[PATCH v3 05/12] NFSv4/flexfiles: drop the redundant atomic from the busy timer

[Mike Snitzer <snitzer@kernel.org>]

From: Mike Snitzer <snitzer@hammerspace.com>

nfs4_ff_busy_timer::n_ops is an atomic_t, but the stripe lock already
serializes every access to it.  Make it a plain int.

Signed-off-by: Mike Snitzer <snitzer@hammerspace.com>
---
 fs/nfs/flexfilelayout/flexfilelayout.c | 6 ++----
 fs/nfs/flexfilelayout/flexfilelayout.h | 3 ++-
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index dd493ff51d512..81c3d9dd413e5 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -711,9 +711,8 @@ static void
 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 {
 	/* first IO request? */
-	if (atomic_inc_return(&timer->n_ops) == 1) {
+	if (++timer->n_ops == 1)
 		timer->start_time = now;
-	}
 }
 
 static ktime_t
@@ -721,8 +720,7 @@ nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 {
 	ktime_t start;
 
-	if (atomic_dec_return(&timer->n_ops) < 0)
-		WARN_ON_ONCE(1);
+	WARN_ON_ONCE(--timer->n_ops < 0);
 
 	start = timer->start_time;
 	timer->start_time = now;
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h
index 90a0ed1dd822e..483d730659713 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.h
+++ b/fs/nfs/flexfilelayout/flexfilelayout.h
@@ -64,9 +64,10 @@ struct nfs4_ff_io_stat {
 	ktime_t				aggregate_completion_time;
 };
 
+/* Both members are protected by the enclosing stripe's lock */
 struct nfs4_ff_busy_timer {
 	ktime_t start_time;
-	atomic_t n_ops;
+	int n_ops;
 };
 
 struct nfs4_ff_layoutstat {
-- 
2.52.0