On Sun, Jan 31, 2021 at 06:06:34PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> If a fs modification (creation, file write, reflink, etc.) is unable to
> reserve enough space to handle the modification, try clearing whatever
> space the filesystem might have been hanging onto in the hopes of
> speeding up the filesystem. The flushing behavior will become
> particularly important when we add deferred inode inactivation because
> that will increase the amount of space that isn't actively tied to user
> data.
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/xfs_trans.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
>
> diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
> index 3203841ab19b..973354647298 100644
> --- a/fs/xfs/xfs_trans.c
> +++ b/fs/xfs/xfs_trans.c
> @@ -289,6 +289,17 @@ xfs_trans_alloc(
> tp->t_firstblock = NULLFSBLOCK;
>
> error = xfs_trans_reserve(tp, resp, blocks, rtextents);
> + if (error == -ENOSPC) {
> + /*
> + * We weren't able to reserve enough space for the transaction.
> + * Flush the other speculative space allocations to free space.
> + * Do not perform a synchronous scan because callers can hold
> + * other locks.
> + */
> + error = xfs_blockgc_free_space(mp, NULL);
> + if (!error)
> + error = xfs_trans_reserve(tp, resp, blocks, rtextents);
> + }
> if (error) {
> xfs_trans_cancel(tp);
> return error;
>
