xref: /linux/fs/minix/inode.c (revision 7879d7aff0ffd969fcb1a59e3f87ebb353e47b7f)
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_statfs(struct dentry *dentry, struct kstatfs *buf);
28 
minix_evict_inode(struct inode * inode)29 static void minix_evict_inode(struct inode *inode)
30 {
31 	truncate_inode_pages_final(&inode->i_data);
32 	if (!inode->i_nlink) {
33 		inode->i_size = 0;
34 		minix_truncate(inode);
35 	}
36 	invalidate_inode_buffers(inode);
37 	clear_inode(inode);
38 	if (!inode->i_nlink)
39 		minix_free_inode(inode);
40 }
41 
minix_put_super(struct super_block * sb)42 static void minix_put_super(struct super_block *sb)
43 {
44 	int i;
45 	struct minix_sb_info *sbi = minix_sb(sb);
46 
47 	if (!sb_rdonly(sb)) {
48 		if (sbi->s_version != MINIX_V3)	 /* s_state is now out from V3 sb */
49 			sbi->s_ms->s_state = sbi->s_mount_state;
50 		mark_buffer_dirty(sbi->s_sbh);
51 	}
52 	for (i = 0; i < sbi->s_imap_blocks; i++)
53 		brelse(sbi->s_imap[i]);
54 	for (i = 0; i < sbi->s_zmap_blocks; i++)
55 		brelse(sbi->s_zmap[i]);
56 	brelse (sbi->s_sbh);
57 	kfree(sbi->s_imap);
58 	sb->s_fs_info = NULL;
59 	kfree(sbi);
60 }
61 
62 static struct kmem_cache * minix_inode_cachep;
63 
minix_alloc_inode(struct super_block * sb)64 static struct inode *minix_alloc_inode(struct super_block *sb)
65 {
66 	struct minix_inode_info *ei;
67 	ei = alloc_inode_sb(sb, minix_inode_cachep, GFP_KERNEL);
68 	if (!ei)
69 		return NULL;
70 	return &ei->vfs_inode;
71 }
72 
minix_free_in_core_inode(struct inode * inode)73 static void minix_free_in_core_inode(struct inode *inode)
74 {
75 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
76 }
77 
init_once(void * foo)78 static void init_once(void *foo)
79 {
80 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
81 
82 	inode_init_once(&ei->vfs_inode);
83 }
84 
init_inodecache(void)85 static int __init init_inodecache(void)
86 {
87 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
88 					     sizeof(struct minix_inode_info),
89 					     0, (SLAB_RECLAIM_ACCOUNT|
90 						SLAB_ACCOUNT),
91 					     init_once);
92 	if (minix_inode_cachep == NULL)
93 		return -ENOMEM;
94 	return 0;
95 }
96 
destroy_inodecache(void)97 static void destroy_inodecache(void)
98 {
99 	/*
100 	 * Make sure all delayed rcu free inodes are flushed before we
101 	 * destroy cache.
102 	 */
103 	rcu_barrier();
104 	kmem_cache_destroy(minix_inode_cachep);
105 }
106 
107 static const struct super_operations minix_sops = {
108 	.alloc_inode	= minix_alloc_inode,
109 	.free_inode	= minix_free_in_core_inode,
110 	.write_inode	= minix_write_inode,
111 	.evict_inode	= minix_evict_inode,
112 	.put_super	= minix_put_super,
113 	.statfs		= minix_statfs,
114 };
115 
minix_reconfigure(struct fs_context * fc)116 static int minix_reconfigure(struct fs_context *fc)
117 {
118 	struct minix_super_block * ms;
119 	struct super_block *sb = fc->root->d_sb;
120 	struct minix_sb_info * sbi = sb->s_fs_info;
121 
122 	sync_filesystem(sb);
123 	ms = sbi->s_ms;
124 	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
125 		return 0;
126 	if (fc->sb_flags & SB_RDONLY) {
127 		if (ms->s_state & MINIX_VALID_FS ||
128 		    !(sbi->s_mount_state & MINIX_VALID_FS))
129 			return 0;
130 		/* Mounting a rw partition read-only. */
131 		if (sbi->s_version != MINIX_V3)
132 			ms->s_state = sbi->s_mount_state;
133 		mark_buffer_dirty(sbi->s_sbh);
134 	} else {
135 	  	/* Mount a partition which is read-only, read-write. */
136 		if (sbi->s_version != MINIX_V3) {
137 			sbi->s_mount_state = ms->s_state;
138 			ms->s_state &= ~MINIX_VALID_FS;
139 		} else {
140 			sbi->s_mount_state = MINIX_VALID_FS;
141 		}
142 		mark_buffer_dirty(sbi->s_sbh);
143 
144 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
145 			printk("MINIX-fs warning: remounting unchecked fs, "
146 				"running fsck is recommended\n");
147 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
148 			printk("MINIX-fs warning: remounting fs with errors, "
149 				"running fsck is recommended\n");
150 	}
151 	return 0;
152 }
153 
minix_check_superblock(struct super_block * sb)154 static bool minix_check_superblock(struct super_block *sb)
155 {
156 	struct minix_sb_info *sbi = minix_sb(sb);
157 
158 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
159 		return false;
160 
161 	/*
162 	 * s_max_size must not exceed the block mapping limitation.  This check
163 	 * is only needed for V1 filesystems, since V2/V3 support an extra level
164 	 * of indirect blocks which places the limit well above U32_MAX.
165 	 */
166 	if (sbi->s_version == MINIX_V1 &&
167 	    sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE)
168 		return false;
169 
170 	return true;
171 }
172 
minix_fill_super(struct super_block * s,struct fs_context * fc)173 static int minix_fill_super(struct super_block *s, struct fs_context *fc)
174 {
175 	struct buffer_head *bh;
176 	struct buffer_head **map;
177 	struct minix_super_block *ms;
178 	struct minix3_super_block *m3s = NULL;
179 	unsigned long i, block;
180 	struct inode *root_inode;
181 	struct minix_sb_info *sbi;
182 	int ret = -EINVAL;
183 	int silent = fc->sb_flags & SB_SILENT;
184 
185 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
186 	if (!sbi)
187 		return -ENOMEM;
188 	s->s_fs_info = sbi;
189 
190 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
191 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
192 
193 	if (!sb_set_blocksize(s, BLOCK_SIZE))
194 		goto out_bad_hblock;
195 
196 	if (!(bh = sb_bread(s, 1)))
197 		goto out_bad_sb;
198 
199 	ms = (struct minix_super_block *) bh->b_data;
200 	sbi->s_ms = ms;
201 	sbi->s_sbh = bh;
202 	sbi->s_mount_state = ms->s_state;
203 	sbi->s_ninodes = ms->s_ninodes;
204 	sbi->s_nzones = ms->s_nzones;
205 	sbi->s_imap_blocks = ms->s_imap_blocks;
206 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
207 	sbi->s_firstdatazone = ms->s_firstdatazone;
208 	sbi->s_log_zone_size = ms->s_log_zone_size;
209 	s->s_maxbytes = ms->s_max_size;
210 	s->s_magic = ms->s_magic;
211 	if (s->s_magic == MINIX_SUPER_MAGIC) {
212 		sbi->s_version = MINIX_V1;
213 		sbi->s_dirsize = 16;
214 		sbi->s_namelen = 14;
215 		s->s_max_links = MINIX_LINK_MAX;
216 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
217 		sbi->s_version = MINIX_V1;
218 		sbi->s_dirsize = 32;
219 		sbi->s_namelen = 30;
220 		s->s_max_links = MINIX_LINK_MAX;
221 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
222 		sbi->s_version = MINIX_V2;
223 		sbi->s_nzones = ms->s_zones;
224 		sbi->s_dirsize = 16;
225 		sbi->s_namelen = 14;
226 		s->s_max_links = MINIX2_LINK_MAX;
227 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
228 		sbi->s_version = MINIX_V2;
229 		sbi->s_nzones = ms->s_zones;
230 		sbi->s_dirsize = 32;
231 		sbi->s_namelen = 30;
232 		s->s_max_links = MINIX2_LINK_MAX;
233 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
234 		m3s = (struct minix3_super_block *) bh->b_data;
235 		s->s_magic = m3s->s_magic;
236 		sbi->s_imap_blocks = m3s->s_imap_blocks;
237 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
238 		sbi->s_firstdatazone = m3s->s_firstdatazone;
239 		sbi->s_log_zone_size = m3s->s_log_zone_size;
240 		s->s_maxbytes = m3s->s_max_size;
241 		sbi->s_ninodes = m3s->s_ninodes;
242 		sbi->s_nzones = m3s->s_zones;
243 		sbi->s_dirsize = 64;
244 		sbi->s_namelen = 60;
245 		sbi->s_version = MINIX_V3;
246 		sbi->s_mount_state = MINIX_VALID_FS;
247 		sb_set_blocksize(s, m3s->s_blocksize);
248 		s->s_max_links = MINIX2_LINK_MAX;
249 	} else
250 		goto out_no_fs;
251 
252 	if (!minix_check_superblock(s))
253 		goto out_illegal_sb;
254 
255 	/*
256 	 * Allocate the buffer map to keep the superblock small.
257 	 */
258 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
259 	map = kzalloc(i, GFP_KERNEL);
260 	if (!map)
261 		goto out_no_map;
262 	sbi->s_imap = &map[0];
263 	sbi->s_zmap = &map[sbi->s_imap_blocks];
264 
265 	block=2;
266 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
267 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
268 			goto out_no_bitmap;
269 		block++;
270 	}
271 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
272 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
273 			goto out_no_bitmap;
274 		block++;
275 	}
276 
277 	minix_set_bit(0,sbi->s_imap[0]->b_data);
278 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
279 
280 	/* Apparently minix can create filesystems that allocate more blocks for
281 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
282 	 * create one with not enough blocks and bail out if so.
283 	 */
284 	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
285 	if (sbi->s_imap_blocks < block) {
286 		printk("MINIX-fs: file system does not have enough "
287 				"imap blocks allocated.  Refusing to mount.\n");
288 		goto out_no_bitmap;
289 	}
290 
291 	block = minix_blocks_needed(
292 			(sbi->s_nzones - sbi->s_firstdatazone + 1),
293 			s->s_blocksize);
294 	if (sbi->s_zmap_blocks < block) {
295 		printk("MINIX-fs: file system does not have enough "
296 				"zmap blocks allocated.  Refusing to mount.\n");
297 		goto out_no_bitmap;
298 	}
299 
300 	/* set up enough so that it can read an inode */
301 	s->s_op = &minix_sops;
302 	s->s_time_min = 0;
303 	s->s_time_max = U32_MAX;
304 	root_inode = minix_iget(s, MINIX_ROOT_INO);
305 	if (IS_ERR(root_inode)) {
306 		ret = PTR_ERR(root_inode);
307 		goto out_no_root;
308 	}
309 
310 	ret = -ENOMEM;
311 	s->s_root = d_make_root(root_inode);
312 	if (!s->s_root)
313 		goto out_no_root;
314 
315 	if (!sb_rdonly(s)) {
316 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
317 			ms->s_state &= ~MINIX_VALID_FS;
318 		mark_buffer_dirty(bh);
319 	}
320 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
321 		printk("MINIX-fs: mounting unchecked file system, "
322 			"running fsck is recommended\n");
323 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
324 		printk("MINIX-fs: mounting file system with errors, "
325 			"running fsck is recommended\n");
326 
327 	return 0;
328 
329 out_no_root:
330 	if (!silent)
331 		printk("MINIX-fs: get root inode failed\n");
332 	goto out_freemap;
333 
334 out_no_bitmap:
335 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
336 out_freemap:
337 	for (i = 0; i < sbi->s_imap_blocks; i++)
338 		brelse(sbi->s_imap[i]);
339 	for (i = 0; i < sbi->s_zmap_blocks; i++)
340 		brelse(sbi->s_zmap[i]);
341 	kfree(sbi->s_imap);
342 	goto out_release;
343 
344 out_no_map:
345 	ret = -ENOMEM;
346 	if (!silent)
347 		printk("MINIX-fs: can't allocate map\n");
348 	goto out_release;
349 
350 out_illegal_sb:
351 	if (!silent)
352 		printk("MINIX-fs: bad superblock\n");
353 	goto out_release;
354 
355 out_no_fs:
356 	if (!silent)
357 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
358 		       "on device %s.\n", s->s_id);
359 out_release:
360 	brelse(bh);
361 	goto out;
362 
363 out_bad_hblock:
364 	printk("MINIX-fs: blocksize too small for device\n");
365 	goto out;
366 
367 out_bad_sb:
368 	printk("MINIX-fs: unable to read superblock\n");
369 out:
370 	s->s_fs_info = NULL;
371 	kfree(sbi);
372 	return ret;
373 }
374 
minix_get_tree(struct fs_context * fc)375 static int minix_get_tree(struct fs_context *fc)
376 {
377 	 return get_tree_bdev(fc, minix_fill_super);
378 }
379 
380 static const struct fs_context_operations minix_context_ops = {
381 	.get_tree	= minix_get_tree,
382 	.reconfigure	= minix_reconfigure,
383 };
384 
minix_init_fs_context(struct fs_context * fc)385 static int minix_init_fs_context(struct fs_context *fc)
386 {
387 	fc->ops = &minix_context_ops;
388 
389 	return 0;
390 }
391 
minix_statfs(struct dentry * dentry,struct kstatfs * buf)392 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
393 {
394 	struct super_block *sb = dentry->d_sb;
395 	struct minix_sb_info *sbi = minix_sb(sb);
396 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
397 	buf->f_type = sb->s_magic;
398 	buf->f_bsize = sb->s_blocksize;
399 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
400 	buf->f_bfree = minix_count_free_blocks(sb);
401 	buf->f_bavail = buf->f_bfree;
402 	buf->f_files = sbi->s_ninodes;
403 	buf->f_ffree = minix_count_free_inodes(sb);
404 	buf->f_namelen = sbi->s_namelen;
405 	buf->f_fsid = u64_to_fsid(id);
406 
407 	return 0;
408 }
409 
minix_get_block(struct inode * inode,sector_t block,struct buffer_head * bh_result,int create)410 static int minix_get_block(struct inode *inode, sector_t block,
411 		    struct buffer_head *bh_result, int create)
412 {
413 	if (INODE_VERSION(inode) == MINIX_V1)
414 		return V1_minix_get_block(inode, block, bh_result, create);
415 	else
416 		return V2_minix_get_block(inode, block, bh_result, create);
417 }
418 
minix_writepages(struct address_space * mapping,struct writeback_control * wbc)419 static int minix_writepages(struct address_space *mapping,
420 		struct writeback_control *wbc)
421 {
422 	return mpage_writepages(mapping, wbc, minix_get_block);
423 }
424 
minix_read_folio(struct file * file,struct folio * folio)425 static int minix_read_folio(struct file *file, struct folio *folio)
426 {
427 	return block_read_full_folio(folio, minix_get_block);
428 }
429 
minix_prepare_chunk(struct folio * folio,loff_t pos,unsigned len)430 int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
431 {
432 	return __block_write_begin(folio, pos, len, minix_get_block);
433 }
434 
minix_write_failed(struct address_space * mapping,loff_t to)435 static void minix_write_failed(struct address_space *mapping, loff_t to)
436 {
437 	struct inode *inode = mapping->host;
438 
439 	if (to > inode->i_size) {
440 		truncate_pagecache(inode, inode->i_size);
441 		minix_truncate(inode);
442 	}
443 }
444 
minix_write_begin(const struct kiocb * iocb,struct address_space * mapping,loff_t pos,unsigned len,struct folio ** foliop,void ** fsdata)445 static int minix_write_begin(const struct kiocb *iocb,
446 			     struct address_space *mapping,
447 			     loff_t pos, unsigned len,
448 			     struct folio **foliop, void **fsdata)
449 {
450 	int ret;
451 
452 	ret = block_write_begin(mapping, pos, len, foliop, minix_get_block);
453 	if (unlikely(ret))
454 		minix_write_failed(mapping, pos + len);
455 
456 	return ret;
457 }
458 
minix_bmap(struct address_space * mapping,sector_t block)459 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
460 {
461 	return generic_block_bmap(mapping,block,minix_get_block);
462 }
463 
464 static const struct address_space_operations minix_aops = {
465 	.dirty_folio	= block_dirty_folio,
466 	.invalidate_folio = block_invalidate_folio,
467 	.read_folio = minix_read_folio,
468 	.writepages = minix_writepages,
469 	.write_begin = minix_write_begin,
470 	.write_end = generic_write_end,
471 	.migrate_folio = buffer_migrate_folio,
472 	.bmap = minix_bmap,
473 	.direct_IO = noop_direct_IO
474 };
475 
476 static const struct inode_operations minix_symlink_inode_operations = {
477 	.get_link	= page_get_link,
478 	.getattr	= minix_getattr,
479 };
480 
minix_set_inode(struct inode * inode,dev_t rdev)481 void minix_set_inode(struct inode *inode, dev_t rdev)
482 {
483 	if (S_ISREG(inode->i_mode)) {
484 		inode->i_op = &minix_file_inode_operations;
485 		inode->i_fop = &minix_file_operations;
486 		inode->i_mapping->a_ops = &minix_aops;
487 	} else if (S_ISDIR(inode->i_mode)) {
488 		inode->i_op = &minix_dir_inode_operations;
489 		inode->i_fop = &minix_dir_operations;
490 		inode->i_mapping->a_ops = &minix_aops;
491 	} else if (S_ISLNK(inode->i_mode)) {
492 		inode->i_op = &minix_symlink_inode_operations;
493 		inode_nohighmem(inode);
494 		inode->i_mapping->a_ops = &minix_aops;
495 	} else
496 		init_special_inode(inode, inode->i_mode, rdev);
497 }
498 
499 /*
500  * The minix V1 function to read an inode.
501  */
V1_minix_iget(struct inode * inode)502 static struct inode *V1_minix_iget(struct inode *inode)
503 {
504 	struct buffer_head * bh;
505 	struct minix_inode * raw_inode;
506 	struct minix_inode_info *minix_inode = minix_i(inode);
507 	int i;
508 
509 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
510 	if (!raw_inode) {
511 		iget_failed(inode);
512 		return ERR_PTR(-EIO);
513 	}
514 	if (raw_inode->i_nlinks == 0) {
515 		printk("MINIX-fs: deleted inode referenced: %lu\n",
516 		       inode->i_ino);
517 		brelse(bh);
518 		iget_failed(inode);
519 		return ERR_PTR(-ESTALE);
520 	}
521 	inode->i_mode = raw_inode->i_mode;
522 	i_uid_write(inode, raw_inode->i_uid);
523 	i_gid_write(inode, raw_inode->i_gid);
524 	set_nlink(inode, raw_inode->i_nlinks);
525 	inode->i_size = raw_inode->i_size;
526 	inode_set_mtime_to_ts(inode,
527 			      inode_set_atime_to_ts(inode, inode_set_ctime(inode, raw_inode->i_time, 0)));
528 	inode->i_blocks = 0;
529 	for (i = 0; i < 9; i++)
530 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
531 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
532 	brelse(bh);
533 	unlock_new_inode(inode);
534 	return inode;
535 }
536 
537 /*
538  * The minix V2 function to read an inode.
539  */
V2_minix_iget(struct inode * inode)540 static struct inode *V2_minix_iget(struct inode *inode)
541 {
542 	struct buffer_head * bh;
543 	struct minix2_inode * raw_inode;
544 	struct minix_inode_info *minix_inode = minix_i(inode);
545 	int i;
546 
547 	raw_inode = minix_V2_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: %lu\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(inode, raw_inode->i_mtime, 0);
565 	inode_set_atime(inode, raw_inode->i_atime, 0);
566 	inode_set_ctime(inode, raw_inode->i_ctime, 0);
567 	inode->i_blocks = 0;
568 	for (i = 0; i < 10; i++)
569 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
570 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
571 	brelse(bh);
572 	unlock_new_inode(inode);
573 	return inode;
574 }
575 
576 /*
577  * The global function to read an inode.
578  */
minix_iget(struct super_block * sb,unsigned long ino)579 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
580 {
581 	struct inode *inode;
582 
583 	inode = iget_locked(sb, ino);
584 	if (!inode)
585 		return ERR_PTR(-ENOMEM);
586 	if (!(inode->i_state & I_NEW))
587 		return inode;
588 
589 	if (INODE_VERSION(inode) == MINIX_V1)
590 		return V1_minix_iget(inode);
591 	else
592 		return V2_minix_iget(inode);
593 }
594 
595 /*
596  * The minix V1 function to synchronize an inode.
597  */
V1_minix_update_inode(struct inode * inode)598 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
599 {
600 	struct buffer_head * bh;
601 	struct minix_inode * raw_inode;
602 	struct minix_inode_info *minix_inode = minix_i(inode);
603 	int i;
604 
605 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
606 	if (!raw_inode)
607 		return NULL;
608 	raw_inode->i_mode = inode->i_mode;
609 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
610 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
611 	raw_inode->i_nlinks = inode->i_nlink;
612 	raw_inode->i_size = inode->i_size;
613 	raw_inode->i_time = inode_get_mtime_sec(inode);
614 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
615 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
616 	else for (i = 0; i < 9; i++)
617 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
618 	mark_buffer_dirty(bh);
619 	return bh;
620 }
621 
622 /*
623  * The minix V2 function to synchronize an inode.
624  */
V2_minix_update_inode(struct inode * inode)625 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
626 {
627 	struct buffer_head * bh;
628 	struct minix2_inode * raw_inode;
629 	struct minix_inode_info *minix_inode = minix_i(inode);
630 	int i;
631 
632 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
633 	if (!raw_inode)
634 		return NULL;
635 	raw_inode->i_mode = inode->i_mode;
636 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
637 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
638 	raw_inode->i_nlinks = inode->i_nlink;
639 	raw_inode->i_size = inode->i_size;
640 	raw_inode->i_mtime = inode_get_mtime_sec(inode);
641 	raw_inode->i_atime = inode_get_atime_sec(inode);
642 	raw_inode->i_ctime = inode_get_ctime_sec(inode);
643 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
644 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
645 	else for (i = 0; i < 10; i++)
646 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
647 	mark_buffer_dirty(bh);
648 	return bh;
649 }
650 
minix_write_inode(struct inode * inode,struct writeback_control * wbc)651 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
652 {
653 	int err = 0;
654 	struct buffer_head *bh;
655 
656 	if (INODE_VERSION(inode) == MINIX_V1)
657 		bh = V1_minix_update_inode(inode);
658 	else
659 		bh = V2_minix_update_inode(inode);
660 	if (!bh)
661 		return -EIO;
662 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
663 		sync_dirty_buffer(bh);
664 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
665 			printk("IO error syncing minix inode [%s:%08lx]\n",
666 				inode->i_sb->s_id, inode->i_ino);
667 			err = -EIO;
668 		}
669 	}
670 	brelse (bh);
671 	return err;
672 }
673 
minix_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)674 int minix_getattr(struct mnt_idmap *idmap, const struct path *path,
675 		  struct kstat *stat, u32 request_mask, unsigned int flags)
676 {
677 	struct super_block *sb = path->dentry->d_sb;
678 	struct inode *inode = d_inode(path->dentry);
679 
680 	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
681 	if (INODE_VERSION(inode) == MINIX_V1)
682 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
683 	else
684 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
685 	stat->blksize = sb->s_blocksize;
686 	return 0;
687 }
688 
689 /*
690  * The function that is called for file truncation.
691  */
minix_truncate(struct inode * inode)692 void minix_truncate(struct inode * inode)
693 {
694 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
695 		return;
696 	if (INODE_VERSION(inode) == MINIX_V1)
697 		V1_minix_truncate(inode);
698 	else
699 		V2_minix_truncate(inode);
700 }
701 
702 static struct file_system_type minix_fs_type = {
703 	.owner			= THIS_MODULE,
704 	.name			= "minix",
705 	.kill_sb		= kill_block_super,
706 	.fs_flags		= FS_REQUIRES_DEV,
707 	.init_fs_context	= minix_init_fs_context,
708 };
709 MODULE_ALIAS_FS("minix");
710 
init_minix_fs(void)711 static int __init init_minix_fs(void)
712 {
713 	int err = init_inodecache();
714 	if (err)
715 		goto out1;
716 	err = register_filesystem(&minix_fs_type);
717 	if (err)
718 		goto out;
719 	return 0;
720 out:
721 	destroy_inodecache();
722 out1:
723 	return err;
724 }
725 
exit_minix_fs(void)726 static void __exit exit_minix_fs(void)
727 {
728         unregister_filesystem(&minix_fs_type);
729 	destroy_inodecache();
730 }
731 
732 module_init(init_minix_fs)
733 module_exit(exit_minix_fs)
734 MODULE_DESCRIPTION("Minix file system");
735 MODULE_LICENSE("GPL");
736 
737