2 * Copyright (c) International Business Machines Corp., 2006
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 * Author: Artem Bityutskiy (Битюцкий Артём)
22 * This file includes implementation of UBI character device operations.
24 * There are two kinds of character devices in UBI: UBI character devices and
25 * UBI volume character devices. UBI character devices allow users to
26 * manipulate whole volumes: create, remove, and re-size them. Volume character
27 * devices provide volume I/O capabilities.
29 * Major and minor numbers are assigned dynamically to both UBI and volume
32 * Well, there is the third kind of character devices - the UBI control
33 * character device, which allows to manipulate by UBI devices - create and
34 * delete them. In other words, it is used for attaching and detaching MTD
38 #include <linux/module.h>
39 #include <linux/stat.h>
40 #include <linux/ioctl.h>
41 #include <linux/capability.h>
42 #include <linux/smp_lock.h>
43 #include <mtd/ubi-user.h>
44 #include <asm/uaccess.h>
45 #include <asm/div64.h>
49 * get_exclusive - get exclusive access to an UBI volume.
50 * @desc: volume descriptor
52 * This function changes UBI volume open mode to "exclusive". Returns previous
53 * mode value (positive integer) in case of success and a negative error code
56 static int get_exclusive(struct ubi_volume_desc
*desc
)
59 struct ubi_volume
*vol
= desc
->vol
;
61 spin_lock(&vol
->ubi
->volumes_lock
);
62 users
= vol
->readers
+ vol
->writers
+ vol
->exclusive
;
63 ubi_assert(users
> 0);
65 dbg_err("%d users for volume %d", users
, vol
->vol_id
);
68 vol
->readers
= vol
->writers
= 0;
71 desc
->mode
= UBI_EXCLUSIVE
;
73 spin_unlock(&vol
->ubi
->volumes_lock
);
79 * revoke_exclusive - revoke exclusive mode.
80 * @desc: volume descriptor
81 * @mode: new mode to switch to
83 static void revoke_exclusive(struct ubi_volume_desc
*desc
, int mode
)
85 struct ubi_volume
*vol
= desc
->vol
;
87 spin_lock(&vol
->ubi
->volumes_lock
);
88 ubi_assert(vol
->readers
== 0 && vol
->writers
== 0);
89 ubi_assert(vol
->exclusive
== 1 && desc
->mode
== UBI_EXCLUSIVE
);
91 if (mode
== UBI_READONLY
)
93 else if (mode
== UBI_READWRITE
)
97 spin_unlock(&vol
->ubi
->volumes_lock
);
102 static int vol_cdev_open(struct inode
*inode
, struct file
*file
)
104 struct ubi_volume_desc
*desc
;
105 int vol_id
= iminor(inode
) - 1, mode
, ubi_num
;
108 ubi_num
= ubi_major2num(imajor(inode
));
114 if (file
->f_mode
& FMODE_WRITE
)
115 mode
= UBI_READWRITE
;
119 dbg_msg("open volume %d, mode %d", vol_id
, mode
);
121 desc
= ubi_open_volume(ubi_num
, vol_id
, mode
);
124 return PTR_ERR(desc
);
126 file
->private_data
= desc
;
130 static int vol_cdev_release(struct inode
*inode
, struct file
*file
)
132 struct ubi_volume_desc
*desc
= file
->private_data
;
133 struct ubi_volume
*vol
= desc
->vol
;
135 dbg_msg("release volume %d, mode %d", vol
->vol_id
, desc
->mode
);
138 ubi_warn("update of volume %d not finished, volume is damaged",
140 ubi_assert(!vol
->changing_leb
);
143 } else if (vol
->changing_leb
) {
144 dbg_msg("only %lld of %lld bytes received for atomic LEB change"
145 " for volume %d:%d, cancel", vol
->upd_received
,
146 vol
->upd_bytes
, vol
->ubi
->ubi_num
, vol
->vol_id
);
147 vol
->changing_leb
= 0;
151 ubi_close_volume(desc
);
155 static loff_t
vol_cdev_llseek(struct file
*file
, loff_t offset
, int origin
)
157 struct ubi_volume_desc
*desc
= file
->private_data
;
158 struct ubi_volume
*vol
= desc
->vol
;
162 /* Update is in progress, seeking is prohibited */
168 case 0: /* SEEK_SET */
171 case 1: /* SEEK_CUR */
172 new_offset
= file
->f_pos
+ offset
;
174 case 2: /* SEEK_END */
175 new_offset
= vol
->used_bytes
+ offset
;
181 if (new_offset
< 0 || new_offset
> vol
->used_bytes
) {
182 dbg_err("bad seek %lld", new_offset
);
186 dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
187 vol
->vol_id
, offset
, origin
, new_offset
);
189 file
->f_pos
= new_offset
;
193 static ssize_t
vol_cdev_read(struct file
*file
, __user
char *buf
, size_t count
,
196 struct ubi_volume_desc
*desc
= file
->private_data
;
197 struct ubi_volume
*vol
= desc
->vol
;
198 struct ubi_device
*ubi
= vol
->ubi
;
199 int err
, lnum
, off
, len
, tbuf_size
;
200 size_t count_save
= count
;
204 dbg_msg("read %zd bytes from offset %lld of volume %d",
205 count
, *offp
, vol
->vol_id
);
211 if (vol
->upd_marker
) {
212 dbg_err("damaged volume, update marker is set");
215 if (*offp
== vol
->used_bytes
|| count
== 0)
219 dbg_msg("read from corrupted volume %d", vol
->vol_id
);
221 if (*offp
+ count
> vol
->used_bytes
)
222 count_save
= count
= vol
->used_bytes
- *offp
;
224 tbuf_size
= vol
->usable_leb_size
;
225 if (count
< tbuf_size
)
226 tbuf_size
= ALIGN(count
, ubi
->min_io_size
);
227 tbuf
= vmalloc(tbuf_size
);
231 len
= count
> tbuf_size
? tbuf_size
: count
;
234 off
= do_div(tmp
, vol
->usable_leb_size
);
240 if (off
+ len
>= vol
->usable_leb_size
)
241 len
= vol
->usable_leb_size
- off
;
243 err
= ubi_eba_read_leb(ubi
, vol
, lnum
, tbuf
, off
, len
, 0);
248 if (off
== vol
->usable_leb_size
) {
250 off
-= vol
->usable_leb_size
;
256 err
= copy_to_user(buf
, tbuf
, len
);
263 len
= count
> tbuf_size
? tbuf_size
: count
;
267 return err
? err
: count_save
- count
;
270 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
273 * This function allows to directly write to dynamic UBI volumes, without
274 * issuing the volume update operation. Available only as a debugging feature.
275 * Very useful for testing UBI.
277 static ssize_t
vol_cdev_direct_write(struct file
*file
, const char __user
*buf
,
278 size_t count
, loff_t
*offp
)
280 struct ubi_volume_desc
*desc
= file
->private_data
;
281 struct ubi_volume
*vol
= desc
->vol
;
282 struct ubi_device
*ubi
= vol
->ubi
;
283 int lnum
, off
, len
, tbuf_size
, err
= 0;
284 size_t count_save
= count
;
288 dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
289 count
, *offp
, vol
->vol_id
);
291 if (vol
->vol_type
== UBI_STATIC_VOLUME
)
295 off
= do_div(tmp
, vol
->usable_leb_size
);
298 if (off
% ubi
->min_io_size
) {
299 dbg_err("unaligned position");
303 if (*offp
+ count
> vol
->used_bytes
)
304 count_save
= count
= vol
->used_bytes
- *offp
;
306 /* We can write only in fractions of the minimum I/O unit */
307 if (count
% ubi
->min_io_size
) {
308 dbg_err("unaligned write length");
312 tbuf_size
= vol
->usable_leb_size
;
313 if (count
< tbuf_size
)
314 tbuf_size
= ALIGN(count
, ubi
->min_io_size
);
315 tbuf
= vmalloc(tbuf_size
);
319 len
= count
> tbuf_size
? tbuf_size
: count
;
324 if (off
+ len
>= vol
->usable_leb_size
)
325 len
= vol
->usable_leb_size
- off
;
327 err
= copy_from_user(tbuf
, buf
, len
);
333 err
= ubi_eba_write_leb(ubi
, vol
, lnum
, tbuf
, off
, len
,
339 if (off
== vol
->usable_leb_size
) {
341 off
-= vol
->usable_leb_size
;
347 len
= count
> tbuf_size
? tbuf_size
: count
;
351 return err
? err
: count_save
- count
;
355 #define vol_cdev_direct_write(file, buf, count, offp) -EPERM
356 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
358 static ssize_t
vol_cdev_write(struct file
*file
, const char __user
*buf
,
359 size_t count
, loff_t
*offp
)
362 struct ubi_volume_desc
*desc
= file
->private_data
;
363 struct ubi_volume
*vol
= desc
->vol
;
364 struct ubi_device
*ubi
= vol
->ubi
;
366 if (!vol
->updating
&& !vol
->changing_leb
)
367 return vol_cdev_direct_write(file
, buf
, count
, offp
);
370 err
= ubi_more_update_data(ubi
, vol
, buf
, count
);
372 err
= ubi_more_leb_change_data(ubi
, vol
, buf
, count
);
375 ubi_err("cannot accept more %zd bytes of data, error %d",
382 * The operation is finished, @err contains number of actually
387 if (vol
->changing_leb
) {
388 revoke_exclusive(desc
, UBI_READWRITE
);
392 err
= ubi_check_volume(ubi
, vol
->vol_id
);
397 ubi_warn("volume %d on UBI device %d is corrupted",
398 vol
->vol_id
, ubi
->ubi_num
);
402 ubi_gluebi_updated(vol
);
403 revoke_exclusive(desc
, UBI_READWRITE
);
409 static int vol_cdev_ioctl(struct inode
*inode
, struct file
*file
,
410 unsigned int cmd
, unsigned long arg
)
413 struct ubi_volume_desc
*desc
= file
->private_data
;
414 struct ubi_volume
*vol
= desc
->vol
;
415 struct ubi_device
*ubi
= vol
->ubi
;
416 void __user
*argp
= (void __user
*)arg
;
419 /* Volume update command */
422 int64_t bytes
, rsvd_bytes
;
424 if (!capable(CAP_SYS_RESOURCE
)) {
429 err
= copy_from_user(&bytes
, argp
, sizeof(int64_t));
435 if (desc
->mode
== UBI_READONLY
) {
440 rsvd_bytes
= vol
->reserved_pebs
* (ubi
->leb_size
-vol
->data_pad
);
441 if (bytes
< 0 || bytes
> rsvd_bytes
) {
446 err
= get_exclusive(desc
);
450 err
= ubi_start_update(ubi
, vol
, bytes
);
452 revoke_exclusive(desc
, UBI_READWRITE
);
456 /* Atomic logical eraseblock change command */
459 struct ubi_leb_change_req req
;
461 err
= copy_from_user(&req
, argp
,
462 sizeof(struct ubi_leb_change_req
));
468 if (desc
->mode
== UBI_READONLY
||
469 vol
->vol_type
== UBI_STATIC_VOLUME
) {
474 /* Validate the request */
476 if (req
.lnum
< 0 || req
.lnum
>= vol
->reserved_pebs
||
477 req
.bytes
< 0 || req
.lnum
>= vol
->usable_leb_size
)
479 if (req
.dtype
!= UBI_LONGTERM
&& req
.dtype
!= UBI_SHORTTERM
&&
480 req
.dtype
!= UBI_UNKNOWN
)
483 err
= get_exclusive(desc
);
487 err
= ubi_start_leb_change(ubi
, vol
, &req
);
489 revoke_exclusive(desc
, UBI_READWRITE
);
493 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
494 /* Logical eraseblock erasure command */
499 err
= get_user(lnum
, (__user
int32_t *)argp
);
505 if (desc
->mode
== UBI_READONLY
||
506 vol
->vol_type
== UBI_STATIC_VOLUME
) {
511 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
) {
516 dbg_msg("erase LEB %d:%d", vol
->vol_id
, lnum
);
517 err
= ubi_eba_unmap_leb(ubi
, vol
, lnum
);
521 err
= ubi_wl_flush(ubi
);
535 * verify_mkvol_req - verify volume creation request.
536 * @ubi: UBI device description object
537 * @req: the request to check
539 * This function zero if the request is correct, and %-EINVAL if not.
541 static int verify_mkvol_req(const struct ubi_device
*ubi
,
542 const struct ubi_mkvol_req
*req
)
544 int n
, err
= -EINVAL
;
546 if (req
->bytes
< 0 || req
->alignment
< 0 || req
->vol_type
< 0 ||
550 if ((req
->vol_id
< 0 || req
->vol_id
>= ubi
->vtbl_slots
) &&
551 req
->vol_id
!= UBI_VOL_NUM_AUTO
)
554 if (req
->alignment
== 0)
560 if (req
->vol_type
!= UBI_DYNAMIC_VOLUME
&&
561 req
->vol_type
!= UBI_STATIC_VOLUME
)
564 if (req
->alignment
> ubi
->leb_size
)
567 n
= req
->alignment
% ubi
->min_io_size
;
568 if (req
->alignment
!= 1 && n
)
571 if (req
->name_len
> UBI_VOL_NAME_MAX
) {
579 dbg_err("bad volume creation request");
580 ubi_dbg_dump_mkvol_req(req
);
585 * verify_rsvol_req - verify volume re-size request.
586 * @ubi: UBI device description object
587 * @req: the request to check
589 * This function returns zero if the request is correct, and %-EINVAL if not.
591 static int verify_rsvol_req(const struct ubi_device
*ubi
,
592 const struct ubi_rsvol_req
*req
)
597 if (req
->vol_id
< 0 || req
->vol_id
>= ubi
->vtbl_slots
)
603 static int ubi_cdev_ioctl(struct inode
*inode
, struct file
*file
,
604 unsigned int cmd
, unsigned long arg
)
607 struct ubi_device
*ubi
;
608 struct ubi_volume_desc
*desc
;
609 void __user
*argp
= (void __user
*)arg
;
611 if (!capable(CAP_SYS_RESOURCE
))
614 ubi
= ubi_get_by_major(imajor(inode
));
619 /* Create volume command */
622 struct ubi_mkvol_req req
;
624 dbg_msg("create volume");
625 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_mkvol_req
));
631 err
= verify_mkvol_req(ubi
, &req
);
635 req
.name
[req
.name_len
] = '\0';
637 mutex_lock(&ubi
->volumes_mutex
);
638 err
= ubi_create_volume(ubi
, &req
);
639 mutex_unlock(&ubi
->volumes_mutex
);
643 err
= put_user(req
.vol_id
, (__user
int32_t *)argp
);
650 /* Remove volume command */
655 dbg_msg("remove volume");
656 err
= get_user(vol_id
, (__user
int32_t *)argp
);
662 desc
= ubi_open_volume(ubi
->ubi_num
, vol_id
, UBI_EXCLUSIVE
);
668 mutex_lock(&ubi
->volumes_mutex
);
669 err
= ubi_remove_volume(desc
);
670 mutex_unlock(&ubi
->volumes_mutex
);
673 * The volume is deleted (unless an error occurred), and the
674 * 'struct ubi_volume' object will be freed when
675 * 'ubi_close_volume()' will call 'put_device()'.
677 ubi_close_volume(desc
);
681 /* Re-size volume command */
686 struct ubi_rsvol_req req
;
688 dbg_msg("re-size volume");
689 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_rsvol_req
));
695 err
= verify_rsvol_req(ubi
, &req
);
699 desc
= ubi_open_volume(ubi
->ubi_num
, req
.vol_id
, UBI_EXCLUSIVE
);
706 pebs
= !!do_div(tmp
, desc
->vol
->usable_leb_size
);
709 mutex_lock(&ubi
->volumes_mutex
);
710 err
= ubi_resize_volume(desc
, pebs
);
711 mutex_unlock(&ubi
->volumes_mutex
);
712 ubi_close_volume(desc
);
725 static int ctrl_cdev_ioctl(struct inode
*inode
, struct file
*file
,
726 unsigned int cmd
, unsigned long arg
)
729 void __user
*argp
= (void __user
*)arg
;
731 if (!capable(CAP_SYS_RESOURCE
))
735 /* Attach an MTD device command */
738 struct ubi_attach_req req
;
739 struct mtd_info
*mtd
;
741 dbg_msg("attach MTD device");
742 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_attach_req
));
748 if (req
.mtd_num
< 0 ||
749 (req
.ubi_num
< 0 && req
.ubi_num
!= UBI_DEV_NUM_AUTO
)) {
754 mtd
= get_mtd_device(NULL
, req
.mtd_num
);
761 * Note, further request verification is done by
762 * 'ubi_attach_mtd_dev()'.
764 mutex_lock(&ubi_devices_mutex
);
765 err
= ubi_attach_mtd_dev(mtd
, req
.ubi_num
, req
.vid_hdr_offset
);
766 mutex_unlock(&ubi_devices_mutex
);
770 /* @err contains UBI device number */
771 err
= put_user(err
, (__user
int32_t *)argp
);
776 /* Detach an MTD device command */
781 dbg_msg("dettach MTD device");
782 err
= get_user(ubi_num
, (__user
int32_t *)argp
);
788 mutex_lock(&ubi_devices_mutex
);
789 err
= ubi_detach_mtd_dev(ubi_num
, 0);
790 mutex_unlock(&ubi_devices_mutex
);
802 /* UBI control character device operations */
803 struct file_operations ubi_ctrl_cdev_operations
= {
804 .ioctl
= ctrl_cdev_ioctl
,
805 .owner
= THIS_MODULE
,
808 /* UBI character device operations */
809 struct file_operations ubi_cdev_operations
= {
810 .owner
= THIS_MODULE
,
811 .ioctl
= ubi_cdev_ioctl
,
815 /* UBI volume character device operations */
816 struct file_operations ubi_vol_cdev_operations
= {
817 .owner
= THIS_MODULE
,
818 .open
= vol_cdev_open
,
819 .release
= vol_cdev_release
,
820 .llseek
= vol_cdev_llseek
,
821 .read
= vol_cdev_read
,
822 .write
= vol_cdev_write
,
823 .ioctl
= vol_cdev_ioctl
,