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