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![Christian Brauner](/assets/img/avatar_default.png)
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b
("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
160 lines
3.7 KiB
C
160 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext2/ioctl.c
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*
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* Copyright (C) 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*/
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#include "ext2.h"
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#include <linux/capability.h>
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#include <linux/time.h>
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#include <linux/sched.h>
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#include <linux/compat.h>
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#include <linux/mount.h>
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#include <asm/current.h>
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#include <linux/uaccess.h>
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#include <linux/fileattr.h>
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int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
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{
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struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
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fileattr_fill_flags(fa, ei->i_flags & EXT2_FL_USER_VISIBLE);
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return 0;
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}
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int ext2_fileattr_set(struct mnt_idmap *idmap,
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struct dentry *dentry, struct fileattr *fa)
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{
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struct inode *inode = d_inode(dentry);
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struct ext2_inode_info *ei = EXT2_I(inode);
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if (fileattr_has_fsx(fa))
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return -EOPNOTSUPP;
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/* Is it quota file? Do not allow user to mess with it */
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if (IS_NOQUOTA(inode))
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return -EPERM;
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ei->i_flags = (ei->i_flags & ~EXT2_FL_USER_MODIFIABLE) |
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(fa->flags & EXT2_FL_USER_MODIFIABLE);
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ext2_set_inode_flags(inode);
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inode->i_ctime = current_time(inode);
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mark_inode_dirty(inode);
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return 0;
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}
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long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
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struct inode *inode = file_inode(filp);
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struct ext2_inode_info *ei = EXT2_I(inode);
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unsigned short rsv_window_size;
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int ret;
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ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
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switch (cmd) {
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case EXT2_IOC_GETVERSION:
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return put_user(inode->i_generation, (int __user *) arg);
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case EXT2_IOC_SETVERSION: {
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__u32 generation;
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if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
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return -EPERM;
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ret = mnt_want_write_file(filp);
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if (ret)
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return ret;
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if (get_user(generation, (int __user *) arg)) {
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ret = -EFAULT;
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goto setversion_out;
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}
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inode_lock(inode);
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inode->i_ctime = current_time(inode);
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inode->i_generation = generation;
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inode_unlock(inode);
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mark_inode_dirty(inode);
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setversion_out:
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mnt_drop_write_file(filp);
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return ret;
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}
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case EXT2_IOC_GETRSVSZ:
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if (test_opt(inode->i_sb, RESERVATION)
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&& S_ISREG(inode->i_mode)
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&& ei->i_block_alloc_info) {
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rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
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return put_user(rsv_window_size, (int __user *)arg);
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}
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return -ENOTTY;
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case EXT2_IOC_SETRSVSZ: {
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if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
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return -ENOTTY;
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if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
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return -EACCES;
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if (get_user(rsv_window_size, (int __user *)arg))
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return -EFAULT;
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ret = mnt_want_write_file(filp);
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if (ret)
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return ret;
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if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
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rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
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/*
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* need to allocate reservation structure for this inode
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* before set the window size
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*/
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/*
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* XXX What lock should protect the rsv_goal_size?
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* Accessed in ext2_get_block only. ext3 uses i_truncate.
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*/
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mutex_lock(&ei->truncate_mutex);
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if (!ei->i_block_alloc_info)
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ext2_init_block_alloc_info(inode);
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if (ei->i_block_alloc_info){
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struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
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rsv->rsv_goal_size = rsv_window_size;
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} else {
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ret = -ENOMEM;
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}
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mutex_unlock(&ei->truncate_mutex);
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mnt_drop_write_file(filp);
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return ret;
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}
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default:
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return -ENOTTY;
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}
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}
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#ifdef CONFIG_COMPAT
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long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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/* These are just misnamed, they actually get/put from/to user an int */
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switch (cmd) {
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case EXT2_IOC32_GETVERSION:
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cmd = EXT2_IOC_GETVERSION;
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break;
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case EXT2_IOC32_SETVERSION:
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cmd = EXT2_IOC_SETVERSION;
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break;
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default:
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return -ENOIOCTLCMD;
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}
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return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
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}
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#endif
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