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/smp_lock.h>
16#include <linux/buffer_head.h>
17#include <linux/vfs.h>
18#include <linux/writeback.h>
19#include <asm/uaccess.h>
20#include "bfs.h"
21
22MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
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
34void dump_imap(const char *prefix, struct super_block *s);
35
36struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
37{
38	struct bfs_inode *di;
39	struct inode *inode;
40	struct buffer_head *bh;
41	int block, off;
42
43	inode = iget_locked(sb, ino);
44	if (IS_ERR(inode))
45		return ERR_PTR(-ENOMEM);
46	if (!(inode->i_state & I_NEW))
47		return inode;
48
49	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
50		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
51		goto error;
52	}
53
54	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
55	bh = sb_bread(inode->i_sb, block);
56	if (!bh) {
57		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
58									ino);
59		goto error;
60	}
61
62	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
63	di = (struct bfs_inode *)bh->b_data + off;
64
65	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
66	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
67		inode->i_mode |= S_IFDIR;
68		inode->i_op = &bfs_dir_inops;
69		inode->i_fop = &bfs_dir_operations;
70	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
71		inode->i_mode |= S_IFREG;
72		inode->i_op = &bfs_file_inops;
73		inode->i_fop = &bfs_file_operations;
74		inode->i_mapping->a_ops = &bfs_aops;
75	}
76
77	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
78	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
79	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
80	inode->i_uid =  le32_to_cpu(di->i_uid);
81	inode->i_gid =  le32_to_cpu(di->i_gid);
82	inode->i_nlink =  le32_to_cpu(di->i_nlink);
83	inode->i_size = BFS_FILESIZE(di);
84	inode->i_blocks = BFS_FILEBLOCKS(di);
85	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
86	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
87	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
88	inode->i_atime.tv_nsec = 0;
89	inode->i_mtime.tv_nsec = 0;
90	inode->i_ctime.tv_nsec = 0;
91
92	brelse(bh);
93	unlock_new_inode(inode);
94	return inode;
95
96error:
97	iget_failed(inode);
98	return ERR_PTR(-EIO);
99}
100
101static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
102{
103	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
104		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
105		return ERR_PTR(-EIO);
106	}
107
108	ino -= BFS_ROOT_INO;
109
110	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
111	if (!*p) {
112		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
113		return ERR_PTR(-EIO);
114	}
115
116	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
117}
118
119static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
120{
121	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
122	unsigned int ino = (u16)inode->i_ino;
123        unsigned long i_sblock;
124	struct bfs_inode *di;
125	struct buffer_head *bh;
126	int err = 0;
127
128        dprintf("ino=%08x\n", ino);
129
130	di = find_inode(inode->i_sb, ino, &bh);
131	if (IS_ERR(di))
132		return PTR_ERR(di);
133
134	mutex_lock(&info->bfs_lock);
135
136	if (ino == BFS_ROOT_INO)
137		di->i_vtype = cpu_to_le32(BFS_VDIR);
138	else
139		di->i_vtype = cpu_to_le32(BFS_VREG);
140
141	di->i_ino = cpu_to_le16(ino);
142	di->i_mode = cpu_to_le32(inode->i_mode);
143	di->i_uid = cpu_to_le32(inode->i_uid);
144	di->i_gid = cpu_to_le32(inode->i_gid);
145	di->i_nlink = cpu_to_le32(inode->i_nlink);
146	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
147	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
148	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
149        i_sblock = BFS_I(inode)->i_sblock;
150	di->i_sblock = cpu_to_le32(i_sblock);
151	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
152	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
153
154	mark_buffer_dirty(bh);
155	if (wbc->sync_mode == WB_SYNC_ALL) {
156		sync_dirty_buffer(bh);
157		if (buffer_req(bh) && !buffer_uptodate(bh))
158			err = -EIO;
159	}
160	brelse(bh);
161	mutex_unlock(&info->bfs_lock);
162	return err;
163}
164
165static void bfs_evict_inode(struct inode *inode)
166{
167	unsigned long ino = inode->i_ino;
168	struct bfs_inode *di;
169	struct buffer_head *bh;
170	struct super_block *s = inode->i_sb;
171	struct bfs_sb_info *info = BFS_SB(s);
172	struct bfs_inode_info *bi = BFS_I(inode);
173
174	dprintf("ino=%08lx\n", ino);
175
176	truncate_inode_pages(&inode->i_data, 0);
177	invalidate_inode_buffers(inode);
178	end_writeback(inode);
179
180	if (inode->i_nlink)
181		return;
182
183	di = find_inode(s, inode->i_ino, &bh);
184	if (IS_ERR(di))
185		return;
186
187	mutex_lock(&info->bfs_lock);
188	/* clear on-disk inode */
189	memset(di, 0, sizeof(struct bfs_inode));
190	mark_buffer_dirty(bh);
191	brelse(bh);
192
193        if (bi->i_dsk_ino) {
194		if (bi->i_sblock)
195			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
196		info->si_freei++;
197		clear_bit(ino, info->si_imap);
198		dump_imap("delete_inode", s);
199        }
200
201	/*
202	 * If this was the last file, make the previous block
203	 * "last block of the last file" even if there is no
204	 * real file there, saves us 1 gap.
205	 */
206	if (info->si_lf_eblk == bi->i_eblock)
207		info->si_lf_eblk = bi->i_sblock - 1;
208	mutex_unlock(&info->bfs_lock);
209}
210
211static void bfs_put_super(struct super_block *s)
212{
213	struct bfs_sb_info *info = BFS_SB(s);
214
215	if (!info)
216		return;
217
218	lock_kernel();
219
220	mutex_destroy(&info->bfs_lock);
221	kfree(info->si_imap);
222	kfree(info);
223	s->s_fs_info = NULL;
224
225	unlock_kernel();
226}
227
228static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
229{
230	struct super_block *s = dentry->d_sb;
231	struct bfs_sb_info *info = BFS_SB(s);
232	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
233	buf->f_type = BFS_MAGIC;
234	buf->f_bsize = s->s_blocksize;
235	buf->f_blocks = info->si_blocks;
236	buf->f_bfree = buf->f_bavail = info->si_freeb;
237	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
238	buf->f_ffree = info->si_freei;
239	buf->f_fsid.val[0] = (u32)id;
240	buf->f_fsid.val[1] = (u32)(id >> 32);
241	buf->f_namelen = BFS_NAMELEN;
242	return 0;
243}
244
245static struct kmem_cache *bfs_inode_cachep;
246
247static struct inode *bfs_alloc_inode(struct super_block *sb)
248{
249	struct bfs_inode_info *bi;
250	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
251	if (!bi)
252		return NULL;
253	return &bi->vfs_inode;
254}
255
256static void bfs_destroy_inode(struct inode *inode)
257{
258	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
259}
260
261static void init_once(void *foo)
262{
263	struct bfs_inode_info *bi = foo;
264
265	inode_init_once(&bi->vfs_inode);
266}
267
268static int init_inodecache(void)
269{
270	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
271					     sizeof(struct bfs_inode_info),
272					     0, (SLAB_RECLAIM_ACCOUNT|
273						SLAB_MEM_SPREAD),
274					     init_once);
275	if (bfs_inode_cachep == NULL)
276		return -ENOMEM;
277	return 0;
278}
279
280static void destroy_inodecache(void)
281{
282	kmem_cache_destroy(bfs_inode_cachep);
283}
284
285static const struct super_operations bfs_sops = {
286	.alloc_inode	= bfs_alloc_inode,
287	.destroy_inode	= bfs_destroy_inode,
288	.write_inode	= bfs_write_inode,
289	.evict_inode	= bfs_evict_inode,
290	.put_super	= bfs_put_super,
291	.statfs		= bfs_statfs,
292};
293
294void dump_imap(const char *prefix, struct super_block *s)
295{
296#ifdef DEBUG
297	int i;
298	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
299
300	if (!tmpbuf)
301		return;
302	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
303		if (i > PAGE_SIZE - 100) break;
304		if (test_bit(i, BFS_SB(s)->si_imap))
305			strcat(tmpbuf, "1");
306		else
307			strcat(tmpbuf, "0");
308	}
309	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
310				prefix, BFS_SB(s)->si_lasti, tmpbuf);
311	free_page((unsigned long)tmpbuf);
312#endif
313}
314
315static int bfs_fill_super(struct super_block *s, void *data, int silent)
316{
317	struct buffer_head *bh, *sbh;
318	struct bfs_super_block *bfs_sb;
319	struct inode *inode;
320	unsigned i, imap_len;
321	struct bfs_sb_info *info;
322	int ret = -EINVAL;
323	unsigned long i_sblock, i_eblock, i_eoff, s_size;
324
325	info = kzalloc(sizeof(*info), GFP_KERNEL);
326	if (!info)
327		return -ENOMEM;
328	mutex_init(&info->bfs_lock);
329	s->s_fs_info = info;
330
331	sb_set_blocksize(s, BFS_BSIZE);
332
333	sbh = sb_bread(s, 0);
334	if (!sbh)
335		goto out;
336	bfs_sb = (struct bfs_super_block *)sbh->b_data;
337	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
338		if (!silent)
339			printf("No BFS filesystem on %s (magic=%08x)\n",
340				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
341		goto out1;
342	}
343	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
344		printf("%s is unclean, continuing\n", s->s_id);
345
346	s->s_magic = BFS_MAGIC;
347
348	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
349		printf("Superblock is corrupted\n");
350		goto out1;
351	}
352
353	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
354					sizeof(struct bfs_inode)
355					+ BFS_ROOT_INO - 1;
356	imap_len = (info->si_lasti / 8) + 1;
357	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
358	if (!info->si_imap)
359		goto out1;
360	for (i = 0; i < BFS_ROOT_INO; i++)
361		set_bit(i, info->si_imap);
362
363	s->s_op = &bfs_sops;
364	inode = bfs_iget(s, BFS_ROOT_INO);
365	if (IS_ERR(inode)) {
366		ret = PTR_ERR(inode);
367		goto out2;
368	}
369	s->s_root = d_alloc_root(inode);
370	if (!s->s_root) {
371		iput(inode);
372		ret = -ENOMEM;
373		goto out2;
374	}
375
376	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
377	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
378			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
379	info->si_freei = 0;
380	info->si_lf_eblk = 0;
381
382	/* can we read the last block? */
383	bh = sb_bread(s, info->si_blocks - 1);
384	if (!bh) {
385		printf("Last block not available: %lu\n", info->si_blocks - 1);
386		ret = -EIO;
387		goto out3;
388	}
389	brelse(bh);
390
391	bh = NULL;
392	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
393		struct bfs_inode *di;
394		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
395		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
396		unsigned long eblock;
397
398		if (!off) {
399			brelse(bh);
400			bh = sb_bread(s, block);
401		}
402
403		if (!bh)
404			continue;
405
406		di = (struct bfs_inode *)bh->b_data + off;
407
408		/* test if filesystem is not corrupted */
409
410		i_eoff = le32_to_cpu(di->i_eoffset);
411		i_sblock = le32_to_cpu(di->i_sblock);
412		i_eblock = le32_to_cpu(di->i_eblock);
413		s_size = le32_to_cpu(bfs_sb->s_end);
414
415		if (i_sblock > info->si_blocks ||
416			i_eblock > info->si_blocks ||
417			i_sblock > i_eblock ||
418			i_eoff > s_size ||
419			i_sblock * BFS_BSIZE > i_eoff) {
420
421			printf("Inode 0x%08x corrupted\n", i);
422
423			brelse(bh);
424			ret = -EIO;
425			goto out3;
426		}
427
428		if (!di->i_ino) {
429			info->si_freei++;
430			continue;
431		}
432		set_bit(i, info->si_imap);
433		info->si_freeb -= BFS_FILEBLOCKS(di);
434
435		eblock =  le32_to_cpu(di->i_eblock);
436		if (eblock > info->si_lf_eblk)
437			info->si_lf_eblk = eblock;
438	}
439	brelse(bh);
440	brelse(sbh);
441	dump_imap("read_super", s);
442	return 0;
443
444out3:
445	dput(s->s_root);
446	s->s_root = NULL;
447out2:
448	kfree(info->si_imap);
449out1:
450	brelse(sbh);
451out:
452	mutex_destroy(&info->bfs_lock);
453	kfree(info);
454	s->s_fs_info = NULL;
455	return ret;
456}
457
458static int bfs_get_sb(struct file_system_type *fs_type,
459	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
460{
461	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
462}
463
464static struct file_system_type bfs_fs_type = {
465	.owner		= THIS_MODULE,
466	.name		= "bfs",
467	.get_sb		= bfs_get_sb,
468	.kill_sb	= kill_block_super,
469	.fs_flags	= FS_REQUIRES_DEV,
470};
471
472static int __init init_bfs_fs(void)
473{
474	int err = init_inodecache();
475	if (err)
476		goto out1;
477        err = register_filesystem(&bfs_fs_type);
478	if (err)
479		goto out;
480	return 0;
481out:
482	destroy_inodecache();
483out1:
484	return err;
485}
486
487static void __exit exit_bfs_fs(void)
488{
489	unregister_filesystem(&bfs_fs_type);
490	destroy_inodecache();
491}
492
493module_init(init_bfs_fs)
494module_exit(exit_bfs_fs)
495