*/
/*
- * 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
}
/**
- * 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.
+ * validate_vid_hdr - check volume identifier header.
* @vid_hdr: the volume identifier header to check
* @sv: information about the volume this logical eraseblock belongs to
* @pnum: physical eraseblock number the VID header came from
* 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.
*/
struct ubi_vid_hdr *vh = NULL;
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);
-
+ if (sqnum2 == seb->sqnum) {
/*
- * UBI constantly increases the logical eraseblock version
- * number and it can overflow. Thus, we have to bear in mind
- * 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
- * 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
- * with higher version.
- *
- * FIXME: but this is anyway obsolete and will be removed at
- * some point.
+ * This must be a really ancient UBI image which has been
+ * created before sequence numbers support has been added. At
+ * that times we used 32-bit LEB versions stored in logical
+ * eraseblocks. That was before UBI got into mainline. We do not
+ * support these images anymore. Well, those images will work
+ * still work, but only if no unclean reboots happened.
*/
+ ubi_err("unsupported on-flash UBI format\n");
+ return -EINVAL;
+ }
- dbg_bld("using old crappy leb_ver stuff");
-
- abs = v1 - v2;
- if (abs < 0)
- abs = -abs;
-
- if (abs < 0x7FFFFFFF)
- /* Non-overflow situation */
- second_is_newer = (v2 > v1);
- else
- second_is_newer = (v2 < v1);
- } else
- /* Obviously the LEB with lower sequence counter is older */
- second_is_newer = sqnum2 > seb->sqnum;
+ /* Obviously the LEB with lower sequence counter is older */
+ second_is_newer = !!(sqnum2 > seb->sqnum);
/*
* Now we know which copy is newer. If the copy flag of the PEB with
* check data CRC. For the second PEB we already have the VID header,
* for the first one - we'll need to re-read it from flash.
*
- * FIXME: this may be optimized so that we wouldn't read twice.
+ * Note: this may be optimized so that we wouldn't read twice.
*/
if (second_is_newer) {
vfree(buf);
out_free_vidh:
ubi_free_vid_hdr(ubi, vh);
- ubi_assert(err < 0);
return err;
}
/**
- * ubi_scan_add_used - add information about a physical eraseblock to the
- * scanning information.
+ * ubi_scan_add_used - add physical eraseblock to the scanning information.
* @ubi: UBI device description object
* @si: scanning information
* @pnum: the physical eraseblock number
int bitflips)
{
int err, vol_id, lnum;
- uint32_t leb_ver;
unsigned long long sqnum;
struct ubi_scan_volume *sv;
struct ubi_scan_leb *seb;
vol_id = be32_to_cpu(vid_hdr->vol_id);
lnum = be32_to_cpu(vid_hdr->lnum);
sqnum = be64_to_cpu(vid_hdr->sqnum);
- leb_ver = be32_to_cpu(vid_hdr->leb_ver);
- dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
- pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
+ dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
+ pnum, vol_id, lnum, ec, sqnum, bitflips);
sv = add_volume(si, vol_id, pnum, vid_hdr);
if (IS_ERR(sv) < 0)
*/
dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
- "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
- seb->leb_ver, seb->ec);
-
- /*
- * Make sure that the logical eraseblocks have different
- * versions. Otherwise the image is bad.
- */
- if (seb->leb_ver == leb_ver && leb_ver != 0) {
- ubi_err("two LEBs with same version %u", leb_ver);
- ubi_dbg_dump_seb(seb, 0);
- ubi_dbg_dump_vid_hdr(vid_hdr);
- return -EINVAL;
- }
+ "EC %d", seb->pnum, seb->sqnum, seb->ec);
/*
* Make sure that the logical eraseblocks have different
* sequence numbers. Otherwise the image is bad.
*
- * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
+ * However, if the sequence number is zero, we assume it must
+ * be an ancient UBI image from the era when UBI did not have
+ * sequence numbers. We still can attach these images, unless
+ * there is a need to distinguish between old and new
+ * eraseblocks, in which case we'll refuse the image in
+ * 'compare_lebs()'. In other words, we attach old clean
+ * images, but refuse attaching old images with duplicated
+ * logical eraseblocks because there was an unclean reboot.
*/
if (seb->sqnum == sqnum && sqnum != 0) {
ubi_err("two LEBs with same sequence number %llu",
seb->pnum = pnum;
seb->scrub = ((cmp_res & 2) || bitflips);
seb->sqnum = sqnum;
- seb->leb_ver = leb_ver;
if (sv->highest_lnum == lnum)
sv->last_data_size =
seb->lnum = lnum;
seb->sqnum = sqnum;
seb->scrub = bitflips;
- seb->leb_ver = leb_ver;
if (sv->highest_lnum <= lnum) {
sv->highest_lnum = lnum;
}
/**
- * ubi_scan_find_sv - find information about a particular volume in the
- * scanning information.
+ * ubi_scan_find_sv - find volume in the scanning information.
* @si: scanning information
* @vol_id: the requested volume ID
*
}
/**
- * ubi_scan_find_seb - find information about a particular logical
- * eraseblock in the volume scanning information.
+ * ubi_scan_find_seb - find LEB in the volume scanning information.
* @sv: a pointer to the volume scanning information
* @lnum: the requested logical eraseblock
*
*
* 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.
}
/**
- * process_eb - read UBI headers, check them and add corresponding data
- * to the scanning information.
+ * process_eb - read, check UBI headers, and add them to scanning information.
* @ubi: UBI device description object
* @si: scanning information
* @pnum: the physical eraseblock number
* 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");
#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
/**
- * paranoid_check_si - check if the scanning information is correct and
- * consistent.
+ * paranoid_check_si - check the scanning information.
* @ubi: UBI device description object
* @si: scanning information
*
ubi_err("bad data_pad %d", sv->data_pad);
goto bad_vid_hdr;
}
-
- if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
- ubi_err("bad leb_ver %u", seb->leb_ver);
- goto bad_vid_hdr;
- }
}
if (!last_seb)
if (err < 0) {
kfree(buf);
return err;
- }
- else if (err)
+ } else if (err)
buf[pnum] = 1;
}
git.openpandora.org / pandora-kernel.git / blobdiff