diff options
| author | Vlad Buslov <vladbu@mellanox.com> | 2019-02-11 10:55:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-02-12 13:41:32 -0500 |
| commit | 2cbfab07c69657a5a60323f86143f4ce8a829fa9 (patch) | |
| tree | 0c7fcdb0554f25b1cfe3e1afdfc7b5620978b561 /net | |
| parent | 91052fa1c657d83d570a3ab0ca0ddf87713b5cc8 (diff) | |
net: sched: refactor tc_ctl_chain() to use block->lock
In order to remove dependency on rtnl lock, modify chain API to use
block->lock to protect chain from concurrent modification. Rearrange
tc_ctl_chain() code to call tcf_chain_hold() while holding block->lock to
prevent concurrent chain removal.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/cls_api.c | 36 |
1 files changed, 25 insertions, 11 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 2ebf8e53038a..b5db0f79db14 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -2255,6 +2255,8 @@ replay: err = -EINVAL; goto errout_block; } + + mutex_lock(&block->lock); chain = tcf_chain_lookup(block, chain_index); if (n->nlmsg_type == RTM_NEWCHAIN) { if (chain) { @@ -2266,41 +2268,49 @@ replay: } else { NL_SET_ERR_MSG(extack, "Filter chain already exists"); err = -EEXIST; - goto errout_block; + goto errout_block_locked; } } else { if (!(n->nlmsg_flags & NLM_F_CREATE)) { NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain"); err = -ENOENT; - goto errout_block; + goto errout_block_locked; } chain = tcf_chain_create(block, chain_index); if (!chain) { NL_SET_ERR_MSG(extack, "Failed to create filter chain"); err = -ENOMEM; - goto errout_block; + goto errout_block_locked; } } } else { if (!chain || tcf_chain_held_by_acts_only(chain)) { NL_SET_ERR_MSG(extack, "Cannot find specified filter chain"); err = -EINVAL; - goto errout_block; + goto errout_block_locked; } tcf_chain_hold(chain); } + if (n->nlmsg_type == RTM_NEWCHAIN) { + /* Modifying chain requires holding parent block lock. In case + * the chain was successfully added, take a reference to the + * chain. This ensures that an empty chain does not disappear at + * the end of this function. + */ + tcf_chain_hold(chain); + chain->explicitly_created = true; + } + mutex_unlock(&block->lock); + switch (n->nlmsg_type) { case RTM_NEWCHAIN: err = tc_chain_tmplt_add(chain, net, tca, extack); - if (err) + if (err) { + tcf_chain_put_explicitly_created(chain); goto errout; - /* In case the chain was successfully added, take a reference - * to the chain. This ensures that an empty chain - * does not disappear at the end of this function. - */ - tcf_chain_hold(chain); - chain->explicitly_created = true; + } + tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL, RTM_NEWCHAIN, false); break; @@ -2334,6 +2344,10 @@ errout_block: /* Replay the request. */ goto replay; return err; + +errout_block_locked: + mutex_unlock(&block->lock); + goto errout_block; } /* called with RTNL */ |