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 "bfs.h"
21
22 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
23 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
24 MODULE_LICENSE("GPL");
25
26 #undef DEBUG
27
28 #ifdef DEBUG
29 #define dprintf(x...) printf(x)
30 #else
31 #define dprintf(x...)
32 #endif
33
bfs_iget(struct super_block * sb,unsigned long ino)34 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
35 {
36 struct bfs_inode *di;
37 struct inode *inode;
38 struct buffer_head *bh;
39 int block, off;
40
41 inode = iget_locked(sb, ino);
42 if (!inode)
43 return ERR_PTR(-ENOMEM);
44 if (!(inode->i_state & I_NEW))
45 return inode;
46
47 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
48 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
49 goto error;
50 }
51
52 block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
53 bh = sb_bread(inode->i_sb, block);
54 if (!bh) {
55 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
56 ino);
57 goto error;
58 }
59
60 off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
61 di = (struct bfs_inode *)bh->b_data + off;
62
63 inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
64 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
65 inode->i_mode |= S_IFDIR;
66 inode->i_op = &bfs_dir_inops;
67 inode->i_fop = &bfs_dir_operations;
68 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
69 inode->i_mode |= S_IFREG;
70 inode->i_op = &bfs_file_inops;
71 inode->i_fop = &bfs_file_operations;
72 inode->i_mapping->a_ops = &bfs_aops;
73 }
74
75 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
76 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
77 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
78 i_uid_write(inode, le32_to_cpu(di->i_uid));
79 i_gid_write(inode, le32_to_cpu(di->i_gid));
80 set_nlink(inode, le32_to_cpu(di->i_nlink));
81 inode->i_size = BFS_FILESIZE(di);
82 inode->i_blocks = BFS_FILEBLOCKS(di);
83 inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
84 inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
85 inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);
86 inode->i_atime.tv_nsec = 0;
87 inode->i_mtime.tv_nsec = 0;
88
89 brelse(bh);
90 unlock_new_inode(inode);
91 return inode;
92
93 error:
94 iget_failed(inode);
95 return ERR_PTR(-EIO);
96 }
97
find_inode(struct super_block * sb,u16 ino,struct buffer_head ** p)98 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
99 {
100 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
101 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
102 return ERR_PTR(-EIO);
103 }
104
105 ino -= BFS_ROOT_INO;
106
107 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
108 if (!*p) {
109 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
110 return ERR_PTR(-EIO);
111 }
112
113 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
114 }
115
bfs_write_inode(struct inode * inode,struct writeback_control * wbc)116 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
117 {
118 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
119 unsigned int ino = (u16)inode->i_ino;
120 unsigned long i_sblock;
121 struct bfs_inode *di;
122 struct buffer_head *bh;
123 int err = 0;
124
125 dprintf("ino=%08x\n", ino);
126
127 di = find_inode(inode->i_sb, ino, &bh);
128 if (IS_ERR(di))
129 return PTR_ERR(di);
130
131 mutex_lock(&info->bfs_lock);
132
133 if (ino == BFS_ROOT_INO)
134 di->i_vtype = cpu_to_le32(BFS_VDIR);
135 else
136 di->i_vtype = cpu_to_le32(BFS_VREG);
137
138 di->i_ino = cpu_to_le16(ino);
139 di->i_mode = cpu_to_le32(inode->i_mode);
140 di->i_uid = cpu_to_le32(i_uid_read(inode));
141 di->i_gid = cpu_to_le32(i_gid_read(inode));
142 di->i_nlink = cpu_to_le32(inode->i_nlink);
143 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
144 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
145 di->i_ctime = cpu_to_le32(inode_get_ctime(inode).tv_sec);
146 i_sblock = BFS_I(inode)->i_sblock;
147 di->i_sblock = cpu_to_le32(i_sblock);
148 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
149 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
150
151 mark_buffer_dirty(bh);
152 if (wbc->sync_mode == WB_SYNC_ALL) {
153 sync_dirty_buffer(bh);
154 if (buffer_req(bh) && !buffer_uptodate(bh))
155 err = -EIO;
156 }
157 brelse(bh);
158 mutex_unlock(&info->bfs_lock);
159 return err;
160 }
161
bfs_evict_inode(struct inode * inode)162 static void bfs_evict_inode(struct inode *inode)
163 {
164 unsigned long ino = inode->i_ino;
165 struct bfs_inode *di;
166 struct buffer_head *bh;
167 struct super_block *s = inode->i_sb;
168 struct bfs_sb_info *info = BFS_SB(s);
169 struct bfs_inode_info *bi = BFS_I(inode);
170
171 dprintf("ino=%08lx\n", ino);
172
173 truncate_inode_pages_final(&inode->i_data);
174 invalidate_inode_buffers(inode);
175 clear_inode(inode);
176
177 if (inode->i_nlink)
178 return;
179
180 di = find_inode(s, inode->i_ino, &bh);
181 if (IS_ERR(di))
182 return;
183
184 mutex_lock(&info->bfs_lock);
185 /* clear on-disk inode */
186 memset(di, 0, sizeof(struct bfs_inode));
187 mark_buffer_dirty(bh);
188 brelse(bh);
189
190 if (bi->i_dsk_ino) {
191 if (bi->i_sblock)
192 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
193 info->si_freei++;
194 clear_bit(ino, info->si_imap);
195 bfs_dump_imap("evict_inode", s);
196 }
197
198 /*
199 * If this was the last file, make the previous block
200 * "last block of the last file" even if there is no
201 * real file there, saves us 1 gap.
202 */
203 if (info->si_lf_eblk == bi->i_eblock)
204 info->si_lf_eblk = bi->i_sblock - 1;
205 mutex_unlock(&info->bfs_lock);
206 }
207
bfs_put_super(struct super_block * s)208 static void bfs_put_super(struct super_block *s)
209 {
210 struct bfs_sb_info *info = BFS_SB(s);
211
212 if (!info)
213 return;
214
215 mutex_destroy(&info->bfs_lock);
216 kfree(info);
217 s->s_fs_info = NULL;
218 }
219
bfs_statfs(struct dentry * dentry,struct kstatfs * buf)220 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
221 {
222 struct super_block *s = dentry->d_sb;
223 struct bfs_sb_info *info = BFS_SB(s);
224 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
225 buf->f_type = BFS_MAGIC;
226 buf->f_bsize = s->s_blocksize;
227 buf->f_blocks = info->si_blocks;
228 buf->f_bfree = buf->f_bavail = info->si_freeb;
229 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
230 buf->f_ffree = info->si_freei;
231 buf->f_fsid = u64_to_fsid(id);
232 buf->f_namelen = BFS_NAMELEN;
233 return 0;
234 }
235
236 static struct kmem_cache *bfs_inode_cachep;
237
bfs_alloc_inode(struct super_block * sb)238 static struct inode *bfs_alloc_inode(struct super_block *sb)
239 {
240 struct bfs_inode_info *bi;
241 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
242 if (!bi)
243 return NULL;
244 return &bi->vfs_inode;
245 }
246
bfs_free_inode(struct inode * inode)247 static void bfs_free_inode(struct inode *inode)
248 {
249 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
250 }
251
init_once(void * foo)252 static void init_once(void *foo)
253 {
254 struct bfs_inode_info *bi = foo;
255
256 inode_init_once(&bi->vfs_inode);
257 }
258
init_inodecache(void)259 static int __init init_inodecache(void)
260 {
261 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
262 sizeof(struct bfs_inode_info),
263 0, (SLAB_RECLAIM_ACCOUNT|
264 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
265 init_once);
266 if (bfs_inode_cachep == NULL)
267 return -ENOMEM;
268 return 0;
269 }
270
destroy_inodecache(void)271 static void destroy_inodecache(void)
272 {
273 /*
274 * Make sure all delayed rcu free inodes are flushed before we
275 * destroy cache.
276 */
277 rcu_barrier();
278 kmem_cache_destroy(bfs_inode_cachep);
279 }
280
281 static const struct super_operations bfs_sops = {
282 .alloc_inode = bfs_alloc_inode,
283 .free_inode = bfs_free_inode,
284 .write_inode = bfs_write_inode,
285 .evict_inode = bfs_evict_inode,
286 .put_super = bfs_put_super,
287 .statfs = bfs_statfs,
288 };
289
bfs_dump_imap(const char * prefix,struct super_block * s)290 void bfs_dump_imap(const char *prefix, struct super_block *s)
291 {
292 #ifdef DEBUG
293 int i;
294 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
295
296 if (!tmpbuf)
297 return;
298 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
299 if (i > PAGE_SIZE - 100) break;
300 if (test_bit(i, BFS_SB(s)->si_imap))
301 strcat(tmpbuf, "1");
302 else
303 strcat(tmpbuf, "0");
304 }
305 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
306 free_page((unsigned long)tmpbuf);
307 #endif
308 }
309
bfs_fill_super(struct super_block * s,void * data,int silent)310 static int bfs_fill_super(struct super_block *s, void *data, int silent)
311 {
312 struct buffer_head *bh, *sbh;
313 struct bfs_super_block *bfs_sb;
314 struct inode *inode;
315 unsigned i;
316 struct bfs_sb_info *info;
317 int ret = -EINVAL;
318 unsigned long i_sblock, i_eblock, i_eoff, s_size;
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_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)451 static struct dentry *bfs_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, bfs_fill_super);
455 }
456
457 static struct file_system_type bfs_fs_type = {
458 .owner = THIS_MODULE,
459 .name = "bfs",
460 .mount = bfs_mount,
461 .kill_sb = kill_block_super,
462 .fs_flags = FS_REQUIRES_DEV,
463 };
464 MODULE_ALIAS_FS("bfs");
465
init_bfs_fs(void)466 static int __init init_bfs_fs(void)
467 {
468 int err = init_inodecache();
469 if (err)
470 goto out1;
471 err = register_filesystem(&bfs_fs_type);
472 if (err)
473 goto out;
474 return 0;
475 out:
476 destroy_inodecache();
477 out1:
478 return err;
479 }
480
exit_bfs_fs(void)481 static void __exit exit_bfs_fs(void)
482 {
483 unregister_filesystem(&bfs_fs_type);
484 destroy_inodecache();
485 }
486
487 module_init(init_bfs_fs)
488 module_exit(exit_bfs_fs)
489