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

// SPDX-License-Identifier: GPL-2.0
/*
 *  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_shared	= sysv_readdir,
	.fsync		= generic_file_fsync,
};

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

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);
	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_MASK;
	n = pos >> PAGE_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_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 = d_inode(dentry->d_parent);
	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_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 = d_inode(dentry->d_parent);
	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_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(dir);
	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(inode);
	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_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:
	put_page(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_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(dir);
	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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/sysv/dir.c
	4	*
	5	* minix/dir.c
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	*
	8	* coh/dir.c
	9	* Copyright (C) 1993 Pascal Haible, Bruno Haible
	10	*
	11	* sysv/dir.c
	12	* Copyright (C) 1993 Bruno Haible
	13	*
	14	* SystemV/Coherent directory handling functions
	15	*/
	16
	17	#include <linux/pagemap.h>
	18	#include <linux/highmem.h>
26a6441a	19	#include <linux/swap.h>
1da177e4 LT	20	#include "sysv.h"
1da177e4 LT	21
80886298	22	static int sysv_readdir(struct file , struct dir_context );
1da177e4	23
4b6f5d20	24	const struct file_operations sysv_dir_operations = {
5ac3455a	25	.llseek = generic_file_llseek,
1da177e4	26	.read = generic_read_dir,
3b0a3c1a	27	.iterate_shared = sysv_readdir,
1b061d92	28	.fsync = generic_file_fsync,
1da177e4 LT	29	};
	30
	31	static inline void dir_put_page(struct page *page)
	32	{
	33	kunmap(page);
09cbfeaf	34	put_page(page);
1da177e4 LT	35	}
1da177e4 LT	36
26a6441a	37	static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
1da177e4	38	{
26a6441a NP	39	struct address_space *mapping = page->mapping;
26a6441a NP	40	struct inode *dir = mapping->host;
1da177e4 LT	41	int err = 0;
1da177e4 LT	42
26a6441a NP	43	block_write_end(NULL, mapping, pos, len, len, page, NULL);
	44	if (pos+len > dir->i_size) {
	45	i_size_write(dir, pos+len);
	46	mark_inode_dirty(dir);
	47	}
1da177e4	48	if (IS_DIRSYNC(dir))
2b69c828	49	err = write_one_page(page);
1da177e4 LT	50	else
	51	unlock_page(page);
	52	return err;
	53	}
	54
	55	static struct page * dir_get_page(struct inode *dir, unsigned long n)
	56	{
	57	struct address_space *mapping = dir->i_mapping;
090d2b18	58	struct page *page = read_mapping_page(mapping, n, NULL);
6fe6900e	59	if (!IS_ERR(page))
1da177e4	60	kmap(page);
1da177e4	61	return page;
1da177e4 LT	62	}
1da177e4 LT	63
80886298	64	static int sysv_readdir(struct file file, struct dir_context ctx)
1da177e4	65	{
80886298 AV	66	unsigned long pos = ctx->pos;
80886298 AV	67	struct inode *inode = file_inode(file);
1da177e4	68	struct super_block *sb = inode->i_sb;
1da177e4	69	unsigned long npages = dir_pages(inode);
80886298 AV	70	unsigned offset;
80886298 AV	71	unsigned long n;
1da177e4	72
80886298	73	ctx->pos = pos = (pos + SYSV_DIRSIZE-1) & ~(SYSV_DIRSIZE-1);
1da177e4	74	if (pos >= inode->i_size)
80886298 AV	75	return 0;
80886298 AV	76
09cbfeaf KS	77	offset = pos & ~PAGE_MASK;
09cbfeaf KS	78	n = pos >> PAGE_SHIFT;
1da177e4 LT	79
	80	for ( ; n < npages; n++, offset = 0) {
	81	char kaddr, limit;
	82	struct sysv_dir_entry *de;
	83	struct page *page = dir_get_page(inode, n);
	84
	85	if (IS_ERR(page))
	86	continue;
	87	kaddr = (char *)page_address(page);
	88	de = (struct sysv_dir_entry *)(kaddr+offset);
09cbfeaf	89	limit = kaddr + PAGE_SIZE - SYSV_DIRSIZE;
80886298	90	for ( ;(char)de <= limit; de++, ctx->pos += sizeof(de)) {
1da177e4	91	char *name = de->name;
1da177e4 LT	92
	93	if (!de->inode)
	94	continue;
	95
80886298	96	if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
1da177e4	97	fs16_to_cpu(SYSV_SB(sb), de->inode),
80886298	98	DT_UNKNOWN)) {
1da177e4	99	dir_put_page(page);
80886298	100	return 0;
1da177e4 LT	101	}
	102	}
	103	dir_put_page(page);
	104	}
1da177e4 LT	105	return 0;
	106	}
	107
	108	/* compare strings: name[0..len-1] (not zero-terminated) and
	109	* buffer[0..] (filled with zeroes up to buffer[0..maxlen-1])
	110	*/
	111	static inline int namecompare(int len, int maxlen,
	112	const char * name, const char * buffer)
	113	{
	114	if (len < maxlen && buffer[len])
	115	return 0;
	116	return !memcmp(name, buffer, len);
	117	}
	118
	119	/*
	120	* sysv_find_entry()
	121	*
	122	* finds an entry in the specified directory with the wanted name. It
	123	* returns the cache buffer in which the entry was found, and the entry
	124	* itself (as a parameter - res_dir). It does NOT read the inode of the
	125	* entry - you'll have to do that yourself if you want to.
	126	*/
	127	struct sysv_dir_entry sysv_find_entry(struct dentry dentry, struct page **res_page)
	128	{
	129	const char * name = dentry->d_name.name;
	130	int namelen = dentry->d_name.len;
2b0143b5	131	struct inode * dir = d_inode(dentry->d_parent);
1da177e4 LT	132	unsigned long start, n;
	133	unsigned long npages = dir_pages(dir);
	134	struct page *page = NULL;
	135	struct sysv_dir_entry *de;
	136
	137	*res_page = NULL;
	138
	139	start = SYSV_I(dir)->i_dir_start_lookup;
	140	if (start >= npages)
	141	start = 0;
	142	n = start;
	143
	144	do {
	145	char *kaddr;
	146	page = dir_get_page(dir, n);
	147	if (!IS_ERR(page)) {
	148	kaddr = (char*)page_address(page);
	149	de = (struct sysv_dir_entry *) kaddr;
09cbfeaf	150	kaddr += PAGE_SIZE - SYSV_DIRSIZE;
1da177e4 LT	151	for ( ; (char *) de <= kaddr ; de++) {
	152	if (!de->inode)
	153	continue;
	154	if (namecompare(namelen, SYSV_NAMELEN,
	155	name, de->name))
	156	goto found;
	157	}
404e7812	158	dir_put_page(page);
1da177e4	159	}
1da177e4 LT	160
	161	if (++n >= npages)
	162	n = 0;
	163	} while (n != start);
	164
	165	return NULL;
	166
	167	found:
	168	SYSV_I(dir)->i_dir_start_lookup = n;
	169	*res_page = page;
	170	return de;
	171	}
	172
	173	int sysv_add_link(struct dentry dentry, struct inode inode)
	174	{
2b0143b5	175	struct inode *dir = d_inode(dentry->d_parent);
1da177e4 LT	176	const char * name = dentry->d_name.name;
	177	int namelen = dentry->d_name.len;
	178	struct page *page = NULL;
	179	struct sysv_dir_entry * de;
	180	unsigned long npages = dir_pages(dir);
	181	unsigned long n;
	182	char *kaddr;
26a6441a	183	loff_t pos;
1da177e4 LT	184	int err;
	185
	186	/* We take care of directory expansion in the same loop */
	187	for (n = 0; n <= npages; n++) {
	188	page = dir_get_page(dir, n);
	189	err = PTR_ERR(page);
	190	if (IS_ERR(page))
	191	goto out;
	192	kaddr = (char*)page_address(page);
	193	de = (struct sysv_dir_entry *)kaddr;
09cbfeaf	194	kaddr += PAGE_SIZE - SYSV_DIRSIZE;
1da177e4 LT	195	while ((char *)de <= kaddr) {
	196	if (!de->inode)
	197	goto got_it;
	198	err = -EEXIST;
	199	if (namecompare(namelen, SYSV_NAMELEN, name, de->name))
	200	goto out_page;
	201	de++;
	202	}
	203	dir_put_page(page);
	204	}
	205	BUG();
	206	return -EINVAL;
	207
	208	got_it:
26a6441a NP	209	pos = page_offset(page) +
26a6441a NP	210	(char)de - (char)page_address(page);
1da177e4	211	lock_page(page);
f4e420dc	212	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	213	if (err)
	214	goto out_unlock;
	215	memcpy (de->name, name, namelen);
	216	memset (de->name + namelen, 0, SYSV_DIRSIZE - namelen - 2);
	217	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
26a6441a	218	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
02027d42	219	dir->i_mtime = dir->i_ctime = current_time(dir);
1da177e4 LT	220	mark_inode_dirty(dir);
	221	out_page:
	222	dir_put_page(page);
	223	out:
	224	return err;
	225	out_unlock:
	226	unlock_page(page);
	227	goto out_page;
	228	}
	229
	230	int sysv_delete_entry(struct sysv_dir_entry de, struct page page)
	231	{
f4e420dc	232	struct inode *inode = page->mapping->host;
1da177e4	233	char kaddr = (char)page_address(page);
26a6441a	234	loff_t pos = page_offset(page) + (char *)de - kaddr;
1da177e4 LT	235	int err;
	236
	237	lock_page(page);
f4e420dc	238	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	239	BUG_ON(err);
1da177e4	240	de->inode = 0;
26a6441a	241	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4	242	dir_put_page(page);
02027d42	243	inode->i_ctime = inode->i_mtime = current_time(inode);
1da177e4 LT	244	mark_inode_dirty(inode);
	245	return err;
	246	}
	247
	248	int sysv_make_empty(struct inode inode, struct inode dir)
	249	{
f4e420dc	250	struct page *page = grab_cache_page(inode->i_mapping, 0);
1da177e4 LT	251	struct sysv_dir_entry * de;
	252	char *base;
	253	int err;
	254
	255	if (!page)
	256	return -ENOMEM;
f4e420dc	257	err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
1da177e4 LT	258	if (err) {
	259	unlock_page(page);
	260	goto fail;
	261	}
26a6441a	262	kmap(page);
1da177e4 LT	263
1da177e4 LT	264	base = (char*)page_address(page);
09cbfeaf	265	memset(base, 0, PAGE_SIZE);
1da177e4 LT	266
	267	de = (struct sysv_dir_entry *) base;
	268	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	269	strcpy(de->name,".");
	270	de++;
	271	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
	272	strcpy(de->name,"..");
	273
26a6441a	274	kunmap(page);
1da177e4 LT	275	err = dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
1da177e4 LT	276	fail:
09cbfeaf	277	put_page(page);
1da177e4 LT	278	return err;
	279	}
	280
	281	/*
	282	* routine to check that the specified directory is empty (for rmdir)
	283	*/
	284	int sysv_empty_dir(struct inode * inode)
	285	{
	286	struct super_block *sb = inode->i_sb;
	287	struct page *page = NULL;
	288	unsigned long i, npages = dir_pages(inode);
	289
	290	for (i = 0; i < npages; i++) {
	291	char *kaddr;
	292	struct sysv_dir_entry * de;
	293	page = dir_get_page(inode, i);
	294
	295	if (IS_ERR(page))
	296	continue;
	297
	298	kaddr = (char *)page_address(page);
	299	de = (struct sysv_dir_entry *)kaddr;
09cbfeaf	300	kaddr += PAGE_SIZE-SYSV_DIRSIZE;
1da177e4 LT	301
	302	for ( ;(char *)de <= kaddr; de++) {
	303	if (!de->inode)
	304	continue;
	305	/* check for . and .. */
	306	if (de->name[0] != '.')
	307	goto not_empty;
	308	if (!de->name[1]) {
	309	if (de->inode == cpu_to_fs16(SYSV_SB(sb),
	310	inode->i_ino))
	311	continue;
	312	goto not_empty;
	313	}
	314	if (de->name[1] != '.' \|\| de->name[2])
	315	goto not_empty;
	316	}
	317	dir_put_page(page);
	318	}
	319	return 1;
	320
	321	not_empty:
	322	dir_put_page(page);
	323	return 0;
	324	}
	325
	326	/* Releases the page */
	327	void sysv_set_link(struct sysv_dir_entry de, struct page page,
	328	struct inode *inode)
	329	{
f4e420dc	330	struct inode *dir = page->mapping->host;
26a6441a NP	331	loff_t pos = page_offset(page) +
26a6441a NP	332	(char )de-(char)page_address(page);
1da177e4 LT	333	int err;
	334
	335	lock_page(page);
f4e420dc	336	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	337	BUG_ON(err);
1da177e4	338	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
26a6441a	339	err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4	340	dir_put_page(page);
02027d42	341	dir->i_mtime = dir->i_ctime = current_time(dir);
1da177e4 LT	342	mark_inode_dirty(dir);
	343	}
	344
	345	struct sysv_dir_entry * sysv_dotdot (struct inode dir, struct page *p)
	346	{
	347	struct page *page = dir_get_page(dir, 0);
	348	struct sysv_dir_entry *de = NULL;
	349
	350	if (!IS_ERR(page)) {
	351	de = (struct sysv_dir_entry*) page_address(page) + 1;
	352	*p = page;
	353	}
	354	return de;
	355	}
	356
	357	ino_t sysv_inode_by_name(struct dentry *dentry)
	358	{
	359	struct page *page;
	360	struct sysv_dir_entry *de = sysv_find_entry (dentry, &page);
	361	ino_t res = 0;
	362
	363	if (de) {
	364	res = fs16_to_cpu(SYSV_SB(dentry->d_sb), de->inode);
	365	dir_put_page(page);
	366	}
	367	return res;
	368	}