Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
[firefly-linux-kernel-4.4.55.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 = file_inode(filp);
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
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