From: Tom Rini <trini@konsulko.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] genext2fs fix for supporting filesystems generated by genext2fs
Date: Mon, 12 Dec 2016 10:48:02 -0500 [thread overview]
Message-ID: <20161212154802.GO4248@bill-the-cat> (raw)
In-Reply-To: <0VBBOyMU5FuzkvfpBlfCP7iR6SB9MaMXELTyFvZ3CnRSFC4hP95hGza2L342I6Eb-V2rK944N1EU-B61xUrwGfPsHC3R5N5Rfb_fvo3op1Q=@protonmail.com>
On Sun, Dec 11, 2016 at 07:25:21PM -0500, FrostyBytes wrote:
> I found that the latest U-Boot cannot handle filesystems generated by genext2fs. Attempts to list such a filesystem results in divide by zero.
>
> Using git bisect with a test script, I got:
>
> f798b1dda1c5de818b806189e523d1b75db7e72d is the first bad commit
>
> That commit changes to using fs->gdsize rather than a calculated descriptor size.
>
> The problem is that ext4fs_mount does not set fs->gdsize when revision_level is zero.
>
> The simplest fix seemed to be to plug in the old calculation into the case when revision_level is zero, which made the problem go away. I know next to nothing about the internals ext2/3/4, so this may not be the right thing to do. I'm attaching a patch anyways:
>
> The patch is also available at the following URL if the mailer has mangled it: https://ptpb.pw/KcQI
>
> diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
> index bfebe7e..fa83586 100644
> --- a/fs/ext4/ext4_common.c
> +++ b/fs/ext4/ext4_common.c
> @@ -2334,6 +2334,7 @@ int ext4fs_mount(unsigned part_length)
>
> if (le32_to_cpu(data->sblock.revision_level) == 0) {
> fs->inodesz = 128;
> + fs->gdsize = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
> } else {
> debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
> __le32_to_cpu(data->sblock.feature_compatibility),
Thanks for looking into this and providing the fix as well. Can you
please reply back with a Signed-off-by and your real name? Thanks!
--
Tom
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next prev parent reply other threads:[~2016-12-12 15:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-12 0:25 [U-Boot] genext2fs fix for supporting filesystems generated by genext2fs FrostyBytes
2016-12-12 15:48 ` Tom Rini [this message]
2016-12-12 23:42 ` stefan.bruens at rwth-aachen.de
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