xref: /linux/fs/qnx6/inode.c (revision 55f1b540d893da740a81200450014c45a8103f54)
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/seq_file.h>
23 #include <linux/crc32.h>
24 #include <linux/mpage.h>
25 #include <linux/fs_parser.h>
26 #include <linux/fs_context.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_reconfigure(struct fs_context *fc);
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 	.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_reconfigure(struct fs_context *fc)
57 {
58 	struct super_block *sb = fc->root->d_sb;
59 
60 	sync_filesystem(sb);
61 	fc->sb_flags |= SB_RDONLY;
62 	return 0;
63 }
64 
65 static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
66 {
67 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
68 	return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
69 }
70 
71 static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
72 
73 static int qnx6_get_block(struct inode *inode, sector_t iblock,
74 			struct buffer_head *bh, int create)
75 {
76 	unsigned phys;
77 
78 	pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n",
79 		 inode->i_ino, (unsigned long)iblock);
80 
81 	phys = qnx6_block_map(inode, iblock);
82 	if (phys) {
83 		/* logical block is before EOF */
84 		map_bh(bh, inode->i_sb, phys);
85 	}
86 	return 0;
87 }
88 
89 static int qnx6_check_blockptr(__fs32 ptr)
90 {
91 	if (ptr == ~(__fs32)0) {
92 		pr_err("hit unused blockpointer.\n");
93 		return 0;
94 	}
95 	return 1;
96 }
97 
98 static int qnx6_read_folio(struct file *file, struct folio *folio)
99 {
100 	return mpage_read_folio(folio, qnx6_get_block);
101 }
102 
103 static void qnx6_readahead(struct readahead_control *rac)
104 {
105 	mpage_readahead(rac, qnx6_get_block);
106 }
107 
108 /*
109  * returns the block number for the no-th element in the tree
110  * inodebits requred as there are multiple inodes in one inode block
111  */
112 static unsigned qnx6_block_map(struct inode *inode, unsigned no)
113 {
114 	struct super_block *s = inode->i_sb;
115 	struct qnx6_sb_info *sbi = QNX6_SB(s);
116 	struct qnx6_inode_info *ei = QNX6_I(inode);
117 	unsigned block = 0;
118 	struct buffer_head *bh;
119 	__fs32 ptr;
120 	int levelptr;
121 	int ptrbits = sbi->s_ptrbits;
122 	int bitdelta;
123 	u32 mask = (1 << ptrbits) - 1;
124 	int depth = ei->di_filelevels;
125 	int i;
126 
127 	bitdelta = ptrbits * depth;
128 	levelptr = no >> bitdelta;
129 
130 	if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) {
131 		pr_err("Requested file block number (%u) too big.", no);
132 		return 0;
133 	}
134 
135 	block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]);
136 
137 	for (i = 0; i < depth; i++) {
138 		bh = sb_bread(s, block);
139 		if (!bh) {
140 			pr_err("Error reading block (%u)\n", block);
141 			return 0;
142 		}
143 		bitdelta -= ptrbits;
144 		levelptr = (no >> bitdelta) & mask;
145 		ptr = ((__fs32 *)bh->b_data)[levelptr];
146 
147 		if (!qnx6_check_blockptr(ptr))
148 			return 0;
149 
150 		block = qnx6_get_devblock(s, ptr);
151 		brelse(bh);
152 	}
153 	return block;
154 }
155 
156 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf)
157 {
158 	struct super_block *sb = dentry->d_sb;
159 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
160 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
161 
162 	buf->f_type    = sb->s_magic;
163 	buf->f_bsize   = sb->s_blocksize;
164 	buf->f_blocks  = fs32_to_cpu(sbi, sbi->sb->sb_num_blocks);
165 	buf->f_bfree   = fs32_to_cpu(sbi, sbi->sb->sb_free_blocks);
166 	buf->f_files   = fs32_to_cpu(sbi, sbi->sb->sb_num_inodes);
167 	buf->f_ffree   = fs32_to_cpu(sbi, sbi->sb->sb_free_inodes);
168 	buf->f_bavail  = buf->f_bfree;
169 	buf->f_namelen = QNX6_LONG_NAME_MAX;
170 	buf->f_fsid    = u64_to_fsid(id);
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 folio *folio = read_mapping_folio(mapping, 0, NULL);
188 
189 	if (IS_ERR(folio))
190 		return "error reading root directory";
191 	dir_entry = kmap_local_folio(folio, 0);
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 	folio_release_kmap(folio, dir_entry);
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 };
224 
225 struct qnx6_context {
226 	unsigned long s_mount_opts;
227 };
228 
229 static const struct fs_parameter_spec qnx6_param_spec[] = {
230 	fsparam_flag	("mmi_fs",	Opt_mmifs),
231 	{}
232 };
233 
234 static int qnx6_parse_param(struct fs_context *fc, struct fs_parameter *param)
235 {
236 	struct qnx6_context *ctx = fc->fs_private;
237 	struct fs_parse_result result;
238 	int opt;
239 
240 	opt = fs_parse(fc, qnx6_param_spec, param, &result);
241 	if (opt < 0)
242 		return opt;
243 
244 	switch (opt) {
245 	case Opt_mmifs:
246 		ctx->s_mount_opts |= QNX6_MOUNT_MMI_FS;
247 		break;
248 	default:
249 		return -EINVAL;
250 	}
251 	return 0;
252 }
253 
254 static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
255 				int offset, int silent)
256 {
257 	struct qnx6_sb_info *sbi = QNX6_SB(s);
258 	struct buffer_head *bh;
259 	struct qnx6_super_block *sb;
260 
261 	/* Check the superblock signatures
262 	   start with the first superblock */
263 	bh = sb_bread(s, offset);
264 	if (!bh) {
265 		pr_err("unable to read the first superblock\n");
266 		return NULL;
267 	}
268 	sb = (struct qnx6_super_block *)bh->b_data;
269 	if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) {
270 		sbi->s_bytesex = BYTESEX_BE;
271 		if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) {
272 			/* we got a big endian fs */
273 			pr_debug("fs got different endianness.\n");
274 			return bh;
275 		} else
276 			sbi->s_bytesex = BYTESEX_LE;
277 		if (!silent) {
278 			if (offset == 0) {
279 				pr_err("wrong signature (magic) in superblock #1.\n");
280 			} else {
281 				pr_info("wrong signature (magic) at position (0x%lx) - will try alternative position (0x0000).\n",
282 					offset * s->s_blocksize);
283 			}
284 		}
285 		brelse(bh);
286 		return NULL;
287 	}
288 	return bh;
289 }
290 
291 static struct inode *qnx6_private_inode(struct super_block *s,
292 					struct qnx6_root_node *p);
293 
294 static int qnx6_fill_super(struct super_block *s, struct fs_context *fc)
295 {
296 	struct buffer_head *bh1 = NULL, *bh2 = NULL;
297 	struct qnx6_super_block *sb1 = NULL, *sb2 = NULL;
298 	struct qnx6_sb_info *sbi;
299 	struct qnx6_context *ctx = fc->fs_private;
300 	struct inode *root;
301 	const char *errmsg;
302 	struct qnx6_sb_info *qs;
303 	int ret = -EINVAL;
304 	u64 offset;
305 	int bootblock_offset = QNX6_BOOTBLOCK_SIZE;
306 	int silent = fc->sb_flags & SB_SILENT;
307 
308 	qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
309 	if (!qs)
310 		return -ENOMEM;
311 	s->s_fs_info = qs;
312 	qs->s_mount_opt = ctx->s_mount_opts;
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 	if (qs->s_mount_opt == QNX6_MOUNT_MMI_FS) {
321 		sb1 = qnx6_mmi_fill_super(s, silent);
322 		if (sb1)
323 			goto mmi_success;
324 		else
325 			goto outnobh;
326 	}
327 	sbi = QNX6_SB(s);
328 	sbi->s_bytesex = BYTESEX_LE;
329 	/* Check the superblock signatures
330 	   start with the first superblock */
331 	bh1 = qnx6_check_first_superblock(s,
332 		bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent);
333 	if (!bh1) {
334 		/* try again without bootblock offset */
335 		bh1 = qnx6_check_first_superblock(s, 0, silent);
336 		if (!bh1) {
337 			pr_err("unable to read the first superblock\n");
338 			goto outnobh;
339 		}
340 		/* seems that no bootblock at partition start */
341 		bootblock_offset = 0;
342 	}
343 	sb1 = (struct qnx6_super_block *)bh1->b_data;
344 
345 #ifdef CONFIG_QNX6FS_DEBUG
346 	qnx6_superblock_debug(sb1, s);
347 #endif
348 
349 	/* checksum check - start at byte 8 and end at byte 512 */
350 	if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
351 			crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
352 		pr_err("superblock #1 checksum error\n");
353 		goto out;
354 	}
355 
356 	/* set new blocksize */
357 	if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
358 		pr_err("unable to set blocksize\n");
359 		goto out;
360 	}
361 	/* blocksize invalidates bh - pull it back in */
362 	brelse(bh1);
363 	bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits);
364 	if (!bh1)
365 		goto outnobh;
366 	sb1 = (struct qnx6_super_block *)bh1->b_data;
367 
368 	/* calculate second superblock blocknumber */
369 	offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) +
370 		(bootblock_offset >> s->s_blocksize_bits) +
371 		(QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
372 
373 	/* set bootblock offset */
374 	sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
375 			  (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
376 
377 	/* next the second superblock */
378 	bh2 = sb_bread(s, offset);
379 	if (!bh2) {
380 		pr_err("unable to read the second superblock\n");
381 		goto out;
382 	}
383 	sb2 = (struct qnx6_super_block *)bh2->b_data;
384 	if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
385 		if (!silent)
386 			pr_err("wrong signature (magic) in superblock #2.\n");
387 		goto out;
388 	}
389 
390 	/* checksum check - start at byte 8 and end at byte 512 */
391 	if (fs32_to_cpu(sbi, sb2->sb_checksum) !=
392 				crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
393 		pr_err("superblock #2 checksum error\n");
394 		goto out;
395 	}
396 
397 	if (fs64_to_cpu(sbi, sb1->sb_serial) >=
398 					fs64_to_cpu(sbi, sb2->sb_serial)) {
399 		/* superblock #1 active */
400 		sbi->sb_buf = bh1;
401 		sbi->sb = (struct qnx6_super_block *)bh1->b_data;
402 		brelse(bh2);
403 		pr_info("superblock #1 active\n");
404 	} else {
405 		/* superblock #2 active */
406 		sbi->sb_buf = bh2;
407 		sbi->sb = (struct qnx6_super_block *)bh2->b_data;
408 		brelse(bh1);
409 		pr_info("superblock #2 active\n");
410 	}
411 mmi_success:
412 	/* sanity check - limit maximum indirect pointer levels */
413 	if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) {
414 		pr_err("too many inode levels (max %i, sb %i)\n",
415 		       QNX6_PTR_MAX_LEVELS, sb1->Inode.levels);
416 		goto out;
417 	}
418 	if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) {
419 		pr_err("too many longfilename levels (max %i, sb %i)\n",
420 		       QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels);
421 		goto out;
422 	}
423 	s->s_op = &qnx6_sops;
424 	s->s_magic = QNX6_SUPER_MAGIC;
425 	s->s_flags |= SB_RDONLY;        /* Yup, read-only yet */
426 	s->s_time_min = 0;
427 	s->s_time_max = U32_MAX;
428 
429 	/* ease the later tree level calculations */
430 	sbi = QNX6_SB(s);
431 	sbi->s_ptrbits = ilog2(s->s_blocksize / 4);
432 	sbi->inodes = qnx6_private_inode(s, &sb1->Inode);
433 	if (!sbi->inodes)
434 		goto out;
435 	sbi->longfile = qnx6_private_inode(s, &sb1->Longfile);
436 	if (!sbi->longfile)
437 		goto out1;
438 
439 	/* prefetch root inode */
440 	root = qnx6_iget(s, QNX6_ROOT_INO);
441 	if (IS_ERR(root)) {
442 		pr_err("get inode failed\n");
443 		ret = PTR_ERR(root);
444 		goto out2;
445 	}
446 
447 	ret = -ENOMEM;
448 	s->s_root = d_make_root(root);
449 	if (!s->s_root)
450 		goto out2;
451 
452 	ret = -EINVAL;
453 	errmsg = qnx6_checkroot(s);
454 	if (errmsg != NULL) {
455 		if (!silent)
456 			pr_err("%s\n", errmsg);
457 		goto out3;
458 	}
459 	return 0;
460 
461 out3:
462 	dput(s->s_root);
463 	s->s_root = NULL;
464 out2:
465 	iput(sbi->longfile);
466 out1:
467 	iput(sbi->inodes);
468 out:
469 	brelse(bh1);
470 	brelse(bh2);
471 outnobh:
472 	kfree(qs);
473 	s->s_fs_info = NULL;
474 	return ret;
475 }
476 
477 static void qnx6_put_super(struct super_block *sb)
478 {
479 	struct qnx6_sb_info *qs = QNX6_SB(sb);
480 	brelse(qs->sb_buf);
481 	iput(qs->longfile);
482 	iput(qs->inodes);
483 	kfree(qs);
484 	sb->s_fs_info = NULL;
485 	return;
486 }
487 
488 static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
489 {
490 	return generic_block_bmap(mapping, block, qnx6_get_block);
491 }
492 static const struct address_space_operations qnx6_aops = {
493 	.read_folio	= qnx6_read_folio,
494 	.readahead	= qnx6_readahead,
495 	.bmap		= qnx6_bmap
496 };
497 
498 static struct inode *qnx6_private_inode(struct super_block *s,
499 					struct qnx6_root_node *p)
500 {
501 	struct inode *inode = new_inode(s);
502 	if (inode) {
503 		struct qnx6_inode_info *ei = QNX6_I(inode);
504 		struct qnx6_sb_info *sbi = QNX6_SB(s);
505 		inode->i_size = fs64_to_cpu(sbi, p->size);
506 		memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr));
507 		ei->di_filelevels = p->levels;
508 		inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */
509 		inode->i_mapping->a_ops = &qnx6_aops;
510 	}
511 	return inode;
512 }
513 
514 struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
515 {
516 	struct qnx6_sb_info *sbi = QNX6_SB(sb);
517 	struct qnx6_inode_entry *raw_inode;
518 	struct inode *inode;
519 	struct qnx6_inode_info	*ei;
520 	struct address_space *mapping;
521 	struct folio *folio;
522 	u32 n, offs;
523 
524 	inode = iget_locked(sb, ino);
525 	if (!inode)
526 		return ERR_PTR(-ENOMEM);
527 	if (!(inode->i_state & I_NEW))
528 		return inode;
529 
530 	ei = QNX6_I(inode);
531 
532 	inode->i_mode = 0;
533 
534 	if (ino == 0) {
535 		pr_err("bad inode number on dev %s: %u is out of range\n",
536 		       sb->s_id, ino);
537 		iget_failed(inode);
538 		return ERR_PTR(-EIO);
539 	}
540 	n = (ino - 1) >> (PAGE_SHIFT - QNX6_INODE_SIZE_BITS);
541 	mapping = sbi->inodes->i_mapping;
542 	folio = read_mapping_folio(mapping, n, NULL);
543 	if (IS_ERR(folio)) {
544 		pr_err("major problem: unable to read inode from dev %s\n",
545 		       sb->s_id);
546 		iget_failed(inode);
547 		return ERR_CAST(folio);
548 	}
549 	offs = offset_in_folio(folio, (ino - 1) << QNX6_INODE_SIZE_BITS);
550 	raw_inode = kmap_local_folio(folio, offs);
551 
552 	inode->i_mode    = fs16_to_cpu(sbi, raw_inode->di_mode);
553 	i_uid_write(inode, (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid));
554 	i_gid_write(inode, (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid));
555 	inode->i_size    = fs64_to_cpu(sbi, raw_inode->di_size);
556 	inode_set_mtime(inode, fs32_to_cpu(sbi, raw_inode->di_mtime), 0);
557 	inode_set_atime(inode, fs32_to_cpu(sbi, raw_inode->di_atime), 0);
558 	inode_set_ctime(inode, fs32_to_cpu(sbi, raw_inode->di_ctime), 0);
559 
560 	/* calc blocks based on 512 byte blocksize */
561 	inode->i_blocks = (inode->i_size + 511) >> 9;
562 
563 	memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr,
564 				sizeof(raw_inode->di_block_ptr));
565 	ei->di_filelevels = raw_inode->di_filelevels;
566 
567 	if (S_ISREG(inode->i_mode)) {
568 		inode->i_fop = &generic_ro_fops;
569 		inode->i_mapping->a_ops = &qnx6_aops;
570 	} else if (S_ISDIR(inode->i_mode)) {
571 		inode->i_op = &qnx6_dir_inode_operations;
572 		inode->i_fop = &qnx6_dir_operations;
573 		inode->i_mapping->a_ops = &qnx6_aops;
574 	} else if (S_ISLNK(inode->i_mode)) {
575 		inode->i_op = &page_symlink_inode_operations;
576 		inode_nohighmem(inode);
577 		inode->i_mapping->a_ops = &qnx6_aops;
578 	} else
579 		init_special_inode(inode, inode->i_mode, 0);
580 	folio_release_kmap(folio, raw_inode);
581 	unlock_new_inode(inode);
582 	return inode;
583 }
584 
585 static struct kmem_cache *qnx6_inode_cachep;
586 
587 static struct inode *qnx6_alloc_inode(struct super_block *sb)
588 {
589 	struct qnx6_inode_info *ei;
590 	ei = alloc_inode_sb(sb, qnx6_inode_cachep, GFP_KERNEL);
591 	if (!ei)
592 		return NULL;
593 	return &ei->vfs_inode;
594 }
595 
596 static void qnx6_free_inode(struct inode *inode)
597 {
598 	kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
599 }
600 
601 static void init_once(void *foo)
602 {
603 	struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
604 
605 	inode_init_once(&ei->vfs_inode);
606 }
607 
608 static int init_inodecache(void)
609 {
610 	qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache",
611 					     sizeof(struct qnx6_inode_info),
612 					     0, (SLAB_RECLAIM_ACCOUNT|
613 						SLAB_ACCOUNT),
614 					     init_once);
615 	if (!qnx6_inode_cachep)
616 		return -ENOMEM;
617 	return 0;
618 }
619 
620 static void destroy_inodecache(void)
621 {
622 	/*
623 	 * Make sure all delayed rcu free inodes are flushed before we
624 	 * destroy cache.
625 	 */
626 	rcu_barrier();
627 	kmem_cache_destroy(qnx6_inode_cachep);
628 }
629 
630 static int qnx6_get_tree(struct fs_context *fc)
631 {
632 	return get_tree_bdev(fc, qnx6_fill_super);
633 }
634 
635 static void qnx6_free_fc(struct fs_context *fc)
636 {
637 	kfree(fc->fs_private);
638 }
639 
640 static const struct fs_context_operations qnx6_context_ops = {
641 	.parse_param	= qnx6_parse_param,
642 	.get_tree	= qnx6_get_tree,
643 	.reconfigure	= qnx6_reconfigure,
644 	.free		= qnx6_free_fc,
645 };
646 
647 static int qnx6_init_fs_context(struct fs_context *fc)
648 {
649 	struct qnx6_context *ctx;
650 
651 	ctx = kzalloc(sizeof(struct qnx6_context), GFP_KERNEL);
652 	if (!ctx)
653 		return -ENOMEM;
654 	fc->ops = &qnx6_context_ops;
655 	fc->fs_private = ctx;
656 
657 	return 0;
658 }
659 
660 static struct file_system_type qnx6_fs_type = {
661 	.owner			= THIS_MODULE,
662 	.name			= "qnx6",
663 	.kill_sb		= kill_block_super,
664 	.fs_flags		= FS_REQUIRES_DEV,
665 	.init_fs_context	= qnx6_init_fs_context,
666 	.parameters		= qnx6_param_spec,
667 };
668 MODULE_ALIAS_FS("qnx6");
669 
670 static int __init init_qnx6_fs(void)
671 {
672 	int err;
673 
674 	err = init_inodecache();
675 	if (err)
676 		return err;
677 
678 	err = register_filesystem(&qnx6_fs_type);
679 	if (err) {
680 		destroy_inodecache();
681 		return err;
682 	}
683 
684 	pr_info("QNX6 filesystem 1.0.0 registered.\n");
685 	return 0;
686 }
687 
688 static void __exit exit_qnx6_fs(void)
689 {
690 	unregister_filesystem(&qnx6_fs_type);
691 	destroy_inodecache();
692 }
693 
694 module_init(init_qnx6_fs)
695 module_exit(exit_qnx6_fs)
696 MODULE_DESCRIPTION("QNX6 file system");
697 MODULE_LICENSE("GPL");
698