v4.19.13 snapshot.
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
new file mode 100644
index 0000000..c681329
--- /dev/null
+++ b/arch/s390/hypfs/inode.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * Hypervisor filesystem for Linux on s390.
+ *
+ * Copyright IBM Corp. 2006, 2008
+ * Author(s): Michael Holzheu <holzheu@de.ibm.com>
+ */
+
+#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 */
+ time64_t last_update; /* last update, CLOCK_MONOTONIC time */
+ 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 = ktime_get_seconds();
+ inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+}
+
+/* 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;
+ 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));
+}
+
+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, 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;
+}
+
+static void hypfs_evict_inode(struct inode *inode)
+{
+ clear_inode(inode);
+ kfree(inode->i_private);
+}
+
+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);
+}
+
+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;
+}
+
+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 == ktime_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;
+}
+
+static int hypfs_release(struct inode *inode, struct file *filp)
+{
+ kfree(filp->private_data);
+ return 0;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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);
+}
+
+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 && sb_info->update_file)
+ 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 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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+device_initcall(hypfs_init)