1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * QNX4 file system, Linux implementation.
4 *
5 * Version : 0.2.1
6 *
7 * Using parts of the xiafs filesystem.
8 *
9 * History :
10 *
11 * 01-06-1998 by Richard Frowijn : first release.
12 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
13 * 30-06-1998 by Frank Denis : first step to write inodes.
14 */
15
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/highuid.h>
20 #include <linux/pagemap.h>
21 #include <linux/buffer_head.h>
22 #include <linux/writeback.h>
23 #include <linux/statfs.h>
24 #include "qnx4.h"
25
26 #define QNX4_VERSION 4
27 #define QNX4_BMNAME ".bitmap"
28
29 static const struct super_operations qnx4_sops;
30
31 static struct inode *qnx4_alloc_inode(struct super_block *sb);
32 static void qnx4_free_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 .free_inode = qnx4_free_inode,
40 .statfs = qnx4_statfs,
41 .remount_fs = qnx4_remount,
42 };
43
qnx4_remount(struct super_block * sb,int * flags,char * data)44 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
45 {
46 struct qnx4_sb_info *qs;
47
48 sync_filesystem(sb);
49 qs = qnx4_sb(sb);
50 qs->Version = QNX4_VERSION;
51 *flags |= SB_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 = u64_to_fsid(id);
141
142 return 0;
143 }
144
145 /*
146 * Check the root directory of the filesystem to make sure
147 * it really _is_ a qnx4 filesystem, and to check the size
148 * of the directory entry.
149 */
qnx4_checkroot(struct super_block * sb,struct qnx4_super_block * s)150 static const char *qnx4_checkroot(struct super_block *sb,
151 struct qnx4_super_block *s)
152 {
153 struct buffer_head *bh;
154 struct qnx4_inode_entry *rootdir;
155 int rd, rl;
156 int i, j;
157
158 if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0')
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(s->RootDir.di_first_xtnt.xtnt_blk) - 1;
162 rl = le32_to_cpu(s->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
193 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
194 if (!qs)
195 return -ENOMEM;
196 s->s_fs_info = qs;
197
198 sb_set_blocksize(s, QNX4_BLOCK_SIZE);
199
200 s->s_op = &qnx4_sops;
201 s->s_magic = QNX4_SUPER_MAGIC;
202 s->s_flags |= SB_RDONLY; /* Yup, read-only yet */
203 s->s_time_min = 0;
204 s->s_time_max = U32_MAX;
205
206 /* Check the superblock signature. Since the qnx4 code is
207 dangerous, we should leave as quickly as possible
208 if we don't belong here... */
209 bh = sb_bread(s, 1);
210 if (!bh) {
211 printk(KERN_ERR "qnx4: unable to read the superblock\n");
212 return -EINVAL;
213 }
214
215 /* check before allocating dentries, inodes, .. */
216 errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data);
217 brelse(bh);
218 if (errmsg != NULL) {
219 if (!silent)
220 printk(KERN_ERR "qnx4: %s\n", errmsg);
221 return -EINVAL;
222 }
223
224 /* does root not have inode number QNX4_ROOT_INO ?? */
225 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
226 if (IS_ERR(root)) {
227 printk(KERN_ERR "qnx4: get inode failed\n");
228 return PTR_ERR(root);
229 }
230
231 s->s_root = d_make_root(root);
232 if (s->s_root == NULL)
233 return -ENOMEM;
234
235 return 0;
236 }
237
qnx4_kill_sb(struct super_block * sb)238 static void qnx4_kill_sb(struct super_block *sb)
239 {
240 struct qnx4_sb_info *qs = qnx4_sb(sb);
241 kill_block_super(sb);
242 if (qs) {
243 kfree(qs->BitMap);
244 kfree(qs);
245 }
246 }
247
qnx4_read_folio(struct file * file,struct folio * folio)248 static int qnx4_read_folio(struct file *file, struct folio *folio)
249 {
250 return block_read_full_folio(folio, qnx4_get_block);
251 }
252
qnx4_bmap(struct address_space * mapping,sector_t block)253 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
254 {
255 return generic_block_bmap(mapping,block,qnx4_get_block);
256 }
257
258 static const struct address_space_operations qnx4_aops = {
259 .read_folio = qnx4_read_folio,
260 .bmap = qnx4_bmap
261 };
262
qnx4_iget(struct super_block * sb,unsigned long ino)263 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
264 {
265 struct buffer_head *bh;
266 struct qnx4_inode_entry *raw_inode;
267 int block;
268 struct qnx4_inode_entry *qnx4_inode;
269 struct inode *inode;
270
271 inode = iget_locked(sb, ino);
272 if (!inode)
273 return ERR_PTR(-ENOMEM);
274 if (!(inode->i_state & I_NEW))
275 return inode;
276
277 qnx4_inode = qnx4_raw_inode(inode);
278 inode->i_mode = 0;
279
280 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
281 if (!ino) {
282 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
283 "out of range\n",
284 sb->s_id, ino);
285 iget_failed(inode);
286 return ERR_PTR(-EIO);
287 }
288 block = ino / QNX4_INODES_PER_BLOCK;
289
290 if (!(bh = sb_bread(sb, block))) {
291 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
292 "%s\n", sb->s_id);
293 iget_failed(inode);
294 return ERR_PTR(-EIO);
295 }
296 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
297 (ino % QNX4_INODES_PER_BLOCK);
298
299 inode->i_mode = le16_to_cpu(raw_inode->di_mode);
300 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid));
301 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid));
302 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
303 inode->i_size = le32_to_cpu(raw_inode->di_size);
304 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
305 inode->i_mtime.tv_nsec = 0;
306 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
307 inode->i_atime.tv_nsec = 0;
308 inode_set_ctime(inode, le32_to_cpu(raw_inode->di_ctime), 0);
309 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
310
311 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
312 if (S_ISREG(inode->i_mode)) {
313 inode->i_fop = &generic_ro_fops;
314 inode->i_mapping->a_ops = &qnx4_aops;
315 qnx4_i(inode)->mmu_private = inode->i_size;
316 } else if (S_ISDIR(inode->i_mode)) {
317 inode->i_op = &qnx4_dir_inode_operations;
318 inode->i_fop = &qnx4_dir_operations;
319 } else if (S_ISLNK(inode->i_mode)) {
320 inode->i_op = &page_symlink_inode_operations;
321 inode_nohighmem(inode);
322 inode->i_mapping->a_ops = &qnx4_aops;
323 qnx4_i(inode)->mmu_private = inode->i_size;
324 } else {
325 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
326 ino, sb->s_id);
327 iget_failed(inode);
328 brelse(bh);
329 return ERR_PTR(-EIO);
330 }
331 brelse(bh);
332 unlock_new_inode(inode);
333 return inode;
334 }
335
336 static struct kmem_cache *qnx4_inode_cachep;
337
qnx4_alloc_inode(struct super_block * sb)338 static struct inode *qnx4_alloc_inode(struct super_block *sb)
339 {
340 struct qnx4_inode_info *ei;
341 ei = alloc_inode_sb(sb, qnx4_inode_cachep, GFP_KERNEL);
342 if (!ei)
343 return NULL;
344 return &ei->vfs_inode;
345 }
346
qnx4_free_inode(struct inode * inode)347 static void qnx4_free_inode(struct inode *inode)
348 {
349 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
350 }
351
init_once(void * foo)352 static void init_once(void *foo)
353 {
354 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
355
356 inode_init_once(&ei->vfs_inode);
357 }
358
init_inodecache(void)359 static int init_inodecache(void)
360 {
361 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
362 sizeof(struct qnx4_inode_info),
363 0, (SLAB_RECLAIM_ACCOUNT|
364 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
365 init_once);
366 if (qnx4_inode_cachep == NULL)
367 return -ENOMEM;
368 return 0;
369 }
370
destroy_inodecache(void)371 static void destroy_inodecache(void)
372 {
373 /*
374 * Make sure all delayed rcu free inodes are flushed before we
375 * destroy cache.
376 */
377 rcu_barrier();
378 kmem_cache_destroy(qnx4_inode_cachep);
379 }
380
qnx4_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)381 static struct dentry *qnx4_mount(struct file_system_type *fs_type,
382 int flags, const char *dev_name, void *data)
383 {
384 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
385 }
386
387 static struct file_system_type qnx4_fs_type = {
388 .owner = THIS_MODULE,
389 .name = "qnx4",
390 .mount = qnx4_mount,
391 .kill_sb = qnx4_kill_sb,
392 .fs_flags = FS_REQUIRES_DEV,
393 };
394 MODULE_ALIAS_FS("qnx4");
395
init_qnx4_fs(void)396 static int __init init_qnx4_fs(void)
397 {
398 int err;
399
400 err = init_inodecache();
401 if (err)
402 return err;
403
404 err = register_filesystem(&qnx4_fs_type);
405 if (err) {
406 destroy_inodecache();
407 return err;
408 }
409
410 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
411 return 0;
412 }
413
exit_qnx4_fs(void)414 static void __exit exit_qnx4_fs(void)
415 {
416 unregister_filesystem(&qnx4_fs_type);
417 destroy_inodecache();
418 }
419
420 module_init(init_qnx4_fs)
421 module_exit(exit_qnx4_fs)
422 MODULE_LICENSE("GPL");
423
424