cgroup: remove struct cgroup_seqfile_state

We can use struct cfent instead.

v2:
- remove cgroup_seqfile_release().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 13 insertions, 32 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 41b559f51502..ed2104304833 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2397,11 +2397,6 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf,
  * supports string->u64 maps, but can be extended in future.
  */
 
-struct cgroup_seqfile_state {
-        struct cftype *cft;
-        struct cgroup *cgroup;
-};
-
 static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
 {
         struct seq_file *sf = cb->state;
@@ -2410,59 +2405,45 @@ static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
 
 static int cgroup_seqfile_show(struct seq_file *m, void *arg)
 {
-        struct cgroup_seqfile_state *state = m->private;
-        struct cftype *cft = state->cft;
+        struct cfent *cfe = m->private;
+        struct cftype *cft = cfe->type;
+        struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent);
+
         if (cft->read_map) {
                 struct cgroup_map_cb cb = {
                         .fill = cgroup_map_add,
                         .state = m,
                 };
-                return cft->read_map(state->cgroup, cft, &cb);
+                return cft->read_map(cgrp, cft, &cb);
         }
-        return cft->read_seq_string(state->cgroup, cft, m);
-}
-
-static int cgroup_seqfile_release(struct inode *inode, struct file *file)
-{
-        struct seq_file *seq = file->private_data;
-        kfree(seq->private);
-        return single_release(inode, file);
+        return cft->read_seq_string(cgrp, cft, m);
 }
 
 static const struct file_operations cgroup_seqfile_operations = {
         .read = seq_read,
         .write = cgroup_file_write,
         .llseek = seq_lseek,
-        .release = cgroup_seqfile_release,
+        .release = single_release,
 };
 
 static int cgroup_file_open(struct inode *inode, struct file *file)
 {
         int err;
+        struct cfent *cfe;
         struct cftype *cft;
 
         err = generic_file_open(inode, file);
         if (err)
                 return err;
-        cft = __d_cft(file->f_dentry);
+        cfe = __d_cfe(file->f_dentry);
+        cft = cfe->type;
 
         if (cft->read_map || cft->read_seq_string) {
-                struct cgroup_seqfile_state *state;
-
-                state = kzalloc(sizeof(*state), GFP_USER);
-                if (!state)
-                        return -ENOMEM;
-
-                state->cft = cft;
-                state->cgroup = __d_cgrp(file->f_dentry->d_parent);
                 file->f_op = &cgroup_seqfile_operations;
-                err = single_open(file, cgroup_seqfile_show, state);
-                if (err < 0)
-                        kfree(state);
-        } else if (cft->open)
+                err = single_open(file, cgroup_seqfile_show, cfe);
+        } else if (cft->open) {
                 err = cft->open(inode, file);
-        else
-                err = 0;
+        }
 
         return err;
 }