[PATCH 30/44 take 2] [UBI] update unit implementation

Artem Bityutskiy
2007-02-17T17:01:22Z

diff -auNrp tmp-from/drivers/mtd/ubi/upd.c tmp-to/drivers/mtd/ubi/upd.c
--- tmp-from/drivers/mtd/ubi/upd.c 1970-01-01 02:00:00.000000000 +0200
+++ tmp-to/drivers/mtd/ubi/upd.c 2007-02-17 18:07:27.000000000 +0200
@@ -0,0 +1,389 @@
+/*
+ * 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 B. Bityutskiy
+ *
+ * Jan 2007: Alexander Schmidt, hacked per-volume update.
+ */
+
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <asm/uaccess.h>
+#include <asm/div64.h>
+#include "ubi.h"
+#include "upd.h"
+#include "wl.h"
+#include "vtbl.h"
+#include "io.h"
+#include "eba.h"
+#include "misc.h"
+#include "account.h"
+#include "alloc.h"
+#include "scan.h"
+#include "debug.h"
+
+static int ubi_wipe_out_volume(const struct ubi_info *ubi, int vol_id);
+
+int ubi_upd_start(const struct ubi_info *ubi, int vol_id, long long bytes)
+{
+ int err, rem;
+ uint64_t tmp;
+ const struct ubi_vtbl_vtr *vtr;
+ struct ubi_upd_info *upd = ubi->upd;
+
+ dbg_upd("start update of volume %d, %llu bytes", vol_id, bytes);
+
+ ubi_assert(vol_id >= 0 && vol_id < ubi->acc->max_volumes);
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+ ubi_assert(bytes >= 0 &&
+ bytes <= vtr->usable_leb_size * vtr->reserved_pebs);
+
+ mutex_lock(&upd->mutex);
+
+ if (upd->updating == 1) {
+ dbg_err("volume %d is being updated", upd->vol_id);
+ mutex_unlock(&upd->mutex);
+ return -EBUSY;
+ }
+
+ upd->updating = 1;
+ upd->vol_id = vol_id;
+
+ /* Set the update marker first */
+ err = ubi_vtbl_set_upd_marker(ubi, vol_id);
+ if (err)
+ goto out_unlock;
+
+ /* Before updating, we wipe out the volume */
+ err = ubi_wipe_out_volume(ubi, vol_id);
+ if (err)
+ goto out_unlock;
+
+ if (bytes == 0) {
+ /* Zero bytes means the volume just has to be erased */
+ err = ubi_vtbl_clear_upd_marker(ubi, vol_id, 0);
+ goto out_unlock;
+ }
+
+ tmp = bytes;
+ rem = do_div(tmp, vtr->usable_leb_size);
+ upd->upd_ebs = tmp + !!rem;
+ upd->upd_bytes = bytes;
+ upd->upd_received = 0;
+
+ mutex_unlock(&upd->mutex);
+ return 0;
+
+out_unlock:
+ upd->updating = 0;
+ mutex_unlock(&upd->mutex);
+ return err;
+}
+
+static int write_leb(const struct ubi_info *ubi, int vol_id, int lnum,
+ void *buf, int len, int used_ebs);
+
+int ubi_upd_write_data(const struct ubi_info *ubi, int vol_id,
+ const void __user *buf, int count)
+{
+ const struct ubi_vtbl_vtr *vtr;
+ struct ubi_upd_info *upd = ubi->upd;
+ int lnum, offs, err = 0, len;
+ uint64_t tmp;
+
+ dbg_upd("write %d bytes requested", count);
+
+ ubi_assert(vol_id >= 0 && vol_id < ubi->acc->max_volumes);
+ ubi_assert(count >= 0);
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+
+ if (unlikely(count == 0))
+ return 0;
+
+ mutex_lock(&upd->mutex);
+
+ if (unlikely(!upd->updating || upd->vol_id != vol_id)) {
+ dbg_err("volume %d update was not started", vol_id);
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ ubi_assert(upd->upd_received >= 0 &&
+ upd->upd_received < upd->upd_bytes);
+ tmp = upd->upd_received;
+ offs = do_div(tmp, vtr->usable_leb_size);
+ lnum = tmp;
+
+ if (upd->upd_received + count > upd->upd_bytes)
+ count = upd->upd_bytes - upd->upd_received;
+
+ /*
+ * When updating volumes, we accumulate whole eraseblock 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 = vtr->usable_leb_size - offs;
+ if (len > count)
+ len = count;
+
+ dbg_upd("copy more %d bytes of data", len);
+
+ err = copy_from_user(upd->upd_buf + offs, buf, len);
+ if (err) {
+ dbg_err("memory access error");
+ err = -EFAULT;
+ goto out_unlock;
+ }
+
+ if (offs + len == vtr->usable_leb_size ||
+ upd->upd_received + len == upd->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 our buffer.
+ */
+
+ ubi_assert(flush_len <= vtr->usable_leb_size);
+
+ err = write_leb(ubi, vol_id, lnum, upd->upd_buf, flush_len,
+ upd->upd_ebs);
+ if (err)
+ goto out_unlock;
+ }
+
+ upd->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) {
+ cond_resched();
+
+ if (count > vtr->usable_leb_size)
+ len = vtr->usable_leb_size;
+ else
+ len = count;
+
+ dbg_upd("copy %d bytes of user data", len);
+ err = copy_from_user(upd->upd_buf, buf, len);
+ if (err) {
+ dbg_err("memory access error");
+ err = -EFAULT;
+ goto out_unlock;
+ }
+
+ if (len == vtr->usable_leb_size ||
+ upd->upd_received + len == upd->upd_bytes) {
+ err = write_leb(ubi, vol_id, lnum, upd->upd_buf, len,
+ upd->upd_ebs);
+ if (unlikely(err))
+ break;
+ }
+
+ upd->upd_received += len;
+ count -= len;
+ lnum += 1;
+ buf += len;
+ }
+
+ ubi_assert(upd->upd_received <= upd->upd_bytes);
+ if (upd->upd_received == upd->upd_bytes) {
+ /* The update is finished, clear the update marker */
+ upd->updating = 0;
+ err = ubi_vtbl_clear_upd_marker(ubi, vol_id, upd->upd_bytes);
+ if (err == 0)
+ err = 1;
+ }
+
+out_unlock:
+ mutex_unlock(&upd->mutex);
+ return err;
+}
+
+int ubi_upd_abort(const struct ubi_info *ubi, int vol_id)
+{
+ int err = 0;
+ struct ubi_upd_info *upd = ubi->upd;
+
+ mutex_lock(&upd->mutex);
+ if (upd->updating && upd->vol_id == vol_id) {
+ dbg_upd("aborting volume %d update - it is damaged since now",
+ vol_id);
+ upd->updating = 0;
+ } else {
+ dbg_upd("volume %d is not under update", vol_id);
+ err = -EINVAL;
+ }
+ mutex_unlock(&upd->mutex);
+
+ return err;
+}
+
+int ubi_upd_init_scan(struct ubi_info *ubi, struct ubi_scan_info *si)
+{
+ int err;
+ struct ubi_upd_info *upd;
+
+ dbg_upd("initialize the update unit");
+
+ upd = ubi_kzalloc(sizeof(struct ubi_upd_info));
+ if (!upd)
+ return -ENOMEM;
+ ubi->upd = upd;
+
+ upd->upd_buf = ubi_kmalloc(ubi->io->leb_size);
+ if (!upd->upd_buf) {
+ err = -ENOMEM;
+ goto out_free_upd;
+ }
+
+ mutex_init(&upd->mutex);
+
+ dbg_upd("the update unit is initialized");
+
+ return 0;
+
+out_free_upd:
+ ubi_kfree(upd);
+ return err;
+}
+
+void ubi_upd_close(const struct ubi_info *ubi)
+{
+ dbg_upd("close the update unit");
+ ubi_kfree(ubi->upd->upd_buf);
+ ubi_kfree(ubi->upd);
+}
+
+/**
+ * ubi_wipe_out_volume - wipe out an UBI volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: ID of the volume to free
+ *
+ * This function erases all the volume's eraseblocks. Returns zero in case of
+ * success, and a negative error code in case of failure.
+ */
+static int ubi_wipe_out_volume(const struct ubi_info *ubi, int vol_id)
+{
+ int i, err;
+ const struct ubi_vtbl_vtr *vtr;
+
+ ubi_assert(vol_id >= 0 && vol_id < ubi->acc->max_volumes);
+
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ for (i = 0; i < vtr->reserved_pebs; i++) {
+ cond_resched();
+
+ err = ubi_eba_erase_leb(ubi, vol_id, i);
+ if (unlikely(err))
+ return err;
+ }
+
+ err = ubi_wl_flush(ubi);
+ return err;
+}
+
+/**
+ * write_leb - write a portion of update data to a logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID to write to
+ * @lnum: the logical eraseblock number to write
+ * @buf: the data to write
+ * @len: how many bytes to write
+ * @used_ebs: how many logical eraseblocks will this volume contain
+ *
+ * This function writes a portion of update data to the corresponding logical
+ * eraseblock. If a dynamic volume is being updated, this function checks if
+ * the data contains 0xFF bytes at the end. If yes, the 0xFF bytes are not
+ * written. If the whole buffer contains only 0xFF bytes, the LEB is left
+ * unmapped.
+ *
+ * 0xFF bytes LEBs are skipped in case of dynamic volumes because writing of
+ * 0xFF bytes may have side effects and this PEB won't be writable anymore. In
+ * case of static volume 0xFF bytes are not got rid of because static volumes
+ * are treated specially in UBI: per-LEB CRC is calculated and checked and
+ * presence of all LEBs is taken care of. So we cannot cut amount of data
+ * written to LEBs of static volume or to skip some LEBs in case of static
+ * volumes.
+ */
+static int write_leb(const struct ubi_info *ubi, int vol_id, int lnum,
+ void *buf, int len, int used_ebs)
+{
+ int err;
+ const struct ubi_vtbl_vtr *vtr;
+
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+
+ if (vtr->vol_type == UBI_DYNAMIC_VOLUME) {
+ int l;
+
+ ubi_assert(len == vtr->usable_leb_size);
+
+ /* This is dynamic volume - skip the ending 0xFFs */
+ l = ubi_calc_data_len(ubi, buf, len);
+ if (l == 0) {
+ dbg_upd("LEB %d:%d contains only 0xFF bytes - skip",
+ vol_id, lnum);
+ return 0;
+ }
+ if (len != l)
+ dbg_upd("skip last %d bytes of data for LEB %d:%d",
+ len - l, vol_id, lnum);
+
+ err = ubi_eba_write_leb(ubi, vol_id, lnum, buf, 0, l,
+ UBI_DATA_UNKNOWN);
+ } else {
+ /*
+ * When writing to static volumes, 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 needs the exact (unaligned) length to store in the
+ * VID header. And it will take 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, vtr->usable_leb_size - len);
+ err = ubi_eba_write_leb_st(ubi, vol_id, lnum, buf, len,
+ UBI_DATA_UNKNOWN, used_ebs);
+ }
+
+ return err;
+}