target/linux/bcm53xx/patches-5.4/500-UBI-Detect-EOF-mark-and-erase-all-remaining-blocks.patch

From 2a2af518266a29323cf30c3f9ba9ef2ceb1dd84b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Thu, 16 Oct 2014 20:52:16 +0200
Subject: [PATCH] UBI: Detect EOF mark and erase all remaining blocks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
 drivers/mtd/ubi/attach.c | 5 +++++
 drivers/mtd/ubi/io.c     | 4 ++++
 drivers/mtd/ubi/ubi.h    | 1 +
 3 files changed, 10 insertions(+)

--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -82,6 +82,9 @@ static int self_check_ai(struct ubi_devi
 #define AV_ADD		BIT(1)
 #define AV_FIND_OR_ADD	(AV_FIND | AV_ADD)
 
+/* Set on finding block with 0xdeadc0de, indicates erasing all blocks behind */
+bool erase_all_next;
+
 /**
  * find_or_add_av - internal function to find a volume, add a volume or do
  *		    both (find and add if missing).
@@ -1580,6 +1583,8 @@ int ubi_attach(struct ubi_device *ubi, i
 	if (!ai)
 		return -ENOMEM;
 
+	erase_all_next = false;
+
 #ifdef CONFIG_MTD_UBI_FASTMAP
 	/* On small flash devices we disable fastmap in any case. */
 	if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -710,6 +710,10 @@ int ubi_io_read_ec_hdr(struct ubi_device
 	}
 
 	magic = be32_to_cpu(ec_hdr->magic);
+	if (magic == 0xdeadc0de)
+		erase_all_next = true;
+	if (erase_all_next)
+		return read_err ? UBI_IO_FF_BITFLIPS : UBI_IO_FF;
 	if (magic != UBI_EC_HDR_MAGIC) {
 		if (mtd_is_eccerr(read_err))
 			return UBI_IO_BAD_HDR_EBADMSG;
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -822,6 +822,7 @@ extern struct mutex ubi_devices_mutex;
 extern struct blocking_notifier_head ubi_notifiers;
 
 /* attach.c */
+extern bool erase_all_next;
 struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
 				   int ec);
 void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb);