On Fri, Mar 05, 2021 at 10:57:00AM +0800, Gao Xiang wrote:
> Move out related logic for initializing new added AGs to a new helper
> in preparation for shrinking. No logic changes.
>
> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx>
> ---
> fs/xfs/xfs_fsops.c | 107 +++++++++++++++++++++++++++------------------
> 1 file changed, 64 insertions(+), 43 deletions(-)
>
> diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> index 9f9ba8bd0213..fc9e799b2ae3 100644
> --- a/fs/xfs/xfs_fsops.c
> +++ b/fs/xfs/xfs_fsops.c
> @@ -20,6 +20,64 @@
> #include "xfs_ag.h"
> #include "xfs_ag_resv.h"
>
> +/*
> + * Write new AG headers to disk. Non-transactional, but need to be
> + * written and completed prior to the growfs transaction being logged.
> + * To do this, we use a delayed write buffer list and wait for
> + * submission and IO completion of the list as a whole. This allows the
> + * IO subsystem to merge all the AG headers in a single AG into a single
> + * IO and hide most of the latency of the IO from us.
> + *
> + * This also means that if we get an error whilst building the buffer
> + * list to write, we can cancel the entire list without having written
> + * anything.
> + */
> +static int
> +xfs_resizefs_init_new_ags(
> + struct xfs_trans *tp,
> + struct aghdr_init_data *id,
> + xfs_agnumber_t oagcount,
> + xfs_agnumber_t nagcount,
> + xfs_rfsblock_t delta,
> + bool *lastag_resetagres)
Nit: I'd just call this lastag_extended or something that otherwise
indicates what this function reports (as opposed to trying to tell the
caller what to do).
> +{
> + struct xfs_mount *mp = tp->t_mountp;
> + xfs_rfsblock_t nb = mp->m_sb.sb_dblocks + delta;
> + int error;
> +
> + *lastag_resetagres = false;
> +
> + INIT_LIST_HEAD(&id->buffer_list);
> + for (id->agno = nagcount - 1;
> + id->agno >= oagcount;
> + id->agno--, delta -= id->agsize) {
> +
> + if (id->agno == nagcount - 1)
> + id->agsize = nb - (id->agno *
> + (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
> + else
> + id->agsize = mp->m_sb.sb_agblocks;
> +
> + error = xfs_ag_init_headers(mp, id);
> + if (error) {
> + xfs_buf_delwri_cancel(&id->buffer_list);
> + return error;
> + }
> + }
> +
> + error = xfs_buf_delwri_submit(&id->buffer_list);
> + if (error)
> + return error;
> +
> + xfs_trans_agblocks_delta(tp, id->nfree);
> +
> + if (delta) {
> + *lastag_resetagres = true;
> + error = xfs_ag_extend_space(mp, tp, id, delta);
> + }
> + return error;
> +}
> +
> /*
> * growfs operations
> */
...
> @@ -123,9 +145,8 @@ xfs_growfs_data_private(
> */
> if (nagcount > oagcount)
> xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
> - if (nb > mp->m_sb.sb_dblocks)
> - xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
> - nb - mp->m_sb.sb_dblocks);
> + if (delta > 0)
> + xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta);
Hm.. isn't delta still unsigned as of this patch?
Brian
> if (id.nfree)
> xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
>
> @@ -152,7 +173,7 @@ xfs_growfs_data_private(
> * If we expanded the last AG, free the per-AG reservation
> * so we can reinitialize it with the new size.
> */
> - if (delta) {
> + if (lastag_resetagres) {
> struct xfs_perag *pag;
>
> pag = xfs_perag_get(mp, id.agno);
> --
> 2.27.0
>
