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authorRichard Weinberger <richard@nod.at>2014-09-23 19:29:05 +0200
committerRichard Weinberger <richard@nod.at>2015-03-26 19:30:54 +0100
commit19371d73c9bd31a8e634ec5a80fc19fcd7714481 (patch)
treee04e6910c0c98500f74afb8b92cb060404518df1 /drivers/mtd
parentab6de685221a95392e46d75d0651ac08b8a57689 (diff)
downloadlinux-19371d73c9bd31a8e634ec5a80fc19fcd7714481.tar.bz2
UBI: Fastmap: Ensure that only one fastmap work is scheduled
If the WL pool runs out of PEBs we schedule a fastmap write to refill it as soon as possible. Ensure that only one at a time is scheduled otherwise we might end in a fastmap write storm because writing the fastmap can schedule another write if bitflips are detected. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Tanya Brokhman <tlinder@codeaurora.org> Reviewed-by: Guido Martínez <guido@vanguardiasur.com.ar>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/ubi/ubi.h4
-rw-r--r--drivers/mtd/ubi/wl.c8
2 files changed, 10 insertions, 2 deletions
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 2251a6c4c8fa..7a33470c0416 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -431,6 +431,7 @@ struct ubi_debug_info {
* @fm_size: fastmap size in bytes
* @fm_sem: allows ubi_update_fastmap() to block EBA table changes
* @fm_work: fastmap work queue
+ * @fm_work_scheduled: non-zero if fastmap work was scheduled
*
* @used: RB-tree of used physical eraseblocks
* @erroneous: RB-tree of erroneous used physical eraseblocks
@@ -442,7 +443,7 @@ struct ubi_debug_info {
* @pq_head: protection queue head
* @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
* @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
- * @erroneous, and @erroneous_peb_count fields
+ * @erroneous, @erroneous_peb_count, and @fm_work_scheduled fields
* @move_mutex: serializes eraseblock moves
* @work_sem: used to wait for all the scheduled works to finish and prevent
* new works from being submitted
@@ -537,6 +538,7 @@ struct ubi_device {
void *fm_buf;
size_t fm_size;
struct work_struct fm_work;
+ int fm_work_scheduled;
/* Wear-leveling sub-system's stuff */
struct rb_root used;
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 0bd92d816391..ae174f4ed674 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -149,6 +149,9 @@ static void update_fastmap_work_fn(struct work_struct *wrk)
{
struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work);
ubi_update_fastmap(ubi);
+ spin_lock(&ubi->wl_lock);
+ ubi->fm_work_scheduled = 0;
+ spin_unlock(&ubi->wl_lock);
}
/**
@@ -657,7 +660,10 @@ static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
/* We cannot update the fastmap here because this
* function is called in atomic context.
* Let's fail here and refill/update it as soon as possible. */
- schedule_work(&ubi->fm_work);
+ if (!ubi->fm_work_scheduled) {
+ ubi->fm_work_scheduled = 1;
+ schedule_work(&ubi->fm_work);
+ }
return NULL;
} else {
pnum = pool->pebs[pool->used++];