linux-ext4 - Re: [PATCH 23/51] e2fsck: Verify htree root/node checksums

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Date:	Mon, 19 Dec 2011 07:57:21 +0100
From:	Andreas Dilger <adilger@...mcloud.com>
To:	"Darrick J. Wong" <djwong@...ibm.com>
Cc:	Andreas Dilger <adilger.kernel@...ger.ca>,
	Theodore Tso <tytso@....edu>,
	"Darrick J. Wong" <djwong@...ibm.com>,
	Sunil Mushran <sunil.mushran@...cle.com>,
	Amir Goldstein <amir73il@...il.com>,
	Andi Kleen <andi@...stfloor.org>,
	Mingming Cao <cmm@...ibm.com>,
	Joel Becker <jlbec@...lplan.org>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
	Coly Li <colyli@...il.com>
Subject: Re: [PATCH 23/51] e2fsck: Verify htree root/node checksums

On 2011-12-14, at 2:15, "Darrick J. Wong" <djwong@...ibm.com> wrote:

> Check htree internal node checksums.  If broken, ask user to clear the htree
> index and recreate it later.
> 
> @@ -560,8 +572,12 @@ static void parse_int_node(ext2_filsys fs,
> #endif
> 
>    count = ext2fs_le16_to_cpu(limit->count);
> -    expect_limit = (fs->blocksize - ((char *) ent - block_buf)) /
> -        sizeof(struct ext2_dx_entry);
> +    if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
> +                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> +        csum_size = sizeof(struct ext2_dx_tail);
> +    expect_limit = (fs->blocksize -
> +            (csum_size + ((char *) ent - block_buf))) /
> +               sizeof(struct ext2_dx_entry);

How does this handle the case where the METADATA_CSUM feature is newly enabled but there is a dirent usinf the end of the leaf block?  It definitely shouldn't cause the last entry to be considered invalid. 

> @@ -829,7 +850,7 @@ static int check_dir_block(ext2_filsys fs,
>               (rec_len == fs->blocksize) &&
>               (dirent->name_len == 0) &&
>               (ext2fs_le16_to_cpu(limit->limit) ==
> -                ((fs->blocksize-8) /
> +                ((fs->blocksize - (8 + csum_size)) /
>                 sizeof(struct ext2_dx_entry))))
>            dx_db->type = DX_DIRBLOCK_NODE;

Same here.  

> diff --git a/e2fsck/problem.c b/e2fsck/problem.c
> index 96b0de5..2e9ab7f 100644
> --- a/e2fsck/problem.c
> +++ b/e2fsck/problem.c
> @@ -1374,6 +1374,16 @@ static struct e2fsck_problem problem_table[] = {
>      N_("i_file_acl_hi @F %N, @s zero.\n"),
>      PROMPT_CLEAR, PR_PREEN_OK },
> 
> +    /* htree root node fails checksum */
> +    { PR_2_HTREE_ROOT_CSUM_INVALID,
> +      N_("@p @h %d: root node fails checksum\n"),
> +      PROMPT_CLEAR_HTREE, PR_PREEN_OK },
> +
> +    /* htree internal node fails checksum */
> +    { PR_2_HTREE_NODE_CSUM_INVALID,
> +      N_("@p @h %d: node fails checksum\n"),

This error message should include "internal" in the printed message. 

Cheers, Andreas--
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