1 files changed, 492 insertions, 0 deletions

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
new file mode 100644
index 0000000..bab560a
--- /dev/null
+++ b/arch/s390/hypfs/inode.c
@@ -0,0 +1,492 @@
+/*
+ *  fs/hypfs/inode.c
+ *    Hypervisor filesystem for Linux on s390.
+ *
+ *    Copyright (C) IBM Corp. 2006
+ *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/vfs.h>
+#include <linux/pagemap.h>
+#include <linux/gfp.h>
+#include <linux/time.h>
+#include <linux/parser.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <asm/ebcdic.h>
+#include "hypfs.h"
+#include "hypfs_diag.h"
+
+#define HYPFS_MAGIC 0x687970	/* ASCII 'hyp' */
+#define TMP_SIZE 64		/* size of temporary buffers */
+
+static struct dentry *hypfs_create_update_file(struct super_block *sb,
+					       struct dentry *dir);
+
+struct hypfs_sb_info {
+	uid_t uid;			/* uid used for files and dirs */
+	gid_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 struct file_operations hypfs_file_ops;
+static struct file_system_type hypfs_type;
+static 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 = sb_info->update_file->d_inode;
+
+	sb_info->last_update = get_seconds();
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+}
+
+/* directory tree removal functions */
+
+static void hypfs_add_dentry(struct dentry *dentry)
+{
+	dentry->d_fsdata = hypfs_last_dentry;
+	hypfs_last_dentry = dentry;
+}
+
+static void hypfs_remove(struct dentry *dentry)
+{
+	struct dentry *parent;
+
+	parent = dentry->d_parent;
+	if (S_ISDIR(dentry->d_inode->i_mode))
+		simple_rmdir(parent->d_inode, dentry);
+	else
+		simple_unlink(parent->d_inode, dentry);
+	d_delete(dentry);
+	dput(dentry);
+}
+
+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;
+	}
+}
+
+static struct inode *hypfs_make_inode(struct super_block *sb, int mode)
+{
+	struct inode *ret = new_inode(sb);
+
+	if (ret) {
+		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
+		ret->i_mode = mode;
+		ret->i_uid = hypfs_info->uid;
+		ret->i_gid = hypfs_info->gid;
+		ret->i_blksize = PAGE_CACHE_SIZE;
+		ret->i_blocks = 0;
+		ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
+		if (mode & S_IFDIR)
+			ret->i_nlink = 2;
+		else
+			ret->i_nlink = 1;
+	}
+	return ret;
+}
+
+static void hypfs_drop_inode(struct inode *inode)
+{
+	kfree(inode->u.generic_ip);
+	generic_delete_inode(inode);
+}
+
+static int hypfs_open(struct inode *inode, struct file *filp)
+{
+	char *data = filp->f_dentry->d_inode->u.generic_ip;
+	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 0;
+}
+
+static ssize_t hypfs_aio_read(struct kiocb *iocb, __user char *buf,
+			      size_t count, loff_t offset)
+{
+	char *data;
+	size_t len;
+	struct file *filp = iocb->ki_filp;
+
+	data = filp->private_data;
+	len = strlen(data);
+	if (offset > len) {
+		count = 0;
+		goto out;
+	}
+	if (count > len - offset)
+		count = len - offset;
+	if (copy_to_user(buf, data + offset, count)) {
+		count = -EFAULT;
+		goto out;
+	}
+	iocb->ki_pos += count;
+	file_accessed(filp);
+out:
+	return count;
+}
+static ssize_t hypfs_aio_write(struct kiocb *iocb, const char __user *buf,
+			       size_t count, loff_t pos)
+{
+	int rc;
+	struct super_block *sb;
+	struct hypfs_sb_info *fs_info;
+
+	sb = iocb->ki_filp->f_dentry->d_inode->i_sb;
+	fs_info = sb->s_fs_info;
+	/*
+	 * 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);
+	rc = hypfs_diag_create_files(sb, sb->s_root);
+	if (rc) {
+		printk(KERN_ERR "hypfs: Update failed\n");
+		hypfs_delete_tree(sb->s_root);
+		goto out;
+	}
+	hypfs_update_update(sb);
+	rc = count;
+out:
+	mutex_unlock(&fs_info->lock);
+	return rc;
+}
+
+static int hypfs_release(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	return 0;
+}
+
+enum { opt_uid, opt_gid, opt_err };
+
+static 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];
+
+	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;
+			hypfs_info->uid = option;
+			break;
+		case opt_gid:
+			if (match_int(&args[0], &option))
+				return -EINVAL;
+			hypfs_info->gid = option;
+			break;
+		case opt_err:
+		default:
+			printk(KERN_ERR "hypfs: Unrecognized mount option "
+			       "\"%s\" or missing value\n", str);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+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_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_magic = HYPFS_MAGIC;
+	sb->s_op = &hypfs_s_ops;
+	if (hypfs_parse_options(data, sb)) {
+		rc = -EINVAL;
+		goto err_alloc;
+	}
+	root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
+	if (!root_inode) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	root_inode->i_op = &simple_dir_inode_operations;
+	root_inode->i_fop = &simple_dir_operations;
+	root_dentry = d_alloc_root(root_inode);
+	if (!root_dentry) {
+		iput(root_inode);
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	rc = hypfs_diag_create_files(sb, root_dentry);
+	if (rc)
+		goto err_tree;
+	sbi->update_file = hypfs_create_update_file(sb, root_dentry);
+	if (IS_ERR(sbi->update_file)) {
+		rc = PTR_ERR(sbi->update_file);
+		goto err_tree;
+	}
+	hypfs_update_update(sb);
+	sb->s_root = root_dentry;
+	return 0;
+
+err_tree:
+	hypfs_delete_tree(root_dentry);
+	d_genocide(root_dentry);
+	dput(root_dentry);
+err_alloc:
+	kfree(sbi);
+	return rc;
+}
+
+static struct super_block *hypfs_get_super(struct file_system_type *fst,
+					   int flags, const char *devname,
+					   void *data)
+{
+	return get_sb_single(fst, flags, data, hypfs_fill_super);
+}
+
+static void hypfs_kill_super(struct super_block *sb)
+{
+	struct hypfs_sb_info *sb_info = sb->s_fs_info;
+
+	hypfs_delete_tree(sb->s_root);
+	hypfs_remove(sb_info->update_file);
+	kfree(sb->s_fs_info);
+	sb->s_fs_info = NULL;
+	kill_litter_super(sb);
+}
+
+static struct dentry *hypfs_create_file(struct super_block *sb,
+					struct dentry *parent, const char *name,
+					char *data, mode_t mode)
+{
+	struct dentry *dentry;
+	struct inode *inode;
+	struct qstr qname;
+
+	qname.name = name;
+	qname.len = strlen(name);
+	qname.hash = full_name_hash(name, qname.len);
+	dentry = lookup_one_len(name, parent, strlen(name));
+	if (IS_ERR(dentry))
+		return ERR_PTR(-ENOMEM);
+	inode = hypfs_make_inode(sb, mode);
+	if (!inode) {
+		dput(dentry);
+		return ERR_PTR(-ENOMEM);
+	}
+	if (mode & S_IFREG) {
+		inode->i_fop = &hypfs_file_ops;
+		if (data)
+			inode->i_size = strlen(data);
+		else
+			inode->i_size = 0;
+	} else if (mode & S_IFDIR) {
+		inode->i_op = &simple_dir_inode_operations;
+		inode->i_fop = &simple_dir_operations;
+		parent->d_inode->i_nlink++;
+	} else
+		BUG();
+	inode->u.generic_ip = data;
+	d_instantiate(dentry, inode);
+	dget(dentry);
+	return dentry;
+}
+
+struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent,
+			   const char *name)
+{
+	struct dentry *dentry;
+
+	dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE);
+	if (IS_ERR(dentry))
+		return dentry;
+	hypfs_add_dentry(dentry);
+	parent->d_inode->i_nlink++;
+	return dentry;
+}
+
+static struct dentry *hypfs_create_update_file(struct super_block *sb,
+					       struct dentry *dir)
+{
+	struct dentry *dentry;
+
+	dentry = hypfs_create_file(sb, 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;
+}
+
+struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir,
+				const char *name, __u64 value)
+{
+	char *buffer;
+	char tmp[TMP_SIZE];
+	struct dentry *dentry;
+
+	snprintf(tmp, TMP_SIZE, "%lld\n", (unsigned long long int)value);
+	buffer = kstrdup(tmp, GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+	dentry =
+	    hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
+	if (IS_ERR(dentry)) {
+		kfree(buffer);
+		return ERR_PTR(-ENOMEM);
+	}
+	hypfs_add_dentry(dentry);
+	return dentry;
+}
+
+struct dentry *hypfs_create_str(struct super_block *sb, 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(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE);
+	if (IS_ERR(dentry)) {
+		kfree(buffer);
+		return ERR_PTR(-ENOMEM);
+	}
+	hypfs_add_dentry(dentry);
+	return dentry;
+}
+
+static struct file_operations hypfs_file_ops = {
+	.open		= hypfs_open,
+	.release	= hypfs_release,
+	.read		= do_sync_read,
+	.write		= do_sync_write,
+	.aio_read	= hypfs_aio_read,
+	.aio_write	= hypfs_aio_write,
+};
+
+static struct file_system_type hypfs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "s390_hypfs",
+	.get_sb		= hypfs_get_super,
+	.kill_sb	= hypfs_kill_super
+};
+
+static struct super_operations hypfs_s_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode	= hypfs_drop_inode,
+};
+
+static decl_subsys(s390, NULL, NULL);
+
+static int __init hypfs_init(void)
+{
+	int rc;
+
+	if (MACHINE_IS_VM)
+		return -ENODATA;
+	if (hypfs_diag_init()) {
+		rc = -ENODATA;
+		goto fail_diag;
+	}
+	kset_set_kset_s(&s390_subsys, hypervisor_subsys);
+	rc = subsystem_register(&s390_subsys);
+	if (rc)
+		goto fail_sysfs;
+	rc = register_filesystem(&hypfs_type);
+	if (rc)
+		goto fail_filesystem;
+	return 0;
+
+fail_filesystem:
+	subsystem_unregister(&s390_subsys);
+fail_sysfs:
+	hypfs_diag_exit();
+fail_diag:
+	printk(KERN_ERR "hypfs: Initialization failed with rc = %i.\n", rc);
+	return rc;
+}
+
+static void __exit hypfs_exit(void)
+{
+	hypfs_diag_exit();
+	unregister_filesystem(&hypfs_type);
+	subsystem_unregister(&s390_subsys);
+}
+
+module_init(hypfs_init)
+module_exit(hypfs_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
+MODULE_DESCRIPTION("s390 Hypervisor Filesystem");