[PATCH] fs: nfs: Error if a port is unregistered

[PATCH] fs: nfs: Error if a port is unregistered

[John Watts]

If a server doesn't provide a service the port lookup will return 0.
Check for this and return an appropriate error code.

This was tested by running NFS with UDP disabled, which seems to be
the default in Arch at least.

Signed-off-by: John Watts <contact@jookia.org>
---
 fs/nfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nfs.c b/fs/nfs.c
index 446d0f7946..696630684e 100644
--- a/fs/nfs.c
+++ b/fs/nfs.c
@@ -571,6 +571,9 @@ static int rpc_lookup_req(struct nfs_priv *npriv, uint32_t prog, uint32_t ver)
 
 	nfs_free_packet(nfs_packet);
 
+	if (port == 0)
+		return -ENOENT;
+
 	return port;
 }
 
-- 
2.39.1

Re: [PATCH] fs: nfs: Error if a port is unregistered

[Sascha Hauer]

On Thu, Feb 02, 2023 at 09:34:04AM +1100, John Watts wrote:
> If a server doesn't provide a service the port lookup will return 0.
> Check for this and return an appropriate error code.
> 
> This was tested by running NFS with UDP disabled, which seems to be
> the default in Arch at least.
> 
> Signed-off-by: John Watts <contact@jookia.org>
> ---
>  fs/nfs.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/nfs.c b/fs/nfs.c
> index 446d0f7946..696630684e 100644
> --- a/fs/nfs.c
> +++ b/fs/nfs.c
> @@ -571,6 +571,9 @@ static int rpc_lookup_req(struct nfs_priv *npriv, uint32_t prog, uint32_t ver)
>  
>  	nfs_free_packet(nfs_packet);
>  
> +	if (port == 0)
> +		return -ENOENT;
> +

When this happens do we see a meaningful error message on the barebox
side? From a feeling I would say -ECONNREFUSED might be a better error
code, but I don't know if that's suitable for UDP connections.

Sascha

-- 
Pengutronix e.K.                           |                             |
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Re: [PATCH] fs: nfs: Error if a port is unregistered

[Jookia]

On Thu, Feb 02, 2023 at 08:39:48AM +0100, Sascha Hauer wrote:
> When this happens do we see a meaningful error message on the barebox
> side? From a feeling I would say -ECONNREFUSED might be a better error
> code, but I don't know if that's suitable for UDP connections.

Currently the error looks like this:

mounting failed with -110
ERROR: nfs nfs0: probe failed: Connection timed out
mount: Invalid argument
    probe-> nfs0
lookup mount port failed with -110
ERROR: nfs nfs0: probe failed: Connection timed out

Now it looks like:

lookup mount port failed with -2
ERROR: nfs nfs0: probe failed: No such file or directory
mount: Invalid argument
    probe-> nfs0

Not sure how this could be improved.

> Sascha

John.

Re: [PATCH] fs: nfs: Error if a port is unregistered

[Ahmad Fatoum]

On 02.02.23 10:33, Jookia wrote:
> On Thu, Feb 02, 2023 at 08:39:48AM +0100, Sascha Hauer wrote:
>> When this happens do we see a meaningful error message on the barebox
>> side? From a feeling I would say -ECONNREFUSED might be a better error
>> code, but I don't know if that's suitable for UDP connections.
> 
> Currently the error looks like this:
> 
> mounting failed with -110
> ERROR: nfs nfs0: probe failed: Connection timed out
> mount: Invalid argument
>     probe-> nfs0
> lookup mount port failed with -110
> ERROR: nfs nfs0: probe failed: Connection timed out
> 
> Now it looks like:
> 
> lookup mount port failed with -2
> ERROR: nfs nfs0: probe failed: No such file or directory
> mount: Invalid argument
>     probe-> nfs0
> 
> Not sure how this could be improved.

Add a pr_warn with a descriptive message?

> 
>> Sascha
> 
> John.
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH] fs: nfs: Error if a port is unregistered

[John Watts]

On Thu, Feb 02, 2023 at 10:45:05AM +0100, Ahmad Fatoum wrote:
> Add a pr_warn with a descriptive message?

Something like "hint: check your nfs server supports UDP"?

John.

Re: [PATCH] fs: nfs: Error if a port is unregistered

[Ahmad Fatoum]

On 02.02.23 11:31, John Watts wrote:
> On Thu, Feb 02, 2023 at 10:45:05AM +0100, Ahmad Fatoum wrote:
>> Add a pr_warn with a descriptive message?
> 
> Something like "hint: check your nfs server supports UDP"?

Or maybe: "No UDP port announced. Is the NFS server TCP-only?"

Cheers,
Ahmad

> 
> John.
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

[PATCH v2] fs: nfs: Error if a port is unregistered

[John Watts]

If a server doesn't provide a service the port lookup will return 0.

Check for this, return an appropriate error code and give a hint as to
why this might be happening.

This was tested by running NFS with UDP disabled, which seems to be
the default in Arch at least.

Signed-off-by: John Watts <contact@jookia.org>
---
Changes v1 -> v2:
- Added error message
---
 fs/nfs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/nfs.c b/fs/nfs.c
index 446d0f7946..1a0b28442d 100644
--- a/fs/nfs.c
+++ b/fs/nfs.c
@@ -571,6 +571,12 @@ static int rpc_lookup_req(struct nfs_priv *npriv, uint32_t prog, uint32_t ver)
 
 	nfs_free_packet(nfs_packet);
 
+	if (port == 0) {
+		pr_warn("No UDP port for RPC program %i! "
+		        "Is your NFS server TCP only?\n", prog);
+		return -ENOENT;
+	}
+
 	return port;
 }
 
-- 
2.39.1

Re: [PATCH v2] fs: nfs: Error if a port is unregistered

[Sascha Hauer]

On Thu, Feb 02, 2023 at 10:20:24PM +1100, John Watts wrote:
> If a server doesn't provide a service the port lookup will return 0.
> 
> Check for this, return an appropriate error code and give a hint as to
> why this might be happening.
> 
> This was tested by running NFS with UDP disabled, which seems to be
> the default in Arch at least.
> 
> Signed-off-by: John Watts <contact@jookia.org>
> ---
> Changes v1 -> v2:
> - Added error message
> ---
>  fs/nfs.c | 6 ++++++
>  1 file changed, 6 insertions(+)

Applied, thanks

Sascha

> 
> diff --git a/fs/nfs.c b/fs/nfs.c
> index 446d0f7946..1a0b28442d 100644
> --- a/fs/nfs.c
> +++ b/fs/nfs.c
> @@ -571,6 +571,12 @@ static int rpc_lookup_req(struct nfs_priv *npriv, uint32_t prog, uint32_t ver)
>  
>  	nfs_free_packet(nfs_packet);
>  
> +	if (port == 0) {
> +		pr_warn("No UDP port for RPC program %i! "
> +		        "Is your NFS server TCP only?\n", prog);
> +		return -ENOENT;
> +	}
> +
>  	return port;
>  }
>  
> -- 
> 2.39.1
> 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |