Release 4.11 fs/ramfs/inode.c

/*
 * Resizable simple ram filesystem for Linux.
 *
 * Copyright (C) 2000 Linus Torvalds.
 *               2000 Transmeta Corp.
 *
 * Usage limits added by David Gibson, Linuxcare Australia.
 * This file is released under the GPL.
 */

/*
 * NOTE! This filesystem is probably most useful
 * not as a real filesystem, but as an example of
 * how virtual filesystems can be written.
 *
 * It doesn't get much simpler than this. Consider
 * that this file implements the full semantics of
 * a POSIX-compliant read-write filesystem.
 *
 * Note in particular how the filesystem does not
 * need to implement any data structures of its own
 * to keep track of the virtual data: using the VFS
 * caches is sufficient.
 */

#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/ramfs.h>
#include <linux/sched.h>
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include "internal.h"


#define RAMFS_DEFAULT_MODE	0755


static const struct super_operations ramfs_ops;

static const struct inode_operations ramfs_dir_inode_operations;


static const struct address_space_operations ramfs_aops = {
	.readpage	= simple_readpage,
	.write_begin	= simple_write_begin,
	.write_end	= simple_write_end,
	.set_page_dirty	= __set_page_dirty_no_writeback,
};



struct inode *ramfs_get_inode(struct super_block *sb,
				const struct inode *dir, umode_t mode, dev_t dev)
{
	struct inode * inode = new_inode(sb);

	if (inode) {
		inode->i_ino = get_next_ino();
		inode_init_owner(inode, dir, mode);
		inode->i_mapping->a_ops = &ramfs_aops;
		mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
		mapping_set_unevictable(inode->i_mapping);
		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
		switch (mode & S_IFMT) {
		default:
			init_special_inode(inode, mode, dev);
			break;
		case S_IFREG:
			inode->i_op = &ramfs_file_inode_operations;
			inode->i_fop = &ramfs_file_operations;
			break;
		case S_IFDIR:
			inode->i_op = &ramfs_dir_inode_operations;
			inode->i_fop = &simple_dir_operations;

			/* directory inodes start off with i_nlink == 2 (for "." entry) */
			inc_nlink(inode);
			break;
		case S_IFLNK:
			inode->i_op = &page_symlink_inode_operations;
			inode_nohighmem(inode);
			break;
		}
	}
	return inode;
}

Contributors
Person
Tokens
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CommitProp
Linus Torvalds (pre-git)
116
65.17%
2
13.33%
Dmitriy Monakhov
12
6.74%
1
6.67%
Mel Gorman
9
5.06%
1
6.67%
Hirofumi Ogawa
7
3.93%
1
6.67%
Al Viro
7
3.93%
3
20.00%
Christoph Hellwig
7
3.93%
1
6.67%
Lee Schermerhorn
7
3.93%
1
6.67%
Deepa Dinamani
4
2.25%
1
6.67%
Dave Hansen
3
1.69%
1
6.67%
Linus Torvalds
3
1.69%
1
6.67%
Andrew Morton
2
1.12%
1
6.67%
Andries E. Brouwer
1
0.56%
1
6.67%
Total
178
100.00%
15
100.00%

/*
 * File creation. Allocate an inode, and we're done..
 */
/* SMP-safe */

static int

ramfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
{
	struct inode * inode = ramfs_get_inode(dir->i_sb, dir, mode, dev);
	int error = -ENOSPC;

	if (inode) {
		d_instantiate(dentry, inode);
		dget(dentry);	/* Extra count - pin the dentry in core */
		error = 0;
		dir->i_mtime = dir->i_ctime = current_time(dir);
	}
	return error;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
68
80.00%
1
16.67%
Andrew Morton
9
10.59%
1
16.67%
Deepa Dinamani
4
4.71%
1
16.67%
Dmitriy Monakhov
2
2.35%
1
16.67%
Andries E. Brouwer
1
1.18%
1
16.67%
Al Viro
1
1.18%
1
16.67%
Total
85
100.00%
6
100.00%



static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
	int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0);
	if (!retval)
		inc_nlink(dir);
	return retval;
}

Contributors
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Tokens
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CommitProp
Linus Torvalds (pre-git)
31
64.58%
1
25.00%
Linus Torvalds
13
27.08%
1
25.00%
Dave Hansen
3
6.25%
1
25.00%
Al Viro
1
2.08%
1
25.00%
Total
48
100.00%
4
100.00%



static int ramfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
{
	return ramfs_mknod(dir, dentry, mode | S_IFREG, 0);
}

Contributors
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Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
32
88.89%
1
25.00%
Al Viro
3
8.33%
2
50.00%
Trond Myklebust
1
2.78%
1
25.00%
Total
36
100.00%
4
100.00%



static int ramfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
{
	struct inode *inode;
	int error = -ENOSPC;

	inode = ramfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
	if (inode) {
		int l = strlen(symname)+1;
		error = page_symlink(inode, symname, l);
		if (!error) {
			d_instantiate(dentry, inode);
			dget(dentry);
			dir->i_mtime = dir->i_ctime = current_time(dir);
		} else
			iput(inode);
	}
	return error;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
63
53.85%
1
16.67%
Al Viro
38
32.48%
1
16.67%
Peter Staubach
9
7.69%
1
16.67%
Deepa Dinamani
4
3.42%
1
16.67%
Dmitriy Monakhov
2
1.71%
1
16.67%
Andrew Morton
1
0.85%
1
16.67%
Total
117
100.00%
6
100.00%


static const struct inode_operations ramfs_dir_inode_operations = {
	.create		= ramfs_create,
	.lookup		= simple_lookup,
	.link		= simple_link,
	.unlink		= simple_unlink,
	.symlink	= ramfs_symlink,
	.mkdir		= ramfs_mkdir,
	.rmdir		= simple_rmdir,
	.mknod		= ramfs_mknod,
	.rename		= simple_rename,
};


static const struct super_operations ramfs_ops = {
	.statfs		= simple_statfs,
	.drop_inode	= generic_delete_inode,
	.show_options	= generic_show_options,
};


struct ramfs_mount_opts {
	
umode_t mode;
};

enum {
	
Opt_mode,
	
Opt_err
};


static const match_table_t tokens = {
	{Opt_mode, "mode=%o"},
	{Opt_err, NULL}
};


struct ramfs_fs_info {
	
struct ramfs_mount_opts mount_opts;
};



static int ramfs_parse_options(char *data, struct ramfs_mount_opts *opts)
{
	substring_t args[MAX_OPT_ARGS];
	int option;
	int token;
	char *p;

	opts->mode = RAMFS_DEFAULT_MODE;

	while ((p = strsep(&data, ",")) != NULL) {
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_mode:
			if (match_octal(&args[0], &option))
				return -EINVAL;
			opts->mode = option & S_IALLUGO;
			break;
		/*
                 * We might like to report bad mount options here;
                 * but traditionally ramfs has ignored all mount options,
                 * and as it is used as a !CONFIG_SHMEM simple substitute
                 * for tmpfs, better continue to ignore other mount options.
                 */
		}
	}

	return 0;
}

Contributors
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Tokens
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CommitProp
Fengguang Wu
112
99.12%
1
50.00%
Mike Frysinger
1
0.88%
1
50.00%
Total
113
100.00%
2
100.00%



int ramfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct ramfs_fs_info *fsi;
	struct inode *inode;
	int err;

	save_mount_options(sb, data);

	fsi = kzalloc(sizeof(struct ramfs_fs_info), GFP_KERNEL);
	sb->s_fs_info = fsi;
	if (!fsi)
		return -ENOMEM;

	err = ramfs_parse_options(data, &fsi->mount_opts);
	if (err)
		return err;

	sb->s_maxbytes		= MAX_LFS_FILESIZE;
	sb->s_blocksize		= PAGE_SIZE;
	sb->s_blocksize_bits	= PAGE_SHIFT;
	sb->s_magic		= RAMFS_MAGIC;
	sb->s_op		= &ramfs_ops;
	sb->s_time_gran		= 1;

	inode = ramfs_get_inode(sb, NULL, S_IFDIR | fsi->mount_opts.mode, 0);
	sb->s_root = d_make_root(inode);
	if (!sb->s_root)
		return -ENOMEM;

	return 0;
}

Contributors
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Tokens
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CommitProp
Linus Torvalds (pre-git)
60
36.81%
1
10.00%
Fengguang Wu
58
35.58%
1
10.00%
Al Viro
18
11.04%
3
30.00%
Ingo Molnar
11
6.75%
1
10.00%
Andi Kleen
6
3.68%
1
10.00%
Andrew Morton
6
3.68%
1
10.00%
Kirill A. Shutemov
2
1.23%
1
10.00%
Dmitriy Monakhov
2
1.23%
1
10.00%
Total
163
100.00%
10
100.00%



struct dentry *ramfs_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	return mount_nodev(fs_type, flags, data, ramfs_fill_super);
}

Contributors
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Tokens
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CommitProp
Al Viro
30
83.33%
2
50.00%
Linus Torvalds (pre-git)
5
13.89%
1
25.00%
Andries E. Brouwer
1
2.78%
1
25.00%
Total
36
100.00%
4
100.00%



static void ramfs_kill_sb(struct super_block *sb)
{
	kfree(sb->s_fs_info);
	kill_litter_super(sb);
}

Contributors
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Fengguang Wu
23
100.00%
1
100.00%
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23
100.00%
1
100.00%


static struct file_system_type ramfs_fs_type = {
	.name		= "ramfs",
	.mount		= ramfs_mount,
	.kill_sb	= ramfs_kill_sb,
	.fs_flags	= FS_USERNS_MOUNT,
};



int __init init_ramfs_fs(void)
{
	static unsigned long once;

	if (test_and_set_bit(0, &once))
		return 0;
	return register_filesystem(&ramfs_fs_type);
}
Contributors
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Tokens
Prop
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CommitProp
Rob Landley
18
54.55%
1
50.00%
Linus Torvalds (pre-git)
15
45.45%
1
50.00%
Total
33
100.00%
2
100.00%


fs_initcall(init_ramfs_fs);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
457
42.59%
3
5.26%
Fengguang Wu
249
23.21%
1
1.75%
Al Viro
115
10.72%
14
24.56%
Andrew Morton
31
2.89%
6
10.53%
Art Haas
28
2.61%
1
1.75%
Axel Lin
28
2.61%
1
1.75%
Linus Torvalds
21
1.96%
6
10.53%
Rob Landley
18
1.68%
1
1.75%
Dmitriy Monakhov
18
1.68%
1
1.75%
Deepa Dinamani
12
1.12%
1
1.75%
Ingo Molnar
11
1.03%
1
1.75%
Mel Gorman
9
0.84%
1
1.75%
Peter Staubach
9
0.84%
1
1.75%
Hirofumi Ogawa
7
0.65%
1
1.75%
Christoph Hellwig
7
0.65%
1
1.75%
Lee Schermerhorn
7
0.65%
1
1.75%
Andi Kleen
6
0.56%
1
1.75%
Dave Hansen
6
0.56%
1
1.75%
Eric W. Biedermann
5
0.47%
1
1.75%
David Howells
3
0.28%
1
1.75%
Tejun Heo
3
0.28%
1
1.75%
Paul Gortmaker
3
0.28%
1
1.75%
Matt Mackall
3
0.28%
1
1.75%
Andries E. Brouwer
3
0.28%
2
3.51%
Maximilian Attems
3
0.28%
1
1.75%
Alexey Dobriyan
3
0.28%
1
1.75%
Arjan van de Ven
2
0.19%
1
1.75%
Kirill A. Shutemov
2
0.19%
1
1.75%
Josef 'Jeff' Sipek
2
0.19%
1
1.75%
Trond Myklebust
1
0.09%
1
1.75%
Mike Frysinger
1
0.09%
1
1.75%
Total
1073
100.00%
57
100.00%
Directory: fs/ramfs

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