1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * fs/bfs/inode.c
4 * BFS superblock and inode operations.
5 * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
6 * From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
7 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
8 */
9
10 #include <linux/module.h>
11 #include <linux/mm.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/fs.h>
15 #include <linux/buffer_head.h>
16 #include <linux/vfs.h>
17 #include <linux/writeback.h>
18 #include <linux/uio.h>
19 #include <linux/uaccess.h>
20 #include <linux/fs_context.h>
21 #include "bfs.h"
22
23 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
24 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
25 MODULE_LICENSE("GPL");
26
27 #undef DEBUG
28
29 #ifdef DEBUG
30 #define dprintf(x...) printf(x)
31 #else
32 #define dprintf(x...)
33 #endif
34
bfs_iget(struct super_block * sb,unsigned long ino)35 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
36 {
37 struct bfs_inode *di;
38 struct inode *inode;
39 struct buffer_head *bh;
40 int block, off;
41
42 inode = iget_locked(sb, ino);
43 if (!inode)
44 return ERR_PTR(-ENOMEM);
45 if (!(inode->i_state & I_NEW))
46 return inode;
47
48 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
49 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
50 goto error;
51 }
52
53 block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
54 bh = sb_bread(inode->i_sb, block);
55 if (!bh) {
56 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
57 ino);
58 goto error;
59 }
60
61 off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
62 di = (struct bfs_inode *)bh->b_data + off;
63
64 inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
65 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
66 inode->i_mode |= S_IFDIR;
67 inode->i_op = &bfs_dir_inops;
68 inode->i_fop = &bfs_dir_operations;
69 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
70 inode->i_mode |= S_IFREG;
71 inode->i_op = &bfs_file_inops;
72 inode->i_fop = &bfs_file_operations;
73 inode->i_mapping->a_ops = &bfs_aops;
74 }
75
76 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
77 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
78 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
79 i_uid_write(inode, le32_to_cpu(di->i_uid));
80 i_gid_write(inode, le32_to_cpu(di->i_gid));
81 set_nlink(inode, le32_to_cpu(di->i_nlink));
82 inode->i_size = BFS_FILESIZE(di);
83 inode->i_blocks = BFS_FILEBLOCKS(di);
84 inode_set_atime(inode, le32_to_cpu(di->i_atime), 0);
85 inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0);
86 inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);
87
88 brelse(bh);
89 unlock_new_inode(inode);
90 return inode;
91
92 error:
93 iget_failed(inode);
94 return ERR_PTR(-EIO);
95 }
96
find_inode(struct super_block * sb,u16 ino,struct buffer_head ** p)97 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
98 {
99 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
100 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
101 return ERR_PTR(-EIO);
102 }
103
104 ino -= BFS_ROOT_INO;
105
106 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
107 if (!*p) {
108 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
109 return ERR_PTR(-EIO);
110 }
111
112 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
113 }
114
bfs_write_inode(struct inode * inode,struct writeback_control * wbc)115 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
116 {
117 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
118 unsigned int ino = (u16)inode->i_ino;
119 unsigned long i_sblock;
120 struct bfs_inode *di;
121 struct buffer_head *bh;
122 int err = 0;
123
124 dprintf("ino=%08x\n", ino);
125
126 di = find_inode(inode->i_sb, ino, &bh);
127 if (IS_ERR(di))
128 return PTR_ERR(di);
129
130 mutex_lock(&info->bfs_lock);
131
132 if (ino == BFS_ROOT_INO)
133 di->i_vtype = cpu_to_le32(BFS_VDIR);
134 else
135 di->i_vtype = cpu_to_le32(BFS_VREG);
136
137 di->i_ino = cpu_to_le16(ino);
138 di->i_mode = cpu_to_le32(inode->i_mode);
139 di->i_uid = cpu_to_le32(i_uid_read(inode));
140 di->i_gid = cpu_to_le32(i_gid_read(inode));
141 di->i_nlink = cpu_to_le32(inode->i_nlink);
142 di->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
143 di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
144 di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
145 i_sblock = BFS_I(inode)->i_sblock;
146 di->i_sblock = cpu_to_le32(i_sblock);
147 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
148 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
149
150 mark_buffer_dirty(bh);
151 if (wbc->sync_mode == WB_SYNC_ALL) {
152 sync_dirty_buffer(bh);
153 if (buffer_req(bh) && !buffer_uptodate(bh))
154 err = -EIO;
155 }
156 brelse(bh);
157 mutex_unlock(&info->bfs_lock);
158 return err;
159 }
160
bfs_evict_inode(struct inode * inode)161 static void bfs_evict_inode(struct inode *inode)
162 {
163 unsigned long ino = inode->i_ino;
164 struct bfs_inode *di;
165 struct buffer_head *bh;
166 struct super_block *s = inode->i_sb;
167 struct bfs_sb_info *info = BFS_SB(s);
168 struct bfs_inode_info *bi = BFS_I(inode);
169
170 dprintf("ino=%08lx\n", ino);
171
172 truncate_inode_pages_final(&inode->i_data);
173 invalidate_inode_buffers(inode);
174 clear_inode(inode);
175
176 if (inode->i_nlink)
177 return;
178
179 di = find_inode(s, inode->i_ino, &bh);
180 if (IS_ERR(di))
181 return;
182
183 mutex_lock(&info->bfs_lock);
184 /* clear on-disk inode */
185 memset(di, 0, sizeof(struct bfs_inode));
186 mark_buffer_dirty(bh);
187 brelse(bh);
188
189 if (bi->i_dsk_ino) {
190 if (bi->i_sblock)
191 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
192 info->si_freei++;
193 clear_bit(ino, info->si_imap);
194 bfs_dump_imap("evict_inode", s);
195 }
196
197 /*
198 * If this was the last file, make the previous block
199 * "last block of the last file" even if there is no
200 * real file there, saves us 1 gap.
201 */
202 if (info->si_lf_eblk == bi->i_eblock)
203 info->si_lf_eblk = bi->i_sblock - 1;
204 mutex_unlock(&info->bfs_lock);
205 }
206
bfs_put_super(struct super_block * s)207 static void bfs_put_super(struct super_block *s)
208 {
209 struct bfs_sb_info *info = BFS_SB(s);
210
211 if (!info)
212 return;
213
214 mutex_destroy(&info->bfs_lock);
215 kfree(info);
216 s->s_fs_info = NULL;
217 }
218
bfs_statfs(struct dentry * dentry,struct kstatfs * buf)219 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
220 {
221 struct super_block *s = dentry->d_sb;
222 struct bfs_sb_info *info = BFS_SB(s);
223 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
224 buf->f_type = BFS_MAGIC;
225 buf->f_bsize = s->s_blocksize;
226 buf->f_blocks = info->si_blocks;
227 buf->f_bfree = buf->f_bavail = info->si_freeb;
228 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
229 buf->f_ffree = info->si_freei;
230 buf->f_fsid = u64_to_fsid(id);
231 buf->f_namelen = BFS_NAMELEN;
232 return 0;
233 }
234
235 static struct kmem_cache *bfs_inode_cachep;
236
bfs_alloc_inode(struct super_block * sb)237 static struct inode *bfs_alloc_inode(struct super_block *sb)
238 {
239 struct bfs_inode_info *bi;
240 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
241 if (!bi)
242 return NULL;
243 return &bi->vfs_inode;
244 }
245
bfs_free_inode(struct inode * inode)246 static void bfs_free_inode(struct inode *inode)
247 {
248 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
249 }
250
init_once(void * foo)251 static void init_once(void *foo)
252 {
253 struct bfs_inode_info *bi = foo;
254
255 inode_init_once(&bi->vfs_inode);
256 }
257
init_inodecache(void)258 static int __init init_inodecache(void)
259 {
260 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
261 sizeof(struct bfs_inode_info),
262 0, (SLAB_RECLAIM_ACCOUNT|
263 SLAB_ACCOUNT),
264 init_once);
265 if (bfs_inode_cachep == NULL)
266 return -ENOMEM;
267 return 0;
268 }
269
destroy_inodecache(void)270 static void destroy_inodecache(void)
271 {
272 /*
273 * Make sure all delayed rcu free inodes are flushed before we
274 * destroy cache.
275 */
276 rcu_barrier();
277 kmem_cache_destroy(bfs_inode_cachep);
278 }
279
280 static const struct super_operations bfs_sops = {
281 .alloc_inode = bfs_alloc_inode,
282 .free_inode = bfs_free_inode,
283 .write_inode = bfs_write_inode,
284 .evict_inode = bfs_evict_inode,
285 .put_super = bfs_put_super,
286 .statfs = bfs_statfs,
287 };
288
bfs_dump_imap(const char * prefix,struct super_block * s)289 void bfs_dump_imap(const char *prefix, struct super_block *s)
290 {
291 #ifdef DEBUG
292 int i;
293 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
294
295 if (!tmpbuf)
296 return;
297 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
298 if (i > PAGE_SIZE - 100) break;
299 if (test_bit(i, BFS_SB(s)->si_imap))
300 strcat(tmpbuf, "1");
301 else
302 strcat(tmpbuf, "0");
303 }
304 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
305 free_page((unsigned long)tmpbuf);
306 #endif
307 }
308
bfs_fill_super(struct super_block * s,struct fs_context * fc)309 static int bfs_fill_super(struct super_block *s, struct fs_context *fc)
310 {
311 struct buffer_head *bh, *sbh;
312 struct bfs_super_block *bfs_sb;
313 struct inode *inode;
314 unsigned i;
315 struct bfs_sb_info *info;
316 int ret = -EINVAL;
317 unsigned long i_sblock, i_eblock, i_eoff, s_size;
318 int silent = fc->sb_flags & SB_SILENT;
319
320 info = kzalloc(sizeof(*info), GFP_KERNEL);
321 if (!info)
322 return -ENOMEM;
323 mutex_init(&info->bfs_lock);
324 s->s_fs_info = info;
325 s->s_time_min = 0;
326 s->s_time_max = U32_MAX;
327
328 sb_set_blocksize(s, BFS_BSIZE);
329
330 sbh = sb_bread(s, 0);
331 if (!sbh)
332 goto out;
333 bfs_sb = (struct bfs_super_block *)sbh->b_data;
334 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
335 if (!silent)
336 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic));
337 goto out1;
338 }
339 if (BFS_UNCLEAN(bfs_sb, s) && !silent)
340 printf("%s is unclean, continuing\n", s->s_id);
341
342 s->s_magic = BFS_MAGIC;
343
344 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
345 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
346 printf("Superblock is corrupted on %s\n", s->s_id);
347 goto out1;
348 }
349
350 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
351 if (info->si_lasti == BFS_MAX_LASTI)
352 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
353 else if (info->si_lasti > BFS_MAX_LASTI) {
354 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
355 goto out1;
356 }
357 for (i = 0; i < BFS_ROOT_INO; i++)
358 set_bit(i, info->si_imap);
359
360 s->s_op = &bfs_sops;
361 inode = bfs_iget(s, BFS_ROOT_INO);
362 if (IS_ERR(inode)) {
363 ret = PTR_ERR(inode);
364 goto out1;
365 }
366 s->s_root = d_make_root(inode);
367 if (!s->s_root) {
368 ret = -ENOMEM;
369 goto out1;
370 }
371
372 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
373 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
374 info->si_freei = 0;
375 info->si_lf_eblk = 0;
376
377 /* can we read the last block? */
378 bh = sb_bread(s, info->si_blocks - 1);
379 if (!bh) {
380 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
381 ret = -EIO;
382 goto out2;
383 }
384 brelse(bh);
385
386 bh = NULL;
387 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
388 struct bfs_inode *di;
389 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
390 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
391 unsigned long eblock;
392
393 if (!off) {
394 brelse(bh);
395 bh = sb_bread(s, block);
396 }
397
398 if (!bh)
399 continue;
400
401 di = (struct bfs_inode *)bh->b_data + off;
402
403 /* test if filesystem is not corrupted */
404
405 i_eoff = le32_to_cpu(di->i_eoffset);
406 i_sblock = le32_to_cpu(di->i_sblock);
407 i_eblock = le32_to_cpu(di->i_eblock);
408 s_size = le32_to_cpu(bfs_sb->s_end);
409
410 if (i_sblock > info->si_blocks ||
411 i_eblock > info->si_blocks ||
412 i_sblock > i_eblock ||
413 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
414 i_sblock * BFS_BSIZE > i_eoff) {
415
416 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
417
418 brelse(bh);
419 ret = -EIO;
420 goto out2;
421 }
422
423 if (!di->i_ino) {
424 info->si_freei++;
425 continue;
426 }
427 set_bit(i, info->si_imap);
428 info->si_freeb -= BFS_FILEBLOCKS(di);
429
430 eblock = le32_to_cpu(di->i_eblock);
431 if (eblock > info->si_lf_eblk)
432 info->si_lf_eblk = eblock;
433 }
434 brelse(bh);
435 brelse(sbh);
436 bfs_dump_imap("fill_super", s);
437 return 0;
438
439 out2:
440 dput(s->s_root);
441 s->s_root = NULL;
442 out1:
443 brelse(sbh);
444 out:
445 mutex_destroy(&info->bfs_lock);
446 kfree(info);
447 s->s_fs_info = NULL;
448 return ret;
449 }
450
bfs_get_tree(struct fs_context * fc)451 static int bfs_get_tree(struct fs_context *fc)
452 {
453 return get_tree_bdev(fc, bfs_fill_super);
454 }
455
456 static const struct fs_context_operations bfs_context_ops = {
457 .get_tree = bfs_get_tree,
458 };
459
bfs_init_fs_context(struct fs_context * fc)460 static int bfs_init_fs_context(struct fs_context *fc)
461 {
462 fc->ops = &bfs_context_ops;
463
464 return 0;
465 }
466
467 static struct file_system_type bfs_fs_type = {
468 .owner = THIS_MODULE,
469 .name = "bfs",
470 .init_fs_context = bfs_init_fs_context,
471 .kill_sb = kill_block_super,
472 .fs_flags = FS_REQUIRES_DEV,
473 };
474 MODULE_ALIAS_FS("bfs");
475
init_bfs_fs(void)476 static int __init init_bfs_fs(void)
477 {
478 int err = init_inodecache();
479 if (err)
480 goto out1;
481 err = register_filesystem(&bfs_fs_type);
482 if (err)
483 goto out;
484 return 0;
485 out:
486 destroy_inodecache();
487 out1:
488 return err;
489 }
490
exit_bfs_fs(void)491 static void __exit exit_bfs_fs(void)
492 {
493 unregister_filesystem(&bfs_fs_type);
494 destroy_inodecache();
495 }
496
497 module_init(init_bfs_fs)
498 module_exit(exit_bfs_fs)
499