[PATCH 16/42] xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags()

Dave Chinner
2023-01-18T22:45:19Z

The core of the per-ag iteration is effectively doing a "this ag"
allocation on one AG at a time. Use the same code to implement the
core "this ag" allocation in both xfs_alloc_vextent_this_ag()
and xfs_alloc_vextent_iterate_ags().

This means we only call xfs_alloc_ag_vextent() from one place so we
can easily collapse the call stack in future patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/libxfs/xfs_alloc.c | 50 ++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 39e34a1bfa31..2dec95f35562 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -3244,6 +3244,28 @@ xfs_alloc_vextent_set_fsbno(
/*
* Allocate within a single AG only.
*/
+static int
+__xfs_alloc_vextent_this_ag(
+ struct xfs_alloc_arg *args)
+{
+ struct xfs_mount *mp = args->mp;
+ int error;
+
+ error = xfs_alloc_fix_freelist(args, 0);
+ if (error) {
+ trace_xfs_alloc_vextent_nofix(args);
+ return error;
+ }
+ if (!args->agbp) {
+ /* cannot allocate in this AG at all */
+ trace_xfs_alloc_vextent_noagbp(args);
+ args->agbno = NULLAGBLOCK;
+ return 0;
+ }
+ args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
+ return xfs_alloc_ag_vextent(args);
+}
+
static int
xfs_alloc_vextent_this_ag(
struct xfs_alloc_arg *args,
@@ -3267,21 +3289,9 @@ xfs_alloc_vextent_this_ag(
}

args->pag = xfs_perag_get(mp, args->agno);
- error = xfs_alloc_fix_freelist(args, 0);
- if (error) {
- trace_xfs_alloc_vextent_nofix(args);
- goto out_error;
- }
- if (!args->agbp) {
- trace_xfs_alloc_vextent_noagbp(args);
- args->fsbno = NULLFSBLOCK;
- goto out_error;
- }
- args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
- error = xfs_alloc_ag_vextent(args);
+ error = __xfs_alloc_vextent_this_ag(args);

xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-out_error:
xfs_perag_put(args->pag);
return error;
}
@@ -3319,24 +3329,16 @@ xfs_alloc_vextent_iterate_ags(
args->agno = start_agno;
for (;;) {
args->pag = xfs_perag_get(mp, args->agno);
- error = xfs_alloc_fix_freelist(args, flags);
+ error = __xfs_alloc_vextent_this_ag(args);
if (error) {
- trace_xfs_alloc_vextent_nofix(args);
+ args->agbno = NULLAGBLOCK;
break;
}
- /*
- * If we get a buffer back then the allocation will fly.
- */
- if (args->agbp) {
- error = xfs_alloc_ag_vextent(args);
+ if (args->agbp)
break;
- }

trace_xfs_alloc_vextent_loopfailed(args);

- /*
- * Didn't work, figure out the next iteration.
- */
if (args->agno == start_agno &&
args->otype == XFS_ALLOCTYPE_START_BNO)
args->type = XFS_ALLOCTYPE_THIS_AG;
--
2.39.0