On Tue, Sep 29, 2020 at 10:43:44AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> When xfs_defer_capture extracts the deferred ops and transaction state
> from a transaction, it should record the transaction reservation type
> from the old transaction so that when we continue the dfops chain, we
> still use the same reservation parameters.
>
> Doing this means that the log item recovery functions get to determine
> the transaction reservation instead of abusing tr_itruncate in yet
> another part of xfs.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
Much nicer, and FWIW this is pretty much the approach I was wondering
about wrt to the block reservation in the previous patch..
> fs/xfs/libxfs/xfs_defer.c | 9 +++++++++
> fs/xfs/libxfs/xfs_defer.h | 1 +
> fs/xfs/xfs_log_recover.c | 4 ++--
> 3 files changed, 12 insertions(+), 2 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
> index 0cceebb390c4..4caaf5527403 100644
> --- a/fs/xfs/libxfs/xfs_defer.c
> +++ b/fs/xfs/libxfs/xfs_defer.c
> @@ -579,6 +579,15 @@ xfs_defer_ops_capture(
> dfc->dfc_blkres = tp->t_blk_res - tp->t_blk_res_used;
> tp->t_blk_res = tp->t_blk_res_used;
>
> + /*
> + * Preserve the transaction reservation type. The logcount is
> + * hardwired to 1 to so that we can make forward progress in recovery
> + * no matter how full the log might be, at a cost of more regrants.
> + */
> + dfc->dfc_tres.tr_logres = tp->t_log_res;
> + dfc->dfc_tres.tr_logcount = 1;
> + dfc->dfc_tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
Any real need to allocate these last two fields in every captured chain
when they're basically hardcoded? If not, it might be a bit more
efficient to put an xfs_trans_res on the stack in
xlog_finish_defer_ops() and just save the logres value here.
Brian
> +
> return dfc;
> }
>
> diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
> index b1c7b761afd5..c447c79bbe74 100644
> --- a/fs/xfs/libxfs/xfs_defer.h
> +++ b/fs/xfs/libxfs/xfs_defer.h
> @@ -76,6 +76,7 @@ struct xfs_defer_capture {
> struct list_head dfc_dfops;
> unsigned int dfc_tpflags;
> unsigned int dfc_blkres;
> + struct xfs_trans_res dfc_tres;
> };
>
> /*
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index b06c9881a13d..46e750279634 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -2442,8 +2442,8 @@ xlog_finish_defer_ops(
> int error = 0;
>
> list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
> - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0,
> - 0, XFS_TRANS_RESERVE, &tp);
> + error = xfs_trans_alloc(mp, &dfc->dfc_tres, 0, 0,
> + XFS_TRANS_RESERVE, &tp);
> if (error)
> return error;
>
>
