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
33 #include <linux/module.h>
34 #include <linux/stat.h>
35 #include <linux/ioctl.h>
36 #include <linux/capability.h>
37 #include <mtd/ubi-user.h>
38 #include <asm/uaccess.h>
39 #include <asm/div64.h>
43 * Maximum sequence numbers of UBI and volume character device IOCTLs (direct
44 * logical eraseblock erase is a debug-only feature).
46 #define UBI_CDEV_IOC_MAX_SEQ 2
47 #ifndef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
48 #define VOL_CDEV_IOC_MAX_SEQ 1
50 #define VOL_CDEV_IOC_MAX_SEQ 2
54 * major_to_device - get UBI device object by character device major number.
55 * @major: major number
57 * This function returns a pointer to the UBI device object.
59 static struct ubi_device *major_to_device(int major)
63 for (i = 0; i < ubi_devices_cnt; i++)
64 if (ubi_devices[i] && ubi_devices[i]->major == major)
65 return ubi_devices[i];
70 * get_exclusive - get exclusive access to an UBI volume.
71 * @desc: volume descriptor
73 * This function changes UBI volume open mode to "exclusive". Returns previous
74 * mode value (positive integer) in case of success and a negative error code
77 static int get_exclusive(struct ubi_volume_desc *desc)
80 struct ubi_volume *vol = desc->vol;
82 spin_lock(&vol->ubi->volumes_lock);
83 users = vol->readers + vol->writers + vol->exclusive;
84 ubi_assert(users > 0);
86 dbg_err("%d users for volume %d", users, vol->vol_id);
89 vol->readers = vol->writers = 0;
92 desc->mode = UBI_EXCLUSIVE;
94 spin_unlock(&vol->ubi->volumes_lock);
100 * revoke_exclusive - revoke exclusive mode.
101 * @desc: volume descriptor
102 * @mode: new mode to switch to
104 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
106 struct ubi_volume *vol = desc->vol;
108 spin_lock(&vol->ubi->volumes_lock);
109 ubi_assert(vol->readers == 0 && vol->writers == 0);
110 ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
112 if (mode == UBI_READONLY)
114 else if (mode == UBI_READWRITE)
118 spin_unlock(&vol->ubi->volumes_lock);
123 static int vol_cdev_open(struct inode *inode, struct file *file)
125 struct ubi_volume_desc *desc;
126 const struct ubi_device *ubi = major_to_device(imajor(inode));
127 int vol_id = iminor(inode) - 1;
130 if (file->f_mode & FMODE_WRITE)
131 mode = UBI_READWRITE;
135 dbg_msg("open volume %d, mode %d", vol_id, mode);
137 desc = ubi_open_volume(ubi->ubi_num, vol_id, mode);
139 return PTR_ERR(desc);
141 file->private_data = desc;
145 static int vol_cdev_release(struct inode *inode, struct file *file)
147 struct ubi_volume_desc *desc = file->private_data;
148 struct ubi_volume *vol = desc->vol;
150 dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode);
153 ubi_warn("update of volume %d not finished, volume is damaged",
159 ubi_close_volume(desc);
163 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
165 struct ubi_volume_desc *desc = file->private_data;
166 struct ubi_volume *vol = desc->vol;
170 /* Update is in progress, seeking is prohibited */
176 case 0: /* SEEK_SET */
179 case 1: /* SEEK_CUR */
180 new_offset = file->f_pos + offset;
182 case 2: /* SEEK_END */
183 new_offset = vol->used_bytes + offset;
189 if (new_offset < 0 || new_offset > vol->used_bytes) {
190 dbg_err("bad seek %lld", new_offset);
194 dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
195 vol->vol_id, offset, origin, new_offset);
197 file->f_pos = new_offset;
201 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
204 struct ubi_volume_desc *desc = file->private_data;
205 struct ubi_volume *vol = desc->vol;
206 struct ubi_device *ubi = vol->ubi;
207 int err, lnum, off, len, vol_id = desc->vol->vol_id, tbuf_size;
208 size_t count_save = count;
212 dbg_msg("read %zd bytes from offset %lld of volume %d",
213 count, *offp, vol_id);
219 if (vol->upd_marker) {
220 dbg_err("damaged volume, update marker is set");
223 if (*offp == vol->used_bytes || count == 0)
227 dbg_msg("read from corrupted volume %d", vol_id);
229 if (*offp + count > vol->used_bytes)
230 count_save = count = vol->used_bytes - *offp;
232 tbuf_size = vol->usable_leb_size;
233 if (count < tbuf_size)
234 tbuf_size = ALIGN(count, ubi->min_io_size);
235 tbuf = vmalloc(tbuf_size);
239 len = count > tbuf_size ? tbuf_size : count;
242 off = do_div(tmp, vol->usable_leb_size);
248 if (off + len >= vol->usable_leb_size)
249 len = vol->usable_leb_size - off;
251 err = ubi_eba_read_leb(ubi, vol_id, lnum, tbuf, off, len, 0);
256 if (off == vol->usable_leb_size) {
258 off -= vol->usable_leb_size;
264 err = copy_to_user(buf, tbuf, len);
271 len = count > tbuf_size ? tbuf_size : count;
275 return err ? err : count_save - count;
278 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
281 * This function allows to directly write to dynamic UBI volumes, without
282 * issuing the volume update operation. Available only as a debugging feature.
283 * Very useful for testing UBI.
285 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
286 size_t count, loff_t *offp)
288 struct ubi_volume_desc *desc = file->private_data;
289 struct ubi_volume *vol = desc->vol;
290 struct ubi_device *ubi = vol->ubi;
291 int lnum, off, len, tbuf_size, vol_id = vol->vol_id, err = 0;
292 size_t count_save = count;
296 dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
297 count, *offp, desc->vol->vol_id);
299 if (vol->vol_type == UBI_STATIC_VOLUME)
303 off = do_div(tmp, vol->usable_leb_size);
306 if (off % ubi->min_io_size) {
307 dbg_err("unaligned position");
311 if (*offp + count > vol->used_bytes)
312 count_save = count = vol->used_bytes - *offp;
314 /* We can write only in fractions of the minimum I/O unit */
315 if (count % ubi->min_io_size) {
316 dbg_err("unaligned write length");
320 tbuf_size = vol->usable_leb_size;
321 if (count < tbuf_size)
322 tbuf_size = ALIGN(count, ubi->min_io_size);
323 tbuf = vmalloc(tbuf_size);
327 len = count > tbuf_size ? tbuf_size : count;
332 if (off + len >= vol->usable_leb_size)
333 len = vol->usable_leb_size - off;
335 err = copy_from_user(tbuf, buf, len);
341 err = ubi_eba_write_leb(ubi, vol_id, lnum, tbuf, off, len,
347 if (off == vol->usable_leb_size) {
349 off -= vol->usable_leb_size;
355 len = count > tbuf_size ? tbuf_size : count;
359 return err ? err : count_save - count;
363 #define vol_cdev_direct_write(file, buf, count, offp) -EPERM
364 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
366 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
367 size_t count, loff_t *offp)
370 struct ubi_volume_desc *desc = file->private_data;
371 struct ubi_volume *vol = desc->vol;
372 struct ubi_device *ubi = vol->ubi;
375 return vol_cdev_direct_write(file, buf, count, offp);
377 err = ubi_more_update_data(ubi, vol->vol_id, buf, count);
379 ubi_err("cannot write %zd bytes of update data", count);
385 * Update is finished, @err contains number of actually written
390 err = ubi_check_volume(ubi, vol->vol_id);
395 ubi_warn("volume %d on UBI device %d is corrupted",
396 vol->vol_id, ubi->ubi_num);
400 ubi_gluebi_updated(vol);
401 revoke_exclusive(desc, UBI_READWRITE);
408 static int vol_cdev_ioctl(struct inode *inode, struct file *file,
409 unsigned int cmd, unsigned long arg)
412 struct ubi_volume_desc *desc = file->private_data;
413 struct ubi_volume *vol = desc->vol;
414 struct ubi_device *ubi = vol->ubi;
415 void __user *argp = (void __user *)arg;
417 if (_IOC_NR(cmd) > VOL_CDEV_IOC_MAX_SEQ ||
418 _IOC_TYPE(cmd) != UBI_VOL_IOC_MAGIC)
421 if (_IOC_DIR(cmd) && _IOC_READ)
422 err = !access_ok(VERIFY_WRITE, argp, _IOC_SIZE(cmd));
423 else if (_IOC_DIR(cmd) && _IOC_WRITE)
424 err = !access_ok(VERIFY_READ, argp, _IOC_SIZE(cmd));
430 /* Volume update command */
433 int64_t bytes, rsvd_bytes;
435 if (!capable(CAP_SYS_RESOURCE)) {
440 err = copy_from_user(&bytes, argp, sizeof(int64_t));
446 if (desc->mode == UBI_READONLY) {
451 rsvd_bytes = vol->reserved_pebs * (ubi->leb_size-vol->data_pad);
452 if (bytes < 0 || bytes > rsvd_bytes) {
457 err = get_exclusive(desc);
461 err = ubi_start_update(ubi, vol->vol_id, bytes);
463 revoke_exclusive(desc, UBI_READWRITE);
469 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
470 /* Logical eraseblock erasure command */
475 err = __get_user(lnum, (__user int32_t *)argp);
481 if (desc->mode == UBI_READONLY) {
486 if (lnum < 0 || lnum >= vol->reserved_pebs) {
491 if (vol->vol_type != UBI_DYNAMIC_VOLUME) {
496 dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
497 err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum);
501 err = ubi_wl_flush(ubi);
515 * verify_mkvol_req - verify volume creation request.
516 * @ubi: UBI device description object
517 * @req: the request to check
519 * This function zero if the request is correct, and %-EINVAL if not.
521 static int verify_mkvol_req(const struct ubi_device *ubi,
522 const struct ubi_mkvol_req *req)
524 int n, err = -EINVAL;
526 if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
530 if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
531 req->vol_id != UBI_VOL_NUM_AUTO)
534 if (req->alignment == 0)
540 if (req->vol_type != UBI_DYNAMIC_VOLUME &&
541 req->vol_type != UBI_STATIC_VOLUME)
544 if (req->alignment > ubi->leb_size)
547 n = req->alignment % ubi->min_io_size;
548 if (req->alignment != 1 && n)
551 if (req->name_len > UBI_VOL_NAME_MAX) {
559 dbg_err("bad volume creation request");
560 ubi_dbg_dump_mkvol_req(req);
565 * verify_rsvol_req - verify volume re-size request.
566 * @ubi: UBI device description object
567 * @req: the request to check
569 * This function returns zero if the request is correct, and %-EINVAL if not.
571 static int verify_rsvol_req(const struct ubi_device *ubi,
572 const struct ubi_rsvol_req *req)
577 if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
583 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
584 unsigned int cmd, unsigned long arg)
587 struct ubi_device *ubi;
588 struct ubi_volume_desc *desc;
589 void __user *argp = (void __user *)arg;
591 if (_IOC_NR(cmd) > UBI_CDEV_IOC_MAX_SEQ ||
592 _IOC_TYPE(cmd) != UBI_IOC_MAGIC)
595 if (_IOC_DIR(cmd) && _IOC_READ)
596 err = !access_ok(VERIFY_WRITE, argp, _IOC_SIZE(cmd));
597 else if (_IOC_DIR(cmd) && _IOC_WRITE)
598 err = !access_ok(VERIFY_READ, argp, _IOC_SIZE(cmd));
602 if (!capable(CAP_SYS_RESOURCE))
605 ubi = major_to_device(imajor(inode));
610 /* Create volume command */
613 struct ubi_mkvol_req req;
615 dbg_msg("create volume");
616 err = __copy_from_user(&req, argp,
617 sizeof(struct ubi_mkvol_req));
623 err = verify_mkvol_req(ubi, &req);
627 req.name[req.name_len] = '\0';
629 err = ubi_create_volume(ubi, &req);
633 err = __put_user(req.vol_id, (__user int32_t *)argp);
640 /* Remove volume command */
645 dbg_msg("remove volume");
646 err = __get_user(vol_id, (__user int32_t *)argp);
652 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
658 err = ubi_remove_volume(desc);
660 ubi_close_volume(desc);
665 /* Re-size volume command */
670 struct ubi_rsvol_req req;
672 dbg_msg("re-size volume");
673 err = __copy_from_user(&req, argp,
674 sizeof(struct ubi_rsvol_req));
680 err = verify_rsvol_req(ubi, &req);
684 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
691 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
694 err = ubi_resize_volume(desc, pebs);
695 ubi_close_volume(desc);
707 /* UBI character device operations */
708 struct file_operations ubi_cdev_operations = {
709 .owner = THIS_MODULE,
710 .ioctl = ubi_cdev_ioctl,
714 /* UBI volume character device operations */
715 struct file_operations ubi_vol_cdev_operations = {
716 .owner = THIS_MODULE,
717 .open = vol_cdev_open,
718 .release = vol_cdev_release,
719 .llseek = vol_cdev_llseek,
720 .read = vol_cdev_read,
721 .write = vol_cdev_write,
722 .ioctl = vol_cdev_ioctl,