openwrt/target/linux/generic/pending-4.14/510-f2fs-fix-sanity_check_raw_super-on-big-endian-machines.patch
Christian Lamparter cb0f39c9cd kernel: fix f2fs on big endian machines
The WD MyBook Live SquashFS images didn't work anymore due to
a upstream regression in f2fs commit: 0cfe75c5b01199
("f2fs: enhance sanity_check_raw_super() to avoid potential overflows")
that got backported to 4.14.86 and landed in 4.18.

by Martin Blumenstingl:
|Treat "block_count" from struct f2fs_super_block as 64-bit little endian
|value in sanity_check_raw_super() because struct f2fs_super_block
|declares "block_count" as "__le64".
|
|This fixes a bug where the superblock validation fails on big endian
|devices with the following error:
|  F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0)
|  F2FS-fs (sda1): Can't find valid F2FS filesystem in 1th superblock
|  F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0)
|  F2FS-fs (sda1): Can't find valid F2FS filesystem in 2th superblock
|As result of this the partition cannot be mounted.
|
|With this patch applied the superblock validation works fine and the
|partition can be mounted again:
|  F2FS-fs (sda1): Mounted with checkpoint version = 7c84
|
|My little endian x86-64 hardware was able to mount the partition without
|this fix.
|To confirm that mounting f2fs filesystems works on big endian machines
|again I tested this on a 32-bit MIPS big endian (lantiq) device.

Hopefully, this will do until Martin's patch moved through upstream
to -stable.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
2018-12-29 13:41:35 +01:00

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2.1 KiB
Diff

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: linux-f2fs-devel@lists.sourceforge.net, yuchao0@huawei.com,
jaegeuk@kernel.org
Subject: [PATCH v2 1/1] f2fs: fix validation of the block count in
sanity_check_raw_super
Date: Sat, 22 Dec 2018 11:22:26 +0100
Message-Id: <20181222102226.10050-2-martin.blumenstingl@googlemail.com>
Treat "block_count" from struct f2fs_super_block as 64-bit little endian
value in sanity_check_raw_super() because struct f2fs_super_block
declares "block_count" as "__le64".
This fixes a bug where the superblock validation fails on big endian
devices with the following error:
F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0)
F2FS-fs (sda1): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0)
F2FS-fs (sda1): Can't find valid F2FS filesystem in 2th superblock
As result of this the partition cannot be mounted.
With this patch applied the superblock validation works fine and the
partition can be mounted again:
F2FS-fs (sda1): Mounted with checkpoint version = 7c84
My little endian x86-64 hardware was able to mount the partition without
this fix.
To confirm that mounting f2fs filesystems works on big endian machines
again I tested this on a 32-bit MIPS big endian (lantiq) device.
Fixes: 0cfe75c5b01199 ("f2fs: enhance sanity_check_raw_super() to avoid potential overflows")
Cc: stable@vger.kernel.org
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
---
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1897,10 +1897,10 @@ static int sanity_check_raw_super(struct
return 1;
}
- if (segment_count > (le32_to_cpu(raw_super->block_count) >> 9)) {
+ if (segment_count > (le64_to_cpu(raw_super->block_count) >> 9)) {
f2fs_msg(sb, KERN_INFO,
- "Wrong segment_count / block_count (%u > %u)",
- segment_count, le32_to_cpu(raw_super->block_count));
+ "Wrong segment_count / block_count (%u > %llu)",
+ segment_count, le64_to_cpu(raw_super->block_count));
return 1;
}