From 2a154b84847d9895b76bfb41a6e30e0a627ee62c Mon Sep 17 00:00:00 2001 From: MigeljanImeri <78048439+MigeljanImeri@users.noreply.github.com> Date: Tue, 7 Nov 2023 10:06:14 -0700 Subject: [PATCH] Fix accounting error for pending sync IO ops in zpool iostat Currently vdev_queue_class_length is responsible for checking how long the queue length is, however, it doesn't check the length when a list is used, rather it just returns whether it is empty or not. To fix this I added a counter variable to vdev_queue_class to keep track of the sync IO ops, and changed vdev_queue_class_length to reference this variable instead. Reviewed-by: Brian Behlendorf Reviewed-by: Alexander Motin Signed-off-by: MigeljanImeri Closes #15478 --- include/sys/vdev_impl.h | 5 ++++- module/zfs/vdev_queue.c | 7 +++++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/include/sys/vdev_impl.h b/include/sys/vdev_impl.h index ad9dc3aefd8e..3f2312c23438 100644 --- a/include/sys/vdev_impl.h +++ b/include/sys/vdev_impl.h @@ -131,7 +131,10 @@ typedef const struct vdev_ops { * Virtual device properties */ typedef union vdev_queue_class { - list_t vqc_list; + struct { + ulong_t vqc_list_numnodes; + list_t vqc_list; + }; avl_tree_t vqc_tree; } vdev_queue_class_t; diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c index 08d918467d03..092b3f375be0 100644 --- a/module/zfs/vdev_queue.c +++ b/module/zfs/vdev_queue.c @@ -273,8 +273,10 @@ vdev_queue_class_add(vdev_queue_t *vq, zio_t *zio) { zio_priority_t p = zio->io_priority; vq->vq_cqueued |= 1U << p; - if (vdev_queue_class_fifo(p)) + if (vdev_queue_class_fifo(p)) { list_insert_tail(&vq->vq_class[p].vqc_list, zio); + vq->vq_class[p].vqc_list_numnodes++; + } else avl_add(&vq->vq_class[p].vqc_tree, zio); } @@ -288,6 +290,7 @@ vdev_queue_class_remove(vdev_queue_t *vq, zio_t *zio) list_t *list = &vq->vq_class[p].vqc_list; list_remove(list, zio); empty = list_is_empty(list); + vq->vq_class[p].vqc_list_numnodes--; } else { avl_tree_t *tree = &vq->vq_class[p].vqc_tree; avl_remove(tree, zio); @@ -1069,7 +1072,7 @@ vdev_queue_class_length(vdev_t *vd, zio_priority_t p) { vdev_queue_t *vq = &vd->vdev_queue; if (vdev_queue_class_fifo(p)) - return (list_is_empty(&vq->vq_class[p].vqc_list) == 0); + return (vq->vq_class[p].vqc_list_numnodes); else return (avl_numnodes(&vq->vq_class[p].vqc_tree)); }