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
183 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/')
184 return "no qnx4 filesystem (no root dir).";
185 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
186 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
187 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
188 for (j = 0; j < rl; j++) {
189 bh = sb_bread(sb, rd + j); /* root dir, first block */
190 if (bh == NULL)
191 return "unable to read root entry.";
192 rootdir = (struct qnx4_inode_entry *) bh->b_data;
193 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
194 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
195 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
196 continue;
197 qnx4_sb(sb)->BitMap = kmemdup(rootdir,
198 sizeof(struct qnx4_inode_entry),
199 GFP_KERNEL);
200 brelse(bh);
201 if (!qnx4_sb(sb)->BitMap)
202 return "not enough memory for bitmap inode";
203 /* keep bitmap inode known */
204 return NULL;
205 }
206 brelse(bh);
207 }
208 return "bitmap file not found.";
209 }
210
qnx4_fill_super(struct super_block * s,void * data,int silent)211 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
212 {
213 struct buffer_head *bh;
214 struct inode *root;
215 const char *errmsg;
216 struct qnx4_sb_info *qs;
217 int ret = -EINVAL;
218
219 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
220 if (!qs)
221 return -ENOMEM;
222 s->s_fs_info = qs;
223
224 sb_set_blocksize(s, QNX4_BLOCK_SIZE);
225
226 /* Check the superblock signature. Since the qnx4 code is
227 dangerous, we should leave as quickly as possible
228 if we don't belong here... */
229 bh = sb_bread(s, 1);
230 if (!bh) {
231 printk(KERN_ERR "qnx4: unable to read the superblock\n");
232 goto outnobh;
233 }
234 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
235 if (!silent)
236 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
237 goto out;
238 }
239 s->s_op = &qnx4_sops;
240 s->s_magic = QNX4_SUPER_MAGIC;
241 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
242 qnx4_sb(s)->sb_buf = bh;
243 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
244
245
246 /* check before allocating dentries, inodes, .. */
247 errmsg = qnx4_checkroot(s);
248 if (errmsg != NULL) {
249 if (!silent)
250 printk(KERN_ERR "qnx4: %s\n", errmsg);
251 goto out;
252 }
253
254 /* does root not have inode number QNX4_ROOT_INO ?? */
255 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
256 if (IS_ERR(root)) {
257 printk(KERN_ERR "qnx4: get inode failed\n");
258 ret = PTR_ERR(root);
259 goto outb;
260 }
261
262 ret = -ENOMEM;
263 s->s_root = d_alloc_root(root);
264 if (s->s_root == NULL)
265 goto outi;
266
267 brelse(bh);
268 return 0;
269
270 outi:
271 iput(root);
272 outb:
273 kfree(qs->BitMap);
274 out:
275 brelse(bh);
276 outnobh:
277 kfree(qs);
278 s->s_fs_info = NULL;
279 return ret;
280 }
281
qnx4_put_super(struct super_block * sb)282 static void qnx4_put_super(struct super_block *sb)
283 {
284 struct qnx4_sb_info *qs = qnx4_sb(sb);
285 kfree( qs->BitMap );
286 kfree( qs );
287 sb->s_fs_info = NULL;
288 return;
289 }
290
qnx4_writepage(struct page * page,struct writeback_control * wbc)291 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
292 {
293 return block_write_full_page(page,qnx4_get_block, wbc);
294 }
295
qnx4_readpage(struct file * file,struct page * page)296 static int qnx4_readpage(struct file *file, struct page *page)
297 {
298 return block_read_full_page(page,qnx4_get_block);
299 }
300
qnx4_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)301 static int qnx4_write_begin(struct file *file, struct address_space *mapping,
302 loff_t pos, unsigned len, unsigned flags,
303 struct page **pagep, void **fsdata)
304 {
305 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
306 int ret;
307
308 *pagep = NULL;
309 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
310 qnx4_get_block,
311 &qnx4_inode->mmu_private);
312 if (unlikely(ret)) {
313 loff_t isize = mapping->host->i_size;
314 if (pos + len > isize)
315 vmtruncate(mapping->host, isize);
316 }
317
318 return ret;
319 }
qnx4_bmap(struct address_space * mapping,sector_t block)320 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
321 {
322 return generic_block_bmap(mapping,block,qnx4_get_block);
323 }
324 static const struct address_space_operations qnx4_aops = {
325 .readpage = qnx4_readpage,
326 .writepage = qnx4_writepage,
327 .write_begin = qnx4_write_begin,
328 .write_end = generic_write_end,
329 .bmap = qnx4_bmap
330 };
331
qnx4_iget(struct super_block * sb,unsigned long ino)332 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
333 {
334 struct buffer_head *bh;
335 struct qnx4_inode_entry *raw_inode;
336 int block;
337 struct qnx4_inode_entry *qnx4_inode;
338 struct inode *inode;
339
340 inode = iget_locked(sb, ino);
341 if (!inode)
342 return ERR_PTR(-ENOMEM);
343 if (!(inode->i_state & I_NEW))
344 return inode;
345
346 qnx4_inode = qnx4_raw_inode(inode);
347 inode->i_mode = 0;
348
349 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
350 if (!ino) {
351 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
352 "out of range\n",
353 sb->s_id, ino);
354 iget_failed(inode);
355 return ERR_PTR(-EIO);
356 }
357 block = ino / QNX4_INODES_PER_BLOCK;
358
359 if (!(bh = sb_bread(sb, block))) {
360 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
361 "%s\n", sb->s_id);
362 iget_failed(inode);
363 return ERR_PTR(-EIO);
364 }
365 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
366 (ino % QNX4_INODES_PER_BLOCK);
367
368 inode->i_mode = le16_to_cpu(raw_inode->di_mode);
369 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid);
370 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid);
371 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
372 inode->i_size = le32_to_cpu(raw_inode->di_size);
373 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
374 inode->i_mtime.tv_nsec = 0;
375 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
376 inode->i_atime.tv_nsec = 0;
377 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
378 inode->i_ctime.tv_nsec = 0;
379 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
380
381 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
382 if (S_ISREG(inode->i_mode)) {
383 inode->i_fop = &generic_ro_fops;
384 inode->i_mapping->a_ops = &qnx4_aops;
385 qnx4_i(inode)->mmu_private = inode->i_size;
386 } else if (S_ISDIR(inode->i_mode)) {
387 inode->i_op = &qnx4_dir_inode_operations;
388 inode->i_fop = &qnx4_dir_operations;
389 } else if (S_ISLNK(inode->i_mode)) {
390 inode->i_op = &page_symlink_inode_operations;
391 inode->i_mapping->a_ops = &qnx4_aops;
392 qnx4_i(inode)->mmu_private = inode->i_size;
393 } else {
394 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
395 ino, sb->s_id);
396 iget_failed(inode);
397 brelse(bh);
398 return ERR_PTR(-EIO);
399 }
400 brelse(bh);
401 unlock_new_inode(inode);
402 return inode;
403 }
404
405 static struct kmem_cache *qnx4_inode_cachep;
406
qnx4_alloc_inode(struct super_block * sb)407 static struct inode *qnx4_alloc_inode(struct super_block *sb)
408 {
409 struct qnx4_inode_info *ei;
410 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
411 if (!ei)
412 return NULL;
413 return &ei->vfs_inode;
414 }
415
qnx4_i_callback(struct rcu_head * head)416 static void qnx4_i_callback(struct rcu_head *head)
417 {
418 struct inode *inode = container_of(head, struct inode, i_rcu);
419 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
420 }
421
qnx4_destroy_inode(struct inode * inode)422 static void qnx4_destroy_inode(struct inode *inode)
423 {
424 call_rcu(&inode->i_rcu, qnx4_i_callback);
425 }
426
init_once(void * foo)427 static void init_once(void *foo)
428 {
429 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
430
431 inode_init_once(&ei->vfs_inode);
432 }
433
init_inodecache(void)434 static int init_inodecache(void)
435 {
436 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
437 sizeof(struct qnx4_inode_info),
438 0, (SLAB_RECLAIM_ACCOUNT|
439 SLAB_MEM_SPREAD),
440 init_once);
441 if (qnx4_inode_cachep == NULL)
442 return -ENOMEM;
443 return 0;
444 }
445
destroy_inodecache(void)446 static void destroy_inodecache(void)
447 {
448 kmem_cache_destroy(qnx4_inode_cachep);
449 }
450
qnx4_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)451 static struct dentry *qnx4_mount(struct file_system_type *fs_type,
452 int flags, const char *dev_name, void *data)
453 {
454 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
455 }
456
457 static struct file_system_type qnx4_fs_type = {
458 .owner = THIS_MODULE,
459 .name = "qnx4",
460 .mount = qnx4_mount,
461 .kill_sb = kill_block_super,
462 .fs_flags = FS_REQUIRES_DEV,
463 };
464
init_qnx4_fs(void)465 static int __init init_qnx4_fs(void)
466 {
467 int err;
468
469 err = init_inodecache();
470 if (err)
471 return err;
472
473 err = register_filesystem(&qnx4_fs_type);
474 if (err) {
475 destroy_inodecache();
476 return err;
477 }
478
479 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
480 return 0;
481 }
482
exit_qnx4_fs(void)483 static void __exit exit_qnx4_fs(void)
484 {
485 unregister_filesystem(&qnx4_fs_type);
486 destroy_inodecache();
487 }
488
489 module_init(init_qnx4_fs)
490 module_exit(exit_qnx4_fs)
491 MODULE_LICENSE("GPL");
492
493