[PATCH RFC 16/27] sched/psi: let procfs own the seq_file of the pressure files

[Christian Brauner]

Declare the show functions and let procfs open and free the seq_file of
/proc/pressure/*. That makes the open functions unnecessary and
->proc_release() only destroys the trigger now.

Signed-off-by: Christian Brauner (Amutable) <brauner at kernel.org>
---
 kernel/sched/psi.c | 38 +++++---------------------------------
 1 file changed, 5 insertions(+), 33 deletions(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 7c5381423334..bcb8bf4e0b69 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1535,21 +1535,6 @@ static int psi_cpu_show(struct seq_file *m, void *v)
 	return psi_show(m, &psi_system, PSI_CPU);
 }
 
-static int psi_io_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, psi_io_show, NULL);
-}
-
-static int psi_memory_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, psi_memory_show, NULL);
-}
-
-static int psi_cpu_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, psi_cpu_show, NULL);
-}
-
 static ssize_t psi_write(struct file *file, const char __user *user_buf,
 			 size_t nbytes, enum psi_res res)
 {
@@ -1635,31 +1620,25 @@ static int psi_fop_release(struct inode *inode, struct file *file)
 	struct seq_file *seq = file->private_data;
 
 	psi_trigger_destroy(seq->private);
-	return single_release(inode, file);
+	return 0;
 }
 
 static const struct proc_ops psi_io_proc_ops = {
-	.proc_open	= psi_io_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
+	.proc_show	= psi_io_show,
 	.proc_write	= psi_io_write,
 	.proc_poll	= psi_fop_poll,
 	.proc_release	= psi_fop_release,
 };
 
 static const struct proc_ops psi_memory_proc_ops = {
-	.proc_open	= psi_memory_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
+	.proc_show	= psi_memory_show,
 	.proc_write	= psi_memory_write,
 	.proc_poll	= psi_fop_poll,
 	.proc_release	= psi_fop_release,
 };
 
 static const struct proc_ops psi_cpu_proc_ops = {
-	.proc_open	= psi_cpu_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
+	.proc_show	= psi_cpu_show,
 	.proc_write	= psi_cpu_write,
 	.proc_poll	= psi_fop_poll,
 	.proc_release	= psi_fop_release,
@@ -1671,11 +1650,6 @@ static int psi_irq_show(struct seq_file *m, void *v)
 	return psi_show(m, &psi_system, PSI_IRQ);
 }
 
-static int psi_irq_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, psi_irq_show, NULL);
-}
-
 static ssize_t psi_irq_write(struct file *file, const char __user *user_buf,
 			     size_t nbytes, loff_t *ppos)
 {
@@ -1683,9 +1657,7 @@ static ssize_t psi_irq_write(struct file *file, const char __user *user_buf,
 }
 
 static const struct proc_ops psi_irq_proc_ops = {
-	.proc_open	= psi_irq_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
+	.proc_show	= psi_irq_show,
 	.proc_write	= psi_irq_write,
 	.proc_poll	= psi_fop_poll,
 	.proc_release	= psi_fop_release,

-- 
2.53.0