xref: /linux/fs/qnx6/inode.c (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
1 /*
2  * QNX6 file system, Linux implementation.
3  *
4  * Version : 1.0.0
5  *
6  * History :
7  *
8  * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
9  * 16-02-2012 pagemap extension by Al Viro
10  *
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/highuid.h>
17 #include <linux/pagemap.h>
18 #include <linux/buffer_head.h>
19 #include <linux/writeback.h>
20 #include <linux/statfs.h>
21 #include <linux/parser.h>
22 #include <linux/seq_file.h>
23 #include <linux/mount.h>
24 #include <linux/crc32.h>
25 #include <linux/mpage.h>
26 #include "qnx6.h"
27 
28 static const struct super_operations qnx6_sops;
29 
30 static void qnx6_put_super(struct super_block *sb);
31 static struct inode *qnx6_alloc_inode(struct super_block *sb);
32 static void qnx6_destroy_inode(struct inode *inode);
33 static int qnx6_remount(struct super_block *sb, int *flags, char *data);
34 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf);
35 static int qnx6_show_options(struct seq_file *seq, struct dentry *root);
36 
37 static const struct super_operations qnx6_sops = {
38 	.alloc_inode	= qnx6_alloc_inode,
39 	.destroy_inode	= qnx6_destroy_inode,
40 	.put_super	= qnx6_put_super,
41 	.statfs		= qnx6_statfs,
42 	.remount_fs	= qnx6_remount,
43 	.show_options	= qnx6_show_options,
44 };
45 
46 static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
47 {
48 	struct super_block *sb = root->d_sb;
49 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
50 
51 	if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS)
52 		seq_puts(seq, ",mmi_fs");
53 	return 0;
54 }
55 
56 static int qnx6_remount(struct super_block *sb, int *flags, char *data)
57 {
58 	sync_filesystem(sb);
59 	*flags |= MS_RDONLY;
60 	return 0;
61 }
62 
63 static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
64 {
65 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
66 	return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
67 }
68 
69 static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
70 
71 static int qnx6_get_block(struct inode *inode, sector_t iblock,
72 			struct buffer_head *bh, int create)
73 {
74 	unsigned phys;
75 
76 	pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n",
77 		 inode->i_ino, (unsigned long)iblock);
78 
79 	phys = qnx6_block_map(inode, iblock);
80 	if (phys) {
81 		/* logical block is before EOF */
82 		map_bh(bh, inode->i_sb, phys);
83 	}
84 	return 0;
85 }
86 
87 static int qnx6_check_blockptr(__fs32 ptr)
88 {
89 	if (ptr == ~(__fs32)0) {
90 		pr_err("hit unused blockpointer.\n");
91 		return 0;
92 	}
93 	return 1;
94 }
95 
96 static int qnx6_readpage(struct file *file, struct page *page)
97 {
98 	return mpage_readpage(page, qnx6_get_block);
99 }
100 
101 static int qnx6_readpages(struct file *file, struct address_space *mapping,
102 		   struct list_head *pages, unsigned nr_pages)
103 {
104 	return mpage_readpages(mapping, pages, nr_pages, 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.val[0] = (u32)id;
170 	buf->f_fsid.val[1] = (u32)(id >> 32);
171 
172 	return 0;
173 }
174 
175 /*
176  * Check the root directory of the filesystem to make sure
177  * it really _is_ a qnx6 filesystem, and to check the size
178  * of the directory entry.
179  */
180 static const char *qnx6_checkroot(struct super_block *s)
181 {
182 	static char match_root[2][3] = {".\0\0", "..\0"};
183 	int i, error = 0;
184 	struct qnx6_dir_entry *dir_entry;
185 	struct inode *root = d_inode(s->s_root);
186 	struct address_space *mapping = root->i_mapping;
187 	struct page *page = read_mapping_page(mapping, 0, NULL);
188 	if (IS_ERR(page))
189 		return "error reading root directory";
190 	kmap(page);
191 	dir_entry = page_address(page);
192 	for (i = 0; i < 2; i++) {
193 		/* maximum 3 bytes - due to match_root limitation */
194 		if (strncmp(dir_entry[i].de_fname, match_root[i], 3))
195 			error = 1;
196 	}
197 	qnx6_put_page(page);
198 	if (error)
199 		return "error reading root directory.";
200 	return NULL;
201 }
202 
203 #ifdef CONFIG_QNX6FS_DEBUG
204 void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s)
205 {
206 	struct qnx6_sb_info *sbi = QNX6_SB(s);
207 
208 	pr_debug("magic: %08x\n", fs32_to_cpu(sbi, sb->sb_magic));
209 	pr_debug("checksum: %08x\n", fs32_to_cpu(sbi, sb->sb_checksum));
210 	pr_debug("serial: %llx\n", fs64_to_cpu(sbi, sb->sb_serial));
211 	pr_debug("flags: %08x\n", fs32_to_cpu(sbi, sb->sb_flags));
212 	pr_debug("blocksize: %08x\n", fs32_to_cpu(sbi, sb->sb_blocksize));
213 	pr_debug("num_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_num_inodes));
214 	pr_debug("free_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_free_inodes));
215 	pr_debug("num_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_num_blocks));
216 	pr_debug("free_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_free_blocks));
217 	pr_debug("inode_levels: %02x\n", sb->Inode.levels);
218 }
219 #endif
220 
221 enum {
222 	Opt_mmifs,
223 	Opt_err
224 };
225 
226 static const match_table_t tokens = {
227 	{Opt_mmifs, "mmi_fs"},
228 	{Opt_err, NULL}
229 };
230 
231 static int qnx6_parse_options(char *options, struct super_block *sb)
232 {
233 	char *p;
234 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
235 	substring_t args[MAX_OPT_ARGS];
236 
237 	if (!options)
238 		return 1;
239 
240 	while ((p = strsep(&options, ",")) != NULL) {
241 		int token;
242 		if (!*p)
243 			continue;
244 
245 		token = match_token(p, tokens, args);
246 		switch (token) {
247 		case Opt_mmifs:
248 			set_opt(sbi->s_mount_opt, MMI_FS);
249 			break;
250 		default:
251 			return 0;
252 		}
253 	}
254 	return 1;
255 }
256 
257 static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
258 				int offset, int silent)
259 {
260 	struct qnx6_sb_info *sbi = QNX6_SB(s);
261 	struct buffer_head *bh;
262 	struct qnx6_super_block *sb;
263 
264 	/* Check the superblock signatures
265 	   start with the first superblock */
266 	bh = sb_bread(s, offset);
267 	if (!bh) {
268 		pr_err("unable to read the first superblock\n");
269 		return NULL;
270 	}
271 	sb = (struct qnx6_super_block *)bh->b_data;
272 	if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) {
273 		sbi->s_bytesex = BYTESEX_BE;
274 		if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) {
275 			/* we got a big endian fs */
276 			pr_debug("fs got different endianness.\n");
277 			return bh;
278 		} else
279 			sbi->s_bytesex = BYTESEX_LE;
280 		if (!silent) {
281 			if (offset == 0) {
282 				pr_err("wrong signature (magic) in superblock #1.\n");
283 			} else {
284 				pr_info("wrong signature (magic) at position (0x%lx) - will try alternative position (0x0000).\n",
285 					offset * s->s_blocksize);
286 			}
287 		}
288 		brelse(bh);
289 		return NULL;
290 	}
291 	return bh;
292 }
293 
294 static struct inode *qnx6_private_inode(struct super_block *s,
295 					struct qnx6_root_node *p);
296 
297 static int qnx6_fill_super(struct super_block *s, void *data, int silent)
298 {
299 	struct buffer_head *bh1 = NULL, *bh2 = NULL;
300 	struct qnx6_super_block *sb1 = NULL, *sb2 = NULL;
301 	struct qnx6_sb_info *sbi;
302 	struct inode *root;
303 	const char *errmsg;
304 	struct qnx6_sb_info *qs;
305 	int ret = -EINVAL;
306 	u64 offset;
307 	int bootblock_offset = QNX6_BOOTBLOCK_SIZE;
308 
309 	qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
310 	if (!qs)
311 		return -ENOMEM;
312 	s->s_fs_info = qs;
313 
314 	/* Superblock always is 512 Byte long */
315 	if (!sb_set_blocksize(s, QNX6_SUPERBLOCK_SIZE)) {
316 		pr_err("unable to set blocksize\n");
317 		goto outnobh;
318 	}
319 
320 	/* parse the mount-options */
321 	if (!qnx6_parse_options((char *) data, s)) {
322 		pr_err("invalid mount options.\n");
323 		goto outnobh;
324 	}
325 	if (test_opt(s, MMI_FS)) {
326 		sb1 = qnx6_mmi_fill_super(s, silent);
327 		if (sb1)
328 			goto mmi_success;
329 		else
330 			goto outnobh;
331 	}
332 	sbi = QNX6_SB(s);
333 	sbi->s_bytesex = BYTESEX_LE;
334 	/* Check the superblock signatures
335 	   start with the first superblock */
336 	bh1 = qnx6_check_first_superblock(s,
337 		bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent);
338 	if (!bh1) {
339 		/* try again without bootblock offset */
340 		bh1 = qnx6_check_first_superblock(s, 0, silent);
341 		if (!bh1) {
342 			pr_err("unable to read the first superblock\n");
343 			goto outnobh;
344 		}
345 		/* seems that no bootblock at partition start */
346 		bootblock_offset = 0;
347 	}
348 	sb1 = (struct qnx6_super_block *)bh1->b_data;
349 
350 #ifdef CONFIG_QNX6FS_DEBUG
351 	qnx6_superblock_debug(sb1, s);
352 #endif
353 
354 	/* checksum check - start at byte 8 and end at byte 512 */
355 	if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
356 			crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
357 		pr_err("superblock #1 checksum error\n");
358 		goto out;
359 	}
360 
361 	/* set new blocksize */
362 	if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
363 		pr_err("unable to set blocksize\n");
364 		goto out;
365 	}
366 	/* blocksize invalidates bh - pull it back in */
367 	brelse(bh1);
368 	bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits);
369 	if (!bh1)
370 		goto outnobh;
371 	sb1 = (struct qnx6_super_block *)bh1->b_data;
372 
373 	/* calculate second superblock blocknumber */
374 	offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) +
375 		(bootblock_offset >> s->s_blocksize_bits) +
376 		(QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
377 
378 	/* set bootblock offset */
379 	sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
380 			  (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
381 
382 	/* next the second superblock */
383 	bh2 = sb_bread(s, offset);
384 	if (!bh2) {
385 		pr_err("unable to read the second superblock\n");
386 		goto out;
387 	}
388 	sb2 = (struct qnx6_super_block *)bh2->b_data;
389 	if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
390 		if (!silent)
391 			pr_err("wrong signature (magic) in superblock #2.\n");
392 		goto out;
393 	}
394 
395 	/* checksum check - start at byte 8 and end at byte 512 */
396 	if (fs32_to_cpu(sbi, sb2->sb_checksum) !=
397 				crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
398 		pr_err("superblock #2 checksum error\n");
399 		goto out;
400 	}
401 
402 	if (fs64_to_cpu(sbi, sb1->sb_serial) >=
403 					fs64_to_cpu(sbi, sb2->sb_serial)) {
404 		/* superblock #1 active */
405 		sbi->sb_buf = bh1;
406 		sbi->sb = (struct qnx6_super_block *)bh1->b_data;
407 		brelse(bh2);
408 		pr_info("superblock #1 active\n");
409 	} else {
410 		/* superblock #2 active */
411 		sbi->sb_buf = bh2;
412 		sbi->sb = (struct qnx6_super_block *)bh2->b_data;
413 		brelse(bh1);
414 		pr_info("superblock #2 active\n");
415 	}
416 mmi_success:
417 	/* sanity check - limit maximum indirect pointer levels */
418 	if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) {
419 		pr_err("too many inode levels (max %i, sb %i)\n",
420 		       QNX6_PTR_MAX_LEVELS, sb1->Inode.levels);
421 		goto out;
422 	}
423 	if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) {
424 		pr_err("too many longfilename levels (max %i, sb %i)\n",
425 		       QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels);
426 		goto out;
427 	}
428 	s->s_op = &qnx6_sops;
429 	s->s_magic = QNX6_SUPER_MAGIC;
430 	s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
431 
432 	/* ease the later tree level calculations */
433 	sbi = QNX6_SB(s);
434 	sbi->s_ptrbits = ilog2(s->s_blocksize / 4);
435 	sbi->inodes = qnx6_private_inode(s, &sb1->Inode);
436 	if (!sbi->inodes)
437 		goto out;
438 	sbi->longfile = qnx6_private_inode(s, &sb1->Longfile);
439 	if (!sbi->longfile)
440 		goto out1;
441 
442 	/* prefetch root inode */
443 	root = qnx6_iget(s, QNX6_ROOT_INO);
444 	if (IS_ERR(root)) {
445 		pr_err("get inode failed\n");
446 		ret = PTR_ERR(root);
447 		goto out2;
448 	}
449 
450 	ret = -ENOMEM;
451 	s->s_root = d_make_root(root);
452 	if (!s->s_root)
453 		goto out2;
454 
455 	ret = -EINVAL;
456 	errmsg = qnx6_checkroot(s);
457 	if (errmsg != NULL) {
458 		if (!silent)
459 			pr_err("%s\n", errmsg);
460 		goto out3;
461 	}
462 	return 0;
463 
464 out3:
465 	dput(s->s_root);
466 	s->s_root = NULL;
467 out2:
468 	iput(sbi->longfile);
469 out1:
470 	iput(sbi->inodes);
471 out:
472 	if (bh1)
473 		brelse(bh1);
474 	if (bh2)
475 		brelse(bh2);
476 outnobh:
477 	kfree(qs);
478 	s->s_fs_info = NULL;
479 	return ret;
480 }
481 
482 static void qnx6_put_super(struct super_block *sb)
483 {
484 	struct qnx6_sb_info *qs = QNX6_SB(sb);
485 	brelse(qs->sb_buf);
486 	iput(qs->longfile);
487 	iput(qs->inodes);
488 	kfree(qs);
489 	sb->s_fs_info = NULL;
490 	return;
491 }
492 
493 static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
494 {
495 	return generic_block_bmap(mapping, block, qnx6_get_block);
496 }
497 static const struct address_space_operations qnx6_aops = {
498 	.readpage	= qnx6_readpage,
499 	.readpages	= qnx6_readpages,
500 	.bmap		= qnx6_bmap
501 };
502 
503 static struct inode *qnx6_private_inode(struct super_block *s,
504 					struct qnx6_root_node *p)
505 {
506 	struct inode *inode = new_inode(s);
507 	if (inode) {
508 		struct qnx6_inode_info *ei = QNX6_I(inode);
509 		struct qnx6_sb_info *sbi = QNX6_SB(s);
510 		inode->i_size = fs64_to_cpu(sbi, p->size);
511 		memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr));
512 		ei->di_filelevels = p->levels;
513 		inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */
514 		inode->i_mapping->a_ops = &qnx6_aops;
515 	}
516 	return inode;
517 }
518 
519 struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
520 {
521 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
522 	struct qnx6_inode_entry *raw_inode;
523 	struct inode *inode;
524 	struct qnx6_inode_info	*ei;
525 	struct address_space *mapping;
526 	struct page *page;
527 	u32 n, offs;
528 
529 	inode = iget_locked(sb, ino);
530 	if (!inode)
531 		return ERR_PTR(-ENOMEM);
532 	if (!(inode->i_state & I_NEW))
533 		return inode;
534 
535 	ei = QNX6_I(inode);
536 
537 	inode->i_mode = 0;
538 
539 	if (ino == 0) {
540 		pr_err("bad inode number on dev %s: %u is out of range\n",
541 		       sb->s_id, ino);
542 		iget_failed(inode);
543 		return ERR_PTR(-EIO);
544 	}
545 	n = (ino - 1) >> (PAGE_CACHE_SHIFT - QNX6_INODE_SIZE_BITS);
546 	offs = (ino - 1) & (~PAGE_CACHE_MASK >> QNX6_INODE_SIZE_BITS);
547 	mapping = sbi->inodes->i_mapping;
548 	page = read_mapping_page(mapping, n, NULL);
549 	if (IS_ERR(page)) {
550 		pr_err("major problem: unable to read inode from dev %s\n",
551 		       sb->s_id);
552 		iget_failed(inode);
553 		return ERR_CAST(page);
554 	}
555 	kmap(page);
556 	raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs;
557 
558 	inode->i_mode    = fs16_to_cpu(sbi, raw_inode->di_mode);
559 	i_uid_write(inode, (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid));
560 	i_gid_write(inode, (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid));
561 	inode->i_size    = fs64_to_cpu(sbi, raw_inode->di_size);
562 	inode->i_mtime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_mtime);
563 	inode->i_mtime.tv_nsec = 0;
564 	inode->i_atime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_atime);
565 	inode->i_atime.tv_nsec = 0;
566 	inode->i_ctime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_ctime);
567 	inode->i_ctime.tv_nsec = 0;
568 
569 	/* calc blocks based on 512 byte blocksize */
570 	inode->i_blocks = (inode->i_size + 511) >> 9;
571 
572 	memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr,
573 				sizeof(raw_inode->di_block_ptr));
574 	ei->di_filelevels = raw_inode->di_filelevels;
575 
576 	if (S_ISREG(inode->i_mode)) {
577 		inode->i_fop = &generic_ro_fops;
578 		inode->i_mapping->a_ops = &qnx6_aops;
579 	} else if (S_ISDIR(inode->i_mode)) {
580 		inode->i_op = &qnx6_dir_inode_operations;
581 		inode->i_fop = &qnx6_dir_operations;
582 		inode->i_mapping->a_ops = &qnx6_aops;
583 	} else if (S_ISLNK(inode->i_mode)) {
584 		inode->i_op = &page_symlink_inode_operations;
585 		inode_nohighmem(inode);
586 		inode->i_mapping->a_ops = &qnx6_aops;
587 	} else
588 		init_special_inode(inode, inode->i_mode, 0);
589 	qnx6_put_page(page);
590 	unlock_new_inode(inode);
591 	return inode;
592 }
593 
594 static struct kmem_cache *qnx6_inode_cachep;
595 
596 static struct inode *qnx6_alloc_inode(struct super_block *sb)
597 {
598 	struct qnx6_inode_info *ei;
599 	ei = kmem_cache_alloc(qnx6_inode_cachep, GFP_KERNEL);
600 	if (!ei)
601 		return NULL;
602 	return &ei->vfs_inode;
603 }
604 
605 static void qnx6_i_callback(struct rcu_head *head)
606 {
607 	struct inode *inode = container_of(head, struct inode, i_rcu);
608 	kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
609 }
610 
611 static void qnx6_destroy_inode(struct inode *inode)
612 {
613 	call_rcu(&inode->i_rcu, qnx6_i_callback);
614 }
615 
616 static void init_once(void *foo)
617 {
618 	struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
619 
620 	inode_init_once(&ei->vfs_inode);
621 }
622 
623 static int init_inodecache(void)
624 {
625 	qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache",
626 					     sizeof(struct qnx6_inode_info),
627 					     0, (SLAB_RECLAIM_ACCOUNT|
628 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
629 					     init_once);
630 	if (!qnx6_inode_cachep)
631 		return -ENOMEM;
632 	return 0;
633 }
634 
635 static void destroy_inodecache(void)
636 {
637 	/*
638 	 * Make sure all delayed rcu free inodes are flushed before we
639 	 * destroy cache.
640 	 */
641 	rcu_barrier();
642 	kmem_cache_destroy(qnx6_inode_cachep);
643 }
644 
645 static struct dentry *qnx6_mount(struct file_system_type *fs_type,
646 	int flags, const char *dev_name, void *data)
647 {
648 	return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super);
649 }
650 
651 static struct file_system_type qnx6_fs_type = {
652 	.owner		= THIS_MODULE,
653 	.name		= "qnx6",
654 	.mount		= qnx6_mount,
655 	.kill_sb	= kill_block_super,
656 	.fs_flags	= FS_REQUIRES_DEV,
657 };
658 MODULE_ALIAS_FS("qnx6");
659 
660 static int __init init_qnx6_fs(void)
661 {
662 	int err;
663 
664 	err = init_inodecache();
665 	if (err)
666 		return err;
667 
668 	err = register_filesystem(&qnx6_fs_type);
669 	if (err) {
670 		destroy_inodecache();
671 		return err;
672 	}
673 
674 	pr_info("QNX6 filesystem 1.0.0 registered.\n");
675 	return 0;
676 }
677 
678 static void __exit exit_qnx6_fs(void)
679 {
680 	unregister_filesystem(&qnx6_fs_type);
681 	destroy_inodecache();
682 }
683 
684 module_init(init_qnx6_fs)
685 module_exit(exit_qnx6_fs)
686 MODULE_LICENSE("GPL");
687