1/*
2 *	fs/bfs/inode.c
3 *	BFS superblock and inode operations.
4 *	Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5 *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
6 *
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 <asm/uaccess.h>
19#include "bfs.h"
20
21MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
22MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
23MODULE_LICENSE("GPL");
24
25#undef DEBUG
26
27#ifdef DEBUG
28#define dprintf(x...)	printf(x)
29#else
30#define dprintf(x...)
31#endif
32
33struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
34{
35	struct bfs_inode *di;
36	struct inode *inode;
37	struct buffer_head *bh;
38	int block, off;
39
40	inode = iget_locked(sb, ino);
41	if (!inode)
42		return ERR_PTR(-ENOMEM);
43	if (!(inode->i_state & I_NEW))
44		return inode;
45
46	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
47		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
48		goto error;
49	}
50
51	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
52	bh = sb_bread(inode->i_sb, block);
53	if (!bh) {
54		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
55									ino);
56		goto error;
57	}
58
59	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
60	di = (struct bfs_inode *)bh->b_data + off;
61
62	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
63	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
64		inode->i_mode |= S_IFDIR;
65		inode->i_op = &bfs_dir_inops;
66		inode->i_fop = &bfs_dir_operations;
67	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
68		inode->i_mode |= S_IFREG;
69		inode->i_op = &bfs_file_inops;
70		inode->i_fop = &bfs_file_operations;
71		inode->i_mapping->a_ops = &bfs_aops;
72	}
73
74	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
75	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
76	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
77	i_uid_write(inode, le32_to_cpu(di->i_uid));
78	i_gid_write(inode,  le32_to_cpu(di->i_gid));
79	set_nlink(inode, le32_to_cpu(di->i_nlink));
80	inode->i_size = BFS_FILESIZE(di);
81	inode->i_blocks = BFS_FILEBLOCKS(di);
82	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
83	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
84	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
85	inode->i_atime.tv_nsec = 0;
86	inode->i_mtime.tv_nsec = 0;
87	inode->i_ctime.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->i_ctime.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("delete_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->si_imap);
217	kfree(info);
218	s->s_fs_info = NULL;
219}
220
221static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
222{
223	struct super_block *s = dentry->d_sb;
224	struct bfs_sb_info *info = BFS_SB(s);
225	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
226	buf->f_type = BFS_MAGIC;
227	buf->f_bsize = s->s_blocksize;
228	buf->f_blocks = info->si_blocks;
229	buf->f_bfree = buf->f_bavail = info->si_freeb;
230	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
231	buf->f_ffree = info->si_freei;
232	buf->f_fsid.val[0] = (u32)id;
233	buf->f_fsid.val[1] = (u32)(id >> 32);
234	buf->f_namelen = BFS_NAMELEN;
235	return 0;
236}
237
238static struct kmem_cache *bfs_inode_cachep;
239
240static struct inode *bfs_alloc_inode(struct super_block *sb)
241{
242	struct bfs_inode_info *bi;
243	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
244	if (!bi)
245		return NULL;
246	return &bi->vfs_inode;
247}
248
249static void bfs_i_callback(struct rcu_head *head)
250{
251	struct inode *inode = container_of(head, struct inode, i_rcu);
252	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
253}
254
255static void bfs_destroy_inode(struct inode *inode)
256{
257	call_rcu(&inode->i_rcu, bfs_i_callback);
258}
259
260static void init_once(void *foo)
261{
262	struct bfs_inode_info *bi = foo;
263
264	inode_init_once(&bi->vfs_inode);
265}
266
267static int __init init_inodecache(void)
268{
269	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
270					     sizeof(struct bfs_inode_info),
271					     0, (SLAB_RECLAIM_ACCOUNT|
272						SLAB_MEM_SPREAD),
273					     init_once);
274	if (bfs_inode_cachep == NULL)
275		return -ENOMEM;
276	return 0;
277}
278
279static void destroy_inodecache(void)
280{
281	/*
282	 * Make sure all delayed rcu free inodes are flushed before we
283	 * destroy cache.
284	 */
285	rcu_barrier();
286	kmem_cache_destroy(bfs_inode_cachep);
287}
288
289static const struct super_operations bfs_sops = {
290	.alloc_inode	= bfs_alloc_inode,
291	.destroy_inode	= bfs_destroy_inode,
292	.write_inode	= bfs_write_inode,
293	.evict_inode	= bfs_evict_inode,
294	.put_super	= bfs_put_super,
295	.statfs		= bfs_statfs,
296};
297
298void bfs_dump_imap(const char *prefix, struct super_block *s)
299{
300#ifdef DEBUG
301	int i;
302	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
303
304	if (!tmpbuf)
305		return;
306	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
307		if (i > PAGE_SIZE - 100) break;
308		if (test_bit(i, BFS_SB(s)->si_imap))
309			strcat(tmpbuf, "1");
310		else
311			strcat(tmpbuf, "0");
312	}
313	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
314				prefix, BFS_SB(s)->si_lasti, tmpbuf);
315	free_page((unsigned long)tmpbuf);
316#endif
317}
318
319static int bfs_fill_super(struct super_block *s, void *data, int silent)
320{
321	struct buffer_head *bh, *sbh;
322	struct bfs_super_block *bfs_sb;
323	struct inode *inode;
324	unsigned i, imap_len;
325	struct bfs_sb_info *info;
326	int ret = -EINVAL;
327	unsigned long i_sblock, i_eblock, i_eoff, s_size;
328
329	info = kzalloc(sizeof(*info), GFP_KERNEL);
330	if (!info)
331		return -ENOMEM;
332	mutex_init(&info->bfs_lock);
333	s->s_fs_info = info;
334
335	sb_set_blocksize(s, BFS_BSIZE);
336
337	sbh = sb_bread(s, 0);
338	if (!sbh)
339		goto out;
340	bfs_sb = (struct bfs_super_block *)sbh->b_data;
341	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
342		if (!silent)
343			printf("No BFS filesystem on %s (magic=%08x)\n",
344				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
345		goto out1;
346	}
347	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
348		printf("%s is unclean, continuing\n", s->s_id);
349
350	s->s_magic = BFS_MAGIC;
351
352	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
353		printf("Superblock is corrupted\n");
354		goto out1;
355	}
356
357	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
358					sizeof(struct bfs_inode)
359					+ BFS_ROOT_INO - 1;
360	imap_len = (info->si_lasti / 8) + 1;
361	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
362	if (!info->si_imap)
363		goto out1;
364	for (i = 0; i < BFS_ROOT_INO; i++)
365		set_bit(i, info->si_imap);
366
367	s->s_op = &bfs_sops;
368	inode = bfs_iget(s, BFS_ROOT_INO);
369	if (IS_ERR(inode)) {
370		ret = PTR_ERR(inode);
371		goto out2;
372	}
373	s->s_root = d_make_root(inode);
374	if (!s->s_root) {
375		ret = -ENOMEM;
376		goto out2;
377	}
378
379	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
380	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
381			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
382	info->si_freei = 0;
383	info->si_lf_eblk = 0;
384
385	/* can we read the last block? */
386	bh = sb_bread(s, info->si_blocks - 1);
387	if (!bh) {
388		printf("Last block not available: %lu\n", info->si_blocks - 1);
389		ret = -EIO;
390		goto out3;
391	}
392	brelse(bh);
393
394	bh = NULL;
395	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
396		struct bfs_inode *di;
397		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
398		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
399		unsigned long eblock;
400
401		if (!off) {
402			brelse(bh);
403			bh = sb_bread(s, block);
404		}
405
406		if (!bh)
407			continue;
408
409		di = (struct bfs_inode *)bh->b_data + off;
410
411		/* test if filesystem is not corrupted */
412
413		i_eoff = le32_to_cpu(di->i_eoffset);
414		i_sblock = le32_to_cpu(di->i_sblock);
415		i_eblock = le32_to_cpu(di->i_eblock);
416		s_size = le32_to_cpu(bfs_sb->s_end);
417
418		if (i_sblock > info->si_blocks ||
419			i_eblock > info->si_blocks ||
420			i_sblock > i_eblock ||
421			i_eoff > s_size ||
422			i_sblock * BFS_BSIZE > i_eoff) {
423
424			printf("Inode 0x%08x corrupted\n", i);
425
426			brelse(bh);
427			ret = -EIO;
428			goto out3;
429		}
430
431		if (!di->i_ino) {
432			info->si_freei++;
433			continue;
434		}
435		set_bit(i, info->si_imap);
436		info->si_freeb -= BFS_FILEBLOCKS(di);
437
438		eblock =  le32_to_cpu(di->i_eblock);
439		if (eblock > info->si_lf_eblk)
440			info->si_lf_eblk = eblock;
441	}
442	brelse(bh);
443	brelse(sbh);
444	bfs_dump_imap("read_super", s);
445	return 0;
446
447out3:
448	dput(s->s_root);
449	s->s_root = NULL;
450out2:
451	kfree(info->si_imap);
452out1:
453	brelse(sbh);
454out:
455	mutex_destroy(&info->bfs_lock);
456	kfree(info);
457	s->s_fs_info = NULL;
458	return ret;
459}
460
461static struct dentry *bfs_mount(struct file_system_type *fs_type,
462	int flags, const char *dev_name, void *data)
463{
464	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
465}
466
467static struct file_system_type bfs_fs_type = {
468	.owner		= THIS_MODULE,
469	.name		= "bfs",
470	.mount		= bfs_mount,
471	.kill_sb	= kill_block_super,
472	.fs_flags	= FS_REQUIRES_DEV,
473};
474MODULE_ALIAS_FS("bfs");
475
476static int __init init_bfs_fs(void)
477{
478	int err = init_inodecache();
479	if (err)
480		goto out1;
481        err = register_filesystem(&bfs_fs_type);
482	if (err)
483		goto out;
484	return 0;
485out:
486	destroy_inodecache();
487out1:
488	return err;
489}
490
491static void __exit exit_bfs_fs(void)
492{
493	unregister_filesystem(&bfs_fs_type);
494	destroy_inodecache();
495}
496
497module_init(init_bfs_fs)
498module_exit(exit_bfs_fs)
499