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_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh,int create)55 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
56 {
57 unsigned long phys;
58
59 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
60
61 phys = qnx4_block_map( inode, iblock );
62 if ( phys ) {
63 // logical block is before EOF
64 map_bh(bh, inode->i_sb, phys);
65 }
66 return 0;
67 }
68
try_extent(qnx4_xtnt_t * extent,u32 * offset)69 static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset)
70 {
71 u32 size = le32_to_cpu(extent->xtnt_size);
72 if (*offset < size)
73 return le32_to_cpu(extent->xtnt_blk) + *offset - 1;
74 *offset -= size;
75 return 0;
76 }
77
qnx4_block_map(struct inode * inode,long iblock)78 unsigned long qnx4_block_map( struct inode *inode, long iblock )
79 {
80 int ix;
81 long i_xblk;
82 struct buffer_head *bh = NULL;
83 struct qnx4_xblk *xblk = NULL;
84 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
85 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
86 u32 offset = iblock;
87 u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);
88
89 if (block) {
90 // iblock is in the first extent. This is easy.
91 } else {
92 // iblock is beyond first extent. We have to follow the extent chain.
93 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
94 ix = 0;
95 while ( --nxtnt > 0 ) {
96 if ( ix == 0 ) {
97 // read next xtnt block.
98 bh = sb_bread(inode->i_sb, i_xblk - 1);
99 if ( !bh ) {
100 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
101 return -EIO;
102 }
103 xblk = (struct qnx4_xblk*)bh->b_data;
104 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
105 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
106 return -EIO;
107 }
108 }
109 block = try_extent(&xblk->xblk_xtnts[ix], &offset);
110 if (block) {
111 // got it!
112 break;
113 }
114 if ( ++ix >= xblk->xblk_num_xtnts ) {
115 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
116 ix = 0;
117 brelse( bh );
118 bh = NULL;
119 }
120 }
121 if ( bh )
122 brelse( bh );
123 }
124
125 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
126 return block;
127 }
128
qnx4_statfs(struct dentry * dentry,struct kstatfs * buf)129 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
130 {
131 struct super_block *sb = dentry->d_sb;
132 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
133
134 buf->f_type = sb->s_magic;
135 buf->f_bsize = sb->s_blocksize;
136 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
137 buf->f_bfree = qnx4_count_free_blocks(sb);
138 buf->f_bavail = buf->f_bfree;
139 buf->f_namelen = QNX4_NAME_MAX;
140 buf->f_fsid.val[0] = (u32)id;
141 buf->f_fsid.val[1] = (u32)(id >> 32);
142
143 return 0;
144 }
145
146 /*
147 * Check the root directory of the filesystem to make sure
148 * it really _is_ a qnx4 filesystem, and to check the size
149 * of the directory entry.
150 */
qnx4_checkroot(struct super_block * sb)151 static const char *qnx4_checkroot(struct super_block *sb)
152 {
153 struct buffer_head *bh;
154 struct qnx4_inode_entry *rootdir;
155 int rd, rl;
156 int i, j;
157
158 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/')
159 return "no qnx4 filesystem (no root dir).";
160 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
161 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
162 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
163 for (j = 0; j < rl; j++) {
164 bh = sb_bread(sb, rd + j); /* root dir, first block */
165 if (bh == NULL)
166 return "unable to read root entry.";
167 rootdir = (struct qnx4_inode_entry *) bh->b_data;
168 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
169 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
170 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
171 continue;
172 qnx4_sb(sb)->BitMap = kmemdup(rootdir,
173 sizeof(struct qnx4_inode_entry),
174 GFP_KERNEL);
175 brelse(bh);
176 if (!qnx4_sb(sb)->BitMap)
177 return "not enough memory for bitmap inode";
178 /* keep bitmap inode known */
179 return NULL;
180 }
181 brelse(bh);
182 }
183 return "bitmap file not found.";
184 }
185
qnx4_fill_super(struct super_block * s,void * data,int silent)186 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
187 {
188 struct buffer_head *bh;
189 struct inode *root;
190 const char *errmsg;
191 struct qnx4_sb_info *qs;
192 int ret = -EINVAL;
193
194 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
195 if (!qs)
196 return -ENOMEM;
197 s->s_fs_info = qs;
198
199 sb_set_blocksize(s, QNX4_BLOCK_SIZE);
200
201 /* Check the superblock signature. Since the qnx4 code is
202 dangerous, we should leave as quickly as possible
203 if we don't belong here... */
204 bh = sb_bread(s, 1);
205 if (!bh) {
206 printk(KERN_ERR "qnx4: unable to read the superblock\n");
207 goto outnobh;
208 }
209 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
210 if (!silent)
211 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
212 goto out;
213 }
214 s->s_op = &qnx4_sops;
215 s->s_magic = QNX4_SUPER_MAGIC;
216 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
217 qnx4_sb(s)->sb_buf = bh;
218 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
219
220
221 /* check before allocating dentries, inodes, .. */
222 errmsg = qnx4_checkroot(s);
223 if (errmsg != NULL) {
224 if (!silent)
225 printk(KERN_ERR "qnx4: %s\n", errmsg);
226 goto out;
227 }
228
229 /* does root not have inode number QNX4_ROOT_INO ?? */
230 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
231 if (IS_ERR(root)) {
232 printk(KERN_ERR "qnx4: get inode failed\n");
233 ret = PTR_ERR(root);
234 goto outb;
235 }
236
237 ret = -ENOMEM;
238 s->s_root = d_make_root(root);
239 if (s->s_root == NULL)
240 goto outb;
241
242 brelse(bh);
243 return 0;
244
245 outb:
246 kfree(qs->BitMap);
247 out:
248 brelse(bh);
249 outnobh:
250 kfree(qs);
251 s->s_fs_info = NULL;
252 return ret;
253 }
254
qnx4_put_super(struct super_block * sb)255 static void qnx4_put_super(struct super_block *sb)
256 {
257 struct qnx4_sb_info *qs = qnx4_sb(sb);
258 kfree( qs->BitMap );
259 kfree( qs );
260 sb->s_fs_info = NULL;
261 return;
262 }
263
qnx4_readpage(struct file * file,struct page * page)264 static int qnx4_readpage(struct file *file, struct page *page)
265 {
266 return block_read_full_page(page,qnx4_get_block);
267 }
268
qnx4_bmap(struct address_space * mapping,sector_t block)269 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
270 {
271 return generic_block_bmap(mapping,block,qnx4_get_block);
272 }
273 static const struct address_space_operations qnx4_aops = {
274 .readpage = qnx4_readpage,
275 .bmap = qnx4_bmap
276 };
277
qnx4_iget(struct super_block * sb,unsigned long ino)278 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
279 {
280 struct buffer_head *bh;
281 struct qnx4_inode_entry *raw_inode;
282 int block;
283 struct qnx4_inode_entry *qnx4_inode;
284 struct inode *inode;
285
286 inode = iget_locked(sb, ino);
287 if (!inode)
288 return ERR_PTR(-ENOMEM);
289 if (!(inode->i_state & I_NEW))
290 return inode;
291
292 qnx4_inode = qnx4_raw_inode(inode);
293 inode->i_mode = 0;
294
295 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
296 if (!ino) {
297 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
298 "out of range\n",
299 sb->s_id, ino);
300 iget_failed(inode);
301 return ERR_PTR(-EIO);
302 }
303 block = ino / QNX4_INODES_PER_BLOCK;
304
305 if (!(bh = sb_bread(sb, block))) {
306 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
307 "%s\n", sb->s_id);
308 iget_failed(inode);
309 return ERR_PTR(-EIO);
310 }
311 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
312 (ino % QNX4_INODES_PER_BLOCK);
313
314 inode->i_mode = le16_to_cpu(raw_inode->di_mode);
315 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid);
316 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid);
317 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
318 inode->i_size = le32_to_cpu(raw_inode->di_size);
319 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
320 inode->i_mtime.tv_nsec = 0;
321 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
322 inode->i_atime.tv_nsec = 0;
323 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
324 inode->i_ctime.tv_nsec = 0;
325 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
326
327 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
328 if (S_ISREG(inode->i_mode)) {
329 inode->i_fop = &generic_ro_fops;
330 inode->i_mapping->a_ops = &qnx4_aops;
331 qnx4_i(inode)->mmu_private = inode->i_size;
332 } else if (S_ISDIR(inode->i_mode)) {
333 inode->i_op = &qnx4_dir_inode_operations;
334 inode->i_fop = &qnx4_dir_operations;
335 } else if (S_ISLNK(inode->i_mode)) {
336 inode->i_op = &page_symlink_inode_operations;
337 inode->i_mapping->a_ops = &qnx4_aops;
338 qnx4_i(inode)->mmu_private = inode->i_size;
339 } else {
340 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
341 ino, sb->s_id);
342 iget_failed(inode);
343 brelse(bh);
344 return ERR_PTR(-EIO);
345 }
346 brelse(bh);
347 unlock_new_inode(inode);
348 return inode;
349 }
350
351 static struct kmem_cache *qnx4_inode_cachep;
352
qnx4_alloc_inode(struct super_block * sb)353 static struct inode *qnx4_alloc_inode(struct super_block *sb)
354 {
355 struct qnx4_inode_info *ei;
356 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
357 if (!ei)
358 return NULL;
359 return &ei->vfs_inode;
360 }
361
qnx4_i_callback(struct rcu_head * head)362 static void qnx4_i_callback(struct rcu_head *head)
363 {
364 struct inode *inode = container_of(head, struct inode, i_rcu);
365 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
366 }
367
qnx4_destroy_inode(struct inode * inode)368 static void qnx4_destroy_inode(struct inode *inode)
369 {
370 call_rcu(&inode->i_rcu, qnx4_i_callback);
371 }
372
init_once(void * foo)373 static void init_once(void *foo)
374 {
375 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
376
377 inode_init_once(&ei->vfs_inode);
378 }
379
init_inodecache(void)380 static int init_inodecache(void)
381 {
382 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
383 sizeof(struct qnx4_inode_info),
384 0, (SLAB_RECLAIM_ACCOUNT|
385 SLAB_MEM_SPREAD),
386 init_once);
387 if (qnx4_inode_cachep == NULL)
388 return -ENOMEM;
389 return 0;
390 }
391
destroy_inodecache(void)392 static void destroy_inodecache(void)
393 {
394 kmem_cache_destroy(qnx4_inode_cachep);
395 }
396
qnx4_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)397 static struct dentry *qnx4_mount(struct file_system_type *fs_type,
398 int flags, const char *dev_name, void *data)
399 {
400 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
401 }
402
403 static struct file_system_type qnx4_fs_type = {
404 .owner = THIS_MODULE,
405 .name = "qnx4",
406 .mount = qnx4_mount,
407 .kill_sb = kill_block_super,
408 .fs_flags = FS_REQUIRES_DEV,
409 };
410
init_qnx4_fs(void)411 static int __init init_qnx4_fs(void)
412 {
413 int err;
414
415 err = init_inodecache();
416 if (err)
417 return err;
418
419 err = register_filesystem(&qnx4_fs_type);
420 if (err) {
421 destroy_inodecache();
422 return err;
423 }
424
425 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
426 return 0;
427 }
428
exit_qnx4_fs(void)429 static void __exit exit_qnx4_fs(void)
430 {
431 unregister_filesystem(&qnx4_fs_type);
432 destroy_inodecache();
433 }
434
435 module_init(init_qnx4_fs)
436 module_exit(exit_qnx4_fs)
437 MODULE_LICENSE("GPL");
438
439