From 4367312760612cb755acfc218ffeda8eb35ce509 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markjdb@gmail.com>
Date: Wed, 10 Jul 2024 16:27:44 -0500
Subject: [PATCH] zvol: Fix suspend lock leaks (#16270)

In several functions, we use a flag variable to track whether
zv_suspend_lock is held.  This flag was not getting reset in a
particular case where we need to retry the underlying operation,
resulting in a lock leak.  Make sure to update the flag where necessary.

Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
---
 module/os/freebsd/zfs/zvol_os.c | 2 ++
 module/os/linux/zfs/zvol_os.c   | 1 +
 2 files changed, 3 insertions(+)

diff --git a/module/os/freebsd/zfs/zvol_os.c b/module/os/freebsd/zfs/zvol_os.c
index 712ff1b83..38e9debbe 100644
--- a/module/os/freebsd/zfs/zvol_os.c
+++ b/module/os/freebsd/zfs/zvol_os.c
@@ -292,6 +292,7 @@ retry:
 			if (!mutex_tryenter(&spa_namespace_lock)) {
 				mutex_exit(&zv->zv_state_lock);
 				rw_exit(&zv->zv_suspend_lock);
+				drop_suspend = B_FALSE;
 				kern_yield(PRI_USER);
 				goto retry;
 			} else {
@@ -983,6 +984,7 @@ retry:
 			if (!mutex_tryenter(&spa_namespace_lock)) {
 				mutex_exit(&zv->zv_state_lock);
 				rw_exit(&zv->zv_suspend_lock);
+				drop_suspend = B_FALSE;
 				kern_yield(PRI_USER);
 				goto retry;
 			} else {
diff --git a/module/os/linux/zfs/zvol_os.c b/module/os/linux/zfs/zvol_os.c
index acb42c3b4..1d5d54b80 100644
--- a/module/os/linux/zfs/zvol_os.c
+++ b/module/os/linux/zfs/zvol_os.c
@@ -791,6 +791,7 @@ retry:
 			if (!mutex_tryenter(&spa_namespace_lock)) {
 				mutex_exit(&zv->zv_state_lock);
 				rw_exit(&zv->zv_suspend_lock);
+				drop_suspend = B_FALSE;
 
 #ifdef HAVE_BLKDEV_GET_ERESTARTSYS
 				schedule();