![Christoph Hellwig](/assets/img/avatar_default.png)
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1058 lines
22 KiB
C
1058 lines
22 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*
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* Ported the filesystem routines to 2.5.
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* 2003-02-10 Petr Baudis <pasky@ucw.cz>
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*/
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/statfs.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#include <linux/mount.h>
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#include "hostfs.h"
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#include "init.h"
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#include "kern.h"
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struct hostfs_inode_info {
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char *host_filename;
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int fd;
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fmode_t mode;
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struct inode vfs_inode;
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};
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static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
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{
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return list_entry(inode, struct hostfs_inode_info, vfs_inode);
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}
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#define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode)
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static int hostfs_d_delete(struct dentry *dentry)
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{
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return 1;
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}
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static const struct dentry_operations hostfs_dentry_ops = {
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.d_delete = hostfs_d_delete,
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};
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/* Changed in hostfs_args before the kernel starts running */
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static char *root_ino = "";
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static int append = 0;
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#define HOSTFS_SUPER_MAGIC 0x00c0ffee
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static const struct inode_operations hostfs_iops;
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static const struct inode_operations hostfs_dir_iops;
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static const struct address_space_operations hostfs_link_aops;
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#ifndef MODULE
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static int __init hostfs_args(char *options, int *add)
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{
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char *ptr;
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ptr = strchr(options, ',');
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if (ptr != NULL)
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*ptr++ = '\0';
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if (*options != '\0')
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root_ino = options;
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options = ptr;
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while (options) {
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ptr = strchr(options, ',');
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if (ptr != NULL)
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*ptr++ = '\0';
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if (*options != '\0') {
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if (!strcmp(options, "append"))
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append = 1;
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else printf("hostfs_args - unsupported option - %s\n",
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options);
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}
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options = ptr;
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}
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return 0;
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}
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__uml_setup("hostfs=", hostfs_args,
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"hostfs=<root dir>,<flags>,...\n"
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" This is used to set hostfs parameters. The root directory argument\n"
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" is used to confine all hostfs mounts to within the specified directory\n"
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" tree on the host. If this isn't specified, then a user inside UML can\n"
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" mount anything on the host that's accessible to the user that's running\n"
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" it.\n"
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" The only flag currently supported is 'append', which specifies that all\n"
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" files opened by hostfs will be opened in append mode.\n\n"
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);
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#endif
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static char *dentry_name(struct dentry *dentry, int extra)
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{
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struct dentry *parent;
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char *root, *name;
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int len;
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len = 0;
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parent = dentry;
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while (parent->d_parent != parent) {
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len += parent->d_name.len + 1;
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parent = parent->d_parent;
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}
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root = HOSTFS_I(parent->d_inode)->host_filename;
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len += strlen(root);
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name = kmalloc(len + extra + 1, GFP_KERNEL);
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if (name == NULL)
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return NULL;
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name[len] = '\0';
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parent = dentry;
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while (parent->d_parent != parent) {
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len -= parent->d_name.len + 1;
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name[len] = '/';
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strncpy(&name[len + 1], parent->d_name.name,
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parent->d_name.len);
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parent = parent->d_parent;
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}
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strncpy(name, root, strlen(root));
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return name;
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}
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static char *inode_name(struct inode *ino, int extra)
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{
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struct dentry *dentry;
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dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias);
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return dentry_name(dentry, extra);
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}
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static int read_name(struct inode *ino, char *name)
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{
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/*
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* The non-int inode fields are copied into ints by stat_file and
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* then copied into the inode because passing the actual pointers
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* in and having them treated as int * breaks on big-endian machines
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*/
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int err;
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int i_mode, i_nlink, i_blksize;
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unsigned long long i_size;
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unsigned long long i_ino;
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unsigned long long i_blocks;
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err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid,
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&ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime,
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&ino->i_ctime, &i_blksize, &i_blocks, -1);
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if (err)
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return err;
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ino->i_ino = i_ino;
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ino->i_mode = i_mode;
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ino->i_nlink = i_nlink;
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ino->i_size = i_size;
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ino->i_blocks = i_blocks;
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return 0;
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}
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static char *follow_link(char *link)
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{
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int len, n;
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char *name, *resolved, *end;
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len = 64;
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while (1) {
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n = -ENOMEM;
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name = kmalloc(len, GFP_KERNEL);
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if (name == NULL)
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goto out;
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n = hostfs_do_readlink(link, name, len);
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if (n < len)
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break;
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len *= 2;
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kfree(name);
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}
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if (n < 0)
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goto out_free;
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if (*name == '/')
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return name;
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end = strrchr(link, '/');
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if (end == NULL)
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return name;
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*(end + 1) = '\0';
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len = strlen(link) + strlen(name) + 1;
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resolved = kmalloc(len, GFP_KERNEL);
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if (resolved == NULL) {
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n = -ENOMEM;
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goto out_free;
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}
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sprintf(resolved, "%s%s", link, name);
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kfree(name);
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kfree(link);
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return resolved;
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out_free:
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kfree(name);
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out:
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return ERR_PTR(n);
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}
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static int hostfs_read_inode(struct inode *ino)
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{
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char *name;
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int err = 0;
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/*
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* Unfortunately, we are called from iget() when we don't have a dentry
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* allocated yet.
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*/
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if (list_empty(&ino->i_dentry))
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goto out;
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err = -ENOMEM;
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name = inode_name(ino, 0);
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if (name == NULL)
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goto out;
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if (file_type(name, NULL, NULL) == OS_TYPE_SYMLINK) {
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name = follow_link(name);
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if (IS_ERR(name)) {
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err = PTR_ERR(name);
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goto out;
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}
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}
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err = read_name(ino, name);
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kfree(name);
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out:
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return err;
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}
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static struct inode *hostfs_iget(struct super_block *sb)
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{
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struct inode *inode;
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long ret;
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inode = iget_locked(sb, 0);
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if (!inode)
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return ERR_PTR(-ENOMEM);
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if (inode->i_state & I_NEW) {
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ret = hostfs_read_inode(inode);
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if (ret < 0) {
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iget_failed(inode);
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return ERR_PTR(ret);
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}
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unlock_new_inode(inode);
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}
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return inode;
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}
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int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
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{
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/*
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* do_statfs uses struct statfs64 internally, but the linux kernel
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* struct statfs still has 32-bit versions for most of these fields,
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* so we convert them here
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*/
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int err;
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long long f_blocks;
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long long f_bfree;
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long long f_bavail;
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long long f_files;
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long long f_ffree;
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err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename,
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&sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
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&f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
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&sf->f_namelen, sf->f_spare);
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if (err)
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return err;
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sf->f_blocks = f_blocks;
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sf->f_bfree = f_bfree;
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sf->f_bavail = f_bavail;
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sf->f_files = f_files;
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sf->f_ffree = f_ffree;
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sf->f_type = HOSTFS_SUPER_MAGIC;
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return 0;
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}
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static struct inode *hostfs_alloc_inode(struct super_block *sb)
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{
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struct hostfs_inode_info *hi;
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hi = kmalloc(sizeof(*hi), GFP_KERNEL);
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if (hi == NULL)
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return NULL;
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*hi = ((struct hostfs_inode_info) { .host_filename = NULL,
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.fd = -1,
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.mode = 0 });
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inode_init_once(&hi->vfs_inode);
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return &hi->vfs_inode;
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}
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static void hostfs_delete_inode(struct inode *inode)
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{
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truncate_inode_pages(&inode->i_data, 0);
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if (HOSTFS_I(inode)->fd != -1) {
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close_file(&HOSTFS_I(inode)->fd);
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HOSTFS_I(inode)->fd = -1;
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}
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clear_inode(inode);
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}
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static void hostfs_destroy_inode(struct inode *inode)
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{
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kfree(HOSTFS_I(inode)->host_filename);
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/*
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* XXX: This should not happen, probably. The check is here for
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* additional safety.
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*/
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if (HOSTFS_I(inode)->fd != -1) {
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close_file(&HOSTFS_I(inode)->fd);
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printk(KERN_DEBUG "Closing host fd in .destroy_inode\n");
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}
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kfree(HOSTFS_I(inode));
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}
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static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
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{
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struct inode *root = vfs->mnt_sb->s_root->d_inode;
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const char *root_path = HOSTFS_I(root)->host_filename;
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size_t offset = strlen(root_ino) + 1;
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if (strlen(root_path) > offset)
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seq_printf(seq, ",%s", root_path + offset);
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return 0;
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}
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static const struct super_operations hostfs_sbops = {
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.alloc_inode = hostfs_alloc_inode,
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.drop_inode = generic_delete_inode,
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.delete_inode = hostfs_delete_inode,
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.destroy_inode = hostfs_destroy_inode,
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.statfs = hostfs_statfs,
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.show_options = hostfs_show_options,
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};
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int hostfs_readdir(struct file *file, void *ent, filldir_t filldir)
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{
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void *dir;
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char *name;
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unsigned long long next, ino;
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int error, len;
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name = dentry_name(file->f_path.dentry, 0);
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if (name == NULL)
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return -ENOMEM;
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dir = open_dir(name, &error);
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kfree(name);
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if (dir == NULL)
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return -error;
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next = file->f_pos;
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while ((name = read_dir(dir, &next, &ino, &len)) != NULL) {
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error = (*filldir)(ent, name, len, file->f_pos,
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ino, DT_UNKNOWN);
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if (error) break;
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file->f_pos = next;
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}
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close_dir(dir);
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return 0;
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}
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int hostfs_file_open(struct inode *ino, struct file *file)
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{
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char *name;
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fmode_t mode = 0;
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int r = 0, w = 0, fd;
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mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
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if ((mode & HOSTFS_I(ino)->mode) == mode)
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return 0;
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/*
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* The file may already have been opened, but with the wrong access,
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* so this resets things and reopens the file with the new access.
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*/
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if (HOSTFS_I(ino)->fd != -1) {
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close_file(&HOSTFS_I(ino)->fd);
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HOSTFS_I(ino)->fd = -1;
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}
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HOSTFS_I(ino)->mode |= mode;
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if (HOSTFS_I(ino)->mode & FMODE_READ)
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r = 1;
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if (HOSTFS_I(ino)->mode & FMODE_WRITE)
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w = 1;
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if (w)
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r = 1;
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name = dentry_name(file->f_path.dentry, 0);
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if (name == NULL)
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return -ENOMEM;
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fd = open_file(name, r, w, append);
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kfree(name);
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if (fd < 0)
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return fd;
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FILE_HOSTFS_I(file)->fd = fd;
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return 0;
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}
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int hostfs_fsync(struct file *file, int datasync)
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{
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return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync);
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}
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static const struct file_operations hostfs_file_fops = {
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.llseek = generic_file_llseek,
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.read = do_sync_read,
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.splice_read = generic_file_splice_read,
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.aio_read = generic_file_aio_read,
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.aio_write = generic_file_aio_write,
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.write = do_sync_write,
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.mmap = generic_file_mmap,
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.open = hostfs_file_open,
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.release = NULL,
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.fsync = hostfs_fsync,
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};
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static const struct file_operations hostfs_dir_fops = {
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.llseek = generic_file_llseek,
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.readdir = hostfs_readdir,
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.read = generic_read_dir,
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};
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|
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int hostfs_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct address_space *mapping = page->mapping;
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struct inode *inode = mapping->host;
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char *buffer;
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unsigned long long base;
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int count = PAGE_CACHE_SIZE;
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int end_index = inode->i_size >> PAGE_CACHE_SHIFT;
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int err;
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|
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if (page->index >= end_index)
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count = inode->i_size & (PAGE_CACHE_SIZE-1);
|
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|
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buffer = kmap(page);
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base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT;
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err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
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if (err != count) {
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ClearPageUptodate(page);
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goto out;
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}
|
|
|
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if (base > inode->i_size)
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inode->i_size = base;
|
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|
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if (PageError(page))
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ClearPageError(page);
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err = 0;
|
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|
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out:
|
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kunmap(page);
|
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|
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unlock_page(page);
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return err;
|
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}
|
|
|
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int hostfs_readpage(struct file *file, struct page *page)
|
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{
|
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char *buffer;
|
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long long start;
|
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int err = 0;
|
|
|
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start = (long long) page->index << PAGE_CACHE_SHIFT;
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buffer = kmap(page);
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err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
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PAGE_CACHE_SIZE);
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if (err < 0)
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goto out;
|
|
|
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memset(&buffer[err], 0, PAGE_CACHE_SIZE - err);
|
|
|
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flush_dcache_page(page);
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SetPageUptodate(page);
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if (PageError(page)) ClearPageError(page);
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err = 0;
|
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out:
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kunmap(page);
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unlock_page(page);
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return err;
|
|
}
|
|
|
|
int hostfs_write_begin(struct file *file, struct address_space *mapping,
|
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loff_t pos, unsigned len, unsigned flags,
|
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struct page **pagep, void **fsdata)
|
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{
|
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pgoff_t index = pos >> PAGE_CACHE_SHIFT;
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|
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*pagep = grab_cache_page_write_begin(mapping, index, flags);
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if (!*pagep)
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return -ENOMEM;
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return 0;
|
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}
|
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|
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int hostfs_write_end(struct file *file, struct address_space *mapping,
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loff_t pos, unsigned len, unsigned copied,
|
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struct page *page, void *fsdata)
|
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{
|
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struct inode *inode = mapping->host;
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void *buffer;
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unsigned from = pos & (PAGE_CACHE_SIZE - 1);
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int err;
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|
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buffer = kmap(page);
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err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied);
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kunmap(page);
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|
|
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if (!PageUptodate(page) && err == PAGE_CACHE_SIZE)
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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))
|
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inode->i_size = pos;
|
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unlock_page(page);
|
|
page_cache_release(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 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;
|
|
|
|
inode = hostfs_iget(dir->i_sb);
|
|
if (IS_ERR(inode)) {
|
|
error = PTR_ERR(inode);
|
|
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;
|
|
|
|
inode = hostfs_iget(ino->i_sb);
|
|
if (IS_ERR(inode)) {
|
|
err = PTR_ERR(inode);
|
|
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;
|
|
|
|
inode = hostfs_iget(dir->i_sb);
|
|
if (IS_ERR(inode)) {
|
|
err = PTR_ERR(inode);
|
|
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)
|
|
{
|
|
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;
|
|
|
|
int fd = HOSTFS_I(dentry->d_inode)->fd;
|
|
|
|
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, fd);
|
|
kfree(name);
|
|
if (err)
|
|
return err;
|
|
|
|
return inode_setattr(dentry->d_inode, attr);
|
|
}
|
|
|
|
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,
|
|
};
|
|
|
|
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,
|
|
};
|
|
|
|
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 = hostfs_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;
|
|
sb->s_maxbytes = MAX_LFS_FILESIZE;
|
|
|
|
/* 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 = hostfs_iget(sb);
|
|
if (IS_ERR(root_inode)) {
|
|
err = PTR_ERR(root_inode);
|
|
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 = hostfs_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");
|