RE: [RFC/PATCH] mtd: ubi: Free peb's synchronously for fastmap

From: Dolev Raviv
Date: Mon Apr 07 2014 - 01:22:20 EST


Reviewed-by: Dolev Raviv <draviv@xxxxxxxxxxxxxx>

Thanks,
Dolev
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QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
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-----Original Message-----
From: linux-mtd [mailto:linux-mtd-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
Tanya Brokhman
Sent: Tuesday, April 01, 2014 11:02 AM
To: dedekind1@xxxxxxxxx
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx; open list; Tanya Brokhman
Subject: [RFC/PATCH] mtd: ubi: Free peb's synchronously for fastmap

At first mount it's possible that there are not enough free PEBs since there
are PEB's pending to be erased. In such scenario, fm_pool (which is the pool
from which user required PEBs are allocated) will be empty.
Try fixing the above described situation by synchronously performing pending
erase work, thus produce another free PEB.

Signed-off-by: Tatyana Brokhman <tlinder@xxxxxxxxxxxxxx>

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index
457ead3..9a36f78 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -595,10 +595,29 @@ static void refill_wl_pool(struct ubi_device *ubi)
static void refill_wl_user_pool(struct ubi_device *ubi) {
struct ubi_fm_pool *pool = &ubi->fm_pool;
+ int err;

return_unused_pool_pebs(ubi, pool);

for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
+retry:
+ if (!ubi->free.rb_node ||
+ (ubi->free_count - ubi->beb_rsvd_pebs < 1)) {
+ /*
+ * There are no available PEBs. Try to free
+ * PEB by means of synchronous execution of
+ * pending works.
+ */
+ if (ubi->works_count == 0)
+ break;
+ spin_unlock(&ubi->wl_lock);
+ err = do_work(ubi);
+ spin_lock(&ubi->wl_lock);
+ if (err < 0)
+ break;
+ goto retry;
+ }
+
pool->pebs[pool->size] = __wl_get_peb(ubi);
if (pool->pebs[pool->size] < 0)
break;
--
1.7.6
--
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation



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