2023-02-22 01:35:43

by Wu Bo

[permalink] [raw]
Subject: [PATCH v2] docs: ext4: modify the group desc size to 64

Since the default ext4 group desc size is 64 now (assuming that the
64-bit feature is enbled). And the size mentioned in this doc is 64 too.
Change it to 64.

Signed-off-by: Wu Bo <[email protected]>
---
Documentation/filesystems/ext4/blockgroup.rst | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/filesystems/ext4/blockgroup.rst b/Documentation/filesystems/ext4/blockgroup.rst
index 46d78f860623..ed5a5cac6d40 100644
--- a/Documentation/filesystems/ext4/blockgroup.rst
+++ b/Documentation/filesystems/ext4/blockgroup.rst
@@ -105,9 +105,9 @@ descriptors. Instead, the superblock and a single block group descriptor
block is placed at the beginning of the first, second, and last block
groups in a meta-block group. A meta-block group is a collection of
block groups which can be described by a single block group descriptor
-block. Since the size of the block group descriptor structure is 32
-bytes, a meta-block group contains 32 block groups for filesystems with
-a 1KB block size, and 128 block groups for filesystems with a 4KB
+block. Since the size of the block group descriptor structure is 64
+bytes, a meta-block group contains 16 block groups for filesystems with
+a 1KB block size, and 64 block groups for filesystems with a 4KB
blocksize. Filesystems can either be created using this new block group
descriptor layout, or existing filesystems can be resized on-line, and
the field s_first_meta_bg in the superblock will indicate the first
--
2.35.3



2023-02-22 04:18:32

by Darrick J. Wong

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Subject: Re: [PATCH v2] docs: ext4: modify the group desc size to 64

On Wed, Feb 22, 2023 at 09:35:24AM +0800, Wu Bo wrote:
> Since the default ext4 group desc size is 64 now (assuming that the
> 64-bit feature is enbled). And the size mentioned in this doc is 64 too.
> Change it to 64.
>
> Signed-off-by: Wu Bo <[email protected]>

32-bit blockgroup descriptors aren't that ancient of a disk format, it's
probably helpful to mention that one should double the ratios for ^64bit
filesystems.

Also: Not sure what went wrong with your emptyish To: line?

If Ted's ok with this, then:
Acked-by: Darrick J. Wong <[email protected]>

--D

> ---
> Documentation/filesystems/ext4/blockgroup.rst | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/filesystems/ext4/blockgroup.rst b/Documentation/filesystems/ext4/blockgroup.rst
> index 46d78f860623..ed5a5cac6d40 100644
> --- a/Documentation/filesystems/ext4/blockgroup.rst
> +++ b/Documentation/filesystems/ext4/blockgroup.rst
> @@ -105,9 +105,9 @@ descriptors. Instead, the superblock and a single block group descriptor
> block is placed at the beginning of the first, second, and last block
> groups in a meta-block group. A meta-block group is a collection of
> block groups which can be described by a single block group descriptor
> -block. Since the size of the block group descriptor structure is 32
> -bytes, a meta-block group contains 32 block groups for filesystems with
> -a 1KB block size, and 128 block groups for filesystems with a 4KB
> +block. Since the size of the block group descriptor structure is 64
> +bytes, a meta-block group contains 16 block groups for filesystems with
> +a 1KB block size, and 64 block groups for filesystems with a 4KB
> blocksize. Filesystems can either be created using this new block group
> descriptor layout, or existing filesystems can be resized on-line, and
> the field s_first_meta_bg in the superblock will indicate the first
> --
> 2.35.3
>

2023-03-08 04:33:55

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH v2] docs: ext4: modify the group desc size to 64

On Wed, 22 Feb 2023 09:35:24 +0800, Wu Bo wrote:
> Since the default ext4 group desc size is 64 now (assuming that the
> 64-bit feature is enbled). And the size mentioned in this doc is 64 too.
> Change it to 64.
>
>

Applied, thanks!

[1/1] docs: ext4: modify the group desc size to 64
commit: b7eef407e5271f5135ce97bfd6e2e5009922331e

Best regards,
--
Theodore Ts'o <[email protected]>