Re: [PATCH 15/23] seq_file: switch over direct seq_read method calls to seq_read_iter

[Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>]

Please try this one:

---
From 5e86146296fbcd7593da1d9d39b9685a5e6b83be Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Date: Sat, 11 Jul 2020 08:46:10 +0200
Subject: debugfs: add a proxy stub for ->read_iter

debugfs registrations typically go through a set of proxy ops to deal
with refcounting, which need to support every method that can be
supported.  Add ->read_iter to the proxy ops to prepare for seq_file to
be switch to ->read_iter.

Reported-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 fs/debugfs/file.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 8ba32c2feb1b73..dcd7bdaf67417f 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -231,6 +231,10 @@ FULL_PROXY_FUNC(read, ssize_t, filp,
 			loff_t *ppos),
 		ARGS(filp, buf, size, ppos));
 
+FULL_PROXY_FUNC(read_iter, ssize_t, iocb->ki_filp,
+		PROTO(struct kiocb *iocb, struct iov_iter *iter),
+		ARGS(iocb, iter));
+
 FULL_PROXY_FUNC(write, ssize_t, filp,
 		PROTO(struct file *filp, const char __user *buf, size_t size,
 			loff_t *ppos),
@@ -286,6 +290,8 @@ static void __full_proxy_fops_init(struct file_operations *proxy_fops,
 		proxy_fops->llseek = full_proxy_llseek;
 	if (real_fops->read)
 		proxy_fops->read = full_proxy_read;
+	if (real_fops->read_iter)
+		proxy_fops->read_iter = full_proxy_read_iter;
 	if (real_fops->write)
 		proxy_fops->write = full_proxy_write;
 	if (real_fops->poll)
-- 
2.26.2