Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
[linux-2.6] / 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/time.h>
14 #include <linux/compat.h>
15 #include <linux/smp_lock.h>
16 #include <linux/mount.h>
17 #include <asm/uaccess.h>
18 #include "ext4_jbd2.h"
19 #include "ext4.h"
20
21 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
22 {
23         struct inode *inode = filp->f_dentry->d_inode;
24         struct ext4_inode_info *ei = EXT4_I(inode);
25         unsigned int flags;
26
27         ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
28
29         switch (cmd) {
30         case EXT4_IOC_GETFLAGS:
31                 ext4_get_inode_flags(ei);
32                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
33                 return put_user(flags, (int __user *) arg);
34         case EXT4_IOC_SETFLAGS: {
35                 handle_t *handle = NULL;
36                 int err, migrate = 0;
37                 struct ext4_iloc iloc;
38                 unsigned int oldflags;
39                 unsigned int jflag;
40
41                 if (!is_owner_or_cap(inode))
42                         return -EACCES;
43
44                 if (get_user(flags, (int __user *) arg))
45                         return -EFAULT;
46
47                 err = mnt_want_write(filp->f_path.mnt);
48                 if (err)
49                         return err;
50
51                 if (!S_ISDIR(inode->i_mode))
52                         flags &= ~EXT4_DIRSYNC_FL;
53
54                 err = -EPERM;
55                 mutex_lock(&inode->i_mutex);
56                 /* Is it quota file? Do not allow user to mess with it */
57                 if (IS_NOQUOTA(inode))
58                         goto flags_out;
59
60                 oldflags = ei->i_flags;
61
62                 /* The JOURNAL_DATA flag is modifiable only by root */
63                 jflag = flags & EXT4_JOURNAL_DATA_FL;
64
65                 /*
66                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
67                  * the relevant capability.
68                  *
69                  * This test looks nicer. Thanks to Pauline Middelink
70                  */
71                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
72                         if (!capable(CAP_LINUX_IMMUTABLE))
73                                 goto flags_out;
74                 }
75
76                 /*
77                  * The JOURNAL_DATA flag can only be changed by
78                  * the relevant capability.
79                  */
80                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
81                         if (!capable(CAP_SYS_RESOURCE))
82                                 goto flags_out;
83                 }
84                 if (oldflags & EXT4_EXTENTS_FL) {
85                         /* We don't support clearning extent flags */
86                         if (!(flags & EXT4_EXTENTS_FL)) {
87                                 err = -EOPNOTSUPP;
88                                 goto flags_out;
89                         }
90                 } else if (flags & EXT4_EXTENTS_FL) {
91                         /* migrate the file */
92                         migrate = 1;
93                         flags &= ~EXT4_EXTENTS_FL;
94                 }
95
96                 handle = ext4_journal_start(inode, 1);
97                 if (IS_ERR(handle)) {
98                         err = PTR_ERR(handle);
99                         goto flags_out;
100                 }
101                 if (IS_SYNC(inode))
102                         ext4_handle_sync(handle);
103                 err = ext4_reserve_inode_write(handle, inode, &iloc);
104                 if (err)
105                         goto flags_err;
106
107                 flags = flags & EXT4_FL_USER_MODIFIABLE;
108                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
109                 ei->i_flags = flags;
110
111                 ext4_set_inode_flags(inode);
112                 inode->i_ctime = ext4_current_time(inode);
113
114                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
115 flags_err:
116                 ext4_journal_stop(handle);
117                 if (err)
118                         goto flags_out;
119
120                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
121                         err = ext4_change_inode_journal_flag(inode, jflag);
122                 if (err)
123                         goto flags_out;
124                 if (migrate)
125                         err = ext4_ext_migrate(inode);
126 flags_out:
127                 mutex_unlock(&inode->i_mutex);
128                 mnt_drop_write(filp->f_path.mnt);
129                 return err;
130         }
131         case EXT4_IOC_GETVERSION:
132         case EXT4_IOC_GETVERSION_OLD:
133                 return put_user(inode->i_generation, (int __user *) arg);
134         case EXT4_IOC_SETVERSION:
135         case EXT4_IOC_SETVERSION_OLD: {
136                 handle_t *handle;
137                 struct ext4_iloc iloc;
138                 __u32 generation;
139                 int err;
140
141                 if (!is_owner_or_cap(inode))
142                         return -EPERM;
143
144                 err = mnt_want_write(filp->f_path.mnt);
145                 if (err)
146                         return err;
147                 if (get_user(generation, (int __user *) arg)) {
148                         err = -EFAULT;
149                         goto setversion_out;
150                 }
151
152                 handle = ext4_journal_start(inode, 1);
153                 if (IS_ERR(handle)) {
154                         err = PTR_ERR(handle);
155                         goto setversion_out;
156                 }
157                 err = ext4_reserve_inode_write(handle, inode, &iloc);
158                 if (err == 0) {
159                         inode->i_ctime = ext4_current_time(inode);
160                         inode->i_generation = generation;
161                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
162                 }
163                 ext4_journal_stop(handle);
164 setversion_out:
165                 mnt_drop_write(filp->f_path.mnt);
166                 return err;
167         }
168 #ifdef CONFIG_JBD2_DEBUG
169         case EXT4_IOC_WAIT_FOR_READONLY:
170                 /*
171                  * This is racy - by the time we're woken up and running,
172                  * the superblock could be released.  And the module could
173                  * have been unloaded.  So sue me.
174                  *
175                  * Returns 1 if it slept, else zero.
176                  */
177                 {
178                         struct super_block *sb = inode->i_sb;
179                         DECLARE_WAITQUEUE(wait, current);
180                         int ret = 0;
181
182                         set_current_state(TASK_INTERRUPTIBLE);
183                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
184                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
185                                 schedule();
186                                 ret = 1;
187                         }
188                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
189                         return ret;
190                 }
191 #endif
192         case EXT4_IOC_GROUP_EXTEND: {
193                 ext4_fsblk_t n_blocks_count;
194                 struct super_block *sb = inode->i_sb;
195                 int err, err2;
196
197                 if (!capable(CAP_SYS_RESOURCE))
198                         return -EPERM;
199
200                 if (get_user(n_blocks_count, (__u32 __user *)arg))
201                         return -EFAULT;
202
203                 err = mnt_want_write(filp->f_path.mnt);
204                 if (err)
205                         return err;
206
207                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
208                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
209                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
210                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
211                 if (err == 0)
212                         err = err2;
213                 mnt_drop_write(filp->f_path.mnt);
214
215                 return err;
216         }
217         case EXT4_IOC_GROUP_ADD: {
218                 struct ext4_new_group_data input;
219                 struct super_block *sb = inode->i_sb;
220                 int err, err2;
221
222                 if (!capable(CAP_SYS_RESOURCE))
223                         return -EPERM;
224
225                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
226                                 sizeof(input)))
227                         return -EFAULT;
228
229                 err = mnt_want_write(filp->f_path.mnt);
230                 if (err)
231                         return err;
232
233                 err = ext4_group_add(sb, &input);
234                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
235                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
236                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
237                 if (err == 0)
238                         err = err2;
239                 mnt_drop_write(filp->f_path.mnt);
240
241                 return err;
242         }
243
244         case EXT4_IOC_MIGRATE:
245         {
246                 int err;
247                 if (!is_owner_or_cap(inode))
248                         return -EACCES;
249
250                 err = mnt_want_write(filp->f_path.mnt);
251                 if (err)
252                         return err;
253                 /*
254                  * inode_mutex prevent write and truncate on the file.
255                  * Read still goes through. We take i_data_sem in
256                  * ext4_ext_swap_inode_data before we switch the
257                  * inode format to prevent read.
258                  */
259                 mutex_lock(&(inode->i_mutex));
260                 err = ext4_ext_migrate(inode);
261                 mutex_unlock(&(inode->i_mutex));
262                 mnt_drop_write(filp->f_path.mnt);
263                 return err;
264         }
265
266         default:
267                 return -ENOTTY;
268         }
269 }
270
271 #ifdef CONFIG_COMPAT
272 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
273 {
274         /* These are just misnamed, they actually get/put from/to user an int */
275         switch (cmd) {
276         case EXT4_IOC32_GETFLAGS:
277                 cmd = EXT4_IOC_GETFLAGS;
278                 break;
279         case EXT4_IOC32_SETFLAGS:
280                 cmd = EXT4_IOC_SETFLAGS;
281                 break;
282         case EXT4_IOC32_GETVERSION:
283                 cmd = EXT4_IOC_GETVERSION;
284                 break;
285         case EXT4_IOC32_SETVERSION:
286                 cmd = EXT4_IOC_SETVERSION;
287                 break;
288         case EXT4_IOC32_GROUP_EXTEND:
289                 cmd = EXT4_IOC_GROUP_EXTEND;
290                 break;
291         case EXT4_IOC32_GETVERSION_OLD:
292                 cmd = EXT4_IOC_GETVERSION_OLD;
293                 break;
294         case EXT4_IOC32_SETVERSION_OLD:
295                 cmd = EXT4_IOC_SETVERSION_OLD;
296                 break;
297 #ifdef CONFIG_JBD2_DEBUG
298         case EXT4_IOC32_WAIT_FOR_READONLY:
299                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
300                 break;
301 #endif
302         case EXT4_IOC32_GETRSVSZ:
303                 cmd = EXT4_IOC_GETRSVSZ;
304                 break;
305         case EXT4_IOC32_SETRSVSZ:
306                 cmd = EXT4_IOC_SETRSVSZ;
307                 break;
308         case EXT4_IOC_GROUP_ADD:
309                 break;
310         default:
311                 return -ENOIOCTLCMD;
312         }
313         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
314 }
315 #endif