Re: [PATCH v1 3/4] ntfs: wait for the bitmap scan before MFT bitmap extension

[liubaolin <liubaolin12138@163.com>]

在 2026/9/24 09:45, Xuewen Wang 写道:
> If MFT bitmap extension fails before the initial $Bitmap scan completes,
> rollback calls ntfs_bitmap_clear_bit(), which holds a folio lock while
> ntfs_set_lcn_empty_bits() waits for the scan. The scanner deadlocks if it
> still needs that folio.
> 
> Wait for the initial scan before taking the runlist or bitmap folio locks
> and attempting allocation.
> 
> Fixes: 11ccc9107dc4 ("ntfs: update runlist handling and cluster allocator")
> Reviewed-by: Baolin Liu <liubaolin@kylinos.cn>
> Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn>
> ---
>   fs/ntfs/mft.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
> index 12666668a80e..489a5935202c 100644
> --- a/fs/ntfs/mft.c
> +++ b/fs/ntfs/mft.c
> @@ -1352,6 +1352,10 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(struct ntfs_volume *vol)
>   	size_t new_rl_count;
>   
>   	ntfs_debug("Extending mft bitmap allocation.");
> +	/* The initial bitmap scan must finish before we lock or change a folio. */
> +	if (!NVolFreeClusterKnown(vol))
> +		wait_event(vol->free_waitq, NVolFreeClusterKnown(vol));
> +
>   	mft_ni = NTFS_I(vol->mft_ino);
>   	mftbmp_ni = NTFS_I(vol->mftbmp_ino);
>   	/*

Looks good to me.

Reviewed-by: Baolin Liu <liubaolin@kylinos.cn>