From 8b21e2307f2601fd3baaddb3e22f1a25e6719695 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 12 Sep 2014 20:09:49 -0700 Subject: [PATCH] net: sched: rcu'ify cls_rsvp Signed-off-by: John Fastabend Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/cls_rsvp.h | 160 ++++++++++++++++++++++++------------------- 1 file changed, 90 insertions(+), 70 deletions(-) diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h index 1020e233a5d6..b044c208b133 100644 --- a/net/sched/cls_rsvp.h +++ b/net/sched/cls_rsvp.h @@ -70,31 +70,34 @@ struct rsvp_head { u32 tmap[256/32]; u32 hgenerator; u8 tgenerator; - struct rsvp_session *ht[256]; + struct rsvp_session __rcu *ht[256]; + struct rcu_head rcu; }; struct rsvp_session { - struct rsvp_session *next; - __be32 dst[RSVP_DST_LEN]; - struct tc_rsvp_gpi dpi; - u8 protocol; - u8 tunnelid; + struct rsvp_session __rcu *next; + __be32 dst[RSVP_DST_LEN]; + struct tc_rsvp_gpi dpi; + u8 protocol; + u8 tunnelid; /* 16 (src,sport) hash slots, and one wildcard source slot */ - struct rsvp_filter *ht[16 + 1]; + struct rsvp_filter __rcu *ht[16 + 1]; + struct rcu_head rcu; }; struct rsvp_filter { - struct rsvp_filter *next; - __be32 src[RSVP_DST_LEN]; - struct tc_rsvp_gpi spi; - u8 tunnelhdr; + struct rsvp_filter __rcu *next; + __be32 src[RSVP_DST_LEN]; + struct tc_rsvp_gpi spi; + u8 tunnelhdr; - struct tcf_result res; - struct tcf_exts exts; + struct tcf_result res; + struct tcf_exts exts; - u32 handle; - struct rsvp_session *sess; + u32 handle; + struct rsvp_session *sess; + struct rcu_head rcu; }; static inline unsigned int hash_dst(__be32 *dst, u8 protocol, u8 tunnelid) @@ -128,7 +131,7 @@ static inline unsigned int hash_src(__be32 *src) static int rsvp_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res) { - struct rsvp_session **sht = ((struct rsvp_head *)tp->root)->ht; + struct rsvp_head *head = rcu_dereference_bh(tp->root); struct rsvp_session *s; struct rsvp_filter *f; unsigned int h1, h2; @@ -169,7 +172,8 @@ restart: h1 = hash_dst(dst, protocol, tunnelid); h2 = hash_src(src); - for (s = sht[h1]; s; s = s->next) { + for (s = rcu_dereference_bh(head->ht[h1]); s; + s = rcu_dereference_bh(s->next)) { if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN - 1] && protocol == s->protocol && !(s->dpi.mask & @@ -181,7 +185,8 @@ restart: #endif tunnelid == s->tunnelid) { - for (f = s->ht[h2]; f; f = f->next) { + for (f = rcu_dereference_bh(s->ht[h2]); f; + f = rcu_dereference_bh(f->next)) { if (src[RSVP_DST_LEN-1] == f->src[RSVP_DST_LEN - 1] && !(f->spi.mask & (*(u32 *)(xprt + f->spi.offset) ^ f->spi.key)) #if RSVP_DST_LEN == 4 @@ -205,7 +210,8 @@ matched: } /* And wildcard bucket... */ - for (f = s->ht[16]; f; f = f->next) { + for (f = rcu_dereference_bh(s->ht[16]); f; + f = rcu_dereference_bh(f->next)) { *res = f->res; RSVP_APPLY_RESULT(); goto matched; @@ -218,7 +224,7 @@ matched: static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle) { - struct rsvp_session **sht = ((struct rsvp_head *)tp->root)->ht; + struct rsvp_head *head = rtnl_dereference(tp->root); struct rsvp_session *s; struct rsvp_filter *f; unsigned int h1 = handle & 0xFF; @@ -227,8 +233,10 @@ static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle) if (h2 > 16) return 0; - for (s = sht[h1]; s; s = s->next) { - for (f = s->ht[h2]; f; f = f->next) { + for (s = rtnl_dereference(head->ht[h1]); s; + s = rtnl_dereference(s->next)) { + for (f = rtnl_dereference(s->ht[h2]); f; + f = rtnl_dereference(f->next)) { if (f->handle == handle) return (unsigned long)f; } @@ -246,7 +254,7 @@ static int rsvp_init(struct tcf_proto *tp) data = kzalloc(sizeof(struct rsvp_head), GFP_KERNEL); if (data) { - tp->root = data; + rcu_assign_pointer(tp->root, data); return 0; } return -ENOBUFS; @@ -257,53 +265,54 @@ rsvp_delete_filter(struct tcf_proto *tp, struct rsvp_filter *f) { tcf_unbind_filter(tp, &f->res); tcf_exts_destroy(tp, &f->exts); - kfree(f); + kfree_rcu(f, rcu); } static void rsvp_destroy(struct tcf_proto *tp) { - struct rsvp_head *data = xchg(&tp->root, NULL); - struct rsvp_session **sht; + struct rsvp_head *data = rtnl_dereference(tp->root); int h1, h2; if (data == NULL) return; - sht = data->ht; + RCU_INIT_POINTER(tp->root, NULL); for (h1 = 0; h1 < 256; h1++) { struct rsvp_session *s; - while ((s = sht[h1]) != NULL) { - sht[h1] = s->next; + while ((s = rtnl_dereference(data->ht[h1])) != NULL) { + RCU_INIT_POINTER(data->ht[h1], s->next); for (h2 = 0; h2 <= 16; h2++) { struct rsvp_filter *f; - while ((f = s->ht[h2]) != NULL) { - s->ht[h2] = f->next; + while ((f = rtnl_dereference(s->ht[h2])) != NULL) { + rcu_assign_pointer(s->ht[h2], f->next); rsvp_delete_filter(tp, f); } } - kfree(s); + kfree_rcu(s, rcu); } } - kfree(data); + kfree_rcu(data, rcu); } static int rsvp_delete(struct tcf_proto *tp, unsigned long arg) { - struct rsvp_filter **fp, *f = (struct rsvp_filter *)arg; + struct rsvp_head *head = rtnl_dereference(tp->root); + struct rsvp_filter *nfp, *f = (struct rsvp_filter *)arg; + struct rsvp_filter __rcu **fp; unsigned int h = f->handle; - struct rsvp_session **sp; - struct rsvp_session *s = f->sess; + struct rsvp_session __rcu **sp; + struct rsvp_session *nsp, *s = f->sess; int i; - for (fp = &s->ht[(h >> 8) & 0xFF]; *fp; fp = &(*fp)->next) { - if (*fp == f) { - tcf_tree_lock(tp); - *fp = f->next; - tcf_tree_unlock(tp); + fp = &s->ht[(h >> 8) & 0xFF]; + for (nfp = rtnl_dereference(*fp); nfp; + fp = &nfp->next, nfp = rtnl_dereference(*fp)) { + if (nfp == f) { + RCU_INIT_POINTER(*fp, f->next); rsvp_delete_filter(tp, f); /* Strip tree */ @@ -313,14 +322,12 @@ static int rsvp_delete(struct tcf_proto *tp, unsigned long arg) return 0; /* OK, session has no flows */ - for (sp = &((struct rsvp_head *)tp->root)->ht[h & 0xFF]; - *sp; sp = &(*sp)->next) { - if (*sp == s) { - tcf_tree_lock(tp); - *sp = s->next; - tcf_tree_unlock(tp); - - kfree(s); + sp = &head->ht[h & 0xFF]; + for (nsp = rtnl_dereference(*sp); nsp; + sp = &nsp->next, nsp = rtnl_dereference(*sp)) { + if (nsp == s) { + RCU_INIT_POINTER(*sp, s->next); + kfree_rcu(s, rcu); return 0; } } @@ -333,7 +340,7 @@ static int rsvp_delete(struct tcf_proto *tp, unsigned long arg) static unsigned int gen_handle(struct tcf_proto *tp, unsigned salt) { - struct rsvp_head *data = tp->root; + struct rsvp_head *data = rtnl_dereference(tp->root); int i = 0xFFFF; while (i-- > 0) { @@ -361,7 +368,7 @@ static int tunnel_bts(struct rsvp_head *data) static void tunnel_recycle(struct rsvp_head *data) { - struct rsvp_session **sht = data->ht; + struct rsvp_session __rcu **sht = data->ht; u32 tmap[256/32]; int h1, h2; @@ -369,11 +376,13 @@ static void tunnel_recycle(struct rsvp_head *data) for (h1 = 0; h1 < 256; h1++) { struct rsvp_session *s; - for (s = sht[h1]; s; s = s->next) { + for (s = rtnl_dereference(sht[h1]); s; + s = rtnl_dereference(s->next)) { for (h2 = 0; h2 <= 16; h2++) { struct rsvp_filter *f; - for (f = s->ht[h2]; f; f = f->next) { + for (f = rtnl_dereference(s->ht[h2]); f; + f = rtnl_dereference(f->next)) { if (f->tunnelhdr == 0) continue; data->tgenerator = f->res.classid; @@ -417,9 +426,11 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb, struct nlattr **tca, unsigned long *arg, bool ovr) { - struct rsvp_head *data = tp->root; - struct rsvp_filter *f, **fp; - struct rsvp_session *s, **sp; + struct rsvp_head *data = rtnl_dereference(tp->root); + struct rsvp_filter *f, *nfp; + struct rsvp_filter __rcu **fp; + struct rsvp_session *nsp, *s; + struct rsvp_session __rcu **sp; struct tc_rsvp_pinfo *pinfo = NULL; struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_RSVP_MAX + 1]; @@ -499,7 +510,9 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb, goto errout; } - for (sp = &data->ht[h1]; (s = *sp) != NULL; sp = &s->next) { + for (sp = &data->ht[h1]; + (s = rtnl_dereference(*sp)) != NULL; + sp = &s->next) { if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN-1] && pinfo && pinfo->protocol == s->protocol && memcmp(&pinfo->dpi, &s->dpi, sizeof(s->dpi)) == 0 && @@ -521,12 +534,16 @@ insert: tcf_exts_change(tp, &f->exts, &e); - for (fp = &s->ht[h2]; *fp; fp = &(*fp)->next) - if (((*fp)->spi.mask & f->spi.mask) != f->spi.mask) + fp = &s->ht[h2]; + for (nfp = rtnl_dereference(*fp); nfp; + fp = &nfp->next, nfp = rtnl_dereference(*fp)) { + __u32 mask = nfp->spi.mask & f->spi.mask; + + if (mask != f->spi.mask) break; - f->next = *fp; - wmb(); - *fp = f; + } + RCU_INIT_POINTER(f->next, nfp); + rcu_assign_pointer(*fp, f); *arg = (unsigned long)f; return 0; @@ -546,13 +563,14 @@ insert: s->protocol = pinfo->protocol; s->tunnelid = pinfo->tunnelid; } - for (sp = &data->ht[h1]; *sp; sp = &(*sp)->next) { - if (((*sp)->dpi.mask&s->dpi.mask) != s->dpi.mask) + sp = &data->ht[h1]; + for (nsp = rtnl_dereference(*sp); nsp; + sp = &nsp->next, nsp = rtnl_dereference(*sp)) { + if ((nsp->dpi.mask & s->dpi.mask) != s->dpi.mask) break; } - s->next = *sp; - wmb(); - *sp = s; + RCU_INIT_POINTER(s->next, nsp); + rcu_assign_pointer(*sp, s); goto insert; @@ -565,7 +583,7 @@ errout2: static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg) { - struct rsvp_head *head = tp->root; + struct rsvp_head *head = rtnl_dereference(tp->root); unsigned int h, h1; if (arg->stop) @@ -574,11 +592,13 @@ static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg) for (h = 0; h < 256; h++) { struct rsvp_session *s; - for (s = head->ht[h]; s; s = s->next) { + for (s = rtnl_dereference(head->ht[h]); s; + s = rtnl_dereference(s->next)) { for (h1 = 0; h1 <= 16; h1++) { struct rsvp_filter *f; - for (f = s->ht[h1]; f; f = f->next) { + for (f = rtnl_dereference(s->ht[h1]); f; + f = rtnl_dereference(f->next)) { if (arg->count < arg->skip) { arg->count++; continue; -- 2.30.2