qnx4: di_fname is an array, for crying out loud...
[omap4-v4l2-camera:smertz-omap4-v4l2-camera.git] / fs / qnx4 / inode.c
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
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
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
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
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
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
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  */
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                                 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
198                                 if (!strcmp(rootdir->di_fname,
199                                             QNX4_BMNAME)) {
200                                         found = 1;
201                                         qnx4_sb(sb)->BitMap = kmemdup(rootdir,
202                                                                       sizeof(struct qnx4_inode_entry),
203                                                                       GFP_KERNEL);
204                                         if (!qnx4_sb(sb)->BitMap) {
205                                                 brelse (bh);
206                                                 return "not enough memory for bitmap inode";
207                                         }/* keep bitmap inode known */
208                                         break;
209                                 }
210                         }
211                         brelse(bh);
212                         if (found != 0) {
213                                 break;
214                         }
215                 }
216                 if (found == 0) {
217                         return "bitmap file not found.";
218                 }
219         }
220         return NULL;
221 }
222
223 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
224 {
225         struct buffer_head *bh;
226         struct inode *root;
227         const char *errmsg;
228         struct qnx4_sb_info *qs;
229         int ret = -EINVAL;
230
231         qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
232         if (!qs)
233                 return -ENOMEM;
234         s->s_fs_info = qs;
235
236         sb_set_blocksize(s, QNX4_BLOCK_SIZE);
237
238         /* Check the superblock signature. Since the qnx4 code is
239            dangerous, we should leave as quickly as possible
240            if we don't belong here... */
241         bh = sb_bread(s, 1);
242         if (!bh) {
243                 printk(KERN_ERR "qnx4: unable to read the superblock\n");
244                 goto outnobh;
245         }
246         if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
247                 if (!silent)
248                         printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
249                 goto out;
250         }
251         s->s_op = &qnx4_sops;
252         s->s_magic = QNX4_SUPER_MAGIC;
253         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
254         qnx4_sb(s)->sb_buf = bh;
255         qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
256
257
258         /* check before allocating dentries, inodes, .. */
259         errmsg = qnx4_checkroot(s);
260         if (errmsg != NULL) {
261                 if (!silent)
262                         printk(KERN_ERR "qnx4: %s\n", errmsg);
263                 goto out;
264         }
265
266         /* does root not have inode number QNX4_ROOT_INO ?? */
267         root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
268         if (IS_ERR(root)) {
269                 printk(KERN_ERR "qnx4: get inode failed\n");
270                 ret = PTR_ERR(root);
271                 goto out;
272         }
273
274         ret = -ENOMEM;
275         s->s_root = d_alloc_root(root);
276         if (s->s_root == NULL)
277                 goto outi;
278
279         brelse(bh);
280         return 0;
281
282       outi:
283         iput(root);
284       out:
285         brelse(bh);
286       outnobh:
287         kfree(qs);
288         s->s_fs_info = NULL;
289         return ret;
290 }
291
292 static void qnx4_put_super(struct super_block *sb)
293 {
294         struct qnx4_sb_info *qs = qnx4_sb(sb);
295         kfree( qs->BitMap );
296         kfree( qs );
297         sb->s_fs_info = NULL;
298         return;
299 }
300
301 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
302 {
303         return block_write_full_page(page,qnx4_get_block, wbc);
304 }
305
306 static int qnx4_readpage(struct file *file, struct page *page)
307 {
308         return block_read_full_page(page,qnx4_get_block);
309 }
310
311 static int qnx4_write_begin(struct file *file, struct address_space *mapping,
312                         loff_t pos, unsigned len, unsigned flags,
313                         struct page **pagep, void **fsdata)
314 {
315         struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
316         int ret;
317
318         *pagep = NULL;
319         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
320                                 qnx4_get_block,
321                                 &qnx4_inode->mmu_private);
322         if (unlikely(ret)) {
323                 loff_t isize = mapping->host->i_size;
324                 if (pos + len > isize)
325                         vmtruncate(mapping->host, isize);
326         }
327
328         return ret;
329 }
330 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
331 {
332         return generic_block_bmap(mapping,block,qnx4_get_block);
333 }
334 static const struct address_space_operations qnx4_aops = {
335         .readpage       = qnx4_readpage,
336         .writepage      = qnx4_writepage,
337         .write_begin    = qnx4_write_begin,
338         .write_end      = generic_write_end,
339         .bmap           = qnx4_bmap
340 };
341
342 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
343 {
344         struct buffer_head *bh;
345         struct qnx4_inode_entry *raw_inode;
346         int block;
347         struct qnx4_inode_entry *qnx4_inode;
348         struct inode *inode;
349
350         inode = iget_locked(sb, ino);
351         if (!inode)
352                 return ERR_PTR(-ENOMEM);
353         if (!(inode->i_state & I_NEW))
354                 return inode;
355
356         qnx4_inode = qnx4_raw_inode(inode);
357         inode->i_mode = 0;
358
359         QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
360         if (!ino) {
361                 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
362                                 "out of range\n",
363                        sb->s_id, ino);
364                 iget_failed(inode);
365                 return ERR_PTR(-EIO);
366         }
367         block = ino / QNX4_INODES_PER_BLOCK;
368
369         if (!(bh = sb_bread(sb, block))) {
370                 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
371                        "%s\n", sb->s_id);
372                 iget_failed(inode);
373                 return ERR_PTR(-EIO);
374         }
375         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
376             (ino % QNX4_INODES_PER_BLOCK);
377
378         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
379         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
380         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
381         set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
382         inode->i_size    = le32_to_cpu(raw_inode->di_size);
383         inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
384         inode->i_mtime.tv_nsec = 0;
385         inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
386         inode->i_atime.tv_nsec = 0;
387         inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
388         inode->i_ctime.tv_nsec = 0;
389         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
390
391         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
392         if (S_ISREG(inode->i_mode)) {
393                 inode->i_fop = &generic_ro_fops;
394                 inode->i_mapping->a_ops = &qnx4_aops;
395                 qnx4_i(inode)->mmu_private = inode->i_size;
396         } else if (S_ISDIR(inode->i_mode)) {
397                 inode->i_op = &qnx4_dir_inode_operations;
398                 inode->i_fop = &qnx4_dir_operations;
399         } else if (S_ISLNK(inode->i_mode)) {
400                 inode->i_op = &page_symlink_inode_operations;
401                 inode->i_mapping->a_ops = &qnx4_aops;
402                 qnx4_i(inode)->mmu_private = inode->i_size;
403         } else {
404                 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
405                         ino, sb->s_id);
406                 iget_failed(inode);
407                 brelse(bh);
408                 return ERR_PTR(-EIO);
409         }
410         brelse(bh);
411         unlock_new_inode(inode);
412         return inode;
413 }
414
415 static struct kmem_cache *qnx4_inode_cachep;
416
417 static struct inode *qnx4_alloc_inode(struct super_block *sb)
418 {
419         struct qnx4_inode_info *ei;
420         ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
421         if (!ei)
422                 return NULL;
423         return &ei->vfs_inode;
424 }
425
426 static void qnx4_i_callback(struct rcu_head *head)
427 {
428         struct inode *inode = container_of(head, struct inode, i_rcu);
429         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
430 }
431
432 static void qnx4_destroy_inode(struct inode *inode)
433 {
434         call_rcu(&inode->i_rcu, qnx4_i_callback);
435 }
436
437 static void init_once(void *foo)
438 {
439         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
440
441         inode_init_once(&ei->vfs_inode);
442 }
443
444 static int init_inodecache(void)
445 {
446         qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
447                                              sizeof(struct qnx4_inode_info),
448                                              0, (SLAB_RECLAIM_ACCOUNT|
449                                                 SLAB_MEM_SPREAD),
450                                              init_once);
451         if (qnx4_inode_cachep == NULL)
452                 return -ENOMEM;
453         return 0;
454 }
455
456 static void destroy_inodecache(void)
457 {
458         kmem_cache_destroy(qnx4_inode_cachep);
459 }
460
461 static struct dentry *qnx4_mount(struct file_system_type *fs_type,
462         int flags, const char *dev_name, void *data)
463 {
464         return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
465 }
466
467 static struct file_system_type qnx4_fs_type = {
468         .owner          = THIS_MODULE,
469         .name           = "qnx4",
470         .mount          = qnx4_mount,
471         .kill_sb        = kill_block_super,
472         .fs_flags       = FS_REQUIRES_DEV,
473 };
474
475 static int __init init_qnx4_fs(void)
476 {
477         int err;
478
479         err = init_inodecache();
480         if (err)
481                 return err;
482
483         err = register_filesystem(&qnx4_fs_type);
484         if (err) {
485                 destroy_inodecache();
486                 return err;
487         }
488
489         printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
490         return 0;
491 }
492
493 static void __exit exit_qnx4_fs(void)
494 {
495         unregister_filesystem(&qnx4_fs_type);
496         destroy_inodecache();
497 }
498
499 module_init(init_qnx4_fs)
500 module_exit(exit_qnx4_fs)
501 MODULE_LICENSE("GPL");
502