1 /*
2 * fs/bfs/inode.c
3 * BFS superblock and inode operations.
4 * Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5 * From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
6 *
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 <asm/uaccess.h>
19 #include "bfs.h"
20
21 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
22 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
23 MODULE_LICENSE("GPL");
24
25 #undef DEBUG
26
27 #ifdef DEBUG
28 #define dprintf(x...) printf(x)
29 #else
30 #define dprintf(x...)
31 #endif
32
33 void dump_imap(const char *prefix, struct super_block *s);
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 (IS_ERR(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 inode->i_uid = le32_to_cpu(di->i_uid);
80 inode->i_gid = le32_to_cpu(di->i_gid);
81 inode->i_nlink = le32_to_cpu(di->i_nlink);
82 inode->i_size = BFS_FILESIZE(di);
83 inode->i_blocks = BFS_FILEBLOCKS(di);
84 inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
85 inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
86 inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
87 inode->i_atime.tv_nsec = 0;
88 inode->i_mtime.tv_nsec = 0;
89 inode->i_ctime.tv_nsec = 0;
90
91 brelse(bh);
92 unlock_new_inode(inode);
93 return inode;
94
95 error:
96 iget_failed(inode);
97 return ERR_PTR(-EIO);
98 }
99
find_inode(struct super_block * sb,u16 ino,struct buffer_head ** p)100 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
101 {
102 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
103 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
104 return ERR_PTR(-EIO);
105 }
106
107 ino -= BFS_ROOT_INO;
108
109 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
110 if (!*p) {
111 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
112 return ERR_PTR(-EIO);
113 }
114
115 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
116 }
117
bfs_write_inode(struct inode * inode,struct writeback_control * wbc)118 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
119 {
120 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
121 unsigned int ino = (u16)inode->i_ino;
122 unsigned long i_sblock;
123 struct bfs_inode *di;
124 struct buffer_head *bh;
125 int err = 0;
126
127 dprintf("ino=%08x\n", ino);
128
129 di = find_inode(inode->i_sb, ino, &bh);
130 if (IS_ERR(di))
131 return PTR_ERR(di);
132
133 mutex_lock(&info->bfs_lock);
134
135 if (ino == BFS_ROOT_INO)
136 di->i_vtype = cpu_to_le32(BFS_VDIR);
137 else
138 di->i_vtype = cpu_to_le32(BFS_VREG);
139
140 di->i_ino = cpu_to_le16(ino);
141 di->i_mode = cpu_to_le32(inode->i_mode);
142 di->i_uid = cpu_to_le32(inode->i_uid);
143 di->i_gid = cpu_to_le32(inode->i_gid);
144 di->i_nlink = cpu_to_le32(inode->i_nlink);
145 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
146 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
147 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
148 i_sblock = BFS_I(inode)->i_sblock;
149 di->i_sblock = cpu_to_le32(i_sblock);
150 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
151 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
152
153 mark_buffer_dirty(bh);
154 if (wbc->sync_mode == WB_SYNC_ALL) {
155 sync_dirty_buffer(bh);
156 if (buffer_req(bh) && !buffer_uptodate(bh))
157 err = -EIO;
158 }
159 brelse(bh);
160 mutex_unlock(&info->bfs_lock);
161 return err;
162 }
163
bfs_evict_inode(struct inode * inode)164 static void bfs_evict_inode(struct inode *inode)
165 {
166 unsigned long ino = inode->i_ino;
167 struct bfs_inode *di;
168 struct buffer_head *bh;
169 struct super_block *s = inode->i_sb;
170 struct bfs_sb_info *info = BFS_SB(s);
171 struct bfs_inode_info *bi = BFS_I(inode);
172
173 dprintf("ino=%08lx\n", ino);
174
175 truncate_inode_pages(&inode->i_data, 0);
176 invalidate_inode_buffers(inode);
177 end_writeback(inode);
178
179 if (inode->i_nlink)
180 return;
181
182 di = find_inode(s, inode->i_ino, &bh);
183 if (IS_ERR(di))
184 return;
185
186 mutex_lock(&info->bfs_lock);
187 /* clear on-disk inode */
188 memset(di, 0, sizeof(struct bfs_inode));
189 mark_buffer_dirty(bh);
190 brelse(bh);
191
192 if (bi->i_dsk_ino) {
193 if (bi->i_sblock)
194 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
195 info->si_freei++;
196 clear_bit(ino, info->si_imap);
197 dump_imap("delete_inode", s);
198 }
199
200 /*
201 * If this was the last file, make the previous block
202 * "last block of the last file" even if there is no
203 * real file there, saves us 1 gap.
204 */
205 if (info->si_lf_eblk == bi->i_eblock)
206 info->si_lf_eblk = bi->i_sblock - 1;
207 mutex_unlock(&info->bfs_lock);
208 }
209
bfs_put_super(struct super_block * s)210 static void bfs_put_super(struct super_block *s)
211 {
212 struct bfs_sb_info *info = BFS_SB(s);
213
214 if (!info)
215 return;
216
217 mutex_destroy(&info->bfs_lock);
218 kfree(info->si_imap);
219 kfree(info);
220 s->s_fs_info = NULL;
221 }
222
bfs_statfs(struct dentry * dentry,struct kstatfs * buf)223 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
224 {
225 struct super_block *s = dentry->d_sb;
226 struct bfs_sb_info *info = BFS_SB(s);
227 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
228 buf->f_type = BFS_MAGIC;
229 buf->f_bsize = s->s_blocksize;
230 buf->f_blocks = info->si_blocks;
231 buf->f_bfree = buf->f_bavail = info->si_freeb;
232 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
233 buf->f_ffree = info->si_freei;
234 buf->f_fsid.val[0] = (u32)id;
235 buf->f_fsid.val[1] = (u32)(id >> 32);
236 buf->f_namelen = BFS_NAMELEN;
237 return 0;
238 }
239
240 static struct kmem_cache *bfs_inode_cachep;
241
bfs_alloc_inode(struct super_block * sb)242 static struct inode *bfs_alloc_inode(struct super_block *sb)
243 {
244 struct bfs_inode_info *bi;
245 bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
246 if (!bi)
247 return NULL;
248 return &bi->vfs_inode;
249 }
250
bfs_i_callback(struct rcu_head * head)251 static void bfs_i_callback(struct rcu_head *head)
252 {
253 struct inode *inode = container_of(head, struct inode, i_rcu);
254 INIT_LIST_HEAD(&inode->i_dentry);
255 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
256 }
257
bfs_destroy_inode(struct inode * inode)258 static void bfs_destroy_inode(struct inode *inode)
259 {
260 call_rcu(&inode->i_rcu, bfs_i_callback);
261 }
262
init_once(void * foo)263 static void init_once(void *foo)
264 {
265 struct bfs_inode_info *bi = foo;
266
267 inode_init_once(&bi->vfs_inode);
268 }
269
init_inodecache(void)270 static int init_inodecache(void)
271 {
272 bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
273 sizeof(struct bfs_inode_info),
274 0, (SLAB_RECLAIM_ACCOUNT|
275 SLAB_MEM_SPREAD),
276 init_once);
277 if (bfs_inode_cachep == NULL)
278 return -ENOMEM;
279 return 0;
280 }
281
destroy_inodecache(void)282 static void destroy_inodecache(void)
283 {
284 kmem_cache_destroy(bfs_inode_cachep);
285 }
286
287 static const struct super_operations bfs_sops = {
288 .alloc_inode = bfs_alloc_inode,
289 .destroy_inode = bfs_destroy_inode,
290 .write_inode = bfs_write_inode,
291 .evict_inode = bfs_evict_inode,
292 .put_super = bfs_put_super,
293 .statfs = bfs_statfs,
294 };
295
dump_imap(const char * prefix,struct super_block * s)296 void dump_imap(const char *prefix, struct super_block *s)
297 {
298 #ifdef DEBUG
299 int i;
300 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
301
302 if (!tmpbuf)
303 return;
304 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
305 if (i > PAGE_SIZE - 100) break;
306 if (test_bit(i, BFS_SB(s)->si_imap))
307 strcat(tmpbuf, "1");
308 else
309 strcat(tmpbuf, "0");
310 }
311 printf("BFS-fs: %s: lasti=%08lx <%s>\n",
312 prefix, BFS_SB(s)->si_lasti, tmpbuf);
313 free_page((unsigned long)tmpbuf);
314 #endif
315 }
316
bfs_fill_super(struct super_block * s,void * data,int silent)317 static int bfs_fill_super(struct super_block *s, void *data, int silent)
318 {
319 struct buffer_head *bh, *sbh;
320 struct bfs_super_block *bfs_sb;
321 struct inode *inode;
322 unsigned i, imap_len;
323 struct bfs_sb_info *info;
324 int ret = -EINVAL;
325 unsigned long i_sblock, i_eblock, i_eoff, s_size;
326
327 info = kzalloc(sizeof(*info), GFP_KERNEL);
328 if (!info)
329 return -ENOMEM;
330 mutex_init(&info->bfs_lock);
331 s->s_fs_info = info;
332
333 sb_set_blocksize(s, BFS_BSIZE);
334
335 sbh = sb_bread(s, 0);
336 if (!sbh)
337 goto out;
338 bfs_sb = (struct bfs_super_block *)sbh->b_data;
339 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
340 if (!silent)
341 printf("No BFS filesystem on %s (magic=%08x)\n",
342 s->s_id, le32_to_cpu(bfs_sb->s_magic));
343 goto out1;
344 }
345 if (BFS_UNCLEAN(bfs_sb, s) && !silent)
346 printf("%s is unclean, continuing\n", s->s_id);
347
348 s->s_magic = BFS_MAGIC;
349
350 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
351 printf("Superblock is corrupted\n");
352 goto out1;
353 }
354
355 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
356 sizeof(struct bfs_inode)
357 + BFS_ROOT_INO - 1;
358 imap_len = (info->si_lasti / 8) + 1;
359 info->si_imap = kzalloc(imap_len, GFP_KERNEL);
360 if (!info->si_imap)
361 goto out1;
362 for (i = 0; i < BFS_ROOT_INO; i++)
363 set_bit(i, info->si_imap);
364
365 s->s_op = &bfs_sops;
366 inode = bfs_iget(s, BFS_ROOT_INO);
367 if (IS_ERR(inode)) {
368 ret = PTR_ERR(inode);
369 goto out2;
370 }
371 s->s_root = d_alloc_root(inode);
372 if (!s->s_root) {
373 iput(inode);
374 ret = -ENOMEM;
375 goto out2;
376 }
377
378 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
379 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
380 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
381 info->si_freei = 0;
382 info->si_lf_eblk = 0;
383
384 /* can we read the last block? */
385 bh = sb_bread(s, info->si_blocks - 1);
386 if (!bh) {
387 printf("Last block not available: %lu\n", info->si_blocks - 1);
388 ret = -EIO;
389 goto out3;
390 }
391 brelse(bh);
392
393 bh = NULL;
394 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
395 struct bfs_inode *di;
396 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
397 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
398 unsigned long eblock;
399
400 if (!off) {
401 brelse(bh);
402 bh = sb_bread(s, block);
403 }
404
405 if (!bh)
406 continue;
407
408 di = (struct bfs_inode *)bh->b_data + off;
409
410 /* test if filesystem is not corrupted */
411
412 i_eoff = le32_to_cpu(di->i_eoffset);
413 i_sblock = le32_to_cpu(di->i_sblock);
414 i_eblock = le32_to_cpu(di->i_eblock);
415 s_size = le32_to_cpu(bfs_sb->s_end);
416
417 if (i_sblock > info->si_blocks ||
418 i_eblock > info->si_blocks ||
419 i_sblock > i_eblock ||
420 i_eoff > s_size ||
421 i_sblock * BFS_BSIZE > i_eoff) {
422
423 printf("Inode 0x%08x corrupted\n", i);
424
425 brelse(bh);
426 ret = -EIO;
427 goto out3;
428 }
429
430 if (!di->i_ino) {
431 info->si_freei++;
432 continue;
433 }
434 set_bit(i, info->si_imap);
435 info->si_freeb -= BFS_FILEBLOCKS(di);
436
437 eblock = le32_to_cpu(di->i_eblock);
438 if (eblock > info->si_lf_eblk)
439 info->si_lf_eblk = eblock;
440 }
441 brelse(bh);
442 brelse(sbh);
443 dump_imap("read_super", s);
444 return 0;
445
446 out3:
447 dput(s->s_root);
448 s->s_root = NULL;
449 out2:
450 kfree(info->si_imap);
451 out1:
452 brelse(sbh);
453 out:
454 mutex_destroy(&info->bfs_lock);
455 kfree(info);
456 s->s_fs_info = NULL;
457 return ret;
458 }
459
bfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)460 static struct dentry *bfs_mount(struct file_system_type *fs_type,
461 int flags, const char *dev_name, void *data)
462 {
463 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
464 }
465
466 static struct file_system_type bfs_fs_type = {
467 .owner = THIS_MODULE,
468 .name = "bfs",
469 .mount = bfs_mount,
470 .kill_sb = kill_block_super,
471 .fs_flags = FS_REQUIRES_DEV,
472 };
473
init_bfs_fs(void)474 static int __init init_bfs_fs(void)
475 {
476 int err = init_inodecache();
477 if (err)
478 goto out1;
479 err = register_filesystem(&bfs_fs_type);
480 if (err)
481 goto out;
482 return 0;
483 out:
484 destroy_inodecache();
485 out1:
486 return err;
487 }
488
exit_bfs_fs(void)489 static void __exit exit_bfs_fs(void)
490 {
491 unregister_filesystem(&bfs_fs_type);
492 destroy_inodecache();
493 }
494
495 module_init(init_bfs_fs)
496 module_exit(exit_bfs_fs)
497