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  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 <linux/uio.h>
 19#include <linux/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
 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->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
 86	inode->i_atime.tv_nsec = 0;
 87	inode->i_mtime.tv_nsec = 0;
 88	inode->i_ctime.tv_nsec = 0;
 89
 90	brelse(bh);
 91	unlock_new_inode(inode);
 92	return inode;
 93
 94error:
 95	iget_failed(inode);
 96	return ERR_PTR(-EIO);
 97}
 98
 99static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
100{
101	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
102		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
103		return ERR_PTR(-EIO);
104	}
105
106	ino -= BFS_ROOT_INO;
107
108	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
109	if (!*p) {
110		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
111		return ERR_PTR(-EIO);
112	}
113
114	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
115}
116
117static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
118{
119	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
120	unsigned int ino = (u16)inode->i_ino;
121        unsigned long i_sblock;
122	struct bfs_inode *di;
123	struct buffer_head *bh;
124	int err = 0;
125
126        dprintf("ino=%08x\n", ino);
127
128	di = find_inode(inode->i_sb, ino, &bh);
129	if (IS_ERR(di))
130		return PTR_ERR(di);
131
132	mutex_lock(&info->bfs_lock);
133
134	if (ino == BFS_ROOT_INO)
135		di->i_vtype = cpu_to_le32(BFS_VDIR);
136	else
137		di->i_vtype = cpu_to_le32(BFS_VREG);
138
139	di->i_ino = cpu_to_le16(ino);
140	di->i_mode = cpu_to_le32(inode->i_mode);
141	di->i_uid = cpu_to_le32(i_uid_read(inode));
142	di->i_gid = cpu_to_le32(i_gid_read(inode));
143	di->i_nlink = cpu_to_le32(inode->i_nlink);
144	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
145	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
146	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
147        i_sblock = BFS_I(inode)->i_sblock;
148	di->i_sblock = cpu_to_le32(i_sblock);
149	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
150	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
151
152	mark_buffer_dirty(bh);
153	if (wbc->sync_mode == WB_SYNC_ALL) {
154		sync_dirty_buffer(bh);
155		if (buffer_req(bh) && !buffer_uptodate(bh))
156			err = -EIO;
157	}
158	brelse(bh);
159	mutex_unlock(&info->bfs_lock);
160	return err;
161}
162
163static void bfs_evict_inode(struct inode *inode)
164{
165	unsigned long ino = inode->i_ino;
166	struct bfs_inode *di;
167	struct buffer_head *bh;
168	struct super_block *s = inode->i_sb;
169	struct bfs_sb_info *info = BFS_SB(s);
170	struct bfs_inode_info *bi = BFS_I(inode);
171
172	dprintf("ino=%08lx\n", ino);
173
174	truncate_inode_pages_final(&inode->i_data);
175	invalidate_inode_buffers(inode);
176	clear_inode(inode);
177
178	if (inode->i_nlink)
179		return;
180
181	di = find_inode(s, inode->i_ino, &bh);
182	if (IS_ERR(di))
183		return;
184
185	mutex_lock(&info->bfs_lock);
186	/* clear on-disk inode */
187	memset(di, 0, sizeof(struct bfs_inode));
188	mark_buffer_dirty(bh);
189	brelse(bh);
190
191        if (bi->i_dsk_ino) {
192		if (bi->i_sblock)
193			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
194		info->si_freei++;
195		clear_bit(ino, info->si_imap);
196		bfs_dump_imap("delete_inode", s);
197        }
198
199	/*
200	 * If this was the last file, make the previous block
201	 * "last block of the last file" even if there is no
202	 * real file there, saves us 1 gap.
203	 */
204	if (info->si_lf_eblk == bi->i_eblock)
205		info->si_lf_eblk = bi->i_sblock - 1;
206	mutex_unlock(&info->bfs_lock);
207}
208
209static void bfs_put_super(struct super_block *s)
210{
211	struct bfs_sb_info *info = BFS_SB(s);
212
213	if (!info)
214		return;
215
216	mutex_destroy(&info->bfs_lock);
217	kfree(info->si_imap);
218	kfree(info);
219	s->s_fs_info = NULL;
220}
221
222static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
223{
224	struct super_block *s = dentry->d_sb;
225	struct bfs_sb_info *info = BFS_SB(s);
226	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
227	buf->f_type = BFS_MAGIC;
228	buf->f_bsize = s->s_blocksize;
229	buf->f_blocks = info->si_blocks;
230	buf->f_bfree = buf->f_bavail = info->si_freeb;
231	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
232	buf->f_ffree = info->si_freei;
233	buf->f_fsid.val[0] = (u32)id;
234	buf->f_fsid.val[1] = (u32)(id >> 32);
235	buf->f_namelen = BFS_NAMELEN;
236	return 0;
237}
238
239static struct kmem_cache *bfs_inode_cachep;
240
241static struct inode *bfs_alloc_inode(struct super_block *sb)
242{
243	struct bfs_inode_info *bi;
244	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
245	if (!bi)
246		return NULL;
247	return &bi->vfs_inode;
248}
249
250static void bfs_i_callback(struct rcu_head *head)
251{
252	struct inode *inode = container_of(head, struct inode, i_rcu);
253	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
254}
255
256static void bfs_destroy_inode(struct inode *inode)
257{
258	call_rcu(&inode->i_rcu, bfs_i_callback);
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 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|SLAB_ACCOUNT),
274					     init_once);
275	if (bfs_inode_cachep == NULL)
276		return -ENOMEM;
277	return 0;
278}
279
280static void destroy_inodecache(void)
281{
282	/*
283	 * Make sure all delayed rcu free inodes are flushed before we
284	 * destroy cache.
285	 */
286	rcu_barrier();
287	kmem_cache_destroy(bfs_inode_cachep);
288}
289
290static const struct super_operations bfs_sops = {
291	.alloc_inode	= bfs_alloc_inode,
292	.destroy_inode	= bfs_destroy_inode,
293	.write_inode	= bfs_write_inode,
294	.evict_inode	= bfs_evict_inode,
295	.put_super	= bfs_put_super,
296	.statfs		= bfs_statfs,
297};
298
299void bfs_dump_imap(const char *prefix, struct super_block *s)
300{
301#ifdef DEBUG
302	int i;
303	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
304
305	if (!tmpbuf)
306		return;
307	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
308		if (i > PAGE_SIZE - 100) break;
309		if (test_bit(i, BFS_SB(s)->si_imap))
310			strcat(tmpbuf, "1");
311		else
312			strcat(tmpbuf, "0");
313	}
314	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
315				prefix, BFS_SB(s)->si_lasti, tmpbuf);
316	free_page((unsigned long)tmpbuf);
317#endif
318}
319
320static int bfs_fill_super(struct super_block *s, void *data, int silent)
321{
322	struct buffer_head *bh, *sbh;
323	struct bfs_super_block *bfs_sb;
324	struct inode *inode;
325	unsigned i, imap_len;
326	struct bfs_sb_info *info;
327	int ret = -EINVAL;
328	unsigned long i_sblock, i_eblock, i_eoff, s_size;
329
330	info = kzalloc(sizeof(*info), GFP_KERNEL);
331	if (!info)
332		return -ENOMEM;
333	mutex_init(&info->bfs_lock);
334	s->s_fs_info = info;
335
336	sb_set_blocksize(s, BFS_BSIZE);
337
338	sbh = sb_bread(s, 0);
339	if (!sbh)
340		goto out;
341	bfs_sb = (struct bfs_super_block *)sbh->b_data;
342	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
343		if (!silent)
344			printf("No BFS filesystem on %s (magic=%08x)\n", 
345				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
346		goto out1;
347	}
348	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
349		printf("%s is unclean, continuing\n", s->s_id);
350
351	s->s_magic = BFS_MAGIC;
352
353	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
354		printf("Superblock is corrupted\n");
355		goto out1;
356	}
357
358	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
359					sizeof(struct bfs_inode)
360					+ BFS_ROOT_INO - 1;
361	imap_len = (info->si_lasti / 8) + 1;
362	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
363	if (!info->si_imap)
364		goto out1;
365	for (i = 0; i < BFS_ROOT_INO; i++)
366		set_bit(i, info->si_imap);
367
368	s->s_op = &bfs_sops;
369	inode = bfs_iget(s, BFS_ROOT_INO);
370	if (IS_ERR(inode)) {
371		ret = PTR_ERR(inode);
372		goto out2;
373	}
374	s->s_root = d_make_root(inode);
375	if (!s->s_root) {
376		ret = -ENOMEM;
377		goto out2;
378	}
379
380	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
381	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
382			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
383	info->si_freei = 0;
384	info->si_lf_eblk = 0;
385
386	/* can we read the last block? */
387	bh = sb_bread(s, info->si_blocks - 1);
388	if (!bh) {
389		printf("Last block not available: %lu\n", info->si_blocks - 1);
390		ret = -EIO;
391		goto out3;
392	}
393	brelse(bh);
394
395	bh = NULL;
396	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
397		struct bfs_inode *di;
398		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
399		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
400		unsigned long eblock;
401
402		if (!off) {
403			brelse(bh);
404			bh = sb_bread(s, block);
405		}
406
407		if (!bh)
408			continue;
409
410		di = (struct bfs_inode *)bh->b_data + off;
411
412		/* test if filesystem is not corrupted */
413
414		i_eoff = le32_to_cpu(di->i_eoffset);
415		i_sblock = le32_to_cpu(di->i_sblock);
416		i_eblock = le32_to_cpu(di->i_eblock);
417		s_size = le32_to_cpu(bfs_sb->s_end);
418
419		if (i_sblock > info->si_blocks ||
420			i_eblock > info->si_blocks ||
421			i_sblock > i_eblock ||
422			i_eoff > s_size ||
423			i_sblock * BFS_BSIZE > i_eoff) {
424
425			printf("Inode 0x%08x corrupted\n", i);
426
427			brelse(bh);
428			ret = -EIO;
429			goto out3;
430		}
431
432		if (!di->i_ino) {
433			info->si_freei++;
434			continue;
435		}
436		set_bit(i, info->si_imap);
437		info->si_freeb -= BFS_FILEBLOCKS(di);
438
439		eblock =  le32_to_cpu(di->i_eblock);
440		if (eblock > info->si_lf_eblk)
441			info->si_lf_eblk = eblock;
442	}
443	brelse(bh);
444	brelse(sbh);
445	bfs_dump_imap("read_super", s);
446	return 0;
447
448out3:
449	dput(s->s_root);
450	s->s_root = NULL;
451out2:
452	kfree(info->si_imap);
453out1:
454	brelse(sbh);
455out:
456	mutex_destroy(&info->bfs_lock);
457	kfree(info);
458	s->s_fs_info = NULL;
459	return ret;
460}
461
462static struct dentry *bfs_mount(struct file_system_type *fs_type,
463	int flags, const char *dev_name, void *data)
464{
465	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
466}
467
468static struct file_system_type bfs_fs_type = {
469	.owner		= THIS_MODULE,
470	.name		= "bfs",
471	.mount		= bfs_mount,
472	.kill_sb	= kill_block_super,
473	.fs_flags	= FS_REQUIRES_DEV,
474};
475MODULE_ALIAS_FS("bfs");
476
477static int __init init_bfs_fs(void)
478{
479	int err = init_inodecache();
480	if (err)
481		goto out1;
482        err = register_filesystem(&bfs_fs_type);
483	if (err)
484		goto out;
485	return 0;
486out:
487	destroy_inodecache();
488out1:
489	return err;
490}
491
492static void __exit exit_bfs_fs(void)
493{
494	unregister_filesystem(&bfs_fs_type);
495	destroy_inodecache();
496}
497
498module_init(init_bfs_fs)
499module_exit(exit_bfs_fs)
  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->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
 86	inode->i_atime.tv_nsec = 0;
 87	inode->i_mtime.tv_nsec = 0;
 88	inode->i_ctime.tv_nsec = 0;
 89
 90	brelse(bh);
 91	unlock_new_inode(inode);
 92	return inode;
 93
 94error:
 95	iget_failed(inode);
 96	return ERR_PTR(-EIO);
 97}
 98
 99static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
100{
101	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
102		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
103		return ERR_PTR(-EIO);
104	}
105
106	ino -= BFS_ROOT_INO;
107
108	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
109	if (!*p) {
110		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
111		return ERR_PTR(-EIO);
112	}
113
114	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
115}
116
117static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
118{
119	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
120	unsigned int ino = (u16)inode->i_ino;
121	unsigned long i_sblock;
122	struct bfs_inode *di;
123	struct buffer_head *bh;
124	int err = 0;
125
126	dprintf("ino=%08x\n", ino);
127
128	di = find_inode(inode->i_sb, ino, &bh);
129	if (IS_ERR(di))
130		return PTR_ERR(di);
131
132	mutex_lock(&info->bfs_lock);
133
134	if (ino == BFS_ROOT_INO)
135		di->i_vtype = cpu_to_le32(BFS_VDIR);
136	else
137		di->i_vtype = cpu_to_le32(BFS_VREG);
138
139	di->i_ino = cpu_to_le16(ino);
140	di->i_mode = cpu_to_le32(inode->i_mode);
141	di->i_uid = cpu_to_le32(i_uid_read(inode));
142	di->i_gid = cpu_to_le32(i_gid_read(inode));
143	di->i_nlink = cpu_to_le32(inode->i_nlink);
144	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
145	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
146	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
147	i_sblock = BFS_I(inode)->i_sblock;
148	di->i_sblock = cpu_to_le32(i_sblock);
149	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
150	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
151
152	mark_buffer_dirty(bh);
153	if (wbc->sync_mode == WB_SYNC_ALL) {
154		sync_dirty_buffer(bh);
155		if (buffer_req(bh) && !buffer_uptodate(bh))
156			err = -EIO;
157	}
158	brelse(bh);
159	mutex_unlock(&info->bfs_lock);
160	return err;
161}
162
163static void bfs_evict_inode(struct inode *inode)
164{
165	unsigned long ino = inode->i_ino;
166	struct bfs_inode *di;
167	struct buffer_head *bh;
168	struct super_block *s = inode->i_sb;
169	struct bfs_sb_info *info = BFS_SB(s);
170	struct bfs_inode_info *bi = BFS_I(inode);
171
172	dprintf("ino=%08lx\n", ino);
173
174	truncate_inode_pages_final(&inode->i_data);
175	invalidate_inode_buffers(inode);
176	clear_inode(inode);
177
178	if (inode->i_nlink)
179		return;
180
181	di = find_inode(s, inode->i_ino, &bh);
182	if (IS_ERR(di))
183		return;
184
185	mutex_lock(&info->bfs_lock);
186	/* clear on-disk inode */
187	memset(di, 0, sizeof(struct bfs_inode));
188	mark_buffer_dirty(bh);
189	brelse(bh);
190
191	if (bi->i_dsk_ino) {
192		if (bi->i_sblock)
193			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
194		info->si_freei++;
195		clear_bit(ino, info->si_imap);
196		bfs_dump_imap("evict_inode", s);
197	}
198
199	/*
200	 * If this was the last file, make the previous block
201	 * "last block of the last file" even if there is no
202	 * real file there, saves us 1 gap.
203	 */
204	if (info->si_lf_eblk == bi->i_eblock)
205		info->si_lf_eblk = bi->i_sblock - 1;
206	mutex_unlock(&info->bfs_lock);
207}
208
209static void bfs_put_super(struct super_block *s)
210{
211	struct bfs_sb_info *info = BFS_SB(s);
212
213	if (!info)
214		return;
215
216	mutex_destroy(&info->bfs_lock);
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_free_inode(struct inode *inode)
250{
251	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
252}
253
254static void init_once(void *foo)
255{
256	struct bfs_inode_info *bi = foo;
257
258	inode_init_once(&bi->vfs_inode);
259}
260
261static int __init init_inodecache(void)
262{
263	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
264					     sizeof(struct bfs_inode_info),
265					     0, (SLAB_RECLAIM_ACCOUNT|
266						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
267					     init_once);
268	if (bfs_inode_cachep == NULL)
269		return -ENOMEM;
270	return 0;
271}
272
273static void destroy_inodecache(void)
274{
275	/*
276	 * Make sure all delayed rcu free inodes are flushed before we
277	 * destroy cache.
278	 */
279	rcu_barrier();
280	kmem_cache_destroy(bfs_inode_cachep);
281}
282
283static const struct super_operations bfs_sops = {
284	.alloc_inode	= bfs_alloc_inode,
285	.free_inode	= bfs_free_inode,
286	.write_inode	= bfs_write_inode,
287	.evict_inode	= bfs_evict_inode,
288	.put_super	= bfs_put_super,
289	.statfs		= bfs_statfs,
290};
291
292void bfs_dump_imap(const char *prefix, struct super_block *s)
293{
294#ifdef DEBUG
295	int i;
296	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
297
298	if (!tmpbuf)
299		return;
300	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
301		if (i > PAGE_SIZE - 100) break;
302		if (test_bit(i, BFS_SB(s)->si_imap))
303			strcat(tmpbuf, "1");
304		else
305			strcat(tmpbuf, "0");
306	}
307	printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
308	free_page((unsigned long)tmpbuf);
309#endif
310}
311
312static int bfs_fill_super(struct super_block *s, void *data, int silent)
313{
314	struct buffer_head *bh, *sbh;
315	struct bfs_super_block *bfs_sb;
316	struct inode *inode;
317	unsigned i;
318	struct bfs_sb_info *info;
319	int ret = -EINVAL;
320	unsigned long i_sblock, i_eblock, i_eoff, s_size;
321
322	info = kzalloc(sizeof(*info), GFP_KERNEL);
323	if (!info)
324		return -ENOMEM;
325	mutex_init(&info->bfs_lock);
326	s->s_fs_info = info;
327	s->s_time_min = 0;
328	s->s_time_max = U32_MAX;
329
330	sb_set_blocksize(s, BFS_BSIZE);
331
332	sbh = sb_bread(s, 0);
333	if (!sbh)
334		goto out;
335	bfs_sb = (struct bfs_super_block *)sbh->b_data;
336	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
337		if (!silent)
338			printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
339		goto out1;
340	}
341	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
342		printf("%s is unclean, continuing\n", s->s_id);
343
344	s->s_magic = BFS_MAGIC;
345
346	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
347	    le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
348		printf("Superblock is corrupted on %s\n", s->s_id);
349		goto out1;
350	}
351
352	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
353	if (info->si_lasti == BFS_MAX_LASTI)
354		printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
355	else if (info->si_lasti > BFS_MAX_LASTI) {
356		printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
357		goto out1;
358	}
359	for (i = 0; i < BFS_ROOT_INO; i++)
360		set_bit(i, info->si_imap);
361
362	s->s_op = &bfs_sops;
363	inode = bfs_iget(s, BFS_ROOT_INO);
364	if (IS_ERR(inode)) {
365		ret = PTR_ERR(inode);
366		goto out1;
367	}
368	s->s_root = d_make_root(inode);
369	if (!s->s_root) {
370		ret = -ENOMEM;
371		goto out1;
372	}
373
374	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
375	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
376	info->si_freei = 0;
377	info->si_lf_eblk = 0;
378
379	/* can we read the last block? */
380	bh = sb_bread(s, info->si_blocks - 1);
381	if (!bh) {
382		printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
383		ret = -EIO;
384		goto out2;
385	}
386	brelse(bh);
387
388	bh = NULL;
389	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
390		struct bfs_inode *di;
391		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
392		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
393		unsigned long eblock;
394
395		if (!off) {
396			brelse(bh);
397			bh = sb_bread(s, block);
398		}
399
400		if (!bh)
401			continue;
402
403		di = (struct bfs_inode *)bh->b_data + off;
404
405		/* test if filesystem is not corrupted */
406
407		i_eoff = le32_to_cpu(di->i_eoffset);
408		i_sblock = le32_to_cpu(di->i_sblock);
409		i_eblock = le32_to_cpu(di->i_eblock);
410		s_size = le32_to_cpu(bfs_sb->s_end);
411
412		if (i_sblock > info->si_blocks ||
413			i_eblock > info->si_blocks ||
414			i_sblock > i_eblock ||
415			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
416			i_sblock * BFS_BSIZE > i_eoff) {
417
418			printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
419
420			brelse(bh);
421			ret = -EIO;
422			goto out2;
423		}
424
425		if (!di->i_ino) {
426			info->si_freei++;
427			continue;
428		}
429		set_bit(i, info->si_imap);
430		info->si_freeb -= BFS_FILEBLOCKS(di);
431
432		eblock =  le32_to_cpu(di->i_eblock);
433		if (eblock > info->si_lf_eblk)
434			info->si_lf_eblk = eblock;
435	}
436	brelse(bh);
437	brelse(sbh);
438	bfs_dump_imap("fill_super", s);
439	return 0;
440
441out2:
442	dput(s->s_root);
443	s->s_root = NULL;
444out1:
445	brelse(sbh);
446out:
447	mutex_destroy(&info->bfs_lock);
448	kfree(info);
449	s->s_fs_info = NULL;
450	return ret;
451}
452
453static struct dentry *bfs_mount(struct file_system_type *fs_type,
454	int flags, const char *dev_name, void *data)
455{
456	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
457}
458
459static struct file_system_type bfs_fs_type = {
460	.owner		= THIS_MODULE,
461	.name		= "bfs",
462	.mount		= bfs_mount,
463	.kill_sb	= kill_block_super,
464	.fs_flags	= FS_REQUIRES_DEV,
465};
466MODULE_ALIAS_FS("bfs");
467
468static int __init init_bfs_fs(void)
469{
470	int err = init_inodecache();
471	if (err)
472		goto out1;
473	err = register_filesystem(&bfs_fs_type);
474	if (err)
475		goto out;
476	return 0;
477out:
478	destroy_inodecache();
479out1:
480	return err;
481}
482
483static void __exit exit_bfs_fs(void)
484{
485	unregister_filesystem(&bfs_fs_type);
486	destroy_inodecache();
487}
488
489module_init(init_bfs_fs)
490module_exit(exit_bfs_fs)