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v6.13.7
  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)
v5.14.15
  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 = u64_to_fsid(id);
233	buf->f_namelen = BFS_NAMELEN;
234	return 0;
235}
236
237static struct kmem_cache *bfs_inode_cachep;
238
239static struct inode *bfs_alloc_inode(struct super_block *sb)
240{
241	struct bfs_inode_info *bi;
242	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
243	if (!bi)
244		return NULL;
245	return &bi->vfs_inode;
246}
247
248static void bfs_free_inode(struct inode *inode)
249{
250	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
251}
252
253static void init_once(void *foo)
254{
255	struct bfs_inode_info *bi = foo;
256
257	inode_init_once(&bi->vfs_inode);
258}
259
260static int __init init_inodecache(void)
261{
262	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
263					     sizeof(struct bfs_inode_info),
264					     0, (SLAB_RECLAIM_ACCOUNT|
265						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
266					     init_once);
267	if (bfs_inode_cachep == NULL)
268		return -ENOMEM;
269	return 0;
270}
271
272static void destroy_inodecache(void)
273{
274	/*
275	 * Make sure all delayed rcu free inodes are flushed before we
276	 * destroy cache.
277	 */
278	rcu_barrier();
279	kmem_cache_destroy(bfs_inode_cachep);
280}
281
282static const struct super_operations bfs_sops = {
283	.alloc_inode	= bfs_alloc_inode,
284	.free_inode	= bfs_free_inode,
285	.write_inode	= bfs_write_inode,
286	.evict_inode	= bfs_evict_inode,
287	.put_super	= bfs_put_super,
288	.statfs		= bfs_statfs,
289};
290
291void bfs_dump_imap(const char *prefix, struct super_block *s)
292{
293#ifdef DEBUG
294	int i;
295	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
296
297	if (!tmpbuf)
298		return;
299	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
300		if (i > PAGE_SIZE - 100) break;
301		if (test_bit(i, BFS_SB(s)->si_imap))
302			strcat(tmpbuf, "1");
303		else
304			strcat(tmpbuf, "0");
305	}
306	printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
307	free_page((unsigned long)tmpbuf);
308#endif
309}
310
311static int bfs_fill_super(struct super_block *s, void *data, int silent)
312{
313	struct buffer_head *bh, *sbh;
314	struct bfs_super_block *bfs_sb;
315	struct inode *inode;
316	unsigned i;
317	struct bfs_sb_info *info;
318	int ret = -EINVAL;
319	unsigned long i_sblock, i_eblock, i_eoff, s_size;
320
321	info = kzalloc(sizeof(*info), GFP_KERNEL);
322	if (!info)
323		return -ENOMEM;
324	mutex_init(&info->bfs_lock);
325	s->s_fs_info = info;
326	s->s_time_min = 0;
327	s->s_time_max = U32_MAX;
328
329	sb_set_blocksize(s, BFS_BSIZE);
330
331	sbh = sb_bread(s, 0);
332	if (!sbh)
333		goto out;
334	bfs_sb = (struct bfs_super_block *)sbh->b_data;
335	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
336		if (!silent)
337			printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
338		goto out1;
339	}
340	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
341		printf("%s is unclean, continuing\n", s->s_id);
342
343	s->s_magic = BFS_MAGIC;
344
345	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
346	    le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
347		printf("Superblock is corrupted on %s\n", s->s_id);
348		goto out1;
349	}
350
351	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
352	if (info->si_lasti == BFS_MAX_LASTI)
353		printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
354	else if (info->si_lasti > BFS_MAX_LASTI) {
355		printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
356		goto out1;
357	}
358	for (i = 0; i < BFS_ROOT_INO; i++)
359		set_bit(i, info->si_imap);
360
361	s->s_op = &bfs_sops;
362	inode = bfs_iget(s, BFS_ROOT_INO);
363	if (IS_ERR(inode)) {
364		ret = PTR_ERR(inode);
365		goto out1;
366	}
367	s->s_root = d_make_root(inode);
368	if (!s->s_root) {
369		ret = -ENOMEM;
370		goto out1;
371	}
372
373	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
374	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
375	info->si_freei = 0;
376	info->si_lf_eblk = 0;
377
378	/* can we read the last block? */
379	bh = sb_bread(s, info->si_blocks - 1);
380	if (!bh) {
381		printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
382		ret = -EIO;
383		goto out2;
384	}
385	brelse(bh);
386
387	bh = NULL;
388	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
389		struct bfs_inode *di;
390		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
391		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
392		unsigned long eblock;
393
394		if (!off) {
395			brelse(bh);
396			bh = sb_bread(s, block);
397		}
398
399		if (!bh)
400			continue;
401
402		di = (struct bfs_inode *)bh->b_data + off;
403
404		/* test if filesystem is not corrupted */
405
406		i_eoff = le32_to_cpu(di->i_eoffset);
407		i_sblock = le32_to_cpu(di->i_sblock);
408		i_eblock = le32_to_cpu(di->i_eblock);
409		s_size = le32_to_cpu(bfs_sb->s_end);
410
411		if (i_sblock > info->si_blocks ||
412			i_eblock > info->si_blocks ||
413			i_sblock > i_eblock ||
414			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
415			i_sblock * BFS_BSIZE > i_eoff) {
416
417			printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
418
419			brelse(bh);
420			ret = -EIO;
421			goto out2;
422		}
423
424		if (!di->i_ino) {
425			info->si_freei++;
426			continue;
427		}
428		set_bit(i, info->si_imap);
429		info->si_freeb -= BFS_FILEBLOCKS(di);
430
431		eblock =  le32_to_cpu(di->i_eblock);
432		if (eblock > info->si_lf_eblk)
433			info->si_lf_eblk = eblock;
434	}
435	brelse(bh);
436	brelse(sbh);
437	bfs_dump_imap("fill_super", s);
438	return 0;
439
440out2:
441	dput(s->s_root);
442	s->s_root = NULL;
443out1:
444	brelse(sbh);
445out:
446	mutex_destroy(&info->bfs_lock);
447	kfree(info);
448	s->s_fs_info = NULL;
449	return ret;
450}
451
452static struct dentry *bfs_mount(struct file_system_type *fs_type,
453	int flags, const char *dev_name, void *data)
454{
455	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
456}
457
458static struct file_system_type bfs_fs_type = {
459	.owner		= THIS_MODULE,
460	.name		= "bfs",
461	.mount		= bfs_mount,
462	.kill_sb	= kill_block_super,
463	.fs_flags	= FS_REQUIRES_DEV,
464};
465MODULE_ALIAS_FS("bfs");
466
467static int __init init_bfs_fs(void)
468{
469	int err = init_inodecache();
470	if (err)
471		goto out1;
472	err = register_filesystem(&bfs_fs_type);
473	if (err)
474		goto out;
475	return 0;
476out:
477	destroy_inodecache();
478out1:
479	return err;
480}
481
482static void __exit exit_bfs_fs(void)
483{
484	unregister_filesystem(&bfs_fs_type);
485	destroy_inodecache();
486}
487
488module_init(init_bfs_fs)
489module_exit(exit_bfs_fs)