On Fri 07-11-25 22:42:32, libaokun@huaweicloud.com wrote:
> From: Baokun Li <libaokun1@huawei.com>
>
> ext4_calculate_overhead() used a single page for its bitmap buffer, which
> worked fine when PAGE_SIZE >= block size. However, with block size greater
> than page size (BS > PS) support, the bitmap can exceed a single page.
>
> To address this, we now use kvmalloc() to allocate memory of the filesystem
> block size, to properly support BS > PS.
>
> Suggested-by: Jan Kara <jack@suse.cz>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>
> Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/ext4/super.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index a6314a3de51d..0d32370a459a 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4189,7 +4189,7 @@ int ext4_calculate_overhead(struct super_block *sb)
> unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
> ext4_group_t i, ngroups = ext4_get_groups_count(sb);
> ext4_fsblk_t overhead = 0;
> - char *buf = (char *) get_zeroed_page(GFP_NOFS);
> + char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO);
>
> if (!buf)
> return -ENOMEM;
> @@ -4214,7 +4214,7 @@ int ext4_calculate_overhead(struct super_block *sb)
> blks = count_overhead(sb, i, buf);
> overhead += blks;
> if (blks)
> - memset(buf, 0, PAGE_SIZE);
> + memset(buf, 0, sb->s_blocksize);
> cond_resched();
> }
>
> @@ -4237,7 +4237,7 @@ int ext4_calculate_overhead(struct super_block *sb)
> }
> sbi->s_overhead = overhead;
> smp_wmb();
> - free_page((unsigned long) buf);
> + kvfree(buf);
> return 0;
> }
>
> --
> 2.46.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR