d136b2aaafb3a931922d912a4f836ef6536a3352
[muen/linux.git] / fs / bfs / inode.c
1 /*
2  *      fs/bfs/inode.c
3  *      BFS superblock and inode operations.
4  *      Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
6  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
7  */
8
9 #include <linux/module.h>
10 #include <linux/mm.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/fs.h>
14 #include <linux/buffer_head.h>
15 #include <linux/vfs.h>
16 #include <linux/writeback.h>
17 #include <linux/uio.h>
18 #include <linux/uaccess.h>
19 #include "bfs.h"
20
21 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
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 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
34 {
35         struct bfs_inode *di;
36         struct inode *inode;
37         struct buffer_head *bh;
38         int block, off;
39
40         inode = iget_locked(sb, ino);
41         if (!inode)
42                 return ERR_PTR(-ENOMEM);
43         if (!(inode->i_state & I_NEW))
44                 return inode;
45
46         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
47                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
48                 goto error;
49         }
50
51         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
52         bh = sb_bread(inode->i_sb, block);
53         if (!bh) {
54                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
55                                                                         ino);
56                 goto error;
57         }
58
59         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
60         di = (struct bfs_inode *)bh->b_data + off;
61
62         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
63         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
64                 inode->i_mode |= S_IFDIR;
65                 inode->i_op = &bfs_dir_inops;
66                 inode->i_fop = &bfs_dir_operations;
67         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
68                 inode->i_mode |= S_IFREG;
69                 inode->i_op = &bfs_file_inops;
70                 inode->i_fop = &bfs_file_operations;
71                 inode->i_mapping->a_ops = &bfs_aops;
72         }
73
74         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
75         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
76         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
77         i_uid_write(inode, le32_to_cpu(di->i_uid));
78         i_gid_write(inode,  le32_to_cpu(di->i_gid));
79         set_nlink(inode, le32_to_cpu(di->i_nlink));
80         inode->i_size = BFS_FILESIZE(di);
81         inode->i_blocks = BFS_FILEBLOCKS(di);
82         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
83         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
84         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
85         inode->i_atime.tv_nsec = 0;
86         inode->i_mtime.tv_nsec = 0;
87         inode->i_ctime.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
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
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->i_ctime.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
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
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
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.val[0] = (u32)id;
232         buf->f_fsid.val[1] = (u32)(id >> 32);
233         buf->f_namelen = BFS_NAMELEN;
234         return 0;
235 }
236
237 static struct kmem_cache *bfs_inode_cachep;
238
239 static struct inode *bfs_alloc_inode(struct super_block *sb)
240 {
241         struct bfs_inode_info *bi;
242         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
243         if (!bi)
244                 return NULL;
245         return &bi->vfs_inode;
246 }
247
248 static void bfs_i_callback(struct rcu_head *head)
249 {
250         struct inode *inode = container_of(head, struct inode, i_rcu);
251         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
252 }
253
254 static void bfs_destroy_inode(struct inode *inode)
255 {
256         call_rcu(&inode->i_rcu, bfs_i_callback);
257 }
258
259 static void init_once(void *foo)
260 {
261         struct bfs_inode_info *bi = foo;
262
263         inode_init_once(&bi->vfs_inode);
264 }
265
266 static int __init init_inodecache(void)
267 {
268         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
269                                              sizeof(struct bfs_inode_info),
270                                              0, (SLAB_RECLAIM_ACCOUNT|
271                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
272                                              init_once);
273         if (bfs_inode_cachep == NULL)
274                 return -ENOMEM;
275         return 0;
276 }
277
278 static void destroy_inodecache(void)
279 {
280         /*
281          * Make sure all delayed rcu free inodes are flushed before we
282          * destroy cache.
283          */
284         rcu_barrier();
285         kmem_cache_destroy(bfs_inode_cachep);
286 }
287
288 static const struct super_operations bfs_sops = {
289         .alloc_inode    = bfs_alloc_inode,
290         .destroy_inode  = bfs_destroy_inode,
291         .write_inode    = bfs_write_inode,
292         .evict_inode    = bfs_evict_inode,
293         .put_super      = bfs_put_super,
294         .statfs         = bfs_statfs,
295 };
296
297 void bfs_dump_imap(const char *prefix, struct super_block *s)
298 {
299 #ifdef DEBUG
300         int i;
301         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
302
303         if (!tmpbuf)
304                 return;
305         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
306                 if (i > PAGE_SIZE - 100) break;
307                 if (test_bit(i, BFS_SB(s)->si_imap))
308                         strcat(tmpbuf, "1");
309                 else
310                         strcat(tmpbuf, "0");
311         }
312         printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
313         free_page((unsigned long)tmpbuf);
314 #endif
315 }
316
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;
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", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
342                 goto out1;
343         }
344         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
345                 printf("%s is unclean, continuing\n", s->s_id);
346
347         s->s_magic = BFS_MAGIC;
348
349         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
350             le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
351                 printf("Superblock is corrupted on %s\n", s->s_id);
352                 goto out1;
353         }
354
355         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
356         if (info->si_lasti == BFS_MAX_LASTI)
357                 printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
358         else if (info->si_lasti > BFS_MAX_LASTI) {
359                 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
360                 goto out1;
361         }
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 out1;
370         }
371         s->s_root = d_make_root(inode);
372         if (!s->s_root) {
373                 ret = -ENOMEM;
374                 goto out1;
375         }
376
377         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
378         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
379         info->si_freei = 0;
380         info->si_lf_eblk = 0;
381
382         /* can we read the last block? */
383         bh = sb_bread(s, info->si_blocks - 1);
384         if (!bh) {
385                 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
386                 ret = -EIO;
387                 goto out2;
388         }
389         brelse(bh);
390
391         bh = NULL;
392         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
393                 struct bfs_inode *di;
394                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
395                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
396                 unsigned long eblock;
397
398                 if (!off) {
399                         brelse(bh);
400                         bh = sb_bread(s, block);
401                 }
402
403                 if (!bh)
404                         continue;
405
406                 di = (struct bfs_inode *)bh->b_data + off;
407
408                 /* test if filesystem is not corrupted */
409
410                 i_eoff = le32_to_cpu(di->i_eoffset);
411                 i_sblock = le32_to_cpu(di->i_sblock);
412                 i_eblock = le32_to_cpu(di->i_eblock);
413                 s_size = le32_to_cpu(bfs_sb->s_end);
414
415                 if (i_sblock > info->si_blocks ||
416                         i_eblock > info->si_blocks ||
417                         i_sblock > i_eblock ||
418                         (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
419                         i_sblock * BFS_BSIZE > i_eoff) {
420
421                         printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
422
423                         brelse(bh);
424                         ret = -EIO;
425                         goto out2;
426                 }
427
428                 if (!di->i_ino) {
429                         info->si_freei++;
430                         continue;
431                 }
432                 set_bit(i, info->si_imap);
433                 info->si_freeb -= BFS_FILEBLOCKS(di);
434
435                 eblock =  le32_to_cpu(di->i_eblock);
436                 if (eblock > info->si_lf_eblk)
437                         info->si_lf_eblk = eblock;
438         }
439         brelse(bh);
440         brelse(sbh);
441         bfs_dump_imap("fill_super", s);
442         return 0;
443
444 out2:
445         dput(s->s_root);
446         s->s_root = NULL;
447 out1:
448         brelse(sbh);
449 out:
450         mutex_destroy(&info->bfs_lock);
451         kfree(info);
452         s->s_fs_info = NULL;
453         return ret;
454 }
455
456 static struct dentry *bfs_mount(struct file_system_type *fs_type,
457         int flags, const char *dev_name, void *data)
458 {
459         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
460 }
461
462 static struct file_system_type bfs_fs_type = {
463         .owner          = THIS_MODULE,
464         .name           = "bfs",
465         .mount          = bfs_mount,
466         .kill_sb        = kill_block_super,
467         .fs_flags       = FS_REQUIRES_DEV,
468 };
469 MODULE_ALIAS_FS("bfs");
470
471 static int __init init_bfs_fs(void)
472 {
473         int err = init_inodecache();
474         if (err)
475                 goto out1;
476         err = register_filesystem(&bfs_fs_type);
477         if (err)
478                 goto out;
479         return 0;
480 out:
481         destroy_inodecache();
482 out1:
483         return err;
484 }
485
486 static void __exit exit_bfs_fs(void)
487 {
488         unregister_filesystem(&bfs_fs_type);
489         destroy_inodecache();
490 }
491
492 module_init(init_bfs_fs)
493 module_exit(exit_bfs_fs)