fs/proc/task_mmu.c: unify/simplify do_maps_open() and numa_maps_open()

do_maps_open() and numa_maps_open() are overcomplicated, they could use
__seq_open_private().  Plus they do the same, just sizeof(*priv)

Change them to use a new simple helper, proc_maps_open(ops, psize).  This
simplifies the code and allows us to do the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 28 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 289dfdc0ec09..4d716a09d500 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -231,23 +231,23 @@ static void m_stop(struct seq_file *m, void *v)
                 put_task_struct(priv->task);
 }
 
+static int proc_maps_open(struct inode *inode, struct file *file,
+                        const struct seq_operations *ops, int psize)
+{
+        struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
+
+        if (!priv)
+                return -ENOMEM;
+
+        priv->pid = proc_pid(inode);
+        return 0;
+}
+
 static int do_maps_open(struct inode *inode, struct file *file,
                         const struct seq_operations *ops)
 {
-        struct proc_maps_private *priv;
-        int ret = -ENOMEM;
-        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-        if (priv) {
-                priv->pid = proc_pid(inode);
-                ret = seq_open(file, ops);
-                if (!ret) {
-                        struct seq_file *m = file->private_data;
-                        m->private = priv;
-                } else {
-                        kfree(priv);
-                }
-        }
-        return ret;
+        return proc_maps_open(inode, file, ops,
+                                sizeof(struct proc_maps_private));
 }
 
 static void
@@ -1526,20 +1526,8 @@ static const struct seq_operations proc_tid_numa_maps_op = {
 static int numa_maps_open(struct inode *inode, struct file *file,
                           const struct seq_operations *ops)
 {
-        struct numa_maps_private *priv;
-        int ret = -ENOMEM;
-        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-        if (priv) {
-                priv->proc_maps.pid = proc_pid(inode);
-                ret = seq_open(file, ops);
-                if (!ret) {
-                        struct seq_file *m = file->private_data;
-                        m->private = priv;
-                } else {
-                        kfree(priv);
-                }
-        }
-        return ret;
+        return proc_maps_open(inode, file, ops,
+                                sizeof(struct numa_maps_private));
 }
 
 static int pid_numa_maps_open(struct inode *inode, struct file *file)