[PATCH v6 08/10] fs/resctrl: Call architecture hooks for every mount/unmount

Tony Luck
2026-04-29T18:49:23Z

Architecture code for AET needs to acquire INTEL_PMT_TELEMETRY module
references on mount and release them on unmount.

Add hooks for every mount/unmount of the resctrl file system so that
architecture code can allocate on mount and free on unmount.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/resctrl.h | 7 +++++--
fs/resctrl/rdtgroup.c | 9 +++++++--
2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 9534d42e0c57..e8a87c3664db 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -552,12 +552,15 @@ void resctrl_online_cpu(unsigned int cpu);
void resctrl_offline_cpu(unsigned int cpu);

/*
- * Architecture hook called at beginning of first file system mount attempt.
+ * Architecture hook called before attempting to mount the file system.
* No locks are held.
*/
void resctrl_arch_pre_mount(void);

-/* Called to report unmount. */
+/*
+ * Architecture hook called when mount fails, or on unmount.
+ * No locks are held.
+ */
void resctrl_arch_unmount(void);

/**
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 2e31ff753114..134ad69de194 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -18,7 +18,6 @@
#include <linux/fs_parser.h>
#include <linux/sysfs.h>
#include <linux/kernfs.h>
-#include <linux/once.h>
#include <linux/resctrl.h>
#include <linux/seq_buf.h>
#include <linux/seq_file.h>
@@ -2790,7 +2789,7 @@ static int rdt_get_tree(struct fs_context *fc)
struct rdt_resource *r;
int ret;

- DO_ONCE_SLEEPABLE(resctrl_arch_pre_mount);
+ resctrl_arch_pre_mount();

cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
@@ -2899,6 +2898,10 @@ static int rdt_get_tree(struct fs_context *fc)
rdt_last_cmd_clear();
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
+
+ if (ret)
+ resctrl_arch_unmount();
+
return ret;
}

@@ -3191,6 +3194,8 @@ static void rdt_kill_sb(struct super_block *sb)
kernfs_kill_sb(sb);
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
+
+ resctrl_arch_unmount();
}

static struct file_system_type rdt_fs_type = {
--
2.53.0