*/
/*
- * UBI scanning unit.
+ * UBI scanning sub-system.
*
- * This unit is responsible for scanning the flash media, checking UBI
+ * This sub-system is responsible for scanning the flash media, checking UBI
* headers and providing complete information about the UBI flash image.
*
* The scanning information is represented by a &struct ubi_scan_info' object.
#include <linux/err.h>
#include <linux/crc32.h>
+#include <asm/div64.h>
#include "ubi.h"
#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
return 0;
}
-/**
- * commit_to_mean_value - commit intermediate results to the final mean erase
- * counter value.
- * @si: scanning information
- *
- * This is a helper function which calculates partial mean erase counter mean
- * value and adds it to the resulting mean value. As we can work only in
- * integer arithmetic and we want to calculate the mean value of erase counter
- * accurately, we first sum erase counter values in @si->ec_sum variable and
- * count these components in @si->ec_count. If this temporary @si->ec_sum is
- * going to overflow, we calculate the partial mean value
- * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
- */
-static void commit_to_mean_value(struct ubi_scan_info *si)
-{
- si->ec_sum /= si->ec_count;
- if (si->ec_sum % si->ec_count >= si->ec_count / 2)
- si->mean_ec += 1;
- si->mean_ec += si->ec_sum;
-}
-
/**
* validate_vid_hdr - check that volume identifier header is correct and
* consistent.
* non-zero if an inconsistency was found and zero if not.
*
* Note, UBI does sanity check of everything it reads from the flash media.
- * Most of the checks are done in the I/O unit. Here we check that the
+ * Most of the checks are done in the I/O sub-system. Here we check that the
* information in the VID header is consistent to the information in other VID
* headers of the same volume.
*/
unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
if (seb->sqnum == 0 && sqnum2 == 0) {
- long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
+ long long abs;
+ long long v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
/*
* UBI constantly increases the logical eraseblock version
* that versions that are close to %0xFFFFFFFF are less then
* versions that are close to %0.
*
- * The UBI WL unit guarantees that the number of pending tasks
- * is not greater then %0x7FFFFFFF. So, if the difference
+ * The UBI WL sub-system guarantees that the number of pending
+ * tasks is not greater then %0x7FFFFFFF. So, if the difference
* between any two versions is greater or equivalent to
* %0x7FFFFFFF, there was an overflow and the logical
* eraseblock with lower version is actually newer then the one
* FIXME: but this is anyway obsolete and will be removed at
* some point.
*/
-
dbg_bld("using old crappy leb_ver stuff");
+ if (v1 == v2) {
+ ubi_err("PEB %d and PEB %d have the same version %lld",
+ seb->pnum, pnum, v1);
+ return -EINVAL;
+ }
+
abs = v1 - v2;
if (abs < 0)
abs = -abs;
vfree(buf);
out_free_vidh:
ubi_free_vid_hdr(ubi, vh);
- ubi_assert(err < 0);
return err;
}
*
* This function erases physical eraseblock 'pnum', and writes the erase
* counter header to it. This function should only be used on UBI device
- * initialization stages, when the EBA unit had not been yet initialized. This
- * function returns zero in case of success and a negative error code in case
- * of failure.
+ * initialization stages, when the EBA sub-system had not been yet initialized.
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
*/
int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
int pnum, int ec)
* @si: scanning information
*
* This function returns a free physical eraseblock. It is supposed to be
- * called on the UBI initialization stages when the wear-leveling unit is not
- * initialized yet. This function picks a physical eraseblocks from one of the
- * lists, writes the EC header if it is needed, and removes it from the list.
+ * called on the UBI initialization stages when the wear-leveling sub-system is
+ * not initialized yet. This function picks a physical eraseblocks from one of
+ * the lists, writes the EC header if it is needed, and removes it from the
+ * list.
*
* This function returns scanning physical eraseblock information in case of
* success and an error code in case of failure.
* This function returns a zero if the physical eraseblock was successfully
* handled and a negative error code in case of failure.
*/
-static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
+static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
+ int pnum)
{
- long long ec;
+ long long uninitialized_var(ec);
int err, bitflips = 0, vol_id, ec_corr = 0;
dbg_bld("scan PEB %d", pnum);
return err;
else if (err) {
/*
- * FIXME: this is actually duty of the I/O unit to initialize
- * this, but MTD does not provide enough information.
+ * FIXME: this is actually duty of the I/O sub-system to
+ * initialize this, but MTD does not provide enough
+ * information.
*/
si->bad_peb_count += 1;
return 0;
}
vol_id = be32_to_cpu(vidh->vol_id);
- if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
+ if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
int lnum = be32_to_cpu(vidh->lnum);
/* Unsupported internal volume */
adjust_mean_ec:
if (!ec_corr) {
- if (si->ec_sum + ec < ec) {
- commit_to_mean_value(si);
- si->ec_sum = 0;
- si->ec_count = 0;
- } else {
- si->ec_sum += ec;
- si->ec_count += 1;
- }
-
+ si->ec_sum += ec;
+ si->ec_count += 1;
if (ec > si->max_ec)
si->max_ec = ec;
if (ec < si->min_ec)
for (pnum = 0; pnum < ubi->peb_count; pnum++) {
cond_resched();
- dbg_msg("process PEB %d", pnum);
+ dbg_gen("process PEB %d", pnum);
err = process_eb(ubi, si, pnum);
if (err < 0)
goto out_vidh;
dbg_msg("scanning is finished");
- /* Finish mean erase counter calculations */
- if (si->ec_count)
- commit_to_mean_value(si);
+ /* Calculate mean erase counter */
+ if (si->ec_count) {
+ do_div(si->ec_sum, si->ec_count);
+ si->mean_ec = si->ec_sum;
+ }
if (si->is_empty)
ubi_msg("empty MTD device detected");
if (err < 0) {
kfree(buf);
return err;
- }
- else if (err)
+ } else if (err)
buf[pnum] = 1;
}
projects / deliverable / linux.git / blobdiff