the init and exit functions,
1027 * ensures that they are called at init and cleanup,
1028 * and eliminates warnings about unused functions.
1029 */
1030module_init(init_befs_fs)
1031module_exit(exit_befs_fs)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/befs/linuxvfs.c
4 *
5 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
6 *
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/fs.h>
14#include <linux/errno.h>
15#include <linux/stat.h>
16#include <linux/nls.h>
17#include <linux/buffer_head.h>
18#include <linux/vfs.h>
19#include <linux/parser.h>
20#include <linux/namei.h>
21#include <linux/sched.h>
22#include <linux/cred.h>
23#include <linux/exportfs.h>
24#include <linux/seq_file.h>
25#include <linux/blkdev.h>
26
27#include "befs.h"
28#include "btree.h"
29#include "inode.h"
30#include "datastream.h"
31#include "super.h"
32#include "io.h"
33
34MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
35MODULE_AUTHOR("Will Dyson");
36MODULE_LICENSE("GPL");
37
38/* The units the vfs expects inode->i_blocks to be in */
39#define VFS_BLOCK_SIZE 512
40
41static int befs_readdir(struct file *, struct dir_context *);
42static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
43static int befs_read_folio(struct file *file, struct folio *folio);
44static sector_t befs_bmap(struct address_space *mapping, sector_t block);
45static struct dentry *befs_lookup(struct inode *, struct dentry *,
46 unsigned int);
47static struct inode *befs_iget(struct super_block *, unsigned long);
48static struct inode *befs_alloc_inode(struct super_block *sb);
49static void befs_free_inode(struct inode *inode);
50static void befs_destroy_inodecache(void);
51static int befs_symlink_read_folio(struct file *, struct folio *);
52static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
53 char **out, int *out_len);
54static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
55 char **out, int *out_len);
56static void befs_put_super(struct super_block *);
57static int befs_remount(struct super_block *, int *, char *);
58static int befs_statfs(struct dentry *, struct kstatfs *);
59static int befs_show_options(struct seq_file *, struct dentry *);
60static int parse_options(char *, struct befs_mount_options *);
61static struct dentry *befs_fh_to_dentry(struct super_block *sb,
62 struct fid *fid, int fh_len, int fh_type);
63static struct dentry *befs_fh_to_parent(struct super_block *sb,
64 struct fid *fid, int fh_len, int fh_type);
65static struct dentry *befs_get_parent(struct dentry *child);
66
67static const struct super_operations befs_sops = {
68 .alloc_inode = befs_alloc_inode, /* allocate a new inode */
69 .free_inode = befs_free_inode, /* deallocate an inode */
70 .put_super = befs_put_super, /* uninit super */
71 .statfs = befs_statfs, /* statfs */
72 .remount_fs = befs_remount,
73 .show_options = befs_show_options,
74};
75
76/* slab cache for befs_inode_info objects */
77static struct kmem_cache *befs_inode_cachep;
78
79static const struct file_operations befs_dir_operations = {
80 .read = generic_read_dir,
81 .iterate_shared = befs_readdir,
82 .llseek = generic_file_llseek,
83};
84
85static const struct inode_operations befs_dir_inode_operations = {
86 .lookup = befs_lookup,
87};
88
89static const struct address_space_operations befs_aops = {
90 .read_folio = befs_read_folio,
91 .bmap = befs_bmap,
92};
93
94static const struct address_space_operations befs_symlink_aops = {
95 .read_folio = befs_symlink_read_folio,
96};
97
98static const struct export_operations befs_export_operations = {
99 .fh_to_dentry = befs_fh_to_dentry,
100 .fh_to_parent = befs_fh_to_parent,
101 .get_parent = befs_get_parent,
102};
103
104/*
105 * Called by generic_file_read() to read a folio of data
106 *
107 * In turn, simply calls a generic block read function and
108 * passes it the address of befs_get_block, for mapping file
109 * positions to disk blocks.
110 */
111static int befs_read_folio(struct file *file, struct folio *folio)
112{
113 return block_read_full_folio(folio, befs_get_block);
114}
115
116static sector_t
117befs_bmap(struct address_space *mapping, sector_t block)
118{
119 return generic_block_bmap(mapping, block, befs_get_block);
120}
121
122/*
123 * Generic function to map a file position (block) to a
124 * disk offset (passed back in bh_result).
125 *
126 * Used by many higher level functions.
127 *
128 * Calls befs_fblock2brun() in datastream.c to do the real work.
129 */
130
131static int
132befs_get_block(struct inode *inode, sector_t block,
133 struct buffer_head *bh_result, int create)
134{
135 struct super_block *sb = inode->i_sb;
136 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
137 befs_block_run run = BAD_IADDR;
138 int res;
139 ulong disk_off;
140
141 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
142 (unsigned long)inode->i_ino, (long)block);
143 if (create) {
144 befs_error(sb, "befs_get_block() was asked to write to "
145 "block %ld in inode %lu", (long)block,
146 (unsigned long)inode->i_ino);
147 return -EPERM;
148 }
149
150 res = befs_fblock2brun(sb, ds, block, &run);
151 if (res != BEFS_OK) {
152 befs_error(sb,
153 "<--- %s for inode %lu, block %ld ERROR",
154 __func__, (unsigned long)inode->i_ino,
155 (long)block);
156 return -EFBIG;
157 }
158
159 disk_off = (ulong) iaddr2blockno(sb, &run);
160
161 map_bh(bh_result, inode->i_sb, disk_off);
162
163 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
164 __func__, (unsigned long)inode->i_ino, (long)block,
165 (unsigned long)disk_off);
166
167 return 0;
168}
169
170static struct dentry *
171befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
172{
173 struct inode *inode;
174 struct super_block *sb = dir->i_sb;
175 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
176 befs_off_t offset;
177 int ret;
178 int utfnamelen;
179 char *utfname;
180 const char *name = dentry->d_name.name;
181
182 befs_debug(sb, "---> %s name %pd inode %ld", __func__,
183 dentry, dir->i_ino);
184
185 /* Convert to UTF-8 */
186 if (BEFS_SB(sb)->nls) {
187 ret =
188 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
189 if (ret < 0) {
190 befs_debug(sb, "<--- %s ERROR", __func__);
191 return ERR_PTR(ret);
192 }
193 ret = befs_btree_find(sb, ds, utfname, &offset);
194 kfree(utfname);
195
196 } else {
197 ret = befs_btree_find(sb, ds, name, &offset);
198 }
199
200 if (ret == BEFS_BT_NOT_FOUND) {
201 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
202 inode = NULL;
203 } else if (ret != BEFS_OK || offset == 0) {
204 befs_error(sb, "<--- %s Error", __func__);
205 inode = ERR_PTR(-ENODATA);
206 } else {
207 inode = befs_iget(dir->i_sb, (ino_t) offset);
208 }
209 befs_debug(sb, "<--- %s", __func__);
210
211 return d_splice_alias(inode, dentry);
212}
213
214static int
215befs_readdir(struct file *file, struct dir_context *ctx)
216{
217 struct inode *inode = file_inode(file);
218 struct super_block *sb = inode->i_sb;
219 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
220 befs_off_t value;
221 int result;
222 size_t keysize;
223 char keybuf[BEFS_NAME_LEN + 1];
224
225 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
226 __func__, file, inode->i_ino, ctx->pos);
227
228 while (1) {
229 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
230 keybuf, &keysize, &value);
231
232 if (result == BEFS_ERR) {
233 befs_debug(sb, "<--- %s ERROR", __func__);
234 befs_error(sb, "IO error reading %pD (inode %lu)",
235 file, inode->i_ino);
236 return -EIO;
237
238 } else if (result == BEFS_BT_END) {
239 befs_debug(sb, "<--- %s END", __func__);
240 return 0;
241
242 } else if (result == BEFS_BT_EMPTY) {
243 befs_debug(sb, "<--- %s Empty directory", __func__);
244 return 0;
245 }
246
247 /* Convert to NLS */
248 if (BEFS_SB(sb)->nls) {
249 char *nlsname;
250 int nlsnamelen;
251
252 result =
253 befs_utf2nls(sb, keybuf, keysize, &nlsname,
254 &nlsnamelen);
255 if (result < 0) {
256 befs_debug(sb, "<--- %s ERROR", __func__);
257 return result;
258 }
259 if (!dir_emit(ctx, nlsname, nlsnamelen,
260 (ino_t) value, DT_UNKNOWN)) {
261 kfree(nlsname);
262 return 0;
263 }
264 kfree(nlsname);
265 } else {
266 if (!dir_emit(ctx, keybuf, keysize,
267 (ino_t) value, DT_UNKNOWN))
268 return 0;
269 }
270 ctx->pos++;
271 }
272}
273
274static struct inode *
275befs_alloc_inode(struct super_block *sb)
276{
277 struct befs_inode_info *bi;
278
279 bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL);
280 if (!bi)
281 return NULL;
282 return &bi->vfs_inode;
283}
284
285static void befs_free_inode(struct inode *inode)
286{
287 kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
288}
289
290static void init_once(void *foo)
291{
292 struct befs_inode_info *bi = (struct befs_inode_info *) foo;
293
294 inode_init_once(&bi->vfs_inode);
295}
296
297static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
298{
299 struct buffer_head *bh;
300 befs_inode *raw_inode;
301 struct befs_sb_info *befs_sb = BEFS_SB(sb);
302 struct befs_inode_info *befs_ino;
303 struct inode *inode;
304
305 befs_debug(sb, "---> %s inode = %lu", __func__, ino);
306
307 inode = iget_locked(sb, ino);
308 if (!inode)
309 return ERR_PTR(-ENOMEM);
310 if (!(inode->i_state & I_NEW))
311 return inode;
312
313 befs_ino = BEFS_I(inode);
314
315 /* convert from vfs's inode number to befs's inode number */
316 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
317
318 befs_debug(sb, " real inode number [%u, %hu, %hu]",
319 befs_ino->i_inode_num.allocation_group,
320 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
321
322 bh = sb_bread(sb, inode->i_ino);
323 if (!bh) {
324 befs_error(sb, "unable to read inode block - "
325 "inode = %lu", inode->i_ino);
326 goto unacquire_none;
327 }
328
329 raw_inode = (befs_inode *) bh->b_data;
330
331 befs_dump_inode(sb, raw_inode);
332
333 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
334 befs_error(sb, "Bad inode: %lu", inode->i_ino);
335 goto unacquire_bh;
336 }
337
338 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
339
340 /*
341 * set uid and gid. But since current BeOS is single user OS, so
342 * you can change by "uid" or "gid" options.
343 */
344
345 inode->i_uid = befs_sb->mount_opts.use_uid ?
346 befs_sb->mount_opts.uid :
347 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
348 inode->i_gid = befs_sb->mount_opts.use_gid ?
349 befs_sb->mount_opts.gid :
350 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
351
352 set_nlink(inode, 1);
353
354 /*
355 * BEFS's time is 64 bits, but current VFS is 32 bits...
356 * BEFS don't have access time. Nor inode change time. VFS
357 * doesn't have creation time.
358 * Also, the lower 16 bits of the last_modified_time and
359 * create_time are just a counter to help ensure uniqueness
360 * for indexing purposes. (PFD, page 54)
361 */
362
363 inode->i_mtime.tv_sec =
364 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
365 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
366 inode->i_ctime = inode->i_mtime;
367 inode->i_atime = inode->i_mtime;
368
369 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
370 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
371 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
372 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
373
374 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
375 inode->i_size = 0;
376 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
377 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
378 BEFS_SYMLINK_LEN);
379 } else {
380 int num_blks;
381
382 befs_ino->i_data.ds =
383 fsds_to_cpu(sb, &raw_inode->data.datastream);
384
385 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
386 inode->i_blocks =
387 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
388 inode->i_size = befs_ino->i_data.ds.size;
389 }
390
391 inode->i_mapping->a_ops = &befs_aops;
392
393 if (S_ISREG(inode->i_mode)) {
394 inode->i_fop = &generic_ro_fops;
395 } else if (S_ISDIR(inode->i_mode)) {
396 inode->i_op = &befs_dir_inode_operations;
397 inode->i_fop = &befs_dir_operations;
398 } else if (S_ISLNK(inode->i_mode)) {
399 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
400 inode->i_op = &page_symlink_inode_operations;
401 inode_nohighmem(inode);
402 inode->i_mapping->a_ops = &befs_symlink_aops;
403 } else {
404 inode->i_link = befs_ino->i_data.symlink;
405 inode->i_op = &simple_symlink_inode_operations;
406 }
407 } else {
408 befs_error(sb, "Inode %lu is not a regular file, "
409 "directory or symlink. THAT IS WRONG! BeFS has no "
410 "on disk special files", inode->i_ino);
411 goto unacquire_bh;
412 }
413
414 brelse(bh);
415 befs_debug(sb, "<--- %s", __func__);
416 unlock_new_inode(inode);
417 return inode;
418
419unacquire_bh:
420 brelse(bh);
421
422unacquire_none:
423 iget_failed(inode);
424 befs_debug(sb, "<--- %s - Bad inode", __func__);
425 return ERR_PTR(-EIO);
426}
427
428/* Initialize the inode cache. Called at fs setup.
429 *
430 * Taken from NFS implementation by Al Viro.
431 */
432static int __init
433befs_init_inodecache(void)
434{
435 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
436 sizeof(struct befs_inode_info), 0,
437 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
438 SLAB_ACCOUNT),
439 offsetof(struct befs_inode_info,
440 i_data.symlink),
441 sizeof_field(struct befs_inode_info,
442 i_data.symlink),
443 init_once);
444 if (befs_inode_cachep == NULL)
445 return -ENOMEM;
446
447 return 0;
448}
449
450/* Called at fs teardown.
451 *
452 * Taken from NFS implementation by Al Viro.
453 */
454static void
455befs_destroy_inodecache(void)
456{
457 /*
458 * Make sure all delayed rcu free inodes are flushed before we
459 * destroy cache.
460 */
461 rcu_barrier();
462 kmem_cache_destroy(befs_inode_cachep);
463}
464
465/*
466 * The inode of symbolic link is different to data stream.
467 * The data stream become link name. Unless the LONG_SYMLINK
468 * flag is set.
469 */
470static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
471{
472 struct inode *inode = folio->mapping->host;
473 struct super_block *sb = inode->i_sb;
474 struct befs_inode_info *befs_ino = BEFS_I(inode);
475 befs_data_stream *data = &befs_ino->i_data.ds;
476 befs_off_t len = data->size;
477 char *link = folio_address(folio);
478
479 if (len == 0 || len > PAGE_SIZE) {
480 befs_error(sb, "Long symlink with illegal length");
481 goto fail;
482 }
483 befs_debug(sb, "Follow long symlink");
484
485 if (befs_read_lsymlink(sb, data, link, len) != len) {
486 befs_error(sb, "Failed to read entire long symlink");
487 goto fail;
488 }
489 link[len - 1] = '\0';
490 folio_mark_uptodate(folio);
491 folio_unlock(folio);
492 return 0;
493fail:
494 folio_set_error(folio);
495 folio_unlock(folio);
496 return -EIO;
497}
498
499/*
500 * UTF-8 to NLS charset convert routine
501 *
502 * Uses uni2char() / char2uni() rather than the nls tables directly
503 */
504static int
505befs_utf2nls(struct super_block *sb, const char *in,
506 int in_len, char **out, int *out_len)
507{
508 struct nls_table *nls = BEFS_SB(sb)->nls;
509 int i, o;
510 unicode_t uni;
511 int unilen, utflen;
512 char *result;
513 /* The utf8->nls conversion won't make the final nls string bigger
514 * than the utf one, but if the string is pure ascii they'll have the
515 * same width and an extra char is needed to save the additional \0
516 */
517 int maxlen = in_len + 1;
518
519 befs_debug(sb, "---> %s", __func__);
520
521 if (!nls) {
522 befs_error(sb, "%s called with no NLS table loaded", __func__);
523 return -EINVAL;
524 }
525
526 *out = result = kmalloc(maxlen, GFP_NOFS);
527 if (!*out)
528 return -ENOMEM;
529
530 for (i = o = 0; i < in_len; i += utflen, o += unilen) {
531
532 /* convert from UTF-8 to Unicode */
533 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
534 if (utflen < 0)
535 goto conv_err;
536
537 /* convert from Unicode to nls */
538 if (uni > MAX_WCHAR_T)
539 goto conv_err;
540 unilen = nls->uni2char(uni, &result[o], in_len - o);
541 if (unilen < 0)
542 goto conv_err;
543 }
544 result[o] = '\0';
545 *out_len = o;
546
547 befs_debug(sb, "<--- %s", __func__);
548
549 return o;
550
551conv_err:
552 befs_error(sb, "Name using character set %s contains a character that "
553 "cannot be converted to unicode.", nls->charset);
554 befs_debug(sb, "<--- %s", __func__);
555 kfree(result);
556 return -EILSEQ;
557}
558
559/**
560 * befs_nls2utf - Convert NLS string to utf8 encodeing
561 * @sb: Superblock
562 * @in: Input string buffer in NLS format
563 * @in_len: Length of input string in bytes
564 * @out: The output string in UTF-8 format
565 * @out_len: Length of the output buffer
566 *
567 * Converts input string @in, which is in the format of the loaded NLS map,
568 * into a utf8 string.
569 *
570 * The destination string @out is allocated by this function and the caller is
571 * responsible for freeing it with kfree()
572 *
573 * On return, *@out_len is the length of @out in bytes.
574 *
575 * On success, the return value is the number of utf8 characters written to
576 * the output buffer @out.
577 *
578 * On Failure, a negative number coresponding to the error code is returned.
579 */
580
581static int
582befs_nls2utf(struct super_block *sb, const char *in,
583 int in_len, char **out, int *out_len)
584{
585 struct nls_table *nls = BEFS_SB(sb)->nls;
586 int i, o;
587 wchar_t uni;
588 int unilen, utflen;
589 char *result;
590 /*
591 * There are nls characters that will translate to 3-chars-wide UTF-8
592 * characters, an additional byte is needed to save the final \0
593 * in special cases
594 */
595 int maxlen = (3 * in_len) + 1;
596
597 befs_debug(sb, "---> %s\n", __func__);
598
599 if (!nls) {
600 befs_error(sb, "%s called with no NLS table loaded.",
601 __func__);
602 return -EINVAL;
603 }
604
605 *out = result = kmalloc(maxlen, GFP_NOFS);
606 if (!*out) {
607 *out_len = 0;
608 return -ENOMEM;
609 }
610
611 for (i = o = 0; i < in_len; i += unilen, o += utflen) {
612
613 /* convert from nls to unicode */
614 unilen = nls->char2uni(&in[i], in_len - i, &uni);
615 if (unilen < 0)
616 goto conv_err;
617
618 /* convert from unicode to UTF-8 */
619 utflen = utf32_to_utf8(uni, &result[o], 3);
620 if (utflen <= 0)
621 goto conv_err;
622 }
623
624 result[o] = '\0';
625 *out_len = o;
626
627 befs_debug(sb, "<--- %s", __func__);
628
629 return i;
630
631conv_err:
632 befs_error(sb, "Name using character set %s contains a character that "
633 "cannot be converted to unicode.", nls->charset);
634 befs_debug(sb, "<--- %s", __func__);
635 kfree(result);
636 return -EILSEQ;
637}
638
639static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
640 uint32_t generation)
641{
642 /* No need to handle i_generation */
643 return befs_iget(sb, ino);
644}
645
646/*
647 * Map a NFS file handle to a corresponding dentry
648 */
649static struct dentry *befs_fh_to_dentry(struct super_block *sb,
650 struct fid *fid, int fh_len, int fh_type)
651{
652 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
653 befs_nfs_get_inode);
654}
655
656/*
657 * Find the parent for a file specified by NFS handle
658 */
659static struct dentry *befs_fh_to_parent(struct super_block *sb,
660 struct fid *fid, int fh_len, int fh_type)
661{
662 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
663 befs_nfs_get_inode);
664}
665
666static struct dentry *befs_get_parent(struct dentry *child)
667{
668 struct inode *parent;
669 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
670
671 parent = befs_iget(child->d_sb,
672 (unsigned long)befs_ino->i_parent.start);
673 if (IS_ERR(parent))
674 return ERR_CAST(parent);
675
676 return d_obtain_alias(parent);
677}
678
679enum {
680 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
681};
682
683static const match_table_t befs_tokens = {
684 {Opt_uid, "uid=%d"},
685 {Opt_gid, "gid=%d"},
686 {Opt_charset, "iocharset=%s"},
687 {Opt_debug, "debug"},
688 {Opt_err, NULL}
689};
690
691static int
692parse_options(char *options, struct befs_mount_options *opts)
693{
694 char *p;
695 substring_t args[MAX_OPT_ARGS];
696 int option;
697 kuid_t uid;
698 kgid_t gid;
699
700 /* Initialize options */
701 opts->uid = GLOBAL_ROOT_UID;
702 opts->gid = GLOBAL_ROOT_GID;
703 opts->use_uid = 0;
704 opts->use_gid = 0;
705 opts->iocharset = NULL;
706 opts->debug = 0;
707
708 if (!options)
709 return 1;
710
711 while ((p = strsep(&options, ",")) != NULL) {
712 int token;
713
714 if (!*p)
715 continue;
716
717 token = match_token(p, befs_tokens, args);
718 switch (token) {
719 case Opt_uid:
720 if (match_int(&args[0], &option))
721 return 0;
722 uid = INVALID_UID;
723 if (option >= 0)
724 uid = make_kuid(current_user_ns(), option);
725 if (!uid_valid(uid)) {
726 pr_err("Invalid uid %d, "
727 "using default\n", option);
728 break;
729 }
730 opts->uid = uid;
731 opts->use_uid = 1;
732 break;
733 case Opt_gid:
734 if (match_int(&args[0], &option))
735 return 0;
736 gid = INVALID_GID;
737 if (option >= 0)
738 gid = make_kgid(current_user_ns(), option);
739 if (!gid_valid(gid)) {
740 pr_err("Invalid gid %d, "
741 "using default\n", option);
742 break;
743 }
744 opts->gid = gid;
745 opts->use_gid = 1;
746 break;
747 case Opt_charset:
748 kfree(opts->iocharset);
749 opts->iocharset = match_strdup(&args[0]);
750 if (!opts->iocharset) {
751 pr_err("allocation failure for "
752 "iocharset string\n");
753 return 0;
754 }
755 break;
756 case Opt_debug:
757 opts->debug = 1;
758 break;
759 default:
760 pr_err("Unrecognized mount option \"%s\" "
761 "or missing value\n", p);
762 return 0;
763 }
764 }
765 return 1;
766}
767
768static int befs_show_options(struct seq_file *m, struct dentry *root)
769{
770 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
771 struct befs_mount_options *opts = &befs_sb->mount_opts;
772
773 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
774 seq_printf(m, ",uid=%u",
775 from_kuid_munged(&init_user_ns, opts->uid));
776 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
777 seq_printf(m, ",gid=%u",
778 from_kgid_munged(&init_user_ns, opts->gid));
779 if (opts->iocharset)
780 seq_printf(m, ",charset=%s", opts->iocharset);
781 if (opts->debug)
782 seq_puts(m, ",debug");
783 return 0;
784}
785
786/* This function has the responsibiltiy of getting the
787 * filesystem ready for unmounting.
788 * Basically, we free everything that we allocated in
789 * befs_read_inode
790 */
791static void
792befs_put_super(struct super_block *sb)
793{
794 kfree(BEFS_SB(sb)->mount_opts.iocharset);
795 BEFS_SB(sb)->mount_opts.iocharset = NULL;
796 unload_nls(BEFS_SB(sb)->nls);
797 kfree(sb->s_fs_info);
798 sb->s_fs_info = NULL;
799}
800
801/* Allocate private field of the superblock, fill it.
802 *
803 * Finish filling the public superblock fields
804 * Make the root directory
805 * Load a set of NLS translations if needed.
806 */
807static int
808befs_fill_super(struct super_block *sb, void *data, int silent)
809{
810 struct buffer_head *bh;
811 struct befs_sb_info *befs_sb;
812 befs_super_block *disk_sb;
813 struct inode *root;
814 long ret = -EINVAL;
815 const unsigned long sb_block = 0;
816 const off_t x86_sb_off = 512;
817 int blocksize;
818
819 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
820 if (sb->s_fs_info == NULL)
821 goto unacquire_none;
822
823 befs_sb = BEFS_SB(sb);
824
825 if (!parse_options((char *) data, &befs_sb->mount_opts)) {
826 if (!silent)
827 befs_error(sb, "cannot parse mount options");
828 goto unacquire_priv_sbp;
829 }
830
831 befs_debug(sb, "---> %s", __func__);
832
833 if (!sb_rdonly(sb)) {
834 befs_warning(sb,
835 "No write support. Marking filesystem read-only");
836 sb->s_flags |= SB_RDONLY;
837 }
838
839 /*
840 * Set dummy blocksize to read super block.
841 * Will be set to real fs blocksize later.
842 *
843 * Linux 2.4.10 and later refuse to read blocks smaller than
844 * the logical block size for the device. But we also need to read at
845 * least 1k to get the second 512 bytes of the volume.
846 */
847 blocksize = sb_min_blocksize(sb, 1024);
848 if (!blocksize) {
849 if (!silent)
850 befs_error(sb, "unable to set blocksize");
851 goto unacquire_priv_sbp;
852 }
853
854 bh = sb_bread(sb, sb_block);
855 if (!bh) {
856 if (!silent)
857 befs_error(sb, "unable to read superblock");
858 goto unacquire_priv_sbp;
859 }
860
861 /* account for offset of super block on x86 */
862 disk_sb = (befs_super_block *) bh->b_data;
863 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
864 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
865 befs_debug(sb, "Using PPC superblock location");
866 } else {
867 befs_debug(sb, "Using x86 superblock location");
868 disk_sb =
869 (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
870 }
871
872 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
873 (befs_check_sb(sb) != BEFS_OK))
874 goto unacquire_bh;
875
876 befs_dump_super_block(sb, disk_sb);
877
878 brelse(bh);
879
880 if (befs_sb->num_blocks > ~((sector_t)0)) {
881 if (!silent)
882 befs_error(sb, "blocks count: %llu is larger than the host can use",
883 befs_sb->num_blocks);
884 goto unacquire_priv_sbp;
885 }
886
887 /*
888 * set up enough so that it can read an inode
889 * Fill in kernel superblock fields from private sb
890 */
891 sb->s_magic = BEFS_SUPER_MAGIC;
892 /* Set real blocksize of fs */
893 sb_set_blocksize(sb, (ulong) befs_sb->block_size);
894 sb->s_op = &befs_sops;
895 sb->s_export_op = &befs_export_operations;
896 sb->s_time_min = 0;
897 sb->s_time_max = 0xffffffffffffll;
898 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
899 if (IS_ERR(root)) {
900 ret = PTR_ERR(root);
901 goto unacquire_priv_sbp;
902 }
903 sb->s_root = d_make_root(root);
904 if (!sb->s_root) {
905 if (!silent)
906 befs_error(sb, "get root inode failed");
907 goto unacquire_priv_sbp;
908 }
909
910 /* load nls library */
911 if (befs_sb->mount_opts.iocharset) {
912 befs_debug(sb, "Loading nls: %s",
913 befs_sb->mount_opts.iocharset);
914 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
915 if (!befs_sb->nls) {
916 befs_warning(sb, "Cannot load nls %s"
917 " loading default nls",
918 befs_sb->mount_opts.iocharset);
919 befs_sb->nls = load_nls_default();
920 }
921 /* load default nls if none is specified in mount options */
922 } else {
923 befs_debug(sb, "Loading default nls");
924 befs_sb->nls = load_nls_default();
925 }
926
927 return 0;
928
929unacquire_bh:
930 brelse(bh);
931
932unacquire_priv_sbp:
933 kfree(befs_sb->mount_opts.iocharset);
934 kfree(sb->s_fs_info);
935 sb->s_fs_info = NULL;
936
937unacquire_none:
938 return ret;
939}
940
941static int
942befs_remount(struct super_block *sb, int *flags, char *data)
943{
944 sync_filesystem(sb);
945 if (!(*flags & SB_RDONLY))
946 return -EINVAL;
947 return 0;
948}
949
950static int
951befs_statfs(struct dentry *dentry, struct kstatfs *buf)
952{
953 struct super_block *sb = dentry->d_sb;
954 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
955
956 befs_debug(sb, "---> %s", __func__);
957
958 buf->f_type = BEFS_SUPER_MAGIC;
959 buf->f_bsize = sb->s_blocksize;
960 buf->f_blocks = BEFS_SB(sb)->num_blocks;
961 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
962 buf->f_bavail = buf->f_bfree;
963 buf->f_files = 0; /* UNKNOWN */
964 buf->f_ffree = 0; /* UNKNOWN */
965 buf->f_fsid = u64_to_fsid(id);
966 buf->f_namelen = BEFS_NAME_LEN;
967
968 befs_debug(sb, "<--- %s", __func__);
969
970 return 0;
971}
972
973static struct dentry *
974befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
975 void *data)
976{
977 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
978}
979
980static struct file_system_type befs_fs_type = {
981 .owner = THIS_MODULE,
982 .name = "befs",
983 .mount = befs_mount,
984 .kill_sb = kill_block_super,
985 .fs_flags = FS_REQUIRES_DEV,
986};
987MODULE_ALIAS_FS("befs");
988
989static int __init
990init_befs_fs(void)
991{
992 int err;
993
994 pr_info("version: %s\n", BEFS_VERSION);
995
996 err = befs_init_inodecache();
997 if (err)
998 goto unacquire_none;
999
1000 err = register_filesystem(&befs_fs_type);
1001 if (err)
1002 goto unacquire_inodecache;
1003
1004 return 0;
1005
1006unacquire_inodecache:
1007 befs_destroy_inodecache();
1008
1009unacquire_none:
1010 return err;
1011}
1012
1013static void __exit
1014exit_befs_fs(void)
1015{
1016 befs_destroy_inodecache();
1017
1018 unregister_filesystem(&befs_fs_type);
1019}
1020
1021/*
1022 * Macros that typecheck the init and exit functions,
1023 * ensures that they are called at init and cleanup,
1024 * and eliminates warnings about unused functions.
1025 */
1026module_init(init_befs_fs)
1027module_exit(exit_befs_fs)