| /* |
| * Copyright (c) International Business Machines Corp., 2006 |
| * Copyright (c) Nokia Corporation, 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) |
| * |
| * Jan 2007: Alexander Schmidt, hacked per-volume update. |
| */ |
| |
| /* |
| * This file contains implementation of the volume update and atomic LEB change |
| * functionality. |
| * |
| * The update operation is based on the per-volume update marker which is |
| * stored in the volume table. The update marker is set before the update |
| * starts, and removed after the update has been finished. So if the update was |
| * interrupted by an unclean re-boot or due to some other reasons, the update |
| * marker stays on the flash media and UBI finds it when it attaches the MTD |
| * device next time. If the update marker is set for a volume, the volume is |
| * treated as damaged and most I/O operations are prohibited. Only a new update |
| * operation is allowed. |
| * |
| * Note, in general it is possible to implement the update operation as a |
| * transaction with a roll-back capability. |
| */ |
| |
| #include <linux/err.h> |
| #include <asm/uaccess.h> |
| #include <asm/div64.h> |
| #include "ubi.h" |
| |
| /** |
| * set_update_marker - set update marker. |
| * @ubi: UBI device description object |
| * @vol: volume description object |
| * |
| * This function sets the update marker flag for volume @vol. Returns zero |
| * in case of success and a negative error code in case of failure. |
| */ |
| static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol) |
| { |
| int err; |
| struct ubi_vtbl_record vtbl_rec; |
| |
| dbg_msg("set update marker for volume %d", vol->vol_id); |
| |
| if (vol->upd_marker) { |
| ubi_assert(ubi->vtbl[vol->vol_id].upd_marker); |
| dbg_msg("already set"); |
| return 0; |
| } |
| |
| memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], |
| sizeof(struct ubi_vtbl_record)); |
| vtbl_rec.upd_marker = 1; |
| |
| mutex_lock(&ubi->volumes_mutex); |
| err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
| mutex_unlock(&ubi->volumes_mutex); |
| vol->upd_marker = 1; |
| return err; |
| } |
| |
| /** |
| * clear_update_marker - clear update marker. |
| * @ubi: UBI device description object |
| * @vol: volume description object |
| * @bytes: new data size in bytes |
| * |
| * This function clears the update marker for volume @vol, sets new volume |
| * data size and clears the "corrupted" flag (static volumes only). Returns |
| * zero in case of success and a negative error code in case of failure. |
| */ |
| static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol, |
| long long bytes) |
| { |
| int err; |
| uint64_t tmp; |
| struct ubi_vtbl_record vtbl_rec; |
| |
| dbg_msg("clear update marker for volume %d", vol->vol_id); |
| |
| memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], |
| sizeof(struct ubi_vtbl_record)); |
| ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); |
| vtbl_rec.upd_marker = 0; |
| |
| if (vol->vol_type == UBI_STATIC_VOLUME) { |
| vol->corrupted = 0; |
| vol->used_bytes = tmp = bytes; |
| vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size); |
| vol->used_ebs = tmp; |
| if (vol->last_eb_bytes) |
| vol->used_ebs += 1; |
| else |
| vol->last_eb_bytes = vol->usable_leb_size; |
| } |
| |
| mutex_lock(&ubi->volumes_mutex); |
| err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
| mutex_unlock(&ubi->volumes_mutex); |
| vol->upd_marker = 0; |
| return err; |
| } |
| |
| /** |
| * ubi_start_update - start volume update. |
| * @ubi: UBI device description object |
| * @vol: volume description object |
| * @bytes: update bytes |
| * |
| * This function starts volume update operation. If @bytes is zero, the volume |
| * is just wiped out. Returns zero in case of success and a negative error code |
| * in case of failure. |
| */ |
| int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, |
| long long bytes) |
| { |
| int i, err; |
| uint64_t tmp; |
| |
| dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes); |
| ubi_assert(!vol->updating && !vol->changing_leb); |
| vol->updating = 1; |
| |
| err = set_update_marker(ubi, vol); |
| if (err) |
| return err; |
| |
| /* Before updating - wipe out the volume */ |
| for (i = 0; i < vol->reserved_pebs; i++) { |
| err = ubi_eba_unmap_leb(ubi, vol, i); |
| if (err) |
| return err; |
| } |
| |
| if (bytes == 0) { |
| err = clear_update_marker(ubi, vol, 0); |
| if (err) |
| return err; |
| err = ubi_wl_flush(ubi); |
| if (!err) |
| vol->updating = 0; |
| } |
| |
| vol->upd_buf = vmalloc(ubi->leb_size); |
| if (!vol->upd_buf) |
| return -ENOMEM; |
| |
| tmp = bytes; |
| vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size); |
| vol->upd_ebs += tmp; |
| vol->upd_bytes = bytes; |
| vol->upd_received = 0; |
| return 0; |
| } |
| |
| /** |
| * ubi_start_leb_change - start atomic LEB change. |
| * @ubi: UBI device description object |
| * @vol: volume description object |
| * @req: operation request |
| * |
| * This function starts atomic LEB change operation. Returns zero in case of |
| * success and a negative error code in case of failure. |
| */ |
| int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, |
| const struct ubi_leb_change_req *req) |
| { |
| ubi_assert(!vol->updating && !vol->changing_leb); |
| |
| dbg_msg("start changing LEB %d:%d, %u bytes", |
| vol->vol_id, req->lnum, req->bytes); |
| if (req->bytes == 0) |
| return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0, |
| req->dtype); |
| |
| vol->upd_bytes = req->bytes; |
| vol->upd_received = 0; |
| vol->changing_leb = 1; |
| vol->ch_lnum = req->lnum; |
| vol->ch_dtype = req->dtype; |
| |
| vol->upd_buf = vmalloc(req->bytes); |
| if (!vol->upd_buf) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| /** |
| * write_leb - write update data. |
| * @ubi: UBI device description object |
| * @vol: volume description object |
| * @lnum: logical eraseblock number |
| * @buf: data to write |
| * @len: data size |
| * @used_ebs: how many logical eraseblocks will this volume contain (static |
| * volumes only) |
| * |
| * This function writes update data to corresponding logical eraseblock. In |
| * case of dynamic volume, this function checks if the data contains 0xFF bytes |
| * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole |
| * buffer contains only 0xFF bytes, the LEB is left unmapped. |
| * |
| * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is |
| * that we want to make sure that more data may be appended to the logical |
| * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and |
| * this PEB won't be writable anymore. So if one writes the file-system image |
| * to the UBI volume where 0xFFs mean free space - UBI makes sure this free |
| * space is writable after the update. |
| * |
| * We do not do this for static volumes because they are read-only. But this |
| * also cannot be done because we have to store per-LEB CRC and the correct |
| * data length. |
| * |
| * This function returns zero in case of success and a negative error code in |
| * case of failure. |
| */ |
| static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, |
| void *buf, int len, int used_ebs) |
| { |
| int err; |
| |
| if (vol->vol_type == UBI_DYNAMIC_VOLUME) { |
| int l = ALIGN(len, ubi->min_io_size); |
| |
| memset(buf + len, 0xFF, l - len); |
| len = ubi_calc_data_len(ubi, buf, l); |
| if (len == 0) { |
| dbg_msg("all %d bytes contain 0xFF - skip", len); |
| return 0; |
| } |
| |
| err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN); |
| } else { |
| /* |
| * When writing static volume, and this is the last logical |
| * eraseblock, the length (@len) does not have to be aligned to |
| * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' |
| * function accepts exact (unaligned) length and stores it in |
| * the VID header. And it takes care of proper alignment by |
| * padding the buffer. Here we just make sure the padding will |
| * contain zeros, not random trash. |
| */ |
| memset(buf + len, 0, vol->usable_leb_size - len); |
| err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, |
| UBI_UNKNOWN, used_ebs); |
| } |
| |
| return err; |
| } |
| |
| /** |
| * ubi_more_update_data - write more update data. |
| * @vol: volume description object |
| * @buf: write data (user-space memory buffer) |
| * @count: how much bytes to write |
| * |
| * This function writes more data to the volume which is being updated. It may |
| * be called arbitrary number of times until all the update data arriveis. This |
| * function returns %0 in case of success, number of bytes written during the |
| * last call if the whole volume update has been successfully finished, and a |
| * negative error code in case of failure. |
| */ |
| int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, |
| const void __user *buf, int count) |
| { |
| uint64_t tmp; |
| int lnum, offs, err = 0, len, to_write = count; |
| |
| dbg_msg("write %d of %lld bytes, %lld already passed", |
| count, vol->upd_bytes, vol->upd_received); |
| |
| if (ubi->ro_mode) |
| return -EROFS; |
| |
| tmp = vol->upd_received; |
| offs = do_div(tmp, vol->usable_leb_size); |
| lnum = tmp; |
| |
| if (vol->upd_received + count > vol->upd_bytes) |
| to_write = count = vol->upd_bytes - vol->upd_received; |
| |
| /* |
| * When updating volumes, we accumulate whole logical eraseblock of |
| * data and write it at once. |
| */ |
| if (offs != 0) { |
| /* |
| * This is a write to the middle of the logical eraseblock. We |
| * copy the data to our update buffer and wait for more data or |
| * flush it if the whole eraseblock is written or the update |
| * is finished. |
| */ |
| |
| len = vol->usable_leb_size - offs; |
| if (len > count) |
| len = count; |
| |
| err = copy_from_user(vol->upd_buf + offs, buf, len); |
| if (err) |
| return -EFAULT; |
| |
| if (offs + len == vol->usable_leb_size || |
| vol->upd_received + len == vol->upd_bytes) { |
| int flush_len = offs + len; |
| |
| /* |
| * OK, we gathered either the whole eraseblock or this |
| * is the last chunk, it's time to flush the buffer. |
| */ |
| ubi_assert(flush_len <= vol->usable_leb_size); |
| err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len, |
| vol->upd_ebs); |
| if (err) |
| return err; |
| } |
| |
| vol->upd_received += len; |
| count -= len; |
| buf += len; |
| lnum += 1; |
| } |
| |
| /* |
| * If we've got more to write, let's continue. At this point we know we |
| * are starting from the beginning of an eraseblock. |
| */ |
| while (count) { |
| if (count > vol->usable_leb_size) |
| len = vol->usable_leb_size; |
| else |
| len = count; |
| |
| err = copy_from_user(vol->upd_buf, buf, len); |
| if (err) |
| return -EFAULT; |
| |
| if (len == vol->usable_leb_size || |
| vol->upd_received + len == vol->upd_bytes) { |
| err = write_leb(ubi, vol, lnum, vol->upd_buf, |
| len, vol->upd_ebs); |
| if (err) |
| break; |
| } |
| |
| vol->upd_received += len; |
| count -= len; |
| lnum += 1; |
| buf += len; |
| } |
| |
| ubi_assert(vol->upd_received <= vol->upd_bytes); |
| if (vol->upd_received == vol->upd_bytes) { |
| /* The update is finished, clear the update marker */ |
| err = clear_update_marker(ubi, vol, vol->upd_bytes); |
| if (err) |
| return err; |
| err = ubi_wl_flush(ubi); |
| if (err == 0) { |
| vol->updating = 0; |
| err = to_write; |
| vfree(vol->upd_buf); |
| } |
| } |
| |
| return err; |
| } |
| |
| /** |
| * ubi_more_leb_change_data - accept more data for atomic LEB change. |
| * @vol: volume description object |
| * @buf: write data (user-space memory buffer) |
| * @count: how much bytes to write |
| * |
| * This function accepts more data to the volume which is being under the |
| * "atomic LEB change" operation. It may be called arbitrary number of times |
| * until all data arrives. This function returns %0 in case of success, number |
| * of bytes written during the last call if the whole "atomic LEB change" |
| * operation has been successfully finished, and a negative error code in case |
| * of failure. |
| */ |
| int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, |
| const void __user *buf, int count) |
| { |
| int err; |
| |
| dbg_msg("write %d of %lld bytes, %lld already passed", |
| count, vol->upd_bytes, vol->upd_received); |
| |
| if (ubi->ro_mode) |
| return -EROFS; |
| |
| if (vol->upd_received + count > vol->upd_bytes) |
| count = vol->upd_bytes - vol->upd_received; |
| |
| err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count); |
| if (err) |
| return -EFAULT; |
| |
| vol->upd_received += count; |
| |
| if (vol->upd_received == vol->upd_bytes) { |
| int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size); |
| |
| memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes); |
| len = ubi_calc_data_len(ubi, vol->upd_buf, len); |
| err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum, |
| vol->upd_buf, len, UBI_UNKNOWN); |
| if (err) |
| return err; |
| } |
| |
| ubi_assert(vol->upd_received <= vol->upd_bytes); |
| if (vol->upd_received == vol->upd_bytes) { |
| vol->changing_leb = 0; |
| err = count; |
| vfree(vol->upd_buf); |
| } |
| |
| return err; |
| } |