ext4: avoid unnecessary spinlock in critical POSIX ACL path
[deliverable/linux.git] / fs / ext4 / ioctl.c
CommitLineData
ac27a0ec 1/*
617ba13b 2 * linux/fs/ext4/ioctl.c
ac27a0ec
DK
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>
dab291af 11#include <linux/jbd2.h>
ac27a0ec 12#include <linux/capability.h>
ac27a0ec
DK
13#include <linux/time.h>
14#include <linux/compat.h>
15#include <linux/smp_lock.h>
42a74f20 16#include <linux/mount.h>
ac27a0ec 17#include <asm/uaccess.h>
3dcf5451
CH
18#include "ext4_jbd2.h"
19#include "ext4.h"
ac27a0ec 20
5cdd7b2d 21long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
ac27a0ec 22{
5cdd7b2d 23 struct inode *inode = filp->f_dentry->d_inode;
617ba13b 24 struct ext4_inode_info *ei = EXT4_I(inode);
ac27a0ec 25 unsigned int flags;
ac27a0ec 26
af5bc92d 27 ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
ac27a0ec
DK
28
29 switch (cmd) {
617ba13b 30 case EXT4_IOC_GETFLAGS:
ff9ddf7e 31 ext4_get_inode_flags(ei);
617ba13b 32 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
ac27a0ec 33 return put_user(flags, (int __user *) arg);
617ba13b 34 case EXT4_IOC_SETFLAGS: {
ac27a0ec 35 handle_t *handle = NULL;
4db46fc2 36 int err, migrate = 0;
617ba13b 37 struct ext4_iloc iloc;
ac27a0ec
DK
38 unsigned int oldflags;
39 unsigned int jflag;
40
3bd858ab 41 if (!is_owner_or_cap(inode))
ac27a0ec
DK
42 return -EACCES;
43
44 if (get_user(flags, (int __user *) arg))
45 return -EFAULT;
46
42a74f20
DH
47 err = mnt_want_write(filp->f_path.mnt);
48 if (err)
49 return err;
50
2dc6b0d4 51 flags = ext4_mask_flags(inode->i_mode, flags);
ac27a0ec 52
42a74f20 53 err = -EPERM;
ac27a0ec 54 mutex_lock(&inode->i_mutex);
e47776a0 55 /* Is it quota file? Do not allow user to mess with it */
42a74f20
DH
56 if (IS_NOQUOTA(inode))
57 goto flags_out;
58
ac27a0ec
DK
59 oldflags = ei->i_flags;
60
61 /* The JOURNAL_DATA flag is modifiable only by root */
617ba13b 62 jflag = flags & EXT4_JOURNAL_DATA_FL;
ac27a0ec
DK
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 */
617ba13b 70 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
42a74f20
DH
71 if (!capable(CAP_LINUX_IMMUTABLE))
72 goto flags_out;
ac27a0ec
DK
73 }
74
75 /*
76 * The JOURNAL_DATA flag can only be changed by
77 * the relevant capability.
78 */
617ba13b 79 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
42a74f20
DH
80 if (!capable(CAP_SYS_RESOURCE))
81 goto flags_out;
ac27a0ec 82 }
4db46fc2
AK
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 }
ac27a0ec 94
617ba13b 95 handle = ext4_journal_start(inode, 1);
ac27a0ec 96 if (IS_ERR(handle)) {
42a74f20
DH
97 err = PTR_ERR(handle);
98 goto flags_out;
ac27a0ec
DK
99 }
100 if (IS_SYNC(inode))
0390131b 101 ext4_handle_sync(handle);
617ba13b 102 err = ext4_reserve_inode_write(handle, inode, &iloc);
ac27a0ec
DK
103 if (err)
104 goto flags_err;
105
617ba13b
MC
106 flags = flags & EXT4_FL_USER_MODIFIABLE;
107 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
ac27a0ec
DK
108 ei->i_flags = flags;
109
617ba13b 110 ext4_set_inode_flags(inode);
ef7f3835 111 inode->i_ctime = ext4_current_time(inode);
ac27a0ec 112
617ba13b 113 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
ac27a0ec 114flags_err:
617ba13b 115 ext4_journal_stop(handle);
42a74f20
DH
116 if (err)
117 goto flags_out;
ac27a0ec 118
617ba13b
MC
119 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
120 err = ext4_change_inode_journal_flag(inode, jflag);
4db46fc2
AK
121 if (err)
122 goto flags_out;
123 if (migrate)
124 err = ext4_ext_migrate(inode);
42a74f20 125flags_out:
ac27a0ec 126 mutex_unlock(&inode->i_mutex);
42a74f20 127 mnt_drop_write(filp->f_path.mnt);
ac27a0ec
DK
128 return err;
129 }
617ba13b
MC
130 case EXT4_IOC_GETVERSION:
131 case EXT4_IOC_GETVERSION_OLD:
ac27a0ec 132 return put_user(inode->i_generation, (int __user *) arg);
617ba13b
MC
133 case EXT4_IOC_SETVERSION:
134 case EXT4_IOC_SETVERSION_OLD: {
ac27a0ec 135 handle_t *handle;
617ba13b 136 struct ext4_iloc iloc;
ac27a0ec
DK
137 __u32 generation;
138 int err;
139
3bd858ab 140 if (!is_owner_or_cap(inode))
ac27a0ec 141 return -EPERM;
42a74f20
DH
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 }
ac27a0ec 150
617ba13b 151 handle = ext4_journal_start(inode, 1);
42a74f20
DH
152 if (IS_ERR(handle)) {
153 err = PTR_ERR(handle);
154 goto setversion_out;
155 }
617ba13b 156 err = ext4_reserve_inode_write(handle, inode, &iloc);
ac27a0ec 157 if (err == 0) {
ef7f3835 158 inode->i_ctime = ext4_current_time(inode);
ac27a0ec 159 inode->i_generation = generation;
617ba13b 160 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
ac27a0ec 161 }
617ba13b 162 ext4_journal_stop(handle);
42a74f20
DH
163setversion_out:
164 mnt_drop_write(filp->f_path.mnt);
ac27a0ec
DK
165 return err;
166 }
e23291b9 167#ifdef CONFIG_JBD2_DEBUG
617ba13b 168 case EXT4_IOC_WAIT_FOR_READONLY:
ac27a0ec
DK
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);
617ba13b
MC
182 add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
183 if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
ac27a0ec
DK
184 schedule();
185 ret = 1;
186 }
617ba13b 187 remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
ac27a0ec
DK
188 return ret;
189 }
190#endif
617ba13b
MC
191 case EXT4_IOC_GROUP_EXTEND: {
192 ext4_fsblk_t n_blocks_count;
ac27a0ec 193 struct super_block *sb = inode->i_sb;
7ffe1ea8 194 int err, err2;
ac27a0ec
DK
195
196 if (!capable(CAP_SYS_RESOURCE))
197 return -EPERM;
198
ac27a0ec
DK
199 if (get_user(n_blocks_count, (__u32 __user *)arg))
200 return -EFAULT;
201
42a74f20
DH
202 err = mnt_want_write(filp->f_path.mnt);
203 if (err)
204 return err;
205
617ba13b 206 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
dab291af 207 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
7ffe1ea8 208 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
dab291af 209 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
7ffe1ea8
HK
210 if (err == 0)
211 err = err2;
42a74f20 212 mnt_drop_write(filp->f_path.mnt);
ac27a0ec
DK
213
214 return err;
215 }
617ba13b
MC
216 case EXT4_IOC_GROUP_ADD: {
217 struct ext4_new_group_data input;
ac27a0ec 218 struct super_block *sb = inode->i_sb;
7ffe1ea8 219 int err, err2;
ac27a0ec
DK
220
221 if (!capable(CAP_SYS_RESOURCE))
222 return -EPERM;
223
617ba13b 224 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
ac27a0ec
DK
225 sizeof(input)))
226 return -EFAULT;
227
42a74f20
DH
228 err = mnt_want_write(filp->f_path.mnt);
229 if (err)
230 return err;
231
617ba13b 232 err = ext4_group_add(sb, &input);
dab291af 233 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
7ffe1ea8 234 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
dab291af 235 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
7ffe1ea8
HK
236 if (err == 0)
237 err = err2;
42a74f20 238 mnt_drop_write(filp->f_path.mnt);
ac27a0ec
DK
239
240 return err;
241 }
242
c14c6fd5 243 case EXT4_IOC_MIGRATE:
2a43a878
AK
244 {
245 int err;
246 if (!is_owner_or_cap(inode))
247 return -EACCES;
248
249 err = mnt_want_write(filp->f_path.mnt);
250 if (err)
251 return err;
252 /*
253 * inode_mutex prevent write and truncate on the file.
254 * Read still goes through. We take i_data_sem in
255 * ext4_ext_swap_inode_data before we switch the
256 * inode format to prevent read.
257 */
258 mutex_lock(&(inode->i_mutex));
259 err = ext4_ext_migrate(inode);
260 mutex_unlock(&(inode->i_mutex));
261 mnt_drop_write(filp->f_path.mnt);
262 return err;
263 }
c14c6fd5 264
ccd2506b
TT
265 case EXT4_IOC_ALLOC_DA_BLKS:
266 {
267 int err;
268 if (!is_owner_or_cap(inode))
269 return -EACCES;
270
271 err = mnt_want_write(filp->f_path.mnt);
272 if (err)
273 return err;
274 err = ext4_alloc_da_blocks(inode);
275 mnt_drop_write(filp->f_path.mnt);
276 return err;
277 }
278
ac27a0ec
DK
279 default:
280 return -ENOTTY;
281 }
282}
283
284#ifdef CONFIG_COMPAT
617ba13b 285long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
ac27a0ec 286{
ac27a0ec
DK
287 /* These are just misnamed, they actually get/put from/to user an int */
288 switch (cmd) {
617ba13b
MC
289 case EXT4_IOC32_GETFLAGS:
290 cmd = EXT4_IOC_GETFLAGS;
ac27a0ec 291 break;
617ba13b
MC
292 case EXT4_IOC32_SETFLAGS:
293 cmd = EXT4_IOC_SETFLAGS;
ac27a0ec 294 break;
617ba13b
MC
295 case EXT4_IOC32_GETVERSION:
296 cmd = EXT4_IOC_GETVERSION;
ac27a0ec 297 break;
617ba13b
MC
298 case EXT4_IOC32_SETVERSION:
299 cmd = EXT4_IOC_SETVERSION;
ac27a0ec 300 break;
617ba13b
MC
301 case EXT4_IOC32_GROUP_EXTEND:
302 cmd = EXT4_IOC_GROUP_EXTEND;
ac27a0ec 303 break;
617ba13b
MC
304 case EXT4_IOC32_GETVERSION_OLD:
305 cmd = EXT4_IOC_GETVERSION_OLD;
ac27a0ec 306 break;
617ba13b
MC
307 case EXT4_IOC32_SETVERSION_OLD:
308 cmd = EXT4_IOC_SETVERSION_OLD;
ac27a0ec 309 break;
e23291b9 310#ifdef CONFIG_JBD2_DEBUG
617ba13b
MC
311 case EXT4_IOC32_WAIT_FOR_READONLY:
312 cmd = EXT4_IOC_WAIT_FOR_READONLY;
ac27a0ec
DK
313 break;
314#endif
617ba13b
MC
315 case EXT4_IOC32_GETRSVSZ:
316 cmd = EXT4_IOC_GETRSVSZ;
ac27a0ec 317 break;
617ba13b
MC
318 case EXT4_IOC32_SETRSVSZ:
319 cmd = EXT4_IOC_SETRSVSZ;
ac27a0ec 320 break;
617ba13b 321 case EXT4_IOC_GROUP_ADD:
ac27a0ec
DK
322 break;
323 default:
324 return -ENOIOCTLCMD;
325 }
5cdd7b2d 326 return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
ac27a0ec
DK
327}
328#endif
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