From cd7330c06195d3ff8c7a601bac449b0e8b3f2bec Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sun, 19 Aug 2018 12:22:12 -0700 Subject: 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 Tested-by: Vlad Buslov Cc: Vlad Buslov Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/act_ife.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-) (limited to 'net/sched') diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c index 711ccc4607cc..408584314af3 100644 --- a/net/sched/act_ife.c +++ b/net/sched/act_ife.c @@ -249,10 +249,8 @@ 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; @@ -260,13 +258,9 @@ 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 } @@ -283,10 +277,9 @@ 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); @@ -313,12 +306,16 @@ 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; @@ -326,7 +323,7 @@ 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; } @@ -398,7 +395,6 @@ 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) { @@ -412,11 +408,11 @@ 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; } @@ -481,6 +477,8 @@ 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) @@ -508,9 +506,6 @@ metadata_parse_err: tcf_idr_release(*a, bind); if (ret == ACT_P_CREATED) _tcf_ife_cleanup(*a, bind); - - if (exists) - spin_unlock_bh(&ife->tcf_lock); return err; } @@ -524,20 +519,14 @@ 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_idr_insert(tn, *a); -- cgit v1.2.3