5.4-stable review patch. If anyone has any objections, please let me know.
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From: Zhihao Cheng chengzhihao1@huawei.com
commit d610020f030bec819f42de327c2bd5437d2766b3 upstream.
During wear-leveing work, the source PEB will be moved into scrub list when source LEB cannot be locked in ubi_eba_copy_leb(), which is wrong for non-scrub type source PEB. The problem could bring extra and ineffective wear-leveing jobs, which makes more or less negative effects for the life time of flash. Specifically, the process is divided 2 steps: 1. wear_leveling_worker // generate false scrub type PEB ubi_eba_copy_leb // MOVE_RETRY is returned leb_write_trylock // trylock failed scrubbing = 1; e1 is put into ubi->scrub 2. wear_leveling_worker // schedule false scrub type PEB for wl scrubbing = 1 e1 = rb_entry(rb_first(&ubi->scrub))
The problem can be reproduced easily by running fsstress on a small UBIFS partition(<64M, simulated by nandsim) for 5~10mins (CONFIG_MTD_UBI_FASTMAP=y,CONFIG_MTD_UBI_WL_THRESHOLD=50). Following message is shown: ubi0: scrubbed PEB 66 (LEB 0:10), data moved to PEB 165
Since scrub type source PEB has set variable scrubbing as '1', and variable scrubbing is checked before variable keep, so the problem can be fixed by setting keep variable as 1 directly if the source LEB cannot be locked.
Fixes: e801e128b220 ("UBI: fix missing scrub when there is a bit-flip") CC: stable@vger.kernel.org Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mtd/ubi/wl.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -824,7 +824,14 @@ static int wear_leveling_worker(struct u goto out_not_moved; } if (err == MOVE_RETRY) { - scrubbing = 1; + /* + * For source PEB: + * 1. The scrubbing is set for scrub type PEB, it will + * be put back into ubi->scrub list. + * 2. Non-scrub type PEB will be put back into ubi->used + * list. + */ + keep = 1; dst_leb_clean = 1; goto out_not_moved; }