diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 1a39779bdbad..3c103cf9fd0d 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -3076,11 +3076,28 @@ __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type, int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type, void *type_data, bool err_stop, bool rtnl_held) { + bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held; int ok_count; +retry: + if (take_rtnl) + rtnl_lock(); down_read(&block->cb_lock); + /* Need to obtain rtnl lock if block is bound to devs that require it. + * In block bind code cb_lock is obtained while holding rtnl, so we must + * obtain the locks in same order here. + */ + if (!rtnl_held && !take_rtnl && block->lockeddevcnt) { + up_read(&block->cb_lock); + take_rtnl = true; + goto retry; + } + ok_count = __tc_setup_cb_call(block, type, type_data, err_stop); + up_read(&block->cb_lock); + if (take_rtnl) + rtnl_unlock(); return ok_count; } EXPORT_SYMBOL(tc_setup_cb_call); @@ -3095,9 +3112,23 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp, enum tc_setup_type type, void *type_data, bool err_stop, u32 *flags, unsigned int *in_hw_count, bool rtnl_held) { + bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held; int ok_count; +retry: + if (take_rtnl) + rtnl_lock(); down_read(&block->cb_lock); + /* Need to obtain rtnl lock if block is bound to devs that require it. + * In block bind code cb_lock is obtained while holding rtnl, so we must + * obtain the locks in same order here. + */ + if (!rtnl_held && !take_rtnl && block->lockeddevcnt) { + up_read(&block->cb_lock); + take_rtnl = true; + goto retry; + } + /* Make sure all netdevs sharing this block are offload-capable. */ if (block->nooffloaddevcnt && err_stop) { ok_count = -EOPNOTSUPP; @@ -3115,6 +3146,8 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp, ok_count, true); err_unlock: up_read(&block->cb_lock); + if (take_rtnl) + rtnl_unlock(); return ok_count < 0 ? ok_count : 0; } EXPORT_SYMBOL(tc_setup_cb_add); @@ -3131,9 +3164,23 @@ int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp, u32 *new_flags, unsigned int *new_in_hw_count, bool rtnl_held) { + bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held; int ok_count; +retry: + if (take_rtnl) + rtnl_lock(); down_read(&block->cb_lock); + /* Need to obtain rtnl lock if block is bound to devs that require it. + * In block bind code cb_lock is obtained while holding rtnl, so we must + * obtain the locks in same order here. + */ + if (!rtnl_held && !take_rtnl && block->lockeddevcnt) { + up_read(&block->cb_lock); + take_rtnl = true; + goto retry; + } + /* Make sure all netdevs sharing this block are offload-capable. */ if (block->nooffloaddevcnt && err_stop) { ok_count = -EOPNOTSUPP; @@ -3155,6 +3202,8 @@ int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp, new_flags, ok_count, true); err_unlock: up_read(&block->cb_lock); + if (take_rtnl) + rtnl_unlock(); return ok_count < 0 ? ok_count : 0; } EXPORT_SYMBOL(tc_setup_cb_replace); @@ -3167,9 +3216,23 @@ int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp, enum tc_setup_type type, void *type_data, bool err_stop, u32 *flags, unsigned int *in_hw_count, bool rtnl_held) { + bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held; int ok_count; +retry: + if (take_rtnl) + rtnl_lock(); down_read(&block->cb_lock); + /* Need to obtain rtnl lock if block is bound to devs that require it. + * In block bind code cb_lock is obtained while holding rtnl, so we must + * obtain the locks in same order here. + */ + if (!rtnl_held && !take_rtnl && block->lockeddevcnt) { + up_read(&block->cb_lock); + take_rtnl = true; + goto retry; + } + ok_count = __tc_setup_cb_call(block, type, type_data, err_stop); tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags); @@ -3177,6 +3240,8 @@ int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp, tp->ops->hw_del(tp, type_data); up_read(&block->cb_lock); + if (take_rtnl) + rtnl_unlock(); return ok_count < 0 ? ok_count : 0; } EXPORT_SYMBOL(tc_setup_cb_destroy);