| /* |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| * Licensed under the GPL |
| * |
| * Ported the filesystem routines to 2.5. |
| * 2003-02-10 Petr Baudis <pasky@ucw.cz> |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/magic.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/statfs.h> |
| #include <linux/slab.h> |
| #include <linux/seq_file.h> |
| #include <linux/mount.h> |
| #include <linux/namei.h> |
| #include "hostfs.h" |
| #include <init.h> |
| #include <kern.h> |
| |
| struct hostfs_inode_info { |
| int fd; |
| fmode_t mode; |
| struct inode vfs_inode; |
| struct mutex open_mutex; |
| }; |
| |
| 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_inode(file)) |
| |
| /* Changed in hostfs_args before the kernel starts running */ |
| static char *root_ino = ""; |
| static int append = 0; |
| |
| static const struct inode_operations hostfs_iops; |
| static const struct inode_operations hostfs_dir_iops; |
| static const struct inode_operations hostfs_link_iops; |
| |
| #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, char *name) |
| { |
| char *p = dentry_path_raw(dentry, name, PATH_MAX); |
| char *root; |
| size_t len; |
| |
| root = dentry->d_sb->s_fs_info; |
| len = strlen(root); |
| if (IS_ERR(p)) { |
| __putname(name); |
| return NULL; |
| } |
| |
| /* |
| * This function relies on the fact that dentry_path_raw() will place |
| * the path name at the end of the provided buffer. |
| */ |
| BUG_ON(p + strlen(p) + 1 != name + PATH_MAX); |
| |
| strlcpy(name, root, PATH_MAX); |
| if (len > p - name) { |
| __putname(name); |
| return NULL; |
| } |
| |
| if (p > name + len) |
| strcpy(name + len, p); |
| |
| return name; |
| } |
| |
| static char *dentry_name(struct dentry *dentry) |
| { |
| char *name = __getname(); |
| if (!name) |
| return NULL; |
| |
| return __dentry_name(dentry, name); |
| } |
| |
| static char *inode_name(struct inode *ino) |
| { |
| struct dentry *dentry; |
| char *name; |
| |
| dentry = d_find_alias(ino); |
| if (!dentry) |
| return NULL; |
| |
| name = dentry_name(dentry); |
| |
| dput(dentry); |
| |
| return name; |
| } |
| |
| static char *follow_link(char *link) |
| { |
| int len, n; |
| char *name, *resolved, *end; |
| |
| name = __getname(); |
| if (!name) { |
| n = -ENOMEM; |
| goto out_free; |
| } |
| |
| n = hostfs_do_readlink(link, name, PATH_MAX); |
| if (n < 0) |
| goto out_free; |
| else if (n == PATH_MAX) { |
| n = -E2BIG; |
| 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); |
| __putname(name); |
| kfree(link); |
| return resolved; |
| |
| out_free: |
| __putname(name); |
| return ERR_PTR(n); |
| } |
| |
| static struct inode *hostfs_iget(struct super_block *sb) |
| { |
| struct inode *inode = new_inode(sb); |
| if (!inode) |
| return ERR_PTR(-ENOMEM); |
| return inode; |
| } |
| |
| static 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(dentry->d_sb->s_fs_info, |
| &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
| &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), |
| &sf->f_namelen); |
| 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_ACCOUNT); |
| if (hi == NULL) |
| return NULL; |
| hi->fd = -1; |
| hi->mode = 0; |
| inode_init_once(&hi->vfs_inode); |
| mutex_init(&hi->open_mutex); |
| return &hi->vfs_inode; |
| } |
| |
| static void hostfs_evict_inode(struct inode *inode) |
| { |
| truncate_inode_pages_final(&inode->i_data); |
| clear_inode(inode); |
| if (HOSTFS_I(inode)->fd != -1) { |
| close_file(&HOSTFS_I(inode)->fd); |
| HOSTFS_I(inode)->fd = -1; |
| } |
| } |
| |
| static void hostfs_free_inode(struct inode *inode) |
| { |
| kfree(HOSTFS_I(inode)); |
| } |
| |
| static int hostfs_show_options(struct seq_file *seq, struct dentry *root) |
| { |
| const char *root_path = root->d_sb->s_fs_info; |
| size_t offset = strlen(root_ino) + 1; |
| |
| if (strlen(root_path) > offset) |
| seq_show_option(seq, root_path + offset, NULL); |
| |
| if (append) |
| seq_puts(seq, ",append"); |
| |
| return 0; |
| } |
| |
| static const struct super_operations hostfs_sbops = { |
| .alloc_inode = hostfs_alloc_inode, |
| .free_inode = hostfs_free_inode, |
| .evict_inode = hostfs_evict_inode, |
| .statfs = hostfs_statfs, |
| .show_options = hostfs_show_options, |
| }; |
| |
| static int hostfs_readdir(struct file *file, struct dir_context *ctx) |
| { |
| void *dir; |
| char *name; |
| unsigned long long next, ino; |
| int error, len; |
| unsigned int type; |
| |
| name = dentry_name(file->f_path.dentry); |
| if (name == NULL) |
| return -ENOMEM; |
| dir = open_dir(name, &error); |
| __putname(name); |
| if (dir == NULL) |
| return -error; |
| next = ctx->pos; |
| seek_dir(dir, next); |
| while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { |
| if (!dir_emit(ctx, name, len, ino, type)) |
| break; |
| ctx->pos = next; |
| } |
| close_dir(dir); |
| return 0; |
| } |
| |
| static int hostfs_open(struct inode *ino, struct file *file) |
| { |
| char *name; |
| fmode_t mode; |
| int err; |
| int r, w, fd; |
| |
| mode = file->f_mode & (FMODE_READ | FMODE_WRITE); |
| if ((mode & HOSTFS_I(ino)->mode) == mode) |
| return 0; |
| |
| mode |= HOSTFS_I(ino)->mode; |
| |
| retry: |
| r = w = 0; |
| |
| if (mode & FMODE_READ) |
| r = 1; |
| if (mode & FMODE_WRITE) |
| r = w = 1; |
| |
| name = dentry_name(file->f_path.dentry); |
| if (name == NULL) |
| return -ENOMEM; |
| |
| fd = open_file(name, r, w, append); |
| __putname(name); |
| if (fd < 0) |
| return fd; |
| |
| mutex_lock(&HOSTFS_I(ino)->open_mutex); |
| /* somebody else had handled it first? */ |
| if ((mode & HOSTFS_I(ino)->mode) == mode) { |
| mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
| close_file(&fd); |
| return 0; |
| } |
| if ((mode | HOSTFS_I(ino)->mode) != mode) { |
| mode |= HOSTFS_I(ino)->mode; |
| mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
| close_file(&fd); |
| goto retry; |
| } |
| if (HOSTFS_I(ino)->fd == -1) { |
| HOSTFS_I(ino)->fd = fd; |
| } else { |
| err = replace_file(fd, HOSTFS_I(ino)->fd); |
| close_file(&fd); |
| if (err < 0) { |
| mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
| return err; |
| } |
| } |
| HOSTFS_I(ino)->mode = mode; |
| mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
| |
| return 0; |
| } |
| |
| static int hostfs_file_release(struct inode *inode, struct file *file) |
| { |
| filemap_write_and_wait(inode->i_mapping); |
| |
| return 0; |
| } |
| |
| static int hostfs_fsync(struct file *file, loff_t start, loff_t end, |
| int datasync) |
| { |
| struct inode *inode = file->f_mapping->host; |
| int ret; |
| |
| ret = file_write_and_wait_range(file, start, end); |
| if (ret) |
| return ret; |
| |
| inode_lock(inode); |
| ret = fsync_file(HOSTFS_I(inode)->fd, datasync); |
| inode_unlock(inode); |
| |
| return ret; |
| } |
| |
| static const struct file_operations hostfs_file_fops = { |
| .llseek = generic_file_llseek, |
| .splice_read = generic_file_splice_read, |
| .read_iter = generic_file_read_iter, |
| .write_iter = generic_file_write_iter, |
| .mmap = generic_file_mmap, |
| .open = hostfs_open, |
| .release = hostfs_file_release, |
| .fsync = hostfs_fsync, |
| }; |
| |
| static const struct file_operations hostfs_dir_fops = { |
| .llseek = generic_file_llseek, |
| .iterate_shared = hostfs_readdir, |
| .read = generic_read_dir, |
| .open = hostfs_open, |
| .fsync = hostfs_fsync, |
| }; |
| |
| static int hostfs_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| char *buffer; |
| loff_t base = page_offset(page); |
| int count = PAGE_SIZE; |
| int end_index = inode->i_size >> PAGE_SHIFT; |
| int err; |
| |
| if (page->index >= end_index) |
| count = inode->i_size & (PAGE_SIZE-1); |
| |
| buffer = kmap(page); |
| |
| 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; |
| } |
| |
| static int hostfs_readpage(struct file *file, struct page *page) |
| { |
| char *buffer; |
| loff_t start = page_offset(page); |
| int bytes_read, ret = 0; |
| |
| buffer = kmap(page); |
| bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, |
| PAGE_SIZE); |
| if (bytes_read < 0) { |
| ClearPageUptodate(page); |
| SetPageError(page); |
| ret = bytes_read; |
| goto out; |
| } |
| |
| memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read); |
| |
| ClearPageError(page); |
| SetPageUptodate(page); |
| |
| out: |
| flush_dcache_page(page); |
| kunmap(page); |
| unlock_page(page); |
| return ret; |
| } |
| |
| static int hostfs_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| pgoff_t index = pos >> PAGE_SHIFT; |
| |
| *pagep = grab_cache_page_write_begin(mapping, index, flags); |
| if (!*pagep) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| static int hostfs_write_end(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| struct inode *inode = mapping->host; |
| void *buffer; |
| unsigned from = pos & (PAGE_SIZE - 1); |
| int err; |
| |
| buffer = kmap(page); |
| err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
| kunmap(page); |
| |
| if (!PageUptodate(page) && err == PAGE_SIZE) |
| SetPageUptodate(page); |
| |
| /* |
| * If err > 0, write_file has added err to pos, so we are comparing |
| * i_size against the last byte written. |
| */ |
| if (err > 0 && (pos > inode->i_size)) |
| inode->i_size = pos; |
| unlock_page(page); |
| put_page(page); |
| |
| return err; |
| } |
| |
| static const struct address_space_operations hostfs_aops = { |
| .writepage = hostfs_writepage, |
| .readpage = hostfs_readpage, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .write_begin = hostfs_write_begin, |
| .write_end = hostfs_write_end, |
| }; |
| |
| static int read_name(struct inode *ino, char *name) |
| { |
| dev_t rdev; |
| struct hostfs_stat st; |
| int err = stat_file(name, &st, -1); |
| if (err) |
| return err; |
| |
| /* Reencode maj and min with the kernel encoding.*/ |
| rdev = MKDEV(st.maj, st.min); |
| |
| switch (st.mode & S_IFMT) { |
| case S_IFLNK: |
| ino->i_op = &hostfs_link_iops; |
| break; |
| case S_IFDIR: |
| ino->i_op = &hostfs_dir_iops; |
| ino->i_fop = &hostfs_dir_fops; |
| break; |
| case S_IFCHR: |
| case S_IFBLK: |
| case S_IFIFO: |
| case S_IFSOCK: |
| init_special_inode(ino, st.mode & S_IFMT, rdev); |
| ino->i_op = &hostfs_iops; |
| break; |
| case S_IFREG: |
| ino->i_op = &hostfs_iops; |
| ino->i_fop = &hostfs_file_fops; |
| ino->i_mapping->a_ops = &hostfs_aops; |
| break; |
| default: |
| return -EIO; |
| } |
| |
| ino->i_ino = st.ino; |
| ino->i_mode = st.mode; |
| set_nlink(ino, st.nlink); |
| i_uid_write(ino, st.uid); |
| i_gid_write(ino, st.gid); |
| ino->i_atime = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec }; |
| ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec }; |
| ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec }; |
| ino->i_size = st.size; |
| ino->i_blocks = st.blocks; |
| return 0; |
| } |
| |
| static int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
| bool excl) |
| { |
| struct inode *inode; |
| char *name; |
| int error, fd; |
| |
| inode = hostfs_iget(dir->i_sb); |
| if (IS_ERR(inode)) { |
| error = PTR_ERR(inode); |
| goto out; |
| } |
| |
| error = -ENOMEM; |
| name = dentry_name(dentry); |
| if (name == NULL) |
| goto out_put; |
| |
| fd = file_create(name, mode & 0777); |
| if (fd < 0) |
| error = fd; |
| else |
| error = read_name(inode, name); |
| |
| __putname(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; |
| } |
| |
| static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, |
| unsigned int flags) |
| { |
| struct inode *inode; |
| char *name; |
| int err; |
| |
| inode = hostfs_iget(ino->i_sb); |
| if (IS_ERR(inode)) |
| goto out; |
| |
| err = -ENOMEM; |
| name = dentry_name(dentry); |
| if (name) { |
| err = read_name(inode, name); |
| __putname(name); |
| } |
| if (err) { |
| iput(inode); |
| inode = (err == -ENOENT) ? NULL : ERR_PTR(err); |
| } |
| out: |
| return d_splice_alias(inode, dentry); |
| } |
| |
| static int hostfs_link(struct dentry *to, struct inode *ino, |
| struct dentry *from) |
| { |
| char *from_name, *to_name; |
| int err; |
| |
| if ((from_name = dentry_name(from)) == NULL) |
| return -ENOMEM; |
| to_name = dentry_name(to); |
| if (to_name == NULL) { |
| __putname(from_name); |
| return -ENOMEM; |
| } |
| err = link_file(to_name, from_name); |
| __putname(from_name); |
| __putname(to_name); |
| return err; |
| } |
| |
| static int hostfs_unlink(struct inode *ino, struct dentry *dentry) |
| { |
| char *file; |
| int err; |
| |
| if (append) |
| return -EPERM; |
| |
| if ((file = dentry_name(dentry)) == NULL) |
| return -ENOMEM; |
| |
| err = unlink_file(file); |
| __putname(file); |
| return err; |
| } |
| |
| static int hostfs_symlink(struct inode *ino, struct dentry *dentry, |
| const char *to) |
| { |
| char *file; |
| int err; |
| |
| if ((file = dentry_name(dentry)) == NULL) |
| return -ENOMEM; |
| err = make_symlink(file, to); |
| __putname(file); |
| return err; |
| } |
| |
| static int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) |
| { |
| char *file; |
| int err; |
| |
| if ((file = dentry_name(dentry)) == NULL) |
| return -ENOMEM; |
| err = do_mkdir(file, mode); |
| __putname(file); |
| return err; |
| } |
| |
| static int hostfs_rmdir(struct inode *ino, struct dentry *dentry) |
| { |
| char *file; |
| int err; |
| |
| if ((file = dentry_name(dentry)) == NULL) |
| return -ENOMEM; |
| err = hostfs_do_rmdir(file); |
| __putname(file); |
| return err; |
| } |
| |
| static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
| { |
| struct inode *inode; |
| char *name; |
| int err; |
| |
| inode = hostfs_iget(dir->i_sb); |
| if (IS_ERR(inode)) { |
| err = PTR_ERR(inode); |
| goto out; |
| } |
| |
| err = -ENOMEM; |
| name = dentry_name(dentry); |
| 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); |
| __putname(name); |
| if (err) |
| goto out_put; |
| |
| d_instantiate(dentry, inode); |
| return 0; |
| |
| out_free: |
| __putname(name); |
| out_put: |
| iput(inode); |
| out: |
| return err; |
| } |
| |
| static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry, |
| struct inode *new_dir, struct dentry *new_dentry, |
| unsigned int flags) |
| { |
| char *old_name, *new_name; |
| int err; |
| |
| if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) |
| return -EINVAL; |
| |
| old_name = dentry_name(old_dentry); |
| if (old_name == NULL) |
| return -ENOMEM; |
| new_name = dentry_name(new_dentry); |
| if (new_name == NULL) { |
| __putname(old_name); |
| return -ENOMEM; |
| } |
| if (!flags) |
| err = rename_file(old_name, new_name); |
| else |
| err = rename2_file(old_name, new_name, flags); |
| |
| __putname(old_name); |
| __putname(new_name); |
| return err; |
| } |
| |
| static int hostfs_permission(struct inode *ino, int desired) |
| { |
| char *name; |
| int r = 0, w = 0, x = 0, err; |
| |
| if (desired & MAY_NOT_BLOCK) |
| return -ECHILD; |
| |
| if (desired & MAY_READ) r = 1; |
| if (desired & MAY_WRITE) w = 1; |
| if (desired & MAY_EXEC) x = 1; |
| name = inode_name(ino); |
| 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); |
| __putname(name); |
| if (!err) |
| err = generic_permission(ino, desired); |
| return err; |
| } |
| |
| static int hostfs_setattr(struct dentry *dentry, struct iattr *attr) |
| { |
| struct inode *inode = d_inode(dentry); |
| struct hostfs_iattr attrs; |
| char *name; |
| int err; |
| |
| int fd = HOSTFS_I(inode)->fd; |
| |
| err = setattr_prepare(dentry, 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 = from_kuid(&init_user_ns, attr->ia_uid); |
| } |
| if (attr->ia_valid & ATTR_GID) { |
| attrs.ia_valid |= HOSTFS_ATTR_GID; |
| attrs.ia_gid = from_kgid(&init_user_ns, 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 = (struct hostfs_timespec) |
| { attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec }; |
| } |
| if (attr->ia_valid & ATTR_MTIME) { |
| attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
| attrs.ia_mtime = (struct hostfs_timespec) |
| { attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec }; |
| } |
| if (attr->ia_valid & ATTR_CTIME) { |
| attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
| attrs.ia_ctime = (struct hostfs_timespec) |
| { attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec }; |
| } |
| 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); |
| if (name == NULL) |
| return -ENOMEM; |
| err = set_attr(name, &attrs, fd); |
| __putname(name); |
| if (err) |
| return err; |
| |
| if ((attr->ia_valid & ATTR_SIZE) && |
| attr->ia_size != i_size_read(inode)) |
| truncate_setsize(inode, attr->ia_size); |
| |
| setattr_copy(inode, attr); |
| mark_inode_dirty(inode); |
| return 0; |
| } |
| |
| static const struct inode_operations hostfs_iops = { |
| .permission = hostfs_permission, |
| .setattr = hostfs_setattr, |
| }; |
| |
| 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_rename2, |
| .permission = hostfs_permission, |
| .setattr = hostfs_setattr, |
| }; |
| |
| static const char *hostfs_get_link(struct dentry *dentry, |
| struct inode *inode, |
| struct delayed_call *done) |
| { |
| char *link; |
| if (!dentry) |
| return ERR_PTR(-ECHILD); |
| link = kmalloc(PATH_MAX, GFP_KERNEL); |
| if (link) { |
| char *path = dentry_name(dentry); |
| int err = -ENOMEM; |
| if (path) { |
| err = hostfs_do_readlink(path, link, PATH_MAX); |
| if (err == PATH_MAX) |
| err = -E2BIG; |
| __putname(path); |
| } |
| if (err < 0) { |
| kfree(link); |
| return ERR_PTR(err); |
| } |
| } else { |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| set_delayed_call(done, kfree_link, link); |
| return link; |
| } |
| |
| static const struct inode_operations hostfs_link_iops = { |
| .get_link = hostfs_get_link, |
| }; |
| |
| 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; |
| sb->s_d_op = &simple_dentry_operations; |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| |
| /* NULL is printed as <NULL> by sprintf: avoid that. */ |
| if (req_root == NULL) |
| req_root = ""; |
| |
| err = -ENOMEM; |
| sb->s_fs_info = host_root_path = |
| kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); |
| if (host_root_path == NULL) |
| goto out; |
| |
| sprintf(host_root_path, "%s/%s", root_ino, req_root); |
| |
| root_inode = new_inode(sb); |
| if (!root_inode) |
| goto out; |
| |
| err = read_name(root_inode, host_root_path); |
| if (err) |
| goto out_put; |
| |
| if (S_ISLNK(root_inode->i_mode)) { |
| char *name = follow_link(host_root_path); |
| if (IS_ERR(name)) { |
| err = PTR_ERR(name); |
| goto out_put; |
| } |
| err = read_name(root_inode, name); |
| kfree(name); |
| if (err) |
| goto out_put; |
| } |
| |
| err = -ENOMEM; |
| sb->s_root = d_make_root(root_inode); |
| if (sb->s_root == NULL) |
| goto out; |
| |
| return 0; |
| |
| out_put: |
| iput(root_inode); |
| out: |
| return err; |
| } |
| |
| static struct dentry *hostfs_read_sb(struct file_system_type *type, |
| int flags, const char *dev_name, |
| void *data) |
| { |
| return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
| } |
| |
| static void hostfs_kill_sb(struct super_block *s) |
| { |
| kill_anon_super(s); |
| kfree(s->s_fs_info); |
| } |
| |
| static struct file_system_type hostfs_type = { |
| .owner = THIS_MODULE, |
| .name = "hostfs", |
| .mount = hostfs_read_sb, |
| .kill_sb = hostfs_kill_sb, |
| .fs_flags = 0, |
| }; |
| MODULE_ALIAS_FS("hostfs"); |
| |
| 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"); |