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
ext2_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)21 long 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);
78 setflags_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);
103 setversion_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
ext2_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)162 long 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