kernel: backport 2 mtd partitioning fixes
[openwrt/openwrt.git] / target / linux / generic / backport-4.14 / 048-v4.21-mtd-improve-calculating-partition-boundaries-when-ch.patch
1 From 6750f61a13a0197c40e4a40739117493b15f19e8 Mon Sep 17 00:00:00 2001
2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
3 Date: Tue, 20 Nov 2018 10:24:09 +0100
4 Subject: [PATCH] mtd: improve calculating partition boundaries when checking
5 for alignment
6 MIME-Version: 1.0
7 Content-Type: text/plain; charset=UTF-8
8 Content-Transfer-Encoding: 8bit
9
10 When checking for alignment mtd should check absolute offsets. It's
11 important for subpartitions as it doesn't make sense to check their
12 relative addresses.
13
14 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
15 Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
16 ---
17 drivers/mtd/mtdpart.c | 13 +++++++++++--
18 1 file changed, 11 insertions(+), 2 deletions(-)
19
20 --- a/drivers/mtd/mtdpart.c
21 +++ b/drivers/mtd/mtdpart.c
22 @@ -61,6 +61,15 @@ static inline struct mtd_part *mtd_to_pa
23 return container_of(mtd, struct mtd_part, mtd);
24 }
25
26 +static u64 part_absolute_offset(struct mtd_info *mtd)
27 +{
28 + struct mtd_part *part = mtd_to_part(mtd);
29 +
30 + if (!mtd_is_partition(mtd))
31 + return 0;
32 +
33 + return part_absolute_offset(part->parent) + part->offset;
34 +}
35
36 /*
37 * MTD methods which simply translate the effective address and pass through
38 @@ -562,7 +571,7 @@ static struct mtd_part *allocate_partiti
39 if (!(slave->mtd.flags & MTD_NO_ERASE))
40 wr_alignment = slave->mtd.erasesize;
41
42 - tmp = slave->offset;
43 + tmp = part_absolute_offset(parent) + slave->offset;
44 remainder = do_div(tmp, wr_alignment);
45 if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
46 /* Doesn't start on a boundary of major erase size */
47 @@ -573,7 +582,7 @@ static struct mtd_part *allocate_partiti
48 part->name);
49 }
50
51 - tmp = slave->mtd.size;
52 + tmp = part_absolute_offset(parent) + slave->mtd.size;
53 remainder = do_div(tmp, wr_alignment);
54 if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
55 slave->mtd.flags &= ~MTD_WRITEABLE;