From: Ted Ts'o <tytso@mit.edu>
To: "Darrick J. Wong" <djwong@us.ibm.com>, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 02/22] ext4: Create a rocompat flag for extended metadata checksumming
Date: Mon, 5 Dec 2011 10:41:33 -0500 [thread overview]
Message-ID: <20111205154133.GA5488@thunk.org> (raw)
In-Reply-To: <20111128232629.19194.43499.stgit@elm3c44.beaverton.ibm.com>
(Reviews sent to ext4 list only)
On Mon, Nov 28, 2011 at 03:26:29PM -0800, Darrick J. Wong wrote:
> This patch introduces a rocompat feature flag to signal the presence
> of checksums for metadata blocks. It also provides storage for a
> precomputed UUID checksum.
>
> +
> + /* Precomputed FS UUID checksum */
> + __u32 s_uuid_csum;
This is really a checksum seed, right? Calling it a UUID is going to
be confusing because UUID's are expected to be 128 bits, and something
which is 32 bits can't possibly be a universally unique.
I'd suggest calling this "s_csum_seed", and we explain it as a
random seed which is selected when the file system is formatted.
The commit description could also explain that this is used so we can
detect old metadata blocks left over from a previous use of the
storage device.
- Ted
next prev parent reply other threads:[~2011-12-05 15:41 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-28 23:26 [PATCH v2.1 00/22] ext4: Add metadata checksumming Darrick J. Wong
2011-11-28 23:26 ` [PATCH 01/22] ext4: Create a new BH_Verified flag to avoid unnecessary metadata validation Darrick J. Wong
2011-11-28 23:26 ` [PATCH 02/22] ext4: Create a rocompat flag for extended metadata checksumming Darrick J. Wong
2011-12-05 15:41 ` Ted Ts'o [this message]
2011-12-05 19:24 ` Darrick J. Wong
2011-11-28 23:26 ` [PATCH 03/22] ext4: Record the checksum algorithm in use in the superblock Darrick J. Wong
2011-12-05 15:46 ` Ted Ts'o
2011-12-05 19:32 ` Darrick J. Wong
[not found] ` <E0964BB6-793D-49AF-A2B0-20748C6DAE2B@dilger.ca>
2011-12-07 7:42 ` Darrick J. Wong
2011-12-07 8:40 ` Andreas Dilger
2011-11-28 23:26 ` [PATCH 04/22] ext4: Only call out to crc32c if necessary Darrick J. Wong
2011-12-05 15:52 ` Ted Ts'o
2011-12-05 19:38 ` Darrick J. Wong
2011-11-28 23:26 ` [PATCH 05/22] ext4: Calculate and verify superblock checksum Darrick J. Wong
2011-11-28 23:26 ` [PATCH 06/22] ext4: Calculate and verify inode checksums Darrick J. Wong
2011-12-05 16:24 ` Ted Ts'o
2011-12-05 19:45 ` Darrick J. Wong
2011-11-28 23:27 ` [PATCH 07/22] ext4: Create bitmap checksum helper functions Darrick J. Wong
2011-12-05 16:33 ` Ted Ts'o
2011-12-05 20:31 ` Darrick J. Wong
2011-12-05 23:54 ` Darrick J. Wong
2011-12-06 17:19 ` Andreas Dilger
2011-12-06 20:59 ` Darrick J. Wong
2011-11-28 23:27 ` [PATCH 08/22] ext4: Calculate and verify checksums for inode bitmaps Darrick J. Wong
2011-11-28 23:27 ` [PATCH 09/22] ext4: Calculate and verify block bitmap checksum Darrick J. Wong
2011-11-28 23:27 ` [PATCH 10/22] ext4: Verify and calculate checksums for extent tree blocks Darrick J. Wong
2011-12-05 16:40 ` Ted Ts'o
2011-12-05 19:50 ` Darrick J. Wong
2011-11-28 23:27 ` [PATCH 11/22] ext4: Calculate and verify checksums for htree nodes Darrick J. Wong
2011-11-28 23:27 ` [PATCH 12/22] ext4: Calculate and verify checksums of directory leaf blocks Darrick J. Wong
2011-11-28 23:27 ` [PATCH 13/22] ext4: Calculate and verify checksums of extended attribute blocks Darrick J. Wong
2011-11-28 23:27 ` [PATCH 14/22] ext4: Add new feature to make block group checksums use metadata_csum algorithm Darrick J. Wong
2011-11-28 23:28 ` [PATCH 15/22] ext4: Add checksums to the MMP block Darrick J. Wong
2011-11-28 23:28 ` [PATCH 16/22] jbd2: Update structure definitions and flags to support extended checksumming Darrick J. Wong
2011-11-28 23:28 ` [PATCH 17/22] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
2011-11-28 23:28 ` [PATCH 18/22] jbd2: Update structure definitions and flags to support extended checksumming Darrick J. Wong
2011-11-28 23:28 ` [PATCH 19/22] jbd2: Checksum revocation blocks Darrick J. Wong
2011-12-12 15:39 ` Ted Ts'o
2011-11-28 23:28 ` [PATCH 20/22] jbd2: Checksum descriptor blocks Darrick J. Wong
2011-11-28 23:28 ` [PATCH 21/22] jbd2: Checksum commit blocks Darrick J. Wong
2011-11-28 23:28 ` [PATCH 22/22] jbd2: Checksum data blocks that are stored in the journal Darrick J. Wong
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