xref: /kernel/linux/linux-6.6/fs/bfs/inode.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *	fs/bfs/inode.c
4 *	BFS superblock and inode operations.
5 *	Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
6 *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
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 <linux/uaccess.h>
20#include "bfs.h"
21
22MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
23MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
24MODULE_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
34struct 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_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);
86	inode->i_atime.tv_nsec = 0;
87	inode->i_mtime.tv_nsec = 0;
88
89	brelse(bh);
90	unlock_new_inode(inode);
91	return inode;
92
93error:
94	iget_failed(inode);
95	return ERR_PTR(-EIO);
96}
97
98static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
99{
100	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
101		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
102		return ERR_PTR(-EIO);
103	}
104
105	ino -= BFS_ROOT_INO;
106
107	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
108	if (!*p) {
109		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
110		return ERR_PTR(-EIO);
111	}
112
113	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
114}
115
116static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
117{
118	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
119	unsigned int ino = (u16)inode->i_ino;
120	unsigned long i_sblock;
121	struct bfs_inode *di;
122	struct buffer_head *bh;
123	int err = 0;
124
125	dprintf("ino=%08x\n", ino);
126
127	di = find_inode(inode->i_sb, ino, &bh);
128	if (IS_ERR(di))
129		return PTR_ERR(di);
130
131	mutex_lock(&info->bfs_lock);
132
133	if (ino == BFS_ROOT_INO)
134		di->i_vtype = cpu_to_le32(BFS_VDIR);
135	else
136		di->i_vtype = cpu_to_le32(BFS_VREG);
137
138	di->i_ino = cpu_to_le16(ino);
139	di->i_mode = cpu_to_le32(inode->i_mode);
140	di->i_uid = cpu_to_le32(i_uid_read(inode));
141	di->i_gid = cpu_to_le32(i_gid_read(inode));
142	di->i_nlink = cpu_to_le32(inode->i_nlink);
143	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
144	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
145	di->i_ctime = cpu_to_le32(inode_get_ctime(inode).tv_sec);
146	i_sblock = BFS_I(inode)->i_sblock;
147	di->i_sblock = cpu_to_le32(i_sblock);
148	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
149	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
150
151	mark_buffer_dirty(bh);
152	if (wbc->sync_mode == WB_SYNC_ALL) {
153		sync_dirty_buffer(bh);
154		if (buffer_req(bh) && !buffer_uptodate(bh))
155			err = -EIO;
156	}
157	brelse(bh);
158	mutex_unlock(&info->bfs_lock);
159	return err;
160}
161
162static void bfs_evict_inode(struct inode *inode)
163{
164	unsigned long ino = inode->i_ino;
165	struct bfs_inode *di;
166	struct buffer_head *bh;
167	struct super_block *s = inode->i_sb;
168	struct bfs_sb_info *info = BFS_SB(s);
169	struct bfs_inode_info *bi = BFS_I(inode);
170
171	dprintf("ino=%08lx\n", ino);
172
173	truncate_inode_pages_final(&inode->i_data);
174	invalidate_inode_buffers(inode);
175	clear_inode(inode);
176
177	if (inode->i_nlink)
178		return;
179
180	di = find_inode(s, inode->i_ino, &bh);
181	if (IS_ERR(di))
182		return;
183
184	mutex_lock(&info->bfs_lock);
185	/* clear on-disk inode */
186	memset(di, 0, sizeof(struct bfs_inode));
187	mark_buffer_dirty(bh);
188	brelse(bh);
189
190	if (bi->i_dsk_ino) {
191		if (bi->i_sblock)
192			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
193		info->si_freei++;
194		clear_bit(ino, info->si_imap);
195		bfs_dump_imap("evict_inode", s);
196	}
197
198	/*
199	 * If this was the last file, make the previous block
200	 * "last block of the last file" even if there is no
201	 * real file there, saves us 1 gap.
202	 */
203	if (info->si_lf_eblk == bi->i_eblock)
204		info->si_lf_eblk = bi->i_sblock - 1;
205	mutex_unlock(&info->bfs_lock);
206}
207
208static void bfs_put_super(struct super_block *s)
209{
210	struct bfs_sb_info *info = BFS_SB(s);
211
212	if (!info)
213		return;
214
215	mutex_destroy(&info->bfs_lock);
216	kfree(info);
217	s->s_fs_info = NULL;
218}
219
220static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
221{
222	struct super_block *s = dentry->d_sb;
223	struct bfs_sb_info *info = BFS_SB(s);
224	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
225	buf->f_type = BFS_MAGIC;
226	buf->f_bsize = s->s_blocksize;
227	buf->f_blocks = info->si_blocks;
228	buf->f_bfree = buf->f_bavail = info->si_freeb;
229	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
230	buf->f_ffree = info->si_freei;
231	buf->f_fsid = u64_to_fsid(id);
232	buf->f_namelen = BFS_NAMELEN;
233	return 0;
234}
235
236static struct kmem_cache *bfs_inode_cachep;
237
238static struct inode *bfs_alloc_inode(struct super_block *sb)
239{
240	struct bfs_inode_info *bi;
241	bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
242	if (!bi)
243		return NULL;
244	return &bi->vfs_inode;
245}
246
247static void bfs_free_inode(struct inode *inode)
248{
249	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
250}
251
252static void init_once(void *foo)
253{
254	struct bfs_inode_info *bi = foo;
255
256	inode_init_once(&bi->vfs_inode);
257}
258
259static int __init init_inodecache(void)
260{
261	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
262					     sizeof(struct bfs_inode_info),
263					     0, (SLAB_RECLAIM_ACCOUNT|
264						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
265					     init_once);
266	if (bfs_inode_cachep == NULL)
267		return -ENOMEM;
268	return 0;
269}
270
271static void destroy_inodecache(void)
272{
273	/*
274	 * Make sure all delayed rcu free inodes are flushed before we
275	 * destroy cache.
276	 */
277	rcu_barrier();
278	kmem_cache_destroy(bfs_inode_cachep);
279}
280
281static const struct super_operations bfs_sops = {
282	.alloc_inode	= bfs_alloc_inode,
283	.free_inode	= bfs_free_inode,
284	.write_inode	= bfs_write_inode,
285	.evict_inode	= bfs_evict_inode,
286	.put_super	= bfs_put_super,
287	.statfs		= bfs_statfs,
288};
289
290void bfs_dump_imap(const char *prefix, struct super_block *s)
291{
292#ifdef DEBUG
293	int i;
294	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
295
296	if (!tmpbuf)
297		return;
298	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
299		if (i > PAGE_SIZE - 100) break;
300		if (test_bit(i, BFS_SB(s)->si_imap))
301			strcat(tmpbuf, "1");
302		else
303			strcat(tmpbuf, "0");
304	}
305	printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
306	free_page((unsigned long)tmpbuf);
307#endif
308}
309
310static int bfs_fill_super(struct super_block *s, void *data, int silent)
311{
312	struct buffer_head *bh, *sbh;
313	struct bfs_super_block *bfs_sb;
314	struct inode *inode;
315	unsigned i;
316	struct bfs_sb_info *info;
317	int ret = -EINVAL;
318	unsigned long i_sblock, i_eblock, i_eoff, s_size;
319
320	info = kzalloc(sizeof(*info), GFP_KERNEL);
321	if (!info)
322		return -ENOMEM;
323	mutex_init(&info->bfs_lock);
324	s->s_fs_info = info;
325	s->s_time_min = 0;
326	s->s_time_max = U32_MAX;
327
328	sb_set_blocksize(s, BFS_BSIZE);
329
330	sbh = sb_bread(s, 0);
331	if (!sbh)
332		goto out;
333	bfs_sb = (struct bfs_super_block *)sbh->b_data;
334	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
335		if (!silent)
336			printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
337		goto out1;
338	}
339	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
340		printf("%s is unclean, continuing\n", s->s_id);
341
342	s->s_magic = BFS_MAGIC;
343
344	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
345	    le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
346		printf("Superblock is corrupted on %s\n", s->s_id);
347		goto out1;
348	}
349
350	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
351	if (info->si_lasti == BFS_MAX_LASTI)
352		printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
353	else if (info->si_lasti > BFS_MAX_LASTI) {
354		printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
355		goto out1;
356	}
357	for (i = 0; i < BFS_ROOT_INO; i++)
358		set_bit(i, info->si_imap);
359
360	s->s_op = &bfs_sops;
361	inode = bfs_iget(s, BFS_ROOT_INO);
362	if (IS_ERR(inode)) {
363		ret = PTR_ERR(inode);
364		goto out1;
365	}
366	s->s_root = d_make_root(inode);
367	if (!s->s_root) {
368		ret = -ENOMEM;
369		goto out1;
370	}
371
372	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
373	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
374	info->si_freei = 0;
375	info->si_lf_eblk = 0;
376
377	/* can we read the last block? */
378	bh = sb_bread(s, info->si_blocks - 1);
379	if (!bh) {
380		printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
381		ret = -EIO;
382		goto out2;
383	}
384	brelse(bh);
385
386	bh = NULL;
387	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
388		struct bfs_inode *di;
389		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
390		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
391		unsigned long eblock;
392
393		if (!off) {
394			brelse(bh);
395			bh = sb_bread(s, block);
396		}
397
398		if (!bh)
399			continue;
400
401		di = (struct bfs_inode *)bh->b_data + off;
402
403		/* test if filesystem is not corrupted */
404
405		i_eoff = le32_to_cpu(di->i_eoffset);
406		i_sblock = le32_to_cpu(di->i_sblock);
407		i_eblock = le32_to_cpu(di->i_eblock);
408		s_size = le32_to_cpu(bfs_sb->s_end);
409
410		if (i_sblock > info->si_blocks ||
411			i_eblock > info->si_blocks ||
412			i_sblock > i_eblock ||
413			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
414			i_sblock * BFS_BSIZE > i_eoff) {
415
416			printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
417
418			brelse(bh);
419			ret = -EIO;
420			goto out2;
421		}
422
423		if (!di->i_ino) {
424			info->si_freei++;
425			continue;
426		}
427		set_bit(i, info->si_imap);
428		info->si_freeb -= BFS_FILEBLOCKS(di);
429
430		eblock =  le32_to_cpu(di->i_eblock);
431		if (eblock > info->si_lf_eblk)
432			info->si_lf_eblk = eblock;
433	}
434	brelse(bh);
435	brelse(sbh);
436	bfs_dump_imap("fill_super", s);
437	return 0;
438
439out2:
440	dput(s->s_root);
441	s->s_root = NULL;
442out1:
443	brelse(sbh);
444out:
445	mutex_destroy(&info->bfs_lock);
446	kfree(info);
447	s->s_fs_info = NULL;
448	return ret;
449}
450
451static struct dentry *bfs_mount(struct file_system_type *fs_type,
452	int flags, const char *dev_name, void *data)
453{
454	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
455}
456
457static struct file_system_type bfs_fs_type = {
458	.owner		= THIS_MODULE,
459	.name		= "bfs",
460	.mount		= bfs_mount,
461	.kill_sb	= kill_block_super,
462	.fs_flags	= FS_REQUIRES_DEV,
463};
464MODULE_ALIAS_FS("bfs");
465
466static int __init init_bfs_fs(void)
467{
468	int err = init_inodecache();
469	if (err)
470		goto out1;
471	err = register_filesystem(&bfs_fs_type);
472	if (err)
473		goto out;
474	return 0;
475out:
476	destroy_inodecache();
477out1:
478	return err;
479}
480
481static void __exit exit_bfs_fs(void)
482{
483	unregister_filesystem(&bfs_fs_type);
484	destroy_inodecache();
485}
486
487module_init(init_bfs_fs)
488module_exit(exit_bfs_fs)
489