From cca8f32714d3a8bb4d109c9d7d790fd705b734e5 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Jan 2019 10:14:26 -0500 Subject: cgroup: store a reference to cgroup_ns into cgroup_fs_context ... and trim cgroup_do_mount() arguments (renaming it to cgroup_do_get_tree()) Signed-off-by: Al Viro --- kernel/cgroup/cgroup-internal.h | 4 ++-- kernel/cgroup/cgroup-v1.c | 8 +++----- kernel/cgroup/cgroup.c | 17 ++++++++++++----- 3 files changed, 17 insertions(+), 12 deletions(-) (limited to 'kernel/cgroup') diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index f7fd54f2973f..37cf709b7a0e 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -42,6 +42,7 @@ extern void __init enable_debug_cgroup(void); */ struct cgroup_fs_context { struct cgroup_root *root; + struct cgroup_namespace *ns; unsigned int flags; /* CGRP_ROOT_* flags */ /* cgroup1 bits */ @@ -212,8 +213,7 @@ void cgroup_free_root(struct cgroup_root *root); void init_cgroup_root(struct cgroup_fs_context *ctx); int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask); int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask); -int cgroup_do_mount(struct fs_context *fc, unsigned long magic, - struct cgroup_namespace *ns); +int cgroup_do_get_tree(struct fs_context *fc); int cgroup_migrate_vet_dst(struct cgroup *dst_cgrp); void cgroup_migrate_finish(struct cgroup_mgctx *mgctx); diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 0d71fc98e73d..571ef3447426 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -1145,7 +1145,6 @@ struct kernfs_syscall_ops cgroup1_kf_syscall_ops = { */ static int cgroup1_root_to_use(struct fs_context *fc) { - struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; struct cgroup_fs_context *ctx = cgroup_fc2context(fc); struct cgroup_root *root; struct cgroup_subsys *ss; @@ -1217,7 +1216,7 @@ static int cgroup1_root_to_use(struct fs_context *fc) return cg_invalf(fc, "cgroup1: No subsys list or none specified"); /* Hierarchies may only be created in the initial cgroup namespace. */ - if (ns != &init_cgroup_ns) + if (ctx->ns != &init_cgroup_ns) return -EPERM; root = kzalloc(sizeof(*root), GFP_KERNEL); @@ -1235,12 +1234,11 @@ static int cgroup1_root_to_use(struct fs_context *fc) int cgroup1_get_tree(struct fs_context *fc) { - struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; struct cgroup_fs_context *ctx = cgroup_fc2context(fc); int ret; /* Check if the caller has permission to mount. */ - if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) + if (!ns_capable(ctx->ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp); @@ -1252,7 +1250,7 @@ int cgroup1_get_tree(struct fs_context *fc) mutex_unlock(&cgroup_mutex); if (!ret) - ret = cgroup_do_mount(fc, CGROUP_SUPER_MAGIC, ns); + ret = cgroup_do_get_tree(fc); if (!ret && percpu_ref_is_dying(&ctx->root->cgrp.self.refcnt)) { struct super_block *sb = fc->root->d_sb; diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 64360a46d4df..0c6bef234a7c 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2036,13 +2036,17 @@ out: return ret; } -int cgroup_do_mount(struct fs_context *fc, unsigned long magic, - struct cgroup_namespace *ns) +int cgroup_do_get_tree(struct fs_context *fc) { struct cgroup_fs_context *ctx = cgroup_fc2context(fc); bool new_sb = false; + unsigned long magic; int ret = 0; + if (fc->fs_type == &cgroup2_fs_type) + magic = CGROUP2_SUPER_MAGIC; + else + magic = CGROUP_SUPER_MAGIC; fc->root = kernfs_mount(fc->fs_type, fc->sb_flags, ctx->root->kf_root, magic, &new_sb); if (IS_ERR(fc->root)) @@ -2052,7 +2056,7 @@ int cgroup_do_mount(struct fs_context *fc, unsigned long magic, * In non-init cgroup namespace, instead of root cgroup's dentry, * we return the dentry corresponding to the cgroupns->root_cgrp. */ - if (!ret && ns != &init_cgroup_ns) { + if (!ret && ctx->ns != &init_cgroup_ns) { struct dentry *nsdentry; struct super_block *sb = fc->root->d_sb; struct cgroup *cgrp; @@ -2060,7 +2064,7 @@ int cgroup_do_mount(struct fs_context *fc, unsigned long magic, mutex_lock(&cgroup_mutex); spin_lock_irq(&css_set_lock); - cgrp = cset_cgroup_from_root(ns->root_cset, ctx->root); + cgrp = cset_cgroup_from_root(ctx->ns->root_cset, ctx->root); spin_unlock_irq(&css_set_lock); mutex_unlock(&cgroup_mutex); @@ -2089,6 +2093,7 @@ static void cgroup_fs_context_free(struct fs_context *fc) kfree(ctx->name); kfree(ctx->release_agent); + put_cgroup_ns(ctx->ns); kfree(ctx); } @@ -2106,7 +2111,7 @@ static int cgroup_get_tree(struct fs_context *fc) cgroup_get_live(&cgrp_dfl_root.cgrp); ctx->root = &cgrp_dfl_root; - ret = cgroup_do_mount(fc, CGROUP2_SUPER_MAGIC, ns); + ret = cgroup_do_get_tree(fc); if (!ret) apply_cgroup_root_flags(ctx->flags); return ret; @@ -2144,6 +2149,8 @@ static int cgroup_init_fs_context(struct fs_context *fc) if (!use_task_css_set_links) cgroup_enable_task_cg_lists(); + ctx->ns = current->nsproxy->cgroup_ns; + get_cgroup_ns(ctx->ns); fc->fs_private = ctx; if (fc->fs_type == &cgroup2_fs_type) fc->ops = &cgroup_fs_context_ops; -- cgit v1.2.3