| /* |
| * Copyright (c) International Business Machines Corp., 2006 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| * the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| * Author: Artem Bityutskiy (Битюцкий Артём) |
| */ |
| |
| /* This file mostly implements UBI kernel API functions */ |
| |
| #include <linux/module.h> |
| #include <linux/err.h> |
| #include <asm/div64.h> |
| #include "ubi.h" |
| |
| /** |
| * ubi_get_device_info - get information about UBI device. |
| * @ubi_num: UBI device number |
| * @di: the information is stored here |
| * |
| * This function returns %0 in case of success and a %-ENODEV if there is no |
| * such UBI device. |
| */ |
| int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) |
| { |
| const struct ubi_device *ubi; |
| |
| if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || |
| !ubi_devices[ubi_num]) |
| return -ENODEV; |
| |
| ubi = ubi_devices[ubi_num]; |
| di->ubi_num = ubi->ubi_num; |
| di->leb_size = ubi->leb_size; |
| di->min_io_size = ubi->min_io_size; |
| di->ro_mode = ubi->ro_mode; |
| di->cdev = ubi->cdev.dev; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ubi_get_device_info); |
| |
| /** |
| * ubi_get_volume_info - get information about UBI volume. |
| * @desc: volume descriptor |
| * @vi: the information is stored here |
| */ |
| void ubi_get_volume_info(struct ubi_volume_desc *desc, |
| struct ubi_volume_info *vi) |
| { |
| const struct ubi_volume *vol = desc->vol; |
| const struct ubi_device *ubi = vol->ubi; |
| |
| vi->vol_id = vol->vol_id; |
| vi->ubi_num = ubi->ubi_num; |
| vi->size = vol->reserved_pebs; |
| vi->used_bytes = vol->used_bytes; |
| vi->vol_type = vol->vol_type; |
| vi->corrupted = vol->corrupted; |
| vi->upd_marker = vol->upd_marker; |
| vi->alignment = vol->alignment; |
| vi->usable_leb_size = vol->usable_leb_size; |
| vi->name_len = vol->name_len; |
| vi->name = vol->name; |
| vi->cdev = vol->cdev.dev; |
| } |
| EXPORT_SYMBOL_GPL(ubi_get_volume_info); |
| |
| /** |
| * ubi_open_volume - open UBI volume. |
| * @ubi_num: UBI device number |
| * @vol_id: volume ID |
| * @mode: open mode |
| * |
| * The @mode parameter specifies if the volume should be opened in read-only |
| * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that |
| * nobody else will be able to open this volume. UBI allows to have many volume |
| * readers and one writer at a time. |
| * |
| * If a static volume is being opened for the first time since boot, it will be |
| * checked by this function, which means it will be fully read and the CRC |
| * checksum of each logical eraseblock will be checked. |
| * |
| * This function returns volume descriptor in case of success and a negative |
| * error code in case of failure. |
| */ |
| struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) |
| { |
| int err; |
| struct ubi_volume_desc *desc; |
| struct ubi_device *ubi; |
| struct ubi_volume *vol; |
| |
| dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode); |
| |
| if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) |
| return ERR_PTR(-EINVAL); |
| |
| if (mode != UBI_READONLY && mode != UBI_READWRITE && |
| mode != UBI_EXCLUSIVE) |
| return ERR_PTR(-EINVAL); |
| |
| ubi = ubi_devices[ubi_num]; |
| if (!ubi) |
| return ERR_PTR(-ENODEV); |
| |
| if (vol_id < 0 || vol_id >= ubi->vtbl_slots) |
| return ERR_PTR(-EINVAL); |
| |
| desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); |
| if (!desc) |
| return ERR_PTR(-ENOMEM); |
| |
| err = -ENODEV; |
| if (!try_module_get(THIS_MODULE)) |
| goto out_free; |
| |
| spin_lock(&ubi->volumes_lock); |
| vol = ubi->volumes[vol_id]; |
| if (!vol) |
| goto out_unlock; |
| |
| err = -EBUSY; |
| switch (mode) { |
| case UBI_READONLY: |
| if (vol->exclusive) |
| goto out_unlock; |
| vol->readers += 1; |
| break; |
| |
| case UBI_READWRITE: |
| if (vol->exclusive || vol->writers > 0) |
| goto out_unlock; |
| vol->writers += 1; |
| break; |
| |
| case UBI_EXCLUSIVE: |
| if (vol->exclusive || vol->writers || vol->readers) |
| goto out_unlock; |
| vol->exclusive = 1; |
| break; |
| } |
| get_device(&vol->dev); |
| spin_unlock(&ubi->volumes_lock); |
| |
| desc->vol = vol; |
| desc->mode = mode; |
| |
| /* |
| * To prevent simultaneous checks of the same volume we use |
| * @volumes_mutex, although it is not the purpose it was introduced |
| * for. |
| */ |
| mutex_lock(&ubi->volumes_mutex); |
| if (!vol->checked) { |
| /* This is the first open - check the volume */ |
| err = ubi_check_volume(ubi, vol_id); |
| if (err < 0) { |
| mutex_unlock(&ubi->volumes_mutex); |
| ubi_close_volume(desc); |
| return ERR_PTR(err); |
| } |
| if (err == 1) { |
| ubi_warn("volume %d on UBI device %d is corrupted", |
| vol_id, ubi->ubi_num); |
| vol->corrupted = 1; |
| } |
| vol->checked = 1; |
| } |
| mutex_unlock(&ubi->volumes_mutex); |
| |
| return desc; |
| |
| out_unlock: |
| spin_unlock(&ubi->volumes_lock); |
| module_put(THIS_MODULE); |
| out_free: |
| kfree(desc); |
| return ERR_PTR(err); |
| } |
| EXPORT_SYMBOL_GPL(ubi_open_volume); |
| |
| /** |
| * ubi_open_volume_nm - open UBI volume by name. |
| * @ubi_num: UBI device number |
| * @name: volume name |
| * @mode: open mode |
| * |
| * This function is similar to 'ubi_open_volume()', but opens a volume by name. |
| */ |
| struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, |
| int mode) |
| { |
| int i, vol_id = -1, len; |
| struct ubi_device *ubi; |
| |
| dbg_msg("open volume %s, mode %d", name, mode); |
| |
| if (!name) |
| return ERR_PTR(-EINVAL); |
| |
| len = strnlen(name, UBI_VOL_NAME_MAX + 1); |
| if (len > UBI_VOL_NAME_MAX) |
| return ERR_PTR(-EINVAL); |
| |
| if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) |
| return ERR_PTR(-EINVAL); |
| |
| ubi = ubi_devices[ubi_num]; |
| if (!ubi) |
| return ERR_PTR(-ENODEV); |
| |
| spin_lock(&ubi->volumes_lock); |
| /* Walk all volumes of this UBI device */ |
| for (i = 0; i < ubi->vtbl_slots; i++) { |
| struct ubi_volume *vol = ubi->volumes[i]; |
| |
| if (vol && len == vol->name_len && !strcmp(name, vol->name)) { |
| vol_id = i; |
| break; |
| } |
| } |
| spin_unlock(&ubi->volumes_lock); |
| |
| if (vol_id < 0) |
| return ERR_PTR(-ENODEV); |
| |
| return ubi_open_volume(ubi_num, vol_id, mode); |
| } |
| EXPORT_SYMBOL_GPL(ubi_open_volume_nm); |
| |
| /** |
| * ubi_close_volume - close UBI volume. |
| * @desc: volume descriptor |
| */ |
| void ubi_close_volume(struct ubi_volume_desc *desc) |
| { |
| struct ubi_volume *vol = desc->vol; |
| |
| dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode); |
| |
| spin_lock(&vol->ubi->volumes_lock); |
| switch (desc->mode) { |
| case UBI_READONLY: |
| vol->readers -= 1; |
| break; |
| case UBI_READWRITE: |
| vol->writers -= 1; |
| break; |
| case UBI_EXCLUSIVE: |
| vol->exclusive = 0; |
| } |
| spin_unlock(&vol->ubi->volumes_lock); |
| |
| kfree(desc); |
| put_device(&vol->dev); |
| module_put(THIS_MODULE); |
| } |
| EXPORT_SYMBOL_GPL(ubi_close_volume); |
| |
| /** |
| * ubi_leb_read - read data. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number to read from |
| * @buf: buffer where to store the read data |
| * @offset: offset within the logical eraseblock to read from |
| * @len: how many bytes to read |
| * @check: whether UBI has to check the read data's CRC or not. |
| * |
| * This function reads data from offset @offset of logical eraseblock @lnum and |
| * stores the data at @buf. When reading from static volumes, @check specifies |
| * whether the data has to be checked or not. If yes, the whole logical |
| * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC |
| * checksum is per-eraseblock). So checking may substantially slow down the |
| * read speed. The @check argument is ignored for dynamic volumes. |
| * |
| * In case of success, this function returns zero. In case of failure, this |
| * function returns a negative error code. |
| * |
| * %-EBADMSG error code is returned: |
| * o for both static and dynamic volumes if MTD driver has detected a data |
| * integrity problem (unrecoverable ECC checksum mismatch in case of NAND); |
| * o for static volumes in case of data CRC mismatch. |
| * |
| * If the volume is damaged because of an interrupted update this function just |
| * returns immediately with %-EBADF error code. |
| */ |
| int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, |
| int len, int check) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int err, vol_id = vol->vol_id; |
| |
| dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); |
| |
| if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 || |
| lnum >= vol->used_ebs || offset < 0 || len < 0 || |
| offset + len > vol->usable_leb_size) |
| return -EINVAL; |
| |
| if (vol->vol_type == UBI_STATIC_VOLUME) { |
| if (vol->used_ebs == 0) |
| /* Empty static UBI volume */ |
| return 0; |
| if (lnum == vol->used_ebs - 1 && |
| offset + len > vol->last_eb_bytes) |
| return -EINVAL; |
| } |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| if (len == 0) |
| return 0; |
| |
| err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check); |
| if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) { |
| ubi_warn("mark volume %d as corrupted", vol_id); |
| vol->corrupted = 1; |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_read); |
| |
| /** |
| * ubi_leb_write - write data. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number to write to |
| * @buf: data to write |
| * @offset: offset within the logical eraseblock where to write |
| * @len: how many bytes to write |
| * @dtype: expected data type |
| * |
| * This function writes @len bytes of data from @buf to offset @offset of |
| * logical eraseblock @lnum. The @dtype argument describes expected lifetime of |
| * the data. |
| * |
| * This function takes care of physical eraseblock write failures. If write to |
| * the physical eraseblock write operation fails, the logical eraseblock is |
| * re-mapped to another physical eraseblock, the data is recovered, and the |
| * write finishes. UBI has a pool of reserved physical eraseblocks for this. |
| * |
| * If all the data were successfully written, zero is returned. If an error |
| * occurred and UBI has not been able to recover from it, this function returns |
| * a negative error code. Note, in case of an error, it is possible that |
| * something was still written to the flash media, but that may be some |
| * garbage. |
| * |
| * If the volume is damaged because of an interrupted update this function just |
| * returns immediately with %-EBADF code. |
| */ |
| int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, |
| int offset, int len, int dtype) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int vol_id = vol->vol_id; |
| |
| dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset); |
| |
| if (vol_id < 0 || vol_id >= ubi->vtbl_slots) |
| return -EINVAL; |
| |
| if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) |
| return -EROFS; |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || |
| offset + len > vol->usable_leb_size || offset % ubi->min_io_size || |
| len % ubi->min_io_size) |
| return -EINVAL; |
| |
| if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && |
| dtype != UBI_UNKNOWN) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| if (len == 0) |
| return 0; |
| |
| return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype); |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_write); |
| |
| /* |
| * ubi_leb_change - change logical eraseblock atomically. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number to change |
| * @buf: data to write |
| * @len: how many bytes to write |
| * @dtype: expected data type |
| * |
| * This function changes the contents of a logical eraseblock atomically. @buf |
| * has to contain new logical eraseblock data, and @len - the length of the |
| * data, which has to be aligned. The length may be shorter then the logical |
| * eraseblock size, ant the logical eraseblock may be appended to more times |
| * later on. This function guarantees that in case of an unclean reboot the old |
| * contents is preserved. Returns zero in case of success and a negative error |
| * code in case of failure. |
| */ |
| int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, |
| int len, int dtype) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int vol_id = vol->vol_id; |
| |
| dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum); |
| |
| if (vol_id < 0 || vol_id >= ubi->vtbl_slots) |
| return -EINVAL; |
| |
| if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) |
| return -EROFS; |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || |
| len > vol->usable_leb_size || len % ubi->min_io_size) |
| return -EINVAL; |
| |
| if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && |
| dtype != UBI_UNKNOWN) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| if (len == 0) |
| return 0; |
| |
| return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype); |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_change); |
| |
| /** |
| * ubi_leb_erase - erase logical eraseblock. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number |
| * |
| * This function un-maps logical eraseblock @lnum and synchronously erases the |
| * correspondent physical eraseblock. Returns zero in case of success and a |
| * negative error code in case of failure. |
| * |
| * If the volume is damaged because of an interrupted update this function just |
| * returns immediately with %-EBADF code. |
| */ |
| int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int err, vol_id = vol->vol_id; |
| |
| dbg_msg("erase LEB %d:%d", vol_id, lnum); |
| |
| if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) |
| return -EROFS; |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| err = ubi_eba_unmap_leb(ubi, vol, lnum); |
| if (err) |
| return err; |
| |
| return ubi_wl_flush(ubi); |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_erase); |
| |
| /** |
| * ubi_leb_unmap - un-map logical eraseblock. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number |
| * |
| * This function un-maps logical eraseblock @lnum and schedules the |
| * corresponding physical eraseblock for erasure, so that it will eventually be |
| * physically erased in background. This operation is much faster then the |
| * erase operation. |
| * |
| * Unlike erase, the un-map operation does not guarantee that the logical |
| * eraseblock will contain all 0xFF bytes when UBI is initialized again. For |
| * example, if several logical eraseblocks are un-mapped, and an unclean reboot |
| * happens after this, the logical eraseblocks will not necessarily be |
| * un-mapped again when this MTD device is attached. They may actually be |
| * mapped to the same physical eraseblocks again. So, this function has to be |
| * used with care. |
| * |
| * In other words, when un-mapping a logical eraseblock, UBI does not store |
| * any information about this on the flash media, it just marks the logical |
| * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical |
| * eraseblock is physically erased, it will be mapped again to the same logical |
| * eraseblock when the MTD device is attached again. |
| * |
| * The main and obvious use-case of this function is when the contents of a |
| * logical eraseblock has to be re-written. Then it is much more efficient to |
| * first un-map it, then write new data, rather then first erase it, then write |
| * new data. Note, once new data has been written to the logical eraseblock, |
| * UBI guarantees that the old contents has gone forever. In other words, if an |
| * unclean reboot happens after the logical eraseblock has been un-mapped and |
| * then written to, it will contain the last written data. |
| * |
| * This function returns zero in case of success and a negative error code in |
| * case of failure. If the volume is damaged because of an interrupted update |
| * this function just returns immediately with %-EBADF code. |
| */ |
| int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int vol_id = vol->vol_id; |
| |
| dbg_msg("unmap LEB %d:%d", vol_id, lnum); |
| |
| if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) |
| return -EROFS; |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| return ubi_eba_unmap_leb(ubi, vol, lnum); |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_unmap); |
| |
| /** |
| * ubi_leb_map - map logical erasblock to a physical eraseblock. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number |
| * @dtype: expected data type |
| * |
| * This function maps an un-mapped logical eraseblock @lnum to a physical |
| * eraseblock. This means, that after a successfull invocation of this |
| * function the logical eraseblock @lnum will be empty (contain only %0xFF |
| * bytes) and be mapped to a physical eraseblock, even if an unclean reboot |
| * happens. |
| * |
| * This function returns zero in case of success, %-EBADF if the volume is |
| * damaged because of an interrupted update, %-EBADMSG if the logical |
| * eraseblock is already mapped, and other negative error codes in case of |
| * other failures. |
| */ |
| int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype) |
| { |
| struct ubi_volume *vol = desc->vol; |
| struct ubi_device *ubi = vol->ubi; |
| int vol_id = vol->vol_id; |
| |
| dbg_msg("unmap LEB %d:%d", vol_id, lnum); |
| |
| if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) |
| return -EROFS; |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs) |
| return -EINVAL; |
| |
| if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && |
| dtype != UBI_UNKNOWN) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| if (vol->eba_tbl[lnum] >= 0) |
| return -EBADMSG; |
| |
| return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype); |
| } |
| EXPORT_SYMBOL_GPL(ubi_leb_map); |
| |
| /** |
| * ubi_is_mapped - check if logical eraseblock is mapped. |
| * @desc: volume descriptor |
| * @lnum: logical eraseblock number |
| * |
| * This function checks if logical eraseblock @lnum is mapped to a physical |
| * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily |
| * mean it will still be un-mapped after the UBI device is re-attached. The |
| * logical eraseblock may become mapped to the physical eraseblock it was last |
| * mapped to. |
| * |
| * This function returns %1 if the LEB is mapped, %0 if not, and a negative |
| * error code in case of failure. If the volume is damaged because of an |
| * interrupted update this function just returns immediately with %-EBADF error |
| * code. |
| */ |
| int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum) |
| { |
| struct ubi_volume *vol = desc->vol; |
| |
| dbg_msg("test LEB %d:%d", vol->vol_id, lnum); |
| |
| if (lnum < 0 || lnum >= vol->reserved_pebs) |
| return -EINVAL; |
| |
| if (vol->upd_marker) |
| return -EBADF; |
| |
| return vol->eba_tbl[lnum] >= 0; |
| } |
| EXPORT_SYMBOL_GPL(ubi_is_mapped); |