500567dd53b6fd9752096c014162927a730748f0
[linux-2.6.git] / fs / ext4 / ioctl.c
1 /*
2  * linux/fs/ext4/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 <linux/fs.h>
11 #include <linux/jbd2.h>
12 #include <linux/capability.h>
13 #include <linux/ext4_fs.h>
14 #include <linux/ext4_jbd2.h>
15 #include <linux/time.h>
16 #include <linux/compat.h>
17 #include <linux/smp_lock.h>
18 #include <asm/uaccess.h>
19
20 int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
21                 unsigned long arg)
22 {
23         struct ext4_inode_info *ei = EXT4_I(inode);
24         unsigned int flags;
25         unsigned short rsv_window_size;
26
27         ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);
28
29         switch (cmd) {
30         case EXT4_IOC_GETFLAGS:
31                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
32                 return put_user(flags, (int __user *) arg);
33         case EXT4_IOC_SETFLAGS: {
34                 handle_t *handle = NULL;
35                 int err;
36                 struct ext4_iloc iloc;
37                 unsigned int oldflags;
38                 unsigned int jflag;
39
40                 if (IS_RDONLY(inode))
41                         return -EROFS;
42
43                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
44                         return -EACCES;
45
46                 if (get_user(flags, (int __user *) arg))
47                         return -EFAULT;
48
49                 if (!S_ISDIR(inode->i_mode))
50                         flags &= ~EXT4_DIRSYNC_FL;
51
52                 mutex_lock(&inode->i_mutex);
53                 oldflags = ei->i_flags;
54
55                 /* The JOURNAL_DATA flag is modifiable only by root */
56                 jflag = flags & EXT4_JOURNAL_DATA_FL;
57
58                 /*
59                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
60                  * the relevant capability.
61                  *
62                  * This test looks nicer. Thanks to Pauline Middelink
63                  */
64                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
65                         if (!capable(CAP_LINUX_IMMUTABLE)) {
66                                 mutex_unlock(&inode->i_mutex);
67                                 return -EPERM;
68                         }
69                 }
70
71                 /*
72                  * The JOURNAL_DATA flag can only be changed by
73                  * the relevant capability.
74                  */
75                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
76                         if (!capable(CAP_SYS_RESOURCE)) {
77                                 mutex_unlock(&inode->i_mutex);
78                                 return -EPERM;
79                         }
80                 }
81
82
83                 handle = ext4_journal_start(inode, 1);
84                 if (IS_ERR(handle)) {
85                         mutex_unlock(&inode->i_mutex);
86                         return PTR_ERR(handle);
87                 }
88                 if (IS_SYNC(inode))
89                         handle->h_sync = 1;
90                 err = ext4_reserve_inode_write(handle, inode, &iloc);
91                 if (err)
92                         goto flags_err;
93
94                 flags = flags & EXT4_FL_USER_MODIFIABLE;
95                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
96                 ei->i_flags = flags;
97
98                 ext4_set_inode_flags(inode);
99                 inode->i_ctime = CURRENT_TIME_SEC;
100
101                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
102 flags_err:
103                 ext4_journal_stop(handle);
104                 if (err) {
105                         mutex_unlock(&inode->i_mutex);
106                         return err;
107                 }
108
109                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
110                         err = ext4_change_inode_journal_flag(inode, jflag);
111                 mutex_unlock(&inode->i_mutex);
112                 return err;
113         }
114         case EXT4_IOC_GETVERSION:
115         case EXT4_IOC_GETVERSION_OLD:
116                 return put_user(inode->i_generation, (int __user *) arg);
117         case EXT4_IOC_SETVERSION:
118         case EXT4_IOC_SETVERSION_OLD: {
119                 handle_t *handle;
120                 struct ext4_iloc iloc;
121                 __u32 generation;
122                 int err;
123
124                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
125                         return -EPERM;
126                 if (IS_RDONLY(inode))
127                         return -EROFS;
128                 if (get_user(generation, (int __user *) arg))
129                         return -EFAULT;
130
131                 handle = ext4_journal_start(inode, 1);
132                 if (IS_ERR(handle))
133                         return PTR_ERR(handle);
134                 err = ext4_reserve_inode_write(handle, inode, &iloc);
135                 if (err == 0) {
136                         inode->i_ctime = CURRENT_TIME_SEC;
137                         inode->i_generation = generation;
138                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
139                 }
140                 ext4_journal_stop(handle);
141                 return err;
142         }
143 #ifdef CONFIG_JBD_DEBUG
144         case EXT4_IOC_WAIT_FOR_READONLY:
145                 /*
146                  * This is racy - by the time we're woken up and running,
147                  * the superblock could be released.  And the module could
148                  * have been unloaded.  So sue me.
149                  *
150                  * Returns 1 if it slept, else zero.
151                  */
152                 {
153                         struct super_block *sb = inode->i_sb;
154                         DECLARE_WAITQUEUE(wait, current);
155                         int ret = 0;
156
157                         set_current_state(TASK_INTERRUPTIBLE);
158                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
159                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
160                                 schedule();
161                                 ret = 1;
162                         }
163                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
164                         return ret;
165                 }
166 #endif
167         case EXT4_IOC_GETRSVSZ:
168                 if (test_opt(inode->i_sb, RESERVATION)
169                         && S_ISREG(inode->i_mode)
170                         && ei->i_block_alloc_info) {
171                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
172                         return put_user(rsv_window_size, (int __user *)arg);
173                 }
174                 return -ENOTTY;
175         case EXT4_IOC_SETRSVSZ: {
176
177                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
178                         return -ENOTTY;
179
180                 if (IS_RDONLY(inode))
181                         return -EROFS;
182
183                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
184                         return -EACCES;
185
186                 if (get_user(rsv_window_size, (int __user *)arg))
187                         return -EFAULT;
188
189                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
190                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
191
192                 /*
193                  * need to allocate reservation structure for this inode
194                  * before set the window size
195                  */
196                 mutex_lock(&ei->truncate_mutex);
197                 if (!ei->i_block_alloc_info)
198                         ext4_init_block_alloc_info(inode);
199
200                 if (ei->i_block_alloc_info){
201                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
202                         rsv->rsv_goal_size = rsv_window_size;
203                 }
204                 mutex_unlock(&ei->truncate_mutex);
205                 return 0;
206         }
207         case EXT4_IOC_GROUP_EXTEND: {
208                 ext4_fsblk_t n_blocks_count;
209                 struct super_block *sb = inode->i_sb;
210                 int err;
211
212                 if (!capable(CAP_SYS_RESOURCE))
213                         return -EPERM;
214
215                 if (IS_RDONLY(inode))
216                         return -EROFS;
217
218                 if (get_user(n_blocks_count, (__u32 __user *)arg))
219                         return -EFAULT;
220
221                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
222                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
223                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
224                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
225
226                 return err;
227         }
228         case EXT4_IOC_GROUP_ADD: {
229                 struct ext4_new_group_data input;
230                 struct super_block *sb = inode->i_sb;
231                 int err;
232
233                 if (!capable(CAP_SYS_RESOURCE))
234                         return -EPERM;
235
236                 if (IS_RDONLY(inode))
237                         return -EROFS;
238
239                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
240                                 sizeof(input)))
241                         return -EFAULT;
242
243                 err = ext4_group_add(sb, &input);
244                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
245                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
246                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
247
248                 return err;
249         }
250
251         default:
252                 return -ENOTTY;
253         }
254 }
255
256 #ifdef CONFIG_COMPAT
257 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
258 {
259         struct inode *inode = file->f_path.dentry->d_inode;
260         int ret;
261
262         /* These are just misnamed, they actually get/put from/to user an int */
263         switch (cmd) {
264         case EXT4_IOC32_GETFLAGS:
265                 cmd = EXT4_IOC_GETFLAGS;
266                 break;
267         case EXT4_IOC32_SETFLAGS:
268                 cmd = EXT4_IOC_SETFLAGS;
269                 break;
270         case EXT4_IOC32_GETVERSION:
271                 cmd = EXT4_IOC_GETVERSION;
272                 break;
273         case EXT4_IOC32_SETVERSION:
274                 cmd = EXT4_IOC_SETVERSION;
275                 break;
276         case EXT4_IOC32_GROUP_EXTEND:
277                 cmd = EXT4_IOC_GROUP_EXTEND;
278                 break;
279         case EXT4_IOC32_GETVERSION_OLD:
280                 cmd = EXT4_IOC_GETVERSION_OLD;
281                 break;
282         case EXT4_IOC32_SETVERSION_OLD:
283                 cmd = EXT4_IOC_SETVERSION_OLD;
284                 break;
285 #ifdef CONFIG_JBD_DEBUG
286         case EXT4_IOC32_WAIT_FOR_READONLY:
287                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
288                 break;
289 #endif
290         case EXT4_IOC32_GETRSVSZ:
291                 cmd = EXT4_IOC_GETRSVSZ;
292                 break;
293         case EXT4_IOC32_SETRSVSZ:
294                 cmd = EXT4_IOC_SETRSVSZ;
295                 break;
296         case EXT4_IOC_GROUP_ADD:
297                 break;
298         default:
299                 return -ENOIOCTLCMD;
300         }
301         lock_kernel();
302         ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
303         unlock_kernel();
304         return ret;
305 }
306 #endif