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cgroup: open-code cgroup_create_dir()

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The operation order of cgroup creation is about to change and
cgroup_create_dir() is more of a hindrance than a proper abstraction.
Open-code it by moving the parent nlink adjustment next to self nlink
adjustment in cgroup_create_file() and the rest to cgroup_create().

This patch doesn't introduce any behavior change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2012-11-19 08:13:36 -08:00
parent 2243076ad1
commit 28fd6f30ac
1 changed files with 5 additions and 25 deletions
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30
kernel/cgroup.c
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@ -2652,6 +2652,7 @@ static int cgroup_create_file(struct dentry *dentry, umode_t mode,
/* start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
inc_nlink(dentry->d_parent->d_inode);
/* start with the directory inode held, so that we can
* populate it without racing with another mkdir */
@ -2666,30 +2667,6 @@ static int cgroup_create_file(struct dentry *dentry, umode_t mode,
return 0;
}
/*
* cgroup_create_dir - create a directory for an object.
* @cgrp: the cgroup we create the directory for. It must have a valid
* ->parent field. And we are going to fill its ->dentry field.
* @dentry: dentry of the new cgroup
* @mode: mode to set on new directory.
*/
static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry,
umode_t mode)
{
struct dentry *parent;
int error = 0;
parent = cgrp->parent->dentry;
error = cgroup_create_file(dentry, S_IFDIR | mode, cgrp->root->sb);
if (!error) {
dentry->d_fsdata = cgrp;
inc_nlink(parent->d_inode);
rcu_assign_pointer(cgrp->dentry, dentry);
}
return error;
}
/**
* cgroup_file_mode - deduce file mode of a control file
* @cft: the control file in question
@ -4138,10 +4115,13 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children);
root->number_of_cgroups++;
err = cgroup_create_dir(cgrp, dentry, mode);
err = cgroup_create_file(dentry, S_IFDIR | mode, sb);
if (err < 0)
goto err_remove;
dentry->d_fsdata = cgrp;
rcu_assign_pointer(cgrp->dentry, dentry);
for_each_subsys(root, ss) {
/* each css holds a ref to the cgroup's dentry */
dget(dentry);