Re: [PATCH] Revert netlink ABI change to gnet_stats_basic
From: Eric Dumazet
Date: Sun Aug 16 2009 - 15:37:26 EST
Michael Spang a écrit :
> On Sun, Aug 16, 2009 at 8:33 AM, Eric Dumazet<eric.dumazet@xxxxxxxxx> wrote:
>> What exactly broke after patch was pushed ?
>
> The libnl library refuses to initialize with 2.6.30 with pre-2.6.30
> headers. With 2.6.30 I get
>
> $ libnl-1.1/src/nl-qdisc-dump brief
> Unable to retrieve qdisc cache
>
> whereas previously I would get
>
> $ libnl-1.1/src/nl-qdisc-dump brief
> htb qdisc dev eth0 handle 01: parent root r2q 10000 default :02
>
> It works fine if I use the headers from 2.6.30, but then I don't
> believe it would work with older kernels.
>
OK, then we are stuck to use a separate definition for user land
and kernel land, or risk various side effects, like performance hit
and security risk.
Thanks a lot Michael
[PATCH] net: restore gnet_stats_basic to previous definition
In 5e140dfc1fe87eae27846f193086724806b33c7d "net: reorder struct Qdisc
for better SMP performance" the definition of struct gnet_stats_basic
changed incompatibly, as copies of this struct are shipped to
userland via netlink.
Restoring old behavior is not welcome, for performance reason.
Fix is to use a private structure for kernel, and
teach gnet_stats_copy_basic() to convert from kernel to user land,
using legacy structure (struct gnet_stats_basic)
Based on a report and initial patch from Michael Spang.
Reported-by: Michael Spang <mspang@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
---
include/linux/gen_stats.h | 5 +++++
include/net/act_api.h | 2 +-
include/net/gen_stats.h | 10 +++++-----
include/net/netfilter/xt_rateest.h | 2 +-
include/net/sch_generic.h | 2 +-
net/core/gen_estimator.c | 12 ++++++------
net/core/gen_stats.c | 11 ++++++++---
net/netfilter/xt_RATEEST.c | 2 +-
net/sched/sch_atm.c | 2 +-
net/sched/sch_cbq.c | 2 +-
net/sched/sch_drr.c | 2 +-
net/sched/sch_hfsc.c | 2 +-
net/sched/sch_htb.c | 2 +-
13 files changed, 33 insertions(+), 23 deletions(-)
diff --git a/include/linux/gen_stats.h b/include/linux/gen_stats.h
index 0ffa41d..710e901 100644
--- a/include/linux/gen_stats.h
+++ b/include/linux/gen_stats.h
@@ -22,6 +22,11 @@ struct gnet_stats_basic
{
__u64 bytes;
__u32 packets;
+};
+struct gnet_stats_basic_packed
+{
+ __u64 bytes;
+ __u32 packets;
} __attribute__ ((packed));
/**
diff --git a/include/net/act_api.h b/include/net/act_api.h
index 565eed8..c05fd71 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -16,7 +16,7 @@ struct tcf_common {
u32 tcfc_capab;
int tcfc_action;
struct tcf_t tcfc_tm;
- struct gnet_stats_basic tcfc_bstats;
+ struct gnet_stats_basic_packed tcfc_bstats;
struct gnet_stats_queue tcfc_qstats;
struct gnet_stats_rate_est tcfc_rate_est;
spinlock_t tcfc_lock;
diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h
index d136b52..c148855 100644
--- a/include/net/gen_stats.h
+++ b/include/net/gen_stats.h
@@ -28,7 +28,7 @@ extern int gnet_stats_start_copy_compat(struct sk_buff *skb, int type,
spinlock_t *lock, struct gnet_dump *d);
extern int gnet_stats_copy_basic(struct gnet_dump *d,
- struct gnet_stats_basic *b);
+ struct gnet_stats_basic_packed *b);
extern int gnet_stats_copy_rate_est(struct gnet_dump *d,
struct gnet_stats_rate_est *r);
extern int gnet_stats_copy_queue(struct gnet_dump *d,
@@ -37,14 +37,14 @@ extern int gnet_stats_copy_app(struct gnet_dump *d, void *st, int len);
extern int gnet_stats_finish_copy(struct gnet_dump *d);
-extern int gen_new_estimator(struct gnet_stats_basic *bstats,
+extern int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est,
spinlock_t *stats_lock, struct nlattr *opt);
-extern void gen_kill_estimator(struct gnet_stats_basic *bstats,
+extern void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est);
-extern int gen_replace_estimator(struct gnet_stats_basic *bstats,
+extern int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est,
spinlock_t *stats_lock, struct nlattr *opt);
-extern bool gen_estimator_active(const struct gnet_stats_basic *bstats,
+extern bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,
const struct gnet_stats_rate_est *rate_est);
#endif
diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h
index 65d594d..ddbf37e 100644
--- a/include/net/netfilter/xt_rateest.h
+++ b/include/net/netfilter/xt_rateest.h
@@ -8,7 +8,7 @@ struct xt_rateest {
spinlock_t lock;
struct gnet_estimator params;
struct gnet_stats_rate_est rstats;
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
};
extern struct xt_rateest *xt_rateest_lookup(const char *name);
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 964ffa0..5482e95 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -72,7 +72,7 @@ struct Qdisc
*/
unsigned long state;
struct sk_buff_head q;
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
};
diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 78e5bfc..493775f 100644
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -81,7 +81,7 @@
struct gen_estimator
{
struct list_head list;
- struct gnet_stats_basic *bstats;
+ struct gnet_stats_basic_packed *bstats;
struct gnet_stats_rate_est *rate_est;
spinlock_t *stats_lock;
int ewma_log;
@@ -165,7 +165,7 @@ static void gen_add_node(struct gen_estimator *est)
}
static
-struct gen_estimator *gen_find_node(const struct gnet_stats_basic *bstats,
+struct gen_estimator *gen_find_node(const struct gnet_stats_basic_packed *bstats,
const struct gnet_stats_rate_est *rate_est)
{
struct rb_node *p = est_root.rb_node;
@@ -202,7 +202,7 @@ struct gen_estimator *gen_find_node(const struct gnet_stats_basic *bstats,
*
* NOTE: Called under rtnl_mutex
*/
-int gen_new_estimator(struct gnet_stats_basic *bstats,
+int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est,
spinlock_t *stats_lock,
struct nlattr *opt)
@@ -262,7 +262,7 @@ static void __gen_kill_estimator(struct rcu_head *head)
*
* NOTE: Called under rtnl_mutex
*/
-void gen_kill_estimator(struct gnet_stats_basic *bstats,
+void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est)
{
struct gen_estimator *e;
@@ -292,7 +292,7 @@ EXPORT_SYMBOL(gen_kill_estimator);
*
* Returns 0 on success or a negative error code.
*/
-int gen_replace_estimator(struct gnet_stats_basic *bstats,
+int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
struct gnet_stats_rate_est *rate_est,
spinlock_t *stats_lock, struct nlattr *opt)
{
@@ -308,7 +308,7 @@ EXPORT_SYMBOL(gen_replace_estimator);
*
* Returns true if estimator is active, and false if not.
*/
-bool gen_estimator_active(const struct gnet_stats_basic *bstats,
+bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,
const struct gnet_stats_rate_est *rate_est)
{
ASSERT_RTNL();
diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
index c3d0ffe..8569310 100644
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -106,16 +106,21 @@ gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
* if the room in the socket buffer was not sufficient.
*/
int
-gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic *b)
+gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
{
if (d->compat_tc_stats) {
d->tc_stats.bytes = b->bytes;
d->tc_stats.packets = b->packets;
}
- if (d->tail)
- return gnet_stats_copy(d, TCA_STATS_BASIC, b, sizeof(*b));
+ if (d->tail) {
+ struct gnet_stats_basic sb;
+ memset(&sb, 0, sizeof(sb));
+ sb.bytes = b->bytes;
+ sb.packets = b->packets;
+ return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
+ }
return 0;
}
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index 43f5676..d80b819 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -74,7 +74,7 @@ static unsigned int
xt_rateest_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
const struct xt_rateest_target_info *info = par->targinfo;
- struct gnet_stats_basic *stats = &info->est->bstats;
+ struct gnet_stats_basic_packed *stats = &info->est->bstats;
spin_lock_bh(&info->est->lock);
stats->bytes += skb->len;
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 2a8b83a..ab82f14 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -49,7 +49,7 @@ struct atm_flow_data {
struct socket *sock; /* for closing */
u32 classid; /* x:y type ID */
int ref; /* reference count */
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
struct atm_flow_data *next;
struct atm_flow_data *excess; /* flow for excess traffic;
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 23a1676..d5798e1 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -128,7 +128,7 @@ struct cbq_class
long avgidle;
long deficit; /* Saved deficit for WRR */
psched_time_t penalized;
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
struct gnet_stats_rate_est rate_est;
struct tc_cbq_xstats xstats;
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 7597fe1..12b2fb0 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -22,7 +22,7 @@ struct drr_class {
unsigned int refcnt;
unsigned int filter_cnt;
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
struct gnet_stats_rate_est rate_est;
struct list_head alist;
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 362c281..dad0144 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -116,7 +116,7 @@ struct hfsc_class
struct Qdisc_class_common cl_common;
unsigned int refcnt; /* usage count */
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
struct gnet_stats_rate_est rate_est;
unsigned int level; /* class level in hierarchy */
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 88cd026..ec4d463 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -74,7 +74,7 @@ enum htb_cmode {
struct htb_class {
struct Qdisc_class_common common;
/* general class parameters */
- struct gnet_stats_basic bstats;
+ struct gnet_stats_basic_packed bstats;
struct gnet_stats_queue qstats;
struct gnet_stats_rate_est rate_est;
struct tc_htb_xstats xstats; /* our special stats */
--
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