allow ->read_iter on debugfs

allow ->read_iter on debugfs

[Christoph Hellwig]

Hi Greg,

in my filesystem set_fs removel series I convert the seq_file interface
to be iov_iter based.  It turns out debugfs needs this little patch
to proxy read_iter as well.  Let me know if you are ok with me queueing
this up with the rest of the series.

[PATCH] debugfs: add a proxy stub for ->read_iter

[Christoph Hellwig]

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@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 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

Re: [PATCH] debugfs: add a proxy stub for ->read_iter

[Greg KH]

On Mon, Jul 13, 2020 at 09:37:29AM +0200, Christoph Hellwig wrote:
> 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@nvidia.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH] debugfs: add a proxy stub for ->read_iter

[Jon Hunter]

On 13/07/2020 09:38, Greg KH wrote:
> On Mon, Jul 13, 2020 at 09:37:29AM +0200, Christoph Hellwig wrote:
>> 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@nvidia.com>
>> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 


Tested-by: Jon Hunter <jonathanh@nvidia.com>

Cheers
Jon

-- 
nvpublic

Re: allow ->read_iter on debugfs

[Greg KH]

On Mon, Jul 13, 2020 at 09:37:28AM +0200, Christoph Hellwig wrote:
> Hi Greg,
> 
> in my filesystem set_fs removel series I convert the seq_file interface
> to be iov_iter based.  It turns out debugfs needs this little patch
> to proxy read_iter as well.  Let me know if you are ok with me queueing
> this up with the rest of the series.
> 
> 

No objection from me, please do so!

thanks,

greg k-h