diff options
Diffstat (limited to 'fs/hppfs/hppfs.c')
| -rw-r--r-- | fs/hppfs/hppfs.c | 771 |
1 files changed, 771 insertions, 0 deletions
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c new file mode 100644 index 0000000..65077aa --- /dev/null +++ b/fs/hppfs/hppfs.c @@ -0,0 +1,771 @@ +/* + * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <linux/ctype.h> +#include <linux/dcache.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/slab.h> +#include <linux/statfs.h> +#include <linux/types.h> +#include <asm/uaccess.h> +#include "os.h" + +static struct inode *get_inode(struct super_block *, struct dentry *); + +struct hppfs_data { + struct list_head list; + char contents[PAGE_SIZE - sizeof(struct list_head)]; +}; + +struct hppfs_private { + struct file *proc_file; + int host_fd; + loff_t len; + struct hppfs_data *contents; +}; + +struct hppfs_inode_info { + struct dentry *proc_dentry; + struct inode vfs_inode; +}; + +static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode) +{ + return container_of(inode, struct hppfs_inode_info, vfs_inode); +} + +#define HPPFS_SUPER_MAGIC 0xb00000ee + +static const struct super_operations hppfs_sbops; + +static int is_pid(struct dentry *dentry) +{ + struct super_block *sb; + int i; + + sb = dentry->d_sb; + if (dentry->d_parent != sb->s_root) + return 0; + + for (i = 0; i < dentry->d_name.len; i++) { + if (!isdigit(dentry->d_name.name[i])) + return 0; + } + return 1; +} + +static char *dentry_name(struct dentry *dentry, int extra) +{ + struct dentry *parent; + char *root, *name; + const char *seg_name; + int len, seg_len; + + len = 0; + parent = dentry; + while (parent->d_parent != parent) { + if (is_pid(parent)) + len += strlen("pid") + 1; + else len += parent->d_name.len + 1; + parent = parent->d_parent; + } + + root = "proc"; + len += strlen(root); + name = kmalloc(len + extra + 1, GFP_KERNEL); + if (name == NULL) + return NULL; + + name[len] = '\0'; + parent = dentry; + while (parent->d_parent != parent) { + if (is_pid(parent)) { + seg_name = "pid"; + seg_len = strlen("pid"); + } + else { + seg_name = parent->d_name.name; + seg_len = parent->d_name.len; + } + + len -= seg_len + 1; + name[len] = '/'; + strncpy(&name[len + 1], seg_name, seg_len); + parent = parent->d_parent; + } + strncpy(name, root, strlen(root)); + return name; +} + +static int file_removed(struct dentry *dentry, const char *file) +{ + char *host_file; + int extra, fd; + + extra = 0; + if (file != NULL) + extra += strlen(file) + 1; + + host_file = dentry_name(dentry, extra + strlen("/remove")); + if (host_file == NULL) { + printk(KERN_ERR "file_removed : allocation failed\n"); + return -ENOMEM; + } + + if (file != NULL) { + strcat(host_file, "/"); + strcat(host_file, file); + } + strcat(host_file, "/remove"); + + fd = os_open_file(host_file, of_read(OPENFLAGS()), 0); + kfree(host_file); + if (fd > 0) { + os_close_file(fd); + return 1; + } + return 0; +} + +static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry, + struct nameidata *nd) +{ + struct dentry *proc_dentry, *new, *parent; + struct inode *inode; + int err, deleted; + + deleted = file_removed(dentry, NULL); + if (deleted < 0) + return ERR_PTR(deleted); + else if (deleted) + return ERR_PTR(-ENOENT); + + err = -ENOMEM; + parent = HPPFS_I(ino)->proc_dentry; + mutex_lock(&parent->d_inode->i_mutex); + proc_dentry = d_lookup(parent, &dentry->d_name); + if (proc_dentry == NULL) { + proc_dentry = d_alloc(parent, &dentry->d_name); + if (proc_dentry == NULL) { + mutex_unlock(&parent->d_inode->i_mutex); + goto out; + } + new = (*parent->d_inode->i_op->lookup)(parent->d_inode, + proc_dentry, NULL); + if (new) { + dput(proc_dentry); + proc_dentry = new; + } + } + mutex_unlock(&parent->d_inode->i_mutex); + + if (IS_ERR(proc_dentry)) + return proc_dentry; + + err = -ENOMEM; + inode = get_inode(ino->i_sb, proc_dentry); + if (!inode) + goto out_dput; + + d_add(dentry, inode); + return NULL; + + out_dput: + dput(proc_dentry); + out: + return ERR_PTR(err); +} + +static const struct inode_operations hppfs_file_iops = { +}; + +static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count, + loff_t *ppos, int is_user) +{ + ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); + ssize_t n; + + read = file->f_path.dentry->d_inode->i_fop->read; + + if (!is_user) + set_fs(KERNEL_DS); + + n = (*read)(file, buf, count, &file->f_pos); + + if (!is_user) + set_fs(USER_DS); + + if (ppos) + *ppos = file->f_pos; + return n; +} + +static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count) +{ + ssize_t n; + int cur, err; + char *new_buf; + + n = -ENOMEM; + new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (new_buf == NULL) { + printk(KERN_ERR "hppfs_read_file : kmalloc failed\n"); + goto out; + } + n = 0; + while (count > 0) { + cur = min_t(ssize_t, count, PAGE_SIZE); + err = os_read_file(fd, new_buf, cur); + if (err < 0) { + printk(KERN_ERR "hppfs_read : read failed, " + "errno = %d\n", err); + n = err; + goto out_free; + } else if (err == 0) + break; + + if (copy_to_user(buf, new_buf, err)) { + n = -EFAULT; + goto out_free; + } + n += err; + count -= err; + } + out_free: + kfree(new_buf); + out: + return n; +} + +static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + struct hppfs_private *hppfs = file->private_data; + struct hppfs_data *data; + loff_t off; + int err; + + if (hppfs->contents != NULL) { + int rem; + + if (*ppos >= hppfs->len) + return 0; + + data = hppfs->contents; + off = *ppos; + while (off >= sizeof(data->contents)) { + data = list_entry(data->list.next, struct hppfs_data, + list); + off -= sizeof(data->contents); + } + + if (off + count > hppfs->len) + count = hppfs->len - off; + rem = copy_to_user(buf, &data->contents[off], count); + *ppos += count - rem; + if (rem > 0) + return -EFAULT; + } else if (hppfs->host_fd != -1) { + err = os_seek_file(hppfs->host_fd, *ppos); + if (err) { + printk(KERN_ERR "hppfs_read : seek failed, " + "errno = %d\n", err); + return err; + } + count = hppfs_read_file(hppfs->host_fd, buf, count); + if (count > 0) + *ppos += count; + } + else count = read_proc(hppfs->proc_file, buf, count, ppos, 1); + + return count; +} + +static ssize_t hppfs_write(struct file *file, const char __user *buf, + size_t len, loff_t *ppos) +{ + struct hppfs_private *data = file->private_data; + struct file *proc_file = data->proc_file; + ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); + + write = proc_file->f_path.dentry->d_inode->i_fop->write; + return (*write)(proc_file, buf, len, ppos); +} + +static int open_host_sock(char *host_file, int *filter_out) +{ + char *end; + int fd; + + end = &host_file[strlen(host_file)]; + strcpy(end, "/rw"); + *filter_out = 1; + fd = os_connect_socket(host_file); + if (fd > 0) + return fd; + + strcpy(end, "/r"); + *filter_out = 0; + fd = os_connect_socket(host_file); + return fd; +} + +static void free_contents(struct hppfs_data *head) +{ + struct hppfs_data *data; + struct list_head *ele, *next; + + if (head == NULL) + return; + + list_for_each_safe(ele, next, &head->list) { + data = list_entry(ele, struct hppfs_data, list); + kfree(data); + } + kfree(head); +} + +static struct hppfs_data *hppfs_get_data(int fd, int filter, + struct file *proc_file, + struct file *hppfs_file, + loff_t *size_out) +{ + struct hppfs_data *data, *new, *head; + int n, err; + + err = -ENOMEM; + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (data == NULL) { + printk(KERN_ERR "hppfs_get_data : head allocation failed\n"); + goto failed; + } + + INIT_LIST_HEAD(&data->list); + + head = data; + *size_out = 0; + + if (filter) { + while ((n = read_proc(proc_file, data->contents, + sizeof(data->contents), NULL, 0)) > 0) + os_write_file(fd, data->contents, n); + err = os_shutdown_socket(fd, 0, 1); + if (err) { + printk(KERN_ERR "hppfs_get_data : failed to shut down " + "socket\n"); + goto failed_free; + } + } + while (1) { + n = os_read_file(fd, data->contents, sizeof(data->contents)); + if (n < 0) { + err = n; + printk(KERN_ERR "hppfs_get_data : read failed, " + "errno = %d\n", err); + goto failed_free; + } else if (n == 0) + break; + + *size_out += n; + + if (n < sizeof(data->contents)) + break; + + new = kmalloc(sizeof(*data), GFP_KERNEL); + if (new == 0) { + printk(KERN_ERR "hppfs_get_data : data allocation " + "failed\n"); + err = -ENOMEM; + goto failed_free; + } + + INIT_LIST_HEAD(&new->list); + list_add(&new->list, &data->list); + data = new; + } + return head; + + failed_free: + free_contents(head); + failed: + return ERR_PTR(err); +} + +static struct hppfs_private *hppfs_data(void) +{ + struct hppfs_private *data; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (data == NULL) + return data; + + *data = ((struct hppfs_private ) { .host_fd = -1, + .len = -1, + .contents = NULL } ); + return data; +} + +static int file_mode(int fmode) +{ + if (fmode == (FMODE_READ | FMODE_WRITE)) + return O_RDWR; + if (fmode == FMODE_READ) + return O_RDONLY; + if (fmode == FMODE_WRITE) + return O_WRONLY; + return 0; +} + +static int hppfs_open(struct inode *inode, struct file *file) +{ + struct hppfs_private *data; + struct vfsmount *proc_mnt; + struct dentry *proc_dentry; + char *host_file; + int err, fd, type, filter; + + err = -ENOMEM; + data = hppfs_data(); + if (data == NULL) + goto out; + + host_file = dentry_name(file->f_path.dentry, strlen("/rw")); + if (host_file == NULL) + goto out_free2; + + proc_dentry = HPPFS_I(inode)->proc_dentry; + proc_mnt = inode->i_sb->s_fs_info; + + /* XXX This isn't closed anywhere */ + data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), + file_mode(file->f_mode)); + err = PTR_ERR(data->proc_file); + if (IS_ERR(data->proc_file)) + goto out_free1; + + type = os_file_type(host_file); + if (type == OS_TYPE_FILE) { + fd = os_open_file(host_file, of_read(OPENFLAGS()), 0); + if (fd >= 0) + data->host_fd = fd; + else + printk(KERN_ERR "hppfs_open : failed to open '%s', " + "errno = %d\n", host_file, -fd); + + data->contents = NULL; + } else if (type == OS_TYPE_DIR) { + fd = open_host_sock(host_file, &filter); + if (fd > 0) { + data->contents = hppfs_get_data(fd, filter, + data->proc_file, + file, &data->len); + if (!IS_ERR(data->contents)) + data->host_fd = fd; + } else + printk(KERN_ERR "hppfs_open : failed to open a socket " + "in '%s', errno = %d\n", host_file, -fd); + } + kfree(host_file); + + file->private_data = data; + return 0; + + out_free1: + kfree(host_file); + out_free2: + free_contents(data->contents); + kfree(data); + out: + return err; +} + +static int hppfs_dir_open(struct inode *inode, struct file *file) +{ + struct hppfs_private *data; + struct vfsmount *proc_mnt; + struct dentry *proc_dentry; + int err; + + err = -ENOMEM; + data = hppfs_data(); + if (data == NULL) + goto out; + + proc_dentry = HPPFS_I(inode)->proc_dentry; + proc_mnt = inode->i_sb->s_fs_info; + data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), + file_mode(file->f_mode)); + err = PTR_ERR(data->proc_file); + if (IS_ERR(data->proc_file)) + goto out_free; + + file->private_data = data; + return 0; + + out_free: + kfree(data); + out: + return err; +} + +static loff_t hppfs_llseek(struct file *file, loff_t off, int where) +{ + struct hppfs_private *data = file->private_data; + struct file *proc_file = data->proc_file; + loff_t (*llseek)(struct file *, loff_t, int); + loff_t ret; + + llseek = proc_file->f_path.dentry->d_inode->i_fop->llseek; + if (llseek != NULL) { + ret = (*llseek)(proc_file, off, where); + if (ret < 0) + return ret; + } + + return default_llseek(file, off, where); +} + +static const struct file_operations hppfs_file_fops = { + .owner = NULL, + .llseek = hppfs_llseek, + .read = hppfs_read, + .write = hppfs_write, + .open = hppfs_open, +}; + +struct hppfs_dirent { + void *vfs_dirent; + filldir_t filldir; + struct dentry *dentry; +}; + +static int hppfs_filldir(void *d, const char *name, int size, + loff_t offset, u64 inode, unsigned int type) +{ + struct hppfs_dirent *dirent = d; + + if (file_removed(dirent->dentry, name)) + return 0; + + return (*dirent->filldir)(dirent->vfs_dirent, name, size, offset, + inode, type); +} + +static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir) +{ + struct hppfs_private *data = file->private_data; + struct file *proc_file = data->proc_file; + int (*readdir)(struct file *, void *, filldir_t); + struct hppfs_dirent dirent = ((struct hppfs_dirent) + { .vfs_dirent = ent, + .filldir = filldir, + .dentry = file->f_path.dentry + }); + int err; + + readdir = proc_file->f_path.dentry->d_inode->i_fop->readdir; + + proc_file->f_pos = file->f_pos; + err = (*readdir)(proc_file, &dirent, hppfs_filldir); + file->f_pos = proc_file->f_pos; + + return err; +} + +static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + return 0; +} + +static const struct file_operations hppfs_dir_fops = { + .owner = NULL, + .readdir = hppfs_readdir, + .open = hppfs_dir_open, + .fsync = hppfs_fsync, +}; + +static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf) +{ + sf->f_blocks = 0; + sf->f_bfree = 0; + sf->f_bavail = 0; + sf->f_files = 0; + sf->f_ffree = 0; + sf->f_type = HPPFS_SUPER_MAGIC; + return 0; +} + +static struct inode *hppfs_alloc_inode(struct super_block *sb) +{ + struct hppfs_inode_info *hi; + + hi = kmalloc(sizeof(*hi), GFP_KERNEL); + if (!hi) + return NULL; + + hi->proc_dentry = NULL; + inode_init_once(&hi->vfs_inode); + return &hi->vfs_inode; +} + +void hppfs_delete_inode(struct inode *ino) +{ + dput(HPPFS_I(ino)->proc_dentry); + mntput(ino->i_sb->s_fs_info); + + clear_inode(ino); +} + +static void hppfs_destroy_inode(struct inode *inode) +{ + kfree(HPPFS_I(inode)); +} + +static const struct super_operations hppfs_sbops = { + .alloc_inode = hppfs_alloc_inode, + .destroy_inode = hppfs_destroy_inode, + .delete_inode = hppfs_delete_inode, + .statfs = hppfs_statfs, +}; + +static int hppfs_readlink(struct dentry *dentry, char __user *buffer, + int buflen) +{ + struct dentry *proc_dentry; + + proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; + return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, + buflen); +} + +static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct dentry *proc_dentry; + + proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; + + return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd); +} + +int hppfs_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + return generic_permission(inode, mask, NULL); +} + +static const struct inode_operations hppfs_dir_iops = { + .lookup = hppfs_lookup, + .permission = hppfs_permission, +}; + +static const struct inode_operations hppfs_link_iops = { + .readlink = hppfs_readlink, + .follow_link = hppfs_follow_link, + .permission = hppfs_permission, +}; + +static struct inode *get_inode(struct super_block *sb, struct dentry *dentry) +{ + struct inode *proc_ino = dentry->d_inode; + struct inode *inode = new_inode(sb); + + if (!inode) + return ERR_PTR(-ENOMEM); + + if (S_ISDIR(dentry->d_inode->i_mode)) { + inode->i_op = &hppfs_dir_iops; + inode->i_fop = &hppfs_dir_fops; + } else if (S_ISLNK(dentry->d_inode->i_mode)) { + inode->i_op = &hppfs_link_iops; + inode->i_fop = &hppfs_file_fops; + } else { + inode->i_op = &hppfs_file_iops; + inode->i_fop = &hppfs_file_fops; + } + + HPPFS_I(inode)->proc_dentry = dget(dentry); + + inode->i_uid = proc_ino->i_uid; + inode->i_gid = proc_ino->i_gid; + inode->i_atime = proc_ino->i_atime; + inode->i_mtime = proc_ino->i_mtime; + inode->i_ctime = proc_ino->i_ctime; + inode->i_ino = proc_ino->i_ino; + inode->i_mode = proc_ino->i_mode; + inode->i_nlink = proc_ino->i_nlink; + inode->i_size = proc_ino->i_size; + inode->i_blocks = proc_ino->i_blocks; + + return inode; +} + +static int hppfs_fill_super(struct super_block *sb, void *d, int silent) +{ + struct inode *root_inode; + struct vfsmount *proc_mnt; + int err = -ENOENT; + + proc_mnt = do_kern_mount("proc", 0, "proc", NULL); + if (IS_ERR(proc_mnt)) + goto out; + + sb->s_blocksize = 1024; + sb->s_blocksize_bits = 10; + sb->s_magic = HPPFS_SUPER_MAGIC; + sb->s_op = &hppfs_sbops; + sb->s_fs_info = proc_mnt; + + err = -ENOMEM; + root_inode = get_inode(sb, proc_mnt->mnt_sb->s_root); + if (!root_inode) + goto out_mntput; + + sb->s_root = d_alloc_root(root_inode); + if (!sb->s_root) + goto out_iput; + + return 0; + + out_iput: + iput(root_inode); + out_mntput: + mntput(proc_mnt); + out: + return(err); +} + +static int hppfs_read_super(struct file_system_type *type, + int flags, const char *dev_name, + void *data, struct vfsmount *mnt) +{ + return get_sb_nodev(type, flags, data, hppfs_fill_super, mnt); +} + +static struct file_system_type hppfs_type = { + .owner = THIS_MODULE, + .name = "hppfs", + .get_sb = hppfs_read_super, + .kill_sb = kill_anon_super, + .fs_flags = 0, +}; + +static int __init init_hppfs(void) +{ + return register_filesystem(&hppfs_type); +} + +static void __exit exit_hppfs(void) +{ + unregister_filesystem(&hppfs_type); +} + +module_init(init_hppfs) +module_exit(exit_hppfs) +MODULE_LICENSE("GPL"); |
