A given eraseblock can be read many times or not at all.
We do not have the account of such eraseblocks that have
not been accessed since a pre-defined threshold interval.
By means of scanning the entire flash device it is possible to identify
all such eraseblocks.
Add a sysfs entry to force scan on all the PEBs on demand basis.
The sysfs entry would be available under /sys/class/ubi/ubiX/peb_scan
- echo 1 to this entry would trigger the scan, ignored if in progress
- On reading returns the scan status (1 = Scan executing, 0 = Scan not
executing)
Signed-off-by: Pratibhasagar V <prati...@codeaurora.org>
Signed-off-by: Tanya Brokhman <tlin...@codeaurora.org>
---
drivers/mtd/ubi/build.c | 32 +++++++++--
drivers/mtd/ubi/ubi.h | 3 +
drivers/mtd/ubi/wl.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 171 insertions(+), 7 deletions(-)
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 34fe23a..a7464f8 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -154,6 +154,9 @@ static struct device_attribute dev_dt_threshold =
static struct device_attribute dev_rd_threshold =
__ATTR(rd_threshold, (S_IWUSR | S_IRUGO), dev_attribute_show,
dev_attribute_store);
+static struct device_attribute dev_mtd_trigger_scan =
+ __ATTR(peb_scan, (S_IWUSR | S_IRUGO),
+ dev_attribute_show, dev_attribute_store);
/**
* ubi_volume_notify - send a volume change notification.
@@ -395,6 +398,8 @@ static ssize_t dev_attribute_show(struct device *dev,
ret = sprintf(buf, "%d\n", ubi->dt_threshold);
else if (attr == &dev_rd_threshold)
ret = sprintf(buf, "%d\n", ubi->rd_threshold);
+ else if (attr == &dev_mtd_trigger_scan)
+ ret = sprintf(buf, "%d\n", ubi->scan_in_progress);
else
ret = -EINVAL;
@@ -406,7 +411,7 @@ static ssize_t dev_attribute_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
- int value;
+ int value, ret;
struct ubi_device *ubi;
ubi = container_of(dev, struct ubi_device, dev);
@@ -414,8 +419,11 @@ static ssize_t dev_attribute_store(struct device *dev,
if (!ubi)
return -ENODEV;
- if (kstrtos32(buf, 10, &value))
- return -EINVAL;
+ ret = count;
+ if (kstrtos32(buf, 10, &value)) {
+ ret = -EINVAL;
+ goto out;
+ }
/* Consider triggering full scan if threshods change */
else if (attr == &dev_dt_threshold) {
if (value < UBI_MAX_DT_THRESHOLD)
@@ -429,9 +437,21 @@ static ssize_t dev_attribute_store(struct device *dev,
else
pr_err("Max supported threshold value is %d",
UBI_MAX_READCOUNTER);
+ } else if (attr == &dev_mtd_trigger_scan) {
+ if (value != 1) {
+ pr_err("Invalid input. Echo 1 to start trigger");
+ goto out;
+ }
+ if (!ubi->lookuptbl) {
+ pr_err("lookuptbl is null");
+ goto out;
+ }
+ ret = ubi_wl_scan_all(ubi);
}
- return count;
+out:
+ ubi_put_device(ubi);
+ return ret;
}
static void dev_release(struct device *dev)
@@ -500,6 +520,9 @@ static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_rd_threshold);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_mtd_trigger_scan);
return err;
}
@@ -509,6 +532,7 @@ static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
*/
static void ubi_sysfs_close(struct ubi_device *ubi)
{
+ device_remove_file(&ubi->dev, &dev_mtd_trigger_scan);
device_remove_file(&ubi->dev, &dev_mtd_num);
device_remove_file(&ubi->dev, &dev_dt_threshold);
device_remove_file(&ubi->dev, &dev_rd_threshold);
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index ed04de2..1079517 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -491,6 +491,7 @@ struct ubi_debug_info {
* for more info
* @dt_threshold: data retention threshold. See UBI_DT_THRESHOLD
* for more info
+ * @scan_in_progress: true if scanning of device PEBs is in progress
*
* @flash_size: underlying MTD device size (in bytes)
* @peb_count: count of physical eraseblocks on the MTD device
@@ -595,6 +596,7 @@ struct ubi_device {
char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
int rd_threshold;
int dt_threshold;
+ bool scan_in_progress;
/* I/O sub-system's stuff */
@@ -873,6 +875,7 @@ int ubi_is_erase_work(struct ubi_work *wrk);
void ubi_refill_pools(struct ubi_device *ubi);
int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
int ubi_in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root);
+int ubi_wl_scan_all(struct ubi_device *ubi);
/* io.c */
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index a5d754f..4edbb4c 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -143,6 +143,8 @@ static int self_check_in_wl_tree(const struct ubi_device
*ubi,
struct ubi_wl_entry *e, struct rb_root *root);
static int self_check_in_pq(const struct ubi_device *ubi,
struct ubi_wl_entry *e);
+static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
+ int vol_id, int lnum, int torture);
#ifdef CONFIG_MTD_UBI_FASTMAP
/**
@@ -555,8 +557,11 @@ retry:
static void return_unused_pool_pebs(struct ubi_device *ubi,
struct ubi_fm_pool *pool)
{
- int i;
+ int i, err;
struct ubi_wl_entry *e;
+ struct timeval tv;
+
+ do_gettimeofday(&tv);
for (i = pool->used; i < pool->size; i++) {
e = ubi->lookuptbl[pool->pebs[i]];
@@ -566,8 +571,22 @@ static void return_unused_pool_pebs(struct ubi_device *ubi,
self_check_in_wl_tree(ubi, e, &ubi->scrub);
rb_erase(&e->u.rb, &ubi->scrub);
}
- wl_tree_add(e, &ubi->free);
- ubi->free_count++;
+ if (e->last_erase_time + UBI_DT_THRESHOLD <
+ (tv.tv_sec / NUM_SEC_IN_DAY)) {
+ spin_unlock(&ubi->wl_lock);
+ err = schedule_erase(ubi, e, UBI_UNKNOWN,
+ UBI_UNKNOWN, 0);
+ spin_lock(&ubi->wl_lock);
+ if (err) {
+ ubi_err(
+ "Failed to schedule erase for PEB %d (err=%d)",
+ e->pnum, err);
+ ubi_ro_mode(ubi);
+ }
+ } else {
+ wl_tree_add(e, &ubi->free);
+ ubi->free_count++;
+ }
}
}
@@ -711,6 +730,124 @@ int ubi_wl_get_peb(struct ubi_device *ubi)
#endif
/**
+ * ubi_wl_scan_all - Scan all PEB's
+ * @ubi: UBI device description object
+ *
+ * This function scans all device PEBs in order to locate once
+ * need scrubbing; due to read disturb threashold or last erase
+ * timestamp.
+ *
+ * Return 0 in case of sucsess, (negative) error code otherwise
+ *
+ */
+int ubi_wl_scan_all(struct ubi_device *ubi)
+{
+ struct timeval tv;
+ struct rb_node *node;
+ struct ubi_wl_entry *wl_e, *tmp;
+ int used_cnt, free_cnt;
+ int err;
+
+ do_gettimeofday(&tv);
+ if (!ubi->lookuptbl) {
+ ubi_err("lookuptbl is null");
+ return -ENOENT;
+ }
+
+ spin_lock(&ubi->wl_lock);
+ if (ubi->scan_in_progress) {
+ ubi_err("Scan already in progress, ignoring the trigger");
+ err = -EPERM;
+ goto out;
+ }
+ ubi->scan_in_progress = true;
+
+ ubi_msg("Scanning all PEBs for read-disturb/erasures");
+ /* For PEBs in free list rc=0 */
+ free_cnt = 0;
+ node = rb_first(&ubi->free);
+ while (node) {
+ wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
+ node = rb_next(node);
+ if (wl_e->last_erase_time + UBI_DT_THRESHOLD <
+ (tv.tv_sec / NUM_SEC_IN_DAY)) {
+ if (self_check_in_wl_tree(ubi, wl_e, &ubi->free)) {
+ ubi_err("PEB %d moved from free tree",
+ wl_e->pnum);
+ err = -EAGAIN;
+ goto out;
+ }
+ rb_erase(&wl_e->u.rb, &ubi->free);
+ ubi->free_count--;
+ spin_unlock(&ubi->wl_lock);
+ err = schedule_erase(ubi, wl_e, UBI_UNKNOWN,
+ UBI_UNKNOWN, 0);
+ spin_lock(&ubi->wl_lock);
+ if (err) {
+ ubi_err(
+ "Failed to schedule erase for PEB %d (err=%d)",
+ wl_e->pnum, err);
+ ubi_ro_mode(ubi);
+ goto out;
+ }
+ free_cnt++;
+ }
+ }
+
+ used_cnt = 0;
+ node = rb_first(&ubi->used);
+ while (node) {
+ wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
+ node = rb_next(node);
+ if ((wl_e->rc >= UBI_RD_THRESHOLD) ||
+ (wl_e->last_erase_time +
+ UBI_DT_THRESHOLD < (tv.tv_sec / NUM_SEC_IN_DAY))) {
+ spin_unlock(&ubi->wl_lock);
+ err = ubi_wl_scrub_peb(ubi, wl_e->pnum);
+ if (err)
+ ubi_err(
+ "Failed to schedule scrub for PEB %d (err=%d)",
+ wl_e->pnum, err);
+ else
+ used_cnt++;
+ spin_lock(&ubi->wl_lock);
+ }
+ }
+
+ /* Go over protection queue */
+ list_for_each_entry_safe(wl_e, tmp, &ubi->pq[ubi->pq_head], u.list) {
+ if ((wl_e->rc >= UBI_RD_THRESHOLD) ||
+ (wl_e->last_erase_time +
+ UBI_DT_THRESHOLD < (tv.tv_sec / NUM_SEC_IN_DAY))) {
+ spin_unlock(&ubi->wl_lock);
+ err = ubi_wl_scrub_peb(ubi, wl_e->pnum);
+ if (err)
+ ubi_err(
+ "Failed to schedule scrub for PEB %d (err=%d)",
+ wl_e->pnum, err);
+ else
+ used_cnt++;
+ spin_lock(&ubi->wl_lock);
+ }
+ }
+ spin_unlock(&ubi->wl_lock);
+ ubi_msg("Scheduled %d for erasure", free_cnt);
+ ubi_msg("Scehduled %d for scrubbing", used_cnt);
+ err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
+ if (err)
+ ubi_err("Failed to flush ubi wq. err = %d", err);
+ else
+ ubi_msg("Flashed ubi wq");
+
+ spin_lock(&ubi->wl_lock);
+out:
+ ubi->scan_in_progress = false;
+ spin_unlock(&ubi->wl_lock);
+ ubi_msg("Scanning all PEBs completed. err = %d", err);
+ return err;
+}
+
+/**
* prot_queue_del - remove a physical eraseblock from the protection queue.
* @ubi: UBI device description object
* @pnum: the physical eraseblock to remove
--
Qualcomm Israel, on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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