GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / omfs / inode.c
1 /*
2  * Optimized MPEG FS - inode and super operations.
3  * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
4  * Released under GPL v2.
5  */
6 #include <linux/module.h>
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/fs.h>
10 #include <linux/vfs.h>
11 #include <linux/cred.h>
12 #include <linux/parser.h>
13 #include <linux/buffer_head.h>
14 #include <linux/vmalloc.h>
15 #include <linux/writeback.h>
16 #include <linux/seq_file.h>
17 #include <linux/crc-itu-t.h>
18 #include "omfs.h"
19
20 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
21 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
22 MODULE_LICENSE("GPL");
23
24 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
25 {
26         struct omfs_sb_info *sbi = OMFS_SB(sb);
27         if (block >= sbi->s_num_blocks)
28                 return NULL;
29
30         return sb_bread(sb, clus_to_blk(sbi, block));
31 }
32
33 struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
34 {
35         struct inode *inode;
36         u64 new_block;
37         int err;
38         int len;
39         struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
40
41         inode = new_inode(dir->i_sb);
42         if (!inode)
43                 return ERR_PTR(-ENOMEM);
44
45         err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
46                         &new_block, &len);
47         if (err)
48                 goto fail;
49
50         inode->i_ino = new_block;
51         inode_init_owner(inode, NULL, mode);
52         inode->i_mapping->a_ops = &omfs_aops;
53
54         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
55         switch (mode & S_IFMT) {
56         case S_IFDIR:
57                 inode->i_op = &omfs_dir_inops;
58                 inode->i_fop = &omfs_dir_operations;
59                 inode->i_size = sbi->s_sys_blocksize;
60                 inc_nlink(inode);
61                 break;
62         case S_IFREG:
63                 inode->i_op = &omfs_file_inops;
64                 inode->i_fop = &omfs_file_operations;
65                 inode->i_size = 0;
66                 break;
67         }
68
69         insert_inode_hash(inode);
70         mark_inode_dirty(inode);
71         return inode;
72 fail:
73         make_bad_inode(inode);
74         iput(inode);
75         return ERR_PTR(err);
76 }
77
78 /*
79  * Update the header checksums for a dirty inode based on its contents.
80  * Caller is expected to hold the buffer head underlying oi and mark it
81  * dirty.
82  */
83 static void omfs_update_checksums(struct omfs_inode *oi)
84 {
85         int xor, i, ofs = 0, count;
86         u16 crc = 0;
87         unsigned char *ptr = (unsigned char *) oi;
88
89         count = be32_to_cpu(oi->i_head.h_body_size);
90         ofs = sizeof(struct omfs_header);
91
92         crc = crc_itu_t(crc, ptr + ofs, count);
93         oi->i_head.h_crc = cpu_to_be16(crc);
94
95         xor = ptr[0];
96         for (i = 1; i < OMFS_XOR_COUNT; i++)
97                 xor ^= ptr[i];
98
99         oi->i_head.h_check_xor = xor;
100 }
101
102 static int __omfs_write_inode(struct inode *inode, int wait)
103 {
104         struct omfs_inode *oi;
105         struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
106         struct buffer_head *bh, *bh2;
107         u64 ctime;
108         int i;
109         int ret = -EIO;
110         int sync_failed = 0;
111
112         /* get current inode since we may have written sibling ptrs etc. */
113         bh = omfs_bread(inode->i_sb, inode->i_ino);
114         if (!bh)
115                 goto out;
116
117         oi = (struct omfs_inode *) bh->b_data;
118
119         oi->i_head.h_self = cpu_to_be64(inode->i_ino);
120         if (S_ISDIR(inode->i_mode))
121                 oi->i_type = OMFS_DIR;
122         else if (S_ISREG(inode->i_mode))
123                 oi->i_type = OMFS_FILE;
124         else {
125                 printk(KERN_WARNING "omfs: unknown file type: %d\n",
126                         inode->i_mode);
127                 goto out_brelse;
128         }
129
130         oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
131                 sizeof(struct omfs_header));
132         oi->i_head.h_version = 1;
133         oi->i_head.h_type = OMFS_INODE_NORMAL;
134         oi->i_head.h_magic = OMFS_IMAGIC;
135         oi->i_size = cpu_to_be64(inode->i_size);
136
137         ctime = inode->i_ctime.tv_sec * 1000LL +
138                 ((inode->i_ctime.tv_nsec + 999)/1000);
139         oi->i_ctime = cpu_to_be64(ctime);
140
141         omfs_update_checksums(oi);
142
143         mark_buffer_dirty(bh);
144         if (wait) {
145                 sync_dirty_buffer(bh);
146                 if (buffer_req(bh) && !buffer_uptodate(bh))
147                         sync_failed = 1;
148         }
149
150         /* if mirroring writes, copy to next fsblock */
151         for (i = 1; i < sbi->s_mirrors; i++) {
152                 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
153                 if (!bh2)
154                         goto out_brelse;
155
156                 memcpy(bh2->b_data, bh->b_data, bh->b_size);
157                 mark_buffer_dirty(bh2);
158                 if (wait) {
159                         sync_dirty_buffer(bh2);
160                         if (buffer_req(bh2) && !buffer_uptodate(bh2))
161                                 sync_failed = 1;
162                 }
163                 brelse(bh2);
164         }
165         ret = (sync_failed) ? -EIO : 0;
166 out_brelse:
167         brelse(bh);
168 out:
169         return ret;
170 }
171
172 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
173 {
174         return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
175 }
176
177 int omfs_sync_inode(struct inode *inode)
178 {
179         return __omfs_write_inode(inode, 1);
180 }
181
182 /*
183  * called when an entry is deleted, need to clear the bits in the
184  * bitmaps.
185  */
186 static void omfs_evict_inode(struct inode *inode)
187 {
188         truncate_inode_pages_final(&inode->i_data);
189         clear_inode(inode);
190
191         if (inode->i_nlink)
192                 return;
193
194         if (S_ISREG(inode->i_mode)) {
195                 inode->i_size = 0;
196                 omfs_shrink_inode(inode);
197         }
198
199         omfs_clear_range(inode->i_sb, inode->i_ino, 2);
200 }
201
202 struct inode *omfs_iget(struct super_block *sb, ino_t ino)
203 {
204         struct omfs_sb_info *sbi = OMFS_SB(sb);
205         struct omfs_inode *oi;
206         struct buffer_head *bh;
207         u64 ctime;
208         unsigned long nsecs;
209         struct inode *inode;
210
211         inode = iget_locked(sb, ino);
212         if (!inode)
213                 return ERR_PTR(-ENOMEM);
214         if (!(inode->i_state & I_NEW))
215                 return inode;
216
217         bh = omfs_bread(inode->i_sb, ino);
218         if (!bh)
219                 goto iget_failed;
220
221         oi = (struct omfs_inode *)bh->b_data;
222
223         /* check self */
224         if (ino != be64_to_cpu(oi->i_head.h_self))
225                 goto fail_bh;
226
227         inode->i_uid = sbi->s_uid;
228         inode->i_gid = sbi->s_gid;
229
230         ctime = be64_to_cpu(oi->i_ctime);
231         nsecs = do_div(ctime, 1000) * 1000L;
232
233         inode->i_atime.tv_sec = ctime;
234         inode->i_mtime.tv_sec = ctime;
235         inode->i_ctime.tv_sec = ctime;
236         inode->i_atime.tv_nsec = nsecs;
237         inode->i_mtime.tv_nsec = nsecs;
238         inode->i_ctime.tv_nsec = nsecs;
239
240         inode->i_mapping->a_ops = &omfs_aops;
241
242         switch (oi->i_type) {
243         case OMFS_DIR:
244                 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
245                 inode->i_op = &omfs_dir_inops;
246                 inode->i_fop = &omfs_dir_operations;
247                 inode->i_size = sbi->s_sys_blocksize;
248                 inc_nlink(inode);
249                 break;
250         case OMFS_FILE:
251                 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
252                 inode->i_fop = &omfs_file_operations;
253                 inode->i_size = be64_to_cpu(oi->i_size);
254                 break;
255         }
256         brelse(bh);
257         unlock_new_inode(inode);
258         return inode;
259 fail_bh:
260         brelse(bh);
261 iget_failed:
262         iget_failed(inode);
263         return ERR_PTR(-EIO);
264 }
265
266 static void omfs_put_super(struct super_block *sb)
267 {
268         struct omfs_sb_info *sbi = OMFS_SB(sb);
269         kfree(sbi->s_imap);
270         kfree(sbi);
271         sb->s_fs_info = NULL;
272 }
273
274 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
275 {
276         struct super_block *s = dentry->d_sb;
277         struct omfs_sb_info *sbi = OMFS_SB(s);
278         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
279
280         buf->f_type = OMFS_MAGIC;
281         buf->f_bsize = sbi->s_blocksize;
282         buf->f_blocks = sbi->s_num_blocks;
283         buf->f_files = sbi->s_num_blocks;
284         buf->f_namelen = OMFS_NAMELEN;
285         buf->f_fsid.val[0] = (u32)id;
286         buf->f_fsid.val[1] = (u32)(id >> 32);
287
288         buf->f_bfree = buf->f_bavail = buf->f_ffree =
289                 omfs_count_free(s);
290
291         return 0;
292 }
293
294 /*
295  * Display the mount options in /proc/mounts.
296  */
297 static int omfs_show_options(struct seq_file *m, struct dentry *root)
298 {
299         struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
300         umode_t cur_umask = current_umask();
301
302         if (!uid_eq(sbi->s_uid, current_uid()))
303                 seq_printf(m, ",uid=%u",
304                            from_kuid_munged(&init_user_ns, sbi->s_uid));
305         if (!gid_eq(sbi->s_gid, current_gid()))
306                 seq_printf(m, ",gid=%u",
307                            from_kgid_munged(&init_user_ns, sbi->s_gid));
308
309         if (sbi->s_dmask == sbi->s_fmask) {
310                 if (sbi->s_fmask != cur_umask)
311                         seq_printf(m, ",umask=%o", sbi->s_fmask);
312         } else {
313                 if (sbi->s_dmask != cur_umask)
314                         seq_printf(m, ",dmask=%o", sbi->s_dmask);
315                 if (sbi->s_fmask != cur_umask)
316                         seq_printf(m, ",fmask=%o", sbi->s_fmask);
317         }
318
319         return 0;
320 }
321
322 static const struct super_operations omfs_sops = {
323         .write_inode    = omfs_write_inode,
324         .evict_inode    = omfs_evict_inode,
325         .put_super      = omfs_put_super,
326         .statfs         = omfs_statfs,
327         .show_options   = omfs_show_options,
328 };
329
330 /*
331  * For Rio Karma, there is an on-disk free bitmap whose location is
332  * stored in the root block.  For ReplayTV, there is no such free bitmap
333  * so we have to walk the tree.  Both inodes and file data are allocated
334  * from the same map.  This array can be big (300k) so we allocate
335  * in units of the blocksize.
336  */
337 static int omfs_get_imap(struct super_block *sb)
338 {
339         unsigned int bitmap_size, array_size;
340         int count;
341         struct omfs_sb_info *sbi = OMFS_SB(sb);
342         struct buffer_head *bh;
343         unsigned long **ptr;
344         sector_t block;
345
346         bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
347         array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
348
349         if (sbi->s_bitmap_ino == ~0ULL)
350                 goto out;
351
352         sbi->s_imap_size = array_size;
353         sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
354         if (!sbi->s_imap)
355                 goto nomem;
356
357         block = clus_to_blk(sbi, sbi->s_bitmap_ino);
358         if (block >= sbi->s_num_blocks)
359                 goto nomem;
360
361         ptr = sbi->s_imap;
362         for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
363                 bh = sb_bread(sb, block++);
364                 if (!bh)
365                         goto nomem_free;
366                 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
367                 if (!*ptr) {
368                         brelse(bh);
369                         goto nomem_free;
370                 }
371                 memcpy(*ptr, bh->b_data, sb->s_blocksize);
372                 if (count < sb->s_blocksize)
373                         memset((void *)*ptr + count, 0xff,
374                                 sb->s_blocksize - count);
375                 brelse(bh);
376                 ptr++;
377         }
378 out:
379         return 0;
380
381 nomem_free:
382         for (count = 0; count < array_size; count++)
383                 kfree(sbi->s_imap[count]);
384
385         kfree(sbi->s_imap);
386 nomem:
387         sbi->s_imap = NULL;
388         sbi->s_imap_size = 0;
389         return -ENOMEM;
390 }
391
392 enum {
393         Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err
394 };
395
396 static const match_table_t tokens = {
397         {Opt_uid, "uid=%u"},
398         {Opt_gid, "gid=%u"},
399         {Opt_umask, "umask=%o"},
400         {Opt_dmask, "dmask=%o"},
401         {Opt_fmask, "fmask=%o"},
402         {Opt_err, NULL},
403 };
404
405 static int parse_options(char *options, struct omfs_sb_info *sbi)
406 {
407         char *p;
408         substring_t args[MAX_OPT_ARGS];
409         int option;
410
411         if (!options)
412                 return 1;
413
414         while ((p = strsep(&options, ",")) != NULL) {
415                 int token;
416                 if (!*p)
417                         continue;
418
419                 token = match_token(p, tokens, args);
420                 switch (token) {
421                 case Opt_uid:
422                         if (match_int(&args[0], &option))
423                                 return 0;
424                         sbi->s_uid = make_kuid(current_user_ns(), option);
425                         if (!uid_valid(sbi->s_uid))
426                                 return 0;
427                         break;
428                 case Opt_gid:
429                         if (match_int(&args[0], &option))
430                                 return 0;
431                         sbi->s_gid = make_kgid(current_user_ns(), option);
432                         if (!gid_valid(sbi->s_gid))
433                                 return 0;
434                         break;
435                 case Opt_umask:
436                         if (match_octal(&args[0], &option))
437                                 return 0;
438                         sbi->s_fmask = sbi->s_dmask = option;
439                         break;
440                 case Opt_dmask:
441                         if (match_octal(&args[0], &option))
442                                 return 0;
443                         sbi->s_dmask = option;
444                         break;
445                 case Opt_fmask:
446                         if (match_octal(&args[0], &option))
447                                 return 0;
448                         sbi->s_fmask = option;
449                         break;
450                 default:
451                         return 0;
452                 }
453         }
454         return 1;
455 }
456
457 static int omfs_fill_super(struct super_block *sb, void *data, int silent)
458 {
459         struct buffer_head *bh, *bh2;
460         struct omfs_super_block *omfs_sb;
461         struct omfs_root_block *omfs_rb;
462         struct omfs_sb_info *sbi;
463         struct inode *root;
464         int ret = -EINVAL;
465
466         sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
467         if (!sbi)
468                 return -ENOMEM;
469
470         sb->s_fs_info = sbi;
471
472         sbi->s_uid = current_uid();
473         sbi->s_gid = current_gid();
474         sbi->s_dmask = sbi->s_fmask = current_umask();
475
476         if (!parse_options((char *) data, sbi))
477                 goto end;
478
479         sb->s_maxbytes = 0xffffffff;
480
481         sb_set_blocksize(sb, 0x200);
482
483         bh = sb_bread(sb, 0);
484         if (!bh)
485                 goto end;
486
487         omfs_sb = (struct omfs_super_block *)bh->b_data;
488
489         if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
490                 if (!silent)
491                         printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
492                                    omfs_sb->s_magic);
493                 goto out_brelse_bh;
494         }
495         sb->s_magic = OMFS_MAGIC;
496
497         sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
498         sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
499         sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
500         sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
501         sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
502         mutex_init(&sbi->s_bitmap_lock);
503
504         if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
505                 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
506                        (unsigned long long)sbi->s_num_blocks);
507                 goto out_brelse_bh;
508         }
509
510         if (sbi->s_sys_blocksize > PAGE_SIZE) {
511                 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
512                         sbi->s_sys_blocksize);
513                 goto out_brelse_bh;
514         }
515
516         if (sbi->s_blocksize < sbi->s_sys_blocksize ||
517             sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
518                 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
519                         sbi->s_blocksize);
520                 goto out_brelse_bh;
521         }
522
523         /*
524          * Use sys_blocksize as the fs block since it is smaller than a
525          * page while the fs blocksize can be larger.
526          */
527         sb_set_blocksize(sb, sbi->s_sys_blocksize);
528
529         /*
530          * ...and the difference goes into a shift.  sys_blocksize is always
531          * a power of two factor of blocksize.
532          */
533         sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
534                 get_bitmask_order(sbi->s_sys_blocksize);
535
536         bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
537         if (!bh2)
538                 goto out_brelse_bh;
539
540         omfs_rb = (struct omfs_root_block *)bh2->b_data;
541
542         sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
543         sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
544
545         if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
546                 printk(KERN_ERR "omfs: block count discrepancy between "
547                         "super and root blocks (%llx, %llx)\n",
548                         (unsigned long long)sbi->s_num_blocks,
549                         (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
550                 goto out_brelse_bh2;
551         }
552
553         if (sbi->s_bitmap_ino != ~0ULL &&
554             sbi->s_bitmap_ino > sbi->s_num_blocks) {
555                 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
556                         "(%llx, total blocks %llx)\n",
557                         (unsigned long long) sbi->s_bitmap_ino,
558                         (unsigned long long) sbi->s_num_blocks);
559                 goto out_brelse_bh2;
560         }
561         if (sbi->s_clustersize < 1 ||
562             sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
563                 printk(KERN_ERR "omfs: cluster size out of range (%d)",
564                         sbi->s_clustersize);
565                 goto out_brelse_bh2;
566         }
567
568         ret = omfs_get_imap(sb);
569         if (ret)
570                 goto out_brelse_bh2;
571
572         sb->s_op = &omfs_sops;
573
574         root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
575         if (IS_ERR(root)) {
576                 ret = PTR_ERR(root);
577                 goto out_brelse_bh2;
578         }
579
580         sb->s_root = d_make_root(root);
581         if (!sb->s_root) {
582                 ret = -ENOMEM;
583                 goto out_brelse_bh2;
584         }
585         printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
586
587         ret = 0;
588 out_brelse_bh2:
589         brelse(bh2);
590 out_brelse_bh:
591         brelse(bh);
592 end:
593         if (ret)
594                 kfree(sbi);
595         return ret;
596 }
597
598 static struct dentry *omfs_mount(struct file_system_type *fs_type,
599                         int flags, const char *dev_name, void *data)
600 {
601         return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
602 }
603
604 static struct file_system_type omfs_fs_type = {
605         .owner = THIS_MODULE,
606         .name = "omfs",
607         .mount = omfs_mount,
608         .kill_sb = kill_block_super,
609         .fs_flags = FS_REQUIRES_DEV,
610 };
611 MODULE_ALIAS_FS("omfs");
612
613 static int __init init_omfs_fs(void)
614 {
615         return register_filesystem(&omfs_fs_type);
616 }
617
618 static void __exit exit_omfs_fs(void)
619 {
620         unregister_filesystem(&omfs_fs_type);
621 }
622
623 module_init(init_omfs_fs);
624 module_exit(exit_omfs_fs);