xref: /openbmc/linux/fs/ext4/ioctl.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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
307