While the resctl code is a bit confusing, I can't find anything protected
by rdtgroup_mutex or the CPU hotplug lock in generic_shutdown_super or
kernfs_free_sb. Drop the locks at the end of rdt_shutdown_sb to avoid
holding locks over method calls and VFS code which itself already has a
rather complicated locking hierarchy.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 8db767fd80df6b..e87de519493021 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2793,11 +2793,6 @@ static void rdt_shutdown_sb(struct super_block *sb)
static_branch_disable_cpuslocked(&rdt_mon_enable_key);
static_branch_disable_cpuslocked(&rdt_enable_key);
kernfs_shutdown_sb(sb);
-}
-
-static void rdt_free_sb(struct super_block *sb)
-{
- kernfs_free_sb(sb);
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
}
@@ -2807,7 +2802,7 @@ static struct file_system_type rdt_fs_type = {
.init_fs_context = rdt_init_fs_context,
.parameters = rdt_fs_parameters,
.shutdown_sb = rdt_shutdown_sb,
- .free_sb = rdt_free_sb,
+ .free_sb = kernfs_free_sb,
};
static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
--
2.39.2
