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 000000000000..bab560a1357a
--- /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");