[PATCH 25/42] xfs: move allocation accounting to xfs_alloc_vextent_set_fsbno()

Dave Chinner
2023-01-18T22:45:36Z

Move it from xfs_alloc_ag_vextent() so we can get rid of that layer.
Rename xfs_alloc_vextent_set_fsbno() to xfs_alloc_vextent_finish()
to indicate that it's function is finishing off the allocation that
we've run now that it contains much more functionality.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/libxfs/xfs_alloc.c | 122 ++++++++++++++++++++------------------
1 file changed, 63 insertions(+), 59 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index bfbbb7536310..ad2b91b230f6 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1163,36 +1163,6 @@ xfs_alloc_ag_vextent(
ASSERT(0);
/* NOTREACHED */
}
-
- if (error || args->agbno == NULLAGBLOCK)
- return error;
-
- ASSERT(args->len >= args->minlen);
- ASSERT(args->len <= args->maxlen);
- ASSERT(args->agbno % args->alignment == 0);
-
- /* if not file data, insert new block into the reverse map btree */
- if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) {
- error = xfs_rmap_alloc(args->tp, args->agbp, args->pag,
- args->agbno, args->len, &args->oinfo);
- if (error)
- return error;
- }
-
- if (!args->wasfromfl) {
- error = xfs_alloc_update_counters(args->tp, args->agbp,
- -((long)(args->len)));
- if (error)
- return error;
-
- ASSERT(!xfs_extent_busy_search(args->mp, args->pag,
- args->agbno, args->len));
- }
-
- xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
-
- XFS_STATS_INC(args->mp, xs_allocx);
- XFS_STATS_ADD(args->mp, xs_allocb, args->len);
return error;
}

@@ -3237,18 +3207,21 @@ xfs_alloc_vextent_prepare_ag(
}

/*
- * Post-process allocation results to set the allocated block number correctly
- * for the caller.
+ * Post-process allocation results to account for the allocation if it succeed
+ * and set the allocated block number correctly for the caller.
*
- * XXX: xfs_alloc_vextent() should really be returning ENOSPC for ENOSPC, not
+ * XXX: we should really be returning ENOSPC for ENOSPC, not
* hiding it behind a "successful" NULLFSBLOCK allocation.
*/
-static void
-xfs_alloc_vextent_set_fsbno(
+static int
+xfs_alloc_vextent_finish(
struct xfs_alloc_arg *args,
- xfs_agnumber_t minimum_agno)
+ xfs_agnumber_t minimum_agno,
+ int alloc_error,
+ bool drop_perag)
{
struct xfs_mount *mp = args->mp;
+ int error = 0;

/*
* We can end up here with a locked AGF. If we failed, the caller is
@@ -3271,19 +3244,54 @@ xfs_alloc_vextent_set_fsbno(
args->agno > minimum_agno))
args->tp->t_highest_agno = args->agno;

- /* Allocation failed with ENOSPC if NULLAGBLOCK was returned. */
- if (args->agbno == NULLAGBLOCK) {
+ /*
+ * If the allocation failed with an error or we had an ENOSPC result,
+ * preserve the returned error whilst also marking the allocation result
+ * as "no extent allocated". This ensures that callers that fail to
+ * capture the error will still treat it as a failed allocation.
+ */
+ if (alloc_error || args->agbno == NULLAGBLOCK) {
args->fsbno = NULLFSBLOCK;
- return;
+ error = alloc_error;
+ goto out_drop_perag;
}

args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
-#ifdef DEBUG
+
ASSERT(args->len >= args->minlen);
ASSERT(args->len <= args->maxlen);
ASSERT(args->agbno % args->alignment == 0);
XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno), args->len);
-#endif
+
+ /* if not file data, insert new block into the reverse map btree */
+ if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) {
+ error = xfs_rmap_alloc(args->tp, args->agbp, args->pag,
+ args->agbno, args->len, &args->oinfo);
+ if (error)
+ goto out_drop_perag;
+ }
+
+ if (!args->wasfromfl) {
+ error = xfs_alloc_update_counters(args->tp, args->agbp,
+ -((long)(args->len)));
+ if (error)
+ goto out_drop_perag;
+
+ ASSERT(!xfs_extent_busy_search(mp, args->pag, args->agbno,
+ args->len));
+ }
+
+ xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
+
+ XFS_STATS_INC(mp, xs_allocx);
+ XFS_STATS_ADD(mp, xs_allocb, args->len);
+
+out_drop_perag:
+ if (drop_perag) {
+ xfs_perag_put(args->pag);
+ args->pag = NULL;
+ }
+ return error;
}

/*
@@ -3325,8 +3333,7 @@ xfs_alloc_vextent_this_ag(
if (!error && args->agbp)
error = xfs_alloc_ag_vextent(args);

- xfs_alloc_vextent_set_fsbno(args, minimum_agno);
- return error;
+ return xfs_alloc_vextent_finish(args, minimum_agno, error, false);
}

/*
@@ -3413,10 +3420,10 @@ xfs_alloc_vextent_iterate_ags(
xfs_perag_put(args->pag);
args->pag = NULL;
}
- if (args->pag) {
- xfs_perag_put(args->pag);
- args->pag = NULL;
- }
+ /*
+ * The perag is left referenced in args for the caller to clean
+ * up after they've finished the allocation.
+ */
return error;
}

@@ -3473,8 +3480,7 @@ xfs_alloc_vextent_start_ag(
(mp->m_sb.sb_agcount * rotorstep);
}

- xfs_alloc_vextent_set_fsbno(args, minimum_agno);
- return error;
+ return xfs_alloc_vextent_finish(args, minimum_agno, error, true);
}

/*
@@ -3507,8 +3513,7 @@ xfs_alloc_vextent_first_ag(
args->fsbno = target;
error = xfs_alloc_vextent_iterate_ags(args, minimum_agno,
start_agno, 0);
- xfs_alloc_vextent_set_fsbno(args, minimum_agno);
- return error;
+ return xfs_alloc_vextent_finish(args, minimum_agno, error, true);
}

/*
@@ -3537,6 +3542,7 @@ xfs_alloc_vextent_exact_bno(
args->agno = XFS_FSB_TO_AGNO(mp, target);
if (minimum_agno > args->agno) {
trace_xfs_alloc_vextent_skip_deadlock(args);
+ args->fsbno = NULLFSBLOCK;
return 0;
}

@@ -3548,8 +3554,7 @@ xfs_alloc_vextent_exact_bno(
if (!error && args->agbp)
error = xfs_alloc_ag_vextent(args);

- xfs_alloc_vextent_set_fsbno(args, minimum_agno);
- return 0;
+ return xfs_alloc_vextent_finish(args, minimum_agno, error, false);
}

/*
@@ -3564,8 +3569,8 @@ xfs_alloc_vextent_near_bno(
xfs_rfsblock_t target)
{
struct xfs_mount *mp = args->mp;
- bool need_pag = !args->pag;
xfs_agnumber_t minimum_agno = 0;
+ bool needs_perag = args->pag == NULL;
int error;

if (args->tp->t_highest_agno != NULLAGNUMBER)
@@ -3585,6 +3590,9 @@ xfs_alloc_vextent_near_bno(
return 0;
}

+ if (needs_perag)
+ args->pag = xfs_perag_get(mp, args->agno);
+
args->agbno = XFS_FSB_TO_AGBNO(mp, target);
args->type = XFS_ALLOCTYPE_NEAR_BNO;

@@ -3592,11 +3600,7 @@ xfs_alloc_vextent_near_bno(
if (!error && args->agbp)
error = xfs_alloc_ag_vextent(args);

- xfs_alloc_vextent_set_fsbno(args, minimum_agno);
- if (need_pag)
- xfs_perag_put(args->pag);
-
- return error;
+ return xfs_alloc_vextent_finish(args, minimum_agno, error, needs_perag);
}

/* Ensure that the freelist is at full capacity. */
--
2.39.0