From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934004AbXCWQr6 (ORCPT ); Fri, 23 Mar 2007 12:47:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934081AbXCWQr6 (ORCPT ); Fri, 23 Mar 2007 12:47:58 -0400 Received: from smtp.nokia.com ([131.228.20.173]:58063 "EHLO mgw-ext14.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934004AbXCWQr4 (ORCPT ); Fri, 23 Mar 2007 12:47:56 -0400 From: Artem Bityutskiy To: Linux Kernel Mailing List Cc: Frank Haverkamp , David Woodhouse , Josh Boyer , Artem Bityutskiy Date: Fri, 23 Mar 2007 18:43:52 +0200 Message-Id: <20070323164352.8958.72437.sendpatchset@localhost.localdomain> In-Reply-To: <20070323164256.8958.58377.sendpatchset@localhost.localdomain> References: <20070323164256.8958.58377.sendpatchset@localhost.localdomain> Subject: [PATCH 11/20 take 4] UBI: kernel API functions X-OriginalArrivalTime: 23 Mar 2007 16:43:52.0381 (UTC) FILETIME=[7071B6D0:01C76D6A] X-eXpurgate-Category: 1/0 X-eXpurgate-ID: 149371::070323184411-030C9BB0-2A791E9E/0-0/0-1 X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org diff -auNrp tmp-from/drivers/mtd/ubi/kapi.c tmp-to/drivers/mtd/ubi/kapi.c --- tmp-from/drivers/mtd/ubi/kapi.c 1970-01-01 02:00:00.000000000 +0200 +++ tmp-to/drivers/mtd/ubi/kapi.c 2007-03-23 18:20:02.000000000 +0200 @@ -0,0 +1,545 @@ +/* + * 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 +#include +#include +#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 (!try_module_get(THIS_MODULE)) + return -ENODEV; + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || + !ubi_devices[ubi_num]) { + module_put(THIS_MODULE); + 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 = MKDEV(ubi->major, 0); + module_put(THIS_MODULE); + 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 = MKDEV(ubi->major, vi->vol_id + 1); +} +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 = ubi_devices[ubi_num]; + struct ubi_volume *vol; + + dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode); + + err = -ENODEV; + if (!try_module_get(THIS_MODULE)) + return ERR_PTR(err); + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi) + goto out_put; + + err = -EINVAL; + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) + goto out_put; + if (mode != UBI_READONLY && mode != UBI_READWRITE && + mode != UBI_EXCLUSIVE) + goto out_put; + + desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); + if (!desc) { + err = -ENOMEM; + goto out_put; + } + + spin_lock(&ubi->volumes_lock); + vol = ubi->volumes[vol_id]; + if (!vol) { + err = -ENODEV; + 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; + } + spin_unlock(&ubi->volumes_lock); + + desc->vol = vol; + desc->mode = mode; + + /* + * To prevent simultaneous checks of the same volume we use @vtbl_mutex, + * although it is not the purpose it was introduced for. + */ + mutex_lock(&ubi->vtbl_mutex); + if (!vol->checked) { + /* + * This is the first open - check the volume. If it is + * corrupted, still return success, but mark it as corrupted, + * so %-EUCLEAN will be returned on any further read. + */ + err = ubi_check_volume(ubi, vol_id); + if (err < 0) { + mutex_unlock(&ubi->vtbl_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->vtbl_mutex); + return desc; + +out_unlock: + spin_unlock(&ubi->volumes_lock); + kfree(desc); +out_put: + module_put(THIS_MODULE); + 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_volume_desc *ret; + 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); + + ret = ERR_PTR(-ENODEV); + if (!try_module_get(THIS_MODULE)) + return ret; + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num]) + goto out_put; + + ubi = ubi_devices[ubi_num]; + + 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) + goto out_put; + + ret = ubi_open_volume(ubi_num, vol_id, mode); + +out_put: + module_put(THIS_MODULE); + return ret; +} +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); + module_put(THIS_MODULE); +} +EXPORT_SYMBOL_GPL(ubi_close_volume); + +/** + * ubi_eraseblock_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 a corrupted UBI volume is read, this function never returns zero, but + * %-EUCLEAN is returned instead, even though the data was read without errors + * because the corruption did not affect this particular piece of data + * *otherwise %-EBADMSG would have been returned). Thus, %-EUCLEAN just means + * that the read static volume is corrupted, but the read data is actually OK. + * %-EUCLEAN is not returned for dynamic volumes, because UBI does not protect + * their contents. + * + * If the volume is damaged because of an interrupted update this function just + * returns immediately with %-EBADF error code. + */ +int ubi_eraseblock_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 (unlikely(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 (unlikely(vol->vol_type == UBI_STATIC_VOLUME && + lnum == vol->used_ebs - 1 && + offset + len > vol->last_eb_bytes)) + return -EINVAL; + + if (unlikely(vol->upd_marker)) + return -EBADF; + if (unlikely(len == 0)) + return 0; + + err = ubi_eba_read_leb(ubi, vol_id, lnum, buf, offset, len, check); + if (unlikely(err && err == -EBADMSG + && vol->vol_type == UBI_STATIC_VOLUME)) { + ubi_warn("mark volume %d as corrupted", vol_id); + vol->corrupted = 1; + err = -EUCLEAN; + } + + return err; +} +EXPORT_SYMBOL_GPL(ubi_eraseblock_read); + +/** + * ubi_eraseblock_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_eraseblock_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 (unlikely(vol_id < 0 || vol_id >= ubi->vtbl_slots)) + return -EINVAL; + + if (unlikely(desc->mode == UBI_READONLY || + vol->vol_type == UBI_STATIC_VOLUME)) + return -EROFS; + + if (unlikely(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 (unlikely(dtype != UBI_DATA_LONGTERM && + dtype != UBI_DATA_SHORTTERM && + dtype != UBI_DATA_UNKNOWN)) + return -EINVAL; + + if (unlikely(vol->upd_marker)) + return -EBADF; + + if (unlikely(len == 0)) + return 0; + + return ubi_eba_write_leb(ubi, vol_id, lnum, buf, offset, len, dtype); +} +EXPORT_SYMBOL_GPL(ubi_eraseblock_write); + +/** + * ubi_eraseblock_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_eraseblock_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 (unlikely(desc->mode == UBI_READONLY || + vol->vol_type == UBI_STATIC_VOLUME)) + return -EROFS; + + if (unlikely(lnum < 0 || lnum >= vol->reserved_pebs)) + return -EINVAL; + + if (unlikely(vol->upd_marker)) + return -EBADF; + + err = ubi_eba_unmap_leb(ubi, vol_id, lnum); + if (unlikely(err)) + return err; + + return ubi_wl_flush(ubi); +} +EXPORT_SYMBOL_GPL(ubi_eraseblock_erase); + +/** + * ubi_eraseblock_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_eraseblock_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 (unlikely(desc->mode == UBI_READONLY || + vol->vol_type == UBI_STATIC_VOLUME)) + return -EROFS; + + if (unlikely(lnum < 0 || lnum >= vol->reserved_pebs)) + return -EINVAL; + + if (unlikely(vol->upd_marker)) + return -EBADF; + + return ubi_eba_unmap_leb(ubi, vol_id, lnum); +} +EXPORT_SYMBOL_GPL(ubi_eraseblock_unmap); + +/** + * ubi_eraseblock_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_eraseblock_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 (unlikely(lnum < 0 || lnum >= vol->reserved_pebs)) + return -EINVAL; + + if (unlikely(vol->upd_marker)) + return -EBADF; + + return !!vol->eba_tbl[lnum]; +} +EXPORT_SYMBOL_GPL(ubi_eraseblock_is_mapped);