From dd2922dcfaa3296846265e113309e5f7f138839f Mon Sep 17 00:00:00 2001 From: Zeng Heng Date: Tue, 3 Jun 2025 20:58:28 +0800 Subject: [PATCH] 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 Signed-off-by: Thomas Gleixner Reviewed-by: Reinette Chatre 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 cc37f58b47dd..1beb124e25f6 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. -- 2.25.1