aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ext4/ioctl.c
blob: a567af161b06af1d10c3840bf1da0e8989848ac4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
/*
 * linux/fs/ext4/ioctl.c
 *
 * Copyright (C) 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 */

#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/capability.h>
#include <linux/ext4_fs.h>
#include <linux/ext4_jbd.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>

int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
		unsigned long arg)
{
	struct ext4_inode_info *ei = EXT4_I(inode);
	unsigned int flags;
	unsigned short rsv_window_size;

	ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);

	switch (cmd) {
	case EXT4_IOC_GETFLAGS:
		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
		return put_user(flags, (int __user *) arg);
	case EXT4_IOC_SETFLAGS: {
		handle_t *handle = NULL;
		int err;
		struct ext4_iloc iloc;
		unsigned int oldflags;
		unsigned int jflag;

		if (IS_RDONLY(inode))
			return -EROFS;

		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
			return -EACCES;

		if (get_user(flags, (int __user *) arg))
			return -EFAULT;

		if (!S_ISDIR(inode->i_mode))
			flags &= ~EXT4_DIRSYNC_FL;

		mutex_lock(&inode->i_mutex);
		oldflags = ei->i_flags;

		/* The JOURNAL_DATA flag is modifiable only by root */
		jflag = flags & EXT4_JOURNAL_DATA_FL;

		/*
		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
		 * the relevant capability.
		 *
		 * This test looks nicer. Thanks to Pauline Middelink
		 */
		if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
			if (!capable(CAP_LINUX_IMMUTABLE)) {
				mutex_unlock(&inode->i_mutex);
				return -EPERM;
			}
		}

		/*
		 * The JOURNAL_DATA flag can only be changed by
		 * the relevant capability.
		 */
		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
			if (!capable(CAP_SYS_RESOURCE)) {
				mutex_unlock(&inode->i_mutex);
				return -EPERM;
			}
		}


		handle = ext4_journal_start(inode, 1);
		if (IS_ERR(handle)) {
			mutex_unlock(&inode->i_mutex);
			return PTR_ERR(handle);
		}
		if (IS_SYNC(inode))
			handle->h_sync = 1;
		err = ext4_reserve_inode_write(handle, inode, &iloc);
		if (err)
			goto flags_err;

		flags = flags & EXT4_FL_USER_MODIFIABLE;
		flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
		ei->i_flags = flags;

		ext4_set_inode_flags(inode);
		inode->i_ctime = CURRENT_TIME_SEC;

		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
		ext4_journal_stop(handle);
		if (err) {
			mutex_unlock(&inode->i_mutex);
			return err;
		}

		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
			err = ext4_change_inode_journal_flag(inode, jflag);
		mutex_unlock(&inode->i_mutex);
		return err;
	}
	case EXT4_IOC_GETVERSION:
	case EXT4_IOC_GETVERSION_OLD:
		return put_user(inode->i_generation, (int __user *) arg);
	case EXT4_IOC_SETVERSION:
	case EXT4_IOC_SETVERSION_OLD: {
		handle_t *handle;
		struct ext4_iloc iloc;
		__u32 generation;
		int err;

		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
			return -EPERM;
		if (IS_RDONLY(inode))
			return -EROFS;
		if (get_user(generation, (int __user *) arg))
			return -EFAULT;

		handle = ext4_journal_start(inode, 1);
		if (IS_ERR(handle))
			return PTR_ERR(handle);
		err = ext4_reserve_inode_write(handle, inode, &iloc);
		if (err == 0) {
			inode->i_ctime = CURRENT_TIME_SEC;
			inode->i_generation = generation;
			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
		}
		ext4_journal_stop(handle);
		return err;
	}
#ifdef CONFIG_JBD_DEBUG
	case EXT4_IOC_WAIT_FOR_READONLY:
		/*
		 * This is racy - by the time we're woken up and running,
		 * the superblock could be released.  And the module could
		 * have been unloaded.  So sue me.
		 *
		 * Returns 1 if it slept, else zero.
		 */
		{
			struct super_block *sb = inode->i_sb;
			DECLARE_WAITQUEUE(wait, current);
			int ret = 0;

			set_current_state(TASK_INTERRUPTIBLE);
			add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
			if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
				schedule();
				ret = 1;
			}
			remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
			return ret;
		}
#endif
	case EXT4_IOC_GETRSVSZ:
		if (test_opt(inode->i_sb, RESERVATION)
			&& S_ISREG(inode->i_mode)
			&& ei->i_block_alloc_info) {
			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
			return put_user(rsv_window_size, (int __user *)arg);
		}
		return -ENOTTY;
	case EXT4_IOC_SETRSVSZ: {

		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
			return -ENOTTY;

		if (IS_RDONLY(inode))
			return -EROFS;

		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
			return -EACCES;

		if (get_user(rsv_window_size, (int __user *)arg))
			return -EFAULT;

		if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
			rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;

		/*
		 * need to allocate reservation structure for this inode
		 * before set the window size
		 */
		mutex_lock(&ei->truncate_mutex);
		if (!ei->i_block_alloc_info)
			ext4_init_block_alloc_info(inode);

		if (ei->i_block_alloc_info){
			struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
			rsv->rsv_goal_size = rsv_window_size;
		}
		mutex_unlock(&ei->truncate_mutex);
		return 0;
	}
	case EXT4_IOC_GROUP_EXTEND: {
		ext4_fsblk_t n_blocks_count;
		struct super_block *sb = inode->i_sb;
		int err;

		if (!capable(CAP_SYS_RESOURCE))
			return -EPERM;

		if (IS_RDONLY(inode))
			return -EROFS;

		if (get_user(n_blocks_count, (__u32 __user *)arg))
			return -EFAULT;

		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
		journal_lock_updates(EXT4_SB(sb)->s_journal);
		journal_flush(EXT4_SB(sb)->s_journal);
		journal_unlock_updates(EXT4_SB(sb)->s_journal);

		return err;
	}
	case EXT4_IOC_GROUP_ADD: {
		struct ext4_new_group_data input;
		struct super_block *sb = inode->i_sb;
		int err;

		if (!capable(CAP_SYS_RESOURCE))
			return -EPERM;

		if (IS_RDONLY(inode))
			return -EROFS;

		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
				sizeof(input)))
			return -EFAULT;

		err = ext4_group_add(sb, &input);
		journal_lock_updates(EXT4_SB(sb)->s_journal);
		journal_flush(EXT4_SB(sb)->s_journal);
		journal_unlock_updates(EXT4_SB(sb)->s_journal);

		return err;
	}


	default:
		return -ENOTTY;
	}
}

#ifdef CONFIG_COMPAT
long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct inode *inode = file->f_dentry->d_inode;
	int ret;

	/* These are just misnamed, they actually get/put from/to user an int */
	switch (cmd) {
	case EXT4_IOC32_GETFLAGS:
		cmd = EXT4_IOC_GETFLAGS;
		break;
	case EXT4_IOC32_SETFLAGS:
		cmd = EXT4_IOC_SETFLAGS;
		break;
	case EXT4_IOC32_GETVERSION:
		cmd = EXT4_IOC_GETVERSION;
		break;
	case EXT4_IOC32_SETVERSION:
		cmd = EXT4_IOC_SETVERSION;
		break;
	case EXT4_IOC32_GROUP_EXTEND:
		cmd = EXT4_IOC_GROUP_EXTEND;
		break;
	case EXT4_IOC32_GETVERSION_OLD:
		cmd = EXT4_IOC_GETVERSION_OLD;
		break;
	case EXT4_IOC32_SETVERSION_OLD:
		cmd = EXT4_IOC_SETVERSION_OLD;
		break;
#ifdef CONFIG_JBD_DEBUG
	case EXT4_IOC32_WAIT_FOR_READONLY:
		cmd = EXT4_IOC_WAIT_FOR_READONLY;
		break;
#endif
	case EXT4_IOC32_GETRSVSZ:
		cmd = EXT4_IOC_GETRSVSZ;
		break;
	case EXT4_IOC32_SETRSVSZ:
		cmd = EXT4_IOC_SETRSVSZ;
		break;
	case EXT4_IOC_GROUP_ADD:
		break;
	default:
		return -ENOIOCTLCMD;
	}
	lock_kernel();
	ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
	unlock_kernel();
	return ret;
}
#endif