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_set_atime(inode, le32_to_cpu(di->i_atime), 0);
84 inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0);
85 inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);
86
87 brelse(bh);
88 unlock_new_inode(inode);
89 return inode;
90
91 error:
92 iget_failed(inode);
93 return ERR_PTR(-EIO);
94 }
95
find_inode(struct super_block * sb,u16 ino,struct buffer_head ** p)96 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
97 {
98 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
99 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
100 return ERR_PTR(-EIO);
101 }
102
103 ino -= BFS_ROOT_INO;
104
105 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
106 if (!*p) {
107 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
108 return ERR_PTR(-EIO);
109 }
110
111 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
112 }
113
bfs_write_inode(struct inode * inode,struct writeback_control * wbc)114 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
115 {
116 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
117 unsigned int ino = (u16)inode->i_ino;
118 unsigned long i_sblock;
119 struct bfs_inode *di;
120 struct buffer_head *bh;
121 int err = 0;
122
123 dprintf("ino=%08x\n", ino);
124
125 di = find_inode(inode->i_sb, ino, &bh);
126 if (IS_ERR(di))
127 return PTR_ERR(di);
128
129 mutex_lock(&info->bfs_lock);
130
131 if (ino == BFS_ROOT_INO)
132 di->i_vtype = cpu_to_le32(BFS_VDIR);
133 else
134 di->i_vtype = cpu_to_le32(BFS_VREG);
135
136 di->i_ino = cpu_to_le16(ino);
137 di->i_mode = cpu_to_le32(inode->i_mode);
138 di->i_uid = cpu_to_le32(i_uid_read(inode));
139 di->i_gid = cpu_to_le32(i_gid_read(inode));
140 di->i_nlink = cpu_to_le32(inode->i_nlink);
141 di->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
142 di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
143 di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
144 i_sblock = BFS_I(inode)->i_sblock;
145 di->i_sblock = cpu_to_le32(i_sblock);
146 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
147 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
148
149 mark_buffer_dirty(bh);
150 if (wbc->sync_mode == WB_SYNC_ALL) {
151 sync_dirty_buffer(bh);
152 if (buffer_req(bh) && !buffer_uptodate(bh))
153 err = -EIO;
154 }
155 brelse(bh);
156 mutex_unlock(&info->bfs_lock);
157 return err;
158 }
159
bfs_evict_inode(struct inode * inode)160 static void bfs_evict_inode(struct inode *inode)
161 {
162 unsigned long ino = inode->i_ino;
163 struct bfs_inode *di;
164 struct buffer_head *bh;
165 struct super_block *s = inode->i_sb;
166 struct bfs_sb_info *info = BFS_SB(s);
167 struct bfs_inode_info *bi = BFS_I(inode);
168
169 dprintf("ino=%08lx\n", ino);
170
171 truncate_inode_pages_final(&inode->i_data);
172 invalidate_inode_buffers(inode);
173 clear_inode(inode);
174
175 if (inode->i_nlink)
176 return;
177
178 di = find_inode(s, inode->i_ino, &bh);
179 if (IS_ERR(di))
180 return;
181
182 mutex_lock(&info->bfs_lock);
183 /* clear on-disk inode */
184 memset(di, 0, sizeof(struct bfs_inode));
185 mark_buffer_dirty(bh);
186 brelse(bh);
187
188 if (bi->i_dsk_ino) {
189 if (bi->i_sblock)
190 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
191 info->si_freei++;
192 clear_bit(ino, info->si_imap);
193 bfs_dump_imap("evict_inode", s);
194 }
195
196 /*
197 * If this was the last file, make the previous block
198 * "last block of the last file" even if there is no
199 * real file there, saves us 1 gap.
200 */
201 if (info->si_lf_eblk == bi->i_eblock)
202 info->si_lf_eblk = bi->i_sblock - 1;
203 mutex_unlock(&info->bfs_lock);
204 }
205
bfs_put_super(struct super_block * s)206 static void bfs_put_super(struct super_block *s)
207 {
208 struct bfs_sb_info *info = BFS_SB(s);
209
210 if (!info)
211 return;
212
213 mutex_destroy(&info->bfs_lock);
214 kfree(info);
215 s->s_fs_info = NULL;
216 }
217
bfs_statfs(struct dentry * dentry,struct kstatfs * buf)218 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
219 {
220 struct super_block *s = dentry->d_sb;
221 struct bfs_sb_info *info = BFS_SB(s);
222 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
223 buf->f_type = BFS_MAGIC;
224 buf->f_bsize = s->s_blocksize;
225 buf->f_blocks = info->si_blocks;
226 buf->f_bfree = buf->f_bavail = info->si_freeb;
227 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
228 buf->f_ffree = info->si_freei;
229 buf->f_fsid = u64_to_fsid(id);
230 buf->f_namelen = BFS_NAMELEN;
231 return 0;
232 }
233
234 static struct kmem_cache *bfs_inode_cachep;
235
bfs_alloc_inode(struct super_block * sb)236 static struct inode *bfs_alloc_inode(struct super_block *sb)
237 {
238 struct bfs_inode_info *bi;
239 bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
240 if (!bi)
241 return NULL;
242 return &bi->vfs_inode;
243 }
244
bfs_free_inode(struct inode * inode)245 static void bfs_free_inode(struct inode *inode)
246 {
247 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
248 }
249
init_once(void * foo)250 static void init_once(void *foo)
251 {
252 struct bfs_inode_info *bi = foo;
253
254 inode_init_once(&bi->vfs_inode);
255 }
256
init_inodecache(void)257 static int __init init_inodecache(void)
258 {
259 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
260 sizeof(struct bfs_inode_info),
261 0, (SLAB_RECLAIM_ACCOUNT|
262 SLAB_ACCOUNT),
263 init_once);
264 if (bfs_inode_cachep == NULL)
265 return -ENOMEM;
266 return 0;
267 }
268
destroy_inodecache(void)269 static void destroy_inodecache(void)
270 {
271 /*
272 * Make sure all delayed rcu free inodes are flushed before we
273 * destroy cache.
274 */
275 rcu_barrier();
276 kmem_cache_destroy(bfs_inode_cachep);
277 }
278
279 static const struct super_operations bfs_sops = {
280 .alloc_inode = bfs_alloc_inode,
281 .free_inode = bfs_free_inode,
282 .write_inode = bfs_write_inode,
283 .evict_inode = bfs_evict_inode,
284 .put_super = bfs_put_super,
285 .statfs = bfs_statfs,
286 };
287
bfs_dump_imap(const char * prefix,struct super_block * s)288 void bfs_dump_imap(const char *prefix, struct super_block *s)
289 {
290 #ifdef DEBUG
291 int i;
292 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
293
294 if (!tmpbuf)
295 return;
296 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
297 if (i > PAGE_SIZE - 100) break;
298 if (test_bit(i, BFS_SB(s)->si_imap))
299 strcat(tmpbuf, "1");
300 else
301 strcat(tmpbuf, "0");
302 }
303 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
304 free_page((unsigned long)tmpbuf);
305 #endif
306 }
307
bfs_fill_super(struct super_block * s,void * data,int silent)308 static int bfs_fill_super(struct super_block *s, void *data, int silent)
309 {
310 struct buffer_head *bh, *sbh;
311 struct bfs_super_block *bfs_sb;
312 struct inode *inode;
313 unsigned i;
314 struct bfs_sb_info *info;
315 int ret = -EINVAL;
316 unsigned long i_sblock, i_eblock, i_eoff, s_size;
317
318 info = kzalloc(sizeof(*info), GFP_KERNEL);
319 if (!info)
320 return -ENOMEM;
321 mutex_init(&info->bfs_lock);
322 s->s_fs_info = info;
323 s->s_time_min = 0;
324 s->s_time_max = U32_MAX;
325
326 sb_set_blocksize(s, BFS_BSIZE);
327
328 sbh = sb_bread(s, 0);
329 if (!sbh)
330 goto out;
331 bfs_sb = (struct bfs_super_block *)sbh->b_data;
332 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
333 if (!silent)
334 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic));
335 goto out1;
336 }
337 if (BFS_UNCLEAN(bfs_sb, s) && !silent)
338 printf("%s is unclean, continuing\n", s->s_id);
339
340 s->s_magic = BFS_MAGIC;
341
342 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
343 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
344 printf("Superblock is corrupted on %s\n", s->s_id);
345 goto out1;
346 }
347
348 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
349 if (info->si_lasti == BFS_MAX_LASTI)
350 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
351 else if (info->si_lasti > BFS_MAX_LASTI) {
352 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
353 goto out1;
354 }
355 for (i = 0; i < BFS_ROOT_INO; i++)
356 set_bit(i, info->si_imap);
357
358 s->s_op = &bfs_sops;
359 inode = bfs_iget(s, BFS_ROOT_INO);
360 if (IS_ERR(inode)) {
361 ret = PTR_ERR(inode);
362 goto out1;
363 }
364 s->s_root = d_make_root(inode);
365 if (!s->s_root) {
366 ret = -ENOMEM;
367 goto out1;
368 }
369
370 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
371 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
372 info->si_freei = 0;
373 info->si_lf_eblk = 0;
374
375 /* can we read the last block? */
376 bh = sb_bread(s, info->si_blocks - 1);
377 if (!bh) {
378 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
379 ret = -EIO;
380 goto out2;
381 }
382 brelse(bh);
383
384 bh = NULL;
385 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
386 struct bfs_inode *di;
387 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
388 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
389 unsigned long eblock;
390
391 if (!off) {
392 brelse(bh);
393 bh = sb_bread(s, block);
394 }
395
396 if (!bh)
397 continue;
398
399 di = (struct bfs_inode *)bh->b_data + off;
400
401 /* test if filesystem is not corrupted */
402
403 i_eoff = le32_to_cpu(di->i_eoffset);
404 i_sblock = le32_to_cpu(di->i_sblock);
405 i_eblock = le32_to_cpu(di->i_eblock);
406 s_size = le32_to_cpu(bfs_sb->s_end);
407
408 if (i_sblock > info->si_blocks ||
409 i_eblock > info->si_blocks ||
410 i_sblock > i_eblock ||
411 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
412 i_sblock * BFS_BSIZE > i_eoff) {
413
414 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
415
416 brelse(bh);
417 ret = -EIO;
418 goto out2;
419 }
420
421 if (!di->i_ino) {
422 info->si_freei++;
423 continue;
424 }
425 set_bit(i, info->si_imap);
426 info->si_freeb -= BFS_FILEBLOCKS(di);
427
428 eblock = le32_to_cpu(di->i_eblock);
429 if (eblock > info->si_lf_eblk)
430 info->si_lf_eblk = eblock;
431 }
432 brelse(bh);
433 brelse(sbh);
434 bfs_dump_imap("fill_super", s);
435 return 0;
436
437 out2:
438 dput(s->s_root);
439 s->s_root = NULL;
440 out1:
441 brelse(sbh);
442 out:
443 mutex_destroy(&info->bfs_lock);
444 kfree(info);
445 s->s_fs_info = NULL;
446 return ret;
447 }
448
bfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)449 static struct dentry *bfs_mount(struct file_system_type *fs_type,
450 int flags, const char *dev_name, void *data)
451 {
452 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
453 }
454
455 static struct file_system_type bfs_fs_type = {
456 .owner = THIS_MODULE,
457 .name = "bfs",
458 .mount = bfs_mount,
459 .kill_sb = kill_block_super,
460 .fs_flags = FS_REQUIRES_DEV,
461 };
462 MODULE_ALIAS_FS("bfs");
463
init_bfs_fs(void)464 static int __init init_bfs_fs(void)
465 {
466 int err = init_inodecache();
467 if (err)
468 goto out1;
469 err = register_filesystem(&bfs_fs_type);
470 if (err)
471 goto out;
472 return 0;
473 out:
474 destroy_inodecache();
475 out1:
476 return err;
477 }
478
exit_bfs_fs(void)479 static void __exit exit_bfs_fs(void)
480 {
481 unregister_filesystem(&bfs_fs_type);
482 destroy_inodecache();
483 }
484
485 module_init(init_bfs_fs)
486 module_exit(exit_bfs_fs)
487