xref: /openbmc/linux/fs/qnx4/inode.c (revision b627b4ed)
1 /*
2  * QNX4 file system, Linux implementation.
3  *
4  * Version : 0.2.1
5  *
6  * Using parts of the xiafs filesystem.
7  *
8  * History :
9  *
10  * 01-06-1998 by Richard Frowijn : first release.
11  * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
12  * 30-06-1998 by Frank Denis : first step to write inodes.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <linux/fs.h>
21 #include <linux/qnx4_fs.h>
22 #include <linux/init.h>
23 #include <linux/highuid.h>
24 #include <linux/smp_lock.h>
25 #include <linux/pagemap.h>
26 #include <linux/buffer_head.h>
27 #include <linux/vfs.h>
28 #include <asm/uaccess.h>
29 
30 #define QNX4_VERSION  4
31 #define QNX4_BMNAME   ".bitmap"
32 
33 static const struct super_operations qnx4_sops;
34 
35 #ifdef CONFIG_QNX4FS_RW
36 
37 int qnx4_sync_inode(struct inode *inode)
38 {
39 	int err = 0;
40 # if 0
41 	struct buffer_head *bh;
42 
43    	bh = qnx4_update_inode(inode);
44 	if (bh && buffer_dirty(bh))
45 	{
46 		sync_dirty_buffer(bh);
47 		if (buffer_req(bh) && !buffer_uptodate(bh))
48 		{
49 			printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
50 				inode->i_sb->s_id, inode->i_ino);
51 			err = -1;
52 		}
53 	        brelse (bh);
54 	} else if (!bh) {
55 		err = -1;
56 	}
57 # endif
58 
59 	return err;
60 }
61 
62 static void qnx4_delete_inode(struct inode *inode)
63 {
64 	QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
65 	truncate_inode_pages(&inode->i_data, 0);
66 	inode->i_size = 0;
67 	qnx4_truncate(inode);
68 	lock_kernel();
69 	qnx4_free_inode(inode);
70 	unlock_kernel();
71 }
72 
73 static void qnx4_write_super(struct super_block *sb)
74 {
75 	lock_kernel();
76 	QNX4DEBUG(("qnx4: write_super\n"));
77 	sb->s_dirt = 0;
78 	unlock_kernel();
79 }
80 
81 static int qnx4_write_inode(struct inode *inode, int unused)
82 {
83 	struct qnx4_inode_entry *raw_inode;
84 	int block, ino;
85 	struct buffer_head *bh;
86 	ino = inode->i_ino;
87 
88 	QNX4DEBUG(("qnx4: write inode 1.\n"));
89 	if (inode->i_nlink == 0) {
90 		return 0;
91 	}
92 	if (!ino) {
93 		printk("qnx4: bad inode number on dev %s: %d is out of range\n",
94 		       inode->i_sb->s_id, ino);
95 		return -EIO;
96 	}
97 	QNX4DEBUG(("qnx4: write inode 2.\n"));
98 	block = ino / QNX4_INODES_PER_BLOCK;
99 	lock_kernel();
100 	if (!(bh = sb_bread(inode->i_sb, block))) {
101 		printk("qnx4: major problem: unable to read inode from dev "
102 		       "%s\n", inode->i_sb->s_id);
103 		unlock_kernel();
104 		return -EIO;
105 	}
106 	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
107 	    (ino % QNX4_INODES_PER_BLOCK);
108 	raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
109 	raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
110 	raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
111 	raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
112 	raw_inode->di_size  = cpu_to_le32(inode->i_size);
113 	raw_inode->di_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
114 	raw_inode->di_atime = cpu_to_le32(inode->i_atime.tv_sec);
115 	raw_inode->di_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
116 	raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
117 	mark_buffer_dirty(bh);
118 	brelse(bh);
119 	unlock_kernel();
120 	return 0;
121 }
122 
123 #endif
124 
125 static void qnx4_put_super(struct super_block *sb);
126 static struct inode *qnx4_alloc_inode(struct super_block *sb);
127 static void qnx4_destroy_inode(struct inode *inode);
128 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
129 static int qnx4_statfs(struct dentry *, struct kstatfs *);
130 
131 static const struct super_operations qnx4_sops =
132 {
133 	.alloc_inode	= qnx4_alloc_inode,
134 	.destroy_inode	= qnx4_destroy_inode,
135 	.put_super	= qnx4_put_super,
136 	.statfs		= qnx4_statfs,
137 	.remount_fs	= qnx4_remount,
138 #ifdef CONFIG_QNX4FS_RW
139 	.write_inode	= qnx4_write_inode,
140 	.delete_inode	= qnx4_delete_inode,
141 	.write_super	= qnx4_write_super,
142 #endif
143 };
144 
145 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
146 {
147 	struct qnx4_sb_info *qs;
148 
149 	qs = qnx4_sb(sb);
150 	qs->Version = QNX4_VERSION;
151 #ifndef CONFIG_QNX4FS_RW
152 	*flags |= MS_RDONLY;
153 #endif
154 	if (*flags & MS_RDONLY) {
155 		return 0;
156 	}
157 
158 	mark_buffer_dirty(qs->sb_buf);
159 
160 	return 0;
161 }
162 
163 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
164 				       int create)
165 {
166 	struct buffer_head *result = NULL;
167 
168 	if ( nr >= 0 )
169 		nr = qnx4_block_map( inode, nr );
170 	if (nr) {
171 		result = sb_getblk(inode->i_sb, nr);
172 		return result;
173 	}
174 	if (!create) {
175 		return NULL;
176 	}
177 #if 0
178 	tmp = qnx4_new_block(inode->i_sb);
179 	if (!tmp) {
180 		return NULL;
181 	}
182 	result = sb_getblk(inode->i_sb, tmp);
183 	if (tst) {
184 		qnx4_free_block(inode->i_sb, tmp);
185 		brelse(result);
186 		goto repeat;
187 	}
188 	tst = tmp;
189 #endif
190 	inode->i_ctime = CURRENT_TIME_SEC;
191 	mark_inode_dirty(inode);
192 	return result;
193 }
194 
195 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
196 {
197 	struct buffer_head *bh;
198 
199 	bh = qnx4_getblk(inode, block, create);
200 	if (!bh || buffer_uptodate(bh)) {
201 		return bh;
202 	}
203 	ll_rw_block(READ, 1, &bh);
204 	wait_on_buffer(bh);
205 	if (buffer_uptodate(bh)) {
206 		return bh;
207 	}
208 	brelse(bh);
209 
210 	return NULL;
211 }
212 
213 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
214 {
215 	unsigned long phys;
216 
217 	QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
218 
219 	phys = qnx4_block_map( inode, iblock );
220 	if ( phys ) {
221 		// logical block is before EOF
222 		map_bh(bh, inode->i_sb, phys);
223 	} else if ( create ) {
224 		// to be done.
225 	}
226 	return 0;
227 }
228 
229 unsigned long qnx4_block_map( struct inode *inode, long iblock )
230 {
231 	int ix;
232 	long offset, i_xblk;
233 	unsigned long block = 0;
234 	struct buffer_head *bh = NULL;
235 	struct qnx4_xblk *xblk = NULL;
236 	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
237 	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
238 
239 	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
240 		// iblock is in the first extent. This is easy.
241 		block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
242 	} else {
243 		// iblock is beyond first extent. We have to follow the extent chain.
244 		i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
245 		offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
246 		ix = 0;
247 		while ( --nxtnt > 0 ) {
248 			if ( ix == 0 ) {
249 				// read next xtnt block.
250 				bh = sb_bread(inode->i_sb, i_xblk - 1);
251 				if ( !bh ) {
252 					QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
253 					return -EIO;
254 				}
255 				xblk = (struct qnx4_xblk*)bh->b_data;
256 				if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
257 					QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
258 					return -EIO;
259 				}
260 			}
261 			if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
262 				// got it!
263 				block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
264 				break;
265 			}
266 			offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
267 			if ( ++ix >= xblk->xblk_num_xtnts ) {
268 				i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
269 				ix = 0;
270 				brelse( bh );
271 				bh = NULL;
272 			}
273 		}
274 		if ( bh )
275 			brelse( bh );
276 	}
277 
278 	QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
279 	return block;
280 }
281 
282 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
283 {
284 	struct super_block *sb = dentry->d_sb;
285 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
286 
287 	lock_kernel();
288 
289 	buf->f_type    = sb->s_magic;
290 	buf->f_bsize   = sb->s_blocksize;
291 	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
292 	buf->f_bfree   = qnx4_count_free_blocks(sb);
293 	buf->f_bavail  = buf->f_bfree;
294 	buf->f_namelen = QNX4_NAME_MAX;
295 	buf->f_fsid.val[0] = (u32)id;
296 	buf->f_fsid.val[1] = (u32)(id >> 32);
297 
298 	unlock_kernel();
299 
300 	return 0;
301 }
302 
303 /*
304  * Check the root directory of the filesystem to make sure
305  * it really _is_ a qnx4 filesystem, and to check the size
306  * of the directory entry.
307  */
308 static const char *qnx4_checkroot(struct super_block *sb)
309 {
310 	struct buffer_head *bh;
311 	struct qnx4_inode_entry *rootdir;
312 	int rd, rl;
313 	int i, j;
314 	int found = 0;
315 
316 	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
317 		return "no qnx4 filesystem (no root dir).";
318 	} else {
319 		QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
320 		rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
321 		rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
322 		for (j = 0; j < rl; j++) {
323 			bh = sb_bread(sb, rd + j);	/* root dir, first block */
324 			if (bh == NULL) {
325 				return "unable to read root entry.";
326 			}
327 			for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
328 				rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
329 				if (rootdir->di_fname != NULL) {
330 					QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
331 					if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
332 						found = 1;
333 						qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
334 						if (!qnx4_sb(sb)->BitMap) {
335 							brelse (bh);
336 							return "not enough memory for bitmap inode";
337 						}
338 						memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );	/* keep bitmap inode known */
339 						break;
340 					}
341 				}
342 			}
343 			brelse(bh);
344 			if (found != 0) {
345 				break;
346 			}
347 		}
348 		if (found == 0) {
349 			return "bitmap file not found.";
350 		}
351 	}
352 	return NULL;
353 }
354 
355 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
356 {
357 	struct buffer_head *bh;
358 	struct inode *root;
359 	const char *errmsg;
360 	struct qnx4_sb_info *qs;
361 	int ret = -EINVAL;
362 
363 	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
364 	if (!qs)
365 		return -ENOMEM;
366 	s->s_fs_info = qs;
367 
368 	sb_set_blocksize(s, QNX4_BLOCK_SIZE);
369 
370 	/* Check the superblock signature. Since the qnx4 code is
371 	   dangerous, we should leave as quickly as possible
372 	   if we don't belong here... */
373 	bh = sb_bread(s, 1);
374 	if (!bh) {
375 		printk("qnx4: unable to read the superblock\n");
376 		goto outnobh;
377 	}
378 	if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
379 		if (!silent)
380 			printk("qnx4: wrong fsid in superblock.\n");
381 		goto out;
382 	}
383 	s->s_op = &qnx4_sops;
384 	s->s_magic = QNX4_SUPER_MAGIC;
385 #ifndef CONFIG_QNX4FS_RW
386 	s->s_flags |= MS_RDONLY;	/* Yup, read-only yet */
387 #endif
388 	qnx4_sb(s)->sb_buf = bh;
389 	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
390 
391 
392  	/* check before allocating dentries, inodes, .. */
393 	errmsg = qnx4_checkroot(s);
394 	if (errmsg != NULL) {
395  		if (!silent)
396  			printk("qnx4: %s\n", errmsg);
397 		goto out;
398 	}
399 
400  	/* does root not have inode number QNX4_ROOT_INO ?? */
401 	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
402 	if (IS_ERR(root)) {
403  		printk("qnx4: get inode failed\n");
404 		ret = PTR_ERR(root);
405  		goto out;
406  	}
407 
408 	ret = -ENOMEM;
409  	s->s_root = d_alloc_root(root);
410  	if (s->s_root == NULL)
411  		goto outi;
412 
413 	brelse(bh);
414 
415 	return 0;
416 
417       outi:
418 	iput(root);
419       out:
420 	brelse(bh);
421       outnobh:
422 	kfree(qs);
423 	s->s_fs_info = NULL;
424 	return ret;
425 }
426 
427 static void qnx4_put_super(struct super_block *sb)
428 {
429 	struct qnx4_sb_info *qs = qnx4_sb(sb);
430 	kfree( qs->BitMap );
431 	kfree( qs );
432 	sb->s_fs_info = NULL;
433 	return;
434 }
435 
436 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
437 {
438 	return block_write_full_page(page,qnx4_get_block, wbc);
439 }
440 
441 static int qnx4_readpage(struct file *file, struct page *page)
442 {
443 	return block_read_full_page(page,qnx4_get_block);
444 }
445 
446 static int qnx4_write_begin(struct file *file, struct address_space *mapping,
447 			loff_t pos, unsigned len, unsigned flags,
448 			struct page **pagep, void **fsdata)
449 {
450 	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
451 	*pagep = NULL;
452 	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
453 				qnx4_get_block,
454 				&qnx4_inode->mmu_private);
455 }
456 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
457 {
458 	return generic_block_bmap(mapping,block,qnx4_get_block);
459 }
460 static const struct address_space_operations qnx4_aops = {
461 	.readpage	= qnx4_readpage,
462 	.writepage	= qnx4_writepage,
463 	.sync_page	= block_sync_page,
464 	.write_begin	= qnx4_write_begin,
465 	.write_end	= generic_write_end,
466 	.bmap		= qnx4_bmap
467 };
468 
469 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
470 {
471 	struct buffer_head *bh;
472 	struct qnx4_inode_entry *raw_inode;
473 	int block;
474 	struct qnx4_inode_entry *qnx4_inode;
475 	struct inode *inode;
476 
477 	inode = iget_locked(sb, ino);
478 	if (!inode)
479 		return ERR_PTR(-ENOMEM);
480 	if (!(inode->i_state & I_NEW))
481 		return inode;
482 
483 	qnx4_inode = qnx4_raw_inode(inode);
484 	inode->i_mode = 0;
485 
486 	QNX4DEBUG(("Reading inode : [%d]\n", ino));
487 	if (!ino) {
488 		printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
489 				"out of range\n",
490 		       sb->s_id, ino);
491 		iget_failed(inode);
492 		return ERR_PTR(-EIO);
493 	}
494 	block = ino / QNX4_INODES_PER_BLOCK;
495 
496 	if (!(bh = sb_bread(sb, block))) {
497 		printk("qnx4: major problem: unable to read inode from dev "
498 		       "%s\n", sb->s_id);
499 		iget_failed(inode);
500 		return ERR_PTR(-EIO);
501 	}
502 	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
503 	    (ino % QNX4_INODES_PER_BLOCK);
504 
505 	inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
506 	inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
507 	inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
508 	inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
509 	inode->i_size    = le32_to_cpu(raw_inode->di_size);
510 	inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
511 	inode->i_mtime.tv_nsec = 0;
512 	inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
513 	inode->i_atime.tv_nsec = 0;
514 	inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
515 	inode->i_ctime.tv_nsec = 0;
516 	inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
517 
518 	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
519 	if (S_ISREG(inode->i_mode)) {
520 		inode->i_op = &qnx4_file_inode_operations;
521 		inode->i_fop = &qnx4_file_operations;
522 		inode->i_mapping->a_ops = &qnx4_aops;
523 		qnx4_i(inode)->mmu_private = inode->i_size;
524 	} else if (S_ISDIR(inode->i_mode)) {
525 		inode->i_op = &qnx4_dir_inode_operations;
526 		inode->i_fop = &qnx4_dir_operations;
527 	} else if (S_ISLNK(inode->i_mode)) {
528 		inode->i_op = &page_symlink_inode_operations;
529 		inode->i_mapping->a_ops = &qnx4_aops;
530 		qnx4_i(inode)->mmu_private = inode->i_size;
531 	} else {
532 		printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
533 			ino, sb->s_id);
534 		iget_failed(inode);
535 		brelse(bh);
536 		return ERR_PTR(-EIO);
537 	}
538 	brelse(bh);
539 	unlock_new_inode(inode);
540 	return inode;
541 }
542 
543 static struct kmem_cache *qnx4_inode_cachep;
544 
545 static struct inode *qnx4_alloc_inode(struct super_block *sb)
546 {
547 	struct qnx4_inode_info *ei;
548 	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
549 	if (!ei)
550 		return NULL;
551 	return &ei->vfs_inode;
552 }
553 
554 static void qnx4_destroy_inode(struct inode *inode)
555 {
556 	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
557 }
558 
559 static void init_once(void *foo)
560 {
561 	struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
562 
563 	inode_init_once(&ei->vfs_inode);
564 }
565 
566 static int init_inodecache(void)
567 {
568 	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
569 					     sizeof(struct qnx4_inode_info),
570 					     0, (SLAB_RECLAIM_ACCOUNT|
571 						SLAB_MEM_SPREAD),
572 					     init_once);
573 	if (qnx4_inode_cachep == NULL)
574 		return -ENOMEM;
575 	return 0;
576 }
577 
578 static void destroy_inodecache(void)
579 {
580 	kmem_cache_destroy(qnx4_inode_cachep);
581 }
582 
583 static int qnx4_get_sb(struct file_system_type *fs_type,
584 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
585 {
586 	return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super,
587 			   mnt);
588 }
589 
590 static struct file_system_type qnx4_fs_type = {
591 	.owner		= THIS_MODULE,
592 	.name		= "qnx4",
593 	.get_sb		= qnx4_get_sb,
594 	.kill_sb	= kill_block_super,
595 	.fs_flags	= FS_REQUIRES_DEV,
596 };
597 
598 static int __init init_qnx4_fs(void)
599 {
600 	int err;
601 
602 	err = init_inodecache();
603 	if (err)
604 		return err;
605 
606 	err = register_filesystem(&qnx4_fs_type);
607 	if (err) {
608 		destroy_inodecache();
609 		return err;
610 	}
611 
612 	printk("QNX4 filesystem 0.2.3 registered.\n");
613 	return 0;
614 }
615 
616 static void __exit exit_qnx4_fs(void)
617 {
618 	unregister_filesystem(&qnx4_fs_type);
619 	destroy_inodecache();
620 }
621 
622 module_init(init_qnx4_fs)
623 module_exit(exit_qnx4_fs)
624 MODULE_LICENSE("GPL");
625 
626