--- /dev/null
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ *
+ * Ported the filesystem routines to 2.5.
+ * 2003-02-10 Petr Baudis <pasky@ucw.cz>
+ */
+
+#include <linux/stddef.h>
+#include <linux/fs.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
+#include <linux/list.h>
+#include <linux/buffer_head.h>
+#include <linux/root_dev.h>
+#include <linux/statfs.h>
+#include <asm/uaccess.h>
+#include "hostfs.h"
+#include "kern_util.h"
+#include "kern.h"
+#include "user_util.h"
+#include "2_5compat.h"
+#include "init.h"
+
+struct hostfs_inode_info {
+ char *host_filename;
+ int fd;
+ int mode;
+ struct inode vfs_inode;
+};
+
+static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
+{
+ return(list_entry(inode, struct hostfs_inode_info, vfs_inode));
+}
+
+#define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_dentry->d_inode)
+
+int hostfs_d_delete(struct dentry *dentry)
+{
+ return(1);
+}
+
+struct dentry_operations hostfs_dentry_ops = {
+ .d_delete = hostfs_d_delete,
+};
+
+/* Changed in hostfs_args before the kernel starts running */
+static char *root_ino = "/";
+static int append = 0;
+
+#define HOSTFS_SUPER_MAGIC 0x00c0ffee
+
+static struct inode_operations hostfs_iops;
+static struct inode_operations hostfs_dir_iops;
+static struct address_space_operations hostfs_link_aops;
+
+static int __init hostfs_args(char *options, int *add)
+{
+ char *ptr;
+
+ ptr = strchr(options, ',');
+ if(ptr != NULL)
+ *ptr++ = '\0';
+ if(*options != '\0')
+ root_ino = options;
+
+ options = ptr;
+ while(options){
+ ptr = strchr(options, ',');
+ if(ptr != NULL)
+ *ptr++ = '\0';
+ if(*options != '\0'){
+ if(!strcmp(options, "append"))
+ append = 1;
+ else printf("hostfs_args - unsupported option - %s\n",
+ options);
+ }
+ options = ptr;
+ }
+ return(0);
+}
+
+__uml_setup("hostfs=", hostfs_args,
+"hostfs=<root dir>,<flags>,...\n"
+" This is used to set hostfs parameters. The root directory argument\n"
+" is used to confine all hostfs mounts to within the specified directory\n"
+" tree on the host. If this isn't specified, then a user inside UML can\n"
+" mount anything on the host that's accessible to the user that's running\n"
+" it.\n"
+" The only flag currently supported is 'append', which specifies that all\n"
+" files opened by hostfs will be opened in append mode.\n\n"
+);
+
+static char *dentry_name(struct dentry *dentry, int extra)
+{
+ struct dentry *parent;
+ char *root, *name;
+ int len;
+
+ len = 0;
+ parent = dentry;
+ while(parent->d_parent != parent){
+ len += parent->d_name.len + 1;
+ parent = parent->d_parent;
+ }
+
+ root = HOSTFS_I(parent->d_inode)->host_filename;
+ 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){
+ len -= parent->d_name.len + 1;
+ name[len] = '/';
+ strncpy(&name[len + 1], parent->d_name.name,
+ parent->d_name.len);
+ parent = parent->d_parent;
+ }
+ strncpy(name, root, strlen(root));
+ return(name);
+}
+
+static char *inode_name(struct inode *ino, int extra)
+{
+ struct dentry *dentry;
+
+ dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias);
+ return(dentry_name(dentry, extra));
+}
+
+static int read_name(struct inode *ino, char *name)
+{
+ /* The non-int inode fields are copied into ints by stat_file and
+ * then copied into the inode because passing the actual pointers
+ * in and having them treated as int * breaks on big-endian machines
+ */
+ int err;
+ int i_mode, i_nlink, i_blksize;
+ unsigned long long i_size;
+ unsigned long long i_ino;
+ unsigned long long i_blocks;
+
+ err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid,
+ &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime,
+ &ino->i_ctime, &i_blksize, &i_blocks);
+ if(err)
+ return(err);
+
+ ino->i_ino = i_ino;
+ ino->i_mode = i_mode;
+ ino->i_nlink = i_nlink;
+ ino->i_size = i_size;
+ ino->i_blksize = i_blksize;
+ ino->i_blocks = i_blocks;
+ if((ino->i_sb->s_dev == ROOT_DEV) && (ino->i_uid == getuid()))
+ ino->i_uid = 0;
+ return(0);
+}
+
+static char *follow_link(char *link)
+{
+ int len, n;
+ char *name, *resolved, *end;
+
+ len = 64;
+ while(1){
+ n = -ENOMEM;
+ name = kmalloc(len, GFP_KERNEL);
+ if(name == NULL)
+ goto out;
+
+ n = do_readlink(link, name, len);
+ if(n < len)
+ break;
+ len *= 2;
+ kfree(name);
+ }
+ if(n < 0)
+ goto out_free;
+
+ if(*name == '/')
+ return(name);
+
+ end = strrchr(link, '/');
+ if(end == NULL)
+ return(name);
+
+ *(end + 1) = '\0';
+ len = strlen(link) + strlen(name) + 1;
+
+ resolved = kmalloc(len, GFP_KERNEL);
+ if(resolved == NULL){
+ n = -ENOMEM;
+ goto out_free;
+ }
+
+ sprintf(resolved, "%s%s", link, name);
+ kfree(name);
+ kfree(link);
+ return(resolved);
+
+ out_free:
+ kfree(name);
+ out:
+ return(ERR_PTR(n));
+}
+
+static int read_inode(struct inode *ino)
+{
+ char *name;
+ int err = 0;
+
+ /* Unfortunately, we are called from iget() when we don't have a dentry
+ * allocated yet.
+ */
+ if(list_empty(&ino->i_dentry))
+ goto out;
+
+ err = -ENOMEM;
+ name = inode_name(ino, 0);
+ if(name == NULL)
+ goto out;
+
+ if(file_type(name, NULL) == OS_TYPE_SYMLINK){
+ name = follow_link(name);
+ if(IS_ERR(name)){
+ err = PTR_ERR(name);
+ goto out;
+ }
+ }
+
+ err = read_name(ino, name);
+ kfree(name);
+ out:
+ return(err);
+}
+
+int hostfs_statfs(struct super_block *sb, struct kstatfs *sf)
+{
+ /* do_statfs uses struct statfs64 internally, but the linux kernel
+ * struct statfs still has 32-bit versions for most of these fields,
+ * so we convert them here
+ */
+ int err;
+ long long f_blocks;
+ long long f_bfree;
+ long long f_bavail;
+ long long f_files;
+ long long f_ffree;
+
+ err = do_statfs(HOSTFS_I(sb->s_root->d_inode)->host_filename,
+ &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
+ &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
+ &sf->f_namelen, sf->f_spare);
+ if(err) return(err);
+ sf->f_blocks = f_blocks;
+ sf->f_bfree = f_bfree;
+ sf->f_bavail = f_bavail;
+ sf->f_files = f_files;
+ sf->f_ffree = f_ffree;
+ sf->f_type = HOSTFS_SUPER_MAGIC;
+ return(0);
+}
+
+static struct inode *hostfs_alloc_inode(struct super_block *sb)
+{
+ struct hostfs_inode_info *hi;
+
+ hi = kmalloc(sizeof(*hi), GFP_KERNEL);
+ if(hi == NULL)
+ return(NULL);
+
+ *hi = ((struct hostfs_inode_info) { .host_filename = NULL,
+ .fd = -1,
+ .mode = 0 });
+ inode_init_once(&hi->vfs_inode);
+ return(&hi->vfs_inode);
+}
+
+static void hostfs_destroy_inode(struct inode *inode)
+{
+ if(HOSTFS_I(inode)->host_filename)
+ kfree(HOSTFS_I(inode)->host_filename);
+
+ if(HOSTFS_I(inode)->fd != -1)
+ close_file(&HOSTFS_I(inode)->fd);
+
+ kfree(HOSTFS_I(inode));
+}
+
+static void hostfs_read_inode(struct inode *inode)
+{
+ read_inode(inode);
+}
+
+static struct super_operations hostfs_sbops = {
+ .alloc_inode = hostfs_alloc_inode,
+ .destroy_inode = hostfs_destroy_inode,
+ .read_inode = hostfs_read_inode,
+ .statfs = hostfs_statfs,
+};
+
+int hostfs_readdir(struct file *file, void *ent, filldir_t filldir)
+{
+ void *dir;
+ char *name;
+ unsigned long long next, ino;
+ int error, len;
+
+ name = dentry_name(file->f_dentry, 0);
+ if(name == NULL) return(-ENOMEM);
+ dir = open_dir(name, &error);
+ kfree(name);
+ if(dir == NULL) return(-error);
+ next = file->f_pos;
+ while((name = read_dir(dir, &next, &ino, &len)) != NULL){
+ error = (*filldir)(ent, name, len, file->f_pos,
+ ino, DT_UNKNOWN);
+ if(error) break;
+ file->f_pos = next;
+ }
+ close_dir(dir);
+ return(0);
+}
+
+int hostfs_file_open(struct inode *ino, struct file *file)
+{
+ char *name;
+ int mode = 0, r = 0, w = 0, fd;
+
+ mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
+ if((mode & HOSTFS_I(ino)->mode) == mode)
+ return(0);
+
+ /* The file may already have been opened, but with the wrong access,
+ * so this resets things and reopens the file with the new access.
+ */
+ if(HOSTFS_I(ino)->fd != -1){
+ close_file(&HOSTFS_I(ino)->fd);
+ HOSTFS_I(ino)->fd = -1;
+ }
+
+ HOSTFS_I(ino)->mode |= mode;
+ if(HOSTFS_I(ino)->mode & FMODE_READ)
+ r = 1;
+ if(HOSTFS_I(ino)->mode & FMODE_WRITE)
+ w = 1;
+ if(w)
+ r = 1;
+
+ name = dentry_name(file->f_dentry, 0);
+ if(name == NULL)
+ return(-ENOMEM);
+
+ fd = open_file(name, r, w, append);
+ kfree(name);
+ if(fd < 0) return(fd);
+ FILE_HOSTFS_I(file)->fd = fd;
+
+ return(0);
+}
+
+int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync)
+{
+ return(0);
+}
+
+static struct file_operations hostfs_file_fops = {
+ .llseek = generic_file_llseek,
+ .read = generic_file_read,
+ .write = generic_file_write,
+ .mmap = generic_file_mmap,
+ .open = hostfs_file_open,
+ .release = NULL,
+ .fsync = hostfs_fsync,
+};
+
+static struct file_operations hostfs_dir_fops = {
+ .readdir = hostfs_readdir,
+ .read = generic_read_dir,
+};
+
+int hostfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ char *buffer;
+ unsigned long long base;
+ int count = PAGE_CACHE_SIZE;
+ int end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+ int err;
+
+ if (page->index >= end_index)
+ count = inode->i_size & (PAGE_CACHE_SIZE-1);
+
+ buffer = kmap(page);
+ base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT;
+
+ err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
+ if(err != count){
+ ClearPageUptodate(page);
+ goto out;
+ }
+
+ if (base > inode->i_size)
+ inode->i_size = base;
+
+ if (PageError(page))
+ ClearPageError(page);
+ err = 0;
+
+ out:
+ kunmap(page);
+
+ unlock_page(page);
+ return err;
+}
+
+int hostfs_readpage(struct file *file, struct page *page)
+{
+ char *buffer;
+ long long start;
+ int err = 0;
+
+ start = (long long) page->index << PAGE_CACHE_SHIFT;
+ buffer = kmap(page);
+ err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
+ PAGE_CACHE_SIZE);
+ if(err < 0) goto out;
+
+ memset(&buffer[err], 0, PAGE_CACHE_SIZE - err);
+
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ if (PageError(page)) ClearPageError(page);
+ err = 0;
+ out:
+ kunmap(page);
+ unlock_page(page);
+ return(err);
+}
+
+int hostfs_prepare_write(struct file *file, struct page *page,
+ unsigned int from, unsigned int to)
+{
+ char *buffer;
+ long long start, tmp;
+ int err;
+
+ start = (long long) page->index << PAGE_CACHE_SHIFT;
+ buffer = kmap(page);
+ if(from != 0){
+ tmp = start;
+ err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer,
+ from);
+ if(err < 0) goto out;
+ }
+ if(to != PAGE_CACHE_SIZE){
+ start += to;
+ err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to,
+ PAGE_CACHE_SIZE - to);
+ if(err < 0) goto out;
+ }
+ err = 0;
+ out:
+ kunmap(page);
+ return(err);
+}
+
+int hostfs_commit_write(struct file *file, struct page *page, unsigned from,
+ unsigned to)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ char *buffer;
+ long long start;
+ int err = 0;
+
+ start = (long long) (page->index << PAGE_CACHE_SHIFT) + from;
+ buffer = kmap(page);
+ err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from,
+ to - from);
+ if(err > 0) err = 0;
+ if(!err && (start > inode->i_size))
+ inode->i_size = start;
+
+ kunmap(page);
+ return(err);
+}
+
+static struct address_space_operations hostfs_aops = {
+ .writepage = hostfs_writepage,
+ .readpage = hostfs_readpage,
+/* .set_page_dirty = __set_page_dirty_nobuffers, */
+ .prepare_write = hostfs_prepare_write,
+ .commit_write = hostfs_commit_write
+};
+
+static int init_inode(struct inode *inode, struct dentry *dentry)
+{
+ char *name;
+ int type, err = -ENOMEM, rdev;
+
+ if(dentry){
+ name = dentry_name(dentry, 0);
+ if(name == NULL)
+ goto out;
+ type = file_type(name, &rdev);
+ kfree(name);
+ }
+ else type = OS_TYPE_DIR;
+
+ err = 0;
+ if(type == OS_TYPE_SYMLINK)
+ inode->i_op = &page_symlink_inode_operations;
+ else if(type == OS_TYPE_DIR)
+ inode->i_op = &hostfs_dir_iops;
+ else inode->i_op = &hostfs_iops;
+
+ if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops;
+ else inode->i_fop = &hostfs_file_fops;
+
+ if(type == OS_TYPE_SYMLINK)
+ inode->i_mapping->a_ops = &hostfs_link_aops;
+ else inode->i_mapping->a_ops = &hostfs_aops;
+
+ switch (type) {
+ case OS_TYPE_CHARDEV:
+ init_special_inode(inode, S_IFCHR, rdev);
+ break;
+ case OS_TYPE_BLOCKDEV:
+ init_special_inode(inode, S_IFBLK, rdev);
+ break;
+ case OS_TYPE_FIFO:
+ init_special_inode(inode, S_IFIFO, 0);
+ break;
+ case OS_TYPE_SOCK:
+ init_special_inode(inode, S_IFSOCK, 0);
+ break;
+ }
+ out:
+ return(err);
+}
+
+int hostfs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+ char *name;
+ int error, fd;
+
+ error = -ENOMEM;
+ inode = iget(dir->i_sb, 0);
+ if(inode == NULL) goto out;
+
+ error = init_inode(inode, dentry);
+ if(error)
+ goto out_put;
+
+ error = -ENOMEM;
+ name = dentry_name(dentry, 0);
+ if(name == NULL)
+ goto out_put;
+
+ fd = file_create(name,
+ mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR,
+ mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP,
+ mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH);
+ if(fd < 0)
+ error = fd;
+ else error = read_name(inode, name);
+
+ kfree(name);
+ if(error)
+ goto out_put;
+
+ HOSTFS_I(inode)->fd = fd;
+ HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
+ d_instantiate(dentry, inode);
+ return(0);
+
+ out_put:
+ iput(inode);
+ out:
+ return(error);
+}
+
+struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+ char *name;
+ int err;
+
+ err = -ENOMEM;
+ inode = iget(ino->i_sb, 0);
+ if(inode == NULL)
+ goto out;
+
+ err = init_inode(inode, dentry);
+ if(err)
+ goto out_put;
+
+ err = -ENOMEM;
+ name = dentry_name(dentry, 0);
+ if(name == NULL)
+ goto out_put;
+
+ err = read_name(inode, name);
+ kfree(name);
+ if(err == -ENOENT){
+ iput(inode);
+ inode = NULL;
+ }
+ else if(err)
+ goto out_put;
+
+ d_add(dentry, inode);
+ dentry->d_op = &hostfs_dentry_ops;
+ return(NULL);
+
+ out_put:
+ iput(inode);
+ out:
+ return(ERR_PTR(err));
+}
+
+static char *inode_dentry_name(struct inode *ino, struct dentry *dentry)
+{
+ char *file;
+ int len;
+
+ file = inode_name(ino, dentry->d_name.len + 1);
+ if(file == NULL) return(NULL);
+ strcat(file, "/");
+ len = strlen(file);
+ strncat(file, dentry->d_name.name, dentry->d_name.len);
+ file[len + dentry->d_name.len] = '\0';
+ return(file);
+}
+
+int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from)
+{
+ char *from_name, *to_name;
+ int err;
+
+ if((from_name = inode_dentry_name(ino, from)) == NULL)
+ return(-ENOMEM);
+ to_name = dentry_name(to, 0);
+ if(to_name == NULL){
+ kfree(from_name);
+ return(-ENOMEM);
+ }
+ err = link_file(to_name, from_name);
+ kfree(from_name);
+ kfree(to_name);
+ return(err);
+}
+
+int hostfs_unlink(struct inode *ino, struct dentry *dentry)
+{
+ char *file;
+ int err;
+
+ if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
+ if(append)
+ return(-EPERM);
+
+ err = unlink_file(file);
+ kfree(file);
+ return(err);
+}
+
+int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to)
+{
+ char *file;
+ int err;
+
+ if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
+ err = make_symlink(file, to);
+ kfree(file);
+ return(err);
+}
+
+int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode)
+{
+ char *file;
+ int err;
+
+ if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
+ err = do_mkdir(file, mode);
+ kfree(file);
+ return(err);
+}
+
+int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
+{
+ char *file;
+ int err;
+
+ if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
+ err = do_rmdir(file);
+ kfree(file);
+ return(err);
+}
+
+int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+{
+ struct inode *inode;
+ char *name;
+ int err = -ENOMEM;
+
+ inode = iget(dir->i_sb, 0);
+ if(inode == NULL)
+ goto out;
+
+ err = init_inode(inode, dentry);
+ if(err)
+ goto out_put;
+
+ err = -ENOMEM;
+ name = dentry_name(dentry, 0);
+ if(name == NULL)
+ goto out_put;
+
+ init_special_inode(inode, mode, dev);
+ err = do_mknod(name, mode, dev);
+ if(err)
+ goto out_free;
+
+ err = read_name(inode, name);
+ kfree(name);
+ if(err)
+ goto out_put;
+
+ d_instantiate(dentry, inode);
+ return(0);
+
+ out_free:
+ kfree(name);
+ out_put:
+ iput(inode);
+ out:
+ return(err);
+}
+
+int hostfs_rename(struct inode *from_ino, struct dentry *from,
+ struct inode *to_ino, struct dentry *to)
+{
+ char *from_name, *to_name;
+ int err;
+
+ if((from_name = inode_dentry_name(from_ino, from)) == NULL)
+ return(-ENOMEM);
+ if((to_name = inode_dentry_name(to_ino, to)) == NULL){
+ kfree(from_name);
+ return(-ENOMEM);
+ }
+ err = rename_file(from_name, to_name);
+ kfree(from_name);
+ kfree(to_name);
+ return(err);
+}
+
+void hostfs_truncate(struct inode *ino)
+{
+ not_implemented();
+}
+
+int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd)
+{
+ char *name;
+ int r = 0, w = 0, x = 0, err;
+
+ if(desired & MAY_READ) r = 1;
+ if(desired & MAY_WRITE) w = 1;
+ if(desired & MAY_EXEC) x = 1;
+ name = inode_name(ino, 0);
+ if(name == NULL) return(-ENOMEM);
+ err = access_file(name, r, w, x);
+ kfree(name);
+ if(!err) err = vfs_permission(ino, desired);
+ return(err);
+}
+
+int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct hostfs_iattr attrs;
+ char *name;
+ int err;
+
+ if(append)
+ attr->ia_valid &= ~ATTR_SIZE;
+
+ attrs.ia_valid = 0;
+ if(attr->ia_valid & ATTR_MODE){
+ attrs.ia_valid |= HOSTFS_ATTR_MODE;
+ attrs.ia_mode = attr->ia_mode;
+ }
+ if(attr->ia_valid & ATTR_UID){
+ if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
+ (attr->ia_uid == 0))
+ attr->ia_uid = getuid();
+ attrs.ia_valid |= HOSTFS_ATTR_UID;
+ attrs.ia_uid = attr->ia_uid;
+ }
+ if(attr->ia_valid & ATTR_GID){
+ if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
+ (attr->ia_gid == 0))
+ attr->ia_gid = getuid();
+ attrs.ia_valid |= HOSTFS_ATTR_GID;
+ attrs.ia_gid = attr->ia_gid;
+ }
+ if(attr->ia_valid & ATTR_SIZE){
+ attrs.ia_valid |= HOSTFS_ATTR_SIZE;
+ attrs.ia_size = attr->ia_size;
+ }
+ if(attr->ia_valid & ATTR_ATIME){
+ attrs.ia_valid |= HOSTFS_ATTR_ATIME;
+ attrs.ia_atime = attr->ia_atime;
+ }
+ if(attr->ia_valid & ATTR_MTIME){
+ attrs.ia_valid |= HOSTFS_ATTR_MTIME;
+ attrs.ia_mtime = attr->ia_mtime;
+ }
+ if(attr->ia_valid & ATTR_CTIME){
+ attrs.ia_valid |= HOSTFS_ATTR_CTIME;
+ attrs.ia_ctime = attr->ia_ctime;
+ }
+ if(attr->ia_valid & ATTR_ATIME_SET){
+ attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET;
+ }
+ if(attr->ia_valid & ATTR_MTIME_SET){
+ attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET;
+ }
+ name = dentry_name(dentry, 0);
+ if(name == NULL) return(-ENOMEM);
+ err = set_attr(name, &attrs);
+ kfree(name);
+ if(err)
+ return(err);
+
+ return(inode_setattr(dentry->d_inode, attr));
+}
+
+int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+ struct kstat *stat)
+{
+ generic_fillattr(dentry->d_inode, stat);
+ return(0);
+}
+
+static struct inode_operations hostfs_iops = {
+ .create = hostfs_create,
+ .link = hostfs_link,
+ .unlink = hostfs_unlink,
+ .symlink = hostfs_symlink,
+ .mkdir = hostfs_mkdir,
+ .rmdir = hostfs_rmdir,
+ .mknod = hostfs_mknod,
+ .rename = hostfs_rename,
+ .truncate = hostfs_truncate,
+ .permission = hostfs_permission,
+ .setattr = hostfs_setattr,
+ .getattr = hostfs_getattr,
+};
+
+static struct inode_operations hostfs_dir_iops = {
+ .create = hostfs_create,
+ .lookup = hostfs_lookup,
+ .link = hostfs_link,
+ .unlink = hostfs_unlink,
+ .symlink = hostfs_symlink,
+ .mkdir = hostfs_mkdir,
+ .rmdir = hostfs_rmdir,
+ .mknod = hostfs_mknod,
+ .rename = hostfs_rename,
+ .truncate = hostfs_truncate,
+ .permission = hostfs_permission,
+ .setattr = hostfs_setattr,
+ .getattr = hostfs_getattr,
+};
+
+int hostfs_link_readpage(struct file *file, struct page *page)
+{
+ char *buffer, *name;
+ long long start;
+ int err;
+
+ start = page->index << PAGE_CACHE_SHIFT;
+ buffer = kmap(page);
+ name = inode_name(page->mapping->host, 0);
+ if(name == NULL) return(-ENOMEM);
+ err = do_readlink(name, buffer, PAGE_CACHE_SIZE);
+ kfree(name);
+ if(err == PAGE_CACHE_SIZE)
+ err = -E2BIG;
+ else if(err > 0){
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ if (PageError(page)) ClearPageError(page);
+ err = 0;
+ }
+ kunmap(page);
+ unlock_page(page);
+ return(err);
+}
+
+static struct address_space_operations hostfs_link_aops = {
+ .readpage = hostfs_link_readpage,
+};
+
+static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
+{
+ struct inode *root_inode;
+ char *name, *data = d;
+ int err;
+
+ sb->s_blocksize = 1024;
+ sb->s_blocksize_bits = 10;
+ sb->s_magic = HOSTFS_SUPER_MAGIC;
+ sb->s_op = &hostfs_sbops;
+
+ if((data == NULL) || (*data == '\0'))
+ data = root_ino;
+
+ err = -ENOMEM;
+ name = kmalloc(strlen(data) + 1, GFP_KERNEL);
+ if(name == NULL)
+ goto out;
+
+ strcpy(name, data);
+
+ root_inode = iget(sb, 0);
+ if(root_inode == NULL)
+ goto out_free;
+
+ err = init_inode(root_inode, NULL);
+ if(err)
+ goto out_put;
+
+ HOSTFS_I(root_inode)->host_filename = name;
+
+ err = -ENOMEM;
+ sb->s_root = d_alloc_root(root_inode);
+ if(sb->s_root == NULL)
+ goto out_put;
+
+ err = read_inode(root_inode);
+ if(err)
+ goto out_put;
+
+ return(0);
+
+ out_put:
+ iput(root_inode);
+ out_free:
+ kfree(name);
+ out:
+ return(err);
+}
+
+static struct super_block *hostfs_read_sb(struct file_system_type *type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ return(get_sb_nodev(type, flags, data, hostfs_fill_sb_common));
+}
+
+static struct file_system_type hostfs_type = {
+ .owner = THIS_MODULE,
+ .name = "hostfs",
+ .get_sb = hostfs_read_sb,
+ .kill_sb = kill_anon_super,
+ .fs_flags = 0,
+};
+
+static int __init init_hostfs(void)
+{
+ return(register_filesystem(&hostfs_type));
+}
+
+static void __exit exit_hostfs(void)
+{
+ unregister_filesystem(&hostfs_type);
+}
+
+module_init(init_hostfs)
+module_exit(exit_hostfs)
+MODULE_LICENSE("GPL");
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only. This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */
git://git.onelab.eu / linux-2.6.git / blobdiff