xref: /openbmc/linux/fs/qnx6/inode.c (revision e40573a4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * QNX6 file system, Linux implementation.
4  *
5  * Version : 1.0.0
6  *
7  * History :
8  *
9  * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
10  * 16-02-2012 pagemap extension by Al Viro
11  *
12  */
13 
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/highuid.h>
18 #include <linux/pagemap.h>
19 #include <linux/buffer_head.h>
20 #include <linux/writeback.h>
21 #include <linux/statfs.h>
22 #include <linux/parser.h>
23 #include <linux/seq_file.h>
24 #include <linux/mount.h>
25 #include <linux/crc32.h>
26 #include <linux/mpage.h>
27 #include "qnx6.h"
28 
29 static const struct super_operations qnx6_sops;
30 
31 static void qnx6_put_super(struct super_block *sb);
32 static struct inode *qnx6_alloc_inode(struct super_block *sb);
33 static void qnx6_free_inode(struct inode *inode);
34 static int qnx6_remount(struct super_block *sb, int *flags, char *data);
35 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf);
36 static int qnx6_show_options(struct seq_file *seq, struct dentry *root);
37 
38 static const struct super_operations qnx6_sops = {
39 	.alloc_inode	= qnx6_alloc_inode,
40 	.free_inode	= qnx6_free_inode,
41 	.put_super	= qnx6_put_super,
42 	.statfs		= qnx6_statfs,
43 	.remount_fs	= qnx6_remount,
44 	.show_options	= qnx6_show_options,
45 };
46 
47 static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
48 {
49 	struct super_block *sb = root->d_sb;
50 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
51 
52 	if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS)
53 		seq_puts(seq, ",mmi_fs");
54 	return 0;
55 }
56 
57 static int qnx6_remount(struct super_block *sb, int *flags, char *data)
58 {
59 	sync_filesystem(sb);
60 	*flags |= SB_RDONLY;
61 	return 0;
62 }
63 
64 static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
65 {
66 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
67 	return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
68 }
69 
70 static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
71 
72 static int qnx6_get_block(struct inode *inode, sector_t iblock,
73 			struct buffer_head *bh, int create)
74 {
75 	unsigned phys;
76 
77 	pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n",
78 		 inode->i_ino, (unsigned long)iblock);
79 
80 	phys = qnx6_block_map(inode, iblock);
81 	if (phys) {
82 		/* logical block is before EOF */
83 		map_bh(bh, inode->i_sb, phys);
84 	}
85 	return 0;
86 }
87 
88 static int qnx6_check_blockptr(__fs32 ptr)
89 {
90 	if (ptr == ~(__fs32)0) {
91 		pr_err("hit unused blockpointer.\n");
92 		return 0;
93 	}
94 	return 1;
95 }
96 
97 static int qnx6_read_folio(struct file *file, struct folio *folio)
98 {
99 	return mpage_read_folio(folio, qnx6_get_block);
100 }
101 
102 static void qnx6_readahead(struct readahead_control *rac)
103 {
104 	mpage_readahead(rac, qnx6_get_block);
105 }
106 
107 /*
108  * returns the block number for the no-th element in the tree
109  * inodebits requred as there are multiple inodes in one inode block
110  */
111 static unsigned qnx6_block_map(struct inode *inode, unsigned no)
112 {
113 	struct super_block *s = inode->i_sb;
114 	struct qnx6_sb_info *sbi = QNX6_SB(s);
115 	struct qnx6_inode_info *ei = QNX6_I(inode);
116 	unsigned block = 0;
117 	struct buffer_head *bh;
118 	__fs32 ptr;
119 	int levelptr;
120 	int ptrbits = sbi->s_ptrbits;
121 	int bitdelta;
122 	u32 mask = (1 << ptrbits) - 1;
123 	int depth = ei->di_filelevels;
124 	int i;
125 
126 	bitdelta = ptrbits * depth;
127 	levelptr = no >> bitdelta;
128 
129 	if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) {
130 		pr_err("Requested file block number (%u) too big.", no);
131 		return 0;
132 	}
133 
134 	block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]);
135 
136 	for (i = 0; i < depth; i++) {
137 		bh = sb_bread(s, block);
138 		if (!bh) {
139 			pr_err("Error reading block (%u)\n", block);
140 			return 0;
141 		}
142 		bitdelta -= ptrbits;
143 		levelptr = (no >> bitdelta) & mask;
144 		ptr = ((__fs32 *)bh->b_data)[levelptr];
145 
146 		if (!qnx6_check_blockptr(ptr))
147 			return 0;
148 
149 		block = qnx6_get_devblock(s, ptr);
150 		brelse(bh);
151 	}
152 	return block;
153 }
154 
155 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf)
156 {
157 	struct super_block *sb = dentry->d_sb;
158 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
159 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
160 
161 	buf->f_type    = sb->s_magic;
162 	buf->f_bsize   = sb->s_blocksize;
163 	buf->f_blocks  = fs32_to_cpu(sbi, sbi->sb->sb_num_blocks);
164 	buf->f_bfree   = fs32_to_cpu(sbi, sbi->sb->sb_free_blocks);
165 	buf->f_files   = fs32_to_cpu(sbi, sbi->sb->sb_num_inodes);
166 	buf->f_ffree   = fs32_to_cpu(sbi, sbi->sb->sb_free_inodes);
167 	buf->f_bavail  = buf->f_bfree;
168 	buf->f_namelen = QNX6_LONG_NAME_MAX;
169 	buf->f_fsid    = u64_to_fsid(id);
170 
171 	return 0;
172 }
173 
174 /*
175  * Check the root directory of the filesystem to make sure
176  * it really _is_ a qnx6 filesystem, and to check the size
177  * of the directory entry.
178  */
179 static const char *qnx6_checkroot(struct super_block *s)
180 {
181 	static char match_root[2][3] = {".\0\0", "..\0"};
182 	int i, error = 0;
183 	struct qnx6_dir_entry *dir_entry;
184 	struct inode *root = d_inode(s->s_root);
185 	struct address_space *mapping = root->i_mapping;
186 	struct page *page = read_mapping_page(mapping, 0, NULL);
187 	if (IS_ERR(page))
188 		return "error reading root directory";
189 	kmap(page);
190 	dir_entry = page_address(page);
191 	for (i = 0; i < 2; i++) {
192 		/* maximum 3 bytes - due to match_root limitation */
193 		if (strncmp(dir_entry[i].de_fname, match_root[i], 3))
194 			error = 1;
195 	}
196 	qnx6_put_page(page);
197 	if (error)
198 		return "error reading root directory.";
199 	return NULL;
200 }
201 
202 #ifdef CONFIG_QNX6FS_DEBUG
203 void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s)
204 {
205 	struct qnx6_sb_info *sbi = QNX6_SB(s);
206 
207 	pr_debug("magic: %08x\n", fs32_to_cpu(sbi, sb->sb_magic));
208 	pr_debug("checksum: %08x\n", fs32_to_cpu(sbi, sb->sb_checksum));
209 	pr_debug("serial: %llx\n", fs64_to_cpu(sbi, sb->sb_serial));
210 	pr_debug("flags: %08x\n", fs32_to_cpu(sbi, sb->sb_flags));
211 	pr_debug("blocksize: %08x\n", fs32_to_cpu(sbi, sb->sb_blocksize));
212 	pr_debug("num_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_num_inodes));
213 	pr_debug("free_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_free_inodes));
214 	pr_debug("num_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_num_blocks));
215 	pr_debug("free_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_free_blocks));
216 	pr_debug("inode_levels: %02x\n", sb->Inode.levels);
217 }
218 #endif
219 
220 enum {
221 	Opt_mmifs,
222 	Opt_err
223 };
224 
225 static const match_table_t tokens = {
226 	{Opt_mmifs, "mmi_fs"},
227 	{Opt_err, NULL}
228 };
229 
230 static int qnx6_parse_options(char *options, struct super_block *sb)
231 {
232 	char *p;
233 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
234 	substring_t args[MAX_OPT_ARGS];
235 
236 	if (!options)
237 		return 1;
238 
239 	while ((p = strsep(&options, ",")) != NULL) {
240 		int token;
241 		if (!*p)
242 			continue;
243 
244 		token = match_token(p, tokens, args);
245 		switch (token) {
246 		case Opt_mmifs:
247 			set_opt(sbi->s_mount_opt, MMI_FS);
248 			break;
249 		default:
250 			return 0;
251 		}
252 	}
253 	return 1;
254 }
255 
256 static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
257 				int offset, int silent)
258 {
259 	struct qnx6_sb_info *sbi = QNX6_SB(s);
260 	struct buffer_head *bh;
261 	struct qnx6_super_block *sb;
262 
263 	/* Check the superblock signatures
264 	   start with the first superblock */
265 	bh = sb_bread(s, offset);
266 	if (!bh) {
267 		pr_err("unable to read the first superblock\n");
268 		return NULL;
269 	}
270 	sb = (struct qnx6_super_block *)bh->b_data;
271 	if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) {
272 		sbi->s_bytesex = BYTESEX_BE;
273 		if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) {
274 			/* we got a big endian fs */
275 			pr_debug("fs got different endianness.\n");
276 			return bh;
277 		} else
278 			sbi->s_bytesex = BYTESEX_LE;
279 		if (!silent) {
280 			if (offset == 0) {
281 				pr_err("wrong signature (magic) in superblock #1.\n");
282 			} else {
283 				pr_info("wrong signature (magic) at position (0x%lx) - will try alternative position (0x0000).\n",
284 					offset * s->s_blocksize);
285 			}
286 		}
287 		brelse(bh);
288 		return NULL;
289 	}
290 	return bh;
291 }
292 
293 static struct inode *qnx6_private_inode(struct super_block *s,
294 					struct qnx6_root_node *p);
295 
296 static int qnx6_fill_super(struct super_block *s, void *data, int silent)
297 {
298 	struct buffer_head *bh1 = NULL, *bh2 = NULL;
299 	struct qnx6_super_block *sb1 = NULL, *sb2 = NULL;
300 	struct qnx6_sb_info *sbi;
301 	struct inode *root;
302 	const char *errmsg;
303 	struct qnx6_sb_info *qs;
304 	int ret = -EINVAL;
305 	u64 offset;
306 	int bootblock_offset = QNX6_BOOTBLOCK_SIZE;
307 
308 	qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
309 	if (!qs)
310 		return -ENOMEM;
311 	s->s_fs_info = qs;
312 
313 	/* Superblock always is 512 Byte long */
314 	if (!sb_set_blocksize(s, QNX6_SUPERBLOCK_SIZE)) {
315 		pr_err("unable to set blocksize\n");
316 		goto outnobh;
317 	}
318 
319 	/* parse the mount-options */
320 	if (!qnx6_parse_options((char *) data, s)) {
321 		pr_err("invalid mount options.\n");
322 		goto outnobh;
323 	}
324 	if (test_opt(s, MMI_FS)) {
325 		sb1 = qnx6_mmi_fill_super(s, silent);
326 		if (sb1)
327 			goto mmi_success;
328 		else
329 			goto outnobh;
330 	}
331 	sbi = QNX6_SB(s);
332 	sbi->s_bytesex = BYTESEX_LE;
333 	/* Check the superblock signatures
334 	   start with the first superblock */
335 	bh1 = qnx6_check_first_superblock(s,
336 		bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent);
337 	if (!bh1) {
338 		/* try again without bootblock offset */
339 		bh1 = qnx6_check_first_superblock(s, 0, silent);
340 		if (!bh1) {
341 			pr_err("unable to read the first superblock\n");
342 			goto outnobh;
343 		}
344 		/* seems that no bootblock at partition start */
345 		bootblock_offset = 0;
346 	}
347 	sb1 = (struct qnx6_super_block *)bh1->b_data;
348 
349 #ifdef CONFIG_QNX6FS_DEBUG
350 	qnx6_superblock_debug(sb1, s);
351 #endif
352 
353 	/* checksum check - start at byte 8 and end at byte 512 */
354 	if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
355 			crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
356 		pr_err("superblock #1 checksum error\n");
357 		goto out;
358 	}
359 
360 	/* set new blocksize */
361 	if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
362 		pr_err("unable to set blocksize\n");
363 		goto out;
364 	}
365 	/* blocksize invalidates bh - pull it back in */
366 	brelse(bh1);
367 	bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits);
368 	if (!bh1)
369 		goto outnobh;
370 	sb1 = (struct qnx6_super_block *)bh1->b_data;
371 
372 	/* calculate second superblock blocknumber */
373 	offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) +
374 		(bootblock_offset >> s->s_blocksize_bits) +
375 		(QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
376 
377 	/* set bootblock offset */
378 	sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
379 			  (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
380 
381 	/* next the second superblock */
382 	bh2 = sb_bread(s, offset);
383 	if (!bh2) {
384 		pr_err("unable to read the second superblock\n");
385 		goto out;
386 	}
387 	sb2 = (struct qnx6_super_block *)bh2->b_data;
388 	if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
389 		if (!silent)
390 			pr_err("wrong signature (magic) in superblock #2.\n");
391 		goto out;
392 	}
393 
394 	/* checksum check - start at byte 8 and end at byte 512 */
395 	if (fs32_to_cpu(sbi, sb2->sb_checksum) !=
396 				crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
397 		pr_err("superblock #2 checksum error\n");
398 		goto out;
399 	}
400 
401 	if (fs64_to_cpu(sbi, sb1->sb_serial) >=
402 					fs64_to_cpu(sbi, sb2->sb_serial)) {
403 		/* superblock #1 active */
404 		sbi->sb_buf = bh1;
405 		sbi->sb = (struct qnx6_super_block *)bh1->b_data;
406 		brelse(bh2);
407 		pr_info("superblock #1 active\n");
408 	} else {
409 		/* superblock #2 active */
410 		sbi->sb_buf = bh2;
411 		sbi->sb = (struct qnx6_super_block *)bh2->b_data;
412 		brelse(bh1);
413 		pr_info("superblock #2 active\n");
414 	}
415 mmi_success:
416 	/* sanity check - limit maximum indirect pointer levels */
417 	if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) {
418 		pr_err("too many inode levels (max %i, sb %i)\n",
419 		       QNX6_PTR_MAX_LEVELS, sb1->Inode.levels);
420 		goto out;
421 	}
422 	if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) {
423 		pr_err("too many longfilename levels (max %i, sb %i)\n",
424 		       QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels);
425 		goto out;
426 	}
427 	s->s_op = &qnx6_sops;
428 	s->s_magic = QNX6_SUPER_MAGIC;
429 	s->s_flags |= SB_RDONLY;        /* Yup, read-only yet */
430 	s->s_time_min = 0;
431 	s->s_time_max = U32_MAX;
432 
433 	/* ease the later tree level calculations */
434 	sbi = QNX6_SB(s);
435 	sbi->s_ptrbits = ilog2(s->s_blocksize / 4);
436 	sbi->inodes = qnx6_private_inode(s, &sb1->Inode);
437 	if (!sbi->inodes)
438 		goto out;
439 	sbi->longfile = qnx6_private_inode(s, &sb1->Longfile);
440 	if (!sbi->longfile)
441 		goto out1;
442 
443 	/* prefetch root inode */
444 	root = qnx6_iget(s, QNX6_ROOT_INO);
445 	if (IS_ERR(root)) {
446 		pr_err("get inode failed\n");
447 		ret = PTR_ERR(root);
448 		goto out2;
449 	}
450 
451 	ret = -ENOMEM;
452 	s->s_root = d_make_root(root);
453 	if (!s->s_root)
454 		goto out2;
455 
456 	ret = -EINVAL;
457 	errmsg = qnx6_checkroot(s);
458 	if (errmsg != NULL) {
459 		if (!silent)
460 			pr_err("%s\n", errmsg);
461 		goto out3;
462 	}
463 	return 0;
464 
465 out3:
466 	dput(s->s_root);
467 	s->s_root = NULL;
468 out2:
469 	iput(sbi->longfile);
470 out1:
471 	iput(sbi->inodes);
472 out:
473 	if (bh1)
474 		brelse(bh1);
475 	if (bh2)
476 		brelse(bh2);
477 outnobh:
478 	kfree(qs);
479 	s->s_fs_info = NULL;
480 	return ret;
481 }
482 
483 static void qnx6_put_super(struct super_block *sb)
484 {
485 	struct qnx6_sb_info *qs = QNX6_SB(sb);
486 	brelse(qs->sb_buf);
487 	iput(qs->longfile);
488 	iput(qs->inodes);
489 	kfree(qs);
490 	sb->s_fs_info = NULL;
491 	return;
492 }
493 
494 static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
495 {
496 	return generic_block_bmap(mapping, block, qnx6_get_block);
497 }
498 static const struct address_space_operations qnx6_aops = {
499 	.read_folio	= qnx6_read_folio,
500 	.readahead	= qnx6_readahead,
501 	.bmap		= qnx6_bmap
502 };
503 
504 static struct inode *qnx6_private_inode(struct super_block *s,
505 					struct qnx6_root_node *p)
506 {
507 	struct inode *inode = new_inode(s);
508 	if (inode) {
509 		struct qnx6_inode_info *ei = QNX6_I(inode);
510 		struct qnx6_sb_info *sbi = QNX6_SB(s);
511 		inode->i_size = fs64_to_cpu(sbi, p->size);
512 		memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr));
513 		ei->di_filelevels = p->levels;
514 		inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */
515 		inode->i_mapping->a_ops = &qnx6_aops;
516 	}
517 	return inode;
518 }
519 
520 struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
521 {
522 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
523 	struct qnx6_inode_entry *raw_inode;
524 	struct inode *inode;
525 	struct qnx6_inode_info	*ei;
526 	struct address_space *mapping;
527 	struct page *page;
528 	u32 n, offs;
529 
530 	inode = iget_locked(sb, ino);
531 	if (!inode)
532 		return ERR_PTR(-ENOMEM);
533 	if (!(inode->i_state & I_NEW))
534 		return inode;
535 
536 	ei = QNX6_I(inode);
537 
538 	inode->i_mode = 0;
539 
540 	if (ino == 0) {
541 		pr_err("bad inode number on dev %s: %u is out of range\n",
542 		       sb->s_id, ino);
543 		iget_failed(inode);
544 		return ERR_PTR(-EIO);
545 	}
546 	n = (ino - 1) >> (PAGE_SHIFT - QNX6_INODE_SIZE_BITS);
547 	offs = (ino - 1) & (~PAGE_MASK >> QNX6_INODE_SIZE_BITS);
548 	mapping = sbi->inodes->i_mapping;
549 	page = read_mapping_page(mapping, n, NULL);
550 	if (IS_ERR(page)) {
551 		pr_err("major problem: unable to read inode from dev %s\n",
552 		       sb->s_id);
553 		iget_failed(inode);
554 		return ERR_CAST(page);
555 	}
556 	kmap(page);
557 	raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs;
558 
559 	inode->i_mode    = fs16_to_cpu(sbi, raw_inode->di_mode);
560 	i_uid_write(inode, (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid));
561 	i_gid_write(inode, (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid));
562 	inode->i_size    = fs64_to_cpu(sbi, raw_inode->di_size);
563 	inode->i_mtime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_mtime);
564 	inode->i_mtime.tv_nsec = 0;
565 	inode->i_atime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_atime);
566 	inode->i_atime.tv_nsec = 0;
567 	inode->i_ctime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_ctime);
568 	inode->i_ctime.tv_nsec = 0;
569 
570 	/* calc blocks based on 512 byte blocksize */
571 	inode->i_blocks = (inode->i_size + 511) >> 9;
572 
573 	memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr,
574 				sizeof(raw_inode->di_block_ptr));
575 	ei->di_filelevels = raw_inode->di_filelevels;
576 
577 	if (S_ISREG(inode->i_mode)) {
578 		inode->i_fop = &generic_ro_fops;
579 		inode->i_mapping->a_ops = &qnx6_aops;
580 	} else if (S_ISDIR(inode->i_mode)) {
581 		inode->i_op = &qnx6_dir_inode_operations;
582 		inode->i_fop = &qnx6_dir_operations;
583 		inode->i_mapping->a_ops = &qnx6_aops;
584 	} else if (S_ISLNK(inode->i_mode)) {
585 		inode->i_op = &page_symlink_inode_operations;
586 		inode_nohighmem(inode);
587 		inode->i_mapping->a_ops = &qnx6_aops;
588 	} else
589 		init_special_inode(inode, inode->i_mode, 0);
590 	qnx6_put_page(page);
591 	unlock_new_inode(inode);
592 	return inode;
593 }
594 
595 static struct kmem_cache *qnx6_inode_cachep;
596 
597 static struct inode *qnx6_alloc_inode(struct super_block *sb)
598 {
599 	struct qnx6_inode_info *ei;
600 	ei = alloc_inode_sb(sb, qnx6_inode_cachep, GFP_KERNEL);
601 	if (!ei)
602 		return NULL;
603 	return &ei->vfs_inode;
604 }
605 
606 static void qnx6_free_inode(struct inode *inode)
607 {
608 	kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
609 }
610 
611 static void init_once(void *foo)
612 {
613 	struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
614 
615 	inode_init_once(&ei->vfs_inode);
616 }
617 
618 static int init_inodecache(void)
619 {
620 	qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache",
621 					     sizeof(struct qnx6_inode_info),
622 					     0, (SLAB_RECLAIM_ACCOUNT|
623 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
624 					     init_once);
625 	if (!qnx6_inode_cachep)
626 		return -ENOMEM;
627 	return 0;
628 }
629 
630 static void destroy_inodecache(void)
631 {
632 	/*
633 	 * Make sure all delayed rcu free inodes are flushed before we
634 	 * destroy cache.
635 	 */
636 	rcu_barrier();
637 	kmem_cache_destroy(qnx6_inode_cachep);
638 }
639 
640 static struct dentry *qnx6_mount(struct file_system_type *fs_type,
641 	int flags, const char *dev_name, void *data)
642 {
643 	return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super);
644 }
645 
646 static struct file_system_type qnx6_fs_type = {
647 	.owner		= THIS_MODULE,
648 	.name		= "qnx6",
649 	.mount		= qnx6_mount,
650 	.kill_sb	= kill_block_super,
651 	.fs_flags	= FS_REQUIRES_DEV,
652 };
653 MODULE_ALIAS_FS("qnx6");
654 
655 static int __init init_qnx6_fs(void)
656 {
657 	int err;
658 
659 	err = init_inodecache();
660 	if (err)
661 		return err;
662 
663 	err = register_filesystem(&qnx6_fs_type);
664 	if (err) {
665 		destroy_inodecache();
666 		return err;
667 	}
668 
669 	pr_info("QNX6 filesystem 1.0.0 registered.\n");
670 	return 0;
671 }
672 
673 static void __exit exit_qnx6_fs(void)
674 {
675 	unregister_filesystem(&qnx6_fs_type);
676 	destroy_inodecache();
677 }
678 
679 module_init(init_qnx6_fs)
680 module_exit(exit_qnx6_fs)
681 MODULE_LICENSE("GPL");
682