Release 4.11 fs/minix/dir.c

/*
 *  linux/fs/minix/dir.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  minix directory handling functions
 *
 *  Updated to filesystem version 3 by Daniel Aragones
 */

#include "minix.h"
#include <linux/buffer_head.h>
#include <linux/highmem.h>
#include <linux/swap.h>


typedef struct minix_dir_entry minix_dirent;

typedef struct minix3_dir_entry minix3_dirent;

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


const struct file_operations minix_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate_shared	= minix_readdir,
	.fsync		= generic_file_fsync,
};



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
15
68.18%
1
33.33%
Linus Torvalds (pre-git)
6
27.27%
1
33.33%
Kirill A. Shutemov
1
4.55%
1
33.33%
Total
22
100.00%
3
100.00%

/*
 * Return the offset into page `page_nr' of the last valid
 * byte in that page, plus one.
 */

static unsigned

minix_last_byte(struct inode *inode, unsigned long page_nr)
{
	unsigned last_byte = PAGE_SIZE;

	if (page_nr == (inode->i_size >> PAGE_SHIFT))
		last_byte = inode->i_size & (PAGE_SIZE - 1);
	return last_byte;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
44
93.62%
1
50.00%
Kirill A. Shutemov
3
6.38%
1
50.00%
Total
47
100.00%
2
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
47
43.52%
1
11.11%
Linus Torvalds
34
31.48%
1
11.11%
Linus Torvalds (pre-git)
17
15.74%
4
44.44%
Andrew Morton
10
9.26%
3
33.33%
Total
108
100.00%
9
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
46
82.14%
1
25.00%
Linus Torvalds (pre-git)
9
16.07%
2
50.00%
Pekka J Enberg
1
1.79%
1
25.00%
Total
56
100.00%
4
100.00%



static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
{
	return (void*)((char*)de + sbi->s_dirsize);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
34
100.00%
1
100.00%
Total
34
100.00%
1
100.00%



static int minix_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	struct super_block *sb = inode->i_sb;
	struct minix_sb_info *sbi = minix_sb(sb);
	unsigned chunk_size = sbi->s_dirsize;
	unsigned long npages = dir_pages(inode);
	unsigned long pos = ctx->pos;
	unsigned offset;
	unsigned long n;

	ctx->pos = pos = ALIGN(pos, chunk_size);
	if (pos >= inode->i_size)
		return 0;

	offset = pos & ~PAGE_MASK;
	n = pos >> PAGE_SHIFT;

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

		if (IS_ERR(page))
			continue;
		kaddr = (char *)page_address(page);
		p = kaddr+offset;
		limit = kaddr + minix_last_byte(inode, n) - chunk_size;
		for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
			const char *name;
			__u32 inumber;
			if (sbi->s_version == MINIX_V3) {
				minix3_dirent *de3 = (minix3_dirent *)p;
				name = de3->name;
				inumber = de3->inode;
	 		} else {
				minix_dirent *de = (minix_dirent *)p;
				name = de->name;
				inumber = de->inode;
			}
			if (inumber) {
				unsigned l = strnlen(name, sbi->s_namelen);
				if (!dir_emit(ctx, name, l,
					      inumber, DT_UNKNOWN)) {
					dir_put_page(page);
					return 0;
				}
			}
			ctx->pos += chunk_size;
		}
		dir_put_page(page);
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
199
60.30%
1
14.29%
Al Viro
69
20.91%
2
28.57%
Andries E. Brouwer
50
15.15%
1
14.29%
Andrew Morton
6
1.82%
1
14.29%
Dan Carpenter
4
1.21%
1
14.29%
Kirill A. Shutemov
2
0.61%
1
14.29%
Total
330
100.00%
7
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
48
100.00%
1
100.00%
Total
48
100.00%
1
100.00%

/*
 *      minix_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.
 */


minix_dirent *minix_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);
	struct super_block * sb = dir->i_sb;
	struct minix_sb_info * sbi = minix_sb(sb);
	unsigned long n;
	unsigned long npages = dir_pages(dir);
	struct page *page = NULL;
	char *p;

	char *namx;
	__u32 inumber;
	*res_page = NULL;

	for (n = 0; n < npages; n++) {
		char *kaddr, *limit;

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

		kaddr = (char*)page_address(page);
		limit = kaddr + minix_last_byte(dir, n) - sbi->s_dirsize;
		for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
			if (sbi->s_version == MINIX_V3) {
				minix3_dirent *de3 = (minix3_dirent *)p;
				namx = de3->name;
				inumber = de3->inode;
 			} else {
				minix_dirent *de = (minix_dirent *)p;
				namx = de->name;
				inumber = de->inode;
			}
			if (!inumber)
				continue;
			if (namecompare(namelen, sbi->s_namelen, name, namx))
				goto found;
		}
		dir_put_page(page);
	}
	return NULL;

found:
	*res_page = page;
	return (minix_dirent *)p;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
198
67.58%
1
20.00%
Andries E. Brouwer
83
28.33%
1
20.00%
Andrew Morton
6
2.05%
1
20.00%
Brian Gerst
3
1.02%
1
20.00%
David Howells
3
1.02%
1
20.00%
Total
293
100.00%
5
100.00%



int minix_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 super_block * sb = dir->i_sb;
	struct minix_sb_info * sbi = minix_sb(sb);
	struct page *page = NULL;
	unsigned long npages = dir_pages(dir);
	unsigned long n;
	char *kaddr, *p;
	minix_dirent *de;
	minix3_dirent *de3;
	loff_t pos;
	int err;
	char *namx = NULL;
	__u32 inumber;

	/*
         * We take care of directory expansion in the same loop
         * This code plays outside i_size, so it locks the page
         * to protect that region.
         */
	for (n = 0; n <= npages; n++) {
		char *limit, *dir_end;

		page = dir_get_page(dir, n);
		err = PTR_ERR(page);
		if (IS_ERR(page))
			goto out;
		lock_page(page);
		kaddr = (char*)page_address(page);
		dir_end = kaddr + minix_last_byte(dir, n);
		limit = kaddr + PAGE_SIZE - sbi->s_dirsize;
		for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
			de = (minix_dirent *)p;
			de3 = (minix3_dirent *)p;
			if (sbi->s_version == MINIX_V3) {
				namx = de3->name;
				inumber = de3->inode;
		 	} else {
  				namx = de->name;
				inumber = de->inode;
			}
			if (p == dir_end) {
				/* We hit i_size */
				if (sbi->s_version == MINIX_V3)
					de3->inode = 0;
		 		else
					de->inode = 0;
				goto got_it;
			}
			if (!inumber)
				goto got_it;
			err = -EEXIST;
			if (namecompare(namelen, sbi->s_namelen, name, namx))
				goto out_unlock;
		}
		unlock_page(page);
		dir_put_page(page);
	}
	BUG();
	return -EINVAL;

got_it:
	pos = page_offset(page) + p - (char *)page_address(page);
	err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
	if (err)
		goto out_unlock;
	memcpy (namx, name, namelen);
	if (sbi->s_version == MINIX_V3) {
		memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
		de3->inode = inode->i_ino;
	} else {
		memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
		de->inode = inode->i_ino;
	}
	err = dir_commit_chunk(page, pos, sbi->s_dirsize);
	dir->i_mtime = dir->i_ctime = current_time(dir);
	mark_inode_dirty(dir);
out_put:
	dir_put_page(page);
out:
	return err;
out_unlock:
	unlock_page(page);
	goto out_put;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
282
54.02%
1
9.09%
Andries E. Brouwer
151
28.93%
1
9.09%
Andrew Morton
59
11.30%
2
18.18%
Nicholas Piggin
15
2.87%
1
9.09%
Deepa Dinamani
4
0.77%
1
9.09%
Brian Gerst
3
0.57%
1
9.09%
Evgeniy Dushistov
3
0.57%
1
9.09%
David Howells
3
0.57%
1
9.09%
Christoph Hellwig
1
0.19%
1
9.09%
Kirill A. Shutemov
1
0.19%
1
9.09%
Total
522
100.00%
11
100.00%



int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
{
	struct inode *inode = page->mapping->host;
	char *kaddr = page_address(page);
	loff_t pos = page_offset(page) + (char*)de - kaddr;
	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	unsigned len = sbi->s_dirsize;
	int err;

	lock_page(page);
	err = minix_prepare_chunk(page, pos, len);
	if (err == 0) {
		if (sbi->s_version == MINIX_V3)
			((minix3_dirent *) de)->inode = 0;
		else
			de->inode = 0;
		err = dir_commit_chunk(page, pos, len);
	} else {
		unlock_page(page);
	}
	dir_put_page(page);
	inode->i_ctime = inode->i_mtime = current_time(inode);
	mark_inode_dirty(inode);
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
108
63.91%
1
11.11%
Doug Graham
30
17.75%
1
11.11%
Nicholas Piggin
12
7.10%
1
11.11%
Andrew Morton
8
4.73%
3
33.33%
Christoph Hellwig
4
2.37%
1
11.11%
Deepa Dinamani
4
2.37%
1
11.11%
Brian Gerst
3
1.78%
1
11.11%
Total
169
100.00%
9
100.00%



int minix_make_empty(struct inode *inode, struct inode *dir)
{
	struct page *page = grab_cache_page(inode->i_mapping, 0);
	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	char *kaddr;
	int err;

	if (!page)
		return -ENOMEM;
	err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
	if (err) {
		unlock_page(page);
		goto fail;
	}

	kaddr = kmap_atomic(page);
	memset(kaddr, 0, PAGE_SIZE);

	if (sbi->s_version == MINIX_V3) {
		minix3_dirent *de3 = (minix3_dirent *)kaddr;

		de3->inode = inode->i_ino;
		strcpy(de3->name, ".");
		de3 = minix_next_entry(de3, sbi);
		de3->inode = dir->i_ino;
		strcpy(de3->name, "..");
	} else {
		minix_dirent *de = (minix_dirent *)kaddr;

		de->inode = inode->i_ino;
		strcpy(de->name, ".");
		de = minix_next_entry(de, sbi);
		de->inode = dir->i_ino;
		strcpy(de->name, "..");
	}
	kunmap_atomic(kaddr);

	err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
fail:
	put_page(page);
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
153
60.96%
1
14.29%
Andries E. Brouwer
71
28.29%
1
14.29%
Andrew Morton
17
6.77%
2
28.57%
Christoph Hellwig
5
1.99%
1
14.29%
Brian Gerst
3
1.20%
1
14.29%
Kirill A. Shutemov
2
0.80%
1
14.29%
Total
251
100.00%
7
100.00%

/*
 * routine to check that the specified directory is empty (for rmdir)
 */


int minix_empty_dir(struct inode * inode)
{
	struct page *page = NULL;
	unsigned long i, npages = dir_pages(inode);
	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	char *name;
	__u32 inumber;

	for (i = 0; i < npages; i++) {
		char *p, *kaddr, *limit;

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

		kaddr = (char *)page_address(page);
		limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
		for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
			if (sbi->s_version == MINIX_V3) {
				minix3_dirent *de3 = (minix3_dirent *)p;
				name = de3->name;
				inumber = de3->inode;
			} else {
				minix_dirent *de = (minix_dirent *)p;
				name = de->name;
				inumber = de->inode;
			}

			if (inumber != 0) {
				/* check for . and .. */
				if (name[0] != '.')
					goto not_empty;
				if (!name[1]) {
					if (inumber != inode->i_ino)
						goto not_empty;
				} else if (name[1] != '.')
					goto not_empty;
				else if (name[2])
					goto not_empty;
			}
		}
		dir_put_page(page);
	}
	return 1;

not_empty:
	dir_put_page(page);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
181
65.34%
1
25.00%
Andries E. Brouwer
87
31.41%
1
25.00%
Andrew Morton
6
2.17%
1
25.00%
Brian Gerst
3
1.08%
1
25.00%
Total
277
100.00%
4
100.00%

/* Releases the page */


void minix_set_link(struct minix_dir_entry *de, struct page *page,
	struct inode *inode)
{
	struct inode *dir = page->mapping->host;
	struct minix_sb_info *sbi = minix_sb(dir->i_sb);
	loff_t pos = page_offset(page) +
			(char *)de-(char*)page_address(page);
	int err;

	lock_page(page);

	err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
	if (err == 0) {
		if (sbi->s_version == MINIX_V3)
			((minix3_dirent *) de)->inode = inode->i_ino;
		else
			de->inode = inode->i_ino;
		err = dir_commit_chunk(page, pos, sbi->s_dirsize);
	} else {
		unlock_page(page);
	}
	dir_put_page(page);
	dir->i_mtime = dir->i_ctime = current_time(dir);
	mark_inode_dirty(dir);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
108
63.53%
1
11.11%
Doug Graham
23
13.53%
1
11.11%
Nicholas Piggin
20
11.76%
1
11.11%
Andrew Morton
8
4.71%
3
33.33%
Deepa Dinamani
4
2.35%
1
11.11%
Christoph Hellwig
4
2.35%
1
11.11%
Brian Gerst
3
1.76%
1
11.11%
Total
170
100.00%
9
100.00%



struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
{
	struct page *page = dir_get_page(dir, 0);
	struct minix_sb_info *sbi = minix_sb(dir->i_sb);
	struct minix_dir_entry *de = NULL;

	if (!IS_ERR(page)) {
		de = minix_next_entry(page_address(page), sbi);
		*p = page;
	}
	return de;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
72
91.14%
1
25.00%
Linus Torvalds (pre-git)
4
5.06%
2
50.00%
Brian Gerst
3
3.80%
1
25.00%
Total
79
100.00%
4
100.00%



ino_t minix_inode_by_name(struct dentry *dentry)
{
	struct page *page;
	struct minix_dir_entry *de = minix_find_entry(dentry, &page);
	ino_t res = 0;

	if (de) {
		struct address_space *mapping = page->mapping;
		struct inode *inode = mapping->host;
		struct minix_sb_info *sbi = minix_sb(inode->i_sb);

		if (sbi->s_version == MINIX_V3)
			res = ((minix3_dirent *) de)->inode;
		else
			res = de->inode;
		dir_put_page(page);
	}
	return res;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Doug Graham
51
49.04%
1
25.00%
Linus Torvalds
50
48.08%
1
25.00%
Linus Torvalds (pre-git)
3
2.88%
2
50.00%
Total
104
100.00%
4
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
1536
59.60%
1
2.86%
Andries E. Brouwer
448
17.38%
1
2.86%
Andrew Morton
168
6.52%
6
17.14%
Doug Graham
104
4.04%
1
2.86%
Nicholas Piggin
98
3.80%
1
2.86%
Al Viro
78
3.03%
5
14.29%
Linus Torvalds (pre-git)
65
2.52%
8
22.86%
Brian Gerst
21
0.81%
1
2.86%
Christoph Hellwig
15
0.58%
2
5.71%
Deepa Dinamani
12
0.47%
1
2.86%
Kirill A. Shutemov
9
0.35%
1
2.86%
David Howells
6
0.23%
1
2.86%
Art Haas
6
0.23%
1
2.86%
Dan Carpenter
4
0.16%
1
2.86%
Evgeniy Dushistov
3
0.12%
1
2.86%
Dave Hansen
2
0.08%
1
2.86%
Arjan van de Ven
1
0.04%
1
2.86%
Pekka J Enberg
1
0.04%
1
2.86%
Total
2577
100.00%
35
100.00%
Directory: fs/minix

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