diff options
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/rdtgroup.c | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 29f76ad21f1c..1e48c61db2aa 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -3078,6 +3078,22 @@ static void rmdir_all_sub(void) kernfs_remove(kn_mondata); } +static void resctrl_fs_teardown(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + + /* Cleared by rdtgroup_destroy_root() */ + if (!rdtgroup_default.kn) + return; + + rmdir_all_sub(); + rdt_pseudo_lock_release(); + rdtgroup_default.mode = RDT_MODE_SHAREABLE; + closid_exit(); + schemata_list_destroy(); + rdtgroup_destroy_root(); +} + static void rdt_kill_sb(struct super_block *sb) { struct rdt_resource *r; @@ -3091,12 +3107,7 @@ static void rdt_kill_sb(struct super_block *sb) for_each_alloc_capable_rdt_resource(r) resctrl_arch_reset_all_ctrls(r); - rmdir_all_sub(); - rdt_pseudo_lock_release(); - rdtgroup_default.mode = RDT_MODE_SHAREABLE; - closid_exit(); - schemata_list_destroy(); - rdtgroup_destroy_root(); + resctrl_fs_teardown(); if (resctrl_arch_alloc_capable()) resctrl_arch_disable_alloc(); if (resctrl_arch_mon_capable()) @@ -4127,6 +4138,8 @@ static int rdtgroup_setup_root(struct rdt_fs_context *ctx) static void rdtgroup_destroy_root(void) { + lockdep_assert_held(&rdtgroup_mutex); + kernfs_destroy_root(rdt_root); rdtgroup_default.kn = NULL; } @@ -4441,23 +4454,42 @@ static bool __exit resctrl_online_domains_exist(void) return false; } -/* +/** * resctrl_exit() - Remove the resctrl filesystem and free resources. * + * Called by the architecture code in response to a fatal error. + * Removes resctrl files and structures from kernfs to prevent further + * configuration. + * * When called by the architecture code, all CPUs and resctrl domains must be * offline. This ensures the limbo and overflow handlers are not scheduled to * run, meaning the data structures they access can be freed by * resctrl_mon_resource_exit(). + * + * After resctrl_exit() returns, the architecture code should return an + * error from all resctrl_arch_ functions that can do this. + * resctrl_arch_get_resource() must continue to return struct rdt_resources + * with the correct rid field to ensure the filesystem can be unmounted. */ void __exit resctrl_exit(void) { cpus_read_lock(); WARN_ON_ONCE(resctrl_online_domains_exist()); + + mutex_lock(&rdtgroup_mutex); + resctrl_fs_teardown(); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); debugfs_remove_recursive(debugfs_resctrl); + debugfs_resctrl = NULL; unregister_filesystem(&rdt_fs_type); - sysfs_remove_mount_point(fs_kobj, "resctrl"); + + /* + * Do not remove the sysfs mount point added by resctrl_init() so that + * it can be used to umount resctrl. + */ resctrl_mon_resource_exit(); } |