diff mbox series

[RFC,v1,03/10] net: qrtr: support identical node ids

Message ID 20241018181842.1368394-4-denkenz@gmail.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series QRTR Multi-endpoint support | expand

Checks

Context Check Description
netdev/series_format warning Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 5 this patch: 6
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 7 this patch: 7
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 21 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Denis Kenzior Oct. 18, 2024, 6:18 p.m. UTC 
Add support for tracking multiple endpoints that may have conflicting
node identifiers. This is achieved by using both the node and endpoint
identifiers as the key inside the radix_tree data structure.

For backward compatibility with existing clients, the previous key
schema (node identifier only) is preserved. However, this schema will
only support the first endpoint/node combination.  This is acceptable
for legacy clients as support for multiple endpoints with conflicting
node identifiers was not previously possible.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Andy Gross <agross@kernel.org>
---
 net/qrtr/af_qrtr.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Comments

Simon Horman Oct. 19, 2024, 9:18 a.m. UTC | #1 
On Fri, Oct 18, 2024 at 01:18:21PM -0500, Denis Kenzior wrote:
> Add support for tracking multiple endpoints that may have conflicting
> node identifiers. This is achieved by using both the node and endpoint
> identifiers as the key inside the radix_tree data structure.
> 
> For backward compatibility with existing clients, the previous key
> schema (node identifier only) is preserved. However, this schema will
> only support the first endpoint/node combination.  This is acceptable
> for legacy clients as support for multiple endpoints with conflicting
> node identifiers was not previously possible.
> 
> Signed-off-by: Denis Kenzior <denkenz@gmail.com>
> Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
> Reviewed-by: Andy Gross <agross@kernel.org>
> ---
>  net/qrtr/af_qrtr.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c
> index be275871fb2a..e83d491a8da9 100644
> --- a/net/qrtr/af_qrtr.c
> +++ b/net/qrtr/af_qrtr.c
> @@ -418,12 +418,20 @@ static struct qrtr_node *qrtr_node_lookup(unsigned int nid)
>  static void qrtr_node_assign(struct qrtr_node *node, unsigned int nid)
>  {
>  	unsigned long flags;
> +	unsigned long key;
>  
>  	if (nid == QRTR_EP_NID_AUTO)
>  		return;
>  
>  	spin_lock_irqsave(&qrtr_nodes_lock, flags);
> -	radix_tree_insert(&qrtr_nodes, nid, node);
> +
> +	/* Always insert with the endpoint_id + node_id */
> +	key = (unsigned long)node->ep->id << 32 | nid;

Hi Denis,

On systems with 32-bit longs, such as ARM, this will overflow.

> +	radix_tree_insert(&qrtr_nodes, key, node);
> +
> +	if (!radix_tree_lookup(&qrtr_nodes, nid))
> +		radix_tree_insert(&qrtr_nodes, nid, node);
> +
>  	if (node->nid == QRTR_EP_NID_AUTO)
>  		node->nid = nid;
>  	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
> -- 
> 2.45.2
> 
>
Denis Kenzior Oct. 22, 2024, 2:24 p.m. UTC | #2 
Hi Simon,

> 
> On systems with 32-bit longs, such as ARM, this will overflow.

Indeed.  I mentioned this in the cover letter.

Regards,
-Denis
diff mbox series

Patch

diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c
index be275871fb2a..e83d491a8da9 100644
--- a/net/qrtr/af_qrtr.c
+++ b/net/qrtr/af_qrtr.c
@@ -418,12 +418,20 @@  static struct qrtr_node *qrtr_node_lookup(unsigned int nid)
 static void qrtr_node_assign(struct qrtr_node *node, unsigned int nid)
 {
 	unsigned long flags;
+	unsigned long key;
 
 	if (nid == QRTR_EP_NID_AUTO)
 		return;
 
 	spin_lock_irqsave(&qrtr_nodes_lock, flags);
-	radix_tree_insert(&qrtr_nodes, nid, node);
+
+	/* Always insert with the endpoint_id + node_id */
+	key = (unsigned long)node->ep->id << 32 | nid;
+	radix_tree_insert(&qrtr_nodes, key, node);
+
+	if (!radix_tree_lookup(&qrtr_nodes, nid))
+		radix_tree_insert(&qrtr_nodes, nid, node);
+
 	if (node->nid == QRTR_EP_NID_AUTO)
 		node->nid = nid;
 	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);