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author | 2014-02-13 06:58:38 -0500 | |
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committer | 2014-02-13 06:58:38 -0500 | |
commit | 35585573055f37837eb752ee22eb5523682ca742 (patch) | |
tree | 6cf006b6409e6256ca4d3a81eb5701cde931a324 /kernel | |
parent | cgroup: disallow xattr, release_agent and name if sane_behavior (diff) | |
download | linux-35585573055f37837eb752ee22eb5523682ca742.tar.gz linux-35585573055f37837eb752ee22eb5523682ca742.tar.bz2 linux-35585573055f37837eb752ee22eb5523682ca742.zip |
cgroup: drop CGRP_ROOT_SUBSYS_BOUND
Before kernfs conversion, due to the way super_block lookup works,
cgroup roots were created and made visible before being fully
initialized. This in turn required a special flag to mark that the
root hasn't been fully initialized so that the destruction path can
tell fully bound ones from half initialized.
That flag is CGRP_ROOT_SUBSYS_BOUND and no longer necessary after the
kernfs conversion as the lookup and creation of new root are atomic
w.r.t. cgroup_mutex. This patch removes the flag and passes the
requests subsystem mask to cgroup_setup_root() so that it can set the
respective mask bits as subsystems are bound.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cgroup.c | 28 |
1 files changed, 4 insertions, 24 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 079c478a4735..878cd1810ad1 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -733,7 +733,6 @@ static void cgroup_destroy_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; struct cgrp_cset_link *link, *tmp_link; - int ret; mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); @@ -742,11 +741,7 @@ static void cgroup_destroy_root(struct cgroupfs_root *root) BUG_ON(!list_empty(&cgrp->children)); /* Rebind all subsystems back to the default hierarchy */ - if (root->flags & CGRP_ROOT_SUBSYS_BOUND) { - ret = rebind_subsystems(root, 0, root->subsys_mask); - /* Shouldn't be able to fail ... */ - BUG_ON(ret); - } + WARN_ON(rebind_subsystems(root, 0, root->subsys_mask)); /* * Release all the links from cset_links to this hierarchy's @@ -1055,13 +1050,7 @@ static int rebind_subsystems(struct cgroupfs_root *root, } } - /* - * Mark @root has finished binding subsystems. @root->subsys_mask - * now matches the bound subsystems. - */ - root->flags |= CGRP_ROOT_SUBSYS_BOUND; kernfs_activate(cgrp->kn); - return 0; } @@ -1353,15 +1342,6 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) init_cgroup_root(root); - /* - * We need to set @root->subsys_mask now so that @root can be - * matched by cgroup_test_super() before it finishes - * initialization; otherwise, competing mounts with the same - * options may try to bind the same subsystems instead of waiting - * for the first one leading to unexpected mount errors. - * SUBSYS_BOUND will be set once actual binding is complete. - */ - root->subsys_mask = opts->subsys_mask; root->flags = opts->flags; if (opts->release_agent) strcpy(root->release_agent_path, opts->release_agent); @@ -1372,7 +1352,7 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) return root; } -static int cgroup_setup_root(struct cgroupfs_root *root) +static int cgroup_setup_root(struct cgroupfs_root *root, unsigned long ss_mask) { LIST_HEAD(tmp_links); struct cgroup *root_cgrp = &root->top_cgroup; @@ -1415,7 +1395,7 @@ static int cgroup_setup_root(struct cgroupfs_root *root) if (ret) goto destroy_root; - ret = rebind_subsystems(root, root->subsys_mask, 0); + ret = rebind_subsystems(root, ss_mask, 0); if (ret) goto destroy_root; @@ -1532,7 +1512,7 @@ retry: goto out_unlock; } - ret = cgroup_setup_root(root); + ret = cgroup_setup_root(root, opts.subsys_mask); if (ret) cgroup_free_root(root); |