[linux.git] / fs / sysv / dir.c

/*
 *  linux/fs/sysv/dir.c
 *
 *  minix/dir.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  coh/dir.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/dir.c
 *  Copyright (C) 1993  Bruno Haible
 *
 *  SystemV/Coherent directory handling functions
 */

#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include "sysv.h"

static int sysv_readdir(struct file *, struct dir_context *);

const struct file_operations sysv_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate	= sysv_readdir,
	.fsync		= generic_file_fsync,
};

static inline void dir_put_page(struct page *page)
{
	kunmap(page);
	page_cache_release(page);
}

static inline unsigned long dir_pages(struct inode *inode)
{
	return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
}

static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
{
	struct address_space *mapping = page->mapping;
	struct inode *dir = mapping->host;
	int err = 0;

	block_write_end(NULL, mapping, pos, len, len, page, NULL);
	if (pos+len > dir->i_size) {
		i_size_write(dir, pos+len);
		mark_inode_dirty(dir);
	}
	if (IS_DIRSYNC(dir))
		err = write_one_page(page, 1);
	else
		unlock_page(page);
	return err;
}

static struct page * dir_get_page(struct inode *dir, unsigned long n)
{
	struct address_space *mapping = dir->i_mapping;
	struct page *page = read_mapping_page(mapping, n, NULL);
	if (!IS_ERR(page))
		kmap(page);
	return page;
}

static int sysv_readdir(struct file *file, struct dir_context *ctx)
{
	unsigned long pos = ctx->pos;
	struct inode *inode = file_inode(file);
	struct super_block *sb = inode->i_sb;
	unsigned long npages = dir_pages(inode);
	unsigned offset;
	unsigned long n;

	ctx->pos = pos = (pos + SYSV_DIRSIZE-1) & ~(SYSV_DIRSIZE-1);
	if (pos >= inode->i_size)
		return 0;

	offset = pos & ~PAGE_CACHE_MASK;
	n = pos >> PAGE_CACHE_SHIFT;

	for ( ; n < npages; n++, offset = 0) {
		char *kaddr, *limit;
		struct sysv_dir_entry *de;
		struct page *page = dir_get_page(inode, n);

		if (IS_ERR(page))
			continue;
		kaddr = (char *)page_address(page);
		de = (struct sysv_dir_entry *)(kaddr+offset);
		limit = kaddr + PAGE_CACHE_SIZE - SYSV_DIRSIZE;
		for ( ;(char*)de <= limit; de++, ctx->pos += sizeof(*de)) {
			char *name = de->name;

			if (!de->inode)
				continue;

			if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
					fs16_to_cpu(SYSV_SB(sb), de->inode),
					DT_UNKNOWN)) {
				dir_put_page(page);
				return 0;
			}
		}
		dir_put_page(page);
	}
	return 0;
}

/* compare strings: name[0..len-1] (not zero-terminated) and
 * buffer[0..] (filled with zeroes up to buffer[0..maxlen-1])
 */
static inline int namecompare(int len, int maxlen,
	const char * name, const char * buffer)
{
	if (len < maxlen && buffer[len])
		return 0;
	return !memcmp(name, buffer, len);
}

/*
 *	sysv_find_entry()
 *
 * finds an entry in the specified directory with the wanted name. It
 * returns the cache buffer in which the entry was found, and the entry
 * itself (as a parameter - res_dir). It does NOT read the inode of the
 * entry - you'll have to do that yourself if you want to.
 */
struct sysv_dir_entry *sysv_find_entry(struct dentry *dentry, struct page **res_page)
{
	const char * name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct inode * dir = dentry->d_parent->d_inode;
	unsigned long start, n;
	unsigned long npages = dir_pages(dir);
	struct page *page = NULL;
	struct sysv_dir_entry *de;

	*res_page = NULL;

	start = SYSV_I(dir)->i_dir_start_lookup;
	if (start >= npages)
		start = 0;
	n = start;

	do {
		char *kaddr;
		page = dir_get_page(dir, n);
		if (!IS_ERR(page)) {
			kaddr = (char*)page_address(page);
			de = (struct sysv_dir_entry *) kaddr;
			kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
			for ( ; (char *) de <= kaddr ; de++) {
				if (!de->inode)
					continue;
				if (namecompare(namelen, SYSV_NAMELEN,
							name, de->name))
					goto found;
			}
			dir_put_page(page);
		}

		if (++n >= npages)
			n = 0;
	} while (n != start);

	return NULL;

found:
	SYSV_I(dir)->i_dir_start_lookup = n;
	*res_page = page;
	return de;
}

int sysv_add_link(struct dentry *dentry, struct inode *inode)
{
	struct inode *dir = dentry->d_parent->d_inode;
	const char * name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct page *page = NULL;
	struct sysv_dir_entry * de;
	unsigned long npages = dir_pages(dir);
	unsigned long n;
	char *kaddr;
	loff_t pos;
	int err;

	/* We take care of directory expansion in the same loop */
	for (n = 0; n <= npages; n++) {
		page = dir_get_page(dir, n);
		err = PTR_ERR(page);
		if (IS_ERR(page))
			goto out;
		kaddr = (char*)page_address(page);
		de = (struct sysv_dir_entry *)kaddr;
		kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
		while ((char *)de <= kaddr) {
			if (!de->inode)
				goto got_it;
			err = -EEXIST;
			if (namecompare(namelen, SYSV_NAMELEN, name, de->name)) 
				goto out_page;
			de++;
		}
		dir_put_page(page);
	}
	BUG();
	return -EINVAL;

got_it:
	pos = page_offset(page) +
			(char*)de - (char*)page_address(page);
	lock_page(page);
	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
	if (err)
		goto out_unlock;
	memcpy (de->name, name, namelen);
	memset (de->name + namelen, 0, SYSV_DIRSIZE - namelen - 2);
	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(dir);
out_page:
	dir_put_page(page);
out:
	return err;
out_unlock:
	unlock_page(page);
	goto out_page;
}

int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
{
	struct inode *inode = page->mapping->host;
	char *kaddr = (char*)page_address(page);
	loff_t pos = page_offset(page) + (char *)de - kaddr;
	int err;

	lock_page(page);
	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
	BUG_ON(err);
	de->inode = 0;
	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
	dir_put_page(page);
	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	return err;
}

int sysv_make_empty(struct inode *inode, struct inode *dir)
{
	struct page *page = grab_cache_page(inode->i_mapping, 0);
	struct sysv_dir_entry * de;
	char *base;
	int err;

	if (!page)
		return -ENOMEM;
	err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
	if (err) {
		unlock_page(page);
		goto fail;
	}
	kmap(page);

	base = (char*)page_address(page);
	memset(base, 0, PAGE_CACHE_SIZE);

	de = (struct sysv_dir_entry *) base;
	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	strcpy(de->name,".");
	de++;
	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
	strcpy(de->name,"..");

	kunmap(page);
	err = dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
fail:
	page_cache_release(page);
	return err;
}

/*
 * routine to check that the specified directory is empty (for rmdir)
 */
int sysv_empty_dir(struct inode * inode)
{
	struct super_block *sb = inode->i_sb;
	struct page *page = NULL;
	unsigned long i, npages = dir_pages(inode);

	for (i = 0; i < npages; i++) {
		char *kaddr;
		struct sysv_dir_entry * de;
		page = dir_get_page(inode, i);

		if (IS_ERR(page))
			continue;

		kaddr = (char *)page_address(page);
		de = (struct sysv_dir_entry *)kaddr;
		kaddr += PAGE_CACHE_SIZE-SYSV_DIRSIZE;

		for ( ;(char *)de <= kaddr; de++) {
			if (!de->inode)
				continue;
			/* check for . and .. */
			if (de->name[0] != '.')
				goto not_empty;
			if (!de->name[1]) {
				if (de->inode == cpu_to_fs16(SYSV_SB(sb),
							inode->i_ino))
					continue;
				goto not_empty;
			}
			if (de->name[1] != '.' || de->name[2])
				goto not_empty;
		}
		dir_put_page(page);
	}
	return 1;

not_empty:
	dir_put_page(page);
	return 0;
}

/* Releases the page */
void sysv_set_link(struct sysv_dir_entry *de, struct page *page,
	struct inode *inode)
{
	struct inode *dir = page->mapping->host;
	loff_t pos = page_offset(page) +
			(char *)de-(char*)page_address(page);
	int err;

	lock_page(page);
	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
	BUG_ON(err);
	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
	dir_put_page(page);
	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(dir);
}

struct sysv_dir_entry * sysv_dotdot (struct inode *dir, struct page **p)
{
	struct page *page = dir_get_page(dir, 0);
	struct sysv_dir_entry *de = NULL;

	if (!IS_ERR(page)) {
		de = (struct sysv_dir_entry*) page_address(page) + 1;
		*p = page;
	}
	return de;
}

ino_t sysv_inode_by_name(struct dentry *dentry)
{
	struct page *page;
	struct sysv_dir_entry *de = sysv_find_entry (dentry, &page);
	ino_t res = 0;
	
	if (de) {
		res = fs16_to_cpu(SYSV_SB(dentry->d_sb), de->inode);
		dir_put_page(page);
	}
	return res;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/sysv/dir.c
	3	*
	4	* minix/dir.c
	5	* Copyright (C) 1991, 1992 Linus Torvalds
	6	*
	7	* coh/dir.c
	8	* Copyright (C) 1993 Pascal Haible, Bruno Haible
	9	*
	10	* sysv/dir.c
	11	* Copyright (C) 1993 Bruno Haible
	12	*
	13	* SystemV/Coherent directory handling functions
	14	*/
	15
	16	#include <linux/pagemap.h>
	17	#include <linux/highmem.h>
26a6441a	18	#include <linux/swap.h>
1da177e4 LT	19	#include "sysv.h"
1da177e4 LT	20
80886298	21	static int sysv_readdir(struct file , struct dir_context );
1da177e4	22
4b6f5d20	23	const struct file_operations sysv_dir_operations = {
5ac3455a	24	.llseek = generic_file_llseek,
1da177e4	25	.read = generic_read_dir,
80886298	26	.iterate = sysv_readdir,
1b061d92	27	.fsync = generic_file_fsync,
1da177e4 LT	28	};
	29
	30	static inline void dir_put_page(struct page *page)
	31	{
	32	kunmap(page);
	33	page_cache_release(page);
	34	}
	35
	36	static inline unsigned long dir_pages(struct inode *inode)
	37	{
	38	return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
	39	}
	40
26a6441a	41	static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
1da177e4	42	{
26a6441a NP	43	struct address_space *mapping = page->mapping;
26a6441a NP	44	struct inode *dir = mapping->host;
1da177e4 LT	45	int err = 0;
1da177e4 LT	46
26a6441a NP	47	block_write_end(NULL, mapping, pos, len, len, page, NULL);
	48	if (pos+len > dir->i_size) {
	49	i_size_write(dir, pos+len);
	50	mark_inode_dirty(dir);
	51	}
1da177e4 LT	52	if (IS_DIRSYNC(dir))
	53	err = write_one_page(page, 1);
	54	else
	55	unlock_page(page);
	56	return err;
	57	}
	58
	59	static struct page * dir_get_page(struct inode *dir, unsigned long n)
	60	{
	61	struct address_space *mapping = dir->i_mapping;
090d2b18	62	struct page *page = read_mapping_page(mapping, n, NULL);
6fe6900e	63	if (!IS_ERR(page))
1da177e4	64	kmap(page);
1da177e4	65	return page;
1da177e4 LT	66	}
1da177e4 LT	67
80886298	68	static int sysv_readdir(struct file file, struct dir_context ctx)
1da177e4	69	{
80886298 AV	70	unsigned long pos = ctx->pos;
80886298 AV	71	struct inode *inode = file_inode(file);
1da177e4	72	struct super_block *sb = inode->i_sb;
1da177e4	73	unsigned long npages = dir_pages(inode);
80886298 AV	74	unsigned offset;
80886298 AV	75	unsigned long n;
1da177e4	76
80886298	77	ctx->pos = pos = (pos + SYSV_DIRSIZE-1) & ~(SYSV_DIRSIZE-1);
1da177e4	78	if (pos >= inode->i_size)
80886298 AV	79	return 0;
	80
	81	offset = pos & ~PAGE_CACHE_MASK;
	82	n = pos >> PAGE_CACHE_SHIFT;
1da177e4 LT	83
	84	for ( ; n < npages; n++, offset = 0) {
	85	char kaddr, limit;
	86	struct sysv_dir_entry *de;
	87	struct page *page = dir_get_page(inode, n);
	88
	89	if (IS_ERR(page))
	90	continue;
	91	kaddr = (char *)page_address(page);
	92	de = (struct sysv_dir_entry *)(kaddr+offset);
	93	limit = kaddr + PAGE_CACHE_SIZE - SYSV_DIRSIZE;
80886298	94	for ( ;(char)de <= limit; de++, ctx->pos += sizeof(de)) {
1da177e4	95	char *name = de->name;
1da177e4 LT	96
	97	if (!de->inode)
	98	continue;
	99
80886298	100	if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
1da177e4	101	fs16_to_cpu(SYSV_SB(sb), de->inode),
80886298	102	DT_UNKNOWN)) {
1da177e4	103	dir_put_page(page);
80886298	104	return 0;
1da177e4 LT	105	}
	106	}
	107	dir_put_page(page);
	108	}
1da177e4 LT	109	return 0;
	110	}
	111
	112	/* compare strings: name[0..len-1] (not zero-terminated) and
	113	* buffer[0..] (filled with zeroes up to buffer[0..maxlen-1])
	114	*/
	115	static inline int namecompare(int len, int maxlen,
	116	const char * name, const char * buffer)
	117	{
	118	if (len < maxlen && buffer[len])
	119	return 0;
	120	return !memcmp(name, buffer, len);
	121	}
	122
	123	/*
	124	* sysv_find_entry()
	125	*
	126	* finds an entry in the specified directory with the wanted name. It
	127	* returns the cache buffer in which the entry was found, and the entry
	128	* itself (as a parameter - res_dir). It does NOT read the inode of the
	129	* entry - you'll have to do that yourself if you want to.
	130	*/
	131	struct sysv_dir_entry sysv_find_entry(struct dentry dentry, struct page **res_page)
	132	{
	133	const char * name = dentry->d_name.name;
	134	int namelen = dentry->d_name.len;
	135	struct inode * dir = dentry->d_parent->d_inode;
	136	unsigned long start, n;
	137	unsigned long npages = dir_pages(dir);
	138	struct page *page = NULL;
	139	struct sysv_dir_entry *de;
	140
	141	*res_page = NULL;
	142
	143	start = SYSV_I(dir)->i_dir_start_lookup;
	144	if (start >= npages)
	145	start = 0;
	146	n = start;
	147
	148	do {
	149	char *kaddr;
	150	page = dir_get_page(dir, n);
	151	if (!IS_ERR(page)) {
	152	kaddr = (char*)page_address(page);
	153	de = (struct sysv_dir_entry *) kaddr;
	154	kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
	155	for ( ; (char *) de <= kaddr ; de++) {
	156	if (!de->inode)
	157	continue;
	158	if (namecompare(namelen, SYSV_NAMELEN,
	159	name, de->name))
	160	goto found;
	161	}
404e7812	162	dir_put_page(page);
1da177e4	163	}
1da177e4 LT	164
	165	if (++n >= npages)
	166	n = 0;
	167	} while (n != start);
	168
	169	return NULL;
	170
	171	found:
	172	SYSV_I(dir)->i_dir_start_lookup = n;
	173	*res_page = page;
	174	return de;
	175	}
	176
	177	int sysv_add_link(struct dentry dentry, struct inode inode)
	178	{
	179	struct inode *dir = dentry->d_parent->d_inode;
	180	const char * name = dentry->d_name.name;
	181	int namelen = dentry->d_name.len;
	182	struct page *page = NULL;
	183	struct sysv_dir_entry * de;
	184	unsigned long npages = dir_pages(dir);
	185	unsigned long n;
	186	char *kaddr;
26a6441a	187	loff_t pos;
1da177e4 LT	188	int err;
	189
	190	/* We take care of directory expansion in the same loop */
	191	for (n = 0; n <= npages; n++) {
	192	page = dir_get_page(dir, n);
	193	err = PTR_ERR(page);
	194	if (IS_ERR(page))
	195	goto out;
	196	kaddr = (char*)page_address(page);
	197	de = (struct sysv_dir_entry *)kaddr;
	198	kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
	199	while ((char *)de <= kaddr) {
	200	if (!de->inode)
	201	goto got_it;
	202	err = -EEXIST;
	203	if (namecompare(namelen, SYSV_NAMELEN, name, de->name))
	204	goto out_page;
	205	de++;
	206	}
	207	dir_put_page(page);
	208	}
	209	BUG();
	210	return -EINVAL;
	211
	212	got_it:
26a6441a NP	213	pos = page_offset(page) +
26a6441a NP	214	(char)de - (char)page_address(page);
1da177e4	215	lock_page(page);
f4e420dc	216	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	217	if (err)
	218	goto out_unlock;
	219	memcpy (de->name, name, namelen);
	220	memset (de->name + namelen, 0, SYSV_DIRSIZE - namelen - 2);
	221	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
26a6441a	222	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	223	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
	224	mark_inode_dirty(dir);
	225	out_page:
	226	dir_put_page(page);
	227	out:
	228	return err;
	229	out_unlock:
	230	unlock_page(page);
	231	goto out_page;
	232	}
	233
	234	int sysv_delete_entry(struct sysv_dir_entry de, struct page page)
	235	{
f4e420dc	236	struct inode *inode = page->mapping->host;
1da177e4	237	char kaddr = (char)page_address(page);
26a6441a	238	loff_t pos = page_offset(page) + (char *)de - kaddr;
1da177e4 LT	239	int err;
	240
	241	lock_page(page);
f4e420dc	242	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	243	BUG_ON(err);
1da177e4	244	de->inode = 0;
26a6441a	245	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	246	dir_put_page(page);
	247	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	248	mark_inode_dirty(inode);
	249	return err;
	250	}
	251
	252	int sysv_make_empty(struct inode inode, struct inode dir)
	253	{
f4e420dc	254	struct page *page = grab_cache_page(inode->i_mapping, 0);
1da177e4 LT	255	struct sysv_dir_entry * de;
	256	char *base;
	257	int err;
	258
	259	if (!page)
	260	return -ENOMEM;
f4e420dc	261	err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
1da177e4 LT	262	if (err) {
	263	unlock_page(page);
	264	goto fail;
	265	}
26a6441a	266	kmap(page);
1da177e4 LT	267
	268	base = (char*)page_address(page);
	269	memset(base, 0, PAGE_CACHE_SIZE);
	270
	271	de = (struct sysv_dir_entry *) base;
	272	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	273	strcpy(de->name,".");
	274	de++;
	275	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
	276	strcpy(de->name,"..");
	277
26a6441a	278	kunmap(page);
1da177e4 LT	279	err = dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
1da177e4 LT	280	fail:
1da177e4 LT	281	page_cache_release(page);
	282	return err;
	283	}
	284
	285	/*
	286	* routine to check that the specified directory is empty (for rmdir)
	287	*/
	288	int sysv_empty_dir(struct inode * inode)
	289	{
	290	struct super_block *sb = inode->i_sb;
	291	struct page *page = NULL;
	292	unsigned long i, npages = dir_pages(inode);
	293
	294	for (i = 0; i < npages; i++) {
	295	char *kaddr;
	296	struct sysv_dir_entry * de;
	297	page = dir_get_page(inode, i);
	298
	299	if (IS_ERR(page))
	300	continue;
	301
	302	kaddr = (char *)page_address(page);
	303	de = (struct sysv_dir_entry *)kaddr;
	304	kaddr += PAGE_CACHE_SIZE-SYSV_DIRSIZE;
	305
	306	for ( ;(char *)de <= kaddr; de++) {
	307	if (!de->inode)
	308	continue;
	309	/* check for . and .. */
	310	if (de->name[0] != '.')
	311	goto not_empty;
	312	if (!de->name[1]) {
	313	if (de->inode == cpu_to_fs16(SYSV_SB(sb),
	314	inode->i_ino))
	315	continue;
	316	goto not_empty;
	317	}
	318	if (de->name[1] != '.' \|\| de->name[2])
	319	goto not_empty;
	320	}
	321	dir_put_page(page);
	322	}
	323	return 1;
	324
	325	not_empty:
	326	dir_put_page(page);
	327	return 0;
	328	}
	329
	330	/* Releases the page */
	331	void sysv_set_link(struct sysv_dir_entry de, struct page page,
	332	struct inode *inode)
	333	{
f4e420dc	334	struct inode *dir = page->mapping->host;
26a6441a NP	335	loff_t pos = page_offset(page) +
26a6441a NP	336	(char )de-(char)page_address(page);
1da177e4 LT	337	int err;
	338
	339	lock_page(page);
f4e420dc	340	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	341	BUG_ON(err);
1da177e4	342	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
26a6441a	343	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	344	dir_put_page(page);
	345	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
	346	mark_inode_dirty(dir);
	347	}
	348
	349	struct sysv_dir_entry * sysv_dotdot (struct inode dir, struct page *p)
	350	{
	351	struct page *page = dir_get_page(dir, 0);
	352	struct sysv_dir_entry *de = NULL;
	353
	354	if (!IS_ERR(page)) {
	355	de = (struct sysv_dir_entry*) page_address(page) + 1;
	356	*p = page;
	357	}
	358	return de;
	359	}
	360
	361	ino_t sysv_inode_by_name(struct dentry *dentry)
	362	{
	363	struct page *page;
	364	struct sysv_dir_entry *de = sysv_find_entry (dentry, &page);
	365	ino_t res = 0;
	366
	367	if (de) {
	368	res = fs16_to_cpu(SYSV_SB(dentry->d_sb), de->inode);
	369	dir_put_page(page);
	370	}
	371	return res;
	372	}