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| author | Tejun Heo <tj@kernel.org> | 2013-06-28 16:24:10 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-07-12 12:34:01 -0700 |
| commit | b1f28d3109349899e87377e89f9d8ab5bc95ec57 (patch) | |
| tree | 817a277b89882a82e5e52fd3911d81b819709c41 /kernel | |
| parent | 8f89140ae41ccd9c63344e6823faa862aa7435e3 (diff) | |
| download | linux-b1f28d3109349899e87377e89f9d8ab5bc95ec57.tar.gz linux-b1f28d3109349899e87377e89f9d8ab5bc95ec57.tar.bz2 linux-b1f28d3109349899e87377e89f9d8ab5bc95ec57.zip | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 09bfa870e698..9b16d75bec63 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -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) |