xref: /kernel/linux/linux-5.10/fs/ext2/ioctl.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext2/ioctl.c
4 *
5 * Copyright (C) 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 */
10
11#include "ext2.h"
12#include <linux/capability.h>
13#include <linux/time.h>
14#include <linux/sched.h>
15#include <linux/compat.h>
16#include <linux/mount.h>
17#include <asm/current.h>
18#include <linux/uaccess.h>
19
20
21long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
22{
23	struct inode *inode = file_inode(filp);
24	struct ext2_inode_info *ei = EXT2_I(inode);
25	unsigned int flags;
26	unsigned short rsv_window_size;
27	int ret;
28
29	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
30
31	switch (cmd) {
32	case EXT2_IOC_GETFLAGS:
33		flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
34		return put_user(flags, (int __user *) arg);
35	case EXT2_IOC_SETFLAGS: {
36		unsigned int oldflags;
37
38		ret = mnt_want_write_file(filp);
39		if (ret)
40			return ret;
41
42		if (!inode_owner_or_capable(inode)) {
43			ret = -EACCES;
44			goto setflags_out;
45		}
46
47		if (get_user(flags, (int __user *) arg)) {
48			ret = -EFAULT;
49			goto setflags_out;
50		}
51
52		flags = ext2_mask_flags(inode->i_mode, flags);
53
54		inode_lock(inode);
55		/* Is it quota file? Do not allow user to mess with it */
56		if (IS_NOQUOTA(inode)) {
57			inode_unlock(inode);
58			ret = -EPERM;
59			goto setflags_out;
60		}
61		oldflags = ei->i_flags;
62
63		ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
64		if (ret) {
65			inode_unlock(inode);
66			goto setflags_out;
67		}
68
69		flags = flags & EXT2_FL_USER_MODIFIABLE;
70		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
71		ei->i_flags = flags;
72
73		ext2_set_inode_flags(inode);
74		inode->i_ctime = current_time(inode);
75		inode_unlock(inode);
76
77		mark_inode_dirty(inode);
78setflags_out:
79		mnt_drop_write_file(filp);
80		return ret;
81	}
82	case EXT2_IOC_GETVERSION:
83		return put_user(inode->i_generation, (int __user *) arg);
84	case EXT2_IOC_SETVERSION: {
85		__u32 generation;
86
87		if (!inode_owner_or_capable(inode))
88			return -EPERM;
89		ret = mnt_want_write_file(filp);
90		if (ret)
91			return ret;
92		if (get_user(generation, (int __user *) arg)) {
93			ret = -EFAULT;
94			goto setversion_out;
95		}
96
97		inode_lock(inode);
98		inode->i_ctime = current_time(inode);
99		inode->i_generation = generation;
100		inode_unlock(inode);
101
102		mark_inode_dirty(inode);
103setversion_out:
104		mnt_drop_write_file(filp);
105		return ret;
106	}
107	case EXT2_IOC_GETRSVSZ:
108		if (test_opt(inode->i_sb, RESERVATION)
109			&& S_ISREG(inode->i_mode)
110			&& ei->i_block_alloc_info) {
111			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
112			return put_user(rsv_window_size, (int __user *)arg);
113		}
114		return -ENOTTY;
115	case EXT2_IOC_SETRSVSZ: {
116
117		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
118			return -ENOTTY;
119
120		if (!inode_owner_or_capable(inode))
121			return -EACCES;
122
123		if (get_user(rsv_window_size, (int __user *)arg))
124			return -EFAULT;
125
126		ret = mnt_want_write_file(filp);
127		if (ret)
128			return ret;
129
130		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
131			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
132
133		/*
134		 * need to allocate reservation structure for this inode
135		 * before set the window size
136		 */
137		/*
138		 * XXX What lock should protect the rsv_goal_size?
139		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
140		 */
141		mutex_lock(&ei->truncate_mutex);
142		if (!ei->i_block_alloc_info)
143			ext2_init_block_alloc_info(inode);
144
145		if (ei->i_block_alloc_info){
146			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
147			rsv->rsv_goal_size = rsv_window_size;
148		} else {
149			ret = -ENOMEM;
150		}
151
152		mutex_unlock(&ei->truncate_mutex);
153		mnt_drop_write_file(filp);
154		return ret;
155	}
156	default:
157		return -ENOTTY;
158	}
159}
160
161#ifdef CONFIG_COMPAT
162long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
163{
164	/* These are just misnamed, they actually get/put from/to user an int */
165	switch (cmd) {
166	case EXT2_IOC32_GETFLAGS:
167		cmd = EXT2_IOC_GETFLAGS;
168		break;
169	case EXT2_IOC32_SETFLAGS:
170		cmd = EXT2_IOC_SETFLAGS;
171		break;
172	case EXT2_IOC32_GETVERSION:
173		cmd = EXT2_IOC_GETVERSION;
174		break;
175	case EXT2_IOC32_SETVERSION:
176		cmd = EXT2_IOC_SETVERSION;
177		break;
178	default:
179		return -ENOIOCTLCMD;
180	}
181	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
182}
183#endif
184