1 /*
2 * linux/fs/ext2/ioctl.c
3 *
4 * Copyright (C) 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 */
9
10 #include "ext2.h"
11 #include <linux/capability.h>
12 #include <linux/time.h>
13 #include <linux/sched.h>
14 #include <linux/compat.h>
15 #include <linux/mount.h>
16 #include <asm/current.h>
17 #include <asm/uaccess.h>
18
19
ext2_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)20 long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
21 {
22 struct inode *inode = filp->f_dentry->d_inode;
23 struct ext2_inode_info *ei = EXT2_I(inode);
24 unsigned int flags;
25 unsigned short rsv_window_size;
26 int ret;
27
28 ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
29
30 switch (cmd) {
31 case EXT2_IOC_GETFLAGS:
32 ext2_get_inode_flags(ei);
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 mutex_lock(&inode->i_mutex);
55 /* Is it quota file? Do not allow user to mess with it */
56 if (IS_NOQUOTA(inode)) {
57 mutex_unlock(&inode->i_mutex);
58 ret = -EPERM;
59 goto setflags_out;
60 }
61 oldflags = ei->i_flags;
62
63 /*
64 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
65 * the relevant capability.
66 *
67 * This test looks nicer. Thanks to Pauline Middelink
68 */
69 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
70 if (!capable(CAP_LINUX_IMMUTABLE)) {
71 mutex_unlock(&inode->i_mutex);
72 ret = -EPERM;
73 goto setflags_out;
74 }
75 }
76
77 flags = flags & EXT2_FL_USER_MODIFIABLE;
78 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
79 ei->i_flags = flags;
80
81 ext2_set_inode_flags(inode);
82 inode->i_ctime = CURRENT_TIME_SEC;
83 mutex_unlock(&inode->i_mutex);
84
85 mark_inode_dirty(inode);
86 setflags_out:
87 mnt_drop_write_file(filp);
88 return ret;
89 }
90 case EXT2_IOC_GETVERSION:
91 return put_user(inode->i_generation, (int __user *) arg);
92 case EXT2_IOC_SETVERSION: {
93 __u32 generation;
94
95 if (!inode_owner_or_capable(inode))
96 return -EPERM;
97 ret = mnt_want_write_file(filp);
98 if (ret)
99 return ret;
100 if (get_user(generation, (int __user *) arg)) {
101 ret = -EFAULT;
102 goto setversion_out;
103 }
104
105 mutex_lock(&inode->i_mutex);
106 inode->i_ctime = CURRENT_TIME_SEC;
107 inode->i_generation = generation;
108 mutex_unlock(&inode->i_mutex);
109
110 mark_inode_dirty(inode);
111 setversion_out:
112 mnt_drop_write_file(filp);
113 return ret;
114 }
115 case EXT2_IOC_GETRSVSZ:
116 if (test_opt(inode->i_sb, RESERVATION)
117 && S_ISREG(inode->i_mode)
118 && ei->i_block_alloc_info) {
119 rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
120 return put_user(rsv_window_size, (int __user *)arg);
121 }
122 return -ENOTTY;
123 case EXT2_IOC_SETRSVSZ: {
124
125 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
126 return -ENOTTY;
127
128 if (!inode_owner_or_capable(inode))
129 return -EACCES;
130
131 if (get_user(rsv_window_size, (int __user *)arg))
132 return -EFAULT;
133
134 ret = mnt_want_write_file(filp);
135 if (ret)
136 return ret;
137
138 if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
139 rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
140
141 /*
142 * need to allocate reservation structure for this inode
143 * before set the window size
144 */
145 /*
146 * XXX What lock should protect the rsv_goal_size?
147 * Accessed in ext2_get_block only. ext3 uses i_truncate.
148 */
149 mutex_lock(&ei->truncate_mutex);
150 if (!ei->i_block_alloc_info)
151 ext2_init_block_alloc_info(inode);
152
153 if (ei->i_block_alloc_info){
154 struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
155 rsv->rsv_goal_size = rsv_window_size;
156 }
157 mutex_unlock(&ei->truncate_mutex);
158 mnt_drop_write_file(filp);
159 return 0;
160 }
161 default:
162 return -ENOTTY;
163 }
164 }
165
166 #ifdef CONFIG_COMPAT
ext2_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)167 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
168 {
169 /* These are just misnamed, they actually get/put from/to user an int */
170 switch (cmd) {
171 case EXT2_IOC32_GETFLAGS:
172 cmd = EXT2_IOC_GETFLAGS;
173 break;
174 case EXT2_IOC32_SETFLAGS:
175 cmd = EXT2_IOC_SETFLAGS;
176 break;
177 case EXT2_IOC32_GETVERSION:
178 cmd = EXT2_IOC_GETVERSION;
179 break;
180 case EXT2_IOC32_SETVERSION:
181 cmd = EXT2_IOC_SETVERSION;
182 break;
183 default:
184 return -ENOIOCTLCMD;
185 }
186 return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
187 }
188 #endif
189