xref: /openbmc/linux/fs/affs/super.c (revision 87c2ce3b)
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 "affs.h"
18 
19 extern struct timezone sys_tz;
20 
21 static int affs_statfs(struct super_block *sb, struct kstatfs *buf);
22 static int affs_remount (struct super_block *sb, int *flags, char *data);
23 
24 static void
25 affs_put_super(struct super_block *sb)
26 {
27 	struct affs_sb_info *sbi = AFFS_SB(sb);
28 	pr_debug("AFFS: put_super()\n");
29 
30 	if (!(sb->s_flags & MS_RDONLY)) {
31 		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
32 		secs_to_datestamp(get_seconds(),
33 				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
34 		affs_fix_checksum(sb, sbi->s_root_bh);
35 		mark_buffer_dirty(sbi->s_root_bh);
36 	}
37 
38 	kfree(sbi->s_prefix);
39 	affs_free_bitmap(sb);
40 	affs_brelse(sbi->s_root_bh);
41 	kfree(sbi);
42 	sb->s_fs_info = NULL;
43 	return;
44 }
45 
46 static void
47 affs_write_super(struct super_block *sb)
48 {
49 	int clean = 2;
50 	struct affs_sb_info *sbi = AFFS_SB(sb);
51 
52 	if (!(sb->s_flags & MS_RDONLY)) {
53 		//	if (sbi->s_bitmap[i].bm_bh) {
54 		//		if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
55 		//			clean = 0;
56 		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
57 		secs_to_datestamp(get_seconds(),
58 				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
59 		affs_fix_checksum(sb, sbi->s_root_bh);
60 		mark_buffer_dirty(sbi->s_root_bh);
61 		sb->s_dirt = !clean;	/* redo until bitmap synced */
62 	} else
63 		sb->s_dirt = 0;
64 
65 	pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
66 }
67 
68 static kmem_cache_t * affs_inode_cachep;
69 
70 static struct inode *affs_alloc_inode(struct super_block *sb)
71 {
72 	struct affs_inode_info *ei;
73 	ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, SLAB_KERNEL);
74 	if (!ei)
75 		return NULL;
76 	ei->vfs_inode.i_version = 1;
77 	return &ei->vfs_inode;
78 }
79 
80 static void affs_destroy_inode(struct inode *inode)
81 {
82 	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
83 }
84 
85 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
86 {
87 	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
88 
89 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
90 	    SLAB_CTOR_CONSTRUCTOR) {
91 		init_MUTEX(&ei->i_link_lock);
92 		init_MUTEX(&ei->i_ext_lock);
93 		inode_init_once(&ei->vfs_inode);
94 	}
95 }
96 
97 static int init_inodecache(void)
98 {
99 	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
100 					     sizeof(struct affs_inode_info),
101 					     0, SLAB_RECLAIM_ACCOUNT,
102 					     init_once, NULL);
103 	if (affs_inode_cachep == NULL)
104 		return -ENOMEM;
105 	return 0;
106 }
107 
108 static void destroy_inodecache(void)
109 {
110 	if (kmem_cache_destroy(affs_inode_cachep))
111 		printk(KERN_INFO "affs_inode_cache: not all structures were freed\n");
112 }
113 
114 static struct super_operations affs_sops = {
115 	.alloc_inode	= affs_alloc_inode,
116 	.destroy_inode	= affs_destroy_inode,
117 	.read_inode	= affs_read_inode,
118 	.write_inode	= affs_write_inode,
119 	.put_inode	= affs_put_inode,
120 	.delete_inode	= affs_delete_inode,
121 	.clear_inode	= affs_clear_inode,
122 	.put_super	= affs_put_super,
123 	.write_super	= affs_write_super,
124 	.statfs		= affs_statfs,
125 	.remount_fs	= affs_remount,
126 };
127 
128 enum {
129 	Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
130 	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
131 	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
132 };
133 
134 static match_table_t tokens = {
135 	{Opt_bs, "bs=%u"},
136 	{Opt_mode, "mode=%o"},
137 	{Opt_mufs, "mufs"},
138 	{Opt_prefix, "prefix=%s"},
139 	{Opt_protect, "protect"},
140 	{Opt_reserved, "reserved=%u"},
141 	{Opt_root, "root=%u"},
142 	{Opt_setgid, "setgid=%u"},
143 	{Opt_setuid, "setuid=%u"},
144 	{Opt_verbose, "verbose"},
145 	{Opt_volume, "volume=%s"},
146 	{Opt_ignore, "grpquota"},
147 	{Opt_ignore, "noquota"},
148 	{Opt_ignore, "quota"},
149 	{Opt_ignore, "usrquota"},
150 	{Opt_err, NULL},
151 };
152 
153 static int
154 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
155 		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
156 {
157 	char *p;
158 	substring_t args[MAX_OPT_ARGS];
159 
160 	/* Fill in defaults */
161 
162 	*uid        = current->uid;
163 	*gid        = current->gid;
164 	*reserved   = 2;
165 	*root       = -1;
166 	*blocksize  = -1;
167 	volume[0]   = ':';
168 	volume[1]   = 0;
169 	*mount_opts = 0;
170 	if (!options)
171 		return 1;
172 
173 	while ((p = strsep(&options, ",")) != NULL) {
174 		int token, n, option;
175 		if (!*p)
176 			continue;
177 
178 		token = match_token(p, tokens, args);
179 		switch (token) {
180 		case Opt_bs:
181 			if (match_int(&args[0], &n))
182 				return -EINVAL;
183 			if (n != 512 && n != 1024 && n != 2048
184 			    && n != 4096) {
185 				printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
186 				return 0;
187 			}
188 			*blocksize = n;
189 			break;
190 		case Opt_mode:
191 			if (match_octal(&args[0], &option))
192 				return 1;
193 			*mode = option & 0777;
194 			*mount_opts |= SF_SETMODE;
195 			break;
196 		case Opt_mufs:
197 			*mount_opts |= SF_MUFS;
198 			break;
199 		case Opt_prefix:
200 			/* Free any previous prefix */
201 			kfree(*prefix);
202 			*prefix = NULL;
203 			*prefix = match_strdup(&args[0]);
204 			if (!*prefix)
205 				return 0;
206 			*mount_opts |= SF_PREFIX;
207 			break;
208 		case Opt_protect:
209 			*mount_opts |= SF_IMMUTABLE;
210 			break;
211 		case Opt_reserved:
212 			if (match_int(&args[0], reserved))
213 				return 1;
214 			break;
215 		case Opt_root:
216 			if (match_int(&args[0], root))
217 				return 1;
218 			break;
219 		case Opt_setgid:
220 			if (match_int(&args[0], &option))
221 				return 1;
222 			*gid = option;
223 			*mount_opts |= SF_SETGID;
224 			break;
225 		case Opt_setuid:
226 			if (match_int(&args[0], &option))
227 				return -EINVAL;
228 			*uid = option;
229 			*mount_opts |= SF_SETUID;
230 			break;
231 		case Opt_verbose:
232 			*mount_opts |= SF_VERBOSE;
233 			break;
234 		case Opt_volume: {
235 			char *vol = match_strdup(&args[0]);
236 			strlcpy(volume, vol, 32);
237 			kfree(vol);
238 			break;
239 		}
240 		case Opt_ignore:
241 		 	/* Silently ignore the quota options */
242 			break;
243 		default:
244 			printk("AFFS: Unrecognized mount option \"%s\" "
245 					"or missing value\n", p);
246 			return 0;
247 		}
248 	}
249 	return 1;
250 }
251 
252 /* This function definitely needs to be split up. Some fine day I'll
253  * hopefully have the guts to do so. Until then: sorry for the mess.
254  */
255 
256 static int affs_fill_super(struct super_block *sb, void *data, int silent)
257 {
258 	struct affs_sb_info	*sbi;
259 	struct buffer_head	*root_bh = NULL;
260 	struct buffer_head	*boot_bh;
261 	struct inode		*root_inode = NULL;
262 	s32			 root_block;
263 	int			 size, blocksize;
264 	u32			 chksum;
265 	int			 num_bm;
266 	int			 i, j;
267 	s32			 key;
268 	uid_t			 uid;
269 	gid_t			 gid;
270 	int			 reserved;
271 	unsigned long		 mount_flags;
272 	int			 tmp_flags;	/* fix remount prototype... */
273 
274 	pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
275 
276 	sb->s_magic             = AFFS_SUPER_MAGIC;
277 	sb->s_op                = &affs_sops;
278 	sb->s_flags |= MS_NODIRATIME;
279 
280 	sbi = kmalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
281 	if (!sbi)
282 		return -ENOMEM;
283 	sb->s_fs_info = sbi;
284 	memset(sbi, 0, sizeof(*sbi));
285 	init_MUTEX(&sbi->s_bmlock);
286 
287 	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
288 				&blocksize,&sbi->s_prefix,
289 				sbi->s_volume, &mount_flags)) {
290 		printk(KERN_ERR "AFFS: Error parsing options\n");
291 		return -EINVAL;
292 	}
293 	/* N.B. after this point s_prefix must be released */
294 
295 	sbi->s_flags   = mount_flags;
296 	sbi->s_mode    = i;
297 	sbi->s_uid     = uid;
298 	sbi->s_gid     = gid;
299 	sbi->s_reserved= reserved;
300 
301 	/* Get the size of the device in 512-byte blocks.
302 	 * If we later see that the partition uses bigger
303 	 * blocks, we will have to change it.
304 	 */
305 
306 	size = sb->s_bdev->bd_inode->i_size >> 9;
307 	pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
308 
309 	affs_set_blocksize(sb, PAGE_SIZE);
310 	/* Try to find root block. Its location depends on the block size. */
311 
312 	i = 512;
313 	j = 4096;
314 	if (blocksize > 0) {
315 		i = j = blocksize;
316 		size = size / (blocksize / 512);
317 	}
318 	for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
319 		sbi->s_root_block = root_block;
320 		if (root_block < 0)
321 			sbi->s_root_block = (reserved + size - 1) / 2;
322 		pr_debug("AFFS: setting blocksize to %d\n", blocksize);
323 		affs_set_blocksize(sb, blocksize);
324 		sbi->s_partition_size = size;
325 
326 		/* The root block location that was calculated above is not
327 		 * correct if the partition size is an odd number of 512-
328 		 * byte blocks, which will be rounded down to a number of
329 		 * 1024-byte blocks, and if there were an even number of
330 		 * reserved blocks. Ideally, all partition checkers should
331 		 * report the real number of blocks of the real blocksize,
332 		 * but since this just cannot be done, we have to try to
333 		 * find the root block anyways. In the above case, it is one
334 		 * block behind the calculated one. So we check this one, too.
335 		 */
336 		for (num_bm = 0; num_bm < 2; num_bm++) {
337 			pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
338 				"size=%d, reserved=%d\n",
339 				sb->s_id,
340 				sbi->s_root_block + num_bm,
341 				blocksize, size, reserved);
342 			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
343 			if (!root_bh)
344 				continue;
345 			if (!affs_checksum_block(sb, root_bh) &&
346 			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
347 			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
348 				sbi->s_hashsize    = blocksize / 4 - 56;
349 				sbi->s_root_block += num_bm;
350 				key                        = 1;
351 				goto got_root;
352 			}
353 			affs_brelse(root_bh);
354 			root_bh = NULL;
355 		}
356 	}
357 	if (!silent)
358 		printk(KERN_ERR "AFFS: No valid root block on device %s\n",
359 			sb->s_id);
360 	goto out_error;
361 
362 	/* N.B. after this point bh must be released */
363 got_root:
364 	root_block = sbi->s_root_block;
365 
366 	/* Find out which kind of FS we have */
367 	boot_bh = sb_bread(sb, 0);
368 	if (!boot_bh) {
369 		printk(KERN_ERR "AFFS: Cannot read boot block\n");
370 		goto out_error;
371 	}
372 	chksum = be32_to_cpu(*(__be32 *)boot_bh->b_data);
373 	brelse(boot_bh);
374 
375 	/* Dircache filesystems are compatible with non-dircache ones
376 	 * when reading. As long as they aren't supported, writing is
377 	 * not recommended.
378 	 */
379 	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
380 	     || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
381 		printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
382 			sb->s_id);
383 		sb->s_flags |= MS_RDONLY;
384 	}
385 	switch (chksum) {
386 		case MUFS_FS:
387 		case MUFS_INTLFFS:
388 		case MUFS_DCFFS:
389 			sbi->s_flags |= SF_MUFS;
390 			/* fall thru */
391 		case FS_INTLFFS:
392 		case FS_DCFFS:
393 			sbi->s_flags |= SF_INTL;
394 			break;
395 		case MUFS_FFS:
396 			sbi->s_flags |= SF_MUFS;
397 			break;
398 		case FS_FFS:
399 			break;
400 		case MUFS_OFS:
401 			sbi->s_flags |= SF_MUFS;
402 			/* fall thru */
403 		case FS_OFS:
404 			sbi->s_flags |= SF_OFS;
405 			sb->s_flags |= MS_NOEXEC;
406 			break;
407 		case MUFS_DCOFS:
408 		case MUFS_INTLOFS:
409 			sbi->s_flags |= SF_MUFS;
410 		case FS_DCOFS:
411 		case FS_INTLOFS:
412 			sbi->s_flags |= SF_INTL | SF_OFS;
413 			sb->s_flags |= MS_NOEXEC;
414 			break;
415 		default:
416 			printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
417 				sb->s_id, chksum);
418 			goto out_error;
419 	}
420 
421 	if (mount_flags & SF_VERBOSE) {
422 		chksum = cpu_to_be32(chksum);
423 		printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
424 			AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0],
425 			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
426 			(char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
427 	}
428 
429 	sb->s_flags |= MS_NODEV | MS_NOSUID;
430 
431 	sbi->s_data_blksize = sb->s_blocksize;
432 	if (sbi->s_flags & SF_OFS)
433 		sbi->s_data_blksize -= 24;
434 
435 	/* Keep super block in cache */
436 	sbi->s_root_bh = root_bh;
437 	/* N.B. after this point s_root_bh must be released */
438 
439 	tmp_flags = sb->s_flags;
440 	if (affs_init_bitmap(sb, &tmp_flags))
441 		goto out_error;
442 	sb->s_flags = tmp_flags;
443 
444 	/* set up enough so that it can read an inode */
445 
446 	root_inode = iget(sb, root_block);
447 	sb->s_root = d_alloc_root(root_inode);
448 	if (!sb->s_root) {
449 		printk(KERN_ERR "AFFS: Get root inode failed\n");
450 		goto out_error;
451 	}
452 	sb->s_root->d_op = &affs_dentry_operations;
453 
454 	pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
455 	return 0;
456 
457 	/*
458 	 * Begin the cascaded cleanup ...
459 	 */
460 out_error:
461 	if (root_inode)
462 		iput(root_inode);
463 	kfree(sbi->s_bitmap);
464 	affs_brelse(root_bh);
465 	kfree(sbi->s_prefix);
466 	kfree(sbi);
467 	sb->s_fs_info = NULL;
468 	return -EINVAL;
469 }
470 
471 static int
472 affs_remount(struct super_block *sb, int *flags, char *data)
473 {
474 	struct affs_sb_info	*sbi = AFFS_SB(sb);
475 	int			 blocksize;
476 	uid_t			 uid;
477 	gid_t			 gid;
478 	int			 mode;
479 	int			 reserved;
480 	int			 root_block;
481 	unsigned long		 mount_flags;
482 	int			 res = 0;
483 
484 	pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
485 
486 	*flags |= MS_NODIRATIME;
487 
488 	if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
489 	    &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
490 		return -EINVAL;
491 	sbi->s_flags = mount_flags;
492 	sbi->s_mode  = mode;
493 	sbi->s_uid   = uid;
494 	sbi->s_gid   = gid;
495 
496 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
497 		return 0;
498 	if (*flags & MS_RDONLY) {
499 		sb->s_dirt = 1;
500 		while (sb->s_dirt)
501 			affs_write_super(sb);
502 		affs_free_bitmap(sb);
503 	} else
504 		res = affs_init_bitmap(sb, flags);
505 
506 	return res;
507 }
508 
509 static int
510 affs_statfs(struct super_block *sb, struct kstatfs *buf)
511 {
512 	int		 free;
513 
514 	pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
515 	     AFFS_SB(sb)->s_reserved);
516 
517 	free          = affs_count_free_blocks(sb);
518 	buf->f_type    = AFFS_SUPER_MAGIC;
519 	buf->f_bsize   = sb->s_blocksize;
520 	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
521 	buf->f_bfree   = free;
522 	buf->f_bavail  = free;
523 	return 0;
524 }
525 
526 static struct super_block *affs_get_sb(struct file_system_type *fs_type,
527 	int flags, const char *dev_name, void *data)
528 {
529 	return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super);
530 }
531 
532 static struct file_system_type affs_fs_type = {
533 	.owner		= THIS_MODULE,
534 	.name		= "affs",
535 	.get_sb		= affs_get_sb,
536 	.kill_sb	= kill_block_super,
537 	.fs_flags	= FS_REQUIRES_DEV,
538 };
539 
540 static int __init init_affs_fs(void)
541 {
542 	int err = init_inodecache();
543 	if (err)
544 		goto out1;
545 	err = register_filesystem(&affs_fs_type);
546 	if (err)
547 		goto out;
548 	return 0;
549 out:
550 	destroy_inodecache();
551 out1:
552 	return err;
553 }
554 
555 static void __exit exit_affs_fs(void)
556 {
557 	unregister_filesystem(&affs_fs_type);
558 	destroy_inodecache();
559 }
560 
561 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
562 MODULE_LICENSE("GPL");
563 
564 module_init(init_affs_fs)
565 module_exit(exit_affs_fs)
566