diff options
| -rw-r--r-- | include/linux/skbuff.h | 66 | ||||
| -rw-r--r-- | include/linux/socket.h | 5 | ||||
| -rw-r--r-- | net/compat.c | 1 | ||||
| -rw-r--r-- | net/core/datagram.c | 14 | ||||
| -rw-r--r-- | net/core/skbuff.c | 37 | ||||
| -rw-r--r-- | net/ipv4/ip_output.c | 50 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 33 | ||||
| -rw-r--r-- | net/ipv6/ip6_output.c | 49 | ||||
| -rw-r--r-- | net/socket.c | 2 |
9 files changed, 193 insertions, 64 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d3d10556f0fa..1111adefd906 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -686,10 +686,18 @@ enum { * charged to the kernel memory. */ SKBFL_PURE_ZEROCOPY = BIT(2), + + SKBFL_DONT_ORPHAN = BIT(3), + + /* page references are managed by the ubuf_info, so it's safe to + * use frags only up until ubuf_info is released + */ + SKBFL_MANAGED_FRAG_REFS = BIT(4), }; #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG) -#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY) +#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \ + SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS) /* * The callback notifies userspace to release buffers when skb DMA is done in @@ -1773,13 +1781,14 @@ void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg, bool success); -int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, - struct iov_iter *from, size_t length); +int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, + struct sk_buff *skb, struct iov_iter *from, + size_t length); static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len) { - return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len); + return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len); } int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, @@ -1806,6 +1815,11 @@ static inline bool skb_zcopy_pure(const struct sk_buff *skb) return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY; } +static inline bool skb_zcopy_managed(const struct sk_buff *skb) +{ + return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS; +} + static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1, const struct sk_buff *skb2) { @@ -1880,6 +1894,14 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success) } } +void __skb_zcopy_downgrade_managed(struct sk_buff *skb); + +static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) +{ + if (unlikely(skb_zcopy_managed(skb))) + __skb_zcopy_downgrade_managed(skb); +} + static inline void skb_mark_not_on_list(struct sk_buff *skb) { skb->next = NULL; @@ -2528,6 +2550,22 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb) return skb_headlen(skb) + __skb_pagelen(skb); } +static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo, + int i, struct page *page, + int off, int size) +{ + skb_frag_t *frag = &shinfo->frags[i]; + + /* + * Propagate page pfmemalloc to the skb if we can. The problem is + * that not all callers have unique ownership of the page but rely + * on page_is_pfmemalloc doing the right thing(tm). + */ + frag->bv_page = page; + frag->bv_offset = off; + skb_frag_size_set(frag, size); +} + /** * __skb_fill_page_desc - initialise a paged fragment in an skb * @skb: buffer containing fragment to be initialised @@ -2544,17 +2582,7 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb) static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, struct page *page, int off, int size) { - skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; - - /* - * Propagate page pfmemalloc to the skb if we can. The problem is - * that not all callers have unique ownership of the page but rely - * on page_is_pfmemalloc doing the right thing(tm). - */ - frag->bv_page = page; - frag->bv_offset = off; - skb_frag_size_set(frag, size); - + __skb_fill_page_desc_noacc(skb_shinfo(skb), i, page, off, size); page = compound_head(page); if (page_is_pfmemalloc(page)) skb->pfmemalloc = true; @@ -3182,8 +3210,7 @@ static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) { if (likely(!skb_zcopy(skb))) return 0; - if (!skb_zcopy_is_nouarg(skb) && - skb_uarg(skb)->callback == msg_zerocopy_callback) + if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN) return 0; return skb_copy_ubufs(skb, gfp_mask); } @@ -3496,7 +3523,10 @@ static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle) */ static inline void skb_frag_unref(struct sk_buff *skb, int f) { - __skb_frag_unref(&skb_shinfo(skb)->frags[f], skb->pp_recycle); + struct skb_shared_info *shinfo = skb_shinfo(skb); + + if (!skb_zcopy_managed(skb)) + __skb_frag_unref(&shinfo->frags[f], skb->pp_recycle); } /** diff --git a/include/linux/socket.h b/include/linux/socket.h index 17311ad9f9af..3c11ef18a9cf 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -14,6 +14,8 @@ struct file; struct pid; struct cred; struct socket; +struct sock; +struct sk_buff; #define __sockaddr_check_size(size) \ BUILD_BUG_ON(((size) > sizeof(struct __kernel_sockaddr_storage))) @@ -69,6 +71,9 @@ struct msghdr { unsigned int msg_flags; /* flags on received message */ __kernel_size_t msg_controllen; /* ancillary data buffer length */ struct kiocb *msg_iocb; /* ptr to iocb for async requests */ + struct ubuf_info *msg_ubuf; + int (*sg_from_iter)(struct sock *sk, struct sk_buff *skb, + struct iov_iter *from, size_t length); }; struct user_msghdr { diff --git a/net/compat.c b/net/compat.c index 210fc3b4d0d8..6cd2e7683dd0 100644 --- a/net/compat.c +++ b/net/compat.c @@ -80,6 +80,7 @@ int __get_compat_msghdr(struct msghdr *kmsg, return -EMSGSIZE; kmsg->msg_iocb = NULL; + kmsg->msg_ubuf = NULL; *ptr = msg.msg_iov; *len = msg.msg_iovlen; return 0; diff --git a/net/core/datagram.c b/net/core/datagram.c index 50f4faeea76c..ecbc0f471089 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -613,10 +613,16 @@ fault: } EXPORT_SYMBOL(skb_copy_datagram_from_iter); -int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, - struct iov_iter *from, size_t length) +int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, + struct sk_buff *skb, struct iov_iter *from, + size_t length) { - int frag = skb_shinfo(skb)->nr_frags; + int frag; + + if (msg && msg->msg_ubuf && msg->sg_from_iter) + return msg->sg_from_iter(sk, skb, from, length); + + frag = skb_shinfo(skb)->nr_frags; while (length && iov_iter_count(from)) { struct page *pages[MAX_SKB_FRAGS]; @@ -702,7 +708,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) if (skb_copy_datagram_from_iter(skb, 0, from, copy)) return -EFAULT; - return __zerocopy_sg_from_iter(NULL, skb, from, ~0U); + return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U); } EXPORT_SYMBOL(zerocopy_sg_from_iter); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 5b3559cb1d82..cf4107d80bc4 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -666,11 +666,18 @@ static void skb_release_data(struct sk_buff *skb) &shinfo->dataref)) goto exit; - skb_zcopy_clear(skb, true); + if (skb_zcopy(skb)) { + bool skip_unref = shinfo->flags & SKBFL_MANAGED_FRAG_REFS; + + skb_zcopy_clear(skb, true); + if (skip_unref) + goto free_head; + } for (i = 0; i < shinfo->nr_frags; i++) __skb_frag_unref(&shinfo->frags[i], skb->pp_recycle); +free_head: if (shinfo->frag_list) kfree_skb_list(shinfo->frag_list); @@ -895,7 +902,10 @@ EXPORT_SYMBOL(skb_dump); */ void skb_tx_error(struct sk_buff *skb) { - skb_zcopy_clear(skb, true); + if (skb) { + skb_zcopy_downgrade_managed(skb); + skb_zcopy_clear(skb, true); + } } EXPORT_SYMBOL(skb_tx_error); @@ -1193,7 +1203,7 @@ static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size) uarg->len = 1; uarg->bytelen = size; uarg->zerocopy = 1; - uarg->flags = SKBFL_ZEROCOPY_FRAG; + uarg->flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN; refcount_set(&uarg->refcnt, 1); sock_hold(sk); @@ -1212,6 +1222,10 @@ struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, const u32 byte_limit = 1 << 19; /* limit to a few TSO */ u32 bytelen, next; + /* there might be non MSG_ZEROCOPY users */ + if (uarg->callback != msg_zerocopy_callback) + return NULL; + /* realloc only when socket is locked (TCP, UDP cork), * so uarg->len and sk_zckey access is serialized */ @@ -1354,7 +1368,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, if (orig_uarg && uarg != orig_uarg) return -EEXIST; - err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len); + err = __zerocopy_sg_from_iter(msg, sk, skb, &msg->msg_iter, len); if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) { struct sock *save_sk = skb->sk; @@ -1371,6 +1385,16 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, } EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream); +void __skb_zcopy_downgrade_managed(struct sk_buff *skb) +{ + int i; + + skb_shinfo(skb)->flags &= ~SKBFL_MANAGED_FRAG_REFS; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) + skb_frag_ref(skb, i); +} +EXPORT_SYMBOL_GPL(__skb_zcopy_downgrade_managed); + static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig, gfp_t gfp_mask) { @@ -1688,6 +1712,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, BUG_ON(skb_shared(skb)); + skb_zcopy_downgrade_managed(skb); + size = SKB_DATA_ALIGN(size); if (skb_pfmemalloc(skb)) @@ -3484,6 +3510,8 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) int pos = skb_headlen(skb); const int zc_flags = SKBFL_SHARED_FRAG | SKBFL_PURE_ZEROCOPY; + skb_zcopy_downgrade_managed(skb); + skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & zc_flags; skb_zerocopy_clone(skb1, skb, 0); if (len < pos) /* Split line is inside header. */ @@ -3837,6 +3865,7 @@ int skb_append_pagefrags(struct sk_buff *skb, struct page *page, if (skb_can_coalesce(skb, i, page, offset)) { skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); } else if (i < MAX_SKB_FRAGS) { + skb_zcopy_downgrade_managed(skb); get_page(page); skb_fill_page_desc(skb, i, page, offset, size); } else { diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 00b4bf26fd93..df7f9dfbe8be 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -969,7 +969,6 @@ static int __ip_append_data(struct sock *sk, struct inet_sock *inet = inet_sk(sk); struct ubuf_info *uarg = NULL; struct sk_buff *skb; - struct ip_options *opt = cork->opt; int hh_len; int exthdrlen; @@ -977,6 +976,7 @@ static int __ip_append_data(struct sock *sk, int copy; int err; int offset = 0; + bool zc = false; unsigned int maxfraglen, fragheaderlen, maxnonfragsize; int csummode = CHECKSUM_NONE; struct rtable *rt = (struct rtable *)cork->dst; @@ -1017,17 +1017,35 @@ static int __ip_append_data(struct sock *sk, (!exthdrlen || (rt->dst.dev->features & NETIF_F_HW_ESP_TX_CSUM))) csummode = CHECKSUM_PARTIAL; - if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { - uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); - if (!uarg) - return -ENOBUFS; - extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ - if (rt->dst.dev->features & NETIF_F_SG && - csummode == CHECKSUM_PARTIAL) { - paged = true; - } else { - uarg->zerocopy = 0; - skb_zcopy_set(skb, uarg, &extra_uref); + if ((flags & MSG_ZEROCOPY) && length) { + struct msghdr *msg = from; + + if (getfrag == ip_generic_getfrag && msg->msg_ubuf) { + if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb)) + return -EINVAL; + + /* Leave uarg NULL if can't zerocopy, callers should + * be able to handle it. + */ + if ((rt->dst.dev->features & NETIF_F_SG) && + csummode == CHECKSUM_PARTIAL) { + paged = true; + zc = true; + uarg = msg->msg_ubuf; + } + } else if (sock_flag(sk, SOCK_ZEROCOPY)) { + uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); + if (!uarg) + return -ENOBUFS; + extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ + if (rt->dst.dev->features & NETIF_F_SG && + csummode == CHECKSUM_PARTIAL) { + paged = true; + zc = true; + } else { + uarg->zerocopy = 0; + skb_zcopy_set(skb, uarg, &extra_uref); + } } } @@ -1091,9 +1109,12 @@ alloc_new_skb: (fraglen + alloc_extra < SKB_MAX_ALLOC || !(rt->dst.dev->features & NETIF_F_SG))) alloclen = fraglen; - else { + else if (!zc) { alloclen = min_t(int, fraglen, MAX_HEADER); pagedlen = fraglen - alloclen; + } else { + alloclen = fragheaderlen + transhdrlen; + pagedlen = datalen - transhdrlen; } alloclen += alloc_extra; @@ -1188,13 +1209,14 @@ alloc_new_skb: err = -EFAULT; goto error; } - } else if (!uarg || !uarg->zerocopy) { + } else if (!zc) { int i = skb_shinfo(skb)->nr_frags; err = -ENOMEM; if (!sk_page_frag_refill(sk, pfrag)) goto error; + skb_zcopy_downgrade_managed(skb); if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { err = -EMSGSIZE; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 028513d3e2a2..fdb80b9608fe 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1202,17 +1202,23 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) flags = msg->msg_flags; - if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) { + if ((flags & MSG_ZEROCOPY) && size) { skb = tcp_write_queue_tail(sk); - uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb)); - if (!uarg) { - err = -ENOBUFS; - goto out_err; - } - zc = sk->sk_route_caps & NETIF_F_SG; - if (!zc) - uarg->zerocopy = 0; + if (msg->msg_ubuf) { + uarg = msg->msg_ubuf; + net_zcopy_get(uarg); + zc = sk->sk_route_caps & NETIF_F_SG; + } else if (sock_flag(sk, SOCK_ZEROCOPY)) { + uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb)); + if (!uarg) { + err = -ENOBUFS; + goto out_err; + } + zc = sk->sk_route_caps & NETIF_F_SG; + if (!zc) + uarg->zerocopy = 0; + } } if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) && @@ -1335,8 +1341,13 @@ new_segment: copy = min_t(int, copy, pfrag->size - pfrag->offset); - if (tcp_downgrade_zcopy_pure(sk, skb) || - !sk_wmem_schedule(sk, copy)) + if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) { + if (tcp_downgrade_zcopy_pure(sk, skb)) + goto wait_for_space; + skb_zcopy_downgrade_managed(skb); + } + + if (!sk_wmem_schedule(sk, copy)) goto wait_for_space; err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 77e3f5970ce4..897ca4f9b791 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1464,6 +1464,7 @@ static int __ip6_append_data(struct sock *sk, int copy; int err; int offset = 0; + bool zc = false; u32 tskey = 0; struct rt6_info *rt = (struct rt6_info *)cork->dst; struct ipv6_txoptions *opt = v6_cork->opt; @@ -1541,17 +1542,35 @@ emsgsize: rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) csummode = CHECKSUM_PARTIAL; - if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { - uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); - if (!uarg) - return -ENOBUFS; - extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ - if (rt->dst.dev->features & NETIF_F_SG && - csummode == CHECKSUM_PARTIAL) { - paged = true; - } else { - uarg->zerocopy = 0; - skb_zcopy_set(skb, uarg, &extra_uref); + if ((flags & MSG_ZEROCOPY) && length) { + struct msghdr *msg = from; + + if (getfrag == ip_generic_getfrag && msg->msg_ubuf) { + if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb)) + return -EINVAL; + + /* Leave uarg NULL if can't zerocopy, callers should + * be able to handle it. + */ + if ((rt->dst.dev->features & NETIF_F_SG) && + csummode == CHECKSUM_PARTIAL) { + paged = true; + zc = true; + uarg = msg->msg_ubuf; + } + } else if (sock_flag(sk, SOCK_ZEROCOPY)) { + uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); + if (!uarg) + return -ENOBUFS; + extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ + if (rt->dst.dev->features & NETIF_F_SG && + csummode == CHECKSUM_PARTIAL) { + paged = true; + zc = true; + } else { + uarg->zerocopy = 0; + skb_zcopy_set(skb, uarg, &extra_uref); + } } } @@ -1630,9 +1649,12 @@ alloc_new_skb: (fraglen + alloc_extra < SKB_MAX_ALLOC || !(rt->dst.dev->features & NETIF_F_SG))) alloclen = fraglen; - else { + else if (!zc) { alloclen = min_t(int, fraglen, MAX_HEADER); pagedlen = fraglen - alloclen; + } else { + alloclen = fragheaderlen + transhdrlen; + pagedlen = datalen - transhdrlen; } alloclen += alloc_extra; @@ -1742,13 +1764,14 @@ alloc_new_skb: err = -EFAULT; goto error; } - } else if (!uarg || !uarg->zerocopy) { + } else if (!zc) { int i = skb_shinfo(skb)->nr_frags; err = -ENOMEM; if (!sk_page_frag_refill(sk, pfrag)) goto error; + skb_zcopy_downgrade_managed(skb); if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { err = -EMSGSIZE; diff --git a/net/socket.c b/net/socket.c index 96300cdc0625..82af3882b876 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2106,6 +2106,7 @@ int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags, msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_namelen = 0; + msg.msg_ubuf = NULL; if (addr) { err = move_addr_to_kernel(addr, addr_len, &address); if (err < 0) @@ -2405,6 +2406,7 @@ int __copy_msghdr_from_user(struct msghdr *kmsg, return -EMSGSIZE; kmsg->msg_iocb = NULL; + kmsg->msg_ubuf = NULL; *uiov = msg.msg_iov; *nsegs = msg.msg_iovlen; return 0; |