From: "Theodore Ts'o" <tytso@mit.edu>
To: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/13] ext4: correct gdblock calculation in add_new_gdb_meta_bg to support non first group
Date: Fri, 18 Aug 2023 12:54:32 -0400 [thread overview]
Message-ID: <20230818165432.GB3515079@mit.edu> (raw)
In-Reply-To: <797c2dff-1858-9e4b-bda7-d6106d5ff844@huaweicloud.com>
On Fri, Aug 18, 2023 at 03:09:35PM +0800, Kemeng Shi wrote:
> > Is following comment looks good to you:
>
> When all reserved primary blocks are consumed, we create meta_bg group and
> allocate new primary block at first block or block after backup superblock
> (if exsiting) in first group of meta_bg group.
> This function is only called when first group of meta_bg is added.
Well, it's possible to create a file system where all of the block
group descriptors use meta_bg, and there are no "traditional" block
group descriptors. And so what happens is if there is no available
space in the existing block group descriptors for the new block group,
and there are no reserved block group descriptors (I'd remove
"primary" as that's not something that we've used traditionally), then
what happens is that the meta_bg feature will get enabled, and
es->s_first_meta_bg will get set to the first block group that is
managed using meta_bg. s_first_meta_bg must be a multiple of
EXT4_DESC_PER_BLOCK(sb).
Some of this is documented in Documentation/filesystems/ext4/blockgroup.rst
already.
Cheers,
- Ted
next prev parent reply other threads:[~2023-08-18 16:55 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-29 12:00 [PATCH 00/13] fixes and cleanups to ext4 resize Kemeng Shi
2023-06-29 12:00 ` [PATCH 01/13] ext4: correct offset of gdb backup in non meta_bg group to update_backups Kemeng Shi
2023-08-16 3:03 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 02/13] ext4: add missed brelse in update_backups Kemeng Shi
2023-08-16 3:03 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 03/13] ext4: correct return value of ext4_convert_meta_bg Kemeng Shi
2023-08-16 3:00 ` Theodore Ts'o
2023-08-17 2:48 ` Kemeng Shi
2023-08-17 13:58 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 04/13] ext4: remove gdb backup copy for meta bg in setup_new_flex_group_blocks Kemeng Shi
2023-08-16 3:10 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 05/13] ext4: fix typo " Kemeng Shi
2023-08-16 3:10 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 06/13] ext4: remove redundant check of count Kemeng Shi
2023-08-16 3:14 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 07/13] ext4: remove commented code in reserve_backup_gdb Kemeng Shi
2023-08-16 3:14 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 08/13] ext4: calculate free_clusters_count in cluster unit in verify_group_input Kemeng Shi
2023-08-16 3:22 ` Theodore Ts'o
2023-08-17 2:57 ` Kemeng Shi
2023-06-29 12:00 ` [PATCH 09/13] ext4: remove EXT4FS_DEBUG defination in resize.c Kemeng Shi
2023-08-16 3:23 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 10/13] ext4: use saved local variable sbi instead of EXT4_SB(sb) Kemeng Shi
2023-08-16 3:24 ` Theodore Ts'o
2023-06-29 12:00 ` [PATCH 11/13] ext4: correct gdblock calculation in add_new_gdb_meta_bg to support non first group Kemeng Shi
2023-08-16 3:45 ` Theodore Ts'o
2023-08-17 3:38 ` Kemeng Shi
2023-08-17 14:03 ` Theodore Ts'o
2023-08-18 2:29 ` Kemeng Shi
2023-08-18 4:07 ` Theodore Ts'o
2023-08-18 7:09 ` Kemeng Shi
2023-08-18 16:54 ` Theodore Ts'o [this message]
2023-08-22 2:48 ` Kemeng Shi
2023-06-29 12:00 ` [PATCH 12/13] ext4: remove unnecessary check for avoiding multiple update_backups in ext4_flex_group_add Kemeng Shi
2023-08-16 3:47 ` Theodore Ts'o
2023-08-17 3:53 ` Kemeng Shi
2023-08-17 14:11 ` Theodore Ts'o
2023-08-18 3:16 ` Kemeng Shi
2023-08-18 5:00 ` Theodore Ts'o
2023-08-18 8:42 ` Kemeng Shi
2023-08-18 16:00 ` Theodore Ts'o
2023-08-22 2:21 ` Kemeng Shi
2023-06-29 12:00 ` [PATCH 13/13] ext4: remove unnecessary initialization of count2 in set_flexbg_block_bitmap Kemeng Shi
2023-08-16 3:48 ` Theodore Ts'o
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