xref: /openbmc/linux/fs/ext4/ioctl.c (revision 171f1bc7)
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/mount.h>
16 #include <linux/file.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 super_block *sb = inode->i_sb;
25 	struct ext4_inode_info *ei = EXT4_I(inode);
26 	unsigned int flags;
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, migrate = 0;
38 		struct ext4_iloc iloc;
39 		unsigned int oldflags;
40 		unsigned int jflag;
41 
42 		if (!inode_owner_or_capable(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 		flags = ext4_mask_flags(inode->i_mode, flags);
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 		if (flags & EXT4_EOFBLOCKS_FL) {
97 			/* we don't support adding EOFBLOCKS flag */
98 			if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
99 				err = -EOPNOTSUPP;
100 				goto flags_out;
101 			}
102 		} else if (oldflags & EXT4_EOFBLOCKS_FL)
103 			ext4_truncate(inode);
104 
105 		handle = ext4_journal_start(inode, 1);
106 		if (IS_ERR(handle)) {
107 			err = PTR_ERR(handle);
108 			goto flags_out;
109 		}
110 		if (IS_SYNC(inode))
111 			ext4_handle_sync(handle);
112 		err = ext4_reserve_inode_write(handle, inode, &iloc);
113 		if (err)
114 			goto flags_err;
115 
116 		flags = flags & EXT4_FL_USER_MODIFIABLE;
117 		flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
118 		ei->i_flags = flags;
119 
120 		ext4_set_inode_flags(inode);
121 		inode->i_ctime = ext4_current_time(inode);
122 
123 		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
124 flags_err:
125 		ext4_journal_stop(handle);
126 		if (err)
127 			goto flags_out;
128 
129 		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
130 			err = ext4_change_inode_journal_flag(inode, jflag);
131 		if (err)
132 			goto flags_out;
133 		if (migrate)
134 			err = ext4_ext_migrate(inode);
135 flags_out:
136 		mutex_unlock(&inode->i_mutex);
137 		mnt_drop_write(filp->f_path.mnt);
138 		return err;
139 	}
140 	case EXT4_IOC_GETVERSION:
141 	case EXT4_IOC_GETVERSION_OLD:
142 		return put_user(inode->i_generation, (int __user *) arg);
143 	case EXT4_IOC_SETVERSION:
144 	case EXT4_IOC_SETVERSION_OLD: {
145 		handle_t *handle;
146 		struct ext4_iloc iloc;
147 		__u32 generation;
148 		int err;
149 
150 		if (!inode_owner_or_capable(inode))
151 			return -EPERM;
152 
153 		err = mnt_want_write(filp->f_path.mnt);
154 		if (err)
155 			return err;
156 		if (get_user(generation, (int __user *) arg)) {
157 			err = -EFAULT;
158 			goto setversion_out;
159 		}
160 
161 		handle = ext4_journal_start(inode, 1);
162 		if (IS_ERR(handle)) {
163 			err = PTR_ERR(handle);
164 			goto setversion_out;
165 		}
166 		err = ext4_reserve_inode_write(handle, inode, &iloc);
167 		if (err == 0) {
168 			inode->i_ctime = ext4_current_time(inode);
169 			inode->i_generation = generation;
170 			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
171 		}
172 		ext4_journal_stop(handle);
173 setversion_out:
174 		mnt_drop_write(filp->f_path.mnt);
175 		return err;
176 	}
177 	case EXT4_IOC_GROUP_EXTEND: {
178 		ext4_fsblk_t n_blocks_count;
179 		int err, err2=0;
180 
181 		err = ext4_resize_begin(sb);
182 		if (err)
183 			return err;
184 
185 		if (get_user(n_blocks_count, (__u32 __user *)arg))
186 			return -EFAULT;
187 
188 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
189 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
190 			ext4_msg(sb, KERN_ERR,
191 				 "Online resizing not supported with bigalloc");
192 			return -EOPNOTSUPP;
193 		}
194 
195 		err = mnt_want_write(filp->f_path.mnt);
196 		if (err)
197 			return err;
198 
199 		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
200 		if (EXT4_SB(sb)->s_journal) {
201 			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
202 			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
203 			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
204 		}
205 		if (err == 0)
206 			err = err2;
207 		mnt_drop_write(filp->f_path.mnt);
208 		ext4_resize_end(sb);
209 
210 		return err;
211 	}
212 
213 	case EXT4_IOC_MOVE_EXT: {
214 		struct move_extent me;
215 		struct file *donor_filp;
216 		int err;
217 
218 		if (!(filp->f_mode & FMODE_READ) ||
219 		    !(filp->f_mode & FMODE_WRITE))
220 			return -EBADF;
221 
222 		if (copy_from_user(&me,
223 			(struct move_extent __user *)arg, sizeof(me)))
224 			return -EFAULT;
225 		me.moved_len = 0;
226 
227 		donor_filp = fget(me.donor_fd);
228 		if (!donor_filp)
229 			return -EBADF;
230 
231 		if (!(donor_filp->f_mode & FMODE_WRITE)) {
232 			err = -EBADF;
233 			goto mext_out;
234 		}
235 
236 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
237 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
238 			ext4_msg(sb, KERN_ERR,
239 				 "Online defrag not supported with bigalloc");
240 			return -EOPNOTSUPP;
241 		}
242 
243 		err = mnt_want_write(filp->f_path.mnt);
244 		if (err)
245 			goto mext_out;
246 
247 		err = ext4_move_extents(filp, donor_filp, me.orig_start,
248 					me.donor_start, me.len, &me.moved_len);
249 		mnt_drop_write(filp->f_path.mnt);
250 		if (me.moved_len > 0)
251 			file_remove_suid(donor_filp);
252 
253 		if (copy_to_user((struct move_extent __user *)arg,
254 				 &me, sizeof(me)))
255 			err = -EFAULT;
256 mext_out:
257 		fput(donor_filp);
258 		return err;
259 	}
260 
261 	case EXT4_IOC_GROUP_ADD: {
262 		struct ext4_new_group_data input;
263 		int err, err2=0;
264 
265 		err = ext4_resize_begin(sb);
266 		if (err)
267 			return err;
268 
269 		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
270 				sizeof(input)))
271 			return -EFAULT;
272 
273 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
274 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
275 			ext4_msg(sb, KERN_ERR,
276 				 "Online resizing not supported with bigalloc");
277 			return -EOPNOTSUPP;
278 		}
279 
280 		err = mnt_want_write(filp->f_path.mnt);
281 		if (err)
282 			return err;
283 
284 		err = ext4_group_add(sb, &input);
285 		if (EXT4_SB(sb)->s_journal) {
286 			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
287 			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
288 			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
289 		}
290 		if (err == 0)
291 			err = err2;
292 		mnt_drop_write(filp->f_path.mnt);
293 		ext4_resize_end(sb);
294 
295 		return err;
296 	}
297 
298 	case EXT4_IOC_MIGRATE:
299 	{
300 		int err;
301 		if (!inode_owner_or_capable(inode))
302 			return -EACCES;
303 
304 		err = mnt_want_write(filp->f_path.mnt);
305 		if (err)
306 			return err;
307 		/*
308 		 * inode_mutex prevent write and truncate on the file.
309 		 * Read still goes through. We take i_data_sem in
310 		 * ext4_ext_swap_inode_data before we switch the
311 		 * inode format to prevent read.
312 		 */
313 		mutex_lock(&(inode->i_mutex));
314 		err = ext4_ext_migrate(inode);
315 		mutex_unlock(&(inode->i_mutex));
316 		mnt_drop_write(filp->f_path.mnt);
317 		return err;
318 	}
319 
320 	case EXT4_IOC_ALLOC_DA_BLKS:
321 	{
322 		int err;
323 		if (!inode_owner_or_capable(inode))
324 			return -EACCES;
325 
326 		err = mnt_want_write(filp->f_path.mnt);
327 		if (err)
328 			return err;
329 		err = ext4_alloc_da_blocks(inode);
330 		mnt_drop_write(filp->f_path.mnt);
331 		return err;
332 	}
333 
334 	case FITRIM:
335 	{
336 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
337 		struct fstrim_range range;
338 		int ret = 0;
339 
340 		if (!capable(CAP_SYS_ADMIN))
341 			return -EPERM;
342 
343 		if (!blk_queue_discard(q))
344 			return -EOPNOTSUPP;
345 
346 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
347 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
348 			ext4_msg(sb, KERN_ERR,
349 				 "FITRIM not supported with bigalloc");
350 			return -EOPNOTSUPP;
351 		}
352 
353 		if (copy_from_user(&range, (struct fstrim_range __user *)arg,
354 		    sizeof(range)))
355 			return -EFAULT;
356 
357 		range.minlen = max((unsigned int)range.minlen,
358 				   q->limits.discard_granularity);
359 		ret = ext4_trim_fs(sb, &range);
360 		if (ret < 0)
361 			return ret;
362 
363 		if (copy_to_user((struct fstrim_range __user *)arg, &range,
364 		    sizeof(range)))
365 			return -EFAULT;
366 
367 		return 0;
368 	}
369 
370 	default:
371 		return -ENOTTY;
372 	}
373 }
374 
375 #ifdef CONFIG_COMPAT
376 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
377 {
378 	/* These are just misnamed, they actually get/put from/to user an int */
379 	switch (cmd) {
380 	case EXT4_IOC32_GETFLAGS:
381 		cmd = EXT4_IOC_GETFLAGS;
382 		break;
383 	case EXT4_IOC32_SETFLAGS:
384 		cmd = EXT4_IOC_SETFLAGS;
385 		break;
386 	case EXT4_IOC32_GETVERSION:
387 		cmd = EXT4_IOC_GETVERSION;
388 		break;
389 	case EXT4_IOC32_SETVERSION:
390 		cmd = EXT4_IOC_SETVERSION;
391 		break;
392 	case EXT4_IOC32_GROUP_EXTEND:
393 		cmd = EXT4_IOC_GROUP_EXTEND;
394 		break;
395 	case EXT4_IOC32_GETVERSION_OLD:
396 		cmd = EXT4_IOC_GETVERSION_OLD;
397 		break;
398 	case EXT4_IOC32_SETVERSION_OLD:
399 		cmd = EXT4_IOC_SETVERSION_OLD;
400 		break;
401 	case EXT4_IOC32_GETRSVSZ:
402 		cmd = EXT4_IOC_GETRSVSZ;
403 		break;
404 	case EXT4_IOC32_SETRSVSZ:
405 		cmd = EXT4_IOC_SETRSVSZ;
406 		break;
407 	case EXT4_IOC32_GROUP_ADD: {
408 		struct compat_ext4_new_group_input __user *uinput;
409 		struct ext4_new_group_input input;
410 		mm_segment_t old_fs;
411 		int err;
412 
413 		uinput = compat_ptr(arg);
414 		err = get_user(input.group, &uinput->group);
415 		err |= get_user(input.block_bitmap, &uinput->block_bitmap);
416 		err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
417 		err |= get_user(input.inode_table, &uinput->inode_table);
418 		err |= get_user(input.blocks_count, &uinput->blocks_count);
419 		err |= get_user(input.reserved_blocks,
420 				&uinput->reserved_blocks);
421 		if (err)
422 			return -EFAULT;
423 		old_fs = get_fs();
424 		set_fs(KERNEL_DS);
425 		err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
426 				 (unsigned long) &input);
427 		set_fs(old_fs);
428 		return err;
429 	}
430 	case EXT4_IOC_MOVE_EXT:
431 	case FITRIM:
432 		break;
433 	default:
434 		return -ENOIOCTLCMD;
435 	}
436 	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
437 }
438 #endif
439