[linux-2.6-block.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,
};

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

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

	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);
	}
	unlock_page(page);
}

static int sysv_handle_dirsync(struct inode *dir)
{
	int err;

	err = filemap_write_and_wait(dir->i_mapping);
	if (!err)
		err = sync_inode_metadata(dir, 1);
	return err;
}

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

		kaddr = dir_get_page(inode, n, &page);
		if (IS_ERR(kaddr))
			continue;
		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 = dir_get_page(dir, n, &page);

		if (!IS_ERR(kaddr)) {
			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++) {
		kaddr = dir_get_page(dir, n, &page);
		if (IS_ERR(kaddr))
			return PTR_ERR(kaddr);
		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) + offset_in_page(de);
	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);
	dir_commit_chunk(page, pos, SYSV_DIRSIZE);
	dir->i_mtime = dir->i_ctime = current_time(dir);
	mark_inode_dirty(dir);
	err = sysv_handle_dirsync(dir);
out_page:
	dir_put_page(page);
	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;
	loff_t pos = page_offset(page) + offset_in_page(de);
	int err;

	lock_page(page);
	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
	BUG_ON(err);
	de->inode = 0;
	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 sysv_handle_dirsync(inode);
}

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);
	dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
	err = sysv_handle_dirsync(inode);
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;

		kaddr = dir_get_page(inode, i, &page);
		if (IS_ERR(kaddr))
			continue;

		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) + offset_in_page(de);
	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);
	dir_commit_chunk(page, pos, SYSV_DIRSIZE);
	dir_put_page(page);
	dir->i_mtime = dir->i_ctime = current_time(dir);
	mark_inode_dirty(dir);
	sysv_handle_dirsync(inode);
}

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

	if (IS_ERR(de))
		return NULL;
	/* ".." is the second directory entry */
	return de + 1;
}

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	};
1da177e4 LT	30
c26ddc49	31	inline void dir_put_page(struct page *page)
1da177e4 LT	32	{
1da177e4 LT	33	kunmap(page);
09cbfeaf	34	put_page(page);
1da177e4 LT	35	}
1da177e4 LT	36
4309093e	37	static void 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	41
26a6441a NP	42	block_write_end(NULL, mapping, pos, len, len, page, NULL);
	43	if (pos+len > dir->i_size) {
	44	i_size_write(dir, pos+len);
	45	mark_inode_dirty(dir);
	46	}
4309093e CH	47	unlock_page(page);
	48	}
	49
	50	static int sysv_handle_dirsync(struct inode *dir)
	51	{
	52	int err;
	53
	54	err = filemap_write_and_wait(dir->i_mapping);
	55	if (!err)
	56	err = sync_inode_metadata(dir, 1);
1da177e4 LT	57	return err;
	58	}
	59
8dd6c7b2	60	static void dir_get_page(struct inode dir, unsigned long n, struct page **p)
1da177e4 LT	61	{
1da177e4 LT	62	struct address_space *mapping = dir->i_mapping;
090d2b18	63	struct page *page = read_mapping_page(mapping, n, NULL);
8dd6c7b2 FDF	64	if (IS_ERR(page))
	65	return ERR_CAST(page);
	66	kmap(page);
	67	*p = page;
	68	return page_address(page);
1da177e4 LT	69	}
1da177e4 LT	70
80886298	71	static int sysv_readdir(struct file file, struct dir_context ctx)
1da177e4	72	{
80886298 AV	73	unsigned long pos = ctx->pos;
80886298 AV	74	struct inode *inode = file_inode(file);
1da177e4	75	struct super_block *sb = inode->i_sb;
1da177e4	76	unsigned long npages = dir_pages(inode);
80886298 AV	77	unsigned offset;
80886298 AV	78	unsigned long n;
1da177e4	79
80886298	80	ctx->pos = pos = (pos + SYSV_DIRSIZE-1) & ~(SYSV_DIRSIZE-1);
1da177e4	81	if (pos >= inode->i_size)
80886298 AV	82	return 0;
80886298 AV	83
09cbfeaf KS	84	offset = pos & ~PAGE_MASK;
09cbfeaf KS	85	n = pos >> PAGE_SHIFT;
1da177e4 LT	86
	87	for ( ; n < npages; n++, offset = 0) {
	88	char kaddr, limit;
	89	struct sysv_dir_entry *de;
8dd6c7b2	90	struct page *page;
1da177e4	91
8dd6c7b2 FDF	92	kaddr = dir_get_page(inode, n, &page);
8dd6c7b2 FDF	93	if (IS_ERR(kaddr))
1da177e4	94	continue;
1da177e4	95	de = (struct sysv_dir_entry *)(kaddr+offset);
09cbfeaf	96	limit = kaddr + PAGE_SIZE - SYSV_DIRSIZE;
80886298	97	for ( ;(char)de <= limit; de++, ctx->pos += sizeof(de)) {
1da177e4	98	char *name = de->name;
1da177e4 LT	99
	100	if (!de->inode)
	101	continue;
	102
80886298	103	if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
1da177e4	104	fs16_to_cpu(SYSV_SB(sb), de->inode),
80886298	105	DT_UNKNOWN)) {
1da177e4	106	dir_put_page(page);
80886298	107	return 0;
1da177e4 LT	108	}
	109	}
	110	dir_put_page(page);
	111	}
1da177e4 LT	112	return 0;
	113	}
	114
	115	/* compare strings: name[0..len-1] (not zero-terminated) and
	116	* buffer[0..] (filled with zeroes up to buffer[0..maxlen-1])
	117	*/
	118	static inline int namecompare(int len, int maxlen,
	119	const char * name, const char * buffer)
	120	{
	121	if (len < maxlen && buffer[len])
	122	return 0;
	123	return !memcmp(name, buffer, len);
	124	}
	125
	126	/*
	127	* sysv_find_entry()
	128	*
	129	* finds an entry in the specified directory with the wanted name. It
	130	* returns the cache buffer in which the entry was found, and the entry
	131	* itself (as a parameter - res_dir). It does NOT read the inode of the
	132	* entry - you'll have to do that yourself if you want to.
	133	*/
	134	struct sysv_dir_entry sysv_find_entry(struct dentry dentry, struct page **res_page)
	135	{
	136	const char * name = dentry->d_name.name;
	137	int namelen = dentry->d_name.len;
2b0143b5	138	struct inode * dir = d_inode(dentry->d_parent);
1da177e4 LT	139	unsigned long start, n;
	140	unsigned long npages = dir_pages(dir);
	141	struct page *page = NULL;
	142	struct sysv_dir_entry *de;
	143
	144	*res_page = NULL;
	145
	146	start = SYSV_I(dir)->i_dir_start_lookup;
	147	if (start >= npages)
	148	start = 0;
	149	n = start;
	150
	151	do {
8dd6c7b2 FDF	152	char *kaddr = dir_get_page(dir, n, &page);
	153
	154	if (!IS_ERR(kaddr)) {
	155	de = (struct sysv_dir_entry *)kaddr;
09cbfeaf	156	kaddr += PAGE_SIZE - SYSV_DIRSIZE;
1da177e4 LT	157	for ( ; (char *) de <= kaddr ; de++) {
	158	if (!de->inode)
	159	continue;
	160	if (namecompare(namelen, SYSV_NAMELEN,
	161	name, de->name))
	162	goto found;
	163	}
404e7812	164	dir_put_page(page);
1da177e4	165	}
1da177e4 LT	166
	167	if (++n >= npages)
	168	n = 0;
	169	} while (n != start);
	170
	171	return NULL;
	172
	173	found:
	174	SYSV_I(dir)->i_dir_start_lookup = n;
	175	*res_page = page;
	176	return de;
	177	}
	178
	179	int sysv_add_link(struct dentry dentry, struct inode inode)
	180	{
2b0143b5	181	struct inode *dir = d_inode(dentry->d_parent);
1da177e4 LT	182	const char * name = dentry->d_name.name;
	183	int namelen = dentry->d_name.len;
	184	struct page *page = NULL;
	185	struct sysv_dir_entry * de;
	186	unsigned long npages = dir_pages(dir);
	187	unsigned long n;
	188	char *kaddr;
26a6441a	189	loff_t pos;
1da177e4 LT	190	int err;
	191
	192	/* We take care of directory expansion in the same loop */
	193	for (n = 0; n <= npages; n++) {
8dd6c7b2 FDF	194	kaddr = dir_get_page(dir, n, &page);
	195	if (IS_ERR(kaddr))
	196	return PTR_ERR(kaddr);
1da177e4	197	de = (struct sysv_dir_entry *)kaddr;
09cbfeaf	198	kaddr += PAGE_SIZE - SYSV_DIRSIZE;
1da177e4 LT	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:
4bb1a137	213	pos = page_offset(page) + offset_in_page(de);
1da177e4	214	lock_page(page);
f4e420dc	215	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
1da177e4 LT	216	if (err)
	217	goto out_unlock;
	218	memcpy (de->name, name, namelen);
	219	memset (de->name + namelen, 0, SYSV_DIRSIZE - namelen - 2);
	220	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
4309093e	221	dir_commit_chunk(page, pos, SYSV_DIRSIZE);
02027d42	222	dir->i_mtime = dir->i_ctime = current_time(dir);
1da177e4	223	mark_inode_dirty(dir);
4309093e	224	err = sysv_handle_dirsync(dir);
1da177e4 LT	225	out_page:
1da177e4 LT	226	dir_put_page(page);
1da177e4 LT	227	return err;
	228	out_unlock:
	229	unlock_page(page);
	230	goto out_page;
	231	}
	232
	233	int sysv_delete_entry(struct sysv_dir_entry de, struct page page)
	234	{
f4e420dc	235	struct inode *inode = page->mapping->host;
4bb1a137	236	loff_t pos = page_offset(page) + offset_in_page(de);
1da177e4 LT	237	int err;
	238
	239	lock_page(page);
f4e420dc	240	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	241	BUG_ON(err);
1da177e4	242	de->inode = 0;
4309093e	243	dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4	244	dir_put_page(page);
02027d42	245	inode->i_ctime = inode->i_mtime = current_time(inode);
1da177e4	246	mark_inode_dirty(inode);
4309093e	247	return sysv_handle_dirsync(inode);
1da177e4 LT	248	}
	249
	250	int sysv_make_empty(struct inode inode, struct inode dir)
	251	{
f4e420dc	252	struct page *page = grab_cache_page(inode->i_mapping, 0);
1da177e4 LT	253	struct sysv_dir_entry * de;
	254	char *base;
	255	int err;
	256
	257	if (!page)
	258	return -ENOMEM;
f4e420dc	259	err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
1da177e4 LT	260	if (err) {
	261	unlock_page(page);
	262	goto fail;
	263	}
26a6441a	264	kmap(page);
1da177e4 LT	265
1da177e4 LT	266	base = (char*)page_address(page);
09cbfeaf	267	memset(base, 0, PAGE_SIZE);
1da177e4 LT	268
	269	de = (struct sysv_dir_entry *) base;
	270	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
	271	strcpy(de->name,".");
	272	de++;
	273	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
	274	strcpy(de->name,"..");
	275
26a6441a	276	kunmap(page);
4309093e CH	277	dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
4309093e CH	278	err = sysv_handle_dirsync(inode);
1da177e4	279	fail:
09cbfeaf	280	put_page(page);
1da177e4 LT	281	return err;
	282	}
	283
	284	/*
	285	* routine to check that the specified directory is empty (for rmdir)
	286	*/
	287	int sysv_empty_dir(struct inode * inode)
	288	{
	289	struct super_block *sb = inode->i_sb;
	290	struct page *page = NULL;
	291	unsigned long i, npages = dir_pages(inode);
	292
	293	for (i = 0; i < npages; i++) {
	294	char *kaddr;
	295	struct sysv_dir_entry * de;
1da177e4	296
8dd6c7b2 FDF	297	kaddr = dir_get_page(inode, i, &page);
8dd6c7b2 FDF	298	if (IS_ERR(kaddr))
1da177e4 LT	299	continue;
1da177e4 LT	300
1da177e4	301	de = (struct sysv_dir_entry *)kaddr;
09cbfeaf	302	kaddr += PAGE_SIZE-SYSV_DIRSIZE;
1da177e4 LT	303
	304	for ( ;(char *)de <= kaddr; de++) {
	305	if (!de->inode)
	306	continue;
	307	/* check for . and .. */
	308	if (de->name[0] != '.')
	309	goto not_empty;
	310	if (!de->name[1]) {
	311	if (de->inode == cpu_to_fs16(SYSV_SB(sb),
	312	inode->i_ino))
	313	continue;
	314	goto not_empty;
	315	}
	316	if (de->name[1] != '.' \|\| de->name[2])
	317	goto not_empty;
	318	}
	319	dir_put_page(page);
	320	}
	321	return 1;
	322
	323	not_empty:
	324	dir_put_page(page);
	325	return 0;
	326	}
	327
	328	/* Releases the page */
	329	void sysv_set_link(struct sysv_dir_entry de, struct page page,
	330	struct inode *inode)
	331	{
f4e420dc	332	struct inode *dir = page->mapping->host;
4bb1a137	333	loff_t pos = page_offset(page) + offset_in_page(de);
1da177e4 LT	334	int err;
	335
	336	lock_page(page);
f4e420dc	337	err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
d6735bfc	338	BUG_ON(err);
1da177e4	339	de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
4309093e	340	dir_commit_chunk(page, pos, SYSV_DIRSIZE);
1da177e4	341	dir_put_page(page);
02027d42	342	dir->i_mtime = dir->i_ctime = current_time(dir);
1da177e4	343	mark_inode_dirty(dir);
4309093e	344	sysv_handle_dirsync(inode);
1da177e4 LT	345	}
1da177e4 LT	346
8dd6c7b2	347	struct sysv_dir_entry sysv_dotdot(struct inode dir, struct page **p)
1da177e4	348	{
8dd6c7b2	349	struct sysv_dir_entry *de = dir_get_page(dir, 0, p);
1da177e4	350
8dd6c7b2 FDF	351	if (IS_ERR(de))
	352	return NULL;
	353	/* ".." is the second directory entry */
	354	return de + 1;
1da177e4 LT	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	}