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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/sysv/inode.c
4  *
5  *  minix/inode.c
6  *  Copyright (C) 1991, 1992  Linus Torvalds
7  *
8  *  xenix/inode.c
9  *  Copyright (C) 1992  Doug Evans
10  *
11  *  coh/inode.c
12  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
13  *
14  *  sysv/inode.c
15  *  Copyright (C) 1993  Paul B. Monday
16  *
17  *  sysv/inode.c
18  *  Copyright (C) 1993  Bruno Haible
19  *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
20  *
21  *  This file contains code for read/parsing the superblock.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/buffer_head.h>
28 #include "sysv.h"
29 
30 /*
31  * The following functions try to recognize specific filesystems.
32  *
33  * We recognize:
34  * - Xenix FS by its magic number.
35  * - SystemV FS by its magic number.
36  * - Coherent FS by its funny fname/fpack field.
37  * - SCO AFS by s_nfree == 0xffff
38  * - V7 FS has no distinguishing features.
39  *
40  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
41  * the time stamp is not < 01-01-1980.
42  */
43 
44 enum {
45 	JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60
46 };
47 
detected_xenix(struct sysv_sb_info * sbi,unsigned * max_links)48 static void detected_xenix(struct sysv_sb_info *sbi, unsigned *max_links)
49 {
50 	struct buffer_head *bh1 = sbi->s_bh1;
51 	struct buffer_head *bh2 = sbi->s_bh2;
52 	struct xenix_super_block * sbd1;
53 	struct xenix_super_block * sbd2;
54 
55 	if (bh1 != bh2)
56 		sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
57 	else {
58 		/* block size = 512, so bh1 != bh2 */
59 		sbd1 = (struct xenix_super_block *) bh1->b_data;
60 		sbd2 = (struct xenix_super_block *) (bh2->b_data - 512);
61 	}
62 
63 	*max_links = XENIX_LINK_MAX;
64 	sbi->s_fic_size = XENIX_NICINOD;
65 	sbi->s_flc_size = XENIX_NICFREE;
66 	sbi->s_sbd1 = (char *)sbd1;
67 	sbi->s_sbd2 = (char *)sbd2;
68 	sbi->s_sb_fic_count = &sbd1->s_ninode;
69 	sbi->s_sb_fic_inodes = &sbd1->s_inode[0];
70 	sbi->s_sb_total_free_inodes = &sbd2->s_tinode;
71 	sbi->s_bcache_count = &sbd1->s_nfree;
72 	sbi->s_bcache = &sbd1->s_free[0];
73 	sbi->s_free_blocks = &sbd2->s_tfree;
74 	sbi->s_sb_time = &sbd2->s_time;
75 	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd1->s_isize);
76 	sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize);
77 }
78 
detected_sysv4(struct sysv_sb_info * sbi,unsigned * max_links)79 static void detected_sysv4(struct sysv_sb_info *sbi, unsigned *max_links)
80 {
81 	struct sysv4_super_block * sbd;
82 	struct buffer_head *bh1 = sbi->s_bh1;
83 	struct buffer_head *bh2 = sbi->s_bh2;
84 
85 	if (bh1 == bh2)
86 		sbd = (struct sysv4_super_block *) (bh1->b_data + BLOCK_SIZE/2);
87 	else
88 		sbd = (struct sysv4_super_block *) bh2->b_data;
89 
90 	*max_links = SYSV_LINK_MAX;
91 	sbi->s_fic_size = SYSV_NICINOD;
92 	sbi->s_flc_size = SYSV_NICFREE;
93 	sbi->s_sbd1 = (char *)sbd;
94 	sbi->s_sbd2 = (char *)sbd;
95 	sbi->s_sb_fic_count = &sbd->s_ninode;
96 	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
97 	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
98 	sbi->s_bcache_count = &sbd->s_nfree;
99 	sbi->s_bcache = &sbd->s_free[0];
100 	sbi->s_free_blocks = &sbd->s_tfree;
101 	sbi->s_sb_time = &sbd->s_time;
102 	sbi->s_sb_state = &sbd->s_state;
103 	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
104 	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
105 }
106 
detected_sysv2(struct sysv_sb_info * sbi,unsigned * max_links)107 static void detected_sysv2(struct sysv_sb_info *sbi, unsigned *max_links)
108 {
109 	struct sysv2_super_block *sbd;
110 	struct buffer_head *bh1 = sbi->s_bh1;
111 	struct buffer_head *bh2 = sbi->s_bh2;
112 
113 	if (bh1 == bh2)
114 		sbd = (struct sysv2_super_block *) (bh1->b_data + BLOCK_SIZE/2);
115 	else
116 		sbd = (struct sysv2_super_block *) bh2->b_data;
117 
118 	*max_links = SYSV_LINK_MAX;
119 	sbi->s_fic_size = SYSV_NICINOD;
120 	sbi->s_flc_size = SYSV_NICFREE;
121 	sbi->s_sbd1 = (char *)sbd;
122 	sbi->s_sbd2 = (char *)sbd;
123 	sbi->s_sb_fic_count = &sbd->s_ninode;
124 	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
125 	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
126 	sbi->s_bcache_count = &sbd->s_nfree;
127 	sbi->s_bcache = &sbd->s_free[0];
128 	sbi->s_free_blocks = &sbd->s_tfree;
129 	sbi->s_sb_time = &sbd->s_time;
130 	sbi->s_sb_state = &sbd->s_state;
131 	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
132 	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
133 }
134 
detected_coherent(struct sysv_sb_info * sbi,unsigned * max_links)135 static void detected_coherent(struct sysv_sb_info *sbi, unsigned *max_links)
136 {
137 	struct coh_super_block * sbd;
138 	struct buffer_head *bh1 = sbi->s_bh1;
139 
140 	sbd = (struct coh_super_block *) bh1->b_data;
141 
142 	*max_links = COH_LINK_MAX;
143 	sbi->s_fic_size = COH_NICINOD;
144 	sbi->s_flc_size = COH_NICFREE;
145 	sbi->s_sbd1 = (char *)sbd;
146 	sbi->s_sbd2 = (char *)sbd;
147 	sbi->s_sb_fic_count = &sbd->s_ninode;
148 	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
149 	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
150 	sbi->s_bcache_count = &sbd->s_nfree;
151 	sbi->s_bcache = &sbd->s_free[0];
152 	sbi->s_free_blocks = &sbd->s_tfree;
153 	sbi->s_sb_time = &sbd->s_time;
154 	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
155 	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
156 }
157 
detected_v7(struct sysv_sb_info * sbi,unsigned * max_links)158 static void detected_v7(struct sysv_sb_info *sbi, unsigned *max_links)
159 {
160 	struct buffer_head *bh2 = sbi->s_bh2;
161 	struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data;
162 
163 	*max_links = V7_LINK_MAX;
164 	sbi->s_fic_size = V7_NICINOD;
165 	sbi->s_flc_size = V7_NICFREE;
166 	sbi->s_sbd1 = (char *)sbd;
167 	sbi->s_sbd2 = (char *)sbd;
168 	sbi->s_sb_fic_count = &sbd->s_ninode;
169 	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
170 	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
171 	sbi->s_bcache_count = &sbd->s_nfree;
172 	sbi->s_bcache = &sbd->s_free[0];
173 	sbi->s_free_blocks = &sbd->s_tfree;
174 	sbi->s_sb_time = &sbd->s_time;
175 	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
176 	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
177 }
178 
detect_xenix(struct sysv_sb_info * sbi,struct buffer_head * bh)179 static int detect_xenix(struct sysv_sb_info *sbi, struct buffer_head *bh)
180 {
181 	struct xenix_super_block *sbd = (struct xenix_super_block *)bh->b_data;
182 	if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0x2b5544))
183 		sbi->s_bytesex = BYTESEX_LE;
184 	else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0x2b5544))
185 		sbi->s_bytesex = BYTESEX_BE;
186 	else
187 		return 0;
188 	switch (fs32_to_cpu(sbi, sbd->s_type)) {
189 	case 1:
190 		sbi->s_type = FSTYPE_XENIX;
191 		return 1;
192 	case 2:
193 		sbi->s_type = FSTYPE_XENIX;
194 		return 2;
195 	default:
196 		return 0;
197 	}
198 }
199 
detect_sysv(struct sysv_sb_info * sbi,struct buffer_head * bh)200 static int detect_sysv(struct sysv_sb_info *sbi, struct buffer_head *bh)
201 {
202 	struct super_block *sb = sbi->s_sb;
203 	/* All relevant fields are at the same offsets in R2 and R4 */
204 	struct sysv4_super_block * sbd;
205 	u32 type;
206 
207 	sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
208 	if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0xfd187e20))
209 		sbi->s_bytesex = BYTESEX_LE;
210 	else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0xfd187e20))
211 		sbi->s_bytesex = BYTESEX_BE;
212 	else
213 		return 0;
214 
215 	type = fs32_to_cpu(sbi, sbd->s_type);
216 
217  	if (fs16_to_cpu(sbi, sbd->s_nfree) == 0xffff) {
218  		sbi->s_type = FSTYPE_AFS;
219 		sbi->s_forced_ro = 1;
220  		if (!sb_rdonly(sb)) {
221  			printk("SysV FS: SCO EAFS on %s detected, "
222  				"forcing read-only mode.\n",
223  				sb->s_id);
224  		}
225  		return type;
226  	}
227 
228 	if (fs32_to_cpu(sbi, sbd->s_time) < JAN_1_1980) {
229 		/* this is likely to happen on SystemV2 FS */
230 		if (type > 3 || type < 1)
231 			return 0;
232 		sbi->s_type = FSTYPE_SYSV2;
233 		return type;
234 	}
235 	if ((type > 3 || type < 1) && (type > 0x30 || type < 0x10))
236 		return 0;
237 
238 	/* On Interactive Unix (ISC) Version 4.0/3.x s_type field = 0x10,
239 	   0x20 or 0x30 indicates that symbolic links and the 14-character
240 	   filename limit is gone. Due to lack of information about this
241            feature read-only mode seems to be a reasonable approach... -KGB */
242 
243 	if (type >= 0x10) {
244 		printk("SysV FS: can't handle long file names on %s, "
245 		       "forcing read-only mode.\n", sb->s_id);
246 		sbi->s_forced_ro = 1;
247 	}
248 
249 	sbi->s_type = FSTYPE_SYSV4;
250 	return type >= 0x10 ? type >> 4 : type;
251 }
252 
detect_coherent(struct sysv_sb_info * sbi,struct buffer_head * bh)253 static int detect_coherent(struct sysv_sb_info *sbi, struct buffer_head *bh)
254 {
255 	struct coh_super_block * sbd;
256 
257 	sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
258 	if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
259 	    || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
260 		return 0;
261 	sbi->s_bytesex = BYTESEX_PDP;
262 	sbi->s_type = FSTYPE_COH;
263 	return 1;
264 }
265 
detect_sysv_odd(struct sysv_sb_info * sbi,struct buffer_head * bh)266 static int detect_sysv_odd(struct sysv_sb_info *sbi, struct buffer_head *bh)
267 {
268 	int size = detect_sysv(sbi, bh);
269 
270 	return size>2 ? 0 : size;
271 }
272 
273 static struct {
274 	int block;
275 	int (*test)(struct sysv_sb_info *, struct buffer_head *);
276 } flavours[] = {
277 	{1, detect_xenix},
278 	{0, detect_sysv},
279 	{0, detect_coherent},
280 	{9, detect_sysv_odd},
281 	{15,detect_sysv_odd},
282 	{18,detect_sysv},
283 };
284 
285 static char *flavour_names[] = {
286 	[FSTYPE_XENIX]	= "Xenix",
287 	[FSTYPE_SYSV4]	= "SystemV",
288 	[FSTYPE_SYSV2]	= "SystemV Release 2",
289 	[FSTYPE_COH]	= "Coherent",
290 	[FSTYPE_V7]	= "V7",
291 	[FSTYPE_AFS]	= "AFS",
292 };
293 
294 static void (*flavour_setup[])(struct sysv_sb_info *, unsigned *) = {
295 	[FSTYPE_XENIX]	= detected_xenix,
296 	[FSTYPE_SYSV4]	= detected_sysv4,
297 	[FSTYPE_SYSV2]	= detected_sysv2,
298 	[FSTYPE_COH]	= detected_coherent,
299 	[FSTYPE_V7]	= detected_v7,
300 	[FSTYPE_AFS]	= detected_sysv4,
301 };
302 
complete_read_super(struct super_block * sb,int silent,int size)303 static int complete_read_super(struct super_block *sb, int silent, int size)
304 {
305 	struct sysv_sb_info *sbi = SYSV_SB(sb);
306 	struct inode *root_inode;
307 	char *found = flavour_names[sbi->s_type];
308 	u_char n_bits = size+8;
309 	int bsize = 1 << n_bits;
310 	int bsize_4 = bsize >> 2;
311 
312 	sbi->s_firstinodezone = 2;
313 
314 	flavour_setup[sbi->s_type](sbi, &sb->s_max_links);
315 
316 	sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
317 	sbi->s_inodes_per_block = bsize >> 6;
318 	sbi->s_inodes_per_block_1 = (bsize >> 6)-1;
319 	sbi->s_inodes_per_block_bits = n_bits-6;
320 	sbi->s_ind_per_block = bsize_4;
321 	sbi->s_ind_per_block_2 = bsize_4*bsize_4;
322 	sbi->s_toobig_block = 10 + bsize_4 * (1 + bsize_4 * (1 + bsize_4));
323 	sbi->s_ind_per_block_bits = n_bits-2;
324 
325 	sbi->s_ninodes = (sbi->s_firstdatazone - sbi->s_firstinodezone)
326 		<< sbi->s_inodes_per_block_bits;
327 
328 	if (!silent)
329 		printk("VFS: Found a %s FS (block size = %ld) on device %s\n",
330 		       found, sb->s_blocksize, sb->s_id);
331 
332 	sb->s_magic = SYSV_MAGIC_BASE + sbi->s_type;
333 	/* set up enough so that it can read an inode */
334 	sb->s_op = &sysv_sops;
335 	if (sbi->s_forced_ro)
336 		sb->s_flags |= SB_RDONLY;
337 	root_inode = sysv_iget(sb, SYSV_ROOT_INO);
338 	if (IS_ERR(root_inode)) {
339 		printk("SysV FS: get root inode failed\n");
340 		return 0;
341 	}
342 	sb->s_root = d_make_root(root_inode);
343 	if (!sb->s_root) {
344 		printk("SysV FS: get root dentry failed\n");
345 		return 0;
346 	}
347 	return 1;
348 }
349 
sysv_fill_super(struct super_block * sb,void * data,int silent)350 static int sysv_fill_super(struct super_block *sb, void *data, int silent)
351 {
352 	struct buffer_head *bh1, *bh = NULL;
353 	struct sysv_sb_info *sbi;
354 	unsigned long blocknr;
355 	int size = 0, i;
356 
357 	BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block));
358 	BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block));
359 	BUILD_BUG_ON(512 != sizeof (struct sysv2_super_block));
360 	BUILD_BUG_ON(500 != sizeof (struct coh_super_block));
361 	BUILD_BUG_ON(64 != sizeof (struct sysv_inode));
362 
363 	sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
364 	if (!sbi)
365 		return -ENOMEM;
366 
367 	sbi->s_sb = sb;
368 	sbi->s_block_base = 0;
369 	mutex_init(&sbi->s_lock);
370 	sb->s_fs_info = sbi;
371 	sb->s_time_min = 0;
372 	sb->s_time_max = U32_MAX;
373 	sb_set_blocksize(sb, BLOCK_SIZE);
374 
375 	for (i = 0; i < ARRAY_SIZE(flavours) && !size; i++) {
376 		brelse(bh);
377 		bh = sb_bread(sb, flavours[i].block);
378 		if (!bh)
379 			continue;
380 		size = flavours[i].test(SYSV_SB(sb), bh);
381 	}
382 
383 	if (!size)
384 		goto Eunknown;
385 
386 	switch (size) {
387 		case 1:
388 			blocknr = bh->b_blocknr << 1;
389 			brelse(bh);
390 			sb_set_blocksize(sb, 512);
391 			bh1 = sb_bread(sb, blocknr);
392 			bh = sb_bread(sb, blocknr + 1);
393 			break;
394 		case 2:
395 			bh1 = bh;
396 			break;
397 		case 3:
398 			blocknr = bh->b_blocknr >> 1;
399 			brelse(bh);
400 			sb_set_blocksize(sb, 2048);
401 			bh1 = bh = sb_bread(sb, blocknr);
402 			break;
403 		default:
404 			goto Ebadsize;
405 	}
406 
407 	if (bh && bh1) {
408 		sbi->s_bh1 = bh1;
409 		sbi->s_bh2 = bh;
410 		if (complete_read_super(sb, silent, size))
411 			return 0;
412 	}
413 
414 	brelse(bh1);
415 	brelse(bh);
416 	sb_set_blocksize(sb, BLOCK_SIZE);
417 	printk("oldfs: cannot read superblock\n");
418 failed:
419 	kfree(sbi);
420 	return -EINVAL;
421 
422 Eunknown:
423 	brelse(bh);
424 	if (!silent)
425 		printk("VFS: unable to find oldfs superblock on device %s\n",
426 			sb->s_id);
427 	goto failed;
428 Ebadsize:
429 	brelse(bh);
430 	if (!silent)
431 		printk("VFS: oldfs: unsupported block size (%dKb)\n",
432 			1<<(size-2));
433 	goto failed;
434 }
435 
v7_sanity_check(struct super_block * sb,struct buffer_head * bh)436 static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh)
437 {
438 	struct v7_super_block *v7sb;
439 	struct sysv_inode *v7i;
440 	struct buffer_head *bh2;
441 	struct sysv_sb_info *sbi;
442 
443 	sbi = sb->s_fs_info;
444 
445 	/* plausibility check on superblock */
446 	v7sb = (struct v7_super_block *) bh->b_data;
447 	if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE ||
448 	    fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD ||
449 	    fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE)
450 		return 0;
451 
452 	/* plausibility check on root inode: it is a directory,
453 	   with a nonzero size that is a multiple of 16 */
454 	bh2 = sb_bread(sb, 2);
455 	if (bh2 == NULL)
456 		return 0;
457 
458 	v7i = (struct sysv_inode *)(bh2->b_data + 64);
459 	if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR ||
460 	    (fs32_to_cpu(sbi, v7i->i_size) == 0) ||
461 	    (fs32_to_cpu(sbi, v7i->i_size) & 017) ||
462 	    (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES *
463 	     sizeof(struct sysv_dir_entry))) {
464 		brelse(bh2);
465 		return 0;
466 	}
467 
468 	brelse(bh2);
469 	return 1;
470 }
471 
v7_fill_super(struct super_block * sb,void * data,int silent)472 static int v7_fill_super(struct super_block *sb, void *data, int silent)
473 {
474 	struct sysv_sb_info *sbi;
475 	struct buffer_head *bh;
476 
477 	if (440 != sizeof (struct v7_super_block))
478 		panic("V7 FS: bad super-block size");
479 	if (64 != sizeof (struct sysv_inode))
480 		panic("sysv fs: bad i-node size");
481 
482 	sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
483 	if (!sbi)
484 		return -ENOMEM;
485 
486 	sbi->s_sb = sb;
487 	sbi->s_block_base = 0;
488 	sbi->s_type = FSTYPE_V7;
489 	mutex_init(&sbi->s_lock);
490 	sb->s_fs_info = sbi;
491 	sb->s_time_min = 0;
492 	sb->s_time_max = U32_MAX;
493 
494 	sb_set_blocksize(sb, 512);
495 
496 	if ((bh = sb_bread(sb, 1)) == NULL) {
497 		if (!silent)
498 			printk("VFS: unable to read V7 FS superblock on "
499 			       "device %s.\n", sb->s_id);
500 		goto failed;
501 	}
502 
503 	/* Try PDP-11 UNIX */
504 	sbi->s_bytesex = BYTESEX_PDP;
505 	if (v7_sanity_check(sb, bh))
506 		goto detected;
507 
508 	/* Try PC/IX, v7/x86 */
509 	sbi->s_bytesex = BYTESEX_LE;
510 	if (v7_sanity_check(sb, bh))
511 		goto detected;
512 
513 	goto failed;
514 
515 detected:
516 	sbi->s_bh1 = bh;
517 	sbi->s_bh2 = bh;
518 	if (complete_read_super(sb, silent, 1))
519 		return 0;
520 
521 failed:
522 	printk(KERN_ERR "VFS: could not find a valid V7 on %s.\n",
523 		sb->s_id);
524 	brelse(bh);
525 	kfree(sbi);
526 	return -EINVAL;
527 }
528 
529 /* Every kernel module contains stuff like this. */
530 
sysv_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)531 static struct dentry *sysv_mount(struct file_system_type *fs_type,
532 	int flags, const char *dev_name, void *data)
533 {
534 	return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super);
535 }
536 
v7_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)537 static struct dentry *v7_mount(struct file_system_type *fs_type,
538 	int flags, const char *dev_name, void *data)
539 {
540 	return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super);
541 }
542 
543 static struct file_system_type sysv_fs_type = {
544 	.owner		= THIS_MODULE,
545 	.name		= "sysv",
546 	.mount		= sysv_mount,
547 	.kill_sb	= kill_block_super,
548 	.fs_flags	= FS_REQUIRES_DEV,
549 };
550 MODULE_ALIAS_FS("sysv");
551 
552 static struct file_system_type v7_fs_type = {
553 	.owner		= THIS_MODULE,
554 	.name		= "v7",
555 	.mount		= v7_mount,
556 	.kill_sb	= kill_block_super,
557 	.fs_flags	= FS_REQUIRES_DEV,
558 };
559 MODULE_ALIAS_FS("v7");
560 MODULE_ALIAS("v7");
561 
init_sysv_fs(void)562 static int __init init_sysv_fs(void)
563 {
564 	int error;
565 
566 	error = sysv_init_icache();
567 	if (error)
568 		goto out;
569 	error = register_filesystem(&sysv_fs_type);
570 	if (error)
571 		goto destroy_icache;
572 	error = register_filesystem(&v7_fs_type);
573 	if (error)
574 		goto unregister;
575 	return 0;
576 
577 unregister:
578 	unregister_filesystem(&sysv_fs_type);
579 destroy_icache:
580 	sysv_destroy_icache();
581 out:
582 	return error;
583 }
584 
exit_sysv_fs(void)585 static void __exit exit_sysv_fs(void)
586 {
587 	unregister_filesystem(&sysv_fs_type);
588 	unregister_filesystem(&v7_fs_type);
589 	sysv_destroy_icache();
590 }
591 
592 module_init(init_sysv_fs)
593 module_exit(exit_sysv_fs)
594 MODULE_LICENSE("GPL");
595 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
596