From: Fenghua Yu <fenghua...@intel.com>
Four basic file system commands are implement for resctrl.
mount, umount, mkdir, and rmdir.
Signed-off-by: Fenghua Yu <fenghua...@intel.com>
Reviewed-by: Tony Luck <tony.l...@intel.com>
---
arch/x86/include/asm/intel_rdt_rdtgroup.h | 1 +
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 211 ++++++++++++++++++++++++++++++
2 files changed, 212 insertions(+)
diff --git a/arch/x86/include/asm/intel_rdt_rdtgroup.h
b/arch/x86/include/asm/intel_rdt_rdtgroup.h
index 92208a2..43a3b83 100644
--- a/arch/x86/include/asm/intel_rdt_rdtgroup.h
+++ b/arch/x86/include/asm/intel_rdt_rdtgroup.h
@@ -10,6 +10,7 @@
/* Defined in intel_rdt_rdtgroup.c.*/
extern int __init rdtgroup_init(void);
extern void rdtgroup_exit(struct task_struct *tsk);
+extern bool rdtgroup_mounted;
/* Defined in intel_rdt.c. */
extern struct list_head rdtgroup_lists;
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index acea62c..71231ba 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -51,6 +51,13 @@ static int rdt_info_show(struct seq_file *seq, void *v);
static int rdt_max_closid_show(struct seq_file *seq, void *v);
static int rdt_max_cbm_len_show(struct seq_file *seq, void *v);
static int domain_to_cache_id_show(struct seq_file *seq, void *v);
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode);
+static int rdtgroup_rmdir(struct kernfs_node *kn);
+static struct dentry *rdt_mount(struct file_system_type *fs_type,
+ int flags, const char *unused_dev_name,
+ void *data);
+static void rdt_kill_sb(struct super_block *sb);
/* rdtgroup core interface files */
static struct rftype rdtgroup_root_base_files[] = {
@@ -112,12 +119,24 @@ static struct rftype rdtgroup_partition_base_files[] = {
},
};
+static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
+ .mkdir = rdtgroup_mkdir,
+ .rmdir = rdtgroup_rmdir,
+};
+
+static struct file_system_type rdt_fs_type = {
+ .name = "resctrl",
+ .mount = rdt_mount,
+ .kill_sb = rdt_kill_sb,
+};
+
struct rdtgroup *root_rdtgrp;
static struct rftype rdtgroup_partition_base_files[];
struct cache_domain cache_domains[MAX_CACHE_LEAVES];
/* The default hierarchy. */
struct rdtgroup_root rdtgrp_dfl_root;
static struct list_head rdtgroups;
+bool rdtgroup_mounted;
/*
* kernfs_root - find out the kernfs_root a kernfs_node belongs to
@@ -730,6 +749,110 @@ static void rdtgroup_destroy_locked(struct rdtgroup
*rdtgrp)
kernfs_remove(rdtgrp->kn);
}
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode)
+{
+ struct rdtgroup *parent, *rdtgrp;
+ struct rdtgroup_root *root;
+ struct kernfs_node *kn;
+ int ret;
+
+ if (parent_kn != root_rdtgrp->kn)
+ return -EPERM;
+
+ /* Do not accept '\n' to avoid unparsable situation.
+ */
+ if (strchr(name, '\n'))
+ return -EINVAL;
+
+ parent = rdtgroup_kn_lock_live(parent_kn);
+ if (!parent)
+ return -ENODEV;
+ root = parent->root;
+
+ /* allocate the rdtgroup. */
+ rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
+ if (!rdtgrp) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ INIT_LIST_HEAD(&rdtgrp->pset.tasks);
+
+ cpumask_clear(&rdtgrp->cpu_mask);
+
+ rdtgrp->root = root;
+
+ /* create the directory */
+ kn = kernfs_create_dir(parent->kn, name, mode, rdtgrp);
+ if (IS_ERR(kn)) {
+ ret = PTR_ERR(kn);
+ goto out_cancel_ref;
+ }
+ rdtgrp->kn = kn;
+
+ /*
+ * This extra ref will be put in kernfs_remove() and guarantees
+ * that @rdtgrp->kn is always accessible.
+ */
+ kernfs_get(kn);
+
+ atomic_inc(&root->nr_rdtgrps);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+
+ ret = rdtgroup_partition_populate_dir(kn);
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn);
+
+ list_add_tail(&rdtgrp->rdtgroup_list, &rdtgroup_lists);
+ /* Generate default schema for rdtgrp. */
+ ret = get_default_resources(rdtgrp);
+ if (ret)
+ goto out_destroy;
+
+ ret = 0;
+ goto out_unlock;
+
+out_cancel_ref:
+ kfree(rdtgrp);
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+
+out_destroy:
+ rdtgroup_destroy_locked(rdtgrp);
+ goto out_unlock;
+}
+
+static int rdtgroup_rmdir(struct kernfs_node *kn)
+{
+ struct rdtgroup *rdtgrp;
+ int cpu;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(kn);
+ if (!rdtgrp)
+ return -ENODEV;
+
+ if (!list_empty(&rdtgrp->pset.tasks)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ for_each_cpu(cpu, &rdtgrp->cpu_mask)
+ per_cpu(cpu_rdtgroup, cpu) = root_rdtgrp;
+
+ rdtgroup_destroy_locked(rdtgrp);
+
+out:
+ rdtgroup_kn_unlock(kn);
+ return ret;
+}
static int
rdtgroup_move_task_all(struct rdtgroup *src_rdtgrp, struct rdtgroup
*dst_rdtgrp)
{
@@ -978,3 +1101,91 @@ void rdtgroup_fork(struct task_struct *child)
out:
mutex_unlock(&rdtgroup_mutex);
}
+
+static struct dentry *rdt_mount(struct file_system_type *fs_type,
+ int flags, const char *unused_dev_name,
+ void *data)
+{
+ struct super_block *pinned_sb = NULL;
+ struct rdtgroup_root *root;
+ struct dentry *dentry;
+ int ret;
+ bool new_sb;
+
+ /*
+ * The first time anyone tries to mount a rdtgroup, enable the list
+ * linking tasks and fix up all existing tasks.
+ */
+ if (rdtgroup_mounted)
+ return ERR_PTR(-EBUSY);
+
+ rdt_opts.cdp_enabled = false;
+ rdt_opts.verbose = false;
+ cdp_enabled = false;
+
+ ret = parse_rdtgroupfs_options(data);
+ if (ret)
+ goto out_mount;
+
+ if (rdt_opts.cdp_enabled) {
+ cdp_enabled = true;
+ cconfig.max_closid >>= cdp_enabled;
+ pr_info("CDP is enabled\n");
+ }
+
+ init_msrs(cdp_enabled);
+
+ root = &rdtgrp_dfl_root;
+
+ ret = get_default_resources(&root->rdtgrp);
+ if (ret)
+ return ERR_PTR(-ENOSPC);
+
+out_mount:
+ dentry = kernfs_mount(fs_type, flags, root->kf_root,
+ RDTGROUP_SUPER_MAGIC,
+ &new_sb);
+ if (IS_ERR(dentry) || !new_sb)
+ goto out_unlock;
+
+ /*
+ * If @pinned_sb, we're reusing an existing root and holding an
+ * extra ref on its sb. Mount is complete. Put the extra ref.
+ */
+ if (pinned_sb) {
+ WARN_ON(new_sb);
+ deactivate_super(pinned_sb);
+ }
+
+ INIT_LIST_HEAD(&root->rdtgrp.pset.tasks);
+
+ cpumask_copy(&root->rdtgrp.cpu_mask, cpu_online_mask);
+ static_key_slow_inc(&rdt_enable_key);
+ rdtgroup_mounted = true;
+
+ return dentry;
+
+out_unlock:
+ return ERR_PTR(ret);
+}
+
+static void rdt_kill_sb(struct super_block *sb)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ rmdir_all_sub();
+
+ static_key_slow_dec(&rdt_enable_key);
+
+ release_root_closid();
+ root_rdtgrp->resource.valid = false;
+
+ /* Restore max_closid to original value. */
+ cconfig.max_closid <<= cdp_enabled;
+
+ kernfs_kill_sb(sb);
+ INIT_LIST_HEAD(&root_rdtgrp->pset.tasks);
+ rdtgroup_mounted = false;
+
+ mutex_unlock(&rdtgroup_mutex);
+}
--
2.5.0
