Root/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/mount.h>
16#include <linux/file.h>
17#include <asm/uaccess.h>
18#include "ext4_jbd2.h"
19#include "ext4.h"
20
21long 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        flags = ext4_mask_flags(inode->i_mode, flags);
52
53        err = -EPERM;
54        mutex_lock(&inode->i_mutex);
55        /* Is it quota file? Do not allow user to mess with it */
56        if (IS_NOQUOTA(inode))
57            goto flags_out;
58
59        oldflags = ei->i_flags;
60
61        /* The JOURNAL_DATA flag is modifiable only by root */
62        jflag = flags & EXT4_JOURNAL_DATA_FL;
63
64        /*
65         * The IMMUTABLE and APPEND_ONLY flags can only be changed by
66         * the relevant capability.
67         *
68         * This test looks nicer. Thanks to Pauline Middelink
69         */
70        if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
71            if (!capable(CAP_LINUX_IMMUTABLE))
72                goto flags_out;
73        }
74
75        /*
76         * The JOURNAL_DATA flag can only be changed by
77         * the relevant capability.
78         */
79        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
80            if (!capable(CAP_SYS_RESOURCE))
81                goto flags_out;
82        }
83        if (oldflags & EXT4_EXTENTS_FL) {
84            /* We don't support clearning extent flags */
85            if (!(flags & EXT4_EXTENTS_FL)) {
86                err = -EOPNOTSUPP;
87                goto flags_out;
88            }
89        } else if (flags & EXT4_EXTENTS_FL) {
90            /* migrate the file */
91            migrate = 1;
92            flags &= ~EXT4_EXTENTS_FL;
93        }
94
95        handle = ext4_journal_start(inode, 1);
96        if (IS_ERR(handle)) {
97            err = PTR_ERR(handle);
98            goto flags_out;
99        }
100        if (IS_SYNC(inode))
101            ext4_handle_sync(handle);
102        err = ext4_reserve_inode_write(handle, inode, &iloc);
103        if (err)
104            goto flags_err;
105
106        flags = flags & EXT4_FL_USER_MODIFIABLE;
107        flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
108        ei->i_flags = flags;
109
110        ext4_set_inode_flags(inode);
111        inode->i_ctime = ext4_current_time(inode);
112
113        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
114flags_err:
115        ext4_journal_stop(handle);
116        if (err)
117            goto flags_out;
118
119        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
120            err = ext4_change_inode_journal_flag(inode, jflag);
121        if (err)
122            goto flags_out;
123        if (migrate)
124            err = ext4_ext_migrate(inode);
125flags_out:
126        mutex_unlock(&inode->i_mutex);
127        mnt_drop_write(filp->f_path.mnt);
128        return err;
129    }
130    case EXT4_IOC_GETVERSION:
131    case EXT4_IOC_GETVERSION_OLD:
132        return put_user(inode->i_generation, (int __user *) arg);
133    case EXT4_IOC_SETVERSION:
134    case EXT4_IOC_SETVERSION_OLD: {
135        handle_t *handle;
136        struct ext4_iloc iloc;
137        __u32 generation;
138        int err;
139
140        if (!is_owner_or_cap(inode))
141            return -EPERM;
142
143        err = mnt_want_write(filp->f_path.mnt);
144        if (err)
145            return err;
146        if (get_user(generation, (int __user *) arg)) {
147            err = -EFAULT;
148            goto setversion_out;
149        }
150
151        handle = ext4_journal_start(inode, 1);
152        if (IS_ERR(handle)) {
153            err = PTR_ERR(handle);
154            goto setversion_out;
155        }
156        err = ext4_reserve_inode_write(handle, inode, &iloc);
157        if (err == 0) {
158            inode->i_ctime = ext4_current_time(inode);
159            inode->i_generation = generation;
160            err = ext4_mark_iloc_dirty(handle, inode, &iloc);
161        }
162        ext4_journal_stop(handle);
163setversion_out:
164        mnt_drop_write(filp->f_path.mnt);
165        return err;
166    }
167#ifdef CONFIG_JBD2_DEBUG
168    case EXT4_IOC_WAIT_FOR_READONLY:
169        /*
170         * This is racy - by the time we're woken up and running,
171         * the superblock could be released. And the module could
172         * have been unloaded. So sue me.
173         *
174         * Returns 1 if it slept, else zero.
175         */
176        {
177            struct super_block *sb = inode->i_sb;
178            DECLARE_WAITQUEUE(wait, current);
179            int ret = 0;
180
181            set_current_state(TASK_INTERRUPTIBLE);
182            add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
183            if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
184                schedule();
185                ret = 1;
186            }
187            remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
188            return ret;
189        }
190#endif
191    case EXT4_IOC_GROUP_EXTEND: {
192        ext4_fsblk_t n_blocks_count;
193        struct super_block *sb = inode->i_sb;
194        int err, err2=0;
195
196        if (!capable(CAP_SYS_RESOURCE))
197            return -EPERM;
198
199        if (get_user(n_blocks_count, (__u32 __user *)arg))
200            return -EFAULT;
201
202        err = mnt_want_write(filp->f_path.mnt);
203        if (err)
204            return err;
205
206        err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
207        if (EXT4_SB(sb)->s_journal) {
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        }
212        if (err == 0)
213            err = err2;
214        mnt_drop_write(filp->f_path.mnt);
215
216        return err;
217    }
218
219    case EXT4_IOC_MOVE_EXT: {
220        struct move_extent me;
221        struct file *donor_filp;
222        int err;
223
224        if (copy_from_user(&me,
225            (struct move_extent __user *)arg, sizeof(me)))
226            return -EFAULT;
227
228        donor_filp = fget(me.donor_fd);
229        if (!donor_filp)
230            return -EBADF;
231
232        if (!capable(CAP_DAC_OVERRIDE)) {
233            if ((current->real_cred->fsuid != inode->i_uid) ||
234                !(inode->i_mode & S_IRUSR) ||
235                !(donor_filp->f_dentry->d_inode->i_mode &
236                S_IRUSR)) {
237                fput(donor_filp);
238                return -EACCES;
239            }
240        }
241
242        err = ext4_move_extents(filp, donor_filp, me.orig_start,
243                    me.donor_start, me.len, &me.moved_len);
244        fput(donor_filp);
245
246        if (!err)
247            if (copy_to_user((struct move_extent *)arg,
248                &me, sizeof(me)))
249                return -EFAULT;
250        return err;
251    }
252
253    case EXT4_IOC_GROUP_ADD: {
254        struct ext4_new_group_data input;
255        struct super_block *sb = inode->i_sb;
256        int err, err2=0;
257
258        if (!capable(CAP_SYS_RESOURCE))
259            return -EPERM;
260
261        if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
262                sizeof(input)))
263            return -EFAULT;
264
265        err = mnt_want_write(filp->f_path.mnt);
266        if (err)
267            return err;
268
269        err = ext4_group_add(sb, &input);
270        if (EXT4_SB(sb)->s_journal) {
271            jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
272            err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
273            jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
274        }
275        if (err == 0)
276            err = err2;
277        mnt_drop_write(filp->f_path.mnt);
278
279        return err;
280    }
281
282    case EXT4_IOC_MIGRATE:
283    {
284        int err;
285        if (!is_owner_or_cap(inode))
286            return -EACCES;
287
288        err = mnt_want_write(filp->f_path.mnt);
289        if (err)
290            return err;
291        /*
292         * inode_mutex prevent write and truncate on the file.
293         * Read still goes through. We take i_data_sem in
294         * ext4_ext_swap_inode_data before we switch the
295         * inode format to prevent read.
296         */
297        mutex_lock(&(inode->i_mutex));
298        err = ext4_ext_migrate(inode);
299        mutex_unlock(&(inode->i_mutex));
300        mnt_drop_write(filp->f_path.mnt);
301        return err;
302    }
303
304    case EXT4_IOC_ALLOC_DA_BLKS:
305    {
306        int err;
307        if (!is_owner_or_cap(inode))
308            return -EACCES;
309
310        err = mnt_want_write(filp->f_path.mnt);
311        if (err)
312            return err;
313        err = ext4_alloc_da_blocks(inode);
314        mnt_drop_write(filp->f_path.mnt);
315        return err;
316    }
317
318    default:
319        return -ENOTTY;
320    }
321}
322
323#ifdef CONFIG_COMPAT
324long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
325{
326    /* These are just misnamed, they actually get/put from/to user an int */
327    switch (cmd) {
328    case EXT4_IOC32_GETFLAGS:
329        cmd = EXT4_IOC_GETFLAGS;
330        break;
331    case EXT4_IOC32_SETFLAGS:
332        cmd = EXT4_IOC_SETFLAGS;
333        break;
334    case EXT4_IOC32_GETVERSION:
335        cmd = EXT4_IOC_GETVERSION;
336        break;
337    case EXT4_IOC32_SETVERSION:
338        cmd = EXT4_IOC_SETVERSION;
339        break;
340    case EXT4_IOC32_GROUP_EXTEND:
341        cmd = EXT4_IOC_GROUP_EXTEND;
342        break;
343    case EXT4_IOC32_GETVERSION_OLD:
344        cmd = EXT4_IOC_GETVERSION_OLD;
345        break;
346    case EXT4_IOC32_SETVERSION_OLD:
347        cmd = EXT4_IOC_SETVERSION_OLD;
348        break;
349#ifdef CONFIG_JBD2_DEBUG
350    case EXT4_IOC32_WAIT_FOR_READONLY:
351        cmd = EXT4_IOC_WAIT_FOR_READONLY;
352        break;
353#endif
354    case EXT4_IOC32_GETRSVSZ:
355        cmd = EXT4_IOC_GETRSVSZ;
356        break;
357    case EXT4_IOC32_SETRSVSZ:
358        cmd = EXT4_IOC_SETRSVSZ;
359        break;
360    case EXT4_IOC_GROUP_ADD:
361        break;
362    default:
363        return -ENOIOCTLCMD;
364    }
365    return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
366}
367#endif
368

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