[PATCH, post-03/20 1/1] xfs: hook up inodegc to CPU dead notification

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

So we don't leave queued inodes on a CPU we won't ever flush.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 fs/xfs/xfs_icache.c | 36 ++++++++++++++++++++++++++++++++++++
 fs/xfs/xfs_icache.h |  1 +
 fs/xfs/xfs_super.c  |  2 +-
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index f772f2a67a8b..9e2c95903c68 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1966,6 +1966,42 @@ xfs_inodegc_start(
 	}
 }
 
+/*
+ * Fold the dead CPU inodegc queue into the current CPUs queue.
+ */
+void
+xfs_inodegc_cpu_dead(
+	struct xfs_mount	*mp,
+	int			dead_cpu)
+{
+	struct xfs_inodegc	*dead_gc, *gc;
+	struct llist_node	*first, *last;
+	int			count = 0;
+
+	dead_gc = per_cpu_ptr(mp->m_inodegc, dead_cpu);
+	cancel_work_sync(&dead_gc->work);
+
+	if (llist_empty(&dead_gc->list))
+		return;
+
+	first = dead_gc->list.first;
+	last = first;
+	while (last->next) {
+		last = last->next;
+		count++;
+	}
+	dead_gc->list.first = NULL;
+	dead_gc->items = 0;
+
+	/* Add pending work to current CPU */
+	gc = get_cpu_ptr(mp->m_inodegc);
+	llist_add_batch(first, last, &gc->list);
+	count += READ_ONCE(gc->items);
+	WRITE_ONCE(gc->items, count);
+	put_cpu_ptr(gc);
+	queue_work(mp->m_inodegc_wq, &gc->work);
+}
+
 #ifdef CONFIG_XFS_RT
 static inline bool
 xfs_inodegc_want_queue_rt_file(
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index bdf2a8d3fdd5..853d5bfc0cfb 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -79,5 +79,6 @@ void xfs_inodegc_worker(struct work_struct *work);
 void xfs_inodegc_flush(struct xfs_mount *mp);
 void xfs_inodegc_stop(struct xfs_mount *mp);
 void xfs_inodegc_start(struct xfs_mount *mp);
+void xfs_inodegc_cpu_dead(struct xfs_mount *mp, int cpu);
 
 #endif
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c251679e8514..f579ec49eb7a 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -2187,7 +2187,7 @@ xfs_cpu_dead(
 	spin_lock(&xfs_mount_list_lock);
 	list_for_each_entry_safe(mp, n, &xfs_mount_list, m_mount_list) {
 		spin_unlock(&xfs_mount_list_lock);
-		/* xfs_subsys_dead(mp, cpu); */
+		xfs_inodegc_cpu_dead(mp, cpu);
 		spin_lock(&xfs_mount_list_lock);
 	}
 	spin_unlock(&xfs_mount_list_lock);