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authorCong Wang <xiyou.wangcong@gmail.com>2018-08-19 12:22:12 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-15 09:42:56 +0200
commitc892575c97268007a56c2b94df8651e9d08c650b (patch)
treec46646161500fbdb86aa13c631504d48f4c599ed /net/sched
parentdfb2b5b8ed4ffdc23c473e44c6e154297c7bc552 (diff)
act_ife: move tcfa_lock down to where necessary
[ Upstream commit 4e407ff5cd67ec76eeeea1deec227b7982dc7f66 ] The only time we need to take tcfa_lock is when adding a new metainfo to an existing ife->metalist. We don't need to take tcfa_lock so early and so broadly in tcf_ife_init(). This means we can always take ife_mod_lock first, avoid the reverse locking ordering warning as reported by Vlad. Reported-by: Vlad Buslov <vladbu@mellanox.com> Tested-by: Vlad Buslov <vladbu@mellanox.com> Cc: Vlad Buslov <vladbu@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/act_ife.c37
1 files changed, 13 insertions, 24 deletions
diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index df90ca9cd95b..dfcd4e8ba9c0 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -267,10 +267,8 @@ static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
}
/* called when adding new meta information
- * under ife->tcf_lock for existing action
*/
-static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
- void *val, int len, bool exists)
+static int load_metaops_and_vet(u32 metaid, void *val, int len)
{
struct tcf_meta_ops *ops = find_ife_oplist(metaid);
int ret = 0;
@@ -278,13 +276,9 @@ static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
if (!ops) {
ret = -ENOENT;
#ifdef CONFIG_MODULES
- if (exists)
- spin_unlock_bh(&ife->tcf_lock);
rtnl_unlock();
request_module("ifemeta%u", metaid);
rtnl_lock();
- if (exists)
- spin_lock_bh(&ife->tcf_lock);
ops = find_ife_oplist(metaid);
#endif
}
@@ -301,10 +295,9 @@ static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
}
/* called when adding new meta information
- * under ife->tcf_lock for existing action
*/
static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
- int len, bool atomic)
+ int len, bool atomic, bool exists)
{
struct tcf_meta_info *mi = NULL;
struct tcf_meta_ops *ops = find_ife_oplist(metaid);
@@ -331,12 +324,16 @@ static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
}
}
+ if (exists)
+ spin_lock_bh(&ife->tcf_lock);
list_add_tail(&mi->metalist, &ife->metalist);
+ if (exists)
+ spin_unlock_bh(&ife->tcf_lock);
return ret;
}
-static int use_all_metadata(struct tcf_ife_info *ife)
+static int use_all_metadata(struct tcf_ife_info *ife, bool exists)
{
struct tcf_meta_ops *o;
int rc = 0;
@@ -344,7 +341,7 @@ static int use_all_metadata(struct tcf_ife_info *ife)
read_lock(&ife_mod_lock);
list_for_each_entry(o, &ifeoplist, list) {
- rc = add_metainfo(ife, o->metaid, NULL, 0, true);
+ rc = add_metainfo(ife, o->metaid, NULL, 0, true, exists);
if (rc == 0)
installed += 1;
}
@@ -416,7 +413,6 @@ static void tcf_ife_cleanup(struct tc_action *a, int bind)
spin_unlock_bh(&ife->tcf_lock);
}
-/* under ife->tcf_lock for existing action */
static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
bool exists)
{
@@ -430,11 +426,11 @@ static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
val = nla_data(tb[i]);
len = nla_len(tb[i]);
- rc = load_metaops_and_vet(ife, i, val, len, exists);
+ rc = load_metaops_and_vet(i, val, len);
if (rc != 0)
return rc;
- rc = add_metainfo(ife, i, val, len, exists);
+ rc = add_metainfo(ife, i, val, len, false, exists);
if (rc)
return rc;
}
@@ -510,6 +506,8 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
if (exists)
spin_lock_bh(&ife->tcf_lock);
ife->tcf_action = parm->action;
+ if (exists)
+ spin_unlock_bh(&ife->tcf_lock);
if (parm->flags & IFE_ENCODE) {
if (daddr)
@@ -537,9 +535,6 @@ metadata_parse_err:
tcf_hash_release(*a, bind);
if (ret == ACT_P_CREATED)
_tcf_ife_cleanup(*a, bind);
-
- if (exists)
- spin_unlock_bh(&ife->tcf_lock);
return err;
}
@@ -553,20 +548,14 @@ metadata_parse_err:
* as we can. You better have at least one else we are
* going to bail out
*/
- err = use_all_metadata(ife);
+ err = use_all_metadata(ife, exists);
if (err) {
if (ret == ACT_P_CREATED)
_tcf_ife_cleanup(*a, bind);
-
- if (exists)
- spin_unlock_bh(&ife->tcf_lock);
return err;
}
}
- if (exists)
- spin_unlock_bh(&ife->tcf_lock);
-
if (ret == ACT_P_CREATED)
tcf_hash_insert(tn, *a);