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/uaccess.h>
43 #include <linux/smp_lock.h>
44 #include <mtd/ubi-user.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
;
107 ubi_num
= ubi_major2num(imajor(inode
));
111 if (file
->f_mode
& FMODE_WRITE
)
112 mode
= UBI_READWRITE
;
116 dbg_gen("open volume %d, mode %d", vol_id
, mode
);
118 desc
= ubi_open_volume(ubi_num
, vol_id
, mode
);
120 return PTR_ERR(desc
);
122 file
->private_data
= desc
;
126 static int vol_cdev_release(struct inode
*inode
, struct file
*file
)
128 struct ubi_volume_desc
*desc
= file
->private_data
;
129 struct ubi_volume
*vol
= desc
->vol
;
131 dbg_gen("release volume %d, mode %d", vol
->vol_id
, desc
->mode
);
134 ubi_warn("update of volume %d not finished, volume is damaged",
136 ubi_assert(!vol
->changing_leb
);
139 } else if (vol
->changing_leb
) {
140 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
141 " for volume %d:%d, cancel", vol
->upd_received
,
142 vol
->upd_bytes
, vol
->ubi
->ubi_num
, vol
->vol_id
);
143 vol
->changing_leb
= 0;
147 ubi_close_volume(desc
);
151 static loff_t
vol_cdev_llseek(struct file
*file
, loff_t offset
, int origin
)
153 struct ubi_volume_desc
*desc
= file
->private_data
;
154 struct ubi_volume
*vol
= desc
->vol
;
158 /* Update is in progress, seeking is prohibited */
164 case 0: /* SEEK_SET */
167 case 1: /* SEEK_CUR */
168 new_offset
= file
->f_pos
+ offset
;
170 case 2: /* SEEK_END */
171 new_offset
= vol
->used_bytes
+ offset
;
177 if (new_offset
< 0 || new_offset
> vol
->used_bytes
) {
178 dbg_err("bad seek %lld", new_offset
);
182 dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
183 vol
->vol_id
, offset
, origin
, new_offset
);
185 file
->f_pos
= new_offset
;
189 static ssize_t
vol_cdev_read(struct file
*file
, __user
char *buf
, size_t count
,
192 struct ubi_volume_desc
*desc
= file
->private_data
;
193 struct ubi_volume
*vol
= desc
->vol
;
194 struct ubi_device
*ubi
= vol
->ubi
;
195 int err
, lnum
, off
, len
, tbuf_size
;
196 size_t count_save
= count
;
200 dbg_gen("read %zd bytes from offset %lld of volume %d",
201 count
, *offp
, vol
->vol_id
);
207 if (vol
->upd_marker
) {
208 dbg_err("damaged volume, update marker is set");
211 if (*offp
== vol
->used_bytes
|| count
== 0)
215 dbg_gen("read from corrupted volume %d", vol
->vol_id
);
217 if (*offp
+ count
> vol
->used_bytes
)
218 count_save
= count
= vol
->used_bytes
- *offp
;
220 tbuf_size
= vol
->usable_leb_size
;
221 if (count
< tbuf_size
)
222 tbuf_size
= ALIGN(count
, ubi
->min_io_size
);
223 tbuf
= vmalloc(tbuf_size
);
227 len
= count
> tbuf_size
? tbuf_size
: count
;
230 off
= do_div(tmp
, vol
->usable_leb_size
);
236 if (off
+ len
>= vol
->usable_leb_size
)
237 len
= vol
->usable_leb_size
- off
;
239 err
= ubi_eba_read_leb(ubi
, vol
, lnum
, tbuf
, off
, len
, 0);
244 if (off
== vol
->usable_leb_size
) {
246 off
-= vol
->usable_leb_size
;
252 err
= copy_to_user(buf
, tbuf
, len
);
259 len
= count
> tbuf_size
? tbuf_size
: count
;
263 return err
? err
: count_save
- count
;
266 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
269 * This function allows to directly write to dynamic UBI volumes, without
270 * issuing the volume update operation. Available only as a debugging feature.
271 * Very useful for testing UBI.
273 static ssize_t
vol_cdev_direct_write(struct file
*file
, const char __user
*buf
,
274 size_t count
, loff_t
*offp
)
276 struct ubi_volume_desc
*desc
= file
->private_data
;
277 struct ubi_volume
*vol
= desc
->vol
;
278 struct ubi_device
*ubi
= vol
->ubi
;
279 int lnum
, off
, len
, tbuf_size
, err
= 0;
280 size_t count_save
= count
;
284 dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
285 count
, *offp
, vol
->vol_id
);
287 if (vol
->vol_type
== UBI_STATIC_VOLUME
)
291 off
= do_div(tmp
, vol
->usable_leb_size
);
294 if (off
& (ubi
->min_io_size
- 1)) {
295 dbg_err("unaligned position");
299 if (*offp
+ count
> vol
->used_bytes
)
300 count_save
= count
= vol
->used_bytes
- *offp
;
302 /* We can write only in fractions of the minimum I/O unit */
303 if (count
& (ubi
->min_io_size
- 1)) {
304 dbg_err("unaligned write length");
308 tbuf_size
= vol
->usable_leb_size
;
309 if (count
< tbuf_size
)
310 tbuf_size
= ALIGN(count
, ubi
->min_io_size
);
311 tbuf
= vmalloc(tbuf_size
);
315 len
= count
> tbuf_size
? tbuf_size
: count
;
320 if (off
+ len
>= vol
->usable_leb_size
)
321 len
= vol
->usable_leb_size
- off
;
323 err
= copy_from_user(tbuf
, buf
, len
);
329 err
= ubi_eba_write_leb(ubi
, vol
, lnum
, tbuf
, off
, len
,
335 if (off
== vol
->usable_leb_size
) {
337 off
-= vol
->usable_leb_size
;
343 len
= count
> tbuf_size
? tbuf_size
: count
;
347 return err
? err
: count_save
- count
;
351 #define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
352 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
354 static ssize_t
vol_cdev_write(struct file
*file
, const char __user
*buf
,
355 size_t count
, loff_t
*offp
)
358 struct ubi_volume_desc
*desc
= file
->private_data
;
359 struct ubi_volume
*vol
= desc
->vol
;
360 struct ubi_device
*ubi
= vol
->ubi
;
362 if (!vol
->updating
&& !vol
->changing_leb
)
363 return vol_cdev_direct_write(file
, buf
, count
, offp
);
366 err
= ubi_more_update_data(ubi
, vol
, buf
, count
);
368 err
= ubi_more_leb_change_data(ubi
, vol
, buf
, count
);
371 ubi_err("cannot accept more %zd bytes of data, error %d",
378 * The operation is finished, @err contains number of actually
383 if (vol
->changing_leb
) {
384 revoke_exclusive(desc
, UBI_READWRITE
);
388 err
= ubi_check_volume(ubi
, vol
->vol_id
);
393 ubi_warn("volume %d on UBI device %d is corrupted",
394 vol
->vol_id
, ubi
->ubi_num
);
398 ubi_gluebi_updated(vol
);
399 revoke_exclusive(desc
, UBI_READWRITE
);
405 static int vol_cdev_ioctl(struct inode
*inode
, struct file
*file
,
406 unsigned int cmd
, unsigned long arg
)
409 struct ubi_volume_desc
*desc
= file
->private_data
;
410 struct ubi_volume
*vol
= desc
->vol
;
411 struct ubi_device
*ubi
= vol
->ubi
;
412 void __user
*argp
= (void __user
*)arg
;
415 /* Volume update command */
418 int64_t bytes
, rsvd_bytes
;
420 if (!capable(CAP_SYS_RESOURCE
)) {
425 err
= copy_from_user(&bytes
, argp
, sizeof(int64_t));
431 if (desc
->mode
== UBI_READONLY
) {
436 rsvd_bytes
= (long long)vol
->reserved_pebs
*
437 ubi
->leb_size
-vol
->data_pad
;
438 if (bytes
< 0 || bytes
> rsvd_bytes
) {
443 err
= get_exclusive(desc
);
447 err
= ubi_start_update(ubi
, vol
, bytes
);
449 revoke_exclusive(desc
, UBI_READWRITE
);
453 /* Atomic logical eraseblock change command */
456 struct ubi_leb_change_req req
;
458 err
= copy_from_user(&req
, argp
,
459 sizeof(struct ubi_leb_change_req
));
465 if (desc
->mode
== UBI_READONLY
||
466 vol
->vol_type
== UBI_STATIC_VOLUME
) {
471 /* Validate the request */
473 if (req
.lnum
< 0 || req
.lnum
>= vol
->reserved_pebs
||
474 req
.bytes
< 0 || req
.lnum
>= vol
->usable_leb_size
)
476 if (req
.dtype
!= UBI_LONGTERM
&& req
.dtype
!= UBI_SHORTTERM
&&
477 req
.dtype
!= UBI_UNKNOWN
)
480 err
= get_exclusive(desc
);
484 err
= ubi_start_leb_change(ubi
, vol
, &req
);
486 revoke_exclusive(desc
, UBI_READWRITE
);
490 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
491 /* Logical eraseblock erasure command */
496 err
= get_user(lnum
, (__user
int32_t *)argp
);
502 if (desc
->mode
== UBI_READONLY
||
503 vol
->vol_type
== UBI_STATIC_VOLUME
) {
508 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
) {
513 dbg_gen("erase LEB %d:%d", vol
->vol_id
, lnum
);
514 err
= ubi_eba_unmap_leb(ubi
, vol
, lnum
);
518 err
= ubi_wl_flush(ubi
);
532 * verify_mkvol_req - verify volume creation request.
533 * @ubi: UBI device description object
534 * @req: the request to check
536 * This function zero if the request is correct, and %-EINVAL if not.
538 static int verify_mkvol_req(const struct ubi_device
*ubi
,
539 const struct ubi_mkvol_req
*req
)
541 int n
, err
= -EINVAL
;
543 if (req
->bytes
< 0 || req
->alignment
< 0 || req
->vol_type
< 0 ||
547 if ((req
->vol_id
< 0 || req
->vol_id
>= ubi
->vtbl_slots
) &&
548 req
->vol_id
!= UBI_VOL_NUM_AUTO
)
551 if (req
->alignment
== 0)
557 if (req
->vol_type
!= UBI_DYNAMIC_VOLUME
&&
558 req
->vol_type
!= UBI_STATIC_VOLUME
)
561 if (req
->alignment
> ubi
->leb_size
)
564 n
= req
->alignment
& (ubi
->min_io_size
- 1);
565 if (req
->alignment
!= 1 && n
)
568 if (req
->name_len
> UBI_VOL_NAME_MAX
) {
573 n
= strnlen(req
->name
, req
->name_len
+ 1);
574 if (n
!= req
->name_len
)
580 dbg_err("bad volume creation request");
581 ubi_dbg_dump_mkvol_req(req
);
586 * verify_rsvol_req - verify volume re-size request.
587 * @ubi: UBI device description object
588 * @req: the request to check
590 * This function returns zero if the request is correct, and %-EINVAL if not.
592 static int verify_rsvol_req(const struct ubi_device
*ubi
,
593 const struct ubi_rsvol_req
*req
)
598 if (req
->vol_id
< 0 || req
->vol_id
>= ubi
->vtbl_slots
)
605 * rename_volumes - rename UBI volumes.
606 * @ubi: UBI device description object
607 * @req: volumes re-name request
609 * This is a helper function for the volume re-name IOCTL which validates the
610 * the request, opens the volume and calls corresponding volumes management
611 * function. Returns zero in case of success and a negative error code in case
614 static int rename_volumes(struct ubi_device
*ubi
,
615 struct ubi_rnvol_req
*req
)
618 struct list_head rename_list
;
619 struct ubi_rename_entry
*re
, *re1
;
621 if (req
->count
< 0 || req
->count
> UBI_MAX_RNVOL
)
627 /* Validate volume IDs and names in the request */
628 for (i
= 0; i
< req
->count
; i
++) {
629 if (req
->ents
[i
].vol_id
< 0 ||
630 req
->ents
[i
].vol_id
>= ubi
->vtbl_slots
)
632 if (req
->ents
[i
].name_len
< 0)
634 if (req
->ents
[i
].name_len
> UBI_VOL_NAME_MAX
)
635 return -ENAMETOOLONG
;
636 req
->ents
[i
].name
[req
->ents
[i
].name_len
] = '\0';
637 n
= strlen(req
->ents
[i
].name
);
638 if (n
!= req
->ents
[i
].name_len
)
642 /* Make sure volume IDs and names are unique */
643 for (i
= 0; i
< req
->count
- 1; i
++) {
644 for (n
= i
+ 1; n
< req
->count
; n
++) {
645 if (req
->ents
[i
].vol_id
== req
->ents
[n
].vol_id
) {
646 dbg_err("duplicated volume id %d",
647 req
->ents
[i
].vol_id
);
650 if (!strcmp(req
->ents
[i
].name
, req
->ents
[n
].name
)) {
651 dbg_err("duplicated volume name \"%s\"",
658 /* Create the re-name list */
659 INIT_LIST_HEAD(&rename_list
);
660 for (i
= 0; i
< req
->count
; i
++) {
661 int vol_id
= req
->ents
[i
].vol_id
;
662 int name_len
= req
->ents
[i
].name_len
;
663 const char *name
= req
->ents
[i
].name
;
665 re
= kzalloc(sizeof(struct ubi_rename_entry
), GFP_KERNEL
);
671 re
->desc
= ubi_open_volume(ubi
->ubi_num
, vol_id
, UBI_EXCLUSIVE
);
672 if (IS_ERR(re
->desc
)) {
673 err
= PTR_ERR(re
->desc
);
674 dbg_err("cannot open volume %d, error %d", vol_id
, err
);
679 /* Skip this re-naming if the name does not really change */
680 if (re
->desc
->vol
->name_len
== name_len
&&
681 !memcmp(re
->desc
->vol
->name
, name
, name_len
)) {
682 ubi_close_volume(re
->desc
);
687 re
->new_name_len
= name_len
;
688 memcpy(re
->new_name
, name
, name_len
);
689 list_add_tail(&re
->list
, &rename_list
);
690 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
691 vol_id
, re
->desc
->vol
->name
, name
);
694 if (list_empty(&rename_list
))
697 /* Find out the volumes which have to be removed */
698 list_for_each_entry(re
, &rename_list
, list
) {
699 struct ubi_volume_desc
*desc
;
700 int no_remove_needed
= 0;
703 * Volume @re->vol_id is going to be re-named to
704 * @re->new_name, while its current name is @name. If a volume
705 * with name @re->new_name currently exists, it has to be
706 * removed, unless it is also re-named in the request (@req).
708 list_for_each_entry(re1
, &rename_list
, list
) {
709 if (re
->new_name_len
== re1
->desc
->vol
->name_len
&&
710 !memcmp(re
->new_name
, re1
->desc
->vol
->name
,
711 re1
->desc
->vol
->name_len
)) {
712 no_remove_needed
= 1;
717 if (no_remove_needed
)
721 * It seems we need to remove volume with name @re->new_name,
724 desc
= ubi_open_volume_nm(ubi
->ubi_num
, re
->new_name
, UBI_EXCLUSIVE
);
728 /* Re-naming into a non-existing volume name */
731 /* The volume exists but busy, or an error occurred */
732 dbg_err("cannot open volume \"%s\", error %d",
737 re
= kzalloc(sizeof(struct ubi_rename_entry
), GFP_KERNEL
);
740 ubi_close_volume(desc
);
746 list_add(&re
->list
, &rename_list
);
747 dbg_msg("will remove volume %d, name \"%s\"",
748 re
->desc
->vol
->vol_id
, re
->desc
->vol
->name
);
751 mutex_lock(&ubi
->volumes_mutex
);
752 err
= ubi_rename_volumes(ubi
, &rename_list
);
753 mutex_unlock(&ubi
->volumes_mutex
);
756 list_for_each_entry_safe(re
, re1
, &rename_list
, list
) {
757 ubi_close_volume(re
->desc
);
764 static int ubi_cdev_ioctl(struct inode
*inode
, struct file
*file
,
765 unsigned int cmd
, unsigned long arg
)
768 struct ubi_device
*ubi
;
769 struct ubi_volume_desc
*desc
;
770 void __user
*argp
= (void __user
*)arg
;
772 if (!capable(CAP_SYS_RESOURCE
))
775 ubi
= ubi_get_by_major(imajor(inode
));
780 /* Create volume command */
783 struct ubi_mkvol_req req
;
785 dbg_gen("create volume");
786 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_mkvol_req
));
792 req
.name
[req
.name_len
] = '\0';
793 err
= verify_mkvol_req(ubi
, &req
);
797 mutex_lock(&ubi
->volumes_mutex
);
798 err
= ubi_create_volume(ubi
, &req
);
799 mutex_unlock(&ubi
->volumes_mutex
);
803 err
= put_user(req
.vol_id
, (__user
int32_t *)argp
);
810 /* Remove volume command */
815 dbg_gen("remove volume");
816 err
= get_user(vol_id
, (__user
int32_t *)argp
);
822 desc
= ubi_open_volume(ubi
->ubi_num
, vol_id
, UBI_EXCLUSIVE
);
828 mutex_lock(&ubi
->volumes_mutex
);
829 err
= ubi_remove_volume(desc
, 0);
830 mutex_unlock(&ubi
->volumes_mutex
);
833 * The volume is deleted (unless an error occurred), and the
834 * 'struct ubi_volume' object will be freed when
835 * 'ubi_close_volume()' will call 'put_device()'.
837 ubi_close_volume(desc
);
841 /* Re-size volume command */
846 struct ubi_rsvol_req req
;
848 dbg_gen("re-size volume");
849 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_rsvol_req
));
855 err
= verify_rsvol_req(ubi
, &req
);
859 desc
= ubi_open_volume(ubi
->ubi_num
, req
.vol_id
, UBI_EXCLUSIVE
);
866 pebs
= !!do_div(tmp
, desc
->vol
->usable_leb_size
);
869 mutex_lock(&ubi
->volumes_mutex
);
870 err
= ubi_resize_volume(desc
, pebs
);
871 mutex_unlock(&ubi
->volumes_mutex
);
872 ubi_close_volume(desc
);
876 /* Re-name volumes command */
879 struct ubi_rnvol_req
*req
;
881 dbg_msg("re-name volumes");
882 req
= kmalloc(sizeof(struct ubi_rnvol_req
), GFP_KERNEL
);
888 err
= copy_from_user(req
, argp
, sizeof(struct ubi_rnvol_req
));
895 mutex_lock(&ubi
->mult_mutex
);
896 err
= rename_volumes(ubi
, req
);
897 mutex_unlock(&ubi
->mult_mutex
);
911 static int ctrl_cdev_ioctl(struct inode
*inode
, struct file
*file
,
912 unsigned int cmd
, unsigned long arg
)
915 void __user
*argp
= (void __user
*)arg
;
917 if (!capable(CAP_SYS_RESOURCE
))
921 /* Attach an MTD device command */
924 struct ubi_attach_req req
;
925 struct mtd_info
*mtd
;
927 dbg_gen("attach MTD device");
928 err
= copy_from_user(&req
, argp
, sizeof(struct ubi_attach_req
));
934 if (req
.mtd_num
< 0 ||
935 (req
.ubi_num
< 0 && req
.ubi_num
!= UBI_DEV_NUM_AUTO
)) {
940 mtd
= get_mtd_device(NULL
, req
.mtd_num
);
947 * Note, further request verification is done by
948 * 'ubi_attach_mtd_dev()'.
950 mutex_lock(&ubi_devices_mutex
);
951 err
= ubi_attach_mtd_dev(mtd
, req
.ubi_num
, req
.vid_hdr_offset
);
952 mutex_unlock(&ubi_devices_mutex
);
956 /* @err contains UBI device number */
957 err
= put_user(err
, (__user
int32_t *)argp
);
962 /* Detach an MTD device command */
967 dbg_gen("dettach MTD device");
968 err
= get_user(ubi_num
, (__user
int32_t *)argp
);
974 mutex_lock(&ubi_devices_mutex
);
975 err
= ubi_detach_mtd_dev(ubi_num
, 0);
976 mutex_unlock(&ubi_devices_mutex
);
988 /* UBI control character device operations */
989 struct file_operations ubi_ctrl_cdev_operations
= {
990 .ioctl
= ctrl_cdev_ioctl
,
991 .owner
= THIS_MODULE
,
994 /* UBI character device operations */
995 struct file_operations ubi_cdev_operations
= {
996 .owner
= THIS_MODULE
,
997 .ioctl
= ubi_cdev_ioctl
,
1001 /* UBI volume character device operations */
1002 struct file_operations ubi_vol_cdev_operations
= {
1003 .owner
= THIS_MODULE
,
1004 .open
= vol_cdev_open
,
1005 .release
= vol_cdev_release
,
1006 .llseek
= vol_cdev_llseek
,
1007 .read
= vol_cdev_read
,
1008 .write
= vol_cdev_write
,
1009 .ioctl
= vol_cdev_ioctl
,