Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux
[linux-3.10.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 <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
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         set_nlink(inode, 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
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
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
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         clear_inode(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
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
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
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
251 static void bfs_i_callback(struct rcu_head *head)
252 {
253         struct inode *inode = container_of(head, struct inode, i_rcu);
254         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
255 }
256
257 static void bfs_destroy_inode(struct inode *inode)
258 {
259         call_rcu(&inode->i_rcu, bfs_i_callback);
260 }
261
262 static void init_once(void *foo)
263 {
264         struct bfs_inode_info *bi = foo;
265
266         inode_init_once(&bi->vfs_inode);
267 }
268
269 static int init_inodecache(void)
270 {
271         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
272                                              sizeof(struct bfs_inode_info),
273                                              0, (SLAB_RECLAIM_ACCOUNT|
274                                                 SLAB_MEM_SPREAD),
275                                              init_once);
276         if (bfs_inode_cachep == NULL)
277                 return -ENOMEM;
278         return 0;
279 }
280
281 static void destroy_inodecache(void)
282 {
283         kmem_cache_destroy(bfs_inode_cachep);
284 }
285
286 static const struct super_operations bfs_sops = {
287         .alloc_inode    = bfs_alloc_inode,
288         .destroy_inode  = bfs_destroy_inode,
289         .write_inode    = bfs_write_inode,
290         .evict_inode    = bfs_evict_inode,
291         .put_super      = bfs_put_super,
292         .statfs         = bfs_statfs,
293 };
294
295 void dump_imap(const char *prefix, struct super_block *s)
296 {
297 #ifdef DEBUG
298         int i;
299         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
300
301         if (!tmpbuf)
302                 return;
303         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
304                 if (i > PAGE_SIZE - 100) break;
305                 if (test_bit(i, BFS_SB(s)->si_imap))
306                         strcat(tmpbuf, "1");
307                 else
308                         strcat(tmpbuf, "0");
309         }
310         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
311                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
312         free_page((unsigned long)tmpbuf);
313 #endif
314 }
315
316 static int bfs_fill_super(struct super_block *s, void *data, int silent)
317 {
318         struct buffer_head *bh, *sbh;
319         struct bfs_super_block *bfs_sb;
320         struct inode *inode;
321         unsigned i, imap_len;
322         struct bfs_sb_info *info;
323         int ret = -EINVAL;
324         unsigned long i_sblock, i_eblock, i_eoff, s_size;
325
326         info = kzalloc(sizeof(*info), GFP_KERNEL);
327         if (!info)
328                 return -ENOMEM;
329         mutex_init(&info->bfs_lock);
330         s->s_fs_info = info;
331
332         sb_set_blocksize(s, BFS_BSIZE);
333
334         sbh = sb_bread(s, 0);
335         if (!sbh)
336                 goto out;
337         bfs_sb = (struct bfs_super_block *)sbh->b_data;
338         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
339                 if (!silent)
340                         printf("No BFS filesystem on %s (magic=%08x)\n", 
341                                 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                 printf("Superblock is corrupted\n");
351                 goto out1;
352         }
353
354         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
355                                         sizeof(struct bfs_inode)
356                                         + BFS_ROOT_INO - 1;
357         imap_len = (info->si_lasti / 8) + 1;
358         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
359         if (!info->si_imap)
360                 goto out1;
361         for (i = 0; i < BFS_ROOT_INO; i++)
362                 set_bit(i, info->si_imap);
363
364         s->s_op = &bfs_sops;
365         inode = bfs_iget(s, BFS_ROOT_INO);
366         if (IS_ERR(inode)) {
367                 ret = PTR_ERR(inode);
368                 goto out2;
369         }
370         s->s_root = d_make_root(inode);
371         if (!s->s_root) {
372                 ret = -ENOMEM;
373                 goto out2;
374         }
375
376         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
377         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
378                         - 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: %lu\n", info->si_blocks - 1);
386                 ret = -EIO;
387                 goto out3;
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 > s_size ||
419                         i_sblock * BFS_BSIZE > i_eoff) {
420
421                         printf("Inode 0x%08x corrupted\n", i);
422
423                         brelse(bh);
424                         ret = -EIO;
425                         goto out3;
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         dump_imap("read_super", s);
442         return 0;
443
444 out3:
445         dput(s->s_root);
446         s->s_root = NULL;
447 out2:
448         kfree(info->si_imap);
449 out1:
450         brelse(sbh);
451 out:
452         mutex_destroy(&info->bfs_lock);
453         kfree(info);
454         s->s_fs_info = NULL;
455         return ret;
456 }
457
458 static struct dentry *bfs_mount(struct file_system_type *fs_type,
459         int flags, const char *dev_name, void *data)
460 {
461         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
462 }
463
464 static struct file_system_type bfs_fs_type = {
465         .owner          = THIS_MODULE,
466         .name           = "bfs",
467         .mount          = bfs_mount,
468         .kill_sb        = kill_block_super,
469         .fs_flags       = FS_REQUIRES_DEV,
470 };
471
472 static int __init init_bfs_fs(void)
473 {
474         int err = init_inodecache();
475         if (err)
476                 goto out1;
477         err = register_filesystem(&bfs_fs_type);
478         if (err)
479                 goto out;
480         return 0;
481 out:
482         destroy_inodecache();
483 out1:
484         return err;
485 }
486
487 static void __exit exit_bfs_fs(void)
488 {
489         unregister_filesystem(&bfs_fs_type);
490         destroy_inodecache();
491 }
492
493 module_init(init_bfs_fs)
494 module_exit(exit_bfs_fs)