| /* |
| * 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/module.h> |
| #include <linux/seq_file.h> |
| #include <linux/mount.h> |
| #include <linux/aio.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 super_block *sb, |
| 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 = 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 inline int hypfs_positive(struct dentry *dentry) |
| { |
| return dentry->d_inode && !d_unhashed(dentry); |
| } |
| |
| static void hypfs_remove(struct dentry *dentry) |
| { |
| struct dentry *parent; |
| |
| parent = dentry->d_parent; |
| mutex_lock(&parent->d_inode->i_mutex); |
| if (hypfs_positive(dentry)) { |
| 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); |
| mutex_unlock(&parent->d_inode->i_mutex); |
| } |
| |
| 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; |
| 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_aio_read(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t offset) |
| { |
| char *data; |
| ssize_t ret; |
| struct file *filp = iocb->ki_filp; |
| /* XXX: temporary */ |
| char __user *buf = iov[0].iov_base; |
| size_t count = iov[0].iov_len; |
| |
| if (nr_segs != 1) |
| return -EINVAL; |
| |
| data = filp->private_data; |
| ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data)); |
| if (ret <= 0) |
| return ret; |
| |
| iocb->ki_pos += ret; |
| file_accessed(filp); |
| |
| return ret; |
| } |
| static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t offset) |
| { |
| 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_length(iov, nr_segs); |
| |
| /* |
| * 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, sb->s_root); |
| else |
| rc = hypfs_diag_create_files(sb, 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; |
| 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_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)) |
| 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(sb, root_dentry); |
| else |
| rc = hypfs_diag_create_files(sb, root_dentry); |
| if (rc) |
| return rc; |
| sbi->update_file = hypfs_create_update_file(sb, 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->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 super_block *sb, |
| struct dentry *parent, const char *name, |
| char *data, umode_t mode) |
| { |
| struct dentry *dentry; |
| struct inode *inode; |
| |
| mutex_lock(&parent->d_inode->i_mutex); |
| dentry = lookup_one_len(name, parent, strlen(name)); |
| if (IS_ERR(dentry)) { |
| dentry = ERR_PTR(-ENOMEM); |
| goto fail; |
| } |
| inode = hypfs_make_inode(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(parent->d_inode); |
| } else |
| BUG(); |
| inode->i_private = data; |
| d_instantiate(dentry, inode); |
| dget(dentry); |
| fail: |
| mutex_unlock(&parent->d_inode->i_mutex); |
| 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); |
| 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, "%llu\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 const 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, |
| .llseek = no_llseek, |
| }; |
| |
| static struct file_system_type hypfs_type = { |
| .owner = THIS_MODULE, |
| .name = "s390_hypfs", |
| .mount = hypfs_mount, |
| .kill_sb = hypfs_kill_super |
| }; |
| MODULE_ALIAS_FS("s390_hypfs"); |
| |
| static const struct super_operations hypfs_s_ops = { |
| .statfs = simple_statfs, |
| .evict_inode = hypfs_evict_inode, |
| .show_options = hypfs_show_options, |
| }; |
| |
| static struct kobject *s390_kobj; |
| |
| 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; |
| } |
| s390_kobj = kobject_create_and_add("s390", hypervisor_kobj); |
| if (!s390_kobj) { |
| rc = -ENOMEM; |
| goto fail_hypfs_vm_exit; |
| } |
| rc = register_filesystem(&hypfs_type); |
| if (rc) |
| goto fail_filesystem; |
| return 0; |
| |
| fail_filesystem: |
| kobject_put(s390_kobj); |
| 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; |
| } |
| |
| static void __exit hypfs_exit(void) |
| { |
| hypfs_diag_exit(); |
| hypfs_vm_exit(); |
| hypfs_dbfs_exit(); |
| unregister_filesystem(&hypfs_type); |
| kobject_put(s390_kobj); |
| } |
| |
| module_init(hypfs_init) |
| module_exit(hypfs_exit) |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); |
| MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |