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 - 1)) {
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 - 1)) {
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 = (long long)vol->reserved_pebs *
441 ubi->leb_size-vol->data_pad;
442 if (bytes < 0 || bytes > rsvd_bytes) {
447 err = get_exclusive(desc);
451 err = ubi_start_update(ubi, vol, bytes);
453 revoke_exclusive(desc, UBI_READWRITE);
457 /* Atomic logical eraseblock change command */
460 struct ubi_leb_change_req req;
462 err = copy_from_user(&req, argp,
463 sizeof(struct ubi_leb_change_req));
469 if (desc->mode == UBI_READONLY ||
470 vol->vol_type == UBI_STATIC_VOLUME) {
475 /* Validate the request */
477 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
478 req.bytes < 0 || req.lnum >= vol->usable_leb_size)
480 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
481 req.dtype != UBI_UNKNOWN)
484 err = get_exclusive(desc);
488 err = ubi_start_leb_change(ubi, vol, &req);
490 revoke_exclusive(desc, UBI_READWRITE);
494 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
495 /* Logical eraseblock erasure command */
500 err = get_user(lnum, (__user int32_t *)argp);
506 if (desc->mode == UBI_READONLY ||
507 vol->vol_type == UBI_STATIC_VOLUME) {
512 if (lnum < 0 || lnum >= vol->reserved_pebs) {
517 dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
518 err = ubi_eba_unmap_leb(ubi, vol, lnum);
522 err = ubi_wl_flush(ubi);
536 * verify_mkvol_req - verify volume creation request.
537 * @ubi: UBI device description object
538 * @req: the request to check
540 * This function zero if the request is correct, and %-EINVAL if not.
542 static int verify_mkvol_req(const struct ubi_device *ubi,
543 const struct ubi_mkvol_req *req)
545 int n, err = -EINVAL;
547 if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
551 if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
552 req->vol_id != UBI_VOL_NUM_AUTO)
555 if (req->alignment == 0)
561 if (req->vol_type != UBI_DYNAMIC_VOLUME &&
562 req->vol_type != UBI_STATIC_VOLUME)
565 if (req->alignment > ubi->leb_size)
568 n = req->alignment & (ubi->min_io_size - 1);
569 if (req->alignment != 1 && n)
572 if (req->name_len > UBI_VOL_NAME_MAX) {
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)
604 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
605 unsigned int cmd, unsigned long arg)
608 struct ubi_device *ubi;
609 struct ubi_volume_desc *desc;
610 void __user *argp = (void __user *)arg;
612 if (!capable(CAP_SYS_RESOURCE))
615 ubi = ubi_get_by_major(imajor(inode));
620 /* Create volume command */
623 struct ubi_mkvol_req req;
625 dbg_msg("create volume");
626 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
632 err = verify_mkvol_req(ubi, &req);
636 req.name[req.name_len] = '\0';
638 mutex_lock(&ubi->volumes_mutex);
639 err = ubi_create_volume(ubi, &req);
640 mutex_unlock(&ubi->volumes_mutex);
644 err = put_user(req.vol_id, (__user int32_t *)argp);
651 /* Remove volume command */
656 dbg_msg("remove volume");
657 err = get_user(vol_id, (__user int32_t *)argp);
663 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
669 mutex_lock(&ubi->volumes_mutex);
670 err = ubi_remove_volume(desc);
671 mutex_unlock(&ubi->volumes_mutex);
674 * The volume is deleted (unless an error occurred), and the
675 * 'struct ubi_volume' object will be freed when
676 * 'ubi_close_volume()' will call 'put_device()'.
678 ubi_close_volume(desc);
682 /* Re-size volume command */
687 struct ubi_rsvol_req req;
689 dbg_msg("re-size volume");
690 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
696 err = verify_rsvol_req(ubi, &req);
700 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
707 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
710 mutex_lock(&ubi->volumes_mutex);
711 err = ubi_resize_volume(desc, pebs);
712 mutex_unlock(&ubi->volumes_mutex);
713 ubi_close_volume(desc);
726 static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
727 unsigned int cmd, unsigned long arg)
730 void __user *argp = (void __user *)arg;
732 if (!capable(CAP_SYS_RESOURCE))
736 /* Attach an MTD device command */
739 struct ubi_attach_req req;
740 struct mtd_info *mtd;
742 dbg_msg("attach MTD device");
743 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
749 if (req.mtd_num < 0 ||
750 (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
755 mtd = get_mtd_device(NULL, req.mtd_num);
762 * Note, further request verification is done by
763 * 'ubi_attach_mtd_dev()'.
765 mutex_lock(&ubi_devices_mutex);
766 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
767 mutex_unlock(&ubi_devices_mutex);
771 /* @err contains UBI device number */
772 err = put_user(err, (__user int32_t *)argp);
777 /* Detach an MTD device command */
782 dbg_msg("dettach MTD device");
783 err = get_user(ubi_num, (__user int32_t *)argp);
789 mutex_lock(&ubi_devices_mutex);
790 err = ubi_detach_mtd_dev(ubi_num, 0);
791 mutex_unlock(&ubi_devices_mutex);
803 /* UBI control character device operations */
804 struct file_operations ubi_ctrl_cdev_operations = {
805 .ioctl = ctrl_cdev_ioctl,
806 .owner = THIS_MODULE,
809 /* UBI character device operations */
810 struct file_operations ubi_cdev_operations = {
811 .owner = THIS_MODULE,
812 .ioctl = ubi_cdev_ioctl,
816 /* UBI volume character device operations */
817 struct file_operations ubi_vol_cdev_operations = {
818 .owner = THIS_MODULE,
819 .open = vol_cdev_open,
820 .release = vol_cdev_release,
821 .llseek = vol_cdev_llseek,
822 .read = vol_cdev_read,
823 .write = vol_cdev_write,
824 .ioctl = vol_cdev_ioctl,