PM / Hibernate: Make snapshot_release() restore GFP mask
[linux-2.6.git] / kernel / power / user.c
1 /*
2  * linux/kernel/power/user.c
3  *
4  * This file provides the user space interface for software suspend/resume.
5  *
6  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
7  *
8  * This file is released under the GPLv2.
9  *
10  */
11
12 #include <linux/suspend.h>
13 #include <linux/syscalls.h>
14 #include <linux/reboot.h>
15 #include <linux/string.h>
16 #include <linux/device.h>
17 #include <linux/miscdevice.h>
18 #include <linux/mm.h>
19 #include <linux/swap.h>
20 #include <linux/swapops.h>
21 #include <linux/pm.h>
22 #include <linux/fs.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
25 #include <linux/freezer.h>
26 #include <scsi/scsi_scan.h>
27
28 #include <asm/uaccess.h>
29
30 #include "power.h"
31
32 /*
33  * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34  * will be removed in the future.  They are only preserved here for
35  * compatibility with existing userland utilities.
36  */
37 #define SNAPSHOT_SET_SWAP_FILE  _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
38 #define SNAPSHOT_PMOPS          _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
39
40 #define PMOPS_PREPARE   1
41 #define PMOPS_ENTER     2
42 #define PMOPS_FINISH    3
43
44 /*
45  * NOTE: The following ioctl definitions are wrong and have been replaced with
46  * correct ones.  They are only preserved here for compatibility with existing
47  * userland utilities and will be removed in the future.
48  */
49 #define SNAPSHOT_ATOMIC_SNAPSHOT        _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50 #define SNAPSHOT_SET_IMAGE_SIZE         _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51 #define SNAPSHOT_AVAIL_SWAP             _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52 #define SNAPSHOT_GET_SWAP_PAGE          _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
53
54
55 #define SNAPSHOT_MINOR  231
56
57 static struct snapshot_data {
58         struct snapshot_handle handle;
59         int swap;
60         int mode;
61         char frozen;
62         char ready;
63         char platform_support;
64 } snapshot_state;
65
66 atomic_t snapshot_device_available = ATOMIC_INIT(1);
67
68 static int snapshot_open(struct inode *inode, struct file *filp)
69 {
70         struct snapshot_data *data;
71         int error;
72
73         mutex_lock(&pm_mutex);
74
75         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
76                 error = -EBUSY;
77                 goto Unlock;
78         }
79
80         if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
81                 atomic_inc(&snapshot_device_available);
82                 error = -ENOSYS;
83                 goto Unlock;
84         }
85         if(create_basic_memory_bitmaps()) {
86                 atomic_inc(&snapshot_device_available);
87                 error = -ENOMEM;
88                 goto Unlock;
89         }
90         nonseekable_open(inode, filp);
91         data = &snapshot_state;
92         filp->private_data = data;
93         memset(&data->handle, 0, sizeof(struct snapshot_handle));
94         if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
95                 /* Hibernating.  The image device should be accessible. */
96                 data->swap = swsusp_resume_device ?
97                         swap_type_of(swsusp_resume_device, 0, NULL) : -1;
98                 data->mode = O_RDONLY;
99                 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
100                 if (error)
101                         pm_notifier_call_chain(PM_POST_HIBERNATION);
102         } else {
103                 /*
104                  * Resuming.  We may need to wait for the image device to
105                  * appear.
106                  */
107                 wait_for_device_probe();
108                 scsi_complete_async_scans();
109
110                 data->swap = -1;
111                 data->mode = O_WRONLY;
112                 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
113                 if (error)
114                         pm_notifier_call_chain(PM_POST_RESTORE);
115         }
116         if (error)
117                 atomic_inc(&snapshot_device_available);
118         data->frozen = 0;
119         data->ready = 0;
120         data->platform_support = 0;
121
122  Unlock:
123         mutex_unlock(&pm_mutex);
124
125         return error;
126 }
127
128 static int snapshot_release(struct inode *inode, struct file *filp)
129 {
130         struct snapshot_data *data;
131
132         mutex_lock(&pm_mutex);
133
134         swsusp_free();
135         free_basic_memory_bitmaps();
136         data = filp->private_data;
137         free_all_swap_pages(data->swap);
138         if (data->frozen) {
139                 pm_restore_gfp_mask();
140                 thaw_processes();
141         }
142         pm_notifier_call_chain(data->mode == O_RDONLY ?
143                         PM_POST_HIBERNATION : PM_POST_RESTORE);
144         atomic_inc(&snapshot_device_available);
145
146         mutex_unlock(&pm_mutex);
147
148         return 0;
149 }
150
151 static ssize_t snapshot_read(struct file *filp, char __user *buf,
152                              size_t count, loff_t *offp)
153 {
154         struct snapshot_data *data;
155         ssize_t res;
156         loff_t pg_offp = *offp & ~PAGE_MASK;
157
158         mutex_lock(&pm_mutex);
159
160         data = filp->private_data;
161         if (!data->ready) {
162                 res = -ENODATA;
163                 goto Unlock;
164         }
165         if (!pg_offp) { /* on page boundary? */
166                 res = snapshot_read_next(&data->handle);
167                 if (res <= 0)
168                         goto Unlock;
169         } else {
170                 res = PAGE_SIZE - pg_offp;
171         }
172
173         res = simple_read_from_buffer(buf, count, &pg_offp,
174                         data_of(data->handle), res);
175         if (res > 0)
176                 *offp += res;
177
178  Unlock:
179         mutex_unlock(&pm_mutex);
180
181         return res;
182 }
183
184 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
185                               size_t count, loff_t *offp)
186 {
187         struct snapshot_data *data;
188         ssize_t res;
189         loff_t pg_offp = *offp & ~PAGE_MASK;
190
191         mutex_lock(&pm_mutex);
192
193         data = filp->private_data;
194
195         if (!pg_offp) {
196                 res = snapshot_write_next(&data->handle);
197                 if (res <= 0)
198                         goto unlock;
199         } else {
200                 res = PAGE_SIZE - pg_offp;
201         }
202
203         res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
204                         buf, count);
205         if (res > 0)
206                 *offp += res;
207 unlock:
208         mutex_unlock(&pm_mutex);
209
210         return res;
211 }
212
213 static void snapshot_deprecated_ioctl(unsigned int cmd)
214 {
215         if (printk_ratelimit())
216                 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
217                                 "be removed soon, update your suspend-to-disk "
218                                 "utilities\n",
219                                 __builtin_return_address(0), cmd);
220 }
221
222 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
223                                                         unsigned long arg)
224 {
225         int error = 0;
226         struct snapshot_data *data;
227         loff_t size;
228         sector_t offset;
229
230         if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
231                 return -ENOTTY;
232         if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
233                 return -ENOTTY;
234         if (!capable(CAP_SYS_ADMIN))
235                 return -EPERM;
236
237         if (!mutex_trylock(&pm_mutex))
238                 return -EBUSY;
239
240         data = filp->private_data;
241
242         switch (cmd) {
243
244         case SNAPSHOT_FREEZE:
245                 if (data->frozen)
246                         break;
247
248                 printk("Syncing filesystems ... ");
249                 sys_sync();
250                 printk("done.\n");
251
252                 error = usermodehelper_disable();
253                 if (error)
254                         break;
255
256                 error = freeze_processes();
257                 if (error) {
258                         thaw_processes();
259                         usermodehelper_enable();
260                 }
261                 if (!error)
262                         data->frozen = 1;
263                 break;
264
265         case SNAPSHOT_UNFREEZE:
266                 if (!data->frozen || data->ready)
267                         break;
268                 pm_restore_gfp_mask();
269                 thaw_processes();
270                 usermodehelper_enable();
271                 data->frozen = 0;
272                 break;
273
274         case SNAPSHOT_ATOMIC_SNAPSHOT:
275                 snapshot_deprecated_ioctl(cmd);
276         case SNAPSHOT_CREATE_IMAGE:
277                 if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
278                         error = -EPERM;
279                         break;
280                 }
281                 pm_restore_gfp_mask();
282                 error = hibernation_snapshot(data->platform_support);
283                 if (!error)
284                         error = put_user(in_suspend, (int __user *)arg);
285                 if (!error)
286                         data->ready = 1;
287                 break;
288
289         case SNAPSHOT_ATOMIC_RESTORE:
290                 snapshot_write_finalize(&data->handle);
291                 if (data->mode != O_WRONLY || !data->frozen ||
292                     !snapshot_image_loaded(&data->handle)) {
293                         error = -EPERM;
294                         break;
295                 }
296                 error = hibernation_restore(data->platform_support);
297                 break;
298
299         case SNAPSHOT_FREE:
300                 swsusp_free();
301                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
302                 data->ready = 0;
303                 break;
304
305         case SNAPSHOT_SET_IMAGE_SIZE:
306                 snapshot_deprecated_ioctl(cmd);
307         case SNAPSHOT_PREF_IMAGE_SIZE:
308                 image_size = arg;
309                 break;
310
311         case SNAPSHOT_GET_IMAGE_SIZE:
312                 if (!data->ready) {
313                         error = -ENODATA;
314                         break;
315                 }
316                 size = snapshot_get_image_size();
317                 size <<= PAGE_SHIFT;
318                 error = put_user(size, (loff_t __user *)arg);
319                 break;
320
321         case SNAPSHOT_AVAIL_SWAP:
322                 snapshot_deprecated_ioctl(cmd);
323         case SNAPSHOT_AVAIL_SWAP_SIZE:
324                 size = count_swap_pages(data->swap, 1);
325                 size <<= PAGE_SHIFT;
326                 error = put_user(size, (loff_t __user *)arg);
327                 break;
328
329         case SNAPSHOT_GET_SWAP_PAGE:
330                 snapshot_deprecated_ioctl(cmd);
331         case SNAPSHOT_ALLOC_SWAP_PAGE:
332                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
333                         error = -ENODEV;
334                         break;
335                 }
336                 offset = alloc_swapdev_block(data->swap);
337                 if (offset) {
338                         offset <<= PAGE_SHIFT;
339                         error = put_user(offset, (loff_t __user *)arg);
340                 } else {
341                         error = -ENOSPC;
342                 }
343                 break;
344
345         case SNAPSHOT_FREE_SWAP_PAGES:
346                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
347                         error = -ENODEV;
348                         break;
349                 }
350                 free_all_swap_pages(data->swap);
351                 break;
352
353         case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
354                 snapshot_deprecated_ioctl(cmd);
355                 if (!swsusp_swap_in_use()) {
356                         /*
357                          * User space encodes device types as two-byte values,
358                          * so we need to recode them
359                          */
360                         if (old_decode_dev(arg)) {
361                                 data->swap = swap_type_of(old_decode_dev(arg),
362                                                         0, NULL);
363                                 if (data->swap < 0)
364                                         error = -ENODEV;
365                         } else {
366                                 data->swap = -1;
367                                 error = -EINVAL;
368                         }
369                 } else {
370                         error = -EPERM;
371                 }
372                 break;
373
374         case SNAPSHOT_S2RAM:
375                 if (!data->frozen) {
376                         error = -EPERM;
377                         break;
378                 }
379                 /*
380                  * Tasks are frozen and the notifiers have been called with
381                  * PM_HIBERNATION_PREPARE
382                  */
383                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
384                 break;
385
386         case SNAPSHOT_PLATFORM_SUPPORT:
387                 data->platform_support = !!arg;
388                 break;
389
390         case SNAPSHOT_POWER_OFF:
391                 if (data->platform_support)
392                         error = hibernation_platform_enter();
393                 break;
394
395         case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
396                 snapshot_deprecated_ioctl(cmd);
397                 error = -EINVAL;
398
399                 switch (arg) {
400
401                 case PMOPS_PREPARE:
402                         data->platform_support = 1;
403                         error = 0;
404                         break;
405
406                 case PMOPS_ENTER:
407                         if (data->platform_support)
408                                 error = hibernation_platform_enter();
409                         break;
410
411                 case PMOPS_FINISH:
412                         if (data->platform_support)
413                                 error = 0;
414                         break;
415
416                 default:
417                         printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
418
419                 }
420                 break;
421
422         case SNAPSHOT_SET_SWAP_AREA:
423                 if (swsusp_swap_in_use()) {
424                         error = -EPERM;
425                 } else {
426                         struct resume_swap_area swap_area;
427                         dev_t swdev;
428
429                         error = copy_from_user(&swap_area, (void __user *)arg,
430                                         sizeof(struct resume_swap_area));
431                         if (error) {
432                                 error = -EFAULT;
433                                 break;
434                         }
435
436                         /*
437                          * User space encodes device types as two-byte values,
438                          * so we need to recode them
439                          */
440                         swdev = new_decode_dev(swap_area.dev);
441                         if (swdev) {
442                                 offset = swap_area.offset;
443                                 data->swap = swap_type_of(swdev, offset, NULL);
444                                 if (data->swap < 0)
445                                         error = -ENODEV;
446                         } else {
447                                 data->swap = -1;
448                                 error = -EINVAL;
449                         }
450                 }
451                 break;
452
453         default:
454                 error = -ENOTTY;
455
456         }
457
458         mutex_unlock(&pm_mutex);
459
460         return error;
461 }
462
463 static const struct file_operations snapshot_fops = {
464         .open = snapshot_open,
465         .release = snapshot_release,
466         .read = snapshot_read,
467         .write = snapshot_write,
468         .llseek = no_llseek,
469         .unlocked_ioctl = snapshot_ioctl,
470 };
471
472 static struct miscdevice snapshot_device = {
473         .minor = SNAPSHOT_MINOR,
474         .name = "snapshot",
475         .fops = &snapshot_fops,
476 };
477
478 static int __init snapshot_device_init(void)
479 {
480         return misc_register(&snapshot_device);
481 };
482
483 device_initcall(snapshot_device_init);