diff options
Diffstat (limited to 'drivers/mtd/ubi/kapi.c')
| -rw-r--r-- | drivers/mtd/ubi/kapi.c | 867 |
1 files changed, 867 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c new file mode 100644 index 000000000..0b8f0c462 --- /dev/null +++ b/drivers/mtd/ubi/kapi.c @@ -0,0 +1,867 @@ +/* + * 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 <linux/slab.h> +#include <linux/namei.h> +#include <linux/fs.h> +#include <asm/div64.h> +#include "ubi.h" + +/** + * ubi_do_get_device_info - get information about UBI device. + * @ubi: UBI device description object + * @di: the information is stored here + * + * This function is the same as 'ubi_get_device_info()', but it assumes the UBI + * device is locked and cannot disappear. + */ +void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di) +{ + di->ubi_num = ubi->ubi_num; + di->leb_size = ubi->leb_size; + di->leb_start = ubi->leb_start; + di->min_io_size = ubi->min_io_size; + di->max_write_size = ubi->max_write_size; + di->ro_mode = ubi->ro_mode; + di->cdev = ubi->cdev.dev; +} +EXPORT_SYMBOL_GPL(ubi_do_get_device_info); + +/** + * 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, %-EINVAL if the UBI device + * number is invalid, and %-ENODEV if there is no such UBI device. + */ +int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) +{ + struct ubi_device *ubi; + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) + return -EINVAL; + ubi = ubi_get_device(ubi_num); + if (!ubi) + return -ENODEV; + ubi_do_get_device_info(ubi, di); + ubi_put_device(ubi); + return 0; +} +EXPORT_SYMBOL_GPL(ubi_get_device_info); + +/** + * ubi_do_get_volume_info - get information about UBI volume. + * @ubi: UBI device description object + * @vol: volume description object + * @vi: the information is stored here + */ +void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol, + struct ubi_volume_info *vi) +{ + 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; +} + +/** + * 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) +{ + ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi); +} +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_gen("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 && mode != UBI_METAONLY) + return ERR_PTR(-EINVAL); + + /* + * First of all, we have to get the UBI device to prevent its removal. + */ + ubi = ubi_get_device(ubi_num); + if (!ubi) + return ERR_PTR(-ENODEV); + + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) { + err = -EINVAL; + goto out_put_ubi; + } + + desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); + if (!desc) { + err = -ENOMEM; + goto out_put_ubi; + } + + 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 || + vol->metaonly) + goto out_unlock; + vol->exclusive = 1; + break; + + case UBI_METAONLY: + if (vol->metaonly || vol->exclusive) + goto out_unlock; + vol->metaonly = 1; + break; + } + get_device(&vol->dev); + vol->ref_count += 1; + spin_unlock(&ubi->volumes_lock); + + desc->vol = vol; + desc->mode = mode; + + mutex_lock(&ubi->ckvol_mutex); + if (!vol->checked && !vol->skip_check) { + /* This is the first open - check the volume */ + err = ubi_check_volume(ubi, vol_id); + if (err < 0) { + mutex_unlock(&ubi->ckvol_mutex); + ubi_close_volume(desc); + return ERR_PTR(err); + } + if (err == 1) { + ubi_warn(ubi, "volume %d on UBI device %d is corrupted", + vol_id, ubi->ubi_num); + vol->corrupted = 1; + } + vol->checked = 1; + } + mutex_unlock(&ubi->ckvol_mutex); + + return desc; + +out_unlock: + spin_unlock(&ubi->volumes_lock); + module_put(THIS_MODULE); +out_free: + kfree(desc); +out_put_ubi: + ubi_err(ubi, "cannot open device %d, volume %d, error %d", + ubi_num, vol_id, err); + ubi_put_device(ubi); + 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; + struct ubi_volume_desc *ret; + + dbg_gen("open device %d, volume %s, mode %d", ubi_num, 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_get_device(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) + ret = ubi_open_volume(ubi_num, vol_id, mode); + else + ret = ERR_PTR(-ENODEV); + + /* + * We should put the UBI device even in case of success, because + * 'ubi_open_volume()' took a reference as well. + */ + ubi_put_device(ubi); + return ret; +} +EXPORT_SYMBOL_GPL(ubi_open_volume_nm); + +/** + * ubi_open_volume_path - open UBI volume by its character device node path. + * @pathname: volume character device node path + * @mode: open mode + * + * This function is similar to 'ubi_open_volume()', but opens a volume the path + * to its character device node. + */ +struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode) +{ + int error, ubi_num, vol_id; + struct path path; + struct kstat stat; + + dbg_gen("open volume %s, mode %d", pathname, mode); + + if (!pathname || !*pathname) + return ERR_PTR(-EINVAL); + + error = kern_path(pathname, LOOKUP_FOLLOW, &path); + if (error) + return ERR_PTR(error); + + error = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT); + path_put(&path); + if (error) + return ERR_PTR(error); + + if (!S_ISCHR(stat.mode)) + return ERR_PTR(-EINVAL); + + ubi_num = ubi_major2num(MAJOR(stat.rdev)); + vol_id = MINOR(stat.rdev) - 1; + + if (vol_id >= 0 && ubi_num >= 0) + return ubi_open_volume(ubi_num, vol_id, mode); + return ERR_PTR(-ENODEV); +} +EXPORT_SYMBOL_GPL(ubi_open_volume_path); + +/** + * ubi_close_volume - close UBI volume. + * @desc: volume descriptor + */ +void ubi_close_volume(struct ubi_volume_desc *desc) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + + dbg_gen("close device %d, volume %d, mode %d", + ubi->ubi_num, vol->vol_id, desc->mode); + + spin_lock(&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; + break; + case UBI_METAONLY: + vol->metaonly = 0; + break; + } + vol->ref_count -= 1; + spin_unlock(&ubi->volumes_lock); + + kfree(desc); + put_device(&vol->dev); + ubi_put_device(ubi); + module_put(THIS_MODULE); +} +EXPORT_SYMBOL_GPL(ubi_close_volume); + +/** + * leb_read_sanity_check - does sanity checks on read requests. + * @desc: volume descriptor + * @lnum: logical eraseblock number to read from + * @offset: offset within the logical eraseblock to read from + * @len: how many bytes to read + * + * This function is used by ubi_leb_read() and ubi_leb_read_sg() + * to perform sanity checks. + */ +static int leb_read_sanity_check(struct ubi_volume_desc *desc, int lnum, + int offset, int len) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + 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; + + return 0; +} + +/** + * 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_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); + + err = leb_read_sanity_check(desc, lnum, offset, len); + if (err < 0) + return err; + + if (len == 0) + return 0; + + err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check); + if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) { + ubi_warn(ubi, "mark volume %d as corrupted", vol_id); + vol->corrupted = 1; + } + + return err; +} +EXPORT_SYMBOL_GPL(ubi_leb_read); + + +/** + * ubi_leb_read_sg - read data into a scatter gather list. + * @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 works exactly like ubi_leb_read_sg(). But instead of + * storing the read data into a buffer it writes to an UBI scatter gather + * list. + */ +int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, + 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_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); + + err = leb_read_sanity_check(desc, lnum, offset, len); + if (err < 0) + return err; + + if (len == 0) + return 0; + + err = ubi_eba_read_leb_sg(ubi, vol, sgl, lnum, offset, len, check); + if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) { + ubi_warn(ubi, "mark volume %d as corrupted", vol_id); + vol->corrupted = 1; + } + + return err; +} +EXPORT_SYMBOL_GPL(ubi_leb_read_sg); + +/** + * 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 + * + * This function writes @len bytes of data from @buf to offset @offset of + * logical eraseblock @lnum. + * + * 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) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + dbg_gen("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 (!ubi_leb_valid(vol, lnum) || offset < 0 || len < 0 || + offset + len > vol->usable_leb_size || + offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1)) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + if (len == 0) + return 0; + + return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len); +} +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 + * + * 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 than 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) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + dbg_gen("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 (!ubi_leb_valid(vol, lnum) || len < 0 || + len > vol->usable_leb_size || len & (ubi->min_io_size - 1)) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + if (len == 0) + return 0; + + return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len); +} +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; + + dbg_gen("erase LEB %d:%d", vol->vol_id, lnum); + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (!ubi_leb_valid(vol, lnum)) + 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, vol->vol_id, lnum); +} +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 than 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 than 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; + + dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum); + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (!ubi_leb_valid(vol, lnum)) + 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 eraseblock to a physical eraseblock. + * @desc: volume descriptor + * @lnum: logical eraseblock number + * + * This function maps an un-mapped logical eraseblock @lnum to a physical + * eraseblock. This means, that after a successful 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) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + + dbg_gen("map LEB %d:%d", vol->vol_id, lnum); + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (!ubi_leb_valid(vol, lnum)) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + if (ubi_eba_is_mapped(vol, lnum)) + return -EBADMSG; + + return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0); +} +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_gen("test LEB %d:%d", vol->vol_id, lnum); + + if (!ubi_leb_valid(vol, lnum)) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + return ubi_eba_is_mapped(vol, lnum); +} +EXPORT_SYMBOL_GPL(ubi_is_mapped); + +/** + * ubi_sync - synchronize UBI device buffers. + * @ubi_num: UBI device to synchronize + * + * The underlying MTD device may cache data in hardware or in software. This + * function ensures the caches are flushed. Returns zero in case of success and + * a negative error code in case of failure. + */ +int ubi_sync(int ubi_num) +{ + struct ubi_device *ubi; + + ubi = ubi_get_device(ubi_num); + if (!ubi) + return -ENODEV; + + mtd_sync(ubi->mtd); + ubi_put_device(ubi); + return 0; +} +EXPORT_SYMBOL_GPL(ubi_sync); + +/** + * ubi_flush - flush UBI work queue. + * @ubi_num: UBI device to flush work queue + * @vol_id: volume id to flush for + * @lnum: logical eraseblock number to flush for + * + * This function executes all pending works for a particular volume id / logical + * eraseblock number pair. If either value is set to %UBI_ALL, then it acts as + * a wildcard for all of the corresponding volume numbers or logical + * eraseblock numbers. It returns zero in case of success and a negative error + * code in case of failure. + */ +int ubi_flush(int ubi_num, int vol_id, int lnum) +{ + struct ubi_device *ubi; + int err = 0; + + ubi = ubi_get_device(ubi_num); + if (!ubi) + return -ENODEV; + + err = ubi_wl_flush(ubi, vol_id, lnum); + ubi_put_device(ubi); + return err; +} +EXPORT_SYMBOL_GPL(ubi_flush); + +BLOCKING_NOTIFIER_HEAD(ubi_notifiers); + +/** + * ubi_register_volume_notifier - register a volume notifier. + * @nb: the notifier description object + * @ignore_existing: if non-zero, do not send "added" notification for all + * already existing volumes + * + * This function registers a volume notifier, which means that + * 'nb->notifier_call()' will be invoked when an UBI volume is created, + * removed, re-sized, re-named, or updated. The first argument of the function + * is the notification type. The second argument is pointer to a + * &struct ubi_notification object which describes the notification event. + * Using UBI API from the volume notifier is prohibited. + * + * This function returns zero in case of success and a negative error code + * in case of failure. + */ +int ubi_register_volume_notifier(struct notifier_block *nb, + int ignore_existing) +{ + int err; + + err = blocking_notifier_chain_register(&ubi_notifiers, nb); + if (err != 0) + return err; + if (ignore_existing) + return 0; + + /* + * We are going to walk all UBI devices and all volumes, and + * notify the user about existing volumes by the %UBI_VOLUME_ADDED + * event. We have to lock the @ubi_devices_mutex to make sure UBI + * devices do not disappear. + */ + mutex_lock(&ubi_devices_mutex); + ubi_enumerate_volumes(nb); + mutex_unlock(&ubi_devices_mutex); + + return err; +} +EXPORT_SYMBOL_GPL(ubi_register_volume_notifier); + +/** + * ubi_unregister_volume_notifier - unregister the volume notifier. + * @nb: the notifier description object + * + * This function unregisters volume notifier @nm and returns zero in case of + * success and a negative error code in case of failure. + */ +int ubi_unregister_volume_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&ubi_notifiers, nb); +} +EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier); |