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- /*
- * 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/module.h>
- #include <linux/init.h>
- #include <linux/slab.h>
- #include <linux/pagemap.h>
- #include <linux/blkdev.h>
- #include <linux/list.h>
- #include <linux/statfs.h>
- #include <linux/kdev_t.h>
- #include <asm/uaccess.h>
- #include "hostfs.h"
- #include "kern_util.h"
- #include "kern.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_path.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 const struct inode_operations hostfs_iops;
- static const struct inode_operations hostfs_dir_iops;
- static const struct address_space_operations hostfs_link_aops;
- #ifndef MODULE
- 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"
- );
- #endif
- 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_blocks = i_blocks;
- 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, 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 dentry *dentry, 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(dentry->d_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_delete_inode(struct inode *inode)
- {
- truncate_inode_pages(&inode->i_data, 0);
- if(HOSTFS_I(inode)->fd != -1) {
- close_file(&HOSTFS_I(inode)->fd);
- HOSTFS_I(inode)->fd = -1;
- }
- clear_inode(inode);
- }
- static void hostfs_destroy_inode(struct inode *inode)
- {
- kfree(HOSTFS_I(inode)->host_filename);
- /*XXX: This should not happen, probably. The check is here for
- * additional safety.*/
- if(HOSTFS_I(inode)->fd != -1) {
- close_file(&HOSTFS_I(inode)->fd);
- printk(KERN_DEBUG "Closing host fd in .destroy_inode\n");
- }
- kfree(HOSTFS_I(inode));
- }
- static void hostfs_read_inode(struct inode *inode)
- {
- read_inode(inode);
- }
- static const struct super_operations hostfs_sbops = {
- .alloc_inode = hostfs_alloc_inode,
- .drop_inode = generic_delete_inode,
- .delete_inode = hostfs_delete_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_path.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_path.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 fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync);
- }
- static const struct file_operations hostfs_file_fops = {
- .llseek = generic_file_llseek,
- .read = do_sync_read,
- .sendfile = generic_file_sendfile,
- .aio_read = generic_file_aio_read,
- .aio_write = generic_file_aio_write,
- .write = do_sync_write,
- .mmap = generic_file_mmap,
- .open = hostfs_file_open,
- .release = NULL,
- .fsync = hostfs_fsync,
- };
- static const struct file_operations hostfs_dir_fops = {
- .llseek = generic_file_llseek,
- .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;
- /* Actually, if !err, write_file has added to-from to start, so, despite
- * the appearance, we are comparing i_size against the _last_ written
- * location, as we should. */
- if(!err && (start > inode->i_size))
- inode->i_size = start;
- kunmap(page);
- return(err);
- }
- static const 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;
- int maj, min;
- dev_t rdev = 0;
- if(dentry){
- name = dentry_name(dentry, 0);
- if(name == NULL)
- goto out;
- type = file_type(name, &maj, &min);
- /*Reencode maj and min with the kernel encoding.*/
- rdev = MKDEV(maj, min);
- 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, MAJOR(dev), MINOR(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);
- }
- 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);
- if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) ||
- S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode))
- err = 0;
- else
- err = access_file(name, r, w, x);
- kfree(name);
- if(!err)
- err = generic_permission(ino, desired, NULL);
- return err;
- }
- int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
- {
- struct hostfs_iattr attrs;
- char *name;
- int err;
- err = inode_change_ok(dentry->d_inode, attr);
- if (err)
- return 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){
- attrs.ia_valid |= HOSTFS_ATTR_UID;
- attrs.ia_uid = attr->ia_uid;
- }
- if(attr->ia_valid & ATTR_GID){
- 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 const 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,
- .permission = hostfs_permission,
- .setattr = hostfs_setattr,
- .getattr = hostfs_getattr,
- };
- static const 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,
- .permission = hostfs_permission,
- .setattr = hostfs_setattr,
- .getattr = hostfs_getattr,
- };
- int hostfs_link_readpage(struct file *file, struct page *page)
- {
- char *buffer, *name;
- int err;
- 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 const 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 *host_root_path, *req_root = d;
- int err;
- sb->s_blocksize = 1024;
- sb->s_blocksize_bits = 10;
- sb->s_magic = HOSTFS_SUPER_MAGIC;
- sb->s_op = &hostfs_sbops;
- /* NULL is printed as <NULL> by sprintf: avoid that. */
- if (req_root == NULL)
- req_root = "";
- err = -ENOMEM;
- host_root_path = kmalloc(strlen(root_ino) + 1
- + strlen(req_root) + 1, GFP_KERNEL);
- if(host_root_path == NULL)
- goto out;
- sprintf(host_root_path, "%s/%s", root_ino, req_root);
- 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 = host_root_path;
- /* Avoid that in the error path, iput(root_inode) frees again
- * host_root_path through hostfs_destroy_inode! */
- host_root_path = NULL;
- 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){
- /* No iput in this case because the dput does that for us */
- dput(sb->s_root);
- sb->s_root = NULL;
- goto out;
- }
- return(0);
- out_put:
- iput(root_inode);
- out_free:
- kfree(host_root_path);
- out:
- return(err);
- }
- static int hostfs_read_sb(struct file_system_type *type,
- int flags, const char *dev_name,
- void *data, struct vfsmount *mnt)
- {
- return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt);
- }
- 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:
- */
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