xref: /linux/fs/minix/inode.c (revision f4cdf7ca9a1fdcca413157df19753f388a5a224e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/minix/inode.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  *
7  *  Copyright (C) 1996  Gertjan van Wingerde
8  *	Minix V2 fs support.
9  *
10  *  Modified for 680x0 by Andreas Schwab
11  *  Updated to filesystem version 3 by Daniel Aragones
12  */
13 
14 #include <linux/module.h>
15 #include "minix.h"
16 #include <linux/buffer_head.h>
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/highuid.h>
20 #include <linux/mpage.h>
21 #include <linux/vfs.h>
22 #include <linux/writeback.h>
23 #include <linux/fs_context.h>
24 
25 static int minix_write_inode(struct inode *inode,
26 		struct writeback_control *wbc);
27 static int minix_sync_inode_metadata(struct inode *inode,
28 				     struct writeback_control *wbc);
29 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
30 
31 void __minix_error_inode(struct inode *inode, const char *function,
32 			 unsigned int line, const char *fmt, ...)
33 {
34 	struct va_format vaf;
35 	va_list args;
36 
37 	va_start(args, fmt);
38 	vaf.fmt = fmt;
39 	vaf.va = &args;
40 	printk(KERN_CRIT "minix-fs error (device %s): %s:%d: "
41 	       "inode #%llu: comm %s: %pV\n",
42 	       inode->i_sb->s_id, function, line, inode->i_ino,
43 	       current->comm, &vaf);
44 	va_end(args);
45 }
46 
47 static void minix_evict_inode(struct inode *inode)
48 {
49 	truncate_inode_pages_final(&inode->i_data);
50 	if (!inode->i_nlink) {
51 		inode->i_size = 0;
52 		minix_truncate(inode);
53 	} else {
54 		mmb_sync(&minix_i(inode)->i_metadata_bhs);
55 	}
56 	mmb_invalidate(&minix_i(inode)->i_metadata_bhs);
57 	clear_inode(inode);
58 	if (!inode->i_nlink)
59 		minix_free_inode(inode);
60 }
61 
62 static void minix_put_super(struct super_block *sb)
63 {
64 	int i;
65 	struct minix_sb_info *sbi = minix_sb(sb);
66 
67 	if (!sb_rdonly(sb)) {
68 		if (sbi->s_version != MINIX_V3)	 /* s_state is now out from V3 sb */
69 			sbi->s_ms->s_state = sbi->s_mount_state;
70 		mark_buffer_dirty(sbi->s_sbh);
71 	}
72 	for (i = 0; i < sbi->s_imap_blocks; i++)
73 		brelse(sbi->s_imap[i]);
74 	for (i = 0; i < sbi->s_zmap_blocks; i++)
75 		brelse(sbi->s_zmap[i]);
76 	brelse (sbi->s_sbh);
77 	kfree(sbi->s_imap);
78 	sb->s_fs_info = NULL;
79 	kfree(sbi);
80 }
81 
82 static struct kmem_cache * minix_inode_cachep;
83 
84 static struct inode *minix_alloc_inode(struct super_block *sb)
85 {
86 	struct minix_inode_info *ei;
87 	ei = alloc_inode_sb(sb, minix_inode_cachep, GFP_KERNEL);
88 	if (!ei)
89 		return NULL;
90 	mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data);
91 
92 	return &ei->vfs_inode;
93 }
94 
95 static void minix_free_in_core_inode(struct inode *inode)
96 {
97 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
98 }
99 
100 static void init_once(void *foo)
101 {
102 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
103 
104 	inode_init_once(&ei->vfs_inode);
105 }
106 
107 static int __init init_inodecache(void)
108 {
109 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
110 					     sizeof(struct minix_inode_info),
111 					     0, (SLAB_RECLAIM_ACCOUNT|
112 						SLAB_ACCOUNT),
113 					     init_once);
114 	if (minix_inode_cachep == NULL)
115 		return -ENOMEM;
116 	return 0;
117 }
118 
119 static void destroy_inodecache(void)
120 {
121 	/*
122 	 * Make sure all delayed rcu free inodes are flushed before we
123 	 * destroy cache.
124 	 */
125 	rcu_barrier();
126 	kmem_cache_destroy(minix_inode_cachep);
127 }
128 
129 static const struct super_operations minix_sops = {
130 	.alloc_inode	= minix_alloc_inode,
131 	.free_inode	= minix_free_in_core_inode,
132 	.write_inode	= minix_write_inode,
133 	.sync_inode_metadata = minix_sync_inode_metadata,
134 	.evict_inode	= minix_evict_inode,
135 	.put_super	= minix_put_super,
136 	.statfs		= minix_statfs,
137 };
138 
139 static int minix_reconfigure(struct fs_context *fc)
140 {
141 	struct minix_super_block * ms;
142 	struct super_block *sb = fc->root->d_sb;
143 	struct minix_sb_info * sbi = sb->s_fs_info;
144 
145 	sync_filesystem(sb);
146 	ms = sbi->s_ms;
147 	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
148 		return 0;
149 	if (fc->sb_flags & SB_RDONLY) {
150 		if (ms->s_state & MINIX_VALID_FS ||
151 		    !(sbi->s_mount_state & MINIX_VALID_FS))
152 			return 0;
153 		/* Mounting a rw partition read-only. */
154 		if (sbi->s_version != MINIX_V3)
155 			ms->s_state = sbi->s_mount_state;
156 		mark_buffer_dirty(sbi->s_sbh);
157 	} else {
158 	  	/* Mount a partition which is read-only, read-write. */
159 		if (sbi->s_version != MINIX_V3) {
160 			sbi->s_mount_state = ms->s_state;
161 			ms->s_state &= ~MINIX_VALID_FS;
162 		} else {
163 			sbi->s_mount_state = MINIX_VALID_FS;
164 		}
165 		mark_buffer_dirty(sbi->s_sbh);
166 
167 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
168 			printk("MINIX-fs warning: remounting unchecked fs, "
169 				"running fsck is recommended\n");
170 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
171 			printk("MINIX-fs warning: remounting fs with errors, "
172 				"running fsck is recommended\n");
173 	}
174 	return 0;
175 }
176 
177 static bool minix_check_superblock(struct super_block *sb)
178 {
179 	struct minix_sb_info *sbi = minix_sb(sb);
180 	unsigned long block;
181 
182 	if (sbi->s_log_zone_size != 0) {
183 		printk("minix-fs error: zone size must equal block size. "
184 		       "s_log_zone_size > 0 is not supported.\n");
185 		return false;
186 	}
187 
188 	if (sbi->s_ninodes < 1 || sbi->s_firstdatazone <= 4 ||
189 	    sbi->s_firstdatazone >= sbi->s_nzones)
190 		return false;
191 
192 	/* Apparently minix can create filesystems that allocate more blocks for
193 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
194 	 * create one with not enough blocks and bail out if so.
195 	 */
196 	block = minix_blocks_needed(sbi->s_ninodes, sb->s_blocksize);
197 	if (sbi->s_imap_blocks < block) {
198 		printk("MINIX-fs: file system does not have enough "
199 		       "imap blocks allocated. Refusing to mount.\n");
200 		return false;
201 	}
202 
203 	block = minix_blocks_needed(
204 			(sbi->s_nzones - sbi->s_firstdatazone + 1),
205 			sb->s_blocksize);
206 	if (sbi->s_zmap_blocks < block) {
207 		printk("MINIX-fs: file system does not have enough "
208 		       "zmap blocks allocated. Refusing to mount.\n");
209 		return false;
210 	}
211 
212 	/*
213 	 * s_max_size must not exceed the block mapping limitation.  This check
214 	 * is only needed for V1 filesystems, since V2/V3 support an extra level
215 	 * of indirect blocks which places the limit well above U32_MAX.
216 	 */
217 	if (sbi->s_version == MINIX_V1 &&
218 	    sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE)
219 		return false;
220 
221 	return true;
222 }
223 
224 static int minix_fill_super(struct super_block *s, struct fs_context *fc)
225 {
226 	struct buffer_head *bh;
227 	struct buffer_head **map;
228 	struct minix_super_block *ms;
229 	struct minix3_super_block *m3s = NULL;
230 	unsigned long i, block;
231 	struct inode *root_inode;
232 	struct minix_sb_info *sbi;
233 	int ret = -EINVAL;
234 	int silent = fc->sb_flags & SB_SILENT;
235 
236 	sbi = kzalloc_obj(struct minix_sb_info);
237 	if (!sbi)
238 		return -ENOMEM;
239 	s->s_fs_info = sbi;
240 
241 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
242 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
243 
244 	if (!sb_set_blocksize(s, BLOCK_SIZE))
245 		goto out_bad_hblock;
246 
247 	if (!(bh = sb_bread(s, 1)))
248 		goto out_bad_sb;
249 
250 	ms = (struct minix_super_block *) bh->b_data;
251 	sbi->s_ms = ms;
252 	sbi->s_sbh = bh;
253 	sbi->s_mount_state = ms->s_state;
254 	sbi->s_ninodes = ms->s_ninodes;
255 	sbi->s_nzones = ms->s_nzones;
256 	sbi->s_imap_blocks = ms->s_imap_blocks;
257 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
258 	sbi->s_firstdatazone = ms->s_firstdatazone;
259 	sbi->s_log_zone_size = ms->s_log_zone_size;
260 	s->s_maxbytes = ms->s_max_size;
261 	s->s_magic = ms->s_magic;
262 	if (s->s_magic == MINIX_SUPER_MAGIC) {
263 		sbi->s_version = MINIX_V1;
264 		sbi->s_dirsize = 16;
265 		sbi->s_namelen = 14;
266 		s->s_max_links = MINIX_LINK_MAX;
267 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
268 		sbi->s_version = MINIX_V1;
269 		sbi->s_dirsize = 32;
270 		sbi->s_namelen = 30;
271 		s->s_max_links = MINIX_LINK_MAX;
272 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
273 		sbi->s_version = MINIX_V2;
274 		sbi->s_nzones = ms->s_zones;
275 		sbi->s_dirsize = 16;
276 		sbi->s_namelen = 14;
277 		s->s_max_links = MINIX2_LINK_MAX;
278 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
279 		sbi->s_version = MINIX_V2;
280 		sbi->s_nzones = ms->s_zones;
281 		sbi->s_dirsize = 32;
282 		sbi->s_namelen = 30;
283 		s->s_max_links = MINIX2_LINK_MAX;
284 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
285 		m3s = (struct minix3_super_block *) bh->b_data;
286 		s->s_magic = m3s->s_magic;
287 		sbi->s_imap_blocks = m3s->s_imap_blocks;
288 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
289 		sbi->s_firstdatazone = m3s->s_firstdatazone;
290 		sbi->s_log_zone_size = m3s->s_log_zone_size;
291 		s->s_maxbytes = m3s->s_max_size;
292 		sbi->s_ninodes = m3s->s_ninodes;
293 		sbi->s_nzones = m3s->s_zones;
294 		sbi->s_dirsize = 64;
295 		sbi->s_namelen = 60;
296 		sbi->s_version = MINIX_V3;
297 		sbi->s_mount_state = MINIX_VALID_FS;
298 		if (!sb_set_blocksize(s, m3s->s_blocksize))
299 			goto out_release;
300 		s->s_max_links = MINIX2_LINK_MAX;
301 	} else
302 		goto out_no_fs;
303 
304 	if (!minix_check_superblock(s))
305 		goto out_illegal_sb;
306 
307 	/*
308 	 * Allocate the buffer map to keep the superblock small.
309 	 */
310 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
311 	map = kzalloc(i, GFP_KERNEL);
312 	if (!map)
313 		goto out_no_map;
314 	sbi->s_imap = &map[0];
315 	sbi->s_zmap = &map[sbi->s_imap_blocks];
316 
317 	block=2;
318 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
319 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
320 			goto out_no_bitmap;
321 		block++;
322 	}
323 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
324 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
325 			goto out_no_bitmap;
326 		block++;
327 	}
328 
329 	minix_set_bit(0,sbi->s_imap[0]->b_data);
330 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
331 
332 	/* set up enough so that it can read an inode */
333 	s->s_op = &minix_sops;
334 	s->s_time_min = 0;
335 	s->s_time_max = U32_MAX;
336 	root_inode = minix_iget(s, MINIX_ROOT_INO);
337 	if (IS_ERR(root_inode)) {
338 		ret = PTR_ERR(root_inode);
339 		goto out_no_root;
340 	}
341 
342 	ret = -ENOMEM;
343 	s->s_root = d_make_root(root_inode);
344 	if (!s->s_root)
345 		goto out_no_root;
346 
347 	if (!sb_rdonly(s)) {
348 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
349 			ms->s_state &= ~MINIX_VALID_FS;
350 		mark_buffer_dirty(bh);
351 	}
352 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
353 		printk("MINIX-fs: mounting unchecked file system, "
354 			"running fsck is recommended\n");
355 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
356 		printk("MINIX-fs: mounting file system with errors, "
357 			"running fsck is recommended\n");
358 
359 	return 0;
360 
361 out_no_root:
362 	if (!silent)
363 		printk("MINIX-fs: get root inode failed\n");
364 	goto out_freemap;
365 
366 out_no_bitmap:
367 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
368 out_freemap:
369 	for (i = 0; i < sbi->s_imap_blocks; i++)
370 		brelse(sbi->s_imap[i]);
371 	for (i = 0; i < sbi->s_zmap_blocks; i++)
372 		brelse(sbi->s_zmap[i]);
373 	kfree(sbi->s_imap);
374 	goto out_release;
375 
376 out_no_map:
377 	ret = -ENOMEM;
378 	if (!silent)
379 		printk("MINIX-fs: can't allocate map\n");
380 	goto out_release;
381 
382 out_illegal_sb:
383 	if (!silent)
384 		printk("MINIX-fs: bad superblock\n");
385 	goto out_release;
386 
387 out_no_fs:
388 	if (!silent)
389 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
390 		       "on device %s.\n", s->s_id);
391 out_release:
392 	brelse(bh);
393 	goto out;
394 
395 out_bad_hblock:
396 	printk("MINIX-fs: blocksize too small for device\n");
397 	goto out;
398 
399 out_bad_sb:
400 	printk("MINIX-fs: unable to read superblock\n");
401 out:
402 	s->s_fs_info = NULL;
403 	kfree(sbi);
404 	return ret;
405 }
406 
407 static int minix_get_tree(struct fs_context *fc)
408 {
409 	 return get_tree_bdev(fc, minix_fill_super);
410 }
411 
412 static const struct fs_context_operations minix_context_ops = {
413 	.get_tree	= minix_get_tree,
414 	.reconfigure	= minix_reconfigure,
415 };
416 
417 static int minix_init_fs_context(struct fs_context *fc)
418 {
419 	fc->ops = &minix_context_ops;
420 
421 	return 0;
422 }
423 
424 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
425 {
426 	struct super_block *sb = dentry->d_sb;
427 	struct minix_sb_info *sbi = minix_sb(sb);
428 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
429 	buf->f_type = sb->s_magic;
430 	buf->f_bsize = sb->s_blocksize;
431 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
432 	buf->f_bfree = minix_count_free_blocks(sb);
433 	buf->f_bavail = buf->f_bfree;
434 	buf->f_files = sbi->s_ninodes;
435 	buf->f_ffree = minix_count_free_inodes(sb);
436 	buf->f_namelen = sbi->s_namelen;
437 	buf->f_fsid = u64_to_fsid(id);
438 
439 	return 0;
440 }
441 
442 static int minix_get_block(struct inode *inode, sector_t block,
443 		    struct buffer_head *bh_result, int create)
444 {
445 	if (INODE_VERSION(inode) == MINIX_V1)
446 		return V1_minix_get_block(inode, block, bh_result, create);
447 	else
448 		return V2_minix_get_block(inode, block, bh_result, create);
449 }
450 
451 static int minix_writepages(struct address_space *mapping,
452 		struct writeback_control *wbc)
453 {
454 	return mpage_writepages(mapping, wbc, minix_get_block);
455 }
456 
457 static int minix_read_folio(struct file *file, struct folio *folio)
458 {
459 	return block_read_full_folio(folio, minix_get_block);
460 }
461 
462 int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
463 {
464 	return __block_write_begin(folio, pos, len, minix_get_block);
465 }
466 
467 static void minix_write_failed(struct address_space *mapping, loff_t to)
468 {
469 	struct inode *inode = mapping->host;
470 
471 	if (to > inode->i_size) {
472 		truncate_pagecache(inode, inode->i_size);
473 		minix_truncate(inode);
474 	}
475 }
476 
477 static int minix_write_begin(const struct kiocb *iocb,
478 			     struct address_space *mapping,
479 			     loff_t pos, unsigned len,
480 			     struct folio **foliop, void **fsdata)
481 {
482 	int ret;
483 
484 	ret = block_write_begin(mapping, pos, len, foliop, minix_get_block);
485 	if (unlikely(ret))
486 		minix_write_failed(mapping, pos + len);
487 
488 	return ret;
489 }
490 
491 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
492 {
493 	return generic_block_bmap(mapping,block,minix_get_block);
494 }
495 
496 static const struct address_space_operations minix_aops = {
497 	.dirty_folio	= block_dirty_folio,
498 	.invalidate_folio = block_invalidate_folio,
499 	.read_folio = minix_read_folio,
500 	.writepages = minix_writepages,
501 	.write_begin = minix_write_begin,
502 	.write_end = generic_write_end,
503 	.migrate_folio = buffer_migrate_folio,
504 	.bmap = minix_bmap,
505 	.direct_IO = noop_direct_IO
506 };
507 
508 static const struct inode_operations minix_symlink_inode_operations = {
509 	.get_link	= page_get_link,
510 	.getattr	= minix_getattr,
511 };
512 
513 void minix_set_inode(struct inode *inode, dev_t rdev)
514 {
515 	if (S_ISREG(inode->i_mode)) {
516 		inode->i_op = &minix_file_inode_operations;
517 		inode->i_fop = &minix_file_operations;
518 		inode->i_mapping->a_ops = &minix_aops;
519 	} else if (S_ISDIR(inode->i_mode)) {
520 		inode->i_op = &minix_dir_inode_operations;
521 		inode->i_fop = &minix_dir_operations;
522 		inode->i_mapping->a_ops = &minix_aops;
523 	} else if (S_ISLNK(inode->i_mode)) {
524 		inode->i_op = &minix_symlink_inode_operations;
525 		inode_nohighmem(inode);
526 		inode->i_mapping->a_ops = &minix_aops;
527 	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
528 		   S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
529 		init_special_inode(inode, inode->i_mode, rdev);
530 	} else {
531 		printk(KERN_DEBUG "MINIX-fs: Invalid file type 0%04o for inode %llu.\n",
532 		       inode->i_mode, inode->i_ino);
533 		make_bad_inode(inode);
534 	}
535 }
536 
537 /*
538  * The minix V1 function to read an inode.
539  */
540 static struct inode *V1_minix_iget(struct inode *inode)
541 {
542 	struct buffer_head * bh;
543 	struct minix_inode * raw_inode;
544 	struct minix_inode_info *minix_inode = minix_i(inode);
545 	int i;
546 
547 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
548 	if (!raw_inode) {
549 		iget_failed(inode);
550 		return ERR_PTR(-EIO);
551 	}
552 	if (raw_inode->i_nlinks == 0) {
553 		printk("MINIX-fs: deleted inode referenced: %llu\n",
554 		       inode->i_ino);
555 		brelse(bh);
556 		iget_failed(inode);
557 		return ERR_PTR(-ESTALE);
558 	}
559 	inode->i_mode = raw_inode->i_mode;
560 	i_uid_write(inode, raw_inode->i_uid);
561 	i_gid_write(inode, raw_inode->i_gid);
562 	set_nlink(inode, raw_inode->i_nlinks);
563 	inode->i_size = raw_inode->i_size;
564 	inode_set_mtime_to_ts(inode,
565 			      inode_set_atime_to_ts(inode, inode_set_ctime(inode, raw_inode->i_time, 0)));
566 	inode->i_blocks = 0;
567 	for (i = 0; i < 9; i++)
568 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
569 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
570 	brelse(bh);
571 	unlock_new_inode(inode);
572 	return inode;
573 }
574 
575 /*
576  * The minix V2 function to read an inode.
577  */
578 static struct inode *V2_minix_iget(struct inode *inode)
579 {
580 	struct buffer_head * bh;
581 	struct minix2_inode * raw_inode;
582 	struct minix_inode_info *minix_inode = minix_i(inode);
583 	int i;
584 
585 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
586 	if (!raw_inode) {
587 		iget_failed(inode);
588 		return ERR_PTR(-EIO);
589 	}
590 	if (raw_inode->i_nlinks == 0) {
591 		printk("MINIX-fs: deleted inode referenced: %llu\n",
592 		       inode->i_ino);
593 		brelse(bh);
594 		iget_failed(inode);
595 		return ERR_PTR(-ESTALE);
596 	}
597 	inode->i_mode = raw_inode->i_mode;
598 	i_uid_write(inode, raw_inode->i_uid);
599 	i_gid_write(inode, raw_inode->i_gid);
600 	set_nlink(inode, raw_inode->i_nlinks);
601 	inode->i_size = raw_inode->i_size;
602 	inode_set_mtime(inode, raw_inode->i_mtime, 0);
603 	inode_set_atime(inode, raw_inode->i_atime, 0);
604 	inode_set_ctime(inode, raw_inode->i_ctime, 0);
605 	inode->i_blocks = 0;
606 	for (i = 0; i < 10; i++)
607 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
608 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
609 	brelse(bh);
610 	unlock_new_inode(inode);
611 	return inode;
612 }
613 
614 /*
615  * The global function to read an inode.
616  */
617 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
618 {
619 	struct inode *inode;
620 
621 	inode = iget_locked(sb, ino);
622 	if (!inode)
623 		return ERR_PTR(-ENOMEM);
624 	if (!(inode_state_read_once(inode) & I_NEW))
625 		return inode;
626 
627 	if (INODE_VERSION(inode) == MINIX_V1)
628 		return V1_minix_iget(inode);
629 	else
630 		return V2_minix_iget(inode);
631 }
632 
633 /*
634  * The minix V1 function to synchronize an inode.
635  */
636 static int V1_minix_update_inode(struct inode * inode)
637 {
638 	struct buffer_head * bh;
639 	struct minix_inode * raw_inode;
640 	struct minix_inode_info *minix_inode = minix_i(inode);
641 	int i;
642 
643 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
644 	if (!raw_inode)
645 		return -EIO;
646 	raw_inode->i_mode = inode->i_mode;
647 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
648 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
649 	raw_inode->i_nlinks = inode->i_nlink;
650 	raw_inode->i_size = inode->i_size;
651 	raw_inode->i_time = inode_get_mtime_sec(inode);
652 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
653 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
654 	else for (i = 0; i < 9; i++)
655 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
656 	mark_buffer_dirty(bh);
657 	brelse(bh);
658 	set_inode_metadata_writeback(inode);
659 	return 0;
660 }
661 
662 /*
663  * The minix V2 function to synchronize an inode.
664  */
665 static int V2_minix_update_inode(struct inode * inode)
666 {
667 	struct buffer_head * bh;
668 	struct minix2_inode * raw_inode;
669 	struct minix_inode_info *minix_inode = minix_i(inode);
670 	int i;
671 
672 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
673 	if (!raw_inode)
674 		return -EIO;
675 	raw_inode->i_mode = inode->i_mode;
676 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
677 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
678 	raw_inode->i_nlinks = inode->i_nlink;
679 	raw_inode->i_size = inode->i_size;
680 	raw_inode->i_mtime = inode_get_mtime_sec(inode);
681 	raw_inode->i_atime = inode_get_atime_sec(inode);
682 	raw_inode->i_ctime = inode_get_ctime_sec(inode);
683 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
684 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
685 	else for (i = 0; i < 10; i++)
686 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
687 	mark_buffer_dirty(bh);
688 	brelse(bh);
689 	set_inode_metadata_writeback(inode);
690 	return 0;
691 }
692 
693 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
694 {
695 	if (INODE_VERSION(inode) == MINIX_V1)
696 		return V1_minix_update_inode(inode);
697 	return V2_minix_update_inode(inode);
698 }
699 
700 static int minix_sync_inode_metadata(struct inode *inode,
701 				     struct writeback_control *wbc)
702 {
703 	int err = 0;
704 	struct buffer_head *bh;
705 	void *raw_inode;
706 
707 	if (INODE_VERSION(inode) == MINIX_V1)
708 		raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
709 	else
710 		raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
711 	if (!raw_inode)
712 		return -EIO;
713 	err = mmb_sync(&minix_i(inode)->i_metadata_bhs);
714 	if (err)
715 		goto out;
716 	sync_dirty_buffer(bh);
717 	if (buffer_write_io_error(bh)) {
718 		printk("IO error syncing minix inode [%s:%08llx]\n",
719 			inode->i_sb->s_id, inode->i_ino);
720 		err = -EIO;
721 	}
722 out:
723 	brelse(bh);
724 	return err;
725 }
726 
727 int minix_getattr(struct mnt_idmap *idmap, const struct path *path,
728 		  struct kstat *stat, u32 request_mask, unsigned int flags)
729 {
730 	struct super_block *sb = path->dentry->d_sb;
731 	struct inode *inode = d_inode(path->dentry);
732 
733 	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
734 	if (INODE_VERSION(inode) == MINIX_V1)
735 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
736 	else
737 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
738 	stat->blksize = sb->s_blocksize;
739 	return 0;
740 }
741 
742 /*
743  * The function that is called for file truncation.
744  */
745 void minix_truncate(struct inode * inode)
746 {
747 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
748 		return;
749 	if (INODE_VERSION(inode) == MINIX_V1)
750 		V1_minix_truncate(inode);
751 	else
752 		V2_minix_truncate(inode);
753 }
754 
755 static struct file_system_type minix_fs_type = {
756 	.owner			= THIS_MODULE,
757 	.name			= "minix",
758 	.kill_sb		= kill_block_super,
759 	.fs_flags		= FS_REQUIRES_DEV,
760 	.init_fs_context	= minix_init_fs_context,
761 };
762 MODULE_ALIAS_FS("minix");
763 
764 static int __init init_minix_fs(void)
765 {
766 	int err = init_inodecache();
767 	if (err)
768 		goto out1;
769 	err = register_filesystem(&minix_fs_type);
770 	if (err)
771 		goto out;
772 	return 0;
773 out:
774 	destroy_inodecache();
775 out1:
776 	return err;
777 }
778 
779 static void __exit exit_minix_fs(void)
780 {
781         unregister_filesystem(&minix_fs_type);
782 	destroy_inodecache();
783 }
784 
785 module_init(init_minix_fs)
786 module_exit(exit_minix_fs)
787 MODULE_DESCRIPTION("Minix file system");
788 MODULE_LICENSE("GPL");
789 
790