linux-kernel - [PATCH 06/14] ubi: fastmap: Handle bad block count for preseeded fastmap case

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Date:   Wed, 13 Jun 2018 23:23:36 +0200
From:   Richard Weinberger <richard@....at>
To:     linux-mtd@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, Richard Weinberger <richard@....at>
Subject: [PATCH 06/14] ubi: fastmap: Handle bad block count for preseeded fastmap case

If the fastmap is preseeded the bad block count is created while
scanning for bad blocks in the PEB fixup code.

Signed-off-by: Richard Weinberger <richard@....at>
---
 drivers/mtd/ubi/fastmap.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 279d02874297..69b855b3cf2a 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -725,7 +725,16 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
 	}
 
 	ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
-	ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
+
+	if (fm->flags & UBI_FM_SB_PRESEEDED_FLG) {
+		/* When we have a preseeded Fastmap we cannot use the provided bad block number */
+		if (be32_to_cpu(fmhdr->bad_peb_count) != 0) {
+			ubi_err(ubi, "Bad block count in preseeded Fastmap is non-zero");
+			goto fail_bad;
+		}
+	} else {
+		ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
+	}
 
 	/* Iterate over all volumes and read their EBA table */
 	for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
-- 
2.13.6