From 19371d73c9bd31a8e634ec5a80fc19fcd7714481 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Tue, 23 Sep 2014 19:29:05 +0200 Subject: [PATCH] UBI: Fastmap: Ensure that only one fastmap work is scheduled MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Tanya Brokhman Reviewed-by: Guido Martínez --- drivers/mtd/ubi/ubi.h | 4 +++- drivers/mtd/ubi/wl.c | 8 +++++++- 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++]; -- 2.11.0