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1 /*
2  *  linux/fs/affs/inode.c
3  *
4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
5  *
6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
7  *
8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
9  *
10  *  (C) 1991  Linus Torvalds - minix filesystem
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/parser.h>
17 #include <linux/magic.h>
18 #include <linux/sched.h>
19 #include "affs.h"
20 
21 extern struct timezone sys_tz;
22 
23 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
24 static int affs_remount (struct super_block *sb, int *flags, char *data);
25 
26 static void
affs_put_super(struct super_block * sb)27 affs_put_super(struct super_block *sb)
28 {
29 	struct affs_sb_info *sbi = AFFS_SB(sb);
30 	pr_debug("AFFS: put_super()\n");
31 
32 	if (!(sb->s_flags & MS_RDONLY)) {
33 		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
34 		secs_to_datestamp(get_seconds(),
35 				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
36 		affs_fix_checksum(sb, sbi->s_root_bh);
37 		mark_buffer_dirty(sbi->s_root_bh);
38 	}
39 
40 	kfree(sbi->s_prefix);
41 	affs_free_bitmap(sb);
42 	affs_brelse(sbi->s_root_bh);
43 	kfree(sbi);
44 	sb->s_fs_info = NULL;
45 	return;
46 }
47 
48 static void
affs_write_super(struct super_block * sb)49 affs_write_super(struct super_block *sb)
50 {
51 	int clean = 2;
52 	struct affs_sb_info *sbi = AFFS_SB(sb);
53 
54 	if (!(sb->s_flags & MS_RDONLY)) {
55 		//	if (sbi->s_bitmap[i].bm_bh) {
56 		//		if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
57 		//			clean = 0;
58 		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
59 		secs_to_datestamp(get_seconds(),
60 				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
61 		affs_fix_checksum(sb, sbi->s_root_bh);
62 		mark_buffer_dirty(sbi->s_root_bh);
63 		sb->s_dirt = !clean;	/* redo until bitmap synced */
64 	} else
65 		sb->s_dirt = 0;
66 
67 	pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
68 }
69 
70 static struct kmem_cache * affs_inode_cachep;
71 
affs_alloc_inode(struct super_block * sb)72 static struct inode *affs_alloc_inode(struct super_block *sb)
73 {
74 	struct affs_inode_info *i;
75 
76 	i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
77 	if (!i)
78 		return NULL;
79 
80 	i->vfs_inode.i_version = 1;
81 	i->i_lc = NULL;
82 	i->i_ext_bh = NULL;
83 	i->i_pa_cnt = 0;
84 
85 	return &i->vfs_inode;
86 }
87 
affs_destroy_inode(struct inode * inode)88 static void affs_destroy_inode(struct inode *inode)
89 {
90 	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
91 }
92 
init_once(void * foo)93 static void init_once(void *foo)
94 {
95 	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
96 
97 	init_MUTEX(&ei->i_link_lock);
98 	init_MUTEX(&ei->i_ext_lock);
99 	inode_init_once(&ei->vfs_inode);
100 }
101 
init_inodecache(void)102 static int init_inodecache(void)
103 {
104 	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
105 					     sizeof(struct affs_inode_info),
106 					     0, (SLAB_RECLAIM_ACCOUNT|
107 						SLAB_MEM_SPREAD),
108 					     init_once);
109 	if (affs_inode_cachep == NULL)
110 		return -ENOMEM;
111 	return 0;
112 }
113 
destroy_inodecache(void)114 static void destroy_inodecache(void)
115 {
116 	kmem_cache_destroy(affs_inode_cachep);
117 }
118 
119 static const struct super_operations affs_sops = {
120 	.alloc_inode	= affs_alloc_inode,
121 	.destroy_inode	= affs_destroy_inode,
122 	.write_inode	= affs_write_inode,
123 	.delete_inode	= affs_delete_inode,
124 	.clear_inode	= affs_clear_inode,
125 	.put_super	= affs_put_super,
126 	.write_super	= affs_write_super,
127 	.statfs		= affs_statfs,
128 	.remount_fs	= affs_remount,
129 	.show_options	= generic_show_options,
130 };
131 
132 enum {
133 	Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
134 	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
135 	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
136 };
137 
138 static const match_table_t tokens = {
139 	{Opt_bs, "bs=%u"},
140 	{Opt_mode, "mode=%o"},
141 	{Opt_mufs, "mufs"},
142 	{Opt_prefix, "prefix=%s"},
143 	{Opt_protect, "protect"},
144 	{Opt_reserved, "reserved=%u"},
145 	{Opt_root, "root=%u"},
146 	{Opt_setgid, "setgid=%u"},
147 	{Opt_setuid, "setuid=%u"},
148 	{Opt_verbose, "verbose"},
149 	{Opt_volume, "volume=%s"},
150 	{Opt_ignore, "grpquota"},
151 	{Opt_ignore, "noquota"},
152 	{Opt_ignore, "quota"},
153 	{Opt_ignore, "usrquota"},
154 	{Opt_err, NULL},
155 };
156 
157 static int
parse_options(char * options,uid_t * uid,gid_t * gid,int * mode,int * reserved,s32 * root,int * blocksize,char ** prefix,char * volume,unsigned long * mount_opts)158 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
159 		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
160 {
161 	char *p;
162 	substring_t args[MAX_OPT_ARGS];
163 
164 	/* Fill in defaults */
165 
166 	*uid        = current_uid();
167 	*gid        = current_gid();
168 	*reserved   = 2;
169 	*root       = -1;
170 	*blocksize  = -1;
171 	volume[0]   = ':';
172 	volume[1]   = 0;
173 	*mount_opts = 0;
174 	if (!options)
175 		return 1;
176 
177 	while ((p = strsep(&options, ",")) != NULL) {
178 		int token, n, option;
179 		if (!*p)
180 			continue;
181 
182 		token = match_token(p, tokens, args);
183 		switch (token) {
184 		case Opt_bs:
185 			if (match_int(&args[0], &n))
186 				return -EINVAL;
187 			if (n != 512 && n != 1024 && n != 2048
188 			    && n != 4096) {
189 				printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
190 				return 0;
191 			}
192 			*blocksize = n;
193 			break;
194 		case Opt_mode:
195 			if (match_octal(&args[0], &option))
196 				return 1;
197 			*mode = option & 0777;
198 			*mount_opts |= SF_SETMODE;
199 			break;
200 		case Opt_mufs:
201 			*mount_opts |= SF_MUFS;
202 			break;
203 		case Opt_prefix:
204 			/* Free any previous prefix */
205 			kfree(*prefix);
206 			*prefix = match_strdup(&args[0]);
207 			if (!*prefix)
208 				return 0;
209 			*mount_opts |= SF_PREFIX;
210 			break;
211 		case Opt_protect:
212 			*mount_opts |= SF_IMMUTABLE;
213 			break;
214 		case Opt_reserved:
215 			if (match_int(&args[0], reserved))
216 				return 1;
217 			break;
218 		case Opt_root:
219 			if (match_int(&args[0], root))
220 				return 1;
221 			break;
222 		case Opt_setgid:
223 			if (match_int(&args[0], &option))
224 				return 1;
225 			*gid = option;
226 			*mount_opts |= SF_SETGID;
227 			break;
228 		case Opt_setuid:
229 			if (match_int(&args[0], &option))
230 				return -EINVAL;
231 			*uid = option;
232 			*mount_opts |= SF_SETUID;
233 			break;
234 		case Opt_verbose:
235 			*mount_opts |= SF_VERBOSE;
236 			break;
237 		case Opt_volume: {
238 			char *vol = match_strdup(&args[0]);
239 			if (!vol)
240 				return 0;
241 			strlcpy(volume, vol, 32);
242 			kfree(vol);
243 			break;
244 		}
245 		case Opt_ignore:
246 		 	/* Silently ignore the quota options */
247 			break;
248 		default:
249 			printk("AFFS: Unrecognized mount option \"%s\" "
250 					"or missing value\n", p);
251 			return 0;
252 		}
253 	}
254 	return 1;
255 }
256 
257 /* This function definitely needs to be split up. Some fine day I'll
258  * hopefully have the guts to do so. Until then: sorry for the mess.
259  */
260 
affs_fill_super(struct super_block * sb,void * data,int silent)261 static int affs_fill_super(struct super_block *sb, void *data, int silent)
262 {
263 	struct affs_sb_info	*sbi;
264 	struct buffer_head	*root_bh = NULL;
265 	struct buffer_head	*boot_bh;
266 	struct inode		*root_inode = NULL;
267 	s32			 root_block;
268 	int			 size, blocksize;
269 	u32			 chksum;
270 	int			 num_bm;
271 	int			 i, j;
272 	s32			 key;
273 	uid_t			 uid;
274 	gid_t			 gid;
275 	int			 reserved;
276 	unsigned long		 mount_flags;
277 	int			 tmp_flags;	/* fix remount prototype... */
278 	u8			 sig[4];
279 	int			 ret = -EINVAL;
280 
281 	save_mount_options(sb, data);
282 
283 	pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
284 
285 	sb->s_magic             = AFFS_SUPER_MAGIC;
286 	sb->s_op                = &affs_sops;
287 	sb->s_flags |= MS_NODIRATIME;
288 
289 	sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
290 	if (!sbi)
291 		return -ENOMEM;
292 	sb->s_fs_info = sbi;
293 	mutex_init(&sbi->s_bmlock);
294 
295 	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
296 				&blocksize,&sbi->s_prefix,
297 				sbi->s_volume, &mount_flags)) {
298 		printk(KERN_ERR "AFFS: Error parsing options\n");
299 		return -EINVAL;
300 	}
301 	/* N.B. after this point s_prefix must be released */
302 
303 	sbi->s_flags   = mount_flags;
304 	sbi->s_mode    = i;
305 	sbi->s_uid     = uid;
306 	sbi->s_gid     = gid;
307 	sbi->s_reserved= reserved;
308 
309 	/* Get the size of the device in 512-byte blocks.
310 	 * If we later see that the partition uses bigger
311 	 * blocks, we will have to change it.
312 	 */
313 
314 	size = sb->s_bdev->bd_inode->i_size >> 9;
315 	pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
316 
317 	affs_set_blocksize(sb, PAGE_SIZE);
318 	/* Try to find root block. Its location depends on the block size. */
319 
320 	i = 512;
321 	j = 4096;
322 	if (blocksize > 0) {
323 		i = j = blocksize;
324 		size = size / (blocksize / 512);
325 	}
326 	for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
327 		sbi->s_root_block = root_block;
328 		if (root_block < 0)
329 			sbi->s_root_block = (reserved + size - 1) / 2;
330 		pr_debug("AFFS: setting blocksize to %d\n", blocksize);
331 		affs_set_blocksize(sb, blocksize);
332 		sbi->s_partition_size = size;
333 
334 		/* The root block location that was calculated above is not
335 		 * correct if the partition size is an odd number of 512-
336 		 * byte blocks, which will be rounded down to a number of
337 		 * 1024-byte blocks, and if there were an even number of
338 		 * reserved blocks. Ideally, all partition checkers should
339 		 * report the real number of blocks of the real blocksize,
340 		 * but since this just cannot be done, we have to try to
341 		 * find the root block anyways. In the above case, it is one
342 		 * block behind the calculated one. So we check this one, too.
343 		 */
344 		for (num_bm = 0; num_bm < 2; num_bm++) {
345 			pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
346 				"size=%d, reserved=%d\n",
347 				sb->s_id,
348 				sbi->s_root_block + num_bm,
349 				blocksize, size, reserved);
350 			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
351 			if (!root_bh)
352 				continue;
353 			if (!affs_checksum_block(sb, root_bh) &&
354 			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
355 			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
356 				sbi->s_hashsize    = blocksize / 4 - 56;
357 				sbi->s_root_block += num_bm;
358 				key                        = 1;
359 				goto got_root;
360 			}
361 			affs_brelse(root_bh);
362 			root_bh = NULL;
363 		}
364 	}
365 	if (!silent)
366 		printk(KERN_ERR "AFFS: No valid root block on device %s\n",
367 			sb->s_id);
368 	goto out_error;
369 
370 	/* N.B. after this point bh must be released */
371 got_root:
372 	root_block = sbi->s_root_block;
373 
374 	/* Find out which kind of FS we have */
375 	boot_bh = sb_bread(sb, 0);
376 	if (!boot_bh) {
377 		printk(KERN_ERR "AFFS: Cannot read boot block\n");
378 		goto out_error;
379 	}
380 	memcpy(sig, boot_bh->b_data, 4);
381 	brelse(boot_bh);
382 	chksum = be32_to_cpu(*(__be32 *)sig);
383 
384 	/* Dircache filesystems are compatible with non-dircache ones
385 	 * when reading. As long as they aren't supported, writing is
386 	 * not recommended.
387 	 */
388 	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
389 	     || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
390 		printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
391 			sb->s_id);
392 		sb->s_flags |= MS_RDONLY;
393 	}
394 	switch (chksum) {
395 		case MUFS_FS:
396 		case MUFS_INTLFFS:
397 		case MUFS_DCFFS:
398 			sbi->s_flags |= SF_MUFS;
399 			/* fall thru */
400 		case FS_INTLFFS:
401 		case FS_DCFFS:
402 			sbi->s_flags |= SF_INTL;
403 			break;
404 		case MUFS_FFS:
405 			sbi->s_flags |= SF_MUFS;
406 			break;
407 		case FS_FFS:
408 			break;
409 		case MUFS_OFS:
410 			sbi->s_flags |= SF_MUFS;
411 			/* fall thru */
412 		case FS_OFS:
413 			sbi->s_flags |= SF_OFS;
414 			sb->s_flags |= MS_NOEXEC;
415 			break;
416 		case MUFS_DCOFS:
417 		case MUFS_INTLOFS:
418 			sbi->s_flags |= SF_MUFS;
419 		case FS_DCOFS:
420 		case FS_INTLOFS:
421 			sbi->s_flags |= SF_INTL | SF_OFS;
422 			sb->s_flags |= MS_NOEXEC;
423 			break;
424 		default:
425 			printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
426 				sb->s_id, chksum);
427 			goto out_error;
428 	}
429 
430 	if (mount_flags & SF_VERBOSE) {
431 		u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
432 		printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
433 			len > 31 ? 31 : len,
434 			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
435 			sig, sig[3] + '0', blocksize);
436 	}
437 
438 	sb->s_flags |= MS_NODEV | MS_NOSUID;
439 
440 	sbi->s_data_blksize = sb->s_blocksize;
441 	if (sbi->s_flags & SF_OFS)
442 		sbi->s_data_blksize -= 24;
443 
444 	/* Keep super block in cache */
445 	sbi->s_root_bh = root_bh;
446 	/* N.B. after this point s_root_bh must be released */
447 
448 	tmp_flags = sb->s_flags;
449 	if (affs_init_bitmap(sb, &tmp_flags))
450 		goto out_error;
451 	sb->s_flags = tmp_flags;
452 
453 	/* set up enough so that it can read an inode */
454 
455 	root_inode = affs_iget(sb, root_block);
456 	if (IS_ERR(root_inode)) {
457 		ret = PTR_ERR(root_inode);
458 		goto out_error_noinode;
459 	}
460 
461 	sb->s_root = d_alloc_root(root_inode);
462 	if (!sb->s_root) {
463 		printk(KERN_ERR "AFFS: Get root inode failed\n");
464 		goto out_error;
465 	}
466 	sb->s_root->d_op = &affs_dentry_operations;
467 
468 	pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
469 	return 0;
470 
471 	/*
472 	 * Begin the cascaded cleanup ...
473 	 */
474 out_error:
475 	if (root_inode)
476 		iput(root_inode);
477 out_error_noinode:
478 	kfree(sbi->s_bitmap);
479 	affs_brelse(root_bh);
480 	kfree(sbi->s_prefix);
481 	kfree(sbi);
482 	sb->s_fs_info = NULL;
483 	return ret;
484 }
485 
486 static int
affs_remount(struct super_block * sb,int * flags,char * data)487 affs_remount(struct super_block *sb, int *flags, char *data)
488 {
489 	struct affs_sb_info	*sbi = AFFS_SB(sb);
490 	int			 blocksize;
491 	uid_t			 uid;
492 	gid_t			 gid;
493 	int			 mode;
494 	int			 reserved;
495 	int			 root_block;
496 	unsigned long		 mount_flags;
497 	int			 res = 0;
498 	char			*new_opts = kstrdup(data, GFP_KERNEL);
499 
500 	pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
501 
502 	*flags |= MS_NODIRATIME;
503 
504 	if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
505 			   &blocksize, &sbi->s_prefix, sbi->s_volume,
506 			   &mount_flags)) {
507 		kfree(new_opts);
508 		return -EINVAL;
509 	}
510 	kfree(sb->s_options);
511 	sb->s_options = new_opts;
512 
513 	sbi->s_flags = mount_flags;
514 	sbi->s_mode  = mode;
515 	sbi->s_uid   = uid;
516 	sbi->s_gid   = gid;
517 
518 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
519 		return 0;
520 	if (*flags & MS_RDONLY) {
521 		sb->s_dirt = 1;
522 		while (sb->s_dirt)
523 			affs_write_super(sb);
524 		affs_free_bitmap(sb);
525 	} else
526 		res = affs_init_bitmap(sb, flags);
527 
528 	return res;
529 }
530 
531 static int
affs_statfs(struct dentry * dentry,struct kstatfs * buf)532 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
533 {
534 	struct super_block *sb = dentry->d_sb;
535 	int		 free;
536 
537 	pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
538 	     AFFS_SB(sb)->s_reserved);
539 
540 	free          = affs_count_free_blocks(sb);
541 	buf->f_type    = AFFS_SUPER_MAGIC;
542 	buf->f_bsize   = sb->s_blocksize;
543 	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
544 	buf->f_bfree   = free;
545 	buf->f_bavail  = free;
546 	return 0;
547 }
548 
affs_get_sb(struct file_system_type * fs_type,int flags,const char * dev_name,void * data,struct vfsmount * mnt)549 static int affs_get_sb(struct file_system_type *fs_type,
550 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
551 {
552 	return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
553 			   mnt);
554 }
555 
556 static struct file_system_type affs_fs_type = {
557 	.owner		= THIS_MODULE,
558 	.name		= "affs",
559 	.get_sb		= affs_get_sb,
560 	.kill_sb	= kill_block_super,
561 	.fs_flags	= FS_REQUIRES_DEV,
562 };
563 
init_affs_fs(void)564 static int __init init_affs_fs(void)
565 {
566 	int err = init_inodecache();
567 	if (err)
568 		goto out1;
569 	err = register_filesystem(&affs_fs_type);
570 	if (err)
571 		goto out;
572 	return 0;
573 out:
574 	destroy_inodecache();
575 out1:
576 	return err;
577 }
578 
exit_affs_fs(void)579 static void __exit exit_affs_fs(void)
580 {
581 	unregister_filesystem(&affs_fs_type);
582 	destroy_inodecache();
583 }
584 
585 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
586 MODULE_LICENSE("GPL");
587 
588 module_init(init_affs_fs)
589 module_exit(exit_affs_fs)
590