Re: [PATCH 23/42] xfs: introduce xfs_alloc_vextent_exact_bno()

Darrick J. Wong
2023-02-01T23:00:54Z

On Thu, Jan 19, 2023 at 09:44:46AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Two of the callers to xfs_alloc_vextent_this_ag() actually want
> exact block number allocation, not anywhere-in-ag allocation. Split
> this out from _this_ag() as a first class citizen so no external
> extent allocation code needs to care about args->type anymore.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---
> fs/xfs/libxfs/xfs_ag.c | 6 ++--
> fs/xfs/libxfs/xfs_alloc.c | 65 ++++++++++++++++++++++++++++++++------
> fs/xfs/libxfs/xfs_alloc.h | 13 ++++++--
> fs/xfs/libxfs/xfs_bmap.c | 6 ++--
> fs/xfs/libxfs/xfs_ialloc.c | 6 ++--
> fs/xfs/scrub/repair.c | 4 +--
> 6 files changed, 73 insertions(+), 27 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c
> index 053d77a283f7..86696a1c6891 100644
> --- a/fs/xfs/libxfs/xfs_ag.c
> +++ b/fs/xfs/libxfs/xfs_ag.c
> @@ -888,7 +888,6 @@ xfs_ag_shrink_space(
> .tp = *tpp,
> .mp = mp,
> .pag = pag,
> - .type = XFS_ALLOCTYPE_THIS_BNO,
> .minlen = delta,
> .maxlen = delta,
> .oinfo = XFS_RMAP_OINFO_SKIP_UPDATE,
> @@ -920,8 +919,6 @@ xfs_ag_shrink_space(
> if (delta >= aglen)
> return -EINVAL;
>
> - args.fsbno = XFS_AGB_TO_FSB(mp, pag->pag_agno, aglen - delta);
> -
> /*
> * Make sure that the last inode cluster cannot overlap with the new
> * end of the AG, even if it's sparse.
> @@ -939,7 +936,8 @@ xfs_ag_shrink_space(
> return error;
>
> /* internal log shouldn't also show up in the free space btrees */
> - error = xfs_alloc_vextent_this_ag(&args);
> + error = xfs_alloc_vextent_exact_bno(&args,
> + XFS_AGB_TO_FSB(mp, pag->pag_agno, aglen - delta));
> if (!error && args.agbno == NULLAGBLOCK)
> error = -ENOSPC;
>
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index 485a73eab9d9..b810a94aad70 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -3272,28 +3272,34 @@ xfs_alloc_vextent_set_fsbno(
> */
> int
> xfs_alloc_vextent_this_ag(
> - struct xfs_alloc_arg *args)
> + struct xfs_alloc_arg *args,
> + xfs_agnumber_t agno)
> {
> struct xfs_mount *mp = args->mp;
> xfs_agnumber_t minimum_agno = 0;
> + xfs_rfsblock_t target = XFS_AGB_TO_FSB(mp, agno, 0);

Same xfs_rfsblock_t vs. xfs_fsblock_t comment here too.

These conversions look like a good improvement though -- it's very
helpful that we can now look at an xfs_alloc_vextent_* call and know
exactly which behavior we're getting.

--D

> int error;
>
> if (args->tp->t_highest_agno != NULLAGNUMBER)
> minimum_agno = args->tp->t_highest_agno;
>
> - error = xfs_alloc_vextent_check_args(args, args->fsbno);
> + if (minimum_agno > agno) {
> + trace_xfs_alloc_vextent_skip_deadlock(args);
> + args->fsbno = NULLFSBLOCK;
> + return 0;
> + }
> +
> + error = xfs_alloc_vextent_check_args(args, target);
> if (error) {
> if (error == -ENOSPC)
> return 0;
> return error;
> }
>
> - args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
> - if (minimum_agno > args->agno) {
> - trace_xfs_alloc_vextent_skip_deadlock(args);
> - args->fsbno = NULLFSBLOCK;
> - return 0;
> - }
> + args->agno = agno;
> + args->agbno = 0;
> + args->fsbno = target;
> + args->type = XFS_ALLOCTYPE_THIS_AG;
>
> error = xfs_alloc_ag_vextent(args);
> xfs_alloc_vextent_set_fsbno(args, minimum_agno);
> @@ -3450,7 +3456,7 @@ xfs_alloc_vextent_start_ag(
> * pass, so will not recurse into AGs lower than indicated by fsbno.
> */
> int
> - xfs_alloc_vextent_first_ag(
> +xfs_alloc_vextent_first_ag(
> struct xfs_alloc_arg *args,
> xfs_rfsblock_t target)
> {
> @@ -3472,12 +3478,51 @@ int
> start_agno = max(minimum_agno, XFS_FSB_TO_AGNO(mp, target));
> args->type = XFS_ALLOCTYPE_THIS_AG;
> args->fsbno = target;
> - error = xfs_alloc_vextent_iterate_ags(args, minimum_agno,
> + error = xfs_alloc_vextent_iterate_ags(args, minimum_agno,
> start_agno, 0);
> xfs_alloc_vextent_set_fsbno(args, minimum_agno);
> return error;
> }
>
> +/*
> + * Allocate within a single AG only.
> + */
> +int
> +xfs_alloc_vextent_exact_bno(
> + struct xfs_alloc_arg *args,
> + xfs_rfsblock_t target)
> +{
> + struct xfs_mount *mp = args->mp;
> + xfs_agnumber_t minimum_agno = 0;
> + int error;
> +
> + if (args->tp->t_highest_agno != NULLAGNUMBER)
> + minimum_agno = args->tp->t_highest_agno;
> +
> + error = xfs_alloc_vextent_check_args(args, target);
> + if (error) {
> + if (error == -ENOSPC)
> + return 0;
> + return error;
> + }
> +
> + args->agno = XFS_FSB_TO_AGNO(mp, target);
> + if (minimum_agno > args->agno) {
> + trace_xfs_alloc_vextent_skip_deadlock(args);
> + return 0;
> + }
> +
> + args->agbno = XFS_FSB_TO_AGBNO(mp, target);
> + args->fsbno = target;
> + args->type = XFS_ALLOCTYPE_THIS_BNO;
> + error = xfs_alloc_ag_vextent(args);
> + if (error)
> + return error;
> +
> + xfs_alloc_vextent_set_fsbno(args, minimum_agno);
> + return 0;
> +}
> +
> /*
> * Allocate an extent as close to the target as possible. If there are not
> * viable candidates in the AG, then fail the allocation.
> diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
> index f38a2f8e20fb..106b4deb1110 100644
> --- a/fs/xfs/libxfs/xfs_alloc.h
> +++ b/fs/xfs/libxfs/xfs_alloc.h
> @@ -114,10 +114,10 @@ xfs_alloc_log_agf(
> uint32_t fields);/* mask of fields to be logged (XFS_AGF_...) */
>
> /*
> - * Allocate an extent in the specific AG defined by args->fsbno. If there is no
> - * space in that AG, then the allocation will fail.
> + * Allocate an extent anywhere in the specific AG given. If there is no
> + * space matching the requirements in that AG, then the allocation will fail.
> */
> -int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args);
> +int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args, xfs_agnumber_t agno);
>
> /*
> * Allocate an extent as close to the target as possible. If there are not
> @@ -126,6 +126,13 @@ int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args);
> int xfs_alloc_vextent_near_bno(struct xfs_alloc_arg *args,
> xfs_rfsblock_t target);
>
> +/*
> + * Allocate an extent exactly at the target given. If this is not possible
> + * then the allocation fails.
> + */
> +int xfs_alloc_vextent_exact_bno(struct xfs_alloc_arg *args,
> + xfs_rfsblock_t target);
> +
> /*
> * Best effort full filesystem allocation scan.
> *
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 4446b035eed5..c9902df16e25 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -3514,7 +3514,6 @@ xfs_bmap_btalloc_at_eof(
> xfs_extlen_t nextminlen = 0;
>
> atype = args->type;
> - args->type = XFS_ALLOCTYPE_THIS_BNO;
> args->alignment = 1;
>
> /*
> @@ -3532,8 +3531,8 @@ xfs_bmap_btalloc_at_eof(
> else
> args->minalignslop = 0;
>
> - args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, args->fsbno));
> - error = xfs_alloc_vextent_this_ag(args);
> + args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, ap->blkno));
> + error = xfs_alloc_vextent_exact_bno(args, ap->blkno);
> xfs_perag_put(args->pag);
> if (error)
> return error;
> @@ -3546,7 +3545,6 @@ xfs_bmap_btalloc_at_eof(
> */
> args->pag = NULL;
> args->type = atype;
> - args->fsbno = ap->blkno;
> args->alignment = stripe_align;
> args->minlen = nextminlen;
> args->minalignslop = 0;
> diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
> index daa6f7055bba..d2525f0cc6cd 100644
> --- a/fs/xfs/libxfs/xfs_ialloc.c
> +++ b/fs/xfs/libxfs/xfs_ialloc.c
> @@ -662,8 +662,6 @@ xfs_ialloc_ag_alloc(
> goto sparse_alloc;
> if (likely(newino != NULLAGINO &&
> (args.agbno < be32_to_cpu(agi->agi_length)))) {
> - args.fsbno = XFS_AGB_TO_FSB(args.mp, pag->pag_agno, args.agbno);
> - args.type = XFS_ALLOCTYPE_THIS_BNO;
> args.prod = 1;
>
> /*
> @@ -684,7 +682,9 @@ xfs_ialloc_ag_alloc(
>
> /* Allow space for the inode btree to split. */
> args.minleft = igeo->inobt_maxlevels;
> - error = xfs_alloc_vextent_this_ag(&args);
> + error = xfs_alloc_vextent_exact_bno(&args,
> + XFS_AGB_TO_FSB(args.mp, pag->pag_agno,
> + args.agbno));
> if (error)
> return error;
>
> diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> index 5f4b50aac4bb..1b71174ec0d6 100644
> --- a/fs/xfs/scrub/repair.c
> +++ b/fs/xfs/scrub/repair.c
> @@ -328,14 +328,12 @@ xrep_alloc_ag_block(
> args.mp = sc->mp;
> args.pag = sc->sa.pag;
> args.oinfo = *oinfo;
> - args.fsbno = XFS_AGB_TO_FSB(args.mp, sc->sa.pag->pag_agno, 0);
> args.minlen = 1;
> args.maxlen = 1;
> args.prod = 1;
> - args.type = XFS_ALLOCTYPE_THIS_AG;
> args.resv = resv;
>
> - error = xfs_alloc_vextent_this_ag(&args);
> + error = xfs_alloc_vextent_this_ag(&args, sc->sa.pag->pag_agno);
> if (error)
> return error;
> if (args.fsbno == NULLFSBLOCK)
> --
> 2.39.0
>