xref: /openbmc/linux/fs/ext4/ioctl.c (revision 545e4006)
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 	unsigned short rsv_window_size;
27 
28 	ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);
29 
30 	switch (cmd) {
31 	case EXT4_IOC_GETFLAGS:
32 		ext4_get_inode_flags(ei);
33 		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
34 		return put_user(flags, (int __user *) arg);
35 	case EXT4_IOC_SETFLAGS: {
36 		handle_t *handle = NULL;
37 		int err;
38 		struct ext4_iloc iloc;
39 		unsigned int oldflags;
40 		unsigned int jflag;
41 
42 		if (!is_owner_or_cap(inode))
43 			return -EACCES;
44 
45 		if (get_user(flags, (int __user *) arg))
46 			return -EFAULT;
47 
48 		err = mnt_want_write(filp->f_path.mnt);
49 		if (err)
50 			return err;
51 
52 		if (!S_ISDIR(inode->i_mode))
53 			flags &= ~EXT4_DIRSYNC_FL;
54 
55 		err = -EPERM;
56 		mutex_lock(&inode->i_mutex);
57 		/* Is it quota file? Do not allow user to mess with it */
58 		if (IS_NOQUOTA(inode))
59 			goto flags_out;
60 
61 		oldflags = ei->i_flags;
62 
63 		/* The JOURNAL_DATA flag is modifiable only by root */
64 		jflag = flags & EXT4_JOURNAL_DATA_FL;
65 
66 		/*
67 		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
68 		 * the relevant capability.
69 		 *
70 		 * This test looks nicer. Thanks to Pauline Middelink
71 		 */
72 		if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
73 			if (!capable(CAP_LINUX_IMMUTABLE))
74 				goto flags_out;
75 		}
76 
77 		/*
78 		 * The JOURNAL_DATA flag can only be changed by
79 		 * the relevant capability.
80 		 */
81 		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
82 			if (!capable(CAP_SYS_RESOURCE))
83 				goto flags_out;
84 		}
85 
86 		handle = ext4_journal_start(inode, 1);
87 		if (IS_ERR(handle)) {
88 			err = PTR_ERR(handle);
89 			goto flags_out;
90 		}
91 		if (IS_SYNC(inode))
92 			handle->h_sync = 1;
93 		err = ext4_reserve_inode_write(handle, inode, &iloc);
94 		if (err)
95 			goto flags_err;
96 
97 		flags = flags & EXT4_FL_USER_MODIFIABLE;
98 		flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
99 		ei->i_flags = flags;
100 
101 		ext4_set_inode_flags(inode);
102 		inode->i_ctime = ext4_current_time(inode);
103 
104 		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
105 flags_err:
106 		ext4_journal_stop(handle);
107 		if (err)
108 			goto flags_out;
109 
110 		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
111 			err = ext4_change_inode_journal_flag(inode, jflag);
112 flags_out:
113 		mutex_unlock(&inode->i_mutex);
114 		mnt_drop_write(filp->f_path.mnt);
115 		return err;
116 	}
117 	case EXT4_IOC_GETVERSION:
118 	case EXT4_IOC_GETVERSION_OLD:
119 		return put_user(inode->i_generation, (int __user *) arg);
120 	case EXT4_IOC_SETVERSION:
121 	case EXT4_IOC_SETVERSION_OLD: {
122 		handle_t *handle;
123 		struct ext4_iloc iloc;
124 		__u32 generation;
125 		int err;
126 
127 		if (!is_owner_or_cap(inode))
128 			return -EPERM;
129 
130 		err = mnt_want_write(filp->f_path.mnt);
131 		if (err)
132 			return err;
133 		if (get_user(generation, (int __user *) arg)) {
134 			err = -EFAULT;
135 			goto setversion_out;
136 		}
137 
138 		handle = ext4_journal_start(inode, 1);
139 		if (IS_ERR(handle)) {
140 			err = PTR_ERR(handle);
141 			goto setversion_out;
142 		}
143 		err = ext4_reserve_inode_write(handle, inode, &iloc);
144 		if (err == 0) {
145 			inode->i_ctime = ext4_current_time(inode);
146 			inode->i_generation = generation;
147 			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
148 		}
149 		ext4_journal_stop(handle);
150 setversion_out:
151 		mnt_drop_write(filp->f_path.mnt);
152 		return err;
153 	}
154 #ifdef CONFIG_JBD2_DEBUG
155 	case EXT4_IOC_WAIT_FOR_READONLY:
156 		/*
157 		 * This is racy - by the time we're woken up and running,
158 		 * the superblock could be released.  And the module could
159 		 * have been unloaded.  So sue me.
160 		 *
161 		 * Returns 1 if it slept, else zero.
162 		 */
163 		{
164 			struct super_block *sb = inode->i_sb;
165 			DECLARE_WAITQUEUE(wait, current);
166 			int ret = 0;
167 
168 			set_current_state(TASK_INTERRUPTIBLE);
169 			add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
170 			if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
171 				schedule();
172 				ret = 1;
173 			}
174 			remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
175 			return ret;
176 		}
177 #endif
178 	case EXT4_IOC_GETRSVSZ:
179 		if (test_opt(inode->i_sb, RESERVATION)
180 			&& S_ISREG(inode->i_mode)
181 			&& ei->i_block_alloc_info) {
182 			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
183 			return put_user(rsv_window_size, (int __user *)arg);
184 		}
185 		return -ENOTTY;
186 	case EXT4_IOC_SETRSVSZ: {
187 		int err;
188 
189 		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
190 			return -ENOTTY;
191 
192 		if (!is_owner_or_cap(inode))
193 			return -EACCES;
194 
195 		if (get_user(rsv_window_size, (int __user *)arg))
196 			return -EFAULT;
197 
198 		err = mnt_want_write(filp->f_path.mnt);
199 		if (err)
200 			return err;
201 
202 		if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
203 			rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
204 
205 		/*
206 		 * need to allocate reservation structure for this inode
207 		 * before set the window size
208 		 */
209 		down_write(&ei->i_data_sem);
210 		if (!ei->i_block_alloc_info)
211 			ext4_init_block_alloc_info(inode);
212 
213 		if (ei->i_block_alloc_info){
214 			struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
215 			rsv->rsv_goal_size = rsv_window_size;
216 		}
217 		up_write(&ei->i_data_sem);
218 		mnt_drop_write(filp->f_path.mnt);
219 		return 0;
220 	}
221 	case EXT4_IOC_GROUP_EXTEND: {
222 		ext4_fsblk_t n_blocks_count;
223 		struct super_block *sb = inode->i_sb;
224 		int err;
225 
226 		if (!capable(CAP_SYS_RESOURCE))
227 			return -EPERM;
228 
229 		if (get_user(n_blocks_count, (__u32 __user *)arg))
230 			return -EFAULT;
231 
232 		err = mnt_want_write(filp->f_path.mnt);
233 		if (err)
234 			return err;
235 
236 		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
237 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
238 		jbd2_journal_flush(EXT4_SB(sb)->s_journal);
239 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
240 		mnt_drop_write(filp->f_path.mnt);
241 
242 		return err;
243 	}
244 	case EXT4_IOC_GROUP_ADD: {
245 		struct ext4_new_group_data input;
246 		struct super_block *sb = inode->i_sb;
247 		int err;
248 
249 		if (!capable(CAP_SYS_RESOURCE))
250 			return -EPERM;
251 
252 		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
253 				sizeof(input)))
254 			return -EFAULT;
255 
256 		err = mnt_want_write(filp->f_path.mnt);
257 		if (err)
258 			return err;
259 
260 		err = ext4_group_add(sb, &input);
261 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
262 		jbd2_journal_flush(EXT4_SB(sb)->s_journal);
263 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
264 		mnt_drop_write(filp->f_path.mnt);
265 
266 		return err;
267 	}
268 
269 	case EXT4_IOC_MIGRATE:
270 		return ext4_ext_migrate(inode, filp, cmd, arg);
271 
272 	default:
273 		return -ENOTTY;
274 	}
275 }
276 
277 #ifdef CONFIG_COMPAT
278 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
279 {
280 	/* These are just misnamed, they actually get/put from/to user an int */
281 	switch (cmd) {
282 	case EXT4_IOC32_GETFLAGS:
283 		cmd = EXT4_IOC_GETFLAGS;
284 		break;
285 	case EXT4_IOC32_SETFLAGS:
286 		cmd = EXT4_IOC_SETFLAGS;
287 		break;
288 	case EXT4_IOC32_GETVERSION:
289 		cmd = EXT4_IOC_GETVERSION;
290 		break;
291 	case EXT4_IOC32_SETVERSION:
292 		cmd = EXT4_IOC_SETVERSION;
293 		break;
294 	case EXT4_IOC32_GROUP_EXTEND:
295 		cmd = EXT4_IOC_GROUP_EXTEND;
296 		break;
297 	case EXT4_IOC32_GETVERSION_OLD:
298 		cmd = EXT4_IOC_GETVERSION_OLD;
299 		break;
300 	case EXT4_IOC32_SETVERSION_OLD:
301 		cmd = EXT4_IOC_SETVERSION_OLD;
302 		break;
303 #ifdef CONFIG_JBD2_DEBUG
304 	case EXT4_IOC32_WAIT_FOR_READONLY:
305 		cmd = EXT4_IOC_WAIT_FOR_READONLY;
306 		break;
307 #endif
308 	case EXT4_IOC32_GETRSVSZ:
309 		cmd = EXT4_IOC_GETRSVSZ;
310 		break;
311 	case EXT4_IOC32_SETRSVSZ:
312 		cmd = EXT4_IOC_SETRSVSZ;
313 		break;
314 	case EXT4_IOC_GROUP_ADD:
315 		break;
316 	default:
317 		return -ENOIOCTLCMD;
318 	}
319 	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
320 }
321 #endif
322