Re: [PATCH] f2fs: fix to adjust appropirate defragment pg_end

[Chao Yu]

On 2024/3/22 14:03, Zhiguo Niu wrote:
> A length that exceeds the real size of the inode may be
> specified from user, although these out-of-range areas
> are not mapped, but they still need to be check in
> while loop, which is unnecessary.
>
> Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> ---
>   fs/f2fs/file.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 128e53d..0e7eac6 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2609,7 +2609,9 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
>   	int err;
>   
>   	pg_start = range->start >> PAGE_SHIFT;
> -	pg_end = (range->start + range->len) >> PAGE_SHIFT;
> +	pg_end = min_t(pgoff_t,
> +			(range->start + range->len) >> PAGE_SHIFT,
> +			DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE));

I guess we may check i_size w/ inode lock, it can avoid racing w/ append write
or truncate.

Thanks,

>   
>   	f2fs_balance_fs(sbi, true);
>