cgroup: fix error path of cgroup_addrm_files()

cgroup_addrm_files() mishandled error return value from
cgroup_add_file() and returns error iff the last file fails to create.
As we're in the process of cleaning up file add/rm error handling and
will reliably propagate file creation failures, there's no point in
keeping adding files after a failure.

Replace the broken error collection logic with immediate error return.
While at it, add lockdep assertions and function comment.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2013-06-28 16:24:10 -07:00
parent 8f89140ae4
commit b1f28d3109

View File

@ -2780,11 +2780,26 @@ out:
return error;
}
/**
* cgroup_addrm_files - add or remove files to a cgroup directory
* @cgrp: the target cgroup
* @subsys: the subsystem of files to be added
* @cfts: array of cftypes to be added
* @is_add: whether to add or remove
*
* Depending on @is_add, add or remove files defined by @cfts on @cgrp.
* All @cfts should belong to @subsys. For removals, this function never
* fails. If addition fails, this function doesn't remove files already
* added. The caller is responsible for cleaning up.
*/
static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
struct cftype cfts[], bool is_add)
{
struct cftype *cft;
int err, ret = 0;
int ret;
lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
lockdep_assert_held(&cgroup_mutex);
for (cft = cfts; cft->name[0] != '\0'; cft++) {
/* does cft->flags tell us to skip this file on @cgrp? */
@ -2796,16 +2811,17 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
continue;
if (is_add) {
err = cgroup_add_file(cgrp, subsys, cft);
if (err)
ret = cgroup_add_file(cgrp, subsys, cft);
if (ret) {
pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n",
cft->name, err);
ret = err;
cft->name, ret);
return ret;
}
} else {
cgroup_rm_file(cgrp, cft);
}
}
return ret;
return 0;
}
static void cgroup_cfts_prepare(void)