xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: sched: refactor tp insert/delete for concurrent execution

Browse Source 
Implement unique insertion function to atomically attach tcf_proto to chain
after verifying that no other tcf proto with specified priority exists.
Implement delete function that verifies that tp is actually empty before
deleting it. Use these functions to refactor cls API to account for
concurrent tp and rule update instead of relying on rtnl lock. Add new
'deleting' flag to tcf proto. Use it to restart search when iterating over
tp's on chain to prevent accessing potentially inval tp->next pointer.

Extend tcf proto with spinlock that is intended to be used to protect its
data from concurrent modification instead of relying on rtnl mutex. Use it
to protect 'deleting' flag. Add lockdep macros to validate that lock is
held when accessing protected fields.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vlad Buslov
2019-02-11 10:55:41 +02:00
committed by David S. Miller
parent fe2923afc1
commit 8b64678e0a
2 changed files with 170 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
include/net/sch_generic.h
View File

@@ -322,6 +322,11 @@ struct tcf_proto {
void *data;
const struct tcf_proto_ops *ops;
struct tcf_chain *chain;
/* Lock protects tcf_proto shared state and can be used by unlocked
* classifiers to protect their private data.
*/
spinlock_t lock;
bool deleting;
refcount_t refcnt;
struct rcu_head rcu;
};
@@ -382,16 +387,29 @@ static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
{
return lockdep_is_held(&chain->filter_chain_lock);
}
static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
{
return lockdep_is_held(&tp->lock);
}
#else
static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
{
return true;
}
static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
{
return true;
}
#endif /* #ifdef CONFIG_PROVE_LOCKING */
#define tcf_chain_dereference(p, chain) \
rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
#define tcf_proto_dereference(p, tp) \
rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
{
if (*flags & TCA_CLS_FLAGS_IN_HW)