GNU Linux-libre 4.9.308-gnu1
[releases.git] / fs / bfs / inode.c
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 <linux/uio.h>
19 #include <asm/uaccess.h>
20 #include "bfs.h"
21
22 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
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
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
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
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
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("delete_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
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->si_imap);
218         kfree(info);
219         s->s_fs_info = NULL;
220 }
221
222 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
223 {
224         struct super_block *s = dentry->d_sb;
225         struct bfs_sb_info *info = BFS_SB(s);
226         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
227         buf->f_type = BFS_MAGIC;
228         buf->f_bsize = s->s_blocksize;
229         buf->f_blocks = info->si_blocks;
230         buf->f_bfree = buf->f_bavail = info->si_freeb;
231         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
232         buf->f_ffree = info->si_freei;
233         buf->f_fsid.val[0] = (u32)id;
234         buf->f_fsid.val[1] = (u32)(id >> 32);
235         buf->f_namelen = BFS_NAMELEN;
236         return 0;
237 }
238
239 static struct kmem_cache *bfs_inode_cachep;
240
241 static struct inode *bfs_alloc_inode(struct super_block *sb)
242 {
243         struct bfs_inode_info *bi;
244         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
245         if (!bi)
246                 return NULL;
247         return &bi->vfs_inode;
248 }
249
250 static void bfs_i_callback(struct rcu_head *head)
251 {
252         struct inode *inode = container_of(head, struct inode, i_rcu);
253         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
254 }
255
256 static void bfs_destroy_inode(struct inode *inode)
257 {
258         call_rcu(&inode->i_rcu, bfs_i_callback);
259 }
260
261 static void init_once(void *foo)
262 {
263         struct bfs_inode_info *bi = foo;
264
265         inode_init_once(&bi->vfs_inode);
266 }
267
268 static int __init init_inodecache(void)
269 {
270         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
271                                              sizeof(struct bfs_inode_info),
272                                              0, (SLAB_RECLAIM_ACCOUNT|
273                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
274                                              init_once);
275         if (bfs_inode_cachep == NULL)
276                 return -ENOMEM;
277         return 0;
278 }
279
280 static void destroy_inodecache(void)
281 {
282         /*
283          * Make sure all delayed rcu free inodes are flushed before we
284          * destroy cache.
285          */
286         rcu_barrier();
287         kmem_cache_destroy(bfs_inode_cachep);
288 }
289
290 static const struct super_operations bfs_sops = {
291         .alloc_inode    = bfs_alloc_inode,
292         .destroy_inode  = bfs_destroy_inode,
293         .write_inode    = bfs_write_inode,
294         .evict_inode    = bfs_evict_inode,
295         .put_super      = bfs_put_super,
296         .statfs         = bfs_statfs,
297 };
298
299 void bfs_dump_imap(const char *prefix, struct super_block *s)
300 {
301 #ifdef DEBUG
302         int i;
303         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
304
305         if (!tmpbuf)
306                 return;
307         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
308                 if (i > PAGE_SIZE - 100) break;
309                 if (test_bit(i, BFS_SB(s)->si_imap))
310                         strcat(tmpbuf, "1");
311                 else
312                         strcat(tmpbuf, "0");
313         }
314         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
315                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
316         free_page((unsigned long)tmpbuf);
317 #endif
318 }
319
320 static int bfs_fill_super(struct super_block *s, void *data, int silent)
321 {
322         struct buffer_head *bh, *sbh;
323         struct bfs_super_block *bfs_sb;
324         struct inode *inode;
325         unsigned i, imap_len;
326         struct bfs_sb_info *info;
327         int ret = -EINVAL;
328         unsigned long i_sblock, i_eblock, i_eoff, s_size;
329
330         info = kzalloc(sizeof(*info), GFP_KERNEL);
331         if (!info)
332                 return -ENOMEM;
333         mutex_init(&info->bfs_lock);
334         s->s_fs_info = info;
335
336         sb_set_blocksize(s, BFS_BSIZE);
337
338         sbh = sb_bread(s, 0);
339         if (!sbh)
340                 goto out;
341         bfs_sb = (struct bfs_super_block *)sbh->b_data;
342         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
343                 if (!silent)
344                         printf("No BFS filesystem on %s (magic=%08x)\n", 
345                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
346                 goto out1;
347         }
348         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
349                 printf("%s is unclean, continuing\n", s->s_id);
350
351         s->s_magic = BFS_MAGIC;
352
353         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
354             le32_to_cpu(bfs_sb->s_start) < BFS_BSIZE) {
355                 printf("Superblock is corrupted\n");
356                 goto out1;
357         }
358
359         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
360                                         sizeof(struct bfs_inode)
361                                         + BFS_ROOT_INO - 1;
362         imap_len = (info->si_lasti / 8) + 1;
363         info->si_imap = kzalloc(imap_len, GFP_KERNEL | __GFP_NOWARN);
364         if (!info->si_imap) {
365                 printf("Cannot allocate %u bytes\n", imap_len);
366                 goto out1;
367         }
368         for (i = 0; i < BFS_ROOT_INO; i++)
369                 set_bit(i, info->si_imap);
370
371         s->s_op = &bfs_sops;
372         inode = bfs_iget(s, BFS_ROOT_INO);
373         if (IS_ERR(inode)) {
374                 ret = PTR_ERR(inode);
375                 goto out2;
376         }
377         s->s_root = d_make_root(inode);
378         if (!s->s_root) {
379                 ret = -ENOMEM;
380                 goto out2;
381         }
382
383         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
384         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
385                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
386         info->si_freei = 0;
387         info->si_lf_eblk = 0;
388
389         /* can we read the last block? */
390         bh = sb_bread(s, info->si_blocks - 1);
391         if (!bh) {
392                 printf("Last block not available: %lu\n", info->si_blocks - 1);
393                 ret = -EIO;
394                 goto out3;
395         }
396         brelse(bh);
397
398         bh = NULL;
399         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
400                 struct bfs_inode *di;
401                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
402                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
403                 unsigned long eblock;
404
405                 if (!off) {
406                         brelse(bh);
407                         bh = sb_bread(s, block);
408                 }
409
410                 if (!bh)
411                         continue;
412
413                 di = (struct bfs_inode *)bh->b_data + off;
414
415                 /* test if filesystem is not corrupted */
416
417                 i_eoff = le32_to_cpu(di->i_eoffset);
418                 i_sblock = le32_to_cpu(di->i_sblock);
419                 i_eblock = le32_to_cpu(di->i_eblock);
420                 s_size = le32_to_cpu(bfs_sb->s_end);
421
422                 if (i_sblock > info->si_blocks ||
423                         i_eblock > info->si_blocks ||
424                         i_sblock > i_eblock ||
425                         i_eoff > s_size ||
426                         i_sblock * BFS_BSIZE > i_eoff) {
427
428                         printf("Inode 0x%08x corrupted\n", i);
429
430                         brelse(bh);
431                         ret = -EIO;
432                         goto out3;
433                 }
434
435                 if (!di->i_ino) {
436                         info->si_freei++;
437                         continue;
438                 }
439                 set_bit(i, info->si_imap);
440                 info->si_freeb -= BFS_FILEBLOCKS(di);
441
442                 eblock =  le32_to_cpu(di->i_eblock);
443                 if (eblock > info->si_lf_eblk)
444                         info->si_lf_eblk = eblock;
445         }
446         brelse(bh);
447         brelse(sbh);
448         bfs_dump_imap("read_super", s);
449         return 0;
450
451 out3:
452         dput(s->s_root);
453         s->s_root = NULL;
454 out2:
455         kfree(info->si_imap);
456 out1:
457         brelse(sbh);
458 out:
459         mutex_destroy(&info->bfs_lock);
460         kfree(info);
461         s->s_fs_info = NULL;
462         return ret;
463 }
464
465 static struct dentry *bfs_mount(struct file_system_type *fs_type,
466         int flags, const char *dev_name, void *data)
467 {
468         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
469 }
470
471 static struct file_system_type bfs_fs_type = {
472         .owner          = THIS_MODULE,
473         .name           = "bfs",
474         .mount          = bfs_mount,
475         .kill_sb        = kill_block_super,
476         .fs_flags       = FS_REQUIRES_DEV,
477 };
478 MODULE_ALIAS_FS("bfs");
479
480 static int __init init_bfs_fs(void)
481 {
482         int err = init_inodecache();
483         if (err)
484                 goto out1;
485         err = register_filesystem(&bfs_fs_type);
486         if (err)
487                 goto out;
488         return 0;
489 out:
490         destroy_inodecache();
491 out1:
492         return err;
493 }
494
495 static void __exit exit_bfs_fs(void)
496 {
497         unregister_filesystem(&bfs_fs_type);
498         destroy_inodecache();
499 }
500
501 module_init(init_bfs_fs)
502 module_exit(exit_bfs_fs)