On Mon, Feb 11, 2019 at 01:54:26PM +0100, Christoph Hellwig wrote:
> Now that we properly handle the race with truncate in the delalloc
> allocator there is no need to short cut this exceptional case earlier
> on.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/xfs_aops.c | 20 --------------------
> 1 file changed, 20 deletions(-)
>
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 403df647c0e4..6a8937a833ad 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -426,26 +426,6 @@ xfs_map_blocks(
> xfs_iunlock(ip, XFS_ILOCK_SHARED);
>
> wpc->fork = XFS_COW_FORK;
> -
> - /*
> - * Truncate can race with writeback since writeback doesn't
> - * take the iolock and truncate decreases the file size before
> - * it starts truncating the pages between new_size and old_size.
> - * Therefore, we can end up in the situation where writeback
> - * gets a CoW fork mapping but the truncate makes the mapping
> - * invalid and we end up in here trying to get a new mapping.
> - * bail out here so that we simply never get a valid mapping
> - * and so we drop the write altogether. The page truncation
> - * will kill the contents anyway.
> - */
> - if (offset > i_size_read(inode)) {
> - wpc->imap.br_blockcount = end_fsb - offset_fsb;
> - wpc->imap.br_startoff = offset_fsb;
> - wpc->imap.br_startblock = HOLESTARTBLOCK;
> - wpc->imap.br_state = XFS_EXT_NORM;
> - return 0;
> - }
> -
> goto allocate_blocks;
> }
>
> --
> 2.20.1
>
