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authorSebastian Siewior <bigeasy@linutronix.de>2015-11-26 21:23:50 +0100
committerRichard Weinberger <richard@nod.at>2016-01-10 12:33:11 +0100
commit34b89df90374b631692132640c6b3dbef52f808d (patch)
tree3a1e0fec6d608bf57763f94f6b92e05f0cb54ebb /drivers/mtd
parent168309855a7d1e16db751e9c647119fe2d2dc878 (diff)
downloadlinux-34b89df90374b631692132640c6b3dbef52f808d.tar.bz2
mtd: ubi: wl: avoid erasing a PEB which is empty
wear_leveling_worker() currently unconditionally puts a PEB on erase in the error case even it just been taken from the free_list and never used. In case the PEB was never used it can be put back on the free list saving a precious erase cycle. v1…v2: - to_leb_clean -> dst_leb_clean - use the nested option for ensure_wear_leveling() - do_sync_erase() can't go -ENOMEM so we can just go into RO-mode now. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/ubi/wl.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 56065632a5b8..17ec948ac40e 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -628,6 +628,7 @@ static int do_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
return __erase_worker(ubi, &wl_wrk);
}
+static int ensure_wear_leveling(struct ubi_device *ubi, int nested);
/**
* wear_leveling_worker - wear-leveling worker function.
* @ubi: UBI device description object
@@ -649,6 +650,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
#endif
struct ubi_wl_entry *e1, *e2;
struct ubi_vid_hdr *vid_hdr;
+ int dst_leb_clean = 0;
kfree(wrk);
if (shutdown)
@@ -753,6 +755,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0);
if (err && err != UBI_IO_BITFLIPS) {
+ dst_leb_clean = 1;
if (err == UBI_IO_FF) {
/*
* We are trying to move PEB without a VID header. UBI
@@ -798,10 +801,12 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
* protection queue.
*/
protect = 1;
+ dst_leb_clean = 1;
goto out_not_moved;
}
if (err == MOVE_RETRY) {
scrubbing = 1;
+ dst_leb_clean = 1;
goto out_not_moved;
}
if (err == MOVE_TARGET_BITFLIPS || err == MOVE_TARGET_WR_ERR ||
@@ -827,6 +832,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
ubi->erroneous_peb_count);
goto out_error;
}
+ dst_leb_clean = 1;
erroneous = 1;
goto out_not_moved;
}
@@ -897,15 +903,24 @@ out_not_moved:
wl_tree_add(e1, &ubi->scrub);
else
wl_tree_add(e1, &ubi->used);
+ if (dst_leb_clean) {
+ wl_tree_add(e2, &ubi->free);
+ ubi->free_count++;
+ }
+
ubi_assert(!ubi->move_to_put);
ubi->move_from = ubi->move_to = NULL;
ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
ubi_free_vid_hdr(ubi, vid_hdr);
- err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
- if (err)
- goto out_ro;
+ if (dst_leb_clean) {
+ ensure_wear_leveling(ubi, 1);
+ } else {
+ err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
+ if (err)
+ goto out_ro;
+ }
mutex_unlock(&ubi->move_mutex);
return 0;