userns: rename is_owner_or_cap to inode_owner_or_capable
[linux-2.6.git] / fs / ext2 / ioctl.c
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
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(filp->f_path.mnt);
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                 mutex_unlock(&inode->i_mutex);
81
82                 ext2_set_inode_flags(inode);
83                 inode->i_ctime = CURRENT_TIME_SEC;
84                 mark_inode_dirty(inode);
85 setflags_out:
86                 mnt_drop_write(filp->f_path.mnt);
87                 return ret;
88         }
89         case EXT2_IOC_GETVERSION:
90                 return put_user(inode->i_generation, (int __user *) arg);
91         case EXT2_IOC_SETVERSION:
92                 if (!inode_owner_or_capable(inode))
93                         return -EPERM;
94                 ret = mnt_want_write(filp->f_path.mnt);
95                 if (ret)
96                         return ret;
97                 if (get_user(inode->i_generation, (int __user *) arg)) {
98                         ret = -EFAULT;
99                 } else {
100                         inode->i_ctime = CURRENT_TIME_SEC;
101                         mark_inode_dirty(inode);
102                 }
103                 mnt_drop_write(filp->f_path.mnt);
104                 return ret;
105         case EXT2_IOC_GETRSVSZ:
106                 if (test_opt(inode->i_sb, RESERVATION)
107                         && S_ISREG(inode->i_mode)
108                         && ei->i_block_alloc_info) {
109                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
110                         return put_user(rsv_window_size, (int __user *)arg);
111                 }
112                 return -ENOTTY;
113         case EXT2_IOC_SETRSVSZ: {
114
115                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
116                         return -ENOTTY;
117
118                 if (!inode_owner_or_capable(inode))
119                         return -EACCES;
120
121                 if (get_user(rsv_window_size, (int __user *)arg))
122                         return -EFAULT;
123
124                 ret = mnt_want_write(filp->f_path.mnt);
125                 if (ret)
126                         return ret;
127
128                 if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
129                         rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
130
131                 /*
132                  * need to allocate reservation structure for this inode
133                  * before set the window size
134                  */
135                 /*
136                  * XXX What lock should protect the rsv_goal_size?
137                  * Accessed in ext2_get_block only.  ext3 uses i_truncate.
138                  */
139                 mutex_lock(&ei->truncate_mutex);
140                 if (!ei->i_block_alloc_info)
141                         ext2_init_block_alloc_info(inode);
142
143                 if (ei->i_block_alloc_info){
144                         struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
145                         rsv->rsv_goal_size = rsv_window_size;
146                 }
147                 mutex_unlock(&ei->truncate_mutex);
148                 mnt_drop_write(filp->f_path.mnt);
149                 return 0;
150         }
151         default:
152                 return -ENOTTY;
153         }
154 }
155
156 #ifdef CONFIG_COMPAT
157 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
158 {
159         /* These are just misnamed, they actually get/put from/to user an int */
160         switch (cmd) {
161         case EXT2_IOC32_GETFLAGS:
162                 cmd = EXT2_IOC_GETFLAGS;
163                 break;
164         case EXT2_IOC32_SETFLAGS:
165                 cmd = EXT2_IOC_SETFLAGS;
166                 break;
167         case EXT2_IOC32_GETVERSION:
168                 cmd = EXT2_IOC_GETVERSION;
169                 break;
170         case EXT2_IOC32_SETVERSION:
171                 cmd = EXT2_IOC_SETVERSION;
172                 break;
173         default:
174                 return -ENOIOCTLCMD;
175         }
176         return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
177 }
178 #endif