From 9538ebce88ffa074202d592d468521995cb1e714 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Fri, 7 Apr 2023 17:14:50 +0300 Subject: net: dsa: add trace points for FDB/MDB operations DSA performs non-trivial housekeeping of unicast and multicast addresses on shared (CPU and DSA) ports, and puts a bit of pressure on higher layers, requiring them to behave correctly (remove these addresses exactly as many times as they were added). Otherwise, either addresses linger around forever, or DSA returns -ENOENT complaining that entries that were already deleted must be deleted again. To aid debugging, introduce some trace points specifically for FDB and MDB - that's where some of the bugs still are right now. Some bugs I have seen were also due to race conditions, see: - 630fd4822af2 ("net: dsa: flush switchdev workqueue on bridge join error path") - a2614140dc0f ("net: dsa: mv88e6xxx: flush switchdev FDB workqueue before removing VLAN") so it would be good to not disturb the timing too much, hence the choice to use trace points vs regular dev_dbg(). I've had these for some time on my computer in a less polished form, and they've proven useful. What I found most useful was to enable CONFIG_BOOTTIME_TRACING, add "trace_event=dsa" to the kernel cmdline, and run "cat /sys/kernel/debug/tracing/trace". This is to debug more complex environments with network managers started by the init system, things like that. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- net/dsa/switch.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 50 insertions(+), 11 deletions(-) (limited to 'net/dsa/switch.c') diff --git a/net/dsa/switch.c b/net/dsa/switch.c index d5bc4bb7310d..ff1b5d980e37 100644 --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -18,6 +18,7 @@ #include "slave.h" #include "switch.h" #include "tag_8021q.h" +#include "trace.h" static unsigned int dsa_switch_fastest_ageing_time(struct dsa_switch *ds, unsigned int ageing_time) @@ -164,14 +165,20 @@ static int dsa_port_do_mdb_add(struct dsa_port *dp, int err = 0; /* No need to bother with refcounting for user ports */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_mdb_add(ds, port, mdb, db); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_mdb_add(ds, port, mdb, db); + trace_dsa_mdb_add_hw(dp, mdb->addr, mdb->vid, &db, err); + + return err; + } mutex_lock(&dp->addr_lists_lock); a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid, db); if (a) { refcount_inc(&a->refcount); + trace_dsa_mdb_add_bump(dp, mdb->addr, mdb->vid, &db, + &a->refcount); goto out; } @@ -182,6 +189,7 @@ static int dsa_port_do_mdb_add(struct dsa_port *dp, } err = ds->ops->port_mdb_add(ds, port, mdb, db); + trace_dsa_mdb_add_hw(dp, mdb->addr, mdb->vid, &db, err); if (err) { kfree(a); goto out; @@ -209,21 +217,30 @@ static int dsa_port_do_mdb_del(struct dsa_port *dp, int err = 0; /* No need to bother with refcounting for user ports */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_mdb_del(ds, port, mdb, db); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_mdb_del(ds, port, mdb, db); + trace_dsa_mdb_del_hw(dp, mdb->addr, mdb->vid, &db, err); + + return err; + } mutex_lock(&dp->addr_lists_lock); a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid, db); if (!a) { + trace_dsa_mdb_del_not_found(dp, mdb->addr, mdb->vid, &db); err = -ENOENT; goto out; } - if (!refcount_dec_and_test(&a->refcount)) + if (!refcount_dec_and_test(&a->refcount)) { + trace_dsa_mdb_del_drop(dp, mdb->addr, mdb->vid, &db, + &a->refcount); goto out; + } err = ds->ops->port_mdb_del(ds, port, mdb, db); + trace_dsa_mdb_del_hw(dp, mdb->addr, mdb->vid, &db, err); if (err) { refcount_set(&a->refcount, 1); goto out; @@ -247,14 +264,19 @@ static int dsa_port_do_fdb_add(struct dsa_port *dp, const unsigned char *addr, int err = 0; /* No need to bother with refcounting for user ports */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_fdb_add(ds, port, addr, vid, db); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_fdb_add(ds, port, addr, vid, db); + trace_dsa_fdb_add_hw(dp, addr, vid, &db, err); + + return err; + } mutex_lock(&dp->addr_lists_lock); a = dsa_mac_addr_find(&dp->fdbs, addr, vid, db); if (a) { refcount_inc(&a->refcount); + trace_dsa_fdb_add_bump(dp, addr, vid, &db, &a->refcount); goto out; } @@ -265,6 +287,7 @@ static int dsa_port_do_fdb_add(struct dsa_port *dp, const unsigned char *addr, } err = ds->ops->port_fdb_add(ds, port, addr, vid, db); + trace_dsa_fdb_add_hw(dp, addr, vid, &db, err); if (err) { kfree(a); goto out; @@ -291,21 +314,29 @@ static int dsa_port_do_fdb_del(struct dsa_port *dp, const unsigned char *addr, int err = 0; /* No need to bother with refcounting for user ports */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_fdb_del(ds, port, addr, vid, db); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_fdb_del(ds, port, addr, vid, db); + trace_dsa_fdb_del_hw(dp, addr, vid, &db, err); + + return err; + } mutex_lock(&dp->addr_lists_lock); a = dsa_mac_addr_find(&dp->fdbs, addr, vid, db); if (!a) { + trace_dsa_fdb_del_not_found(dp, addr, vid, &db); err = -ENOENT; goto out; } - if (!refcount_dec_and_test(&a->refcount)) + if (!refcount_dec_and_test(&a->refcount)) { + trace_dsa_fdb_del_drop(dp, addr, vid, &db, &a->refcount); goto out; + } err = ds->ops->port_fdb_del(ds, port, addr, vid, db); + trace_dsa_fdb_del_hw(dp, addr, vid, &db, err); if (err) { refcount_set(&a->refcount, 1); goto out; @@ -332,6 +363,8 @@ static int dsa_switch_do_lag_fdb_add(struct dsa_switch *ds, struct dsa_lag *lag, a = dsa_mac_addr_find(&lag->fdbs, addr, vid, db); if (a) { refcount_inc(&a->refcount); + trace_dsa_lag_fdb_add_bump(lag->dev, addr, vid, &db, + &a->refcount); goto out; } @@ -342,6 +375,7 @@ static int dsa_switch_do_lag_fdb_add(struct dsa_switch *ds, struct dsa_lag *lag, } err = ds->ops->lag_fdb_add(ds, *lag, addr, vid, db); + trace_dsa_lag_fdb_add_hw(lag->dev, addr, vid, &db, err); if (err) { kfree(a); goto out; @@ -370,14 +404,19 @@ static int dsa_switch_do_lag_fdb_del(struct dsa_switch *ds, struct dsa_lag *lag, a = dsa_mac_addr_find(&lag->fdbs, addr, vid, db); if (!a) { + trace_dsa_lag_fdb_del_not_found(lag->dev, addr, vid, &db); err = -ENOENT; goto out; } - if (!refcount_dec_and_test(&a->refcount)) + if (!refcount_dec_and_test(&a->refcount)) { + trace_dsa_lag_fdb_del_drop(lag->dev, addr, vid, &db, + &a->refcount); goto out; + } err = ds->ops->lag_fdb_del(ds, *lag, addr, vid, db); + trace_dsa_lag_fdb_del_hw(lag->dev, addr, vid, &db, err); if (err) { refcount_set(&a->refcount, 1); goto out; -- cgit v1.2.3 From 02020bd70fa6abcb1c2a8525ce7c1500dd4f44a8 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Fri, 7 Apr 2023 17:14:51 +0300 Subject: net: dsa: add trace points for VLAN operations These are not as critical as the FDB/MDB trace points (I'm not aware of outstanding VLAN related bugs), but maybe they are useful to somebody, either debugging something or simply trying to learn more. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- net/dsa/switch.c | 24 ++++++++--- net/dsa/trace.h | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 137 insertions(+), 5 deletions(-) (limited to 'net/dsa/switch.c') diff --git a/net/dsa/switch.c b/net/dsa/switch.c index ff1b5d980e37..8c9a9f94b756 100644 --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -695,8 +695,12 @@ static int dsa_port_do_vlan_add(struct dsa_port *dp, int err = 0; /* No need to bother with refcounting for user ports. */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_vlan_add(ds, port, vlan, extack); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_vlan_add(ds, port, vlan, extack); + trace_dsa_vlan_add_hw(dp, vlan, err); + + return err; + } /* No need to propagate on shared ports the existing VLANs that were * re-notified after just the flags have changed. This would cause a @@ -711,6 +715,7 @@ static int dsa_port_do_vlan_add(struct dsa_port *dp, v = dsa_vlan_find(&dp->vlans, vlan); if (v) { refcount_inc(&v->refcount); + trace_dsa_vlan_add_bump(dp, vlan, &v->refcount); goto out; } @@ -721,6 +726,7 @@ static int dsa_port_do_vlan_add(struct dsa_port *dp, } err = ds->ops->port_vlan_add(ds, port, vlan, extack); + trace_dsa_vlan_add_hw(dp, vlan, err); if (err) { kfree(v); goto out; @@ -745,21 +751,29 @@ static int dsa_port_do_vlan_del(struct dsa_port *dp, int err = 0; /* No need to bother with refcounting for user ports */ - if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) - return ds->ops->port_vlan_del(ds, port, vlan); + if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) { + err = ds->ops->port_vlan_del(ds, port, vlan); + trace_dsa_vlan_del_hw(dp, vlan, err); + + return err; + } mutex_lock(&dp->vlans_lock); v = dsa_vlan_find(&dp->vlans, vlan); if (!v) { + trace_dsa_vlan_del_not_found(dp, vlan); err = -ENOENT; goto out; } - if (!refcount_dec_and_test(&v->refcount)) + if (!refcount_dec_and_test(&v->refcount)) { + trace_dsa_vlan_del_drop(dp, vlan, &v->refcount); goto out; + } err = ds->ops->port_vlan_del(ds, port, vlan); + trace_dsa_vlan_del_hw(dp, vlan, err); if (err) { refcount_set(&v->refcount, 1); goto out; diff --git a/net/dsa/trace.h b/net/dsa/trace.h index 42c8bbc7d472..567f29a39707 100644 --- a/net/dsa/trace.h +++ b/net/dsa/trace.h @@ -9,7 +9,9 @@ #define _NET_DSA_TRACE_H #include +#include #include +#include #include #include @@ -318,6 +320,122 @@ TRACE_EVENT(dsa_lag_fdb_del_not_found, __get_str(dev), __entry->addr, __entry->vid, __entry->db_buf) ); +DECLARE_EVENT_CLASS(dsa_vlan_op_hw, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + + TP_ARGS(dp, vlan, err), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + __field(u16, flags) + __field(bool, changed) + __field(int, err) + ), + + TP_fast_assign( + __assign_str(dev, dev_name(dp->ds->dev)); + __assign_str(kind, dsa_port_kind(dp)); + __entry->port = dp->index; + __entry->vid = vlan->vid; + __entry->flags = vlan->flags; + __entry->changed = vlan->changed; + __entry->err = err; + ), + + TP_printk("%s %s port %d vid %u%s%s%s", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid, + __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "", + __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "", + __entry->changed ? " (changed)" : "") +); + +DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_add_hw, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + TP_ARGS(dp, vlan, err)); + +DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_del_hw, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + TP_ARGS(dp, vlan, err)); + +DECLARE_EVENT_CLASS(dsa_vlan_op_refcount, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + + TP_ARGS(dp, vlan, refcount), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + __field(u16, flags) + __field(bool, changed) + __field(unsigned int, refcount) + ), + + TP_fast_assign( + __assign_str(dev, dev_name(dp->ds->dev)); + __assign_str(kind, dsa_port_kind(dp)); + __entry->port = dp->index; + __entry->vid = vlan->vid; + __entry->flags = vlan->flags; + __entry->changed = vlan->changed; + __entry->refcount = refcount_read(refcount); + ), + + TP_printk("%s %s port %d vid %u%s%s%s refcount %u", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid, + __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "", + __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "", + __entry->changed ? " (changed)" : "", __entry->refcount) +); + +DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_add_bump, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + TP_ARGS(dp, vlan, refcount)); + +DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_del_drop, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + TP_ARGS(dp, vlan, refcount)); + +TRACE_EVENT(dsa_vlan_del_not_found, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan), + + TP_ARGS(dp, vlan), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + ), + + TP_fast_assign( + __assign_str(dev, dev_name(dp->ds->dev)); + __assign_str(kind, dsa_port_kind(dp)); + __entry->port = dp->index; + __entry->vid = vlan->vid; + ), + + TP_printk("%s %s port %d vid %u", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid) +); + #endif /* _NET_DSA_TRACE_H */ /* We don't want to use include/trace/events */ -- cgit v1.2.3