From: Babu Moger babu.moger@amd.com
The default resource group and its files are created during kernel init time. Upcoming changes will make some resctrl files optional based on a mount parameter. If optional files are to be added to the default group based on the mount option, then each new file needs to be created separately and call kernfs_activate() again.
Create all files of the default resource group during resctrl mount, destroyed during unmount, to avoid scattering resctrl file addition across two separate code flows.
Signed-off-by: Babu Moger babu.moger@amd.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Reviewed-by: Peter Newman peternewman@google.com Reviewed-by: Tan Shaopeng tan.shaopeng@jp.fujitsu.com Reviewed-by: Fenghua Yu fenghua.yu@intel.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Tested-by: Peter Newman peternewman@google.com Tested-by: Tan Shaopeng tan.shaopeng@jp.fujitsu.com Link: https://lore.kernel.org/r/20231017002308.134480-6-babu.moger@amd.com --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 58 +++++++++++++++----------- 1 file changed, 34 insertions(+), 24 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index d1b5fd70ccbb..55da93b5ca53 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -54,6 +54,9 @@ static struct kernfs_node *kn_mondata; static struct seq_buf last_cmd_status; static char last_cmd_status_buf[512];
+static int rdtgroup_setup_root(struct rdt_fs_context *ctx); +static void rdtgroup_destroy_root(void); + struct dentry *debugfs_resctrl;
void rdt_last_cmd_clear(void) @@ -2529,10 +2532,14 @@ static int rdt_get_tree(struct fs_context *fc) goto out; }
- ret = rdt_enable_ctx(ctx); + ret = rdtgroup_setup_root(ctx); if (ret) goto out;
+ ret = rdt_enable_ctx(ctx); + if (ret) + goto out_root; + ret = schemata_list_create(); if (ret) { schemata_list_destroy(); @@ -2541,6 +2548,12 @@ static int rdt_get_tree(struct fs_context *fc)
closid_init();
+ ret = rdtgroup_add_files(rdtgroup_default.kn, RFTYPE_CTRL_BASE); + if (ret) + goto out_schemata_free; + + kernfs_activate(rdtgroup_default.kn); + ret = rdtgroup_create_info_dir(rdtgroup_default.kn); if (ret < 0) goto out_schemata_free; @@ -2597,6 +2610,8 @@ static int rdt_get_tree(struct fs_context *fc) schemata_list_destroy(); out_ctx: rdt_disable_ctx(); +out_root: + rdtgroup_destroy_root(); out: rdt_last_cmd_clear(); mutex_unlock(&rdtgroup_mutex); @@ -2667,7 +2682,6 @@ static int rdt_init_fs_context(struct fs_context *fc) if (!ctx) return -ENOMEM;
- ctx->kfc.root = rdt_root; ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; fc->fs_private = &ctx->kfc; fc->ops = &rdt_fs_context_ops; @@ -2837,6 +2851,7 @@ static void rdt_kill_sb(struct super_block *sb) rdt_pseudo_lock_release(); rdtgroup_default.mode = RDT_MODE_SHAREABLE; schemata_list_destroy(); + rdtgroup_destroy_root(); static_branch_disable_cpuslocked(&rdt_alloc_enable_key); static_branch_disable_cpuslocked(&rdt_mon_enable_key); static_branch_disable_cpuslocked(&rdt_enable_key); @@ -3718,10 +3733,8 @@ static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { .show_options = rdtgroup_show_options, };
-static int __init rdtgroup_setup_root(void) +static int rdtgroup_setup_root(struct rdt_fs_context *ctx) { - int ret; - rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, KERNFS_ROOT_CREATE_DEACTIVATED | KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK, @@ -3729,6 +3742,20 @@ static int __init rdtgroup_setup_root(void) if (IS_ERR(rdt_root)) return PTR_ERR(rdt_root);
+ ctx->kfc.root = rdt_root; + rdtgroup_default.kn = kernfs_root_to_node(rdt_root); + + return 0; +} + +static void rdtgroup_destroy_root(void) +{ + kernfs_destroy_root(rdt_root); + rdtgroup_default.kn = NULL; +} + +static void __init rdtgroup_setup_default(void) +{ mutex_lock(&rdtgroup_mutex);
rdtgroup_default.closid = 0; @@ -3738,19 +3765,7 @@ static int __init rdtgroup_setup_root(void)
list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
- ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RFTYPE_CTRL_BASE); - if (ret) { - kernfs_destroy_root(rdt_root); - goto out; - } - - rdtgroup_default.kn = kernfs_root_to_node(rdt_root); - kernfs_activate(rdtgroup_default.kn); - -out: mutex_unlock(&rdtgroup_mutex); - - return ret; }
static void domain_destroy_mon_state(struct rdt_domain *d) @@ -3872,13 +3887,11 @@ int __init rdtgroup_init(void) seq_buf_init(&last_cmd_status, last_cmd_status_buf, sizeof(last_cmd_status_buf));
- ret = rdtgroup_setup_root(); - if (ret) - return ret; + rdtgroup_setup_default();
ret = sysfs_create_mount_point(fs_kobj, "resctrl"); if (ret) - goto cleanup_root; + return ret;
ret = register_filesystem(&rdt_fs_type); if (ret) @@ -3911,8 +3924,6 @@ int __init rdtgroup_init(void)
cleanup_mountpoint: sysfs_remove_mount_point(fs_kobj, "resctrl"); -cleanup_root: - kernfs_destroy_root(rdt_root);
return ret; } @@ -3922,5 +3933,4 @@ void __exit rdtgroup_exit(void) debugfs_remove_recursive(debugfs_resctrl); unregister_filesystem(&rdt_fs_type); sysfs_remove_mount_point(fs_kobj, "resctrl"); - kernfs_destroy_root(rdt_root); }