cgroup: remove cgroup_add_file[s]()

No controller is using cgroup_add_files[s]().  Unexport them, and
convert cgroup_add_files() to handle NULL entry terminated array
instead of taking count explicitly and continue creation on failure
for internal use.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>

2 files changed, 20 insertions, 47 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index af6211c7a42b..7a3d96755114 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -404,22 +404,6 @@ struct cgroup_scanner {
         void *data;
 };
 
-/*
- * Add a new file to the given cgroup directory. Should only be
- * called by subsystems from within a populate() method
- */
-int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
-                       const struct cftype *cft);
-
-/*
- * Add a set of new files to the given cgroup directory. Should
- * only be called by subsystems from within a populate() method
- */
-int cgroup_add_files(struct cgroup *cgrp,
-                        struct cgroup_subsys *subsys,
-                        const struct cftype cft[],
-                        int count);
-
 int cgroup_add_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts);
 
 int cgroup_is_removed(const struct cgroup *cgrp);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 835ae29e4ea2..fb71a930ec8d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2615,9 +2615,8 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
         return mode;
 }
 
-int cgroup_add_file(struct cgroup *cgrp,
-                       struct cgroup_subsys *subsys,
-                       const struct cftype *cft)
+static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
+                           const struct cftype *cft)
 {
         struct dentry *dir = cgrp->dentry;
         struct dentry *dentry;
@@ -2649,22 +2648,23 @@ int cgroup_add_file(struct cgroup *cgrp,
                 error = PTR_ERR(dentry);
         return error;
 }
-EXPORT_SYMBOL_GPL(cgroup_add_file);
 
-int cgroup_add_files(struct cgroup *cgrp,
-                        struct cgroup_subsys *subsys,
-                        const struct cftype cft[],
-                        int count)
+static int cgroup_add_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
+                            const struct cftype cfts[])
 {
-        int i, err;
-        for (i = 0; i < count; i++) {
-                err = cgroup_add_file(cgrp, subsys, &cft[i]);
-                if (err)
-                        return err;
+        const struct cftype *cft;
+        int err, ret = 0;
+
+        for (cft = cfts; cft->name[0] != '\0'; cft++) {
+                err = cgroup_add_file(cgrp, subsys, cft);
+                if (err) {
+                        pr_warning("cgroup_add_files: failed to create %s, err=%d\n",
+                                   cft->name, err);
+                        ret = err;
+                }
         }
-        return 0;
+        return ret;
 }
-EXPORT_SYMBOL_GPL(cgroup_add_files);
 
 static DEFINE_MUTEX(cgroup_cft_mutex);
 
@@ -2688,10 +2688,6 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
 {
         LIST_HEAD(pending);
         struct cgroup *cgrp, *n;
-        int count = 0;
-
-        while (cfts[count].name[0] != '\0')
-                count++;
 
         /* %NULL @cfts indicates abort and don't bother if @ss isn't attached */
         if (cfts && ss->root != &rootnode) {
@@ -2713,7 +2709,7 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
                 mutex_lock(&inode->i_mutex);
                 mutex_lock(&cgroup_mutex);
                 if (!cgroup_is_removed(cgrp))
-                        cgroup_add_files(cgrp, ss, cfts, count);
+                        cgroup_add_files(cgrp, ss, cfts);
                 mutex_unlock(&cgroup_mutex);
                 mutex_unlock(&inode->i_mutex);
 
@@ -3739,6 +3735,7 @@ static struct cftype files[] = {
                 .write_string = cgroup_release_agent_write,
                 .max_write_len = PATH_MAX,
         },
+        { }     /* terminate */
 };
 
 static int cgroup_populate_dir(struct cgroup *cgrp)
@@ -3746,7 +3743,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp)
         int err;
         struct cgroup_subsys *ss;
 
-        err = cgroup_add_files(cgrp, NULL, files, ARRAY_SIZE(files));
+        err = cgroup_add_files(cgrp, NULL, files);
         if (err < 0)
                 return err;
 
@@ -3757,16 +3754,8 @@ static int cgroup_populate_dir(struct cgroup *cgrp)
                 if (ss->populate && (err = ss->populate(ss, cgrp)) < 0)
                         return err;
 
-                list_for_each_entry(set, &ss->cftsets, node) {
-                        const struct cftype *cft;
-
-                        for (cft = set->cfts; cft->name[0] != '\0'; cft++) {
-                                err = cgroup_add_file(cgrp, ss, cft);
-                                if (err)
-                                        pr_warning("cgroup_populate_dir: failed to create %s, err=%d\n",
-                                                   cft->name, err);
-                        }
-                }
+                list_for_each_entry(set, &ss->cftsets, node)
+                        cgroup_add_files(cgrp, ss, set->cfts);
         }
 
         /* This cgroup is ready now */