[RFC/PATCH 2/5] mtd: ubi: Fill read disturb statistics

From: Tanya Brokhman
Date: Sun Sep 28 2014 - 02:37:38 EST

From: Tatyana Brokhman <tlinder@xxxxxxxxxxxxxx>

Fill in eraseblock statistics needed for read disturb decision making:
1. read counter: incremented at each read operation
reset at each erase operation
Saved only as part of the meta data in RAM
On attach: if fastmap data is missing a default value is assigned
2. last erase time stamp: updated at each erase operation.
Saved as part of PEB OOB info on flash
On attach: if fastmap data is missing retrieved from PEB EC Header
on NAND.
If fastmap data is corrupted a default value is assigned.

The above parameters are saved as part of the fastmap data.

Signed-off-by: Tatyana Brokhman <tlinder@xxxxxxxxxxxxxx>
Signed-off-by: Dolev Raviv <draviv@xxxxxxxxxxxxxx>
---
drivers/mtd/ubi/attach.c | 137 +++++++++++++++++++++++++++++++++++-----------
drivers/mtd/ubi/debug.c | 11 ++++
drivers/mtd/ubi/fastmap.c | 118 ++++++++++++++++++++++++++++++++++-----
drivers/mtd/ubi/io.c | 28 ++++++++++
drivers/mtd/ubi/ubi.h | 24 +++++++-
drivers/mtd/ubi/vtbl.c | 6 +-
drivers/mtd/ubi/wl.c | 47 ++++++++++++++++
7 files changed, 322 insertions(+), 49 deletions(-)

diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
index 6f27d9a..e102cac 100644
--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -1,5 +1,8 @@
/*
* Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) 2014, Linux Foundation. All rights reserved.
+ * Linux Foundation chooses to take subject only to the GPLv2
+ * license terms, and distributes only under these terms.
*
* 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
@@ -87,8 +90,21 @@
#include <linux/crc32.h>
#include <linux/math64.h>
#include <linux/random.h>
+#include <linux/time.h>
#include "ubi.h"

+#define set_aeb_default_values(aeb, ai) \
+ do { \
+ if (aeb->ec == UBI_UNKNOWN) { \
+ aeb->ec = ai->mean_ec; \
+ if (ai->mean_last_erase_time) \
+ aeb->last_erase_time = \
+ ai->mean_last_erase_time; \
+ else \
+ aeb->last_erase_time = UBI_DT_THRESHOLD / 2; \
+ } \
+ } while (0)
+
static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);

/* Temporary variables used during scanning */
@@ -102,6 +118,9 @@ static struct ubi_vid_hdr *vidh;
* @vol_id: the last used volume id for the PEB
* @lnum: the last used LEB number for the PEB
* @ec: erase counter of the physical eraseblock
+ * @last_erase_time: last erase time stamp (%UBI_UNKNOWN if it
+ * is unknown)
+ * @rc: read counter (%UBI_UNKNOWN if it is unknown)
* @to_head: if not zero, add to the head of the list
* @list: the list to add to
*
@@ -117,7 +136,8 @@ static struct ubi_vid_hdr *vidh;
* failure.
*/
static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,
- int lnum, int ec, int to_head, struct list_head *list)
+ int lnum, int ec, long last_erase_time, long rc,
+ int to_head, struct list_head *list)
{
struct ubi_ainf_peb *aeb;

@@ -139,6 +159,9 @@ static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,
aeb->vol_id = vol_id;
aeb->lnum = lnum;
aeb->ec = ec;
+ aeb->rc = rc;
+ aeb->last_erase_time = last_erase_time;
+
if (to_head)
list_add(&aeb->u.list, list);
else
@@ -151,13 +174,17 @@ static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,
* @ai: attaching information
* @pnum: physical eraseblock number to add
* @ec: erase counter of the physical eraseblock
+ * @last_erase_time: last erase time stamp (%UBI_UNKNOWN if it
+ * is unknown)
+ * @rc: read counter (%UBI_UNKNOWN if it is unknown)
*
* This function allocates a 'struct ubi_ainf_peb' object for a corrupted
* physical eraseblock @pnum and adds it to the 'corr' list. The corruption
* was presumably not caused by a power cut. Returns zero in case of success
* and a negative error code in case of failure.
*/
-static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
+static int add_corrupted(struct ubi_attach_info *ai, int pnum,
+ int ec, long rc, long last_erase_time)
{
struct ubi_ainf_peb *aeb;

@@ -170,6 +197,8 @@ static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
ai->corr_peb_count += 1;
aeb->pnum = pnum;
aeb->ec = ec;
+ aeb->rc = rc;
+ aeb->last_erase_time = last_erase_time;
list_add(&aeb->u.list, &ai->corr);
return 0;
}
@@ -434,6 +463,9 @@ out_free_vidh:
* @ai: attaching information
* @pnum: the physical eraseblock number
* @ec: erase counter
+ * @last_erase_time: last erase time stamp (%UBI_UNKNOWN if it
+ * is unknown)
+ * @rc: read counter (%UBI_UNKNOWN if it is unknown)
* @vid_hdr: the volume identifier header
* @bitflips: if bit-flips were detected when this physical eraseblock was read
*
@@ -445,7 +477,8 @@ out_free_vidh:
* zero in case of success and a negative error code in case of failure.
*/
int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
- int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
+ int ec, long last_erase_time, long rc,
+ const struct ubi_vid_hdr *vid_hdr, int bitflips)
{
int err, vol_id, lnum;
unsigned long long sqnum;
@@ -532,12 +565,16 @@ int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
return err;

err = add_to_list(ai, aeb->pnum, aeb->vol_id,
- aeb->lnum, aeb->ec, cmp_res & 4,
+ aeb->lnum, aeb->ec,
+ aeb->last_erase_time,
+ aeb->rc, cmp_res & 4,
&ai->erase);
if (err)
return err;

aeb->ec = ec;
+ aeb->last_erase_time = last_erase_time;
+ aeb->rc = rc;
aeb->pnum = pnum;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
@@ -556,7 +593,8 @@ int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
* previously.
*/
return add_to_list(ai, pnum, vol_id, lnum, ec,
- cmp_res & 4, &ai->erase);
+ last_erase_time, rc, cmp_res & 4,
+ &ai->erase);
}
}

@@ -574,6 +612,8 @@ int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
return -ENOMEM;

aeb->ec = ec;
+ aeb->last_erase_time = last_erase_time;
+ aeb->rc = rc;
aeb->pnum = pnum;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
@@ -650,6 +690,8 @@ void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
* @ai: attaching information
* @pnum: physical eraseblock number to erase;
* @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
+ * @last_erase_time: last erase time stamp (%UBI_UNKNOWN if it
+ * is unknown)
*
* This function erases physical eraseblock 'pnum', and writes the erase
* counter header to it. This function should only be used on UBI device
@@ -658,7 +700,8 @@ void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
* case of failure.
*/
static int early_erase_peb(struct ubi_device *ubi,
- const struct ubi_attach_info *ai, int pnum, int ec)
+ const struct ubi_attach_info *ai,
+ int pnum, int ec, long last_erase_time)
{
int err;
struct ubi_ec_hdr *ec_hdr;
@@ -677,7 +720,7 @@ static int early_erase_peb(struct ubi_device *ubi,
return -ENOMEM;

ec_hdr->ec = cpu_to_be64(ec);
-
+ ec_hdr->last_erase_time = cpu_to_be64(last_erase_time);
err = ubi_io_sync_erase(ubi, pnum, 0);
if (err < 0)
goto out_free;
@@ -708,6 +751,7 @@ struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
{
int err = 0;
struct ubi_ainf_peb *aeb, *tmp_aeb;
+ struct timeval tv;

if (!list_empty(&ai->free)) {
aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
@@ -722,15 +766,20 @@ struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
* so forth. We don't want to take care about bad eraseblocks here -
* they'll be handled later.
*/
+ do_gettimeofday(&tv);
list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
if (aeb->ec == UBI_UNKNOWN)
aeb->ec = ai->mean_ec;

- err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
+ /* The last erase time resolution is in days */
+ err = early_erase_peb(ubi, ai, aeb->pnum,
+ aeb->ec+1, tv.tv_sec / NUM_SEC_IN_DAY);
if (err)
continue;

aeb->ec += 1;
+ aeb->last_erase_time = tv.tv_sec / NUM_SEC_IN_DAY;
+ aeb->rc = 0;
list_del(&aeb->u.list);
dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
return aeb;
@@ -817,6 +866,8 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
int pnum, int *vid, unsigned long long *sqnum)
{
long long uninitialized_var(ec);
+ long long uninitialized_var(rc);
+ long long uninitialized_var(last_erase_time);
int err, bitflips = 0, vol_id = -1, ec_err = 0;

dbg_bld("scan PEB %d", pnum);
@@ -842,11 +893,13 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
case UBI_IO_FF:
ai->empty_peb_count += 1;
return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
- UBI_UNKNOWN, 0, &ai->erase);
+ UBI_UNKNOWN, UBI_UNKNOWN, UBI_UNKNOWN,
+ 0, &ai->erase);
case UBI_IO_FF_BITFLIPS:
ai->empty_peb_count += 1;
return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
- UBI_UNKNOWN, 1, &ai->erase);
+ UBI_UNKNOWN, UBI_UNKNOWN, UBI_UNKNOWN,
+ 1, &ai->erase);
case UBI_IO_BAD_HDR_EBADMSG:
case UBI_IO_BAD_HDR:
/*
@@ -856,6 +909,8 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
*/
ec_err = err;
ec = UBI_UNKNOWN;
+ last_erase_time = UBI_UNKNOWN;
+ rc = UBI_UNKNOWN;
bitflips = 1;
break;
default:
@@ -874,6 +929,16 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
}

ec = be64_to_cpu(ech->ec);
+ last_erase_time = be64_to_cpu(ech->last_erase_time);
+ /*
+ * Default value for read counter should be 0. If this is a
+ * free or erased peb, the counter has no meaning.
+ * If this peb is used, later code will schedule the peb for
+ * scrubbing. We can afford erasing all used blocks in this
+ * case as this is a rear case, and not doing so might have
+ * destructive implication on the system.
+ */
+ rc = 0;
if (ec > UBI_MAX_ERASECOUNTER) {
/*
* Erase counter overflow. The EC headers have 64 bits
@@ -957,29 +1022,32 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
else if (!err)
/* This corruption is caused by a power cut */
err = add_to_list(ai, pnum, UBI_UNKNOWN,
- UBI_UNKNOWN, ec, 1, &ai->erase);
+ UBI_UNKNOWN, ec, last_erase_time, rc,
+ 1, &ai->erase);
else
/* This is an unexpected corruption */
- err = add_corrupted(ai, pnum, ec);
+ err = add_corrupted(ai, pnum, ec, rc, last_erase_time);
if (err)
return err;
- goto adjust_mean_ec;
+ goto adjust_mean_av_stat;
case UBI_IO_FF_BITFLIPS:
err = add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
- ec, 1, &ai->erase);
+ ec, last_erase_time, rc, 1, &ai->erase);
if (err)
return err;
- goto adjust_mean_ec;
+ goto adjust_mean_av_stat;
case UBI_IO_FF:
if (ec_err || bitflips)
err = add_to_list(ai, pnum, UBI_UNKNOWN,
- UBI_UNKNOWN, ec, 1, &ai->erase);
+ UBI_UNKNOWN, ec, last_erase_time, rc,
+ 1, &ai->erase);
else
err = add_to_list(ai, pnum, UBI_UNKNOWN,
- UBI_UNKNOWN, ec, 0, &ai->free);
+ UBI_UNKNOWN, ec, last_erase_time, 0,
+ 0, &ai->free);
if (err)
return err;
- goto adjust_mean_ec;
+ goto adjust_mean_av_stat;
default:
ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
err);
@@ -1003,7 +1071,8 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
vol_id, lnum);
}
err = add_to_list(ai, pnum, vol_id, lnum,
- ec, 1, &ai->erase);
+ ec, last_erase_time,
+ rc, 1, &ai->erase);
if (err)
return err;
return 0;
@@ -1018,7 +1087,8 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
ubi_msg("\"preserve\" compatible internal volume %d:%d found",
vol_id, lnum);
err = add_to_list(ai, pnum, vol_id, lnum,
- ec, 0, &ai->alien);
+ ec, last_erase_time,
+ rc, 0, &ai->alien);
if (err)
return err;
return 0;
@@ -1033,11 +1103,13 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
if (ec_err)
ubi_warn("valid VID header but corrupted EC header at PEB %d",
pnum);
- err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
+
+ err = ubi_add_to_av(ubi, ai, pnum, ec, last_erase_time,
+ UBI_DEF_RD_THRESHOLD, vidh, bitflips);
if (err)
return err;

-adjust_mean_ec:
+adjust_mean_av_stat:
if (!ec_err) {
ai->ec_sum += ec;
ai->ec_count += 1;
@@ -1045,6 +1117,8 @@ adjust_mean_ec:
ai->max_ec = ec;
if (ec < ai->min_ec)
ai->min_ec = ec;
+ ai->last_erase_time_sum += last_erase_time;
+ ai->last_erase_time_count++;
}

return 0;
@@ -1254,6 +1328,10 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
if (ai->ec_count)
ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);

+ if (ai->last_erase_time_count)
+ ai->mean_last_erase_time = div_u64(ai->last_erase_time_sum,
+ ai->last_erase_time_count);
+
err = late_analysis(ubi, ai);
if (err)
goto out_vidh;
@@ -1264,22 +1342,17 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
*/
ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
+ set_aeb_default_values(aeb, ai);
}

- list_for_each_entry(aeb, &ai->free, u.list) {
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
- }
+ list_for_each_entry(aeb, &ai->free, u.list)
+ set_aeb_default_values(aeb, ai);

list_for_each_entry(aeb, &ai->corr, u.list)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
+ set_aeb_default_values(aeb, ai);

list_for_each_entry(aeb, &ai->erase, u.list)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
+ set_aeb_default_values(aeb, ai);

err = self_check_ai(ubi, ai);
if (err)
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 63cb1d7..d172c7c 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -1,5 +1,8 @@
/*
* Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) 2014, Linux Foundation. All rights reserved.
+ * Linux Foundation chooses to take subject only to the GPLv2
+ * license terms, and distributes only under these terms.
*
* 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
@@ -47,6 +50,14 @@ void ubi_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
err, len, pnum, offset, read);
goto out;
}
+ if (ubi->lookuptbl) {
+ if (ubi->lookuptbl[pnum]->rc < UBI_MAX_READCOUNTER)
+ ubi->lookuptbl[pnum]->rc++;
+ else
+ ubi_err("read counter overflow at PEB %d, RC %d",
+ pnum, ubi->lookuptbl[pnum]->rc);
+ } else
+ ubi_err("Can't update RC. No lookuptbl");

ubi_msg("dumping %d bytes of data from PEB %d, offset %d",
len, pnum, offset);
diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 5399aa2..f72980b 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -31,6 +31,7 @@ size_t ubi_calc_fm_size(struct ubi_device *ubi)
sizeof(struct ubi_fm_scan_pool) + \
(ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
(sizeof(struct ubi_fm_eba) + \
+ (ubi->peb_count * sizeof(__be32)) + \
(ubi->peb_count * sizeof(__be32))) + \
sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
return roundup(size, ubi->leb_size);
@@ -71,12 +72,16 @@ out:
* @list: the target list
* @pnum: PEB number of the new attach erase block
* @ec: erease counter of the new LEB
+ * @last_erase_time: last erase time stamp (%UBI_UNKNOWN if it
+ * is unknown)
+ * @rc: read counter (%UBI_UNKNOWN if it is unknown)
* @scrub: scrub this PEB after attaching
*
* Returns 0 on success, < 0 indicates an internal error.
*/
static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
- int pnum, int ec, int scrub)
+ int pnum, int ec, unsigned long last_erase_time,
+ int rc, int scrub)
{
struct ubi_ainf_peb *aeb;

@@ -86,6 +91,8 @@ static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,

aeb->pnum = pnum;
aeb->ec = ec;
+ aeb->rc = rc;
+ aeb->last_erase_time = last_erase_time;
aeb->lnum = -1;
aeb->scrub = scrub;
aeb->copy_flag = aeb->sqnum = 0;
@@ -99,6 +106,9 @@ static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
if (ai->min_ec > aeb->ec)
ai->min_ec = aeb->ec;

+ ai->last_erase_time_sum += aeb->last_erase_time;
+ ai->last_erase_time_count++;
+
list_add_tail(&aeb->u.list, list);

return 0;
@@ -246,6 +256,8 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
return -ENOMEM;

victim->ec = aeb->ec;
+ victim->last_erase_time = aeb->last_erase_time;
+ victim->rc = aeb->rc;
victim->pnum = aeb->pnum;
list_add_tail(&victim->u.list, &ai->erase);

@@ -257,6 +269,8 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
av->vol_id, aeb->lnum, new_aeb->pnum);

aeb->ec = new_aeb->ec;
+ aeb->last_erase_time = new_aeb->last_erase_time;
+ aeb->rc = new_aeb->rc;
aeb->pnum = new_aeb->pnum;
aeb->copy_flag = new_vh->copy_flag;
aeb->scrub = new_aeb->scrub;
@@ -271,7 +285,7 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,

return 0;
}
- /* This LEB is new, let's add it to the volume */
+ /* This LEB is new, last_erase_time's add it to the volume */

if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
av->highest_lnum = be32_to_cpu(new_vh->lnum);
@@ -444,12 +458,16 @@ static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
unsigned long long ec = be64_to_cpu(ech->ec);
+ unsigned long long last_erase_time =
+ be64_to_cpu(ech->last_erase_time);
unmap_peb(ai, pnum);
dbg_bld("Adding PEB to free: %i", pnum);
if (err == UBI_IO_FF_BITFLIPS)
- add_aeb(ai, free, pnum, ec, 1);
+ add_aeb(ai, free, pnum, ec, last_erase_time,
+ 0, 1);
else
- add_aeb(ai, free, pnum, ec, 0);
+ add_aeb(ai, free, pnum, ec, last_erase_time,
+ 0, 0);
continue;
} else if (err == 0 || err == UBI_IO_BITFLIPS) {
dbg_bld("Found non empty PEB:%i in pool", pnum);
@@ -477,6 +495,9 @@ static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
}

new_aeb->ec = be64_to_cpu(ech->ec);
+ new_aeb->last_erase_time =
+ be64_to_cpu(ech->last_erase_time);
+ new_aeb->rc = UBI_DEF_RD_THRESHOLD;
new_aeb->pnum = pnum;
new_aeb->lnum = be32_to_cpu(vh->lnum);
new_aeb->sqnum = be64_to_cpu(vh->sqnum);
@@ -649,7 +670,9 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
goto fail_bad;

add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
- be32_to_cpu(fmec->ec), 0);
+ be32_to_cpu(fmec->ec),
+ be64_to_cpu(fmec->last_erase_time),
+ be32_to_cpu(fmec->rc), 0);
}

/* read EC values from used list */
@@ -660,7 +683,9 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
goto fail_bad;

add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
- be32_to_cpu(fmec->ec), 0);
+ be32_to_cpu(fmec->ec),
+ be64_to_cpu(fmec->last_erase_time),
+ be32_to_cpu(fmec->rc), 0);
}

/* read EC values from scrub list */
@@ -671,7 +696,9 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
goto fail_bad;

add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
- be32_to_cpu(fmec->ec), 1);
+ be32_to_cpu(fmec->ec),
+ be64_to_cpu(fmec->last_erase_time),
+ be32_to_cpu(fmec->rc), 1);
}

/* read EC values from erase list */
@@ -682,10 +709,14 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
goto fail_bad;

add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
- be32_to_cpu(fmec->ec), 1);
+ be32_to_cpu(fmec->ec),
+ be64_to_cpu(fmec->last_erase_time),
+ be32_to_cpu(fmec->rc), 1);
}

ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
+ ai->mean_last_erase_time = div_u64(ai->last_erase_time_sum,
+ ai->last_erase_time_count);
ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);

/* Iterate over all volumes and read their EBA table */
@@ -717,7 +748,8 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,

fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
fm_pos += sizeof(*fm_eba);
- fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
+ fm_pos += 2 * (sizeof(__be32) *
+ be32_to_cpu(fm_eba->reserved_pebs));
if (fm_pos >= fm_size)
goto fail_bad;

@@ -761,7 +793,9 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
aeb->lnum = j;
aeb->pnum =
be32_to_cpu(fm_eba->peb_data[j].pnum);
- aeb->ec = -1;
+ aeb->ec = UBI_UNKNOWN;
+ aeb->rc = be32_to_cpu(fm_eba->peb_data[j].rc);
+ aeb->last_erase_time = UBI_UNKNOWN;
aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
list_add_tail(&aeb->u.list, &eba_orphans);
continue;
@@ -807,6 +841,9 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
tmp_aeb->scrub = 1;

tmp_aeb->ec = be64_to_cpu(ech->ec);
+ tmp_aeb->last_erase_time =
+ be64_to_cpu(ech->last_erase_time);
+ tmp_aeb->rc = UBI_DEF_RD_THRESHOLD;
assign_aeb_to_av(ai, tmp_aeb, av);
}

@@ -1062,6 +1099,8 @@ int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,

e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
e->ec = be32_to_cpu(fmsb2->block_ec[i]);
+ e->last_erase_time = be64_to_cpu(fmsb2->block_let[i]);
+ e->rc = be32_to_cpu(fmsb2->block_rc[i]);
fm->e[i] = e;
}

@@ -1179,7 +1218,8 @@ static int ubi_write_fastmap(struct ubi_device *ubi,

fec->pnum = cpu_to_be32(wl_e->pnum);
fec->ec = cpu_to_be32(wl_e->ec);
-
+ fec->last_erase_time = cpu_to_be64(wl_e->last_erase_time);
+ fec->rc = cpu_to_be32(wl_e->rc);
free_peb_count++;
fm_pos += sizeof(*fec);
ubi_assert(fm_pos <= ubi->fm_size);
@@ -1192,7 +1232,8 @@ static int ubi_write_fastmap(struct ubi_device *ubi,

fec->pnum = cpu_to_be32(wl_e->pnum);
fec->ec = cpu_to_be32(wl_e->ec);
-
+ fec->last_erase_time = cpu_to_be64(wl_e->last_erase_time);
+ fec->rc = cpu_to_be32(wl_e->rc);
used_peb_count++;
fm_pos += sizeof(*fec);
ubi_assert(fm_pos <= ubi->fm_size);
@@ -1205,6 +1246,8 @@ static int ubi_write_fastmap(struct ubi_device *ubi,

fec->pnum = cpu_to_be32(wl_e->pnum);
fec->ec = cpu_to_be32(wl_e->ec);
+ fec->last_erase_time = cpu_to_be64(wl_e->last_erase_time);
+ fec->rc = cpu_to_be32(wl_e->rc);

scrub_peb_count++;
fm_pos += sizeof(*fec);
@@ -1222,6 +1265,9 @@ static int ubi_write_fastmap(struct ubi_device *ubi,

fec->pnum = cpu_to_be32(wl_e->pnum);
fec->ec = cpu_to_be32(wl_e->ec);
+ fec->last_erase_time =
+ cpu_to_be64(wl_e->last_erase_time);
+ fec->rc = cpu_to_be32(wl_e->rc);

erase_peb_count++;
fm_pos += sizeof(*fec);
@@ -1257,8 +1303,15 @@ static int ubi_write_fastmap(struct ubi_device *ubi,
2 * (sizeof(__be32) * vol->reserved_pebs);
ubi_assert(fm_pos <= ubi->fm_size);

- for (j = 0; j < vol->reserved_pebs; j++)
+ for (j = 0; j < vol->reserved_pebs; j++) {
feba->peb_data[j].pnum = cpu_to_be32(vol->eba_tbl[j]);
+ feba->peb_data[j].rc = cpu_to_be32(UBI_UNKNOWN);
+ if (vol->eba_tbl[j] >= 0 &&
+ ubi->lookuptbl[vol->eba_tbl[j]])
+ feba->peb_data[j].rc =
+ cpu_to_be32(
+ ubi->lookuptbl[vol->eba_tbl[j]]->rc);
+ }

feba->reserved_pebs = cpu_to_be32(j);
feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
@@ -1282,6 +1335,8 @@ static int ubi_write_fastmap(struct ubi_device *ubi,
for (i = 0; i < new_fm->used_blocks; i++) {
fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
+ fmsb->block_let[i] = cpu_to_be64(new_fm->e[i]->last_erase_time);
+ fmsb->block_rc[i] = cpu_to_be32(new_fm->e[i]->rc);
}

fmsb->data_crc = 0;
@@ -1335,6 +1390,7 @@ static int erase_block(struct ubi_device *ubi, int pnum)
int ret;
struct ubi_ec_hdr *ec_hdr;
long long ec;
+ struct timeval tv;

ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
if (!ec_hdr)
@@ -1360,6 +1416,9 @@ static int erase_block(struct ubi_device *ubi, int pnum)
}

ec_hdr->ec = cpu_to_be64(ec);
+ do_gettimeofday(&tv);
+ /* The last erase time resolution is in days */
+ ec_hdr->last_erase_time = cpu_to_be64(tv.tv_sec / NUM_SEC_IN_DAY);
ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
if (ret < 0)
goto out;
@@ -1382,10 +1441,17 @@ static int invalidate_fastmap(struct ubi_device *ubi,
{
int ret;
struct ubi_vid_hdr *vh;
+ struct timeval tv;

ret = erase_block(ubi, fm->e[0]->pnum);
if (ret < 0)
return ret;
+ fm->e[0]->ec = ret;
+
+ do_gettimeofday(&tv);
+ /* The last erase time resolution is in days */
+ fm->e[0]->last_erase_time = tv.tv_sec / NUM_SEC_IN_DAY;
+ fm->e[0]->rc = 0;

vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
if (!vh)
@@ -1412,6 +1478,9 @@ int ubi_update_fastmap(struct ubi_device *ubi)
int ret, i;
struct ubi_fastmap_layout *new_fm, *old_fm;
struct ubi_wl_entry *tmp_e;
+ struct timeval tv;
+
+ do_gettimeofday(&tv);

mutex_lock(&ubi->fm_mutex);

@@ -1485,10 +1554,19 @@ int ubi_update_fastmap(struct ubi_device *ubi)
}

new_fm->e[i]->pnum = old_fm->e[i]->pnum;
- new_fm->e[i]->ec = old_fm->e[i]->ec;
+ new_fm->e[i]->ec = old_fm->e[i]->ec = ret;
+
+ /* The last erase time resolution is in days */
+ new_fm->e[i]->last_erase_time =
+ tv.tv_sec / NUM_SEC_IN_DAY;
+ old_fm->e[i]->last_erase_time =
+ tv.tv_sec / NUM_SEC_IN_DAY;
+ new_fm->e[i]->rc = old_fm->e[i]->rc = 0;
} else {
new_fm->e[i]->pnum = tmp_e->pnum;
new_fm->e[i]->ec = tmp_e->ec;
+ new_fm->e[i]->rc = tmp_e->rc;
+ new_fm->e[i]->last_erase_time = tmp_e->last_erase_time;

if (old_fm)
ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
@@ -1515,7 +1593,13 @@ int ubi_update_fastmap(struct ubi_device *ubi)
}

new_fm->e[0]->pnum = old_fm->e[0]->pnum;
- new_fm->e[0]->ec = ret;
+ new_fm->e[0]->ec = old_fm->e[0]->ec = ret;
+ /* The last erase time resolution is in days */
+ new_fm->e[0]->last_erase_time =
+ tv.tv_sec / NUM_SEC_IN_DAY;
+ old_fm->e[0]->last_erase_time =
+ tv.tv_sec / NUM_SEC_IN_DAY;
+ new_fm->e[0]->rc = old_fm->e[0]->rc = 0;
} else {
/* we've got a new anchor PEB, return the old one */
ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
@@ -1523,6 +1607,8 @@ int ubi_update_fastmap(struct ubi_device *ubi)

new_fm->e[0]->pnum = tmp_e->pnum;
new_fm->e[0]->ec = tmp_e->ec;
+ new_fm->e[0]->last_erase_time = tmp_e->last_erase_time;
+ new_fm->e[0]->rc = tmp_e->rc;
}
} else {
if (!tmp_e) {
@@ -1538,6 +1624,8 @@ int ubi_update_fastmap(struct ubi_device *ubi)

new_fm->e[0]->pnum = tmp_e->pnum;
new_fm->e[0]->ec = tmp_e->ec;
+ new_fm->e[0]->last_erase_time = tmp_e->last_erase_time;
+ new_fm->e[0]->rc = tmp_e->rc;
}

down_write(&ubi->work_sem);
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index d361349..444d552 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1,6 +1,9 @@
/*
* Copyright (c) International Business Machines Corp., 2006
* Copyright (c) Nokia Corporation, 2006, 2007
+ * Copyright (c) 2014, Linux Foundation. All rights reserved.
+ * Linux Foundation chooses to take subject only to the GPLv2
+ * license terms, and distributes only under these terms.
*
* 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
@@ -204,6 +207,14 @@ retry:
}
} else {
ubi_assert(len == read);
+ if (ubi->lookuptbl && ubi->lookuptbl[pnum]) {
+ if (ubi->lookuptbl[pnum]->rc <
+ UBI_MAX_READCOUNTER)
+ ubi->lookuptbl[pnum]->rc++;
+ else
+ ubi_err("read counter overflow at PEB %d, RC %d",
+ pnum, ubi->lookuptbl[pnum]->rc);
+ }

if (ubi_dbg_is_bitflip(ubi)) {
dbg_gen("bit-flip (emulated)");
@@ -1337,6 +1348,15 @@ static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
if (err && !mtd_is_bitflip(err))
goto out_free;

+ if (ubi->lookuptbl && ubi->lookuptbl[pnum]) {
+ if (ubi->lookuptbl[pnum]->rc < UBI_MAX_READCOUNTER)
+ ubi->lookuptbl[pnum]->rc++;
+ else
+ ubi_err("read counter overflow at PEB %d, RC %d",
+ pnum, ubi->lookuptbl[pnum]->rc);
+ } else
+ ubi_err("Can't update RC. No lookuptbl");
+
for (i = 0; i < len; i++) {
uint8_t c = ((uint8_t *)buf)[i];
uint8_t c1 = ((uint8_t *)buf1)[i];
@@ -1403,6 +1423,14 @@ int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
err, len, pnum, offset, read);
goto error;
}
+ if (ubi->lookuptbl && ubi->lookuptbl[pnum]) {
+ if (ubi->lookuptbl[pnum]->rc < UBI_MAX_READCOUNTER)
+ ubi->lookuptbl[pnum]->rc++;
+ else
+ ubi_err("read counter overflow at PEB %d, RC %d",
+ pnum, ubi->lookuptbl[pnum]->rc);
+ } else
+ ubi_err("Can't update RC. No lookuptbl");

err = ubi_check_pattern(buf, 0xFF, len);
if (err == 0) {
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 6c7e53e..e4c97ad 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -95,6 +95,16 @@
#define UBI_RD_THRESHOLD 100000

/*
+ * This is the default read counter to be assigned to blocks lacking
+ * read counter value on attach. The value was choosen as mean between
+ * just_erased_block (rc = 0) and needs_scrubbibg_block
+ * (rc = UBI_RD_THRESHOLD). On the one hand we don't want to miss
+ * blocks that needs scrubbing but on the other, we dont want to
+ * abuse scrubbing.
+ */
+#define UBI_DEF_RD_THRESHOLD (UBI_RD_THRESHOLD / 2)
+
+/*
* This parameter defines the maximun interval (in days) between two
* erasures of an eraseblock. When this interval is reached, UBI starts
* performing wear leveling by means of moving data from eraseblock with
@@ -102,6 +112,9 @@
*/
#define UBI_DT_THRESHOLD 120

+/* Used when calculaing the lats erase timestamp of a PEB */
+#define NUM_SEC_IN_DAY (60*60*24)
+
/*
* The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
* + 2 for the number plus 1 for the trailing zero byte.
@@ -709,6 +722,11 @@ struct ubi_ainf_volume {
* @ec_sum: a temporary variable used when calculating @mean_ec
* @ec_count: a temporary variable used when calculating @mean_ec
* @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
+ * @mean_last_erase_time: mean late erase timestamp value
+ * @last_erase_time_sum: temporary variable, used to calculate
+ * @mean_last_erase_time
+ * @last_erase_time_count: temporary variable, used to calculate
+ * @mean_last_erase_time
*
* This data structure contains the result of attaching an MTD device and may
* be used by other UBI sub-systems to build final UBI data structures, further
@@ -735,6 +753,9 @@ struct ubi_attach_info {
uint64_t ec_sum;
int ec_count;
struct kmem_cache *aeb_slab_cache;
+ long long mean_last_erase_time;
+ long long last_erase_time_sum;
+ int last_erase_time_count;
};

/**
@@ -775,7 +796,8 @@ extern struct blocking_notifier_head ubi_notifiers;

/* attach.c */
int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
- int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
+ int ec, long last_erase_time, long rc,
+ const struct ubi_vid_hdr *vid_hdr, int bitflips);
struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
int vol_id);
void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 07cac5f..625a9b4 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -1,6 +1,9 @@
/*
* Copyright (c) International Business Machines Corp., 2006
* Copyright (c) Nokia Corporation, 2006, 2007
+ * Copyright (c) 2014, Linux Foundation. All rights reserved.
+ * Linux Foundation chooses to take subject only to the GPLv2
+ * license terms, and distributes only under these terms.
*
* 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
@@ -339,7 +342,8 @@ retry:
* And add it to the attaching information. Don't delete the old version
* of this LEB as it will be deleted and freed in 'ubi_add_to_av()'.
*/
- err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0);
+ err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec,
+ new_aeb->last_erase_time, new_aeb->rc, vid_hdr, 0);
kmem_cache_free(ai->aeb_slab_cache, new_aeb);
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 33d33e43..2b4e6fe 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -105,6 +105,7 @@
#include <linux/crc32.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
+#include <linux/time.h>
#include "ubi.h"

/* Number of physical eraseblocks reserved for wear-leveling purposes */
@@ -742,6 +743,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
int err;
struct ubi_ec_hdr *ec_hdr;
unsigned long long ec = e->ec;
+ struct timeval tv;

dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec);

@@ -773,11 +775,16 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,

ec_hdr->ec = cpu_to_be64(ec);

+ do_gettimeofday(&tv);
+ /* The last erase time resolution is in days */
+ ec_hdr->last_erase_time = cpu_to_be64(tv.tv_sec / NUM_SEC_IN_DAY);
err = ubi_io_write_ec_hdr(ubi, e->pnum, ec_hdr);
if (err)
goto out_free;

e->ec = ec;
+ e->last_erase_time = tv.tv_sec / NUM_SEC_IN_DAY;
+ e->rc = 0;
spin_lock(&ubi->wl_lock);
if (e->ec > ubi->max_ec)
ubi->max_ec = e->ec;
@@ -979,6 +986,8 @@ int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e,
ubi->lookuptbl[pnum] = e;
} else {
e->ec = fm_e->ec;
+ e->rc = fm_e->rc;
+ e->last_erase_time = fm_e->last_erase_time;
kfree(fm_e);
}

@@ -1913,6 +1922,19 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)

e->pnum = aeb->pnum;
e->ec = aeb->ec;
+ e->last_erase_time = aeb->last_erase_time;
+ e->rc = aeb->rc;
+ if (!ubi->fm) {
+ if (e->rc < UBI_MAX_READCOUNTER) {
+ e->rc++;
+ } else {
+ ubi_err("read counter overflow at PEB %d, RC %d",
+ e->pnum, e->rc);
+ kmem_cache_free(ubi_wl_entry_slab, e);
+ goto out_free;
+ }
+
+ }
ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
ubi->lookuptbl[e->pnum] = e;
if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {
@@ -1933,6 +1955,19 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)

e->pnum = aeb->pnum;
e->ec = aeb->ec;
+ e->rc = aeb->rc;
+ if (!ubi->fm) {
+ if (e->rc < UBI_MAX_READCOUNTER) {
+ e->rc++;
+ } else {
+ ubi_err("rc overflow at PEB %d, RC %d",
+ e->pnum, e->rc);
+ kmem_cache_free(ubi_wl_entry_slab, e);
+ goto out_free;
+ }
+
+ }
+ e->last_erase_time = aeb->last_erase_time;
ubi_assert(e->ec >= 0);
ubi_assert(!ubi_is_fm_block(ubi, e->pnum));

@@ -1954,6 +1989,18 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)

e->pnum = aeb->pnum;
e->ec = aeb->ec;
+ e->rc = aeb->rc;
+ if (!ubi->fm) {
+ if (e->rc < UBI_MAX_READCOUNTER) {
+ e->rc++;
+ } else {
+ ubi_err("rc overflow at PEB %d, RC %d",
+ e->pnum, e->rc);
+ kmem_cache_free(ubi_wl_entry_slab, e);
+ goto out_free;
+ }
+ }
+ e->last_erase_time = aeb->last_erase_time;
ubi->lookuptbl[e->pnum] = e;

if (!aeb->scrub) {
--
1.8.5.2
--
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/