Release 4.14 arch/s390/hypfs/inode.c

/*
 *    Hypervisor filesystem for Linux on s390.
 *
 *    Copyright IBM Corp. 2006, 2008
 *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
 *    License: GPL
 */


#define KMSG_COMPONENT "hypfs"

#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/time.h>
#include <linux/parser.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/uio.h>
#include <asm/ebcdic.h>
#include "hypfs.h"


#define HYPFS_MAGIC 0x687970	
/* ASCII 'hyp' */

#define TMP_SIZE 64		
/* size of temporary buffers */

static struct dentry *hypfs_create_update_file(struct dentry *dir);


struct hypfs_sb_info {
	
kuid_t uid;			/* uid used for files and dirs */
	
kgid_t gid;			/* gid used for files and dirs */
	
struct dentry *update_file;	/* file to trigger update */
	
time_t last_update;		/* last update time in secs since 1970 */
	
struct mutex lock;		/* lock to protect update process */
};


static const struct file_operations hypfs_file_ops;

static struct file_system_type hypfs_type;

static const struct super_operations hypfs_s_ops;

/* start of list of all dentries, which have to be deleted on update */

static struct dentry *hypfs_last_dentry;



static void hypfs_update_update(struct super_block *sb)
{
	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	struct inode *inode = d_inode(sb_info->update_file);

	sb_info->last_update = get_seconds();
	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
}

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Michael Holzheu
49
87.50%
1
33.33%
Deepa Dinamani
4
7.14%
1
33.33%
David Howells
3
5.36%
1
33.33%
Total
56
100.00%
3
100.00%

/* directory tree removal functions */



static void hypfs_add_dentry(struct dentry *dentry)
{
	dentry->d_fsdata = hypfs_last_dentry;
	hypfs_last_dentry = dentry;
}

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Michael Holzheu
21
100.00%
1
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21
100.00%
1
100.00%



static void hypfs_remove(struct dentry *dentry)
{
	struct dentry *parent;

	parent = dentry->d_parent;
	inode_lock(d_inode(parent));
	if (simple_positive(dentry)) {
		if (d_is_dir(dentry))
			simple_rmdir(d_inode(parent), dentry);
		else
			simple_unlink(d_inode(parent), dentry);
	}
	d_delete(dentry);
	dput(dentry);
	inode_unlock(d_inode(parent));
}

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Michael Holzheu
69
81.18%
2
33.33%
David Howells
13
15.29%
2
33.33%
Al Viro
3
3.53%
2
33.33%
Total
85
100.00%
6
100.00%



static void hypfs_delete_tree(struct dentry *root)
{
	while (hypfs_last_dentry) {
		struct dentry *next_dentry;
		next_dentry = hypfs_last_dentry->d_fsdata;
		hypfs_remove(hypfs_last_dentry);
		hypfs_last_dentry = next_dentry;
	}
}

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Michael Holzheu
37
100.00%
1
100.00%
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37
100.00%
1
100.00%



static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
{
	struct inode *ret = new_inode(sb);

	if (ret) {
		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
		ret->i_ino = get_next_ino();
		ret->i_mode = mode;
		ret->i_uid = hypfs_info->uid;
		ret->i_gid = hypfs_info->gid;
		ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
		if (S_ISDIR(mode))
			set_nlink(ret, 2);
	}
	return ret;
}

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Michael Holzheu
92
88.46%
2
40.00%
Miklos Szeredi
4
3.85%
1
20.00%
Al Viro
4
3.85%
1
20.00%
Deepa Dinamani
4
3.85%
1
20.00%
Total
104
100.00%
5
100.00%



static void hypfs_evict_inode(struct inode *inode)
{
	clear_inode(inode);
	kfree(inode->i_private);
}

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Michael Holzheu
18
78.26%
1
33.33%
Al Viro
4
17.39%
1
33.33%
Jan Kara
1
4.35%
1
33.33%
Total
23
100.00%
3
100.00%



static int hypfs_open(struct inode *inode, struct file *filp)
{
	char *data = file_inode(filp)->i_private;
	struct hypfs_sb_info *fs_info;

	if (filp->f_mode & FMODE_WRITE) {
		if (!(inode->i_mode & S_IWUGO))
			return -EACCES;
	}
	if (filp->f_mode & FMODE_READ) {
		if (!(inode->i_mode & S_IRUGO))
			return -EACCES;
	}

	fs_info = inode->i_sb->s_fs_info;
	if(data) {
		mutex_lock(&fs_info->lock);
		filp->private_data = kstrdup(data, GFP_KERNEL);
		if (!filp->private_data) {
			mutex_unlock(&fs_info->lock);
			return -ENOMEM;
		}
		mutex_unlock(&fs_info->lock);
	}
	return nonseekable_open(inode, filp);
}

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Michael Holzheu
142
93.42%
1
25.00%
Martin Schwidefsky
6
3.95%
1
25.00%
Al Viro
3
1.97%
1
25.00%
Theodore Y. Ts'o
1
0.66%
1
25.00%
Total
152
100.00%
4
100.00%



static ssize_t hypfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *file = iocb->ki_filp;
	char *data = file->private_data;
	size_t available = strlen(data);
	loff_t pos = iocb->ki_pos;
	size_t count;

	if (pos < 0)
		return -EINVAL;
	if (pos >= available || !iov_iter_count(to))
		return 0;
	count = copy_to_iter(data + pos, available - pos, to);
	if (!count)
		return -EFAULT;
	iocb->ki_pos = pos + count;
	file_accessed(file);
	return count;
}

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Al Viro
60
51.72%
1
25.00%
Michael Holzheu
36
31.03%
1
25.00%
Badari Pulavarty
13
11.21%
1
25.00%
Akinobu Mita
7
6.03%
1
25.00%
Total
116
100.00%
4
100.00%



static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	int rc;
	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
	struct hypfs_sb_info *fs_info = sb->s_fs_info;
	size_t count = iov_iter_count(from);

	/*
         * Currently we only allow one update per second for two reasons:
         * 1. diag 204 is VERY expensive
         * 2. If several processes do updates in parallel and then read the
         *    hypfs data, the likelihood of collisions is reduced, if we restrict
         *    the minimum update interval. A collision occurs, if during the
         *    data gathering of one process another process triggers an update
         *    If the first process wants to ensure consistent data, it has
         *    to restart data collection in this case.
         */
	mutex_lock(&fs_info->lock);
	if (fs_info->last_update == get_seconds()) {
		rc = -EBUSY;
		goto out;
	}
	hypfs_delete_tree(sb->s_root);
	if (MACHINE_IS_VM)
		rc = hypfs_vm_create_files(sb->s_root);
	else
		rc = hypfs_diag_create_files(sb->s_root);
	if (rc) {
		pr_err("Updating the hypfs tree failed\n");
		hypfs_delete_tree(sb->s_root);
		goto out;
	}
	hypfs_update_update(sb);
	rc = count;
	iov_iter_advance(from, count);
out:
	mutex_unlock(&fs_info->lock);
	return rc;
}

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Michael Holzheu
126
79.75%
3
50.00%
Al Viro
25
15.82%
2
33.33%
Badari Pulavarty
7
4.43%
1
16.67%
Total
158
100.00%
6
100.00%



static int hypfs_release(struct inode *inode, struct file *filp)
{
	kfree(filp->private_data);
	return 0;
}

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Michael Holzheu
26
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1
100.00%
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26
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1
100.00%




enum { opt_uid, opt_gid, opt_err };


static const match_table_t hypfs_tokens = {
	{opt_uid, "uid=%u"},
	{opt_gid, "gid=%u"},
	{opt_err, NULL}
};



static int hypfs_parse_options(char *options, struct super_block *sb)
{
	char *str;
	substring_t args[MAX_OPT_ARGS];
	kuid_t uid;
	kgid_t gid;

	if (!options)
		return 0;
	while ((str = strsep(&options, ",")) != NULL) {
		int token, option;
		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;

		if (!*str)
			continue;
		token = match_token(str, hypfs_tokens, args);
		switch (token) {
		case opt_uid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			uid = make_kuid(current_user_ns(), option);
			if (!uid_valid(uid))
				return -EINVAL;
			hypfs_info->uid = uid;
			break;
		case opt_gid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			gid = make_kgid(current_user_ns(), option);
			if (!gid_valid(gid))
				return -EINVAL;
			hypfs_info->gid = gid;
			break;
		case opt_err:
		default:
			pr_err("%s is not a valid mount option\n", str);
			return -EINVAL;
		}
	}
	return 0;
}

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Michael Holzheu
161
75.59%
2
66.67%
Eric W. Biedermann
52
24.41%
1
33.33%
Total
213
100.00%
3
100.00%



static int hypfs_show_options(struct seq_file *s, struct dentry *root)
{
	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;

	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
	return 0;
}

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Michael Holzheu
48
75.00%
1
33.33%
Eric W. Biedermann
12
18.75%
1
33.33%
Al Viro
4
6.25%
1
33.33%
Total
64
100.00%
3
100.00%



static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct inode *root_inode;
	struct dentry *root_dentry;
	int rc = 0;
	struct hypfs_sb_info *sbi;

	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;
	mutex_init(&sbi->lock);
	sbi->uid = current_uid();
	sbi->gid = current_gid();
	sb->s_fs_info = sbi;
	sb->s_blocksize = PAGE_SIZE;
	sb->s_blocksize_bits = PAGE_SHIFT;
	sb->s_magic = HYPFS_MAGIC;
	sb->s_op = &hypfs_s_ops;
	if (hypfs_parse_options(data, sb))
		return -EINVAL;
	root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
	if (!root_inode)
		return -ENOMEM;
	root_inode->i_op = &simple_dir_inode_operations;
	root_inode->i_fop = &simple_dir_operations;
	sb->s_root = root_dentry = d_make_root(root_inode);
	if (!root_dentry)
		return -ENOMEM;
	if (MACHINE_IS_VM)
		rc = hypfs_vm_create_files(root_dentry);
	else
		rc = hypfs_diag_create_files(root_dentry);
	if (rc)
		return rc;
	sbi->update_file = hypfs_create_update_file(root_dentry);
	if (IS_ERR(sbi->update_file))
		return PTR_ERR(sbi->update_file);
	hypfs_update_update(sb);
	pr_info("Hypervisor filesystem mounted\n");
	return 0;
}

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Michael Holzheu
223
91.02%
4
50.00%
Al Viro
16
6.53%
2
25.00%
David Howells
4
1.63%
1
12.50%
Kirill A. Shutemov
2
0.82%
1
12.50%
Total
245
100.00%
8
100.00%



static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
			const char *devname, void *data)
{
	return mount_single(fst, flags, data, hypfs_fill_super);
}

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Michael Holzheu
32
86.49%
1
50.00%
Al Viro
5
13.51%
1
50.00%
Total
37
100.00%
2
100.00%



static void hypfs_kill_super(struct super_block *sb)
{
	struct hypfs_sb_info *sb_info = sb->s_fs_info;

	if (sb->s_root)
		hypfs_delete_tree(sb->s_root);
	if (sb_info->update_file)
		hypfs_remove(sb_info->update_file);
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
	kill_litter_super(sb);
}

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Michael Holzheu
58
90.62%
2
66.67%
Al Viro
6
9.38%
1
33.33%
Total
64
100.00%
3
100.00%



static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
					char *data, umode_t mode)
{
	struct dentry *dentry;
	struct inode *inode;

	inode_lock(d_inode(parent));
	dentry = lookup_one_len(name, parent, strlen(name));
	if (IS_ERR(dentry)) {
		dentry = ERR_PTR(-ENOMEM);
		goto fail;
	}
	inode = hypfs_make_inode(parent->d_sb, mode);
	if (!inode) {
		dput(dentry);
		dentry = ERR_PTR(-ENOMEM);
		goto fail;
	}
	if (S_ISREG(mode)) {
		inode->i_fop = &hypfs_file_ops;
		if (data)
			inode->i_size = strlen(data);
		else
			inode->i_size = 0;
	} else if (S_ISDIR(mode)) {
		inode->i_op = &simple_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
		inc_nlink(d_inode(parent));
	} else
		BUG();
	inode->i_private = data;
	d_instantiate(dentry, inode);
	dget(dentry);
fail:
	inode_unlock(d_inode(parent));
	return dentry;
}

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Michael Holzheu
189
88.32%
2
25.00%
Al Viro
12
5.61%
3
37.50%
David Howells
9
4.21%
1
12.50%
Miklos Szeredi
3
1.40%
1
12.50%
Theodore Y. Ts'o
1
0.47%
1
12.50%
Total
214
100.00%
8
100.00%



struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
{
	struct dentry *dentry;

	dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
	if (IS_ERR(dentry))
		return dentry;
	hypfs_add_dentry(dentry);
	return dentry;
}

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Michael Holzheu
55
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1
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55
100.00%
1
100.00%



static struct dentry *hypfs_create_update_file(struct dentry *dir)
{
	struct dentry *dentry;

	dentry = hypfs_create_file(dir, "update", NULL,
				   S_IFREG | UPDATE_FILE_MODE);
	/*
         * We do not put the update file on the 'delete' list with
         * hypfs_add_dentry(), since it should not be removed when the tree
         * is updated.
         */
	return dentry;
}

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Michael Holzheu
37
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1
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37
100.00%
1
100.00%



struct dentry *hypfs_create_u64(struct dentry *dir,
				const char *name, __u64 value)
{
	char *buffer;
	char tmp[TMP_SIZE];
	struct dentry *dentry;

	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
	buffer = kstrdup(tmp, GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);
	dentry =
	    hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
	if (IS_ERR(dentry)) {
		kfree(buffer);
		return ERR_PTR(-ENOMEM);
	}
	hypfs_add_dentry(dentry);
	return dentry;
}

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Michael Holzheu
117
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2
100.00%
Total
117
100.00%
2
100.00%



struct dentry *hypfs_create_str(struct dentry *dir,
				const char *name, char *string)
{
	char *buffer;
	struct dentry *dentry;

	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);
	sprintf(buffer, "%s\n", string);
	dentry =
	    hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
	if (IS_ERR(dentry)) {
		kfree(buffer);
		return ERR_PTR(-ENOMEM);
	}
	hypfs_add_dentry(dentry);
	return dentry;
}

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109
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1
100.00%
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109
100.00%
1
100.00%


static const struct file_operations hypfs_file_ops = {
	.open		= hypfs_open,
	.release	= hypfs_release,
	.read_iter	= hypfs_read_iter,
	.write_iter	= hypfs_write_iter,
	.llseek		= no_llseek,
};


static struct file_system_type hypfs_type = {
	.owner		= THIS_MODULE,
	.name		= "s390_hypfs",
	.mount		= hypfs_mount,
	.kill_sb	= hypfs_kill_super
};


static const struct super_operations hypfs_s_ops = {
	.statfs		= simple_statfs,
	.evict_inode	= hypfs_evict_inode,
	.show_options	= hypfs_show_options,
};



static int __init hypfs_init(void)
{
	int rc;

	rc = hypfs_dbfs_init();
	if (rc)
		return rc;
	if (hypfs_diag_init()) {
		rc = -ENODATA;
		goto fail_dbfs_exit;
	}
	if (hypfs_vm_init()) {
		rc = -ENODATA;
		goto fail_hypfs_diag_exit;
	}
	if (hypfs_sprp_init()) {
		rc = -ENODATA;
		goto fail_hypfs_vm_exit;
	}
	if (hypfs_diag0c_init()) {
		rc = -ENODATA;
		goto fail_hypfs_sprp_exit;
	}
	rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
	if (rc)
		goto fail_hypfs_diag0c_exit;
	rc = register_filesystem(&hypfs_type);
	if (rc)
		goto fail_filesystem;
	return 0;

fail_filesystem:
	sysfs_remove_mount_point(hypervisor_kobj, "s390");
fail_hypfs_diag0c_exit:
	hypfs_diag0c_exit();
fail_hypfs_sprp_exit:
	hypfs_sprp_exit();
fail_hypfs_vm_exit:
	hypfs_vm_exit();
fail_hypfs_diag_exit:
	hypfs_diag_exit();
fail_dbfs_exit:
	hypfs_dbfs_exit();
	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
	return rc;
}
Contributors
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Michael Holzheu
130
80.25%
6
60.00%
Martin Schwidefsky
20
12.35%
1
10.00%
Eric W. Biedermann
9
5.56%
1
10.00%
Greg Kroah-Hartman
3
1.85%
2
20.00%
Total
162
100.00%
10
100.00%

device_initcall(hypfs_init)
Overall Contributors
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Michael Holzheu
2003
85.09%
11
22.92%
Al Viro
150
6.37%
12
25.00%
Eric W. Biedermann
75
3.19%
2
4.17%
David Howells
29
1.23%
3
6.25%
Martin Schwidefsky
26
1.10%
2
4.17%
Badari Pulavarty
20
0.85%
1
2.08%
Deepa Dinamani
8
0.34%
1
2.08%
Akinobu Mita
7
0.30%
1
2.08%
Miklos Szeredi
7
0.30%
2
4.17%
Paul Gortmaker
6
0.25%
1
2.08%
Arnd Bergmann
5
0.21%
1
2.08%
Greg Kroah-Hartman
3
0.13%
2
4.17%
Kirill A. Shutemov
2
0.08%
1
2.08%
Theodore Y. Ts'o
2
0.08%
1
2.08%
Arjan van de Ven
2
0.08%
1
2.08%
Tejun Heo
2
0.08%
1
2.08%
Kent Overstreet
2
0.08%
1
2.08%
Alexey Dobriyan
2
0.08%
1
2.08%
Steven Whitehouse
1
0.04%
1
2.08%
Jan Kara
1
0.04%
1
2.08%
Christoph Hellwig
1
0.04%
1
2.08%
Total
2354
100.00%
48
100.00%
Directory: arch/s390/hypfs

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