Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
/*
 * QNX4 file system, Linux implementation.
 *
 * Version : 0.2.1
 *
 * Using parts of the xiafs filesystem.
 *
 * History :
 *
 * 01-06-1998 by Richard Frowijn : first release.
 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
 * 30-06-1998 by Frank Denis : first step to write inodes.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/highuid.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include "qnx4.h"

#define QNX4_VERSION  4
#define QNX4_BMNAME   ".bitmap"

static const struct super_operations qnx4_sops;

static void qnx4_put_super(struct super_block *sb);
static struct inode *qnx4_alloc_inode(struct super_block *sb);
static void qnx4_destroy_inode(struct inode *inode);
static int qnx4_remount(struct super_block *sb, int *flags, char *data);
static int qnx4_statfs(struct dentry *, struct kstatfs *);

static const struct super_operations qnx4_sops =
{
	.alloc_inode	= qnx4_alloc_inode,
	.destroy_inode	= qnx4_destroy_inode,
	.put_super	= qnx4_put_super,
	.statfs		= qnx4_statfs,
	.remount_fs	= qnx4_remount,
};

static int qnx4_remount(struct super_block *sb, int *flags, char *data)
{
	struct qnx4_sb_info *qs;

	qs = qnx4_sb(sb);
	qs->Version = QNX4_VERSION;
	*flags |= MS_RDONLY;
	return 0;
}

static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
				       int create)
{
	struct buffer_head *result = NULL;

	if ( nr >= 0 )
		nr = qnx4_block_map( inode, nr );
	if (nr) {
		result = sb_getblk(inode->i_sb, nr);
		return result;
	}
	return NULL;
}

struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
{
	struct buffer_head *bh;

	bh = qnx4_getblk(inode, block, create);
	if (!bh || buffer_uptodate(bh)) {
		return bh;
	}
	ll_rw_block(READ, 1, &bh);
	wait_on_buffer(bh);
	if (buffer_uptodate(bh)) {
		return bh;
	}
	brelse(bh);

	return NULL;
}

static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
{
	unsigned long phys;

	QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));

	phys = qnx4_block_map( inode, iblock );
	if ( phys ) {
		// logical block is before EOF
		map_bh(bh, inode->i_sb, phys);
	}
	return 0;
}

unsigned long qnx4_block_map( struct inode *inode, long iblock )
{
	int ix;
	long offset, i_xblk;
	unsigned long block = 0;
	struct buffer_head *bh = NULL;
	struct qnx4_xblk *xblk = NULL;
	struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
	u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);

	if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
		// iblock is in the first extent. This is easy.
		block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
	} else {
		// iblock is beyond first extent. We have to follow the extent chain.
		i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
		offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
		ix = 0;
		while ( --nxtnt > 0 ) {
			if ( ix == 0 ) {
				// read next xtnt block.
				bh = sb_bread(inode->i_sb, i_xblk - 1);
				if ( !bh ) {
					QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
					return -EIO;
				}
				xblk = (struct qnx4_xblk*)bh->b_data;
				if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
					QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
					return -EIO;
				}
			}
			if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
				// got it!
				block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
				break;
			}
			offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
			if ( ++ix >= xblk->xblk_num_xtnts ) {
				i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
				ix = 0;
				brelse( bh );
				bh = NULL;
			}
		}
		if ( bh )
			brelse( bh );
	}

	QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
	return block;
}

static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);

	lock_kernel();

	buf->f_type    = sb->s_magic;
	buf->f_bsize   = sb->s_blocksize;
	buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
	buf->f_bfree   = qnx4_count_free_blocks(sb);
	buf->f_bavail  = buf->f_bfree;
	buf->f_namelen = QNX4_NAME_MAX;
	buf->f_fsid.val[0] = (u32)id;
	buf->f_fsid.val[1] = (u32)(id >> 32);

	unlock_kernel();

	return 0;
}

/*
 * Check the root directory of the filesystem to make sure
 * it really _is_ a qnx4 filesystem, and to check the size
 * of the directory entry.
 */
static const char *qnx4_checkroot(struct super_block *sb)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *rootdir;
	int rd, rl;
	int i, j;
	int found = 0;

	if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
		return "no qnx4 filesystem (no root dir).";
	} else {
		QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
		rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
		rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
		for (j = 0; j < rl; j++) {
			bh = sb_bread(sb, rd + j);	/* root dir, first block */
			if (bh == NULL) {
				return "unable to read root entry.";
			}
			for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
				rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
				if (rootdir->di_fname != NULL) {
					QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
					if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
						found = 1;
						qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
						if (!qnx4_sb(sb)->BitMap) {
							brelse (bh);
							return "not enough memory for bitmap inode";
						}
						memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );	/* keep bitmap inode known */
						break;
					}
				}
			}
			brelse(bh);
			if (found != 0) {
				break;
			}
		}
		if (found == 0) {
			return "bitmap file not found.";
		}
	}
	return NULL;
}

static int qnx4_fill_super(struct super_block *s, void *data, int silent)
{
	struct buffer_head *bh;
	struct inode *root;
	const char *errmsg;
	struct qnx4_sb_info *qs;
	int ret = -EINVAL;

	qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
	if (!qs)
		return -ENOMEM;
	s->s_fs_info = qs;

	sb_set_blocksize(s, QNX4_BLOCK_SIZE);

	/* Check the superblock signature. Since the qnx4 code is
	   dangerous, we should leave as quickly as possible
	   if we don't belong here... */
	bh = sb_bread(s, 1);
	if (!bh) {
		printk(KERN_ERR "qnx4: unable to read the superblock\n");
		goto outnobh;
	}
	if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
		if (!silent)
			printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
		goto out;
	}
	s->s_op = &qnx4_sops;
	s->s_magic = QNX4_SUPER_MAGIC;
	s->s_flags |= MS_RDONLY;	/* Yup, read-only yet */
	qnx4_sb(s)->sb_buf = bh;
	qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;


 	/* check before allocating dentries, inodes, .. */
	errmsg = qnx4_checkroot(s);
	if (errmsg != NULL) {
 		if (!silent)
			printk(KERN_ERR "qnx4: %s\n", errmsg);
		goto out;
	}

 	/* does root not have inode number QNX4_ROOT_INO ?? */
	root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
	if (IS_ERR(root)) {
		printk(KERN_ERR "qnx4: get inode failed\n");
		ret = PTR_ERR(root);
 		goto out;
 	}

	ret = -ENOMEM;
 	s->s_root = d_alloc_root(root);
 	if (s->s_root == NULL)
 		goto outi;

	brelse(bh);

	return 0;

      outi:
	iput(root);
      out:
	brelse(bh);
      outnobh:
	kfree(qs);
	s->s_fs_info = NULL;
	return ret;
}

static void qnx4_put_super(struct super_block *sb)
{
	struct qnx4_sb_info *qs = qnx4_sb(sb);
	kfree( qs->BitMap );
	kfree( qs );
	sb->s_fs_info = NULL;
	return;
}

static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page,qnx4_get_block, wbc);
}

static int qnx4_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page,qnx4_get_block);
}

static int qnx4_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
	*pagep = NULL;
	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				qnx4_get_block,
				&qnx4_inode->mmu_private);
}
static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping,block,qnx4_get_block);
}
static const struct address_space_operations qnx4_aops = {
	.readpage	= qnx4_readpage,
	.writepage	= qnx4_writepage,
	.sync_page	= block_sync_page,
	.write_begin	= qnx4_write_begin,
	.write_end	= generic_write_end,
	.bmap		= qnx4_bmap
};

struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *raw_inode;
	int block;
	struct qnx4_inode_entry *qnx4_inode;
	struct inode *inode;

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	qnx4_inode = qnx4_raw_inode(inode);
	inode->i_mode = 0;

	QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
	if (!ino) {
		printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
				"out of range\n",
		       sb->s_id, ino);
		iget_failed(inode);
		return ERR_PTR(-EIO);
	}
	block = ino / QNX4_INODES_PER_BLOCK;

	if (!(bh = sb_bread(sb, block))) {
		printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
		       "%s\n", sb->s_id);
		iget_failed(inode);
		return ERR_PTR(-EIO);
	}
	raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
	    (ino % QNX4_INODES_PER_BLOCK);

	inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
	inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
	inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
	inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
	inode->i_size    = le32_to_cpu(raw_inode->di_size);
	inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
	inode->i_mtime.tv_nsec = 0;
	inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
	inode->i_atime.tv_nsec = 0;
	inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
	inode->i_ctime.tv_nsec = 0;
	inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);

	memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
	if (S_ISREG(inode->i_mode)) {
		inode->i_fop = &generic_ro_fops;
		inode->i_mapping->a_ops = &qnx4_aops;
		qnx4_i(inode)->mmu_private = inode->i_size;
	} else if (S_ISDIR(inode->i_mode)) {
		inode->i_op = &qnx4_dir_inode_operations;
		inode->i_fop = &qnx4_dir_operations;
	} else if (S_ISLNK(inode->i_mode)) {
		inode->i_op = &page_symlink_inode_operations;
		inode->i_mapping->a_ops = &qnx4_aops;
		qnx4_i(inode)->mmu_private = inode->i_size;
	} else {
		printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
			ino, sb->s_id);
		iget_failed(inode);
		brelse(bh);
		return ERR_PTR(-EIO);
	}
	brelse(bh);
	unlock_new_inode(inode);
	return inode;
}

static struct kmem_cache *qnx4_inode_cachep;

static struct inode *qnx4_alloc_inode(struct super_block *sb)
{
	struct qnx4_inode_info *ei;
	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	return &ei->vfs_inode;
}

static void qnx4_destroy_inode(struct inode *inode)
{
	kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}

static void init_once(void *foo)
{
	struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;

	inode_init_once(&ei->vfs_inode);
}

static int init_inodecache(void)
{
	qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
					     sizeof(struct qnx4_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once);
	if (qnx4_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	kmem_cache_destroy(qnx4_inode_cachep);
}

static int qnx4_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super,
			   mnt);
}

static struct file_system_type qnx4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "qnx4",
	.get_sb		= qnx4_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static int __init init_qnx4_fs(void)
{
	int err;

	err = init_inodecache();
	if (err)
		return err;

	err = register_filesystem(&qnx4_fs_type);
	if (err) {
		destroy_inodecache();
		return err;
	}

	printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
	return 0;
}

static void __exit exit_qnx4_fs(void)
{
	unregister_filesystem(&qnx4_fs_type);
	destroy_inodecache();
}

module_init(init_qnx4_fs)
module_exit(exit_qnx4_fs)
MODULE_LICENSE("GPL");