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->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
86 inode->i_atime.tv_nsec = 0;
87 inode->i_mtime.tv_nsec = 0;
88 inode->i_ctime.tv_nsec = 0;
89
90 brelse(bh);
91 unlock_new_inode(inode);
92 return inode;
93
94 error:
95 iget_failed(inode);
96 return ERR_PTR(-EIO);
97 }
98
find_inode(struct super_block * sb,u16 ino,struct buffer_head ** p)99 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
100 {
101 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
102 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
103 return ERR_PTR(-EIO);
104 }
105
106 ino -= BFS_ROOT_INO;
107
108 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
109 if (!*p) {
110 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
111 return ERR_PTR(-EIO);
112 }
113
114 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
115 }
116
bfs_write_inode(struct inode * inode,struct writeback_control * wbc)117 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
118 {
119 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
120 unsigned int ino = (u16)inode->i_ino;
121 unsigned long i_sblock;
122 struct bfs_inode *di;
123 struct buffer_head *bh;
124 int err = 0;
125
126 dprintf("ino=%08x\n", ino);
127
128 di = find_inode(inode->i_sb, ino, &bh);
129 if (IS_ERR(di))
130 return PTR_ERR(di);
131
132 mutex_lock(&info->bfs_lock);
133
134 if (ino == BFS_ROOT_INO)
135 di->i_vtype = cpu_to_le32(BFS_VDIR);
136 else
137 di->i_vtype = cpu_to_le32(BFS_VREG);
138
139 di->i_ino = cpu_to_le16(ino);
140 di->i_mode = cpu_to_le32(inode->i_mode);
141 di->i_uid = cpu_to_le32(i_uid_read(inode));
142 di->i_gid = cpu_to_le32(i_gid_read(inode));
143 di->i_nlink = cpu_to_le32(inode->i_nlink);
144 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
145 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
146 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
147 i_sblock = BFS_I(inode)->i_sblock;
148 di->i_sblock = cpu_to_le32(i_sblock);
149 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
150 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
151
152 mark_buffer_dirty(bh);
153 if (wbc->sync_mode == WB_SYNC_ALL) {
154 sync_dirty_buffer(bh);
155 if (buffer_req(bh) && !buffer_uptodate(bh))
156 err = -EIO;
157 }
158 brelse(bh);
159 mutex_unlock(&info->bfs_lock);
160 return err;
161 }
162
bfs_evict_inode(struct inode * inode)163 static void bfs_evict_inode(struct inode *inode)
164 {
165 unsigned long ino = inode->i_ino;
166 struct bfs_inode *di;
167 struct buffer_head *bh;
168 struct super_block *s = inode->i_sb;
169 struct bfs_sb_info *info = BFS_SB(s);
170 struct bfs_inode_info *bi = BFS_I(inode);
171
172 dprintf("ino=%08lx\n", ino);
173
174 truncate_inode_pages_final(&inode->i_data);
175 invalidate_inode_buffers(inode);
176 clear_inode(inode);
177
178 if (inode->i_nlink)
179 return;
180
181 di = find_inode(s, inode->i_ino, &bh);
182 if (IS_ERR(di))
183 return;
184
185 mutex_lock(&info->bfs_lock);
186 /* clear on-disk inode */
187 memset(di, 0, sizeof(struct bfs_inode));
188 mark_buffer_dirty(bh);
189 brelse(bh);
190
191 if (bi->i_dsk_ino) {
192 if (bi->i_sblock)
193 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
194 info->si_freei++;
195 clear_bit(ino, info->si_imap);
196 bfs_dump_imap("evict_inode", s);
197 }
198
199 /*
200 * If this was the last file, make the previous block
201 * "last block of the last file" even if there is no
202 * real file there, saves us 1 gap.
203 */
204 if (info->si_lf_eblk == bi->i_eblock)
205 info->si_lf_eblk = bi->i_sblock - 1;
206 mutex_unlock(&info->bfs_lock);
207 }
208
bfs_put_super(struct super_block * s)209 static void bfs_put_super(struct super_block *s)
210 {
211 struct bfs_sb_info *info = BFS_SB(s);
212
213 if (!info)
214 return;
215
216 mutex_destroy(&info->bfs_lock);
217 kfree(info);
218 s->s_fs_info = NULL;
219 }
220
bfs_statfs(struct dentry * dentry,struct kstatfs * buf)221 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
222 {
223 struct super_block *s = dentry->d_sb;
224 struct bfs_sb_info *info = BFS_SB(s);
225 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
226 buf->f_type = BFS_MAGIC;
227 buf->f_bsize = s->s_blocksize;
228 buf->f_blocks = info->si_blocks;
229 buf->f_bfree = buf->f_bavail = info->si_freeb;
230 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
231 buf->f_ffree = info->si_freei;
232 buf->f_fsid.val[0] = (u32)id;
233 buf->f_fsid.val[1] = (u32)(id >> 32);
234 buf->f_namelen = BFS_NAMELEN;
235 return 0;
236 }
237
238 static struct kmem_cache *bfs_inode_cachep;
239
bfs_alloc_inode(struct super_block * sb)240 static struct inode *bfs_alloc_inode(struct super_block *sb)
241 {
242 struct bfs_inode_info *bi;
243 bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
244 if (!bi)
245 return NULL;
246 return &bi->vfs_inode;
247 }
248
bfs_free_inode(struct inode * inode)249 static void bfs_free_inode(struct inode *inode)
250 {
251 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
252 }
253
init_once(void * foo)254 static void init_once(void *foo)
255 {
256 struct bfs_inode_info *bi = foo;
257
258 inode_init_once(&bi->vfs_inode);
259 }
260
init_inodecache(void)261 static int __init init_inodecache(void)
262 {
263 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
264 sizeof(struct bfs_inode_info),
265 0, (SLAB_RECLAIM_ACCOUNT|
266 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
267 init_once);
268 if (bfs_inode_cachep == NULL)
269 return -ENOMEM;
270 return 0;
271 }
272
destroy_inodecache(void)273 static void destroy_inodecache(void)
274 {
275 /*
276 * Make sure all delayed rcu free inodes are flushed before we
277 * destroy cache.
278 */
279 rcu_barrier();
280 kmem_cache_destroy(bfs_inode_cachep);
281 }
282
283 static const struct super_operations bfs_sops = {
284 .alloc_inode = bfs_alloc_inode,
285 .free_inode = bfs_free_inode,
286 .write_inode = bfs_write_inode,
287 .evict_inode = bfs_evict_inode,
288 .put_super = bfs_put_super,
289 .statfs = bfs_statfs,
290 };
291
bfs_dump_imap(const char * prefix,struct super_block * s)292 void bfs_dump_imap(const char *prefix, struct super_block *s)
293 {
294 #ifdef DEBUG
295 int i;
296 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
297
298 if (!tmpbuf)
299 return;
300 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
301 if (i > PAGE_SIZE - 100) break;
302 if (test_bit(i, BFS_SB(s)->si_imap))
303 strcat(tmpbuf, "1");
304 else
305 strcat(tmpbuf, "0");
306 }
307 printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
308 free_page((unsigned long)tmpbuf);
309 #endif
310 }
311
bfs_fill_super(struct super_block * s,void * data,int silent)312 static int bfs_fill_super(struct super_block *s, void *data, int silent)
313 {
314 struct buffer_head *bh, *sbh;
315 struct bfs_super_block *bfs_sb;
316 struct inode *inode;
317 unsigned i;
318 struct bfs_sb_info *info;
319 int ret = -EINVAL;
320 unsigned long i_sblock, i_eblock, i_eoff, s_size;
321
322 info = kzalloc(sizeof(*info), GFP_KERNEL);
323 if (!info)
324 return -ENOMEM;
325 mutex_init(&info->bfs_lock);
326 s->s_fs_info = info;
327 s->s_time_min = 0;
328 s->s_time_max = U32_MAX;
329
330 sb_set_blocksize(s, BFS_BSIZE);
331
332 sbh = sb_bread(s, 0);
333 if (!sbh)
334 goto out;
335 bfs_sb = (struct bfs_super_block *)sbh->b_data;
336 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
337 if (!silent)
338 printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id, le32_to_cpu(bfs_sb->s_magic));
339 goto out1;
340 }
341 if (BFS_UNCLEAN(bfs_sb, s) && !silent)
342 printf("%s is unclean, continuing\n", s->s_id);
343
344 s->s_magic = BFS_MAGIC;
345
346 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
347 le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
348 printf("Superblock is corrupted on %s\n", s->s_id);
349 goto out1;
350 }
351
352 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
353 if (info->si_lasti == BFS_MAX_LASTI)
354 printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
355 else if (info->si_lasti > BFS_MAX_LASTI) {
356 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
357 goto out1;
358 }
359 for (i = 0; i < BFS_ROOT_INO; i++)
360 set_bit(i, info->si_imap);
361
362 s->s_op = &bfs_sops;
363 inode = bfs_iget(s, BFS_ROOT_INO);
364 if (IS_ERR(inode)) {
365 ret = PTR_ERR(inode);
366 goto out1;
367 }
368 s->s_root = d_make_root(inode);
369 if (!s->s_root) {
370 ret = -ENOMEM;
371 goto out1;
372 }
373
374 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
375 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
376 info->si_freei = 0;
377 info->si_lf_eblk = 0;
378
379 /* can we read the last block? */
380 bh = sb_bread(s, info->si_blocks - 1);
381 if (!bh) {
382 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
383 ret = -EIO;
384 goto out2;
385 }
386 brelse(bh);
387
388 bh = NULL;
389 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
390 struct bfs_inode *di;
391 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
392 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
393 unsigned long eblock;
394
395 if (!off) {
396 brelse(bh);
397 bh = sb_bread(s, block);
398 }
399
400 if (!bh)
401 continue;
402
403 di = (struct bfs_inode *)bh->b_data + off;
404
405 /* test if filesystem is not corrupted */
406
407 i_eoff = le32_to_cpu(di->i_eoffset);
408 i_sblock = le32_to_cpu(di->i_sblock);
409 i_eblock = le32_to_cpu(di->i_eblock);
410 s_size = le32_to_cpu(bfs_sb->s_end);
411
412 if (i_sblock > info->si_blocks ||
413 i_eblock > info->si_blocks ||
414 i_sblock > i_eblock ||
415 (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
416 i_sblock * BFS_BSIZE > i_eoff) {
417
418 printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
419
420 brelse(bh);
421 ret = -EIO;
422 goto out2;
423 }
424
425 if (!di->i_ino) {
426 info->si_freei++;
427 continue;
428 }
429 set_bit(i, info->si_imap);
430 info->si_freeb -= BFS_FILEBLOCKS(di);
431
432 eblock = le32_to_cpu(di->i_eblock);
433 if (eblock > info->si_lf_eblk)
434 info->si_lf_eblk = eblock;
435 }
436 brelse(bh);
437 brelse(sbh);
438 bfs_dump_imap("fill_super", s);
439 return 0;
440
441 out2:
442 dput(s->s_root);
443 s->s_root = NULL;
444 out1:
445 brelse(sbh);
446 out:
447 mutex_destroy(&info->bfs_lock);
448 kfree(info);
449 s->s_fs_info = NULL;
450 return ret;
451 }
452
bfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)453 static struct dentry *bfs_mount(struct file_system_type *fs_type,
454 int flags, const char *dev_name, void *data)
455 {
456 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
457 }
458
459 static struct file_system_type bfs_fs_type = {
460 .owner = THIS_MODULE,
461 .name = "bfs",
462 .mount = bfs_mount,
463 .kill_sb = kill_block_super,
464 .fs_flags = FS_REQUIRES_DEV,
465 };
466 MODULE_ALIAS_FS("bfs");
467
init_bfs_fs(void)468 static int __init init_bfs_fs(void)
469 {
470 int err = init_inodecache();
471 if (err)
472 goto out1;
473 err = register_filesystem(&bfs_fs_type);
474 if (err)
475 goto out;
476 return 0;
477 out:
478 destroy_inodecache();
479 out1:
480 return err;
481 }
482
exit_bfs_fs(void)483 static void __exit exit_bfs_fs(void)
484 {
485 unregister_filesystem(&bfs_fs_type);
486 destroy_inodecache();
487 }
488
489 module_init(init_bfs_fs)
490 module_exit(exit_bfs_fs)
491