The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: dd2922dcfaa3296846265e113309e5f7f138839f
Gitweb: https://git.kernel.org/tip/dd2922dcfaa3296846265e113309e5f7f138839f
Author: Zeng Heng <zengheng4@huawei.com>
AuthorDate: Tue, 03 Jun 2025 20:58:28 +08:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 04 Jun 2025 20:32:55 +02:00
fs/resctrl: Restore the rdt_last_cmd_clear() calls after acquiring rdtgroup_mutex
A lockdep fix removed two rdt_last_cmd_clear() calls that were used to
clear the last_cmd_status buffer but called without holding the required
rdtgroup_mutex.
The impacted resctrl commands are writing to the cpus or cpus_list files
and creating a new monitor or control group. With stale data in the
last_cmd_status buffer the impacted resctrl commands report the stale error
on success, or append its own failure message to the stale error on
failure.
Consequently, restore the rdt_last_cmd_clear() calls after acquiring
rdtgroup_mutex.
Fixes: c8eafe149530 ("x86/resctrl: Fix potential lockdep warning")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/all/20250603125828.1590067-1-zengheng4@huawei.com
---
fs/resctrl/rdtgroup.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index cc37f58..1beb124 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -536,6 +536,8 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
goto unlock;
}
+ rdt_last_cmd_clear();
+
if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
ret = -EINVAL;
@@ -3472,6 +3474,8 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
goto out_unlock;
}
+ rdt_last_cmd_clear();
+
/*
* Check that the parent directory for a monitor group is a "mon_groups"
* directory.