Linux 4.8-rc8
[linux/fpc-iii.git] / fs / qnx6 / inode.c
blob1192422a1c5628e5782961252e2a1bdab58237c7
1 /*
2 * QNX6 file system, Linux implementation.
4 * Version : 1.0.0
6 * History :
8 * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
9 * 16-02-2012 pagemap extension by Al Viro
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"
28 static const struct super_operations qnx6_sops;
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);
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,
46 static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
48 struct super_block *sb = root->d_sb;
49 struct qnx6_sb_info *sbi = QNX6_SB(sb);
51 if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS)
52 seq_puts(seq, ",mmi_fs");
53 return 0;
56 static int qnx6_remount(struct super_block *sb, int *flags, char *data)
58 sync_filesystem(sb);
59 *flags |= MS_RDONLY;
60 return 0;
63 static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
65 struct qnx6_sb_info *sbi = QNX6_SB(sb);
66 return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
69 static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
71 static int qnx6_get_block(struct inode *inode, sector_t iblock,
72 struct buffer_head *bh, int create)
74 unsigned phys;
76 pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n",
77 inode->i_ino, (unsigned long)iblock);
79 phys = qnx6_block_map(inode, iblock);
80 if (phys) {
81 /* logical block is before EOF */
82 map_bh(bh, inode->i_sb, phys);
84 return 0;
87 static int qnx6_check_blockptr(__fs32 ptr)
89 if (ptr == ~(__fs32)0) {
90 pr_err("hit unused blockpointer.\n");
91 return 0;
93 return 1;
96 static int qnx6_readpage(struct file *file, struct page *page)
98 return mpage_readpage(page, qnx6_get_block);
101 static int qnx6_readpages(struct file *file, struct address_space *mapping,
102 struct list_head *pages, unsigned nr_pages)
104 return mpage_readpages(mapping, pages, nr_pages, qnx6_get_block);
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
111 static unsigned qnx6_block_map(struct inode *inode, unsigned no)
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;
126 bitdelta = ptrbits * depth;
127 levelptr = no >> bitdelta;
129 if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) {
130 pr_err("Requested file block number (%u) too big.", no);
131 return 0;
134 block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]);
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;
142 bitdelta -= ptrbits;
143 levelptr = (no >> bitdelta) & mask;
144 ptr = ((__fs32 *)bh->b_data)[levelptr];
146 if (!qnx6_check_blockptr(ptr))
147 return 0;
149 block = qnx6_get_devblock(s, ptr);
150 brelse(bh);
152 return block;
155 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf)
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);
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);
172 return 0;
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.
180 static const char *qnx6_checkroot(struct super_block *s)
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;
197 qnx6_put_page(page);
198 if (error)
199 return "error reading root directory.";
200 return NULL;
203 #ifdef CONFIG_QNX6FS_DEBUG
204 void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s)
206 struct qnx6_sb_info *sbi = QNX6_SB(s);
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);
219 #endif
221 enum {
222 Opt_mmifs,
223 Opt_err
226 static const match_table_t tokens = {
227 {Opt_mmifs, "mmi_fs"},
228 {Opt_err, NULL}
231 static int qnx6_parse_options(char *options, struct super_block *sb)
233 char *p;
234 struct qnx6_sb_info *sbi = QNX6_SB(sb);
235 substring_t args[MAX_OPT_ARGS];
237 if (!options)
238 return 1;
240 while ((p = strsep(&options, ",")) != NULL) {
241 int token;
242 if (!*p)
243 continue;
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;
254 return 1;
257 static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
258 int offset, int silent)
260 struct qnx6_sb_info *sbi = QNX6_SB(s);
261 struct buffer_head *bh;
262 struct qnx6_super_block *sb;
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;
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);
288 brelse(bh);
289 return NULL;
291 return bh;
294 static struct inode *qnx6_private_inode(struct super_block *s,
295 struct qnx6_root_node *p);
297 static int qnx6_fill_super(struct super_block *s, void *data, int silent)
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;
309 qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
310 if (!qs)
311 return -ENOMEM;
312 s->s_fs_info = qs;
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;
320 /* parse the mount-options */
321 if (!qnx6_parse_options((char *) data, s)) {
322 pr_err("invalid mount options.\n");
323 goto outnobh;
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;
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;
345 /* seems that no bootblock at partition start */
346 bootblock_offset = 0;
348 sb1 = (struct qnx6_super_block *)bh1->b_data;
350 #ifdef CONFIG_QNX6FS_DEBUG
351 qnx6_superblock_debug(sb1, s);
352 #endif
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;
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;
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;
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);
378 /* set bootblock offset */
379 sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
380 (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
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;
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;
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;
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");
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;
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;
428 s->s_op = &qnx6_sops;
429 s->s_magic = QNX6_SUPER_MAGIC;
430 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
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;
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;
450 ret = -ENOMEM;
451 s->s_root = d_make_root(root);
452 if (!s->s_root)
453 goto out2;
455 ret = -EINVAL;
456 errmsg = qnx6_checkroot(s);
457 if (errmsg != NULL) {
458 if (!silent)
459 pr_err("%s\n", errmsg);
460 goto out3;
462 return 0;
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;
482 static void qnx6_put_super(struct super_block *sb)
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;
493 static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
495 return generic_block_bmap(mapping, block, qnx6_get_block);
497 static const struct address_space_operations qnx6_aops = {
498 .readpage = qnx6_readpage,
499 .readpages = qnx6_readpages,
500 .bmap = qnx6_bmap
503 static struct inode *qnx6_private_inode(struct super_block *s,
504 struct qnx6_root_node *p)
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;
516 return inode;
519 struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
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;
529 inode = iget_locked(sb, ino);
530 if (!inode)
531 return ERR_PTR(-ENOMEM);
532 if (!(inode->i_state & I_NEW))
533 return inode;
535 ei = QNX6_I(inode);
537 inode->i_mode = 0;
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);
545 n = (ino - 1) >> (PAGE_SHIFT - QNX6_INODE_SIZE_BITS);
546 offs = (ino - 1) & (~PAGE_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);
555 kmap(page);
556 raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs;
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;
569 /* calc blocks based on 512 byte blocksize */
570 inode->i_blocks = (inode->i_size + 511) >> 9;
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;
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;
594 static struct kmem_cache *qnx6_inode_cachep;
596 static struct inode *qnx6_alloc_inode(struct super_block *sb)
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;
605 static void qnx6_i_callback(struct rcu_head *head)
607 struct inode *inode = container_of(head, struct inode, i_rcu);
608 kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
611 static void qnx6_destroy_inode(struct inode *inode)
613 call_rcu(&inode->i_rcu, qnx6_i_callback);
616 static void init_once(void *foo)
618 struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
620 inode_init_once(&ei->vfs_inode);
623 static int init_inodecache(void)
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;
635 static void destroy_inodecache(void)
638 * Make sure all delayed rcu free inodes are flushed before we
639 * destroy cache.
641 rcu_barrier();
642 kmem_cache_destroy(qnx6_inode_cachep);
645 static struct dentry *qnx6_mount(struct file_system_type *fs_type,
646 int flags, const char *dev_name, void *data)
648 return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super);
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,
658 MODULE_ALIAS_FS("qnx6");
660 static int __init init_qnx6_fs(void)
662 int err;
664 err = init_inodecache();
665 if (err)
666 return err;
668 err = register_filesystem(&qnx6_fs_type);
669 if (err) {
670 destroy_inodecache();
671 return err;
674 pr_info("QNX6 filesystem 1.0.0 registered.\n");
675 return 0;
678 static void __exit exit_qnx6_fs(void)
680 unregister_filesystem(&qnx6_fs_type);
681 destroy_inodecache();
684 module_init(init_qnx6_fs)
685 module_exit(exit_qnx6_fs)
686 MODULE_LICENSE("GPL");