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/init.h>
17 #include <linux/slab.h>
18 #include <linux/highuid.h>
19 #include <linux/pagemap.h>
20 #include <linux/buffer_head.h>
21 #include <linux/writeback.h>
22 #include <linux/statfs.h>
23 #include "qnx4.h"
24
25 #define QNX4_VERSION 4
26 #define QNX4_BMNAME ".bitmap"
27
28 static const struct super_operations qnx4_sops;
29
30 static void qnx4_put_super(struct super_block *sb);
31 static struct inode *qnx4_alloc_inode(struct super_block *sb);
32 static void qnx4_destroy_inode(struct inode *inode);
33 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
34 static int qnx4_statfs(struct dentry *, struct kstatfs *);
35
36 static const struct super_operations qnx4_sops =
37 {
38 .alloc_inode = qnx4_alloc_inode,
39 .destroy_inode = qnx4_destroy_inode,
40 .put_super = qnx4_put_super,
41 .statfs = qnx4_statfs,
42 .remount_fs = qnx4_remount,
43 };
44
qnx4_remount(struct super_block * sb,int * flags,char * data)45 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
46 {
47 struct qnx4_sb_info *qs;
48
49 qs = qnx4_sb(sb);
50 qs->Version = QNX4_VERSION;
51 *flags |= MS_RDONLY;
52 return 0;
53 }
54
qnx4_getblk(struct inode * inode,int nr,int create)55 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
56 int create)
57 {
58 struct buffer_head *result = NULL;
59
60 if ( nr >= 0 )
61 nr = qnx4_block_map( inode, nr );
62 if (nr) {
63 result = sb_getblk(inode->i_sb, nr);
64 return result;
65 }
66 return NULL;
67 }
68
qnx4_bread(struct inode * inode,int block,int create)69 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
70 {
71 struct buffer_head *bh;
72
73 bh = qnx4_getblk(inode, block, create);
74 if (!bh || buffer_uptodate(bh)) {
75 return bh;
76 }
77 ll_rw_block(READ, 1, &bh);
78 wait_on_buffer(bh);
79 if (buffer_uptodate(bh)) {
80 return bh;
81 }
82 brelse(bh);
83
84 return NULL;
85 }
86
qnx4_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh,int create)87 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
88 {
89 unsigned long phys;
90
91 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
92
93 phys = qnx4_block_map( inode, iblock );
94 if ( phys ) {
95 // logical block is before EOF
96 map_bh(bh, inode->i_sb, phys);
97 }
98 return 0;
99 }
100
qnx4_block_map(struct inode * inode,long iblock)101 unsigned long qnx4_block_map( struct inode *inode, long iblock )
102 {
103 int ix;
104 long offset, i_xblk;
105 unsigned long block = 0;
106 struct buffer_head *bh = NULL;
107 struct qnx4_xblk *xblk = NULL;
108 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
109 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
110
111 if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
112 // iblock is in the first extent. This is easy.
113 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
114 } else {
115 // iblock is beyond first extent. We have to follow the extent chain.
116 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
117 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
118 ix = 0;
119 while ( --nxtnt > 0 ) {
120 if ( ix == 0 ) {
121 // read next xtnt block.
122 bh = sb_bread(inode->i_sb, i_xblk - 1);
123 if ( !bh ) {
124 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
125 return -EIO;
126 }
127 xblk = (struct qnx4_xblk*)bh->b_data;
128 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
129 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
130 return -EIO;
131 }
132 }
133 if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
134 // got it!
135 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
136 break;
137 }
138 offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
139 if ( ++ix >= xblk->xblk_num_xtnts ) {
140 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
141 ix = 0;
142 brelse( bh );
143 bh = NULL;
144 }
145 }
146 if ( bh )
147 brelse( bh );
148 }
149
150 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
151 return block;
152 }
153
qnx4_statfs(struct dentry * dentry,struct kstatfs * buf)154 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
155 {
156 struct super_block *sb = dentry->d_sb;
157 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
158
159 buf->f_type = sb->s_magic;
160 buf->f_bsize = sb->s_blocksize;
161 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
162 buf->f_bfree = qnx4_count_free_blocks(sb);
163 buf->f_bavail = buf->f_bfree;
164 buf->f_namelen = QNX4_NAME_MAX;
165 buf->f_fsid.val[0] = (u32)id;
166 buf->f_fsid.val[1] = (u32)(id >> 32);
167
168 return 0;
169 }
170
171 /*
172 * Check the root directory of the filesystem to make sure
173 * it really _is_ a qnx4 filesystem, and to check the size
174 * of the directory entry.
175 */
qnx4_checkroot(struct super_block * sb)176 static const char *qnx4_checkroot(struct super_block *sb)
177 {
178 struct buffer_head *bh;
179 struct qnx4_inode_entry *rootdir;
180 int rd, rl;
181 int i, j;
182 int found = 0;
183
184 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
185 return "no qnx4 filesystem (no root dir).";
186 } else {
187 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
188 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
189 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
190 for (j = 0; j < rl; j++) {
191 bh = sb_bread(sb, rd + j); /* root dir, first block */
192 if (bh == NULL) {
193 return "unable to read root entry.";
194 }
195 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
196 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
197 if (rootdir->di_fname != NULL) {
198 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
199 if (!strcmp(rootdir->di_fname,
200 QNX4_BMNAME)) {
201 found = 1;
202 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
203 if (!qnx4_sb(sb)->BitMap) {
204 brelse (bh);
205 return "not enough memory for bitmap inode";
206 }
207 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */
208 break;
209 }
210 }
211 }
212 brelse(bh);
213 if (found != 0) {
214 break;
215 }
216 }
217 if (found == 0) {
218 return "bitmap file not found.";
219 }
220 }
221 return NULL;
222 }
223
qnx4_fill_super(struct super_block * s,void * data,int silent)224 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
225 {
226 struct buffer_head *bh;
227 struct inode *root;
228 const char *errmsg;
229 struct qnx4_sb_info *qs;
230 int ret = -EINVAL;
231
232 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
233 if (!qs)
234 return -ENOMEM;
235 s->s_fs_info = qs;
236
237 sb_set_blocksize(s, QNX4_BLOCK_SIZE);
238
239 /* Check the superblock signature. Since the qnx4 code is
240 dangerous, we should leave as quickly as possible
241 if we don't belong here... */
242 bh = sb_bread(s, 1);
243 if (!bh) {
244 printk(KERN_ERR "qnx4: unable to read the superblock\n");
245 goto outnobh;
246 }
247 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
248 if (!silent)
249 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
250 goto out;
251 }
252 s->s_op = &qnx4_sops;
253 s->s_magic = QNX4_SUPER_MAGIC;
254 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
255 qnx4_sb(s)->sb_buf = bh;
256 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
257
258
259 /* check before allocating dentries, inodes, .. */
260 errmsg = qnx4_checkroot(s);
261 if (errmsg != NULL) {
262 if (!silent)
263 printk(KERN_ERR "qnx4: %s\n", errmsg);
264 goto out;
265 }
266
267 /* does root not have inode number QNX4_ROOT_INO ?? */
268 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
269 if (IS_ERR(root)) {
270 printk(KERN_ERR "qnx4: get inode failed\n");
271 ret = PTR_ERR(root);
272 goto out;
273 }
274
275 ret = -ENOMEM;
276 s->s_root = d_alloc_root(root);
277 if (s->s_root == NULL)
278 goto outi;
279
280 brelse(bh);
281 return 0;
282
283 outi:
284 iput(root);
285 out:
286 brelse(bh);
287 outnobh:
288 kfree(qs);
289 s->s_fs_info = NULL;
290 return ret;
291 }
292
qnx4_put_super(struct super_block * sb)293 static void qnx4_put_super(struct super_block *sb)
294 {
295 struct qnx4_sb_info *qs = qnx4_sb(sb);
296 kfree( qs->BitMap );
297 kfree( qs );
298 sb->s_fs_info = NULL;
299 return;
300 }
301
qnx4_writepage(struct page * page,struct writeback_control * wbc)302 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
303 {
304 return block_write_full_page(page,qnx4_get_block, wbc);
305 }
306
qnx4_readpage(struct file * file,struct page * page)307 static int qnx4_readpage(struct file *file, struct page *page)
308 {
309 return block_read_full_page(page,qnx4_get_block);
310 }
311
qnx4_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)312 static int qnx4_write_begin(struct file *file, struct address_space *mapping,
313 loff_t pos, unsigned len, unsigned flags,
314 struct page **pagep, void **fsdata)
315 {
316 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
317 int ret;
318
319 *pagep = NULL;
320 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
321 qnx4_get_block,
322 &qnx4_inode->mmu_private);
323 if (unlikely(ret)) {
324 loff_t isize = mapping->host->i_size;
325 if (pos + len > isize)
326 vmtruncate(mapping->host, isize);
327 }
328
329 return ret;
330 }
qnx4_bmap(struct address_space * mapping,sector_t block)331 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
332 {
333 return generic_block_bmap(mapping,block,qnx4_get_block);
334 }
335 static const struct address_space_operations qnx4_aops = {
336 .readpage = qnx4_readpage,
337 .writepage = qnx4_writepage,
338 .write_begin = qnx4_write_begin,
339 .write_end = generic_write_end,
340 .bmap = qnx4_bmap
341 };
342
qnx4_iget(struct super_block * sb,unsigned long ino)343 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
344 {
345 struct buffer_head *bh;
346 struct qnx4_inode_entry *raw_inode;
347 int block;
348 struct qnx4_inode_entry *qnx4_inode;
349 struct inode *inode;
350
351 inode = iget_locked(sb, ino);
352 if (!inode)
353 return ERR_PTR(-ENOMEM);
354 if (!(inode->i_state & I_NEW))
355 return inode;
356
357 qnx4_inode = qnx4_raw_inode(inode);
358 inode->i_mode = 0;
359
360 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
361 if (!ino) {
362 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
363 "out of range\n",
364 sb->s_id, ino);
365 iget_failed(inode);
366 return ERR_PTR(-EIO);
367 }
368 block = ino / QNX4_INODES_PER_BLOCK;
369
370 if (!(bh = sb_bread(sb, block))) {
371 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
372 "%s\n", sb->s_id);
373 iget_failed(inode);
374 return ERR_PTR(-EIO);
375 }
376 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
377 (ino % QNX4_INODES_PER_BLOCK);
378
379 inode->i_mode = le16_to_cpu(raw_inode->di_mode);
380 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid);
381 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid);
382 inode->i_nlink = le16_to_cpu(raw_inode->di_nlink);
383 inode->i_size = le32_to_cpu(raw_inode->di_size);
384 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
385 inode->i_mtime.tv_nsec = 0;
386 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
387 inode->i_atime.tv_nsec = 0;
388 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
389 inode->i_ctime.tv_nsec = 0;
390 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
391
392 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
393 if (S_ISREG(inode->i_mode)) {
394 inode->i_fop = &generic_ro_fops;
395 inode->i_mapping->a_ops = &qnx4_aops;
396 qnx4_i(inode)->mmu_private = inode->i_size;
397 } else if (S_ISDIR(inode->i_mode)) {
398 inode->i_op = &qnx4_dir_inode_operations;
399 inode->i_fop = &qnx4_dir_operations;
400 } else if (S_ISLNK(inode->i_mode)) {
401 inode->i_op = &page_symlink_inode_operations;
402 inode->i_mapping->a_ops = &qnx4_aops;
403 qnx4_i(inode)->mmu_private = inode->i_size;
404 } else {
405 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
406 ino, sb->s_id);
407 iget_failed(inode);
408 brelse(bh);
409 return ERR_PTR(-EIO);
410 }
411 brelse(bh);
412 unlock_new_inode(inode);
413 return inode;
414 }
415
416 static struct kmem_cache *qnx4_inode_cachep;
417
qnx4_alloc_inode(struct super_block * sb)418 static struct inode *qnx4_alloc_inode(struct super_block *sb)
419 {
420 struct qnx4_inode_info *ei;
421 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
422 if (!ei)
423 return NULL;
424 return &ei->vfs_inode;
425 }
426
qnx4_i_callback(struct rcu_head * head)427 static void qnx4_i_callback(struct rcu_head *head)
428 {
429 struct inode *inode = container_of(head, struct inode, i_rcu);
430 INIT_LIST_HEAD(&inode->i_dentry);
431 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
432 }
433
qnx4_destroy_inode(struct inode * inode)434 static void qnx4_destroy_inode(struct inode *inode)
435 {
436 call_rcu(&inode->i_rcu, qnx4_i_callback);
437 }
438
init_once(void * foo)439 static void init_once(void *foo)
440 {
441 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
442
443 inode_init_once(&ei->vfs_inode);
444 }
445
init_inodecache(void)446 static int init_inodecache(void)
447 {
448 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
449 sizeof(struct qnx4_inode_info),
450 0, (SLAB_RECLAIM_ACCOUNT|
451 SLAB_MEM_SPREAD),
452 init_once);
453 if (qnx4_inode_cachep == NULL)
454 return -ENOMEM;
455 return 0;
456 }
457
destroy_inodecache(void)458 static void destroy_inodecache(void)
459 {
460 kmem_cache_destroy(qnx4_inode_cachep);
461 }
462
qnx4_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)463 static struct dentry *qnx4_mount(struct file_system_type *fs_type,
464 int flags, const char *dev_name, void *data)
465 {
466 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
467 }
468
469 static struct file_system_type qnx4_fs_type = {
470 .owner = THIS_MODULE,
471 .name = "qnx4",
472 .mount = qnx4_mount,
473 .kill_sb = kill_block_super,
474 .fs_flags = FS_REQUIRES_DEV,
475 };
476
init_qnx4_fs(void)477 static int __init init_qnx4_fs(void)
478 {
479 int err;
480
481 err = init_inodecache();
482 if (err)
483 return err;
484
485 err = register_filesystem(&qnx4_fs_type);
486 if (err) {
487 destroy_inodecache();
488 return err;
489 }
490
491 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
492 return 0;
493 }
494
exit_qnx4_fs(void)495 static void __exit exit_qnx4_fs(void)
496 {
497 unregister_filesystem(&qnx4_fs_type);
498 destroy_inodecache();
499 }
500
501 module_init(init_qnx4_fs)
502 module_exit(exit_qnx4_fs)
503 MODULE_LICENSE("GPL");
504
505