diff options
Diffstat (limited to 'fs/hostfs')
| -rw-r--r-- | fs/hostfs/Makefile | 13 | ||||
| -rw-r--r-- | fs/hostfs/hostfs.h | 73 | ||||
| -rw-r--r-- | fs/hostfs/hostfs_kern.c | 1096 | ||||
| -rw-r--r-- | fs/hostfs/hostfs_user.c | 421 | ||||
| -rw-r--r-- | fs/hostfs/hostfs_user_exp.c | 28 |
5 files changed, 1631 insertions, 0 deletions
diff --git a/fs/hostfs/Makefile b/fs/hostfs/Makefile new file mode 100644 index 000000000..16be592e8 --- /dev/null +++ b/fs/hostfs/Makefile @@ -0,0 +1,13 @@ +# +# Copyright (C) 2000 Jeff Dike (jdike@karaya.com) +# Licensed under the GPL +# + +hostfs-objs := hostfs_kern.o + +hostfs-builtin-$(CONFIG_HOSTFS) += hostfs_user.o hostfs_user_exp.o + +obj-y := $(hostfs-builtin-y) $(hostfs-builtin-m) +obj-$(CONFIG_HOSTFS) += hostfs.o + +include $(srctree)/arch/um/scripts/Makefile.rules diff --git a/fs/hostfs/hostfs.h b/fs/hostfs/hostfs.h new file mode 100644 index 000000000..aa02599b7 --- /dev/null +++ b/fs/hostfs/hostfs.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __UM_FS_HOSTFS +#define __UM_FS_HOSTFS + +#include <os.h> +#include <generated/asm-offsets.h> + +struct hostfs_timespec { + long long tv_sec; + long long tv_nsec; +}; + +struct hostfs_iattr { + unsigned int ia_valid; + unsigned short ia_mode; + uid_t ia_uid; + gid_t ia_gid; + loff_t ia_size; + struct hostfs_timespec ia_atime; + struct hostfs_timespec ia_mtime; + struct hostfs_timespec ia_ctime; +}; + +struct hostfs_stat { + unsigned long long ino; + unsigned int mode; + unsigned int nlink; + unsigned int uid; + unsigned int gid; + unsigned long long size; + struct hostfs_timespec atime, mtime, ctime, btime; + unsigned int blksize; + unsigned long long blocks; + struct { + unsigned int maj; + unsigned int min; + } rdev, dev; +}; + +extern int stat_file(const char *path, struct hostfs_stat *p, int fd); +extern int access_file(char *path, int r, int w, int x); +extern int open_file(char *path, int r, int w, int append); +extern void *open_dir(char *path, int *err_out); +extern void seek_dir(void *stream, unsigned long long pos); +extern char *read_dir(void *stream, unsigned long long *pos_out, + unsigned long long *ino_out, int *len_out, + unsigned int *type_out); +extern void close_file(void *stream); +extern int replace_file(int oldfd, int fd); +extern void close_dir(void *stream); +extern int read_file(int fd, unsigned long long *offset, char *buf, int len); +extern int write_file(int fd, unsigned long long *offset, const char *buf, + int len); +extern int lseek_file(int fd, long long offset, int whence); +extern int fsync_file(int fd, int datasync); +extern int file_create(char *name, int mode); +extern int set_attr(const char *file, struct hostfs_iattr *attrs, int fd); +extern int make_symlink(const char *from, const char *to); +extern int unlink_file(const char *file); +extern int do_mkdir(const char *file, int mode); +extern int hostfs_do_rmdir(const char *file); +extern int do_mknod(const char *file, int mode, unsigned int major, + unsigned int minor); +extern int link_file(const char *to, const char *from); +extern int hostfs_do_readlink(char *file, char *buf, int size); +extern int rename_file(char *from, char *to); +extern int rename2_file(char *from, char *to, unsigned int flags); +extern int do_statfs(char *root, long *bsize_out, long long *blocks_out, + long long *bfree_out, long long *bavail_out, + long long *files_out, long long *ffree_out, + void *fsid_out, int fsid_size, long *namelen_out); + +#endif diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c new file mode 100644 index 000000000..7add056d4 --- /dev/null +++ b/fs/hostfs/hostfs_kern.c @@ -0,0 +1,1096 @@ +/* + * 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/writeback.h> +#include <linux/mount.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include <linux/namei.h> +#include "hostfs.h" +#include <init.h> +#include <kern.h> + +struct hostfs_fs_info { + char *host_root_path; +}; + +struct hostfs_inode_info { + int fd; + fmode_t mode; + struct inode vfs_inode; + struct mutex open_mutex; + dev_t dev; + struct hostfs_timespec btime; +}; + +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)) + +static struct kmem_cache *hostfs_inode_cache; + +/* 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; + + *add = 0; + 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); + struct hostfs_fs_info *fsi = dentry->d_sb->s_fs_info; + char *root = fsi->host_root_path; + size_t len = strlen(root); + + if (IS_ERR(p) || len > p - name) { + __putname(name); + return NULL; + } + + memcpy(name, root, len); + memmove(name + len, p, name + PATH_MAX - 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) +{ + char *name, *resolved, *end; + int n; + + name = kmalloc(PATH_MAX, GFP_KERNEL); + 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'; + + resolved = kasprintf(GFP_KERNEL, "%s%s", link, name); + if (resolved == NULL) { + n = -ENOMEM; + goto out_free; + } + + kfree(name); + return resolved; + + out_free: + kfree(name); + return ERR_PTR(n); +} + +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; + struct hostfs_fs_info *fsi; + + fsi = dentry->d_sb->s_fs_info; + err = do_statfs(fsi->host_root_path, + &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 = alloc_inode_sb(sb, hostfs_inode_cache, GFP_KERNEL_ACCOUNT); + if (hi == NULL) + return NULL; + hi->fd = -1; + hi->mode = 0; + hi->dev = 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; + HOSTFS_I(inode)->dev = 0; + } +} + +static void hostfs_free_inode(struct inode *inode) +{ + kmem_cache_free(hostfs_inode_cache, HOSTFS_I(inode)); +} + +static int hostfs_show_options(struct seq_file *seq, struct dentry *root) +{ + struct hostfs_fs_info *fsi; + const char *root_path; + + fsi = root->d_sb->s_fs_info; + root_path = fsi->host_root_path; + 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, + .drop_inode = inode_just_drop, + .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_dentry(file)); + 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 = filemap_splice_read, + .splice_write = iter_file_splice_write, + .read_iter = generic_file_read_iter, + .write_iter = generic_file_write_iter, + .mmap_prepare = generic_file_mmap_prepare, + .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_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct inode *inode = mapping->host; + struct folio *folio = NULL; + loff_t i_size = i_size_read(inode); + int err = 0; + + while ((folio = writeback_iter(mapping, wbc, folio, &err))) { + loff_t pos = folio_pos(folio); + size_t count = folio_size(folio); + char *buffer; + int ret; + + if (count > i_size - pos) + count = i_size - pos; + + buffer = kmap_local_folio(folio, 0); + ret = write_file(HOSTFS_I(inode)->fd, &pos, buffer, count); + kunmap_local(buffer); + folio_unlock(folio); + if (ret != count) { + err = ret < 0 ? ret : -EIO; + mapping_set_error(mapping, err); + } + } + + return err; +} + +static int hostfs_read_folio(struct file *file, struct folio *folio) +{ + char *buffer; + loff_t start = folio_pos(folio); + int bytes_read, ret = 0; + + buffer = kmap_local_folio(folio, 0); + bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, + PAGE_SIZE); + if (bytes_read < 0) + ret = bytes_read; + else + buffer = folio_zero_tail(folio, bytes_read, buffer + bytes_read); + kunmap_local(buffer); + + folio_end_read(folio, ret == 0); + return ret; +} + +static int hostfs_write_begin(const struct kiocb *iocb, + struct address_space *mapping, + loff_t pos, unsigned len, + struct folio **foliop, void **fsdata) +{ + pgoff_t index = pos >> PAGE_SHIFT; + + *foliop = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN, + mapping_gfp_mask(mapping)); + if (IS_ERR(*foliop)) + return PTR_ERR(*foliop); + return 0; +} + +static int hostfs_write_end(const struct kiocb *iocb, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct folio *folio, void *fsdata) +{ + struct inode *inode = mapping->host; + void *buffer; + size_t from = offset_in_folio(folio, pos); + int err; + + buffer = kmap_local_folio(folio, from); + err = write_file(FILE_HOSTFS_I(iocb->ki_filp)->fd, &pos, buffer, copied); + kunmap_local(buffer); + + if (!folio_test_uptodate(folio) && err == folio_size(folio)) + folio_mark_uptodate(folio); + + /* + * 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; + folio_unlock(folio); + folio_put(folio); + + return err; +} + +static const struct address_space_operations hostfs_aops = { + .writepages = hostfs_writepages, + .read_folio = hostfs_read_folio, + .dirty_folio = filemap_dirty_folio, + .write_begin = hostfs_write_begin, + .write_end = hostfs_write_end, + .migrate_folio = filemap_migrate_folio, +}; + +static int hostfs_inode_update(struct inode *ino, const struct hostfs_stat *st) +{ + set_nlink(ino, st->nlink); + i_uid_write(ino, st->uid); + i_gid_write(ino, st->gid); + inode_set_atime_to_ts(ino, (struct timespec64){ + st->atime.tv_sec, + st->atime.tv_nsec, + }); + inode_set_mtime_to_ts(ino, (struct timespec64){ + st->mtime.tv_sec, + st->mtime.tv_nsec, + }); + inode_set_ctime(ino, st->ctime.tv_sec, st->ctime.tv_nsec); + ino->i_size = st->size; + ino->i_blocks = st->blocks; + return 0; +} + +static int hostfs_inode_set(struct inode *ino, void *data) +{ + struct hostfs_stat *st = data; + dev_t dev, rdev; + + /* Reencode maj and min with the kernel encoding.*/ + rdev = MKDEV(st->rdev.maj, st->rdev.min); + dev = MKDEV(st->dev.maj, st->dev.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; + } + + HOSTFS_I(ino)->dev = dev; + HOSTFS_I(ino)->btime = st->btime; + ino->i_ino = st->ino; + ino->i_mode = st->mode; + return hostfs_inode_update(ino, st); +} + +static int hostfs_inode_test(struct inode *inode, void *data) +{ + const struct hostfs_stat *st = data; + dev_t dev = MKDEV(st->dev.maj, st->dev.min); + + return inode->i_ino == st->ino && HOSTFS_I(inode)->dev == dev && + (inode->i_mode & S_IFMT) == (st->mode & S_IFMT) && + HOSTFS_I(inode)->btime.tv_sec == st->btime.tv_sec && + HOSTFS_I(inode)->btime.tv_nsec == st->btime.tv_nsec; +} + +static struct inode *hostfs_iget(struct super_block *sb, char *name) +{ + struct inode *inode; + struct hostfs_stat st; + int err = stat_file(name, &st, -1); + + if (err) + return ERR_PTR(err); + + inode = iget5_locked(sb, st.ino, hostfs_inode_test, hostfs_inode_set, + &st); + if (!inode) + return ERR_PTR(-ENOMEM); + + if (inode_state_read_once(inode) & I_NEW) { + unlock_new_inode(inode); + } else { + spin_lock(&inode->i_lock); + hostfs_inode_update(inode, &st); + spin_unlock(&inode->i_lock); + } + + return inode; +} + +static int hostfs_create(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode) +{ + struct inode *inode; + char *name; + int fd; + + name = dentry_name(dentry); + if (name == NULL) + return -ENOMEM; + + fd = file_create(name, mode & 0777); + if (fd < 0) { + __putname(name); + return fd; + } + + inode = hostfs_iget(dir->i_sb, name); + __putname(name); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + HOSTFS_I(inode)->fd = fd; + HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; + d_instantiate(dentry, inode); + return 0; +} + +static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, + unsigned int flags) +{ + struct inode *inode = NULL; + char *name; + + name = dentry_name(dentry); + if (name == NULL) + return ERR_PTR(-ENOMEM); + + inode = hostfs_iget(ino->i_sb, name); + __putname(name); + if (inode == ERR_PTR(-ENOENT)) + inode = NULL; + + 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 mnt_idmap *idmap, 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 struct dentry *hostfs_mkdir(struct mnt_idmap *idmap, struct inode *ino, + struct dentry *dentry, umode_t mode) +{ + struct inode *inode; + char *file; + int err; + + if ((file = dentry_name(dentry)) == NULL) + return ERR_PTR(-ENOMEM); + err = do_mkdir(file, mode); + if (err) { + dentry = ERR_PTR(err); + } else { + inode = hostfs_iget(dentry->d_sb, file); + d_drop(dentry); + dentry = d_splice_alias(inode, dentry); + } + __putname(file); + return dentry; +} + +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 mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode, dev_t dev) +{ + struct inode *inode; + char *name; + int err; + + name = dentry_name(dentry); + if (name == NULL) + return -ENOMEM; + + err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); + if (err) { + __putname(name); + return err; + } + + inode = hostfs_iget(dir->i_sb, name); + __putname(name); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + d_instantiate(dentry, inode); + return 0; +} + +static int hostfs_rename2(struct mnt_idmap *idmap, + 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 mnt_idmap *idmap, + 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(&nop_mnt_idmap, ino, desired); + return err; +} + +static int hostfs_setattr(struct mnt_idmap *idmap, + 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(&nop_mnt_idmap, 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(&nop_mnt_idmap, 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_super(struct super_block *sb, struct fs_context *fc) +{ + struct hostfs_fs_info *fsi = sb->s_fs_info; + struct inode *root_inode; + 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_flags = DCACHE_DONTCACHE; + sb->s_maxbytes = MAX_LFS_FILESIZE; + err = super_setup_bdi(sb); + if (err) + return err; + + root_inode = hostfs_iget(sb, fsi->host_root_path); + if (IS_ERR(root_inode)) + return PTR_ERR(root_inode); + + if (S_ISLNK(root_inode->i_mode)) { + char *name; + + iput(root_inode); + name = follow_link(fsi->host_root_path); + if (IS_ERR(name)) + return PTR_ERR(name); + + root_inode = hostfs_iget(sb, name); + kfree(name); + if (IS_ERR(root_inode)) + return PTR_ERR(root_inode); + } + + sb->s_root = d_make_root(root_inode); + if (sb->s_root == NULL) + return -ENOMEM; + + return 0; +} + +enum hostfs_parma { + Opt_hostfs, +}; + +static const struct fs_parameter_spec hostfs_param_specs[] = { + fsparam_string_empty("hostfs", Opt_hostfs), + {} +}; + +static int hostfs_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct hostfs_fs_info *fsi = fc->s_fs_info; + struct fs_parse_result result; + char *host_root, *tmp_root; + int opt; + + opt = fs_parse(fc, hostfs_param_specs, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_hostfs: + host_root = param->string; + if (!*host_root) + break; + tmp_root = kasprintf(GFP_KERNEL, "%s%s", + fsi->host_root_path, host_root); + if (!tmp_root) + return -ENOMEM; + kfree(fsi->host_root_path); + fsi->host_root_path = tmp_root; + break; + } + + return 0; +} + +static int hostfs_parse_monolithic(struct fs_context *fc, void *data) +{ + struct hostfs_fs_info *fsi = fc->s_fs_info; + char *tmp_root, *host_root = (char *)data; + + /* NULL is printed as '(null)' by printf(): avoid that. */ + if (host_root == NULL) + return 0; + + tmp_root = kasprintf(GFP_KERNEL, "%s%s", fsi->host_root_path, host_root); + if (!tmp_root) + return -ENOMEM; + kfree(fsi->host_root_path); + fsi->host_root_path = tmp_root; + return 0; +} + +static int hostfs_fc_get_tree(struct fs_context *fc) +{ + return get_tree_nodev(fc, hostfs_fill_super); +} + +static void hostfs_fc_free(struct fs_context *fc) +{ + struct hostfs_fs_info *fsi = fc->s_fs_info; + + if (!fsi) + return; + + kfree(fsi->host_root_path); + kfree(fsi); +} + +static const struct fs_context_operations hostfs_context_ops = { + .parse_monolithic = hostfs_parse_monolithic, + .parse_param = hostfs_parse_param, + .get_tree = hostfs_fc_get_tree, + .free = hostfs_fc_free, +}; + +static int hostfs_init_fs_context(struct fs_context *fc) +{ + struct hostfs_fs_info *fsi; + + fsi = kzalloc_obj(*fsi); + if (!fsi) + return -ENOMEM; + + fsi->host_root_path = kasprintf(GFP_KERNEL, "%s/", root_ino); + if (!fsi->host_root_path) { + kfree(fsi); + return -ENOMEM; + } + fc->s_fs_info = fsi; + fc->ops = &hostfs_context_ops; + return 0; +} + +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", + .init_fs_context = hostfs_init_fs_context, + .kill_sb = hostfs_kill_sb, + .fs_flags = 0, +}; +MODULE_ALIAS_FS("hostfs"); + +static int __init init_hostfs(void) +{ + hostfs_inode_cache = KMEM_CACHE(hostfs_inode_info, 0); + if (!hostfs_inode_cache) + return -ENOMEM; + return register_filesystem(&hostfs_type); +} + +static void __exit exit_hostfs(void) +{ + unregister_filesystem(&hostfs_type); + kmem_cache_destroy(hostfs_inode_cache); +} + +module_init(init_hostfs) +module_exit(exit_hostfs) +MODULE_DESCRIPTION("User-Mode Linux Host filesystem"); +MODULE_LICENSE("GPL"); diff --git a/fs/hostfs/hostfs_user.c b/fs/hostfs/hostfs_user.c new file mode 100644 index 000000000..3bcd9f35e --- /dev/null +++ b/fs/hostfs/hostfs_user.c @@ -0,0 +1,421 @@ +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <stdio.h> +#include <stddef.h> +#include <unistd.h> +#include <dirent.h> +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/vfs.h> +#include <sys/syscall.h> +#include "hostfs.h" +#include <utime.h> + +static void statx_to_hostfs(const struct statx *buf, struct hostfs_stat *p) +{ + p->ino = buf->stx_ino; + p->mode = buf->stx_mode; + p->nlink = buf->stx_nlink; + p->uid = buf->stx_uid; + p->gid = buf->stx_gid; + p->size = buf->stx_size; + p->atime.tv_sec = buf->stx_atime.tv_sec; + p->atime.tv_nsec = buf->stx_atime.tv_nsec; + p->ctime.tv_sec = buf->stx_ctime.tv_sec; + p->ctime.tv_nsec = buf->stx_ctime.tv_nsec; + p->mtime.tv_sec = buf->stx_mtime.tv_sec; + p->mtime.tv_nsec = buf->stx_mtime.tv_nsec; + if (buf->stx_mask & STATX_BTIME) { + p->btime.tv_sec = buf->stx_btime.tv_sec; + p->btime.tv_nsec = buf->stx_btime.tv_nsec; + } else { + memset(&p->btime, 0, sizeof(p->btime)); + } + p->blksize = buf->stx_blksize; + p->blocks = buf->stx_blocks; + p->rdev.maj = buf->stx_rdev_major; + p->rdev.min = buf->stx_rdev_minor; + p->dev.maj = buf->stx_dev_major; + p->dev.min = buf->stx_dev_minor; +} + +int stat_file(const char *path, struct hostfs_stat *p, int fd) +{ + struct statx buf; + int flags = AT_SYMLINK_NOFOLLOW; + + if (fd >= 0) { + flags |= AT_EMPTY_PATH; + path = ""; + } + + if ((statx(fd, path, flags, STATX_BASIC_STATS | STATX_BTIME, &buf)) < 0) + return -errno; + + statx_to_hostfs(&buf, p); + return 0; +} + +int access_file(char *path, int r, int w, int x) +{ + int mode = 0; + + if (r) + mode = R_OK; + if (w) + mode |= W_OK; + if (x) + mode |= X_OK; + if (access(path, mode) != 0) + return -errno; + else return 0; +} + +int open_file(char *path, int r, int w, int append) +{ + int mode = 0, fd; + + if (r && !w) + mode = O_RDONLY; + else if (!r && w) + mode = O_WRONLY; + else if (r && w) + mode = O_RDWR; + else panic("Impossible mode in open_file"); + + if (append) + mode |= O_APPEND; + fd = open64(path, mode); + if (fd < 0) + return -errno; + else return fd; +} + +void *open_dir(char *path, int *err_out) +{ + DIR *dir; + + dir = opendir(path); + *err_out = errno; + + return dir; +} + +void seek_dir(void *stream, unsigned long long pos) +{ + DIR *dir = stream; + + seekdir(dir, pos); +} + +char *read_dir(void *stream, unsigned long long *pos_out, + unsigned long long *ino_out, int *len_out, + unsigned int *type_out) +{ + DIR *dir = stream; + struct dirent *ent; + + ent = readdir(dir); + if (ent == NULL) + return NULL; + *len_out = strlen(ent->d_name); + *ino_out = ent->d_ino; + *type_out = ent->d_type; + *pos_out = ent->d_off; + return ent->d_name; +} + +int read_file(int fd, unsigned long long *offset, char *buf, int len) +{ + int n; + + n = pread64(fd, buf, len, *offset); + if (n < 0) + return -errno; + *offset += n; + return n; +} + +int write_file(int fd, unsigned long long *offset, const char *buf, int len) +{ + int n; + + n = pwrite64(fd, buf, len, *offset); + if (n < 0) + return -errno; + *offset += n; + return n; +} + +int lseek_file(int fd, long long offset, int whence) +{ + int ret; + + ret = lseek64(fd, offset, whence); + if (ret < 0) + return -errno; + return 0; +} + +int fsync_file(int fd, int datasync) +{ + int ret; + if (datasync) + ret = fdatasync(fd); + else + ret = fsync(fd); + + if (ret < 0) + return -errno; + return 0; +} + +int replace_file(int oldfd, int fd) +{ + return dup2(oldfd, fd); +} + +void close_file(void *stream) +{ + close(*((int *) stream)); +} + +void close_dir(void *stream) +{ + closedir(stream); +} + +int file_create(char *name, int mode) +{ + int fd; + + fd = open64(name, O_CREAT | O_RDWR, mode); + if (fd < 0) + return -errno; + return fd; +} + +int set_attr(const char *file, struct hostfs_iattr *attrs, int fd) +{ + struct hostfs_stat st; + struct timeval times[2]; + int err, ma; + + if (attrs->ia_valid & HOSTFS_ATTR_MODE) { + if (fd >= 0) { + if (fchmod(fd, attrs->ia_mode) != 0) + return -errno; + } else if (chmod(file, attrs->ia_mode) != 0) { + return -errno; + } + } + if (attrs->ia_valid & HOSTFS_ATTR_UID) { + if (fd >= 0) { + if (fchown(fd, attrs->ia_uid, -1)) + return -errno; + } else if (chown(file, attrs->ia_uid, -1)) { + return -errno; + } + } + if (attrs->ia_valid & HOSTFS_ATTR_GID) { + if (fd >= 0) { + if (fchown(fd, -1, attrs->ia_gid)) + return -errno; + } else if (chown(file, -1, attrs->ia_gid)) { + return -errno; + } + } + if (attrs->ia_valid & HOSTFS_ATTR_SIZE) { + if (fd >= 0) { + if (ftruncate(fd, attrs->ia_size)) + return -errno; + } else if (truncate(file, attrs->ia_size)) { + return -errno; + } + } + + /* + * Update accessed and/or modified time, in two parts: first set + * times according to the changes to perform, and then call futimes() + * or utimes() to apply them. + */ + ma = (HOSTFS_ATTR_ATIME_SET | HOSTFS_ATTR_MTIME_SET); + if (attrs->ia_valid & ma) { + err = stat_file(file, &st, fd); + if (err != 0) + return err; + + times[0].tv_sec = st.atime.tv_sec; + times[0].tv_usec = st.atime.tv_nsec / 1000; + times[1].tv_sec = st.mtime.tv_sec; + times[1].tv_usec = st.mtime.tv_nsec / 1000; + + if (attrs->ia_valid & HOSTFS_ATTR_ATIME_SET) { + times[0].tv_sec = attrs->ia_atime.tv_sec; + times[0].tv_usec = attrs->ia_atime.tv_nsec / 1000; + } + if (attrs->ia_valid & HOSTFS_ATTR_MTIME_SET) { + times[1].tv_sec = attrs->ia_mtime.tv_sec; + times[1].tv_usec = attrs->ia_mtime.tv_nsec / 1000; + } + + if (fd >= 0) { + if (futimes(fd, times) != 0) + return -errno; + } else if (utimes(file, times) != 0) { + return -errno; + } + } + + /* Note: ctime is not handled */ + if (attrs->ia_valid & (HOSTFS_ATTR_ATIME | HOSTFS_ATTR_MTIME)) { + err = stat_file(file, &st, fd); + attrs->ia_atime = st.atime; + attrs->ia_mtime = st.mtime; + if (err != 0) + return err; + } + return 0; +} + +int make_symlink(const char *from, const char *to) +{ + int err; + + err = symlink(to, from); + if (err) + return -errno; + return 0; +} + +int unlink_file(const char *file) +{ + int err; + + err = unlink(file); + if (err) + return -errno; + return 0; +} + +int do_mkdir(const char *file, int mode) +{ + int err; + + err = mkdir(file, mode); + if (err) + return -errno; + return 0; +} + +int hostfs_do_rmdir(const char *file) +{ + int err; + + err = rmdir(file); + if (err) + return -errno; + return 0; +} + +int do_mknod(const char *file, int mode, unsigned int major, unsigned int minor) +{ + int err; + + err = mknod(file, mode, os_makedev(major, minor)); + if (err) + return -errno; + return 0; +} + +int link_file(const char *to, const char *from) +{ + int err; + + err = link(to, from); + if (err) + return -errno; + return 0; +} + +int hostfs_do_readlink(char *file, char *buf, int size) +{ + int n; + + n = readlink(file, buf, size); + if (n < 0) + return -errno; + if (n < size) + buf[n] = '\0'; + return n; +} + +int rename_file(char *from, char *to) +{ + int err; + + err = rename(from, to); + if (err < 0) + return -errno; + return 0; +} + +int rename2_file(char *from, char *to, unsigned int flags) +{ + int err; + +#ifndef SYS_renameat2 +# ifdef __x86_64__ +# define SYS_renameat2 316 +# endif +# ifdef __i386__ +# define SYS_renameat2 353 +# endif +#endif + +#ifdef SYS_renameat2 + err = syscall(SYS_renameat2, AT_FDCWD, from, AT_FDCWD, to, flags); + if (err < 0) { + if (errno != ENOSYS) + return -errno; + else + return -EINVAL; + } + return 0; +#else + return -EINVAL; +#endif +} + +int do_statfs(char *root, long *bsize_out, long long *blocks_out, + long long *bfree_out, long long *bavail_out, + long long *files_out, long long *ffree_out, + void *fsid_out, int fsid_size, long *namelen_out) +{ + struct statfs64 buf; + int err; + + err = statfs64(root, &buf); + if (err < 0) + return -errno; + + *bsize_out = buf.f_bsize; + *blocks_out = buf.f_blocks; + *bfree_out = buf.f_bfree; + *bavail_out = buf.f_bavail; + *files_out = buf.f_files; + *ffree_out = buf.f_ffree; + memcpy(fsid_out, &buf.f_fsid, + sizeof(buf.f_fsid) > fsid_size ? fsid_size : + sizeof(buf.f_fsid)); + *namelen_out = buf.f_namelen; + + return 0; +} diff --git a/fs/hostfs/hostfs_user_exp.c b/fs/hostfs/hostfs_user_exp.c new file mode 100644 index 000000000..250c91c55 --- /dev/null +++ b/fs/hostfs/hostfs_user_exp.c @@ -0,0 +1,28 @@ +#include <linux/module.h> +#include "hostfs.h" + +EXPORT_SYMBOL_GPL(stat_file); +EXPORT_SYMBOL_GPL(access_file); +EXPORT_SYMBOL_GPL(open_file); +EXPORT_SYMBOL_GPL(open_dir); +EXPORT_SYMBOL_GPL(seek_dir); +EXPORT_SYMBOL_GPL(read_dir); +EXPORT_SYMBOL_GPL(read_file); +EXPORT_SYMBOL_GPL(write_file); +EXPORT_SYMBOL_GPL(lseek_file); +EXPORT_SYMBOL_GPL(fsync_file); +EXPORT_SYMBOL_GPL(replace_file); +EXPORT_SYMBOL_GPL(close_file); +EXPORT_SYMBOL_GPL(close_dir); +EXPORT_SYMBOL_GPL(file_create); +EXPORT_SYMBOL_GPL(set_attr); +EXPORT_SYMBOL_GPL(make_symlink); +EXPORT_SYMBOL_GPL(unlink_file); +EXPORT_SYMBOL_GPL(do_mkdir); +EXPORT_SYMBOL_GPL(hostfs_do_rmdir); +EXPORT_SYMBOL_GPL(do_mknod); +EXPORT_SYMBOL_GPL(link_file); +EXPORT_SYMBOL_GPL(hostfs_do_readlink); +EXPORT_SYMBOL_GPL(rename_file); +EXPORT_SYMBOL_GPL(rename2_file); +EXPORT_SYMBOL_GPL(do_statfs); |