From patchwork Fri Jan 25 14:27:07 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [RFC,7/7] net: return a *const* struct page from skb_frag_page. Date: Fri, 25 Jan 2013 04:27:07 -0000 From: Alex Bligh X-Patchwork-Id: 215747 Message-Id: <1359124027-1170-8-git-send-email-alex@alex.org.uk> To: netdev Cc: Stefano Stabellini , Ian Campbell , Alex Bligh , "Trond Myklebust" , Mel Gorman From: Mel Gorman This attempts to catch bare uses of get/put_page (which take a non-const struct page) on skb paged fragments. Add __skb_frag_page for those callers which really need a non-const reference to the page. Signed-off-by: Ian Campbell citrix.com> Cc: "David S. Miller" davemloft.net> Cc: Eric Dumazet gmail.com> Cc: "Michał Mirosław" rere.qmqm.pl> Cc: netdev vger.kernel.org Signed-off-by: Alex Bligh --- drivers/infiniband/ulp/ipoib/ipoib_cm.c | 4 ++-- drivers/infiniband/ulp/ipoib/ipoib_ib.c | 2 +- drivers/net/ethernet/broadcom/bnx2.c | 2 +- drivers/net/ethernet/intel/e1000/e1000_main.c | 2 +- drivers/net/ethernet/jme.c | 2 +- drivers/net/ethernet/sun/cassini.c | 2 +- drivers/net/ethernet/sun/niu.c | 2 +- drivers/net/xen-netback/netback.c | 2 +- drivers/net/xen-netfront.c | 4 ++-- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 2 +- drivers/scsi/cxgbi/libcxgbi.c | 2 +- drivers/scsi/fcoe/fcoe_transport.c | 2 +- include/linux/skbuff.h | 30 +++++++++++++++++-------- net/core/skbuff.c | 6 +++-- net/core/user_dma.c | 2 +- net/ipv4/tcp.c | 2 +- 16 files changed, 41 insertions(+), 27 deletions(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index 014504d..2373cb89 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -538,8 +538,8 @@ static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space, if (length == 0) { /* don't need this page */ - skb_fill_page_desc(toskb, i, skb_frag_page(frag), - 0, PAGE_SIZE); + skb_fill_page_desc(toskb, i, __skb_frag_page(frag), + 0, PAGE_SIZE);/* XXX */ --skb_shinfo(skb)->nr_frags; } else { size = min(length, (unsigned) PAGE_SIZE); diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c index 4115be5..26e4bd7 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c @@ -328,7 +328,7 @@ static int ipoib_dma_map_tx(struct ib_device *ca, for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) { const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; mapping[i + off] = ib_dma_map_page(ca, - skb_frag_page(frag), + __skb_frag_page(frag), frag->page_offset, skb_frag_size(frag), DMA_TO_DEVICE); if (unlikely(ib_dma_mapping_error(ca, mapping[i + off]))) diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c index 965c723..2927700 100644 --- a/drivers/net/ethernet/broadcom/bnx2.c +++ b/drivers/net/ethernet/broadcom/bnx2.c @@ -2930,7 +2930,7 @@ bnx2_reuse_rx_skb_pages(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, shinfo = skb_shinfo(skb); shinfo->nr_frags--; - page = skb_frag_page(&shinfo->frags[shinfo->nr_frags]); + page = __skb_frag_page(&shinfo->frags[shinfo->nr_frags]); __skb_frag_set_page(&shinfo->frags[shinfo->nr_frags], NULL); cons_rx_pg->page = page; diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index cf480b5..c1d6f18 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -2916,7 +2916,7 @@ static int e1000_tx_map(struct e1000_adapter *adapter, * Avoid terminating buffers within evenly-aligned * dwords. */ bufend = (unsigned long) - page_to_phys(skb_frag_page(frag)); + page_to_phys(__skb_frag_page(frag)); bufend += offset + size - 1; if (unlikely(adapter->pcix_82544 && !(bufend & 4) && diff --git a/drivers/net/ethernet/jme.c b/drivers/net/ethernet/jme.c index 76b8457..833b322 100644 --- a/drivers/net/ethernet/jme.c +++ b/drivers/net/ethernet/jme.c @@ -2036,7 +2036,7 @@ jme_map_tx_skb(struct jme_adapter *jme, struct sk_buff *skb, int idx) ctxbi = txbi + ((idx + i + 2) & (mask)); jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi, - skb_frag_page(frag), + __skb_frag_page(frag), frag->page_offset, skb_frag_size(frag), hidma); } diff --git a/drivers/net/ethernet/sun/cassini.c b/drivers/net/ethernet/sun/cassini.c index fd40988..61f6e93 100644 --- a/drivers/net/ethernet/sun/cassini.c +++ b/drivers/net/ethernet/sun/cassini.c @@ -2841,7 +2841,7 @@ static inline int cas_xmit_tx_ringN(struct cas *cp, int ring, ctrl, 0); entry = TX_DESC_NEXT(ring, entry); - addr = cas_page_map(skb_frag_page(fragp)); + addr = cas_page_map(__skb_frag_page(fragp)); memcpy(tx_tiny_buf(cp, ring, entry), addr + fragp->page_offset + len - tabort, tabort); diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c index 73c7081..85fe5c2 100644 --- a/drivers/net/ethernet/sun/niu.c +++ b/drivers/net/ethernet/sun/niu.c @@ -6730,7 +6730,7 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb, const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; len = skb_frag_size(frag); - mapping = np->ops->map_page(np->device, skb_frag_page(frag), + mapping = np->ops->map_page(np->device, __skb_frag_page(frag), frag->page_offset, len, DMA_TO_DEVICE); diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 15e332d..43ff39b 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -525,7 +525,7 @@ static int netbk_gop_skb(struct sk_buff *skb, for (i = 0; i < nr_frags; i++) { netbk_gop_frag_copy(vif, skb, npo, - skb_frag_page(&skb_shinfo(skb)->frags[i]), + __skb_frag_page(&skb_shinfo(skb)->frags[i]), skb_frag_size(&skb_shinfo(skb)->frags[i]), skb_shinfo(skb)->frags[i].page_offset, &head); diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 226faab..6d3d36b 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -770,7 +770,7 @@ static RING_IDX xennet_fill_frags(struct netfront_info *np, skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; __skb_fill_page_desc(skb, nr_frags, - skb_frag_page(nfrag), + __skb_frag_page(nfrag), rx->offset, rx->status); skb->data_len += rx->status; @@ -954,7 +954,7 @@ err: } NETFRONT_SKB_CB(skb)->page = - skb_frag_page(&skb_shinfo(skb)->frags[0]); + __skb_frag_page(&skb_shinfo(skb)->frags[0]); NETFRONT_SKB_CB(skb)->offset = rx->offset; len = rx->status; diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index 8c6156a..cd45c0f 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -322,7 +322,7 @@ static int bnx2fc_xmit(struct fc_lport *lport, struct fc_frame *fp) return -ENOMEM; } frag = &skb_shinfo(skb)->frags[skb_shinfo(skb)->nr_frags - 1]; - cp = kmap_atomic(skb_frag_page(frag), KM_SKB_DATA_SOFTIRQ) + cp = kmap_atomic(__skb_frag_page(frag), KM_SKB_DATA_SOFTIRQ) + frag->page_offset; } else { cp = (struct fcoe_crc_eof *)skb_put(skb, tlen); diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c index c10f74a..eba623a 100644 --- a/drivers/scsi/cxgbi/libcxgbi.c +++ b/drivers/scsi/cxgbi/libcxgbi.c @@ -1949,7 +1949,7 @@ int cxgbi_conn_init_pdu(struct iscsi_task *task, unsigned int offset, /* data fits in the skb's headroom */ for (i = 0; i < tdata->nr_frags; i++, frag++) { - char *src = kmap_atomic(frag->page, + char *src = kmap_atomic(__skb_frag_page(frag), KM_SOFTIRQ0); memcpy(dst, src+frag->offset, frag->size); diff --git a/drivers/scsi/fcoe/fcoe_transport.c b/drivers/scsi/fcoe/fcoe_transport.c index bd97b22..3cc35f3 100644 --- a/drivers/scsi/fcoe/fcoe_transport.c +++ b/drivers/scsi/fcoe/fcoe_transport.c @@ -210,7 +210,7 @@ u32 fcoe_fc_crc(struct fc_frame *fp) while (len > 0) { clen = min(len, PAGE_SIZE - (off & ~PAGE_MASK)); data = kmap_atomic( - skb_frag_page(frag) + (off >> PAGE_SHIFT), + __skb_frag_page(frag) + (off >> PAGE_SHIFT), KM_SKB_DATA_SOFTIRQ); crc = crc32(crc, data + (off & ~PAGE_MASK), clen); kunmap_atomic(data, KM_SKB_DATA_SOFTIRQ); diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 698e4c1..4adf576 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1728,12 +1728,24 @@ static inline void netdev_free_page(struct net_device *dev, struct page *page) } /** - * skb_frag_page - retrieve the page refered to by a paged fragment + * __skb_frag_page - retrieve the page refered to by a paged fragment * @frag: the paged fragment * - * Returns the &struct page associated with @frag. + * Returns the &struct page associated with @frag. Where possible you + * should use skb_frag_page() which returns a const &struct page. */ -static inline struct page *skb_frag_page(const skb_frag_t *frag) +static inline struct page *__skb_frag_page(const skb_frag_t *frag) +{ + return frag->page.p; +} + +/** + * __skb_frag_page - retrieve the page refered to by a paged fragment + * @frag: the paged fragment + * + * Returns the &struct page associated with @frag as a const. + */ +static inline const struct page *skb_frag_page(const skb_frag_t *frag) { return frag->page.p; } @@ -1753,7 +1765,7 @@ static inline void __skb_frag_ref(skb_frag_t *frag) skb_frag_destructor_ref(frag->page.destructor); return; } - get_page(skb_frag_page(frag)); + get_page(__skb_frag_page(frag)); } /** @@ -1780,7 +1792,7 @@ static inline void __skb_frag_unref(skb_frag_t *frag) skb_frag_destructor_unref(frag->page.destructor); return; } - put_page(skb_frag_page(frag)); + put_page(__skb_frag_page(frag)); } /** @@ -1856,7 +1868,7 @@ static inline void *skb_frag_kmap_atomic(const skb_frag_t *frag) local_bh_disable(); #endif - return kmap_atomic(skb_frag_page(frag), KM_SKB_DATA_SOFTIRQ); + return kmap_atomic(__skb_frag_page(frag), KM_SKB_DATA_SOFTIRQ); } static inline void skb_frag_kunmap_atomic(void *vaddr) @@ -1875,7 +1887,7 @@ static inline void skb_frag_kunmap_atomic(void *vaddr) */ static inline void *skb_frag_kmap(const skb_frag_t *frag) { - return kmap(skb_frag_page(frag)); + return kmap(__skb_frag_page(frag)); } /** @@ -1886,7 +1898,7 @@ static inline void *skb_frag_kmap(const skb_frag_t *frag) */ static inline void skb_frag_kunmap(const skb_frag_t *frag) { - kunmap(skb_frag_page(frag)); + kunmap(__skb_frag_page(frag)); } /** @@ -1905,7 +1917,7 @@ static inline dma_addr_t skb_frag_dma_map(struct device *dev, size_t offset, size_t size, enum dma_data_direction dir) { - return dma_map_page(dev, skb_frag_page(frag), + return dma_map_page(dev, __skb_frag_page(frag), frag->page_offset + offset, size, dir); } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 047f38f..5f20a48 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1653,7 +1653,8 @@ static int __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; - if (__splice_segment(skb_frag_page(f), + /* XXX */ + if (__splice_segment(__skb_frag_page(f), f->page_offset, skb_frag_size(f), offset, len, skb, spd, 0, sk, pipe)) return 1; @@ -2965,7 +2966,8 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) if (copy > len) copy = len; - sg_set_page(&sg[elt], skb_frag_page(frag), copy, + /* XXX */ + sg_set_page(&sg[elt], __skb_frag_page(frag), copy, frag->page_offset+offset-start); elt++; if (!(len -= copy)) diff --git a/net/core/user_dma.c b/net/core/user_dma.c index 1b5fefd..1c51151 100644 --- a/net/core/user_dma.c +++ b/net/core/user_dma.c @@ -79,7 +79,7 @@ int dma_skb_copy_datagram_iovec(struct dma_chan *chan, end = start + skb_frag_size(frag); copy = end - offset; if (copy > 0) { - struct page *page = skb_frag_page(frag); + struct page *page = __skb_frag_page(frag); /* XXX */ if (copy > len) copy = len; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 56ef323..28afcf7 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3037,7 +3037,7 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, for (i = 0; i < shi->nr_frags; ++i) { const struct skb_frag_struct *f = &shi->frags[i]; - struct page *page = skb_frag_page(f); + struct page *page = __skb_frag_page(f); /* XXX */ sg_set_page(&sg, page, skb_frag_size(f), f->page_offset); if (crypto_hash_update(desc, &sg, skb_frag_size(f))) return 1;