* [PATCH net-next] ax25: exit linked-list searches earlier
@ 2023-04-07 14:20 Peter Lafreniere
2023-04-07 15:14 ` Dan Carpenter
2023-04-14 14:33 ` [PATCH v2 " Peter Lafreniere
0 siblings, 2 replies; 4+ messages in thread
From: Peter Lafreniere @ 2023-04-07 14:20 UTC (permalink / raw)
To: linux-hams; +Cc: Peter Lafreniere, netdev
There's no need to loop until the end of the list if we have a result.
Device callsigns are unique, so there can only be one dev returned from
ax25_addr_ax25dev(). If not, there would be inconsistencies based on
order of insertion, and refcount leaks.
Same reasoning for ax25_get_route() as above.
Signed-off-by: Peter Lafreniere <peter@n8pjl.ca>
---
net/ax25/ax25_dev.c | 4 +++-
net/ax25/ax25_route.c | 3 +++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c
index c5462486dbca..8186faea6b0d 100644
--- a/net/ax25/ax25_dev.c
+++ b/net/ax25/ax25_dev.c
@@ -34,11 +34,13 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
ax25_dev *ax25_dev, *res = NULL;
spin_lock_bh(&ax25_dev_lock);
- for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
+ for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next) {
if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
res = ax25_dev;
ax25_dev_hold(ax25_dev);
+ break;
}
+ }
spin_unlock_bh(&ax25_dev_lock);
return res;
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index b7c4d656a94b..ed2cab200589 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -364,6 +364,9 @@ ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
ax25_def_rt = ax25_rt;
}
+
+ if (ax25_spe_rt != NULL)
+ break;
}
ax25_rt = ax25_def_rt;
--
2.40.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] ax25: exit linked-list searches earlier
2023-04-07 14:20 [PATCH net-next] ax25: exit linked-list searches earlier Peter Lafreniere
@ 2023-04-07 15:14 ` Dan Carpenter
2023-04-14 14:33 ` [PATCH v2 " Peter Lafreniere
1 sibling, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2023-04-07 15:14 UTC (permalink / raw)
To: Peter Lafreniere; +Cc: linux-hams, netdev
On Fri, Apr 07, 2023 at 10:20:42AM -0400, Peter Lafreniere wrote:
> diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
> index b7c4d656a94b..ed2cab200589 100644
> --- a/net/ax25/ax25_route.c
> +++ b/net/ax25/ax25_route.c
> @@ -364,6 +364,9 @@ ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
> if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
> ax25_def_rt = ax25_rt;
> }
> +
> + if (ax25_spe_rt != NULL)
> + break;
Better to just return directly.
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index b7c4d656a94b..a8a3ab8c92f6 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -364,13 +364,12 @@ ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
ax25_def_rt = ax25_rt;
}
- }
- ax25_rt = ax25_def_rt;
- if (ax25_spe_rt != NULL)
- ax25_rt = ax25_spe_rt;
+ if (ax25_spe_rt)
+ return ax25_spe_rt;
+ }
- return ax25_rt;
+ return ax25_def_rt;
}
/*
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v2 net-next] ax25: exit linked-list searches earlier
2023-04-07 14:20 [PATCH net-next] ax25: exit linked-list searches earlier Peter Lafreniere
2023-04-07 15:14 ` Dan Carpenter
@ 2023-04-14 14:33 ` Peter Lafreniere
2023-04-18 7:15 ` Paolo Abeni
1 sibling, 1 reply; 4+ messages in thread
From: Peter Lafreniere @ 2023-04-14 14:33 UTC (permalink / raw)
To: linux-hams; +Cc: Peter Lafreniere, netdev, error27
There's no need to loop until the end of the list if we have a result.
Device callsigns are unique, so there can only be one dev returned from
ax25_addr_ax25dev(). If not, there would be inconsistencies based on
order of insertion, and refcount leaks.
We follow the same reasoning in ax25_get_route(), and additionally
reorder conditions to skip calling ax25cmp() whenever possible.
Signed-off-by: Peter Lafreniere <peter@n8pjl.ca>
---
v1 -> v2
- Make ax25_get_route() return directly
- Reorder calls to ax25cmp() in ax25_get_route()
- Skip searching for default route once found in ax25_get_route()
net/ax25/ax25_dev.c | 4 +++-
net/ax25/ax25_route.c | 25 +++++++++++++------------
2 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c
index c5462486dbca..8186faea6b0d 100644
--- a/net/ax25/ax25_dev.c
+++ b/net/ax25/ax25_dev.c
@@ -34,11 +34,13 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
ax25_dev *ax25_dev, *res = NULL;
spin_lock_bh(&ax25_dev_lock);
- for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
+ for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next) {
if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
res = ax25_dev;
ax25_dev_hold(ax25_dev);
+ break;
}
+ }
spin_unlock_bh(&ax25_dev_lock);
return res;
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index b7c4d656a94b..ebef46c38e80 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -344,7 +344,6 @@ const struct seq_operations ax25_rt_seqops = {
*/
ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
{
- ax25_route *ax25_spe_rt = NULL;
ax25_route *ax25_def_rt = NULL;
ax25_route *ax25_rt;
@@ -354,23 +353,25 @@ ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
*/
for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
if (dev == NULL) {
- if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
- ax25_spe_rt = ax25_rt;
- if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
+ if (ax25_rt->dev != NULL && ax25cmp(&ax25_rt->callsign, addr) == 0)
+ return ax25_rt;
+
+ if (ax25_def_rt != NULL &&
+ ax25_rt->dev != NULL &&
+ ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
ax25_def_rt = ax25_rt;
} else {
- if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
- ax25_spe_rt = ax25_rt;
- if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
+ if (ax25_rt->dev == dev && ax25cmp(&ax25_rt->callsign, addr) == 0)
+ return ax25_rt;
+
+ if (ax25_def_rt != NULL &&
+ ax25_rt->dev == dev &&
+ ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
ax25_def_rt = ax25_rt;
}
}
- ax25_rt = ax25_def_rt;
- if (ax25_spe_rt != NULL)
- ax25_rt = ax25_spe_rt;
-
- return ax25_rt;
+ return ax25_def_rt;
}
/*
--
2.40.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net-next] ax25: exit linked-list searches earlier
2023-04-14 14:33 ` [PATCH v2 " Peter Lafreniere
@ 2023-04-18 7:15 ` Paolo Abeni
0 siblings, 0 replies; 4+ messages in thread
From: Paolo Abeni @ 2023-04-18 7:15 UTC (permalink / raw)
To: Peter Lafreniere, linux-hams; +Cc: netdev, error27
On Fri, 2023-04-14 at 10:33 -0400, Peter Lafreniere wrote:
> There's no need to loop until the end of the list if we have a result.
>
> Device callsigns are unique, so there can only be one dev returned from
> ax25_addr_ax25dev(). If not, there would be inconsistencies based on
> order of insertion, and refcount leaks.
>
> We follow the same reasoning in ax25_get_route(), and additionally
> reorder conditions to skip calling ax25cmp() whenever possible.
>
> Signed-off-by: Peter Lafreniere <peter@n8pjl.ca>
> ---
> v1 -> v2
> - Make ax25_get_route() return directly
> - Reorder calls to ax25cmp() in ax25_get_route()
> - Skip searching for default route once found in ax25_get_route()
>
> net/ax25/ax25_dev.c | 4 +++-
> net/ax25/ax25_route.c | 25 +++++++++++++------------
> 2 files changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c
> index c5462486dbca..8186faea6b0d 100644
> --- a/net/ax25/ax25_dev.c
> +++ b/net/ax25/ax25_dev.c
> @@ -34,11 +34,13 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
> ax25_dev *ax25_dev, *res = NULL;
>
> spin_lock_bh(&ax25_dev_lock);
> - for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
> + for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next) {
> if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
> res = ax25_dev;
> ax25_dev_hold(ax25_dev);
> + break;
> }
> + }
> spin_unlock_bh(&ax25_dev_lock);
>
> return res;
> diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
> index b7c4d656a94b..ebef46c38e80 100644
> --- a/net/ax25/ax25_route.c
> +++ b/net/ax25/ax25_route.c
> @@ -344,7 +344,6 @@ const struct seq_operations ax25_rt_seqops = {
> */
> ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
> {
> - ax25_route *ax25_spe_rt = NULL;
> ax25_route *ax25_def_rt = NULL;
> ax25_route *ax25_rt;
>
> @@ -354,23 +353,25 @@ ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
> */
> for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
> if (dev == NULL) {
> - if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
> - ax25_spe_rt = ax25_rt;
> - if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
> + if (ax25_rt->dev != NULL && ax25cmp(&ax25_rt->callsign, addr) == 0)
> + return ax25_rt;
> +
> + if (ax25_def_rt != NULL &&
> + ax25_rt->dev != NULL &&
> + ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
> ax25_def_rt = ax25_rt;
> } else {
> - if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
> - ax25_spe_rt = ax25_rt;
> - if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
> + if (ax25_rt->dev == dev && ax25cmp(&ax25_rt->callsign, addr) == 0)
> + return ax25_rt;
> +
> + if (ax25_def_rt != NULL &&
> + ax25_rt->dev == dev &&
> + ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
> ax25_def_rt = ax25_rt;
If I read correctly, multiple routes can legitly match the null
callsign and the above chunk introduces a behavioral change: before the
kernel selected the last of such routes, now the first one.
What about dropping the new condition 'ax25_def_rt != NULL' ?
If so, this patch could target the -net tree - with a suitable fixes
tag.
Thanks!
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-04-18 7:19 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-07 14:20 [PATCH net-next] ax25: exit linked-list searches earlier Peter Lafreniere
2023-04-07 15:14 ` Dan Carpenter
2023-04-14 14:33 ` [PATCH v2 " Peter Lafreniere
2023-04-18 7:15 ` Paolo Abeni
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).