From: Mina Almasry <almasrymina@google.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux.dev, linux-mm@kvack.org,
bpf@vger.kernel.org, linux-wireless@vger.kernel.org,
linux-doc@vger.kernel.org,
bcm-kernel-feedback-list@broadcom.com, imx@lists.linux.dev,
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linux-renesas-soc@vger.kernel.org, linux-omap@vger.kernel.org
Cc: "Mina Almasry" <almasrymina@google.com>,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@kernel.org>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Simon Horman" <horms@kernel.org>,
"Steffen Klassert" <steffen.klassert@secunet.com>,
"Herbert Xu" <herbert@gondor.apana.org.au>,
"Willem de Bruijn" <willemb@google.com>,
"Stanislav Fomichev" <sdf@fomichev.me>,
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"Andrew Lunn" <andrew+netdev@lunn.ch>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Jason Wang" <jasowangio@gmail.com>,
"Eugenio Pérez" <eperezma@redhat.com>,
"Xuan Zhuo" <xuanzhuo@linux.alibaba.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"David Hildenbrand" <david@kernel.org>,
"Lorenzo Stoakes" <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
"Vlastimil Babka" <vbabka@kernel.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Suren Baghdasaryan" <surenb@google.com>,
"Michal Hocko" <mhocko@suse.com>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"John Fastabend" <john.fastabend@gmail.com>,
"Sabrina Dubroca" <sd@queasysnail.net>,
"Johannes Berg" <johannes@sipsolutions.net>,
"Byungchul Park" <byungchul@sk.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Shuah Khan" <skhan@linuxfoundation.org>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Lorenzo Bianconi" <lorenzo@kernel.org>,
"Wen Gu" <guwen@linux.alibaba.com>,
"Philo Lu" <lulie@linux.alibaba.com>,
"Justin Chen" <justin.chen@broadcom.com>,
"Florian Fainelli" <florian.fainelli@broadcom.com>,
"Vikas Gupta" <vikas.gupta@broadcom.com>,
"Michael Chan" <michael.chan@broadcom.com>,
"Pavan Chebbi" <pavan.chebbi@broadcom.com>,
"Doug Berger" <opendmb@gmail.com>,
"Nicolai Buchwitz" <nb@tipi-net.de>,
"Satish Kharat" <satishkh@cisco.com>,
"Wei Fang" <wei.fang@nxp.com>, "Frank Li" <frank.li@nxp.com>,
"Shenwei Wang" <shenwei.wang@nxp.com>,
"Joshua Washington" <joshwash@google.com>,
"Harshitha Ramamurthy" <hramamurthy@google.com>,
"Jijie Shao" <shaojijie@huawei.com>,
"Jian Shen" <shenjian15@huawei.com>,
"Fan Gong" <gongfan1@huawei.com>,
"Tony Nguyen" <anthony.l.nguyen@intel.com>,
"Przemek Kitszel" <przemyslaw.kitszel@intel.com>,
"Marcin Wojtas" <marcin.s.wojtas@gmail.com>,
"Russell King" <linux@armlinux.org.uk>,
"Sunil Goutham" <sgoutham@marvell.com>,
"Geetha sowjanya" <gakula@marvell.com>,
"Ratheesh Kannoth" <rkannoth@marvell.com>,
"Subbaraya Sundeep" <sbhatta@marvell.com>,
"Bharat Bhushan" <bbhushan2@marvell.com>,
"Felix Fietkau" <nbd@nbd.name>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"AngeloGioacchino Del Regno"
<angelogioacchino.delregno@collabora.com>,
"Tariq Toukan" <tariqt@nvidia.com>,
"Saeed Mahameed" <saeedm@nvidia.com>,
"Mark Bloch" <mbloch@nvidia.com>,
"Leon Romanovsky" <leon@kernel.org>,
"Ido Schimmel" <idosch@nvidia.com>,
"Petr Machata" <petrm@nvidia.com>,
"Horatiu Vultur" <horatiu.vultur@microchip.com>,
UNGLinuxDriver@microchip.com,
"Daniel Machon" <daniel.machon@microchip.com>,
"Steen Hegelund" <Steen.Hegelund@microchip.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Wei Liu" <wei.liu@kernel.org>,
"Dexuan Cui" <decui@microsoft.com>,
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"Brett Creeley" <brett.creeley@amd.com>,
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"Larry Chiu" <larry.chiu@realtek.com>,
"Niklas Söderlund" <niklas.soderlund@ragnatech.se>,
"Paul Barker" <paul@pbarker.dev>,
"Masahisa Kojima" <kojima.masahisa@socionext.com>,
"Maxime Chevallier" <maxime.chevallier@bootlin.com>,
"Maxime Coquelin" <mcoquelin.stm32@gmail.com>,
"Alexandre Torgue" <alexandre.torgue@foss.st.com>,
"FUJITA Tomonori" <fujita.tomonori@gmail.com>,
"Siddharth Vadapalli" <s-vadapalli@ti.com>,
"Roger Quadros" <rogerq@kernel.org>,
"MD Danish Anwar" <danishanwar@ti.com>,
"Jiawen Wu" <jiawenwu@trustnetic.com>,
"Mengyuan Lou" <mengyuanlou@net-swift.com>,
"Ronak Doshi" <ronak.doshi@broadcom.com>,
"Ryder Lee" <ryder.lee@mediatek.com>,
"Shayne Chen" <shayne.chen@mediatek.com>,
"Sean Wang" <sean.wang@mediatek.com>,
"Juergen Gross" <jgross@suse.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Oleksandr Tyshchenko" <oleksandr_tyshchenko@epam.com>,
"Jordan Rhee" <jordanrhee@google.com>,
"Ankit Garg" <nktgrg@google.com>,
"Tim Hostetler" <thostet@google.com>,
"Erni Sri Satya Vennela" <ernis@linux.microsoft.com>,
"Eric Joyner" <eric.joyner@amd.com>,
"Mohammad Heib" <mheib@redhat.com>,
"Prabu Thayalan" <prabu.ponrajthayalan@amd.com>,
"Chintan Vankar" <c-vankar@ti.com>,
"Nora Schiffer" <nora.schiffer@ew.tq-group.com>,
"Alexander Sverdlin" <alex@sverdlin.org>,
"Kevin Hao" <haokexin@gmail.com>,
"Karl Mehltretter" <kmehltretter@gmail.com>,
"Aleksandr Loktionov" <aleksandr.loktionov@intel.com>,
"Meghana Malladi" <m-malladi@ti.com>,
"Jacob Keller" <jacob.e.keller@intel.com>,
"StanleyYP Wang" <StanleyYP.Wang@mediatek.com>
Subject: [PATCH net-next v1 4/5] net: remove skb->pp_recycle and consolidate netmem refcounting
Date: Tue, 3 Nov 2026 21:14:23 +0000 [thread overview]
Message-ID: <20261103211424.127627-5-almasrymina@google.com> (raw)
In-Reply-To: <20261103211424.127627-1-almasrymina@google.com>
skb->pp_recycle was introduced in commit 6a5bcd84e886 ("page_pool: Allow
drivers to hint on SKB recycling") when drivers had to explicitly opt in
to page_pool SKB recycling and to avoid touching struct page on the free
path. Today every page_pool-backed netmem carries its own identity via
netmem_is_pp(), making the per-SKB skb->pp_recycle bitfield redundant
and error-prone when SKBs are cloned, split, segmented, shifted, or
coalesced across page_pool and non-page_pool buffers. For non-page_pool
pages, get_page(), put_page(), and skb_free_frag() immediately load the
same first struct page cache line (compound_head, which shares the cache
line with pp_magic), so checking netmem_is_pp() does not add an extra
cache-line load.
Remove skb->pp_recycle and check netmem_is_pp() directly via
napi_pp_get_page() and napi_pp_put_page() inside netmem_inc_ref(),
netmem_dec_ref(), and skb_pp_recycle(), dropping the now-redundant
skb_netmem_ref() and skb_netmem_unref() wrappers. Keep
skb_mark_for_recycle() as a no-op stub to remove its callers in a
separate patch.
Use READ_ONCE() and WRITE_ONCE() on pp_magic and pp because every SKB
fragment ref/unref now checks netmem_is_pp(), and page->pp_magic shares
a struct page union word with folio->lru.next which MM code may
concurrently modify on page-cache folios in TX SKBs.
To close the race where a caller holding only a struct page reference
(such as zerocopy_fill_skb_from_iter(), vmsplice() of a
TCP_ZEROCOPY_RECEIVE mapping, or sk_msg_page_add()) calls
netmem_inc_ref() -> napi_pp_get_page() while the last page_pool holder
concurrently releases its pp_ref_count:
- In page_pool_unref_netmem(), only take the non-RMW read fast path or
reset pp_ref_count to 1 when the page_pool holds the sole page
reference (page_ref_count == 1); when an external page reference
exists, atomically decrement pp_ref_count to 0 and leave it at 0
(restoring it to 1 in __page_pool_put_page() if the external page
reference is dropped before recycling).
- In napi_pp_get_page() and napi_pp_put_page(), use
atomic_long_inc_not_zero() and check page_pool_ref_count() so once
pp_ref_count reaches 0, concurrent callers consistently fall back to
get_page() and put_page().
Verified no fast-path regression with bench_page_pool_simple:
- no-softirq-page_pool01 (fast path): 37 cycles (18.7 ns) baseline vs
36-37 cycles (18.5 ns) patched.
- no-softirq-page_pool02 (ptr_ring): 77-78 cycles (38.9 ns) baseline vs
76-77 cycles (38.4 ns) patched.
- no-softirq-page_pool03 (slow page-allocator path with elevated
page_ref_count): 462-467 cycles (232.2 ns) baseline vs 478-484 cycles
(240.7 ns) patched (+3.4% due to atomic pp_ref_count -> 0 transition
when page_ref_count > 1).
Notes:
- __frame_add_frag() in net/wireless/util.c is switched from get_page()
to skb_frag_ref() (with a MAX_SKB_FRAGS check) so mac80211 A-MSDU
subframe SKBs on page_pool wireless drivers (such as mt76) pair with
skb_release_data().
- net/tls/ record and scatterlist page references in tls_device.c,
tls_device_fallback.c, and tls_main.c are paired with
netmem_inc_ref() and netmem_dec_ref() (with destroy_record() in
tls_tcp_clean_acked() deferred until after dropping ctx->lock).
Caveats:
- For struct page-backed netmems, page_pool membership is identified via
page->pp_magic, which has a pre-existing union aliasing risk with
non-networking struct page fields if a non-page_pool page's union
field matches PP_SIGNATURE (in particular on 32-bit architectures
where POISON_POINTER_DELTA is 0); removing skb->pp_recycle extends
this check from pp_recycle=1 SKBs to all netmem_inc_ref(),
netmem_dec_ref(), and skb_pp_recycle() operations.
- netpoll_zap_completion_queue() has a pre-existing issue where
skb_irq_freeable() does not exclude SKBs holding page_pool memory
before calling __kfree_skb() with hardirqs disabled; TX SKBs carrying
spliced page_pool fragments are subject to the same path.
Signed-off-by: Mina Almasry <almasrymina@google.com>
---
drivers/net/veth.c | 3 +-
drivers/net/virtio_net.c | 8 +-
include/linux/mm.h | 2 +-
include/linux/skbuff.h | 9 +-
include/linux/skbuff_ref.h | 60 +-------
include/net/netmem.h | 39 +++--
include/net/page_pool/helpers.h | 41 +++++-
net/core/gro.c | 9 --
net/core/net_test.c | 251 +++++++++++---------------------
net/core/netmem_priv.h | 23 ++-
net/core/page_pool.c | 8 +-
net/core/skbuff.c | 51 ++-----
net/core/xdp.c | 2 +-
net/ipv4/esp4.c | 11 +-
net/ipv6/esp6.c | 11 +-
net/tls/tls_device.c | 14 +-
net/tls/tls_device_fallback.c | 6 +-
net/tls/tls_main.c | 4 +-
net/wireless/util.c | 31 +++-
net/xfrm/trace_iptfs.h | 6 +-
net/xfrm/xfrm_iptfs.c | 13 +-
21 files changed, 246 insertions(+), 356 deletions(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 3eca92d3dc60d..285958432ea0a 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -27,7 +27,6 @@
#include <linux/ptr_ring.h>
#include <linux/bpf_trace.h>
#include <linux/net_tstamp.h>
-#include <linux/skbuff_ref.h>
#include <net/page_pool/helpers.h>
#define DRV_NAME "veth"
@@ -746,7 +745,7 @@ static void veth_xdp_get(struct xdp_buff *xdp)
struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
int i;
- get_page(virt_to_page(xdp->data));
+ netmem_inc_ref(page_to_netmem(virt_to_page(xdp->data)));
if (likely(!xdp_buff_has_frags(xdp)))
return;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index dd2c41ef6fbe7..3453689bfd341 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2351,9 +2351,6 @@ static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq,
if (unlikely(!nskb))
return NULL;
- if (head_skb->pp_recycle)
- skb_mark_for_recycle(nskb);
-
if (curr_skb == head_skb)
skb_shinfo(curr_skb)->frag_list = nskb;
else
@@ -2371,10 +2368,7 @@ static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq,
offset = buf - page_address(page);
if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
- if (head_skb->pp_recycle)
- page_pool_put_page(rq->page_pool, page, -1, true);
- else
- put_page(page);
+ netmem_dec_ref(page_to_netmem(page));
skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
len, truesize);
} else {
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9f167950926a1..f13d9f6b3ed50 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -5698,7 +5698,7 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status);
#ifdef CONFIG_PAGE_POOL
static inline bool page_pool_page_is_pp(const struct page *page)
{
- return (page->pp_magic & PP_MAGIC_MASK) == PP_SIGNATURE;
+ return (READ_ONCE(page->pp_magic) & PP_MAGIC_MASK) == PP_SIGNATURE;
}
#else
static inline bool page_pool_page_is_pp(const struct page *page)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6787fcf6ac3e4..4eaf4da1f7dad 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -834,8 +834,6 @@ enum skb_tstamp_type {
* @head_frag: skb was allocated from page fragments,
* not allocated by kmalloc() or vmalloc().
* @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
- * @pp_recycle: mark the packet for recycling instead of freeing (implies
- * page_pool support on driver)
* @active_extensions: active extensions (skb_ext_id types)
* @ndisc_nodetype: router type (from link layer)
* @ooo_okay: allow the mapping of a socket to a queue to be changed
@@ -964,8 +962,7 @@ struct sk_buff {
fclone:2,
peeked:1,
head_frag:1,
- pfmemalloc:1,
- pp_recycle:1; /* page_pool recycle indicator */
+ pfmemalloc:1;
#ifdef CONFIG_SKB_EXTENSIONS
__u8 active_extensions;
#endif
@@ -5476,11 +5473,9 @@ static inline struct kcov_common_handle_id skb_get_kcov_handle(struct sk_buff *s
return skb->kcov_handle;
}
+/* Deprecated: page_pool recycling is now determined per netmem. */
static inline void skb_mark_for_recycle(struct sk_buff *skb)
{
-#ifdef CONFIG_PAGE_POOL
- skb->pp_recycle = 1;
-#endif
}
ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter,
diff --git a/include/linux/skbuff_ref.h b/include/linux/skbuff_ref.h
index e94c599ce83d2..b368eb4661ed7 100644
--- a/include/linux/skbuff_ref.h
+++ b/include/linux/skbuff_ref.h
@@ -9,63 +9,21 @@
#include <linux/skbuff.h>
-bool napi_pp_get_page(netmem_ref netmem);
-
-/**
- * skb_netmem_ref - acquire a fragment reference on a netmem
- * @netmem: netmem to reference
- * @recycle: whether page_pool recycling is enabled (e.g. skb->pp_recycle)
- *
- * Acquires pp_ref_count via napi_pp_get_page() if @recycle is true and
- * @netmem belongs to a page_pool; otherwise acquires a non-pp backing
- * reference via netmem_inc_ref(). Counterpart to skb_netmem_unref().
- */
-static __always_inline void skb_netmem_ref(netmem_ref netmem, bool recycle)
-{
-#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_get_page(netmem))
- return;
-#endif
- netmem_inc_ref(netmem);
-}
-
/**
* skb_frag_ref - acquire a reference on a paged fragment of an skb
* @skb: the buffer
* @f: the fragment offset
*
- * Acquires a reference on the @f'th fragment of @skb via skb_netmem_ref()
- * (pp_ref_count if skb->pp_recycle and page_pool-backed, else non-pp
- * backing refcount), skipping managed zerocopy fragments. Counterpart to
- * skb_frag_unref().
+ * Acquires a reference on the @f'th fragment of @skb via netmem_inc_ref()
+ * (pp_ref_count if page_pool-backed, else non-pp backing refcount), skipping
+ * managed zerocopy fragments. Counterpart to skb_frag_unref().
*/
static __always_inline void skb_frag_ref(struct sk_buff *skb, int f)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
if (!skb_zcopy_managed(skb))
- skb_netmem_ref(skb_frag_netmem(&shinfo->frags[f]),
- skb->pp_recycle);
-}
-
-bool napi_pp_put_page(netmem_ref netmem);
-
-/**
- * skb_netmem_unref - release a fragment reference on a netmem
- * @netmem: netmem to unreference
- * @recycle: whether page_pool recycling is enabled (e.g. skb->pp_recycle)
- *
- * Drops pp_ref_count via napi_pp_put_page() if @recycle is true and @netmem
- * belongs to a page_pool; otherwise drops a non-pp backing reference via
- * netmem_dec_ref(). Counterpart to skb_netmem_ref().
- */
-static __always_inline void skb_netmem_unref(netmem_ref netmem, bool recycle)
-{
-#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_put_page(netmem))
- return;
-#endif
- netmem_dec_ref(netmem);
+ netmem_inc_ref(skb_frag_netmem(&shinfo->frags[f]));
}
/**
@@ -73,18 +31,16 @@ static __always_inline void skb_netmem_unref(netmem_ref netmem, bool recycle)
* @skb: the buffer
* @f: the fragment offset
*
- * Drops a reference on the @f'th fragment of @skb via skb_netmem_unref()
- * (pp_ref_count if skb->pp_recycle and page_pool-backed, else non-pp
- * backing refcount), skipping managed zerocopy fragments. Counterpart to
- * skb_frag_ref().
+ * Drops a reference on the @f'th fragment of @skb via netmem_dec_ref()
+ * (pp_ref_count if page_pool-backed, else non-pp backing refcount), skipping
+ * managed zerocopy fragments. Counterpart to skb_frag_ref().
*/
static __always_inline void skb_frag_unref(struct sk_buff *skb, int f)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
if (!skb_zcopy_managed(skb))
- skb_netmem_unref(skb_frag_netmem(&shinfo->frags[f]),
- skb->pp_recycle);
+ netmem_dec_ref(skb_frag_netmem(&shinfo->frags[f]));
}
#endif /* _LINUX_SKBUFF_REF_H */
diff --git a/include/net/netmem.h b/include/net/netmem.h
index fb693bc1702a4..d8ecf0ec34005 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -298,7 +298,7 @@ static inline struct page_pool *__netmem_get_pp(netmem_ref netmem)
static inline struct page_pool *netmem_get_pp(netmem_ref netmem)
{
- return netmem_to_nmdesc(netmem)->pp;
+ return READ_ONCE(netmem_to_nmdesc(netmem)->pp);
}
static inline atomic_long_t *netmem_get_pp_ref_count_ref(netmem_ref netmem)
@@ -412,16 +412,34 @@ static inline bool net_is_devmem_iov(const struct net_iov *niov)
void net_iov_inc_ref(struct net_iov *niov);
void net_iov_dec_ref(struct net_iov *niov);
+#if IS_ENABLED(CONFIG_PAGE_POOL)
+bool napi_pp_get_page(netmem_ref netmem);
+bool napi_pp_put_page(netmem_ref netmem);
+#else
+static inline bool napi_pp_get_page(netmem_ref netmem)
+{
+ return false;
+}
+
+static inline bool napi_pp_put_page(netmem_ref netmem)
+{
+ return false;
+}
+#endif
+
/**
- * netmem_inc_ref - acquire a non-page_pool reference on a netmem
+ * netmem_inc_ref - acquire a reference on a netmem
* @netmem: netmem to reference
*
- * Acquires a non-pp backing reference (page._refcount via get_page() or
- * binding->ref via net_iov_inc_ref()) regardless of page_pool membership.
- * Counterpart to netmem_dec_ref().
+ * Acquires pp_ref_count via napi_pp_get_page() if @netmem belongs to a
+ * page_pool; otherwise acquires a non-pp backing reference (binding->ref via
+ * net_iov_inc_ref() or page._refcount via get_page()). Counterpart to
+ * netmem_dec_ref().
*/
static __always_inline void netmem_inc_ref(netmem_ref netmem)
{
+ if (napi_pp_get_page(netmem))
+ return;
if (netmem_is_net_iov(netmem))
net_iov_inc_ref(netmem_to_net_iov(netmem));
else
@@ -429,15 +447,18 @@ static __always_inline void netmem_inc_ref(netmem_ref netmem)
}
/**
- * netmem_dec_ref - release a non-page_pool reference on a netmem
+ * netmem_dec_ref - release a reference on a netmem
* @netmem: netmem to unreference
*
- * Drops a non-pp backing reference (page._refcount via put_page() or
- * binding->ref via net_iov_dec_ref()) regardless of page_pool membership.
- * Counterpart to netmem_inc_ref().
+ * Drops pp_ref_count via napi_pp_put_page() if @netmem belongs to a
+ * page_pool; otherwise drops a non-pp backing reference (binding->ref via
+ * net_iov_dec_ref() or page._refcount via put_page()). Counterpart to
+ * netmem_inc_ref().
*/
static __always_inline void netmem_dec_ref(netmem_ref netmem)
{
+ if (napi_pp_put_page(netmem))
+ return;
if (netmem_is_net_iov(netmem))
net_iov_dec_ref(netmem_to_net_iov(netmem));
else
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index 28635ce9454e8..af3cb65c30416 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -242,6 +242,11 @@ page_pool_get_dma_dir(const struct page_pool *pool)
return pool->p.dma_dir;
}
+static inline long page_pool_ref_count(netmem_ref netmem)
+{
+ return atomic_long_read(netmem_get_pp_ref_count_ref(netmem));
+}
+
static inline void page_pool_fragment_netmem(netmem_ref netmem, long nr)
{
atomic_long_set(netmem_get_pp_ref_count_ref(netmem), nr);
@@ -270,13 +275,22 @@ static inline void page_pool_fragment_page(struct page *page, long nr)
page_pool_fragment_netmem(page_to_netmem(page), nr);
}
+static inline bool page_pool_netmem_is_exclusively_owned(netmem_ref netmem)
+{
+ if (netmem_is_net_iov(netmem))
+ return true;
+
+ return page_ref_count(__netmem_to_page(netmem)) == 1;
+}
+
static inline long page_pool_unref_netmem(netmem_ref netmem, long nr)
{
atomic_long_t *pp_ref_count = netmem_get_pp_ref_count_ref(netmem);
long ret;
- /* If nr == pp_ref_count then we have cleared all remaining
- * references to the page:
+ /* If nr == pp_ref_count and the page_pool holds the sole page
+ * reference, then we have cleared all remaining references to the
+ * page:
* 1. 'n == 1': no need to actually overwrite it.
* 2. 'n != 1': overwrite it with one, which is the rare case
* for pp_ref_count draining.
@@ -288,8 +302,15 @@ static inline long page_pool_unref_netmem(netmem_ref netmem, long nr)
* handling by ensuring all pages have partitioned into only 1 piece
* initially, and only overwrite it when the page is partitioned into
* more than one piece.
+ *
+ * If an external page reference exists (page_ref_count > 1), a
+ * concurrent napi_pp_get_page() caller holding only a page reference
+ * may attempt atomic_long_inc_not_zero(pp_ref_count), so we must
+ * perform an atomic RMW subtraction to 0 and leave pp_ref_count at 0
+ * while the page is released from the pool.
*/
- if (atomic_long_read(pp_ref_count) == nr) {
+ if (atomic_long_read(pp_ref_count) == nr &&
+ likely(page_pool_netmem_is_exclusively_owned(netmem))) {
/* As we have ensured nr is always one for constant case using
* the BUILD_BUG_ON(), only need to handle the non-constant case
* here for pp_ref_count draining, which is a rare case.
@@ -304,12 +325,16 @@ static inline long page_pool_unref_netmem(netmem_ref netmem, long nr)
ret = atomic_long_sub_return(nr, pp_ref_count);
WARN_ON(ret < 0);
- /* We are the last user here too, reset pp_ref_count back to 1 to
- * ensure all pages have been partitioned into 1 piece initially,
- * this should be the rare case when the last two fragment users call
- * page_pool_unref_page() currently.
+ /* We are the last user here too. If the page_pool holds the sole
+ * page reference, reset pp_ref_count back to 1 to ensure all pages
+ * have been partitioned into 1 piece initially; otherwise leave
+ * pp_ref_count at 0 so concurrent napi_pp_get_page() callers fail
+ * atomic_long_inc_not_zero() while page_pool_return_netmem() releases
+ * the page (__page_pool_put_page() restores pp_ref_count to 1 if the
+ * external page reference is dropped before recycling).
*/
- if (unlikely(!ret))
+ if (unlikely(!ret) &&
+ likely(page_pool_netmem_is_exclusively_owned(netmem)))
atomic_long_set(pp_ref_count, 1);
return ret;
diff --git a/net/core/gro.c b/net/core/gro.c
index 1b033855a20db..124079f3eb9b0 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -100,15 +100,6 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
struct sk_buff *lp;
int segs;
- /* Do not splice page pool based packets w/ non-page pool
- * packets. This can result in reference count issues as page
- * pool pages will not decrement the reference count and will
- * instead be immediately returned to the pool or have frag
- * count decremented.
- */
- if (p->pp_recycle != skb->pp_recycle)
- return -ETOOMANYREFS;
-
if (skb_zcopy(p) || skb_zcopy(skb))
return -ETOOMANYREFS;
diff --git a/net/core/net_test.c b/net/core/net_test.c
index 73da75e6ca2c8..c7fef3fa12647 100644
--- a/net/core/net_test.c
+++ b/net/core/net_test.c
@@ -551,23 +551,11 @@ static void netmem_ref_test_page(struct kunit *test)
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
#endif
- /* Layer 3: skb_netmem_ref / unref fall back to non-pp on non-PP page */
- skb_netmem_ref(netmem, false);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
- skb_netmem_unref(netmem, false);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
-
- skb_netmem_ref(netmem, true);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
- skb_netmem_unref(netmem, true);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
-
- /* Layer 4: skb_frag_ref / skb_frag_unref on non-PP page */
+ /* Layer 3: skb_frag_ref / skb_frag_unref on non-PP page */
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
- skb->pp_recycle = 1;
skb_frag_ref(skb, 0);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
skb_frag_unref(skb, 0);
@@ -612,47 +600,31 @@ static void netmem_ref_test_pp_page(struct kunit *test)
base_ref = page_ref_count(page);
base_pp_ref = atomic_long_read(&page->pp_ref_count);
- /* Layer 1: netmem_inc/dec_ref always use non-pp refcount */
+ /* Layer 1: netmem_inc/dec_ref use pp_ref_count on PP page */
netmem_inc_ref(netmem);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
- KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
- base_pp_ref);
- netmem_dec_ref(netmem);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
-
- /* Layer 2: napi_pp_get/put_page use pp_ref_count */
- KUNIT_EXPECT_TRUE(test, napi_pp_get_page(netmem));
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
- KUNIT_EXPECT_TRUE(test, napi_pp_put_page(netmem));
- KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
- base_pp_ref);
-
- /* Layer 3: skb_netmem_ref / unref obey recycle flag */
- skb_netmem_ref(netmem, false);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
+ netmem_dec_ref(netmem);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- skb_netmem_unref(netmem, false);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
- skb_netmem_ref(netmem, true);
+ /* Layer 2: napi_pp_get/put_page use pp_ref_count */
+ KUNIT_EXPECT_TRUE(test, napi_pp_get_page(netmem));
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
- skb_netmem_unref(netmem, true);
+ KUNIT_EXPECT_TRUE(test, napi_pp_put_page(netmem));
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- /* Layer 4: skb_frag_ref / skb_frag_unref match on pp_recycle=1 & 0 */
+ /* Layer 3: skb_frag_ref / skb_frag_unref use pp_ref_count on PP page */
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len = 64;
skb->data_len = 64;
- skb->pp_recycle = 1;
skb_frag_ref(skb, 0);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
@@ -661,10 +633,9 @@ static void netmem_ref_test_pp_page(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- /* pskb_copy on pp_recycle=1 skb propagates pp_recycle & pp_ref_count */
+ /* pskb_copy on PP page skb propagates pp_ref_count */
copy = pskb_copy(skb, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, copy);
- KUNIT_EXPECT_TRUE(test, copy->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -673,14 +644,13 @@ static void netmem_ref_test_pp_page(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- /* skb_zerocopy on pp_recycle=1 skb propagates pp_ref_count */
+ /* skb_zerocopy on PP page skb propagates pp_ref_count */
copy = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, copy);
skb_put(copy, skb_tailroom(copy));
skb->head_frag = 1;
KUNIT_ASSERT_EQ(test, skb_zerocopy(copy, skb, skb->len, 0), 0);
skb->head_frag = 0;
- KUNIT_EXPECT_TRUE(test, copy->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -689,11 +659,10 @@ static void netmem_ref_test_pp_page(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- /* skb_clone + pskb_expand_head preserves pp_recycle and pp_ref_count */
+ /* skb_clone + pskb_expand_head preserves pp_ref_count */
clone = skb_clone(skb, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, clone);
KUNIT_ASSERT_EQ(test, pskb_expand_head(clone, 32, 0, GFP_KERNEL), 0);
- KUNIT_EXPECT_TRUE(test, clone->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -714,7 +683,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
split = alloc_skb(32, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, split);
skb_split(skb, split, 16);
- KUNIT_EXPECT_TRUE(test, split->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -730,7 +698,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
split = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, split);
skb_split(skb, split, 32);
- KUNIT_EXPECT_TRUE(test, split->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -739,14 +706,13 @@ static void netmem_ref_test_pp_page(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref);
- /* skb_segment on pp_recycle=1 skb propagates pp_recycle to segments */
+ /* skb_segment on PP page skb propagates pp_ref_count to segments */
skb->protocol = htons(ETH_P_IP);
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_shinfo(skb)->gso_size = 16;
split = skb_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(split));
- KUNIT_EXPECT_TRUE(test, split->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -765,7 +731,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
skb->data_len = 64;
split = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, split);
- split->pp_recycle = 1;
KUNIT_EXPECT_EQ(test, skb_shift(split, skb, 16), 16);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
@@ -782,17 +747,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
skb_shinfo(split)->nr_frags = 0;
consume_skb(split);
page_pool_put_full_page(pool, page, false);
- skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
- skb->len = 64;
- skb->data_len = 64;
-
- skb->pp_recycle = 0;
- skb_frag_ref(skb, 0);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref + 1);
- KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
- base_pp_ref);
- skb_frag_unref(skb, 0);
- KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
skb_shinfo(skb)->nr_frags = 0;
consume_skb(skb);
@@ -800,7 +754,7 @@ static void netmem_ref_test_pp_page(struct kunit *test)
page_pool_destroy(pool);
/* Order-1 compound page_pool page: tail netmem resolves to head &
- * build_skb(head_frag=1, pp_recycle=1) skb_zerocopy uses pp_ref_count.
+ * build_skb(head_frag=1) skb_zerocopy uses pp_ref_count.
*/
pp_params.order = 1;
pool = page_pool_create(&pp_params);
@@ -821,7 +775,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
skb = build_skb(page_address(page), PAGE_SIZE);
KUNIT_ASSERT_NOT_NULL(test, skb);
- skb->pp_recycle = 1;
skb_put(skb, 64);
page_pool_ref_page(page);
@@ -829,7 +782,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
KUNIT_ASSERT_NOT_NULL(test, copy);
skb_put(copy, skb_tailroom(copy));
KUNIT_ASSERT_EQ(test, skb_zerocopy(copy, skb, skb->len, 0), 0);
- KUNIT_EXPECT_TRUE(test, copy->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -844,9 +796,6 @@ static void netmem_ref_test_pp_page(struct kunit *test)
page_pool_destroy(pool);
}
-int zerocopy_fill_skb_from_iter(struct sk_buff *skb,
- struct iov_iter *from, size_t length);
-
static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
{
struct page_pool_params pp_params = {
@@ -871,7 +820,9 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
base_pp_ref = atomic_long_read(&pp_page->pp_ref_count);
/* 1. Single order-0 page_pool page (simulating TCP_ZEROCOPY_RECEIVE
- * page forwarded into MSG_ZEROCOPY TX via zerocopy_fill_skb_from_iter).
+ * page forwarded into MSG_ZEROCOPY TX via zerocopy_fill_skb_from_iter):
+ * GUP _refcount from iov_iter_get_pages2() is converted to pp_ref_count
+ * and released via netmem_dec_ref() on consume_skb().
*/
skb = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
@@ -880,16 +831,17 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
KUNIT_ASSERT_EQ(test, zerocopy_fill_skb_from_iter(skb, &iter, 128), 0);
KUNIT_EXPECT_EQ(test, skb_shinfo(skb)->nr_frags, 1);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
- base_pp_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref + 1);
+ base_pp_ref + 1);
+ KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
consume_skb(skb);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
/* 2. Contiguous segments on the same page_pool page coalesce into a
- * single skb_frag_t while a non-contiguous segment creates a second
- * skb_frag_t; all 3 GUP _refcounts are dropped.
+ * single skb_frag_t (1 pp_ref_count) while a non-contiguous segment
+ * creates a second skb_frag_t (+1 pp_ref_count); all 3 GUP _refcounts
+ * are dropped.
*/
skb = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
@@ -902,17 +854,17 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
KUNIT_EXPECT_EQ(test, skb_frag_size(&skb_shinfo(skb)->frags[0]), 128U);
KUNIT_EXPECT_EQ(test, skb_frag_size(&skb_shinfo(skb)->frags[1]), 64U);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
- base_pp_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref + 2);
+ base_pp_ref + 2);
+ KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
consume_skb(skb);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
/* 3. Order-1 compound page_pool page spanning 2 subpages in a single
- * iov_iter_get_pages2() batch coalesces into 1 skb_frag_t and drops
- * both GUP _refcounts via batched page_ref_sub, alongside a
- * non-page_pool page in the same skb.
+ * iov_iter_get_pages2() batch coalesces into 1 skb_frag_t with 1
+ * pp_ref_count and drops both GUP _refcounts via batched page_ref_sub,
+ * alongside a non-page_pool page in the same skb.
*/
pp_params.order = 1;
comp_pool = page_pool_create(&pp_params);
@@ -938,8 +890,8 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
KUNIT_EXPECT_EQ(test, skb_frag_size(&skb_shinfo(skb)->frags[0]),
(unsigned int)(2 * PAGE_SIZE));
KUNIT_EXPECT_EQ(test, atomic_long_read(&comp_page->pp_ref_count),
- base_comp_pp_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(comp_page), base_comp_ref + 1);
+ base_comp_pp_ref + 1);
+ KUNIT_EXPECT_EQ(test, page_ref_count(comp_page), base_comp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref + 1);
consume_skb(skb);
KUNIT_EXPECT_EQ(test, atomic_long_read(&comp_page->pp_ref_count),
@@ -965,12 +917,12 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
3 * PAGE_SIZE + 64), 0);
KUNIT_EXPECT_EQ(test, skb_shinfo(skb)->nr_frags, 3);
KUNIT_EXPECT_EQ(test, atomic_long_read(&comp_page->pp_ref_count),
- base_comp_pp_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(comp_page), base_comp_ref + 1);
+ base_comp_pp_ref + 1);
+ KUNIT_EXPECT_EQ(test, page_ref_count(comp_page), base_comp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref + 1);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
- base_pp_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref + 1);
+ base_pp_ref + 1);
+ KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
consume_skb(skb);
KUNIT_EXPECT_EQ(test, atomic_long_read(&comp_page->pp_ref_count),
base_comp_pp_ref);
@@ -980,6 +932,29 @@ static void netmem_ref_test_zerocopy_fill_skb_from_iter(struct kunit *test)
base_pp_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref);
+ /* 5. Concurrent final pp_ref_count unref race window: when a user VMA
+ * or GUP pin holds an external page_ref_count (> 1) and the last
+ * page_pool holder drops pp_ref_count via page_pool_unref_page(),
+ * pp_ref_count transitions to 0. Even before page_pool_return_netmem()
+ * clears pp_magic, zerocopy_fill_skb_from_iter() and consume_skb()
+ * must fall back to page_ref_count without touching pp_ref_count.
+ */
+ get_page(pp_page);
+ KUNIT_EXPECT_EQ(test, page_pool_unref_page(pp_page, 1), 0L);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count), 0L);
+ skb = alloc_skb(0, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, skb);
+ bvec_set_page(&bvec[0], pp_page, 128, 0);
+ iov_iter_bvec(&iter, ITER_SOURCE, bvec, 1, 128);
+ KUNIT_ASSERT_EQ(test, zerocopy_fill_skb_from_iter(skb, &iter, 128), 0);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count), 0L);
+ KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref + 2);
+ consume_skb(skb);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count), 0L);
+ KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_ref + 1);
+ put_page(pp_page);
+ atomic_long_set(&pp_page->pp_ref_count, base_pp_ref);
+
__free_page(reg_page);
page_pool_put_full_page(comp_pool, comp_page, false);
page_pool_destroy(comp_pool);
@@ -1027,10 +1002,10 @@ static void netmem_ref_test_net_iov(struct kunit *test)
KUNIT_EXPECT_FALSE(test, napi_pp_get_page(netmem));
KUNIT_EXPECT_FALSE(test, napi_pp_put_page(netmem));
- skb_netmem_ref(netmem, true);
+ netmem_inc_ref(netmem);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref + 1);
- skb_netmem_unref(netmem, true);
+ netmem_dec_ref(netmem);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref);
@@ -1041,7 +1016,7 @@ static void netmem_ref_test_net_iov(struct kunit *test)
netmem_or_pp_magic(netmem, PP_SIGNATURE);
atomic_long_set(&niov.desc.pp_ref_count, 2);
- /* Layer 0 & 1: net_iov/netmem_inc_ref grab non-pp ref on PP */
+ /* Layer 0 & 1: net_iov_inc_ref uses binding.ref, netmem_inc_ref pp */
net_iov_inc_ref(&niov);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref + 1);
@@ -1050,6 +1025,13 @@ static void netmem_ref_test_net_iov(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref);
+ netmem_inc_ref(netmem);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
+ base_ref);
+ netmem_dec_ref(netmem);
+ KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
+
/* Layer 2: napi_pp_get/put_page use pp_ref_count */
KUNIT_EXPECT_TRUE(test, napi_pp_get_page(netmem));
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
@@ -1058,14 +1040,13 @@ static void netmem_ref_test_net_iov(struct kunit *test)
KUNIT_EXPECT_TRUE(test, napi_pp_put_page(netmem));
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
- /* Layer 4: skb_frag_ref / skb_frag_unref on PP net_iov */
+ /* Layer 3: skb_frag_ref / skb_frag_unref on PP net_iov */
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len = 64;
skb->data_len = 64;
- skb->pp_recycle = 1;
skb_frag_ref(skb, 0);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
@@ -1073,17 +1054,16 @@ static void netmem_ref_test_net_iov(struct kunit *test)
skb_frag_unref(skb, 0);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
- /* pskb_copy on pp_recycle=1 net_iov skb keeps pp_ref_count */
+ /* pskb_copy on PP net_iov skb keeps pp_ref_count */
copy = pskb_copy(skb, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, copy);
- KUNIT_EXPECT_TRUE(test, copy->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref);
consume_skb(copy);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
- /* skb_zerocopy on pp_recycle=1 net_iov skb keeps pp_ref_count */
+ /* skb_zerocopy on PP net_iov skb keeps pp_ref_count */
copy = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, copy);
skb_put(copy, skb_tailroom(copy));
@@ -1091,7 +1071,6 @@ static void netmem_ref_test_net_iov(struct kunit *test)
skb->unreadable = 1;
KUNIT_ASSERT_EQ(test, skb_zerocopy(copy, skb, skb->len, 0), 0);
skb->head_frag = 0;
- KUNIT_EXPECT_TRUE(test, copy->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref);
@@ -1101,7 +1080,6 @@ static void netmem_ref_test_net_iov(struct kunit *test)
/* skb_shift balances pp_ref_count on split and merge */
copy = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, copy);
- copy->pp_recycle = 1;
KUNIT_EXPECT_EQ(test, skb_shift(copy, skb, 16), 16);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
@@ -1114,26 +1092,16 @@ static void netmem_ref_test_net_iov(struct kunit *test)
skb->len = 64;
skb->data_len = 64;
- /* Uncloning a cloned pp_recycle=1 net_iov skb keeps pp_ref_count */
+ /* Uncloning a cloned PP net_iov skb keeps pp_ref_count */
clone = skb_clone(skb, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, clone);
KUNIT_ASSERT_EQ(test, pskb_expand_head(skb, 32, 0, GFP_KERNEL), 0);
- KUNIT_EXPECT_TRUE(test, skb->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_ref);
consume_skb(clone);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
- skb->pp_recycle = 0;
- skb_frag_ref(skb, 0);
- KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
- base_ref + 1);
- KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
- skb_frag_unref(skb, 0);
- KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
- base_ref);
-
skb_shinfo(skb)->nr_frags = 0;
consume_skb(skb);
netmem_clear_pp_magic(netmem);
@@ -1170,7 +1138,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_put(skb, 32);
- skb->pp_recycle = 1;
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len += 64;
skb->data_len = 64;
@@ -1183,14 +1150,11 @@ static void netmem_ref_test_release_data(struct kunit *test)
clone2 = skb_clone(clone1, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, clone2);
- /* Freeing head skb first leaves clone1/clone2 pp_recycle=1 intact */
+ /* Freeing head skb first leaves clone1/clone2 intact */
consume_skb(skb);
- KUNIT_EXPECT_TRUE(test, clone1->pp_recycle);
- KUNIT_EXPECT_TRUE(test, clone2->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
consume_skb(clone2);
- KUNIT_EXPECT_TRUE(test, clone1->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
consume_skb(clone1);
@@ -1202,7 +1166,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_put(skb, 32);
- skb->pp_recycle = 1;
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len += 64;
skb->data_len = 64;
@@ -1213,8 +1176,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
KUNIT_ASSERT_EQ(test,
pskb_expand_head((i & 1) ? clone1 : skb,
32, 0, GFP_KERNEL), 0);
- KUNIT_EXPECT_TRUE(test, skb->pp_recycle);
- KUNIT_EXPECT_TRUE(test, clone1->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -1241,7 +1202,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_put(skb, 32);
- skb->pp_recycle = 1;
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len += 64;
skb->data_len = 64;
@@ -1250,7 +1210,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
/* Carve inside header keeping frag -> pp_ref_count +1 until free */
ext = pskb_extract(skb, 16, skb->len - 16, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, ext);
- KUNIT_EXPECT_TRUE(test, ext->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -1261,7 +1220,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
/* Carve + trim + skb_condense ref/unrefs pp_ref_count cleanly */
ext = pskb_extract(skb, 16, 48, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, ext);
- KUNIT_EXPECT_TRUE(test, ext->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -1270,7 +1228,6 @@ static void netmem_ref_test_release_data(struct kunit *test)
/* Carve inside nonlinear keeping frag -> pp_ref_count +1 until free */
ext = pskb_extract(skb, 48, skb->len - 48, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, ext);
- KUNIT_EXPECT_TRUE(test, ext->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(page), base_ref);
@@ -1282,12 +1239,10 @@ static void netmem_ref_test_release_data(struct kunit *test)
page_pool_ref_netmem(netmem);
clone1 = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, clone1);
- clone1->pp_recycle = 1;
skb_fill_netmem_desc(clone1, 0, netmem, 0, 64);
clone1->len = 64;
clone1->data_len = 64;
skb_morph(clone1, skb);
- KUNIT_EXPECT_TRUE(test, clone1->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&page->pp_ref_count),
base_pp_ref + 1);
consume_skb(clone1);
@@ -1309,14 +1264,12 @@ static void netmem_ref_test_release_data(struct kunit *test)
skb = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
skb_put(skb, 32);
- skb->pp_recycle = 1;
skb_fill_netmem_desc(skb, 0, netmem, 0, 64);
skb->len += 64;
skb->data_len = 64;
ext = pskb_extract(skb, 48, skb->len - 48, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, ext);
- KUNIT_EXPECT_TRUE(test, ext->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 3L);
consume_skb(ext);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 2L);
@@ -1375,7 +1328,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
/* 1. Single GSO skb with page_pool net_iov frags */
head = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, head);
- head->pp_recycle = 1;
head->protocol = htons(ETH_P_IP);
skb_reset_mac_header(head);
skb_reset_network_header(head);
@@ -1386,8 +1338,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
segs = skb_segment(head, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(segs));
- for (seg = segs; seg; seg = seg->next)
- KUNIT_EXPECT_TRUE(test, seg->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&niov.desc.pp_ref_count), 6L);
KUNIT_EXPECT_EQ(test, atomic_long_read(&binding.ref.data->count),
base_iov_ref);
@@ -1396,13 +1346,11 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
skb_shinfo(head)->nr_frags = 0;
consume_skb(head);
- /* 2. GRO frag_list fast path (skb_clone of pp_recycle=1 list_skb) */
+ /* 2. GRO frag_list fast path (skb_clone of list_skb) */
head = alloc_skb(64, GFP_KERNEL);
list = alloc_skb(64, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, head);
KUNIT_ASSERT_NOT_NULL(test, list);
- head->pp_recycle = 1;
- list->pp_recycle = 1;
head->protocol = htons(ETH_P_IP);
skb_reset_mac_header(head);
skb_reset_network_header(head);
@@ -1425,8 +1373,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
segs = skb_segment(head, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(segs));
- for (seg = segs; seg; seg = seg->next)
- KUNIT_EXPECT_TRUE(test, seg->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref + 4);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
@@ -1437,17 +1383,14 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref);
- /* 3. Mixed GRO frag_list (head pp_recycle=1 + list pp_recycle=0):
- * straddling segment linearizes its pp_recycle=1 prefix before
- * attaching the pp_recycle=0 frag so no nskb mixes incompatible
- * fragment refcount types; non-straddling segments stay zero-copy SG.
+ /* 3. Mixed GRO frag_list (head PP page + list non-PP page):
+ * straddling segment stays zero-copy SG and refs each frag by netmem
+ * type (pp_ref_count for pp_page, page_ref_count for reg_page).
*/
head = alloc_skb(64, GFP_KERNEL);
list = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, head);
KUNIT_ASSERT_NOT_NULL(test, list);
- head->pp_recycle = 1;
- list->pp_recycle = 0;
head->protocol = htons(ETH_P_IP);
skb_reset_mac_header(head);
skb_reset_network_header(head);
@@ -1468,11 +1411,8 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
segs = skb_segment(head, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(segs));
- KUNIT_EXPECT_TRUE(test, segs->pp_recycle);
- KUNIT_EXPECT_FALSE(test, segs->next->pp_recycle);
- KUNIT_EXPECT_FALSE(test, segs->next->next->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
- base_pp_ref + 2);
+ base_pp_ref + 3);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref + 3);
kfree_skb_list(segs);
@@ -1482,16 +1422,14 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref);
- /* 4. Reverse mixed frag_list (head pp_recycle=0 + list pp_recycle=1):
- * Crossing from pp_recycle=0 head into pp_recycle=1 list_skb must not
- * elevate page_ref_count(pp_page) instead of pp_ref_count.
+ /* 4. Reverse mixed frag_list (head non-PP page + list PP page):
+ * Crossing from non-PP head into PP list_skb increments pp_ref_count
+ * on pp_page without elevating page_ref_count(pp_page).
*/
head = alloc_skb(64, GFP_KERNEL);
list = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, head);
KUNIT_ASSERT_NOT_NULL(test, list);
- head->pp_recycle = 0;
- list->pp_recycle = 1;
head->protocol = htons(ETH_P_IP);
skb_reset_mac_header(head);
skb_reset_network_header(head);
@@ -1512,13 +1450,10 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
segs = skb_segment(head, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(segs));
- KUNIT_EXPECT_FALSE(test, segs->pp_recycle);
- KUNIT_EXPECT_TRUE(test, segs->next->pp_recycle);
- KUNIT_EXPECT_TRUE(test, segs->next->next->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref + 3);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
- KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref + 2);
+ KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref + 3);
kfree_skb_list(segs);
consume_skb(head);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
@@ -1526,10 +1461,10 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref);
- /* 5. Linear head_skb (nr_frags=0) + mixed pp_recycle frag_list where
- * member A has linear + frag (pp_recycle=1) and tail member B has
- * linear len == skb_headlen(A) (pp_recycle=0): keeps SG clone path
- * synchronized without hitting BUG_ON(i >= nfrags).
+ /* 5. Linear head_skb (nr_frags=0) + mixed frag_list where member A has
+ * linear + frag (PP page) and tail member B has linear len ==
+ * skb_headlen(A): keeps SG clone path synchronized without hitting
+ * BUG_ON(i >= nfrags).
*/
head = alloc_skb(64, GFP_KERNEL);
list = alloc_skb(64, GFP_KERNEL);
@@ -1537,9 +1472,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
KUNIT_ASSERT_NOT_NULL(test, head);
KUNIT_ASSERT_NOT_NULL(test, list);
KUNIT_ASSERT_NOT_NULL(test, seg);
- head->pp_recycle = 0;
- list->pp_recycle = 1;
- seg->pp_recycle = 0;
head->protocol = htons(ETH_P_IP);
skb_reset_mac_header(head);
skb_reset_network_header(head);
@@ -1558,9 +1490,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
segs = skb_segment(head, NETIF_F_SG | NETIF_F_HW_CSUM);
KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(segs));
- KUNIT_EXPECT_FALSE(test, segs->pp_recycle);
- KUNIT_EXPECT_TRUE(test, segs->next->pp_recycle);
- KUNIT_EXPECT_FALSE(test, segs->next->next->pp_recycle);
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref + 2);
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
@@ -1575,7 +1504,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
*/
head = build_skb(page_address(pp_page), PAGE_SIZE);
KUNIT_ASSERT_NOT_NULL(test, head);
- head->pp_recycle = 1;
skb_put(head, 32);
page_pool_ref_netmem(pp_nm);
skb_fill_netmem_desc(head, 0, niov_nm, 0, 32);
@@ -1601,7 +1529,6 @@ static void netmem_ref_test_skb_segment(struct kunit *test)
*/
head = build_skb(page_address(pp_page), PAGE_SIZE);
KUNIT_ASSERT_NOT_NULL(test, head);
- head->pp_recycle = 1;
skb_put(head, 32);
page_pool_ref_netmem(pp_nm);
skb_zcopy_init(head, &uarg);
@@ -1674,14 +1601,12 @@ static void netmem_ref_test_try_coalesce(struct kunit *test)
base_reg_ref = page_ref_count(reg_page);
base_iov_ref = atomic_long_read(&binding.ref.data->count);
- /* 1. Uncloned pp_recycle=1 from: frags stolen without extra ref */
+ /* 1. Uncloned from with PP page: frags stolen without extra ref */
to = alloc_skb(0, GFP_KERNEL);
from = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, to);
KUNIT_ASSERT_NOT_NULL(test, from);
skb_put(to, skb_tailroom(to));
- to->pp_recycle = 1;
- from->pp_recycle = 1;
skb_add_rx_frag(from, 0, pp_page, 0, 64, PAGE_SIZE);
page_pool_ref_netmem(pp_nm);
KUNIT_EXPECT_TRUE(test, skb_try_coalesce(to, from, &fragstolen,
@@ -1694,7 +1619,7 @@ static void netmem_ref_test_try_coalesce(struct kunit *test)
KUNIT_EXPECT_EQ(test, atomic_long_read(&pp_page->pp_ref_count),
base_pp_ref);
- /* 2. Cloned pp_recycle=1 from (pp_page + non-PP reg_page fallback):
+ /* 2. Cloned from with mixed pp_page + non-PP reg_page:
* skb_frag_ref(from, i) increments pp_ref_count for pp_page and
* page_ref_count for reg_page.
*/
@@ -1703,8 +1628,6 @@ static void netmem_ref_test_try_coalesce(struct kunit *test)
KUNIT_ASSERT_NOT_NULL(test, to);
KUNIT_ASSERT_NOT_NULL(test, from);
skb_put(to, skb_tailroom(to));
- to->pp_recycle = 1;
- from->pp_recycle = 1;
skb_add_rx_frag(from, 0, pp_page, 0, 32, PAGE_SIZE);
page_pool_ref_netmem(pp_nm);
skb_add_rx_frag(from, 1, reg_page, 0, 32, PAGE_SIZE);
@@ -1726,7 +1649,7 @@ static void netmem_ref_test_try_coalesce(struct kunit *test)
KUNIT_EXPECT_EQ(test, page_ref_count(pp_page), base_pp_page_ref);
KUNIT_EXPECT_EQ(test, page_ref_count(reg_page), base_reg_ref);
- /* 3. Cloned unreadable pp_recycle=1 net_iov skb: skb_try_coalesce
+ /* 3. Cloned unreadable PP net_iov skb: skb_try_coalesce
* increments niov.desc.pp_ref_count via skb_frag_ref(from, i).
*/
to = alloc_skb(0, GFP_KERNEL);
@@ -1734,9 +1657,7 @@ static void netmem_ref_test_try_coalesce(struct kunit *test)
KUNIT_ASSERT_NOT_NULL(test, to);
KUNIT_ASSERT_NOT_NULL(test, from);
skb_put(to, skb_tailroom(to));
- to->pp_recycle = 1;
to->unreadable = 1;
- from->pp_recycle = 1;
skb_add_rx_frag_netmem(from, 0, niov_nm, 0, 64, PAGE_SIZE);
napi_pp_get_page(niov_nm);
@@ -1819,7 +1740,6 @@ static void netmem_ref_test_tcp_devmem_recv(struct kunit *test)
/* 1. Receive via tcp_recvmsg_dmabuf -> SO_DEVMEM_DONTNEED release */
skb = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
- skb->pp_recycle = 1;
skb_add_rx_frag_netmem(skb, 0, niov_nm, 0, 64, PAGE_SIZE);
napi_pp_get_page(niov_nm);
TCP_SKB_CB(skb)->seq = 0;
@@ -1850,7 +1770,6 @@ static void netmem_ref_test_tcp_devmem_recv(struct kunit *test)
*/
skb = alloc_skb(0, GFP_KERNEL);
KUNIT_ASSERT_NOT_NULL(test, skb);
- skb->pp_recycle = 1;
skb_add_rx_frag_netmem(skb, 0, niov_nm, 0, 64, PAGE_SIZE);
napi_pp_get_page(niov_nm);
TCP_SKB_CB(skb)->seq = 64;
diff --git a/net/core/netmem_priv.h b/net/core/netmem_priv.h
index 23175cb2bd866..13c39603003e1 100644
--- a/net/core/netmem_priv.h
+++ b/net/core/netmem_priv.h
@@ -3,21 +3,30 @@
#ifndef __NETMEM_PRIV_H
#define __NETMEM_PRIV_H
+/* Use READ_ONCE() because every netmem_inc/dec_ref() checks netmem_is_pp(),
+ * and pp_magic shares a struct page union word with folio->lru.next which MM
+ * code may concurrently modify on page-cache folios in TX SKBs.
+ */
static inline unsigned long netmem_get_pp_magic(netmem_ref netmem)
{
- return netmem_to_nmdesc(netmem)->pp_magic & ~PP_DMA_INDEX_MASK;
+ return READ_ONCE(netmem_to_nmdesc(netmem)->pp_magic) &
+ ~PP_DMA_INDEX_MASK;
}
static inline void netmem_or_pp_magic(netmem_ref netmem, unsigned long pp_magic)
{
- netmem_to_nmdesc(netmem)->pp_magic |= pp_magic;
+ struct netmem_desc *nmdesc = netmem_to_nmdesc(netmem);
+
+ WRITE_ONCE(nmdesc->pp_magic, READ_ONCE(nmdesc->pp_magic) | pp_magic);
}
static inline void netmem_clear_pp_magic(netmem_ref netmem)
{
- WARN_ON_ONCE(netmem_to_nmdesc(netmem)->pp_magic & PP_DMA_INDEX_MASK);
+ struct netmem_desc *nmdesc = netmem_to_nmdesc(netmem);
+
+ WARN_ON_ONCE(READ_ONCE(nmdesc->pp_magic) & PP_DMA_INDEX_MASK);
- netmem_to_nmdesc(netmem)->pp_magic = 0;
+ WRITE_ONCE(nmdesc->pp_magic, 0);
}
static inline bool netmem_is_pp(netmem_ref netmem)
@@ -27,7 +36,7 @@ static inline bool netmem_is_pp(netmem_ref netmem)
static inline void netmem_set_pp(netmem_ref netmem, struct page_pool *pool)
{
- netmem_to_nmdesc(netmem)->pp = pool;
+ WRITE_ONCE(netmem_to_nmdesc(netmem)->pp, pool);
}
static inline void netmem_set_dma_addr(netmem_ref netmem,
@@ -43,7 +52,7 @@ static inline unsigned long netmem_get_dma_index(netmem_ref netmem)
if (WARN_ON_ONCE(netmem_is_net_iov(netmem)))
return 0;
- magic = netmem_to_nmdesc(netmem)->pp_magic;
+ magic = READ_ONCE(netmem_to_nmdesc(netmem)->pp_magic);
return (magic & PP_DMA_INDEX_MASK) >> PP_DMA_INDEX_SHIFT;
}
@@ -57,6 +66,6 @@ static inline void netmem_set_dma_index(netmem_ref netmem,
return;
magic = netmem_get_pp_magic(netmem) | (id << PP_DMA_INDEX_SHIFT);
- netmem_to_nmdesc(netmem)->pp_magic = magic;
+ WRITE_ONCE(netmem_to_nmdesc(netmem)->pp_magic, magic);
}
#endif
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index d7c88c0b67e53..87db2f2b72e8e 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -825,9 +825,9 @@ static bool page_pool_recycle_in_cache(netmem_ref netmem,
static bool __page_pool_page_can_be_recycled(netmem_ref netmem)
{
- return netmem_is_net_iov(netmem) ||
- (page_ref_count(netmem_to_page(netmem)) == 1 &&
- !page_is_pfmemalloc(netmem_to_page(netmem)));
+ return page_pool_netmem_is_exclusively_owned(netmem) &&
+ (netmem_is_net_iov(netmem) ||
+ !page_is_pfmemalloc(__netmem_to_page(netmem)));
}
/* If the page refcnt == 1, this will try to recycle the page.
@@ -853,6 +853,8 @@ __page_pool_put_page(struct page_pool *pool, netmem_ref netmem,
*/
if (likely(__page_pool_page_can_be_recycled(netmem))) {
/* Read barrier done in page_ref_count / READ_ONCE */
+ if (unlikely(!page_pool_ref_count(netmem)))
+ page_pool_fragment_netmem(netmem, 1);
page_pool_dma_sync_for_device(pool, netmem, dma_sync_size);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 32a9dcdf2cb22..e3b969e38db65 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1032,15 +1032,16 @@ EXPORT_SYMBOL(skb_cow_data_for_xdp);
* @netmem: netmem to unreference
*
* Drops a page_pool reference (pp_ref_count) on @netmem if it belongs to a
- * page_pool. Counterpart to napi_pp_get_page().
+ * page_pool and has an active pp_ref_count. Counterpart to napi_pp_get_page().
*
- * Return: true if @netmem belongs to a page_pool, false otherwise.
+ * Return: true if @netmem's page_pool reference count was decremented, false
+ * otherwise.
*/
bool napi_pp_put_page(netmem_ref netmem)
{
netmem = netmem_compound_head(netmem);
- if (unlikely(!netmem_is_pp(netmem)))
+ if (unlikely(!netmem_is_pp(netmem) || !page_pool_ref_count(netmem)))
return false;
page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false);
@@ -1054,9 +1055,10 @@ EXPORT_SYMBOL(napi_pp_put_page);
* @netmem: netmem to reference
*
* Acquires a page_pool reference (pp_ref_count) on @netmem if it belongs to a
- * page_pool. Counterpart to napi_pp_put_page().
+ * page_pool and has an active pp_ref_count. Counterpart to napi_pp_put_page().
*
- * Return: true if @netmem belongs to a page_pool, false otherwise.
+ * Return: true if @netmem's page_pool reference count was incremented, false
+ * otherwise.
*/
bool napi_pp_get_page(netmem_ref netmem)
{
@@ -1065,16 +1067,14 @@ bool napi_pp_get_page(netmem_ref netmem)
if (unlikely(!netmem_is_pp(netmem)))
return false;
- page_pool_ref_netmem(netmem);
-
- return true;
+ return atomic_long_inc_not_zero(netmem_get_pp_ref_count_ref(netmem));
}
EXPORT_SYMBOL(napi_pp_get_page);
#endif
-static bool skb_pp_recycle(struct sk_buff *skb, void *data)
+static bool skb_pp_recycle(void *data)
{
- if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle)
+ if (!IS_ENABLED(CONFIG_PAGE_POOL))
return false;
return napi_pp_put_page(page_to_netmem(virt_to_page(data)));
}
@@ -1089,7 +1089,7 @@ static void skb_free_head(struct sk_buff *skb)
unsigned char *head = skb->head;
if (skb->head_frag) {
- if (skb_pp_recycle(skb, head))
+ if (skb_pp_recycle(head))
return;
skb_free_frag(head);
} else {
@@ -1114,8 +1114,7 @@ static void skb_release_data(struct sk_buff *skb, enum skb_drop_reason reason)
}
for (i = 0; i < shinfo->nr_frags; i++)
- skb_netmem_unref(skb_frag_netmem(&shinfo->frags[i]),
- skb->pp_recycle);
+ netmem_dec_ref(skb_frag_netmem(&shinfo->frags[i]));
free_head:
if (shinfo->frag_list)
@@ -1613,7 +1612,6 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
n->nohdr = 0;
n->peeked = 0;
C(pfmemalloc);
- C(pp_recycle);
n->destructor = NULL;
C(alloc_cpu);
C(tail);
@@ -2251,7 +2249,6 @@ struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
n = NULL;
goto out;
}
- n->pp_recycle = skb->pp_recycle;
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
skb_frag_ref(n, i);
@@ -3936,7 +3933,6 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
if (len <= skb_tailroom(to))
return skb_copy_bits(from, 0, skb_put(to, len), len);
- to->pp_recycle = from->pp_recycle;
if (hlen) {
ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
if (unlikely(ret))
@@ -4309,7 +4305,6 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & zc_flags;
skb_zerocopy_clone(skb1, skb, 0);
- skb1->pp_recycle = skb->pp_recycle;
if (len < pos) /* Split line is inside header. */
skb_split_inside_header(skb, skb1, len, pos);
else /* Second chunk has no header, nothing to copy. */
@@ -4359,7 +4354,6 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
if (skb_zcopy(tgt) || skb_zcopy(skb))
return 0;
- DEBUG_NET_WARN_ON_ONCE(tgt->pp_recycle != skb->pp_recycle);
DEBUG_NET_WARN_ON_ONCE(skb_cmp_decrypted(tgt, skb));
todo = shiftlen;
@@ -5103,16 +5097,6 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
while (pos < offset + len) {
if (i >= nfrags) {
- if (skb_shinfo(nskb)->nr_frags &&
- nskb->pp_recycle != list_skb->pp_recycle) {
- nskb->data_len = pos - offset - hsize;
- nskb->len += nskb->data_len;
- nskb->truesize += nskb->data_len;
- if (__skb_linearize(nskb))
- goto err;
- hsize = pos - offset;
- nskb_frag = skb_shinfo(nskb)->frags;
- }
if (skb_orphan_frags(list_skb, GFP_ATOMIC) ||
skb_zerocopy_clone(nskb, list_skb,
GFP_ATOMIC))
@@ -5155,8 +5139,6 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
goto err;
}
- if (!skb_shinfo(nskb)->nr_frags)
- nskb->pp_recycle = frag_skb->pp_recycle;
*nskb_frag = (i < 0) ? skb_head_frag_to_page_desc(frag_skb) : *frag;
skb_frag_ref(nskb, skb_shinfo(nskb)->nr_frags);
size = skb_frag_size(nskb_frag);
@@ -6306,15 +6288,6 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
if (skb_cloned(to))
return false;
- /* In general, avoid mixing page_pool and non-page_pool allocated
- * pages within the same SKB. In theory we could take full
- * references if @from is cloned and !@to->pp_recycle but its
- * tricky (due to potential race with the clone disappearing) and
- * rare, so not worth dealing with.
- */
- if (to->pp_recycle != from->pp_recycle)
- return false;
-
/* All frags in an skb must either all be struct page-backed or all
* belong to the same memory provider instance; do not coalesce skbs
* that would mix them.
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 1d679e8fd6493..6f2b9191af9ec 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -445,7 +445,7 @@ void __xdp_return(netmem_ref netmem, enum xdp_mem_type mem_type,
napi_direct);
break;
case MEM_TYPE_PAGE_SHARED:
- page_frag_free(__netmem_address(netmem));
+ netmem_dec_ref(netmem);
break;
case MEM_TYPE_PAGE_ORDER0:
put_page(__netmem_to_page(netmem));
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index ae701561d9f12..1c37028146c98 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -96,7 +96,7 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
__alignof__(struct scatterlist));
}
-static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb, bool already_unref)
+static void esp_ssg_unref(struct xfrm_state *x, void *tmp, bool already_unref)
{
struct crypto_aead *aead = x->data;
int extralen = 0;
@@ -117,8 +117,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb,
struct scatterlist *src = already_unref ? esp_req_sg(aead, req) : req->src;
for (sg = sg_next(src); sg; sg = sg_next(sg))
- skb_netmem_unref(page_to_netmem(sg_page(sg)),
- skb->pp_recycle);
+ netmem_dec_ref(page_to_netmem(sg_page(sg)));
}
}
@@ -223,7 +222,7 @@ static void esp_output_done(void *data, int err)
}
tmp = ESP_SKB_CB(skb)->tmp;
- esp_ssg_unref(x, tmp, skb, false);
+ esp_ssg_unref(x, tmp, false);
kfree(tmp);
if (xo && (xo->flags & XFRM_DEV_RESUME)) {
@@ -579,7 +578,7 @@ int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
(unsigned char *)esph - skb->data,
assoclen + ivlen + esp->clen + alen);
if (unlikely(err < 0)) {
- esp_ssg_unref(x, tmp, skb, true);
+ esp_ssg_unref(x, tmp, true);
goto error_free;
}
}
@@ -613,7 +612,7 @@ int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
}
if (sg != dsg)
- esp_ssg_unref(x, tmp, skb, false);
+ esp_ssg_unref(x, tmp, false);
if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
err = esp_output_tail_tcp(x, skb);
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index d654f0f442388..25dd0c01f908d 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -113,7 +113,7 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
__alignof__(struct scatterlist));
}
-static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb, bool already_unref)
+static void esp_ssg_unref(struct xfrm_state *x, void *tmp, bool already_unref)
{
struct crypto_aead *aead = x->data;
int extralen = 0;
@@ -134,8 +134,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb,
struct scatterlist *src = already_unref ? esp_req_sg(aead, req) : req->src;
for (sg = sg_next(src); sg; sg = sg_next(sg))
- skb_netmem_unref(page_to_netmem(sg_page(sg)),
- skb->pp_recycle);
+ netmem_dec_ref(page_to_netmem(sg_page(sg)));
}
}
@@ -258,7 +257,7 @@ static void esp_output_done(void *data, int err)
}
tmp = ESP_SKB_CB(skb)->tmp;
- esp_ssg_unref(x, tmp, skb, false);
+ esp_ssg_unref(x, tmp, false);
kfree(tmp);
esp_output_encap_csum(skb);
@@ -611,7 +610,7 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
(unsigned char *)esph - skb->data,
assoclen + ivlen + esp->clen + alen);
if (unlikely(err < 0)) {
- esp_ssg_unref(x, tmp, skb, true);
+ esp_ssg_unref(x, tmp, true);
goto error_free;
}
}
@@ -646,7 +645,7 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
}
if (sg != dsg)
- esp_ssg_unref(x, tmp, skb, false);
+ esp_ssg_unref(x, tmp, false);
if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
err = esp_output_tail_tcp(x, skb);
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 4cdfbb57ecff0..670fdeeeae567 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -165,6 +165,7 @@ static void tls_tcp_clean_acked(struct sock *sk, u32 acked_seq)
struct tls_record_info *info, *temp;
struct tls_offload_context_tx *ctx;
u64 deleted_records = 0;
+ LIST_HEAD(to_free);
unsigned long flags;
if (!tls_ctx)
@@ -180,14 +181,15 @@ static void tls_tcp_clean_acked(struct sock *sk, u32 acked_seq)
list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
if (before(acked_seq, info->end_seq))
break;
- list_del(&info->list);
-
- destroy_record(info);
+ list_move_tail(&info->list, &to_free);
deleted_records++;
}
ctx->unacked_record_sn += deleted_records;
spin_unlock_irqrestore(&ctx->lock, flags);
+
+ list_for_each_entry_safe(info, temp, &to_free, list)
+ destroy_record(info);
}
/* At this point, there should be no references on this
@@ -269,7 +271,7 @@ static void tls_append_frag(struct tls_record_info *record,
skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
size);
++record->num_frags;
- get_page(pfrag->page);
+ netmem_inc_ref(page_to_netmem(pfrag->page));
}
pfrag->offset += size;
@@ -302,7 +304,7 @@ static int tls_push_record(struct sock *sk,
sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
skb_frag_size(frag), skb_frag_off(frag));
sk_mem_charge(sk, skb_frag_size(frag));
- get_page(skb_frag_page(frag));
+ netmem_inc_ref(skb_frag_netmem(frag));
}
sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
@@ -354,7 +356,7 @@ static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
prepend_size);
- get_page(pfrag->page);
+ netmem_inc_ref(page_to_netmem(pfrag->page));
pfrag->offset += prepend_size;
record->num_frags = 1;
diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
index b547027cc879f..b2a43b162fdac 100644
--- a/net/tls/tls_device_fallback.c
+++ b/net/tls/tls_device_fallback.c
@@ -397,8 +397,10 @@ static struct sk_buff *tls_sw_fallback(struct sock *sk, struct sk_buff *skb)
nskb = tls_enc_skb(tls_ctx, sg_out, sg_in, skb, sync_size, rcd_sn);
put_sg:
- while (resync_sgs)
- put_page(sg_page(&sg_in[--resync_sgs]));
+ while (resync_sgs) {
+ resync_sgs--;
+ netmem_dec_ref(page_to_netmem(sg_page(&sg_in[resync_sgs])));
+ }
kfree(sg_in);
free_orig:
if (nskb)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b8d5a843f7617..51d2595ebf317 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -206,7 +206,7 @@ int tls_push_sg(struct sock *sk,
return ret;
}
- put_page(p);
+ netmem_dec_ref(page_to_netmem(p));
sk_mem_uncharge(sk, sg->length);
sg = sg_next(sg);
if (!sg)
@@ -281,7 +281,7 @@ void tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
struct scatterlist *sg;
for (sg = ctx->partially_sent_record; sg; sg = sg_next(sg)) {
- put_page(sg_page(sg));
+ netmem_dec_ref(page_to_netmem(sg_page(sg)));
sk_mem_uncharge(sk, sg->length);
}
ctx->partially_sent_record = NULL;
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 59912f4a93c88..493d7e4a58617 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -10,6 +10,7 @@
#include <linux/export.h>
#include <linux/bitops.h>
#include <linux/etherdevice.h>
+#include <linux/skbuff_ref.h>
#include <linux/slab.h>
#include <linux/ieee80211.h>
#include <net/cfg80211.h>
@@ -768,19 +769,25 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
}
EXPORT_SYMBOL(ieee80211_data_to_8023_exthdr);
-static void
+static bool
__frame_add_frag(struct sk_buff *skb, struct page *page,
void *ptr, int len, int size)
{
struct skb_shared_info *sh = skb_shinfo(skb);
+ int i = sh->nr_frags;
int page_offset;
- get_page(page);
+ if (i >= MAX_SKB_FRAGS)
+ return false;
+
page_offset = ptr - page_address(page);
- skb_add_rx_frag(skb, sh->nr_frags, page, page_offset, len, size);
+ skb_add_rx_frag(skb, i, page, page_offset, len, size);
+ skb_frag_ref(skb, i);
+
+ return true;
}
-static void
+static bool
__ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
int offset, int len)
{
@@ -809,17 +816,22 @@ __ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
cur_len = min(len, frag_len);
- __frame_add_frag(frame, frag_page, frag_ptr, cur_len, frag_size);
+ if (!__frame_add_frag(frame, frag_page, frag_ptr, cur_len, frag_size))
+ return false;
len -= cur_len;
while (len > 0) {
frag_len = skb_frag_size(frag);
cur_len = min(len, frag_len);
- __frame_add_frag(frame, skb_frag_page(frag),
- skb_frag_address(frag), cur_len, frag_len);
+ if (!__frame_add_frag(frame, skb_frag_page(frag),
+ skb_frag_address(frag), cur_len,
+ frag_len))
+ return false;
len -= cur_len;
frag++;
}
+
+ return true;
}
static struct sk_buff *
@@ -858,7 +870,10 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen,
return frame;
offset += cur_len;
- __ieee80211_amsdu_copy_frag(skb, frame, offset, len);
+ if (!__ieee80211_amsdu_copy_frag(skb, frame, offset, len)) {
+ kfree_skb(frame);
+ return NULL;
+ }
return frame;
}
diff --git a/net/xfrm/trace_iptfs.h b/net/xfrm/trace_iptfs.h
index 74391ba244453..ecfd3f1f36d1f 100644
--- a/net/xfrm/trace_iptfs.h
+++ b/net/xfrm/trace_iptfs.h
@@ -167,7 +167,6 @@ TRACE_EVENT(iptfs_ingress_nth_add, TP_PROTO(struct sk_buff *skb, u8 share_ok),
__field(u32, data_len)
__field(u8, share_ok)
__field(u8, head_frag)
- __field(u8, pp_recycle)
__field(u8, cloned)
__field(u8, shared)
__field(u8, nr_frags)
@@ -178,15 +177,14 @@ TRACE_EVENT(iptfs_ingress_nth_add, TP_PROTO(struct sk_buff *skb, u8 share_ok),
__entry->data_len = skb->data_len;
__entry->share_ok = share_ok;
__entry->head_frag = skb->head_frag;
- __entry->pp_recycle = skb->pp_recycle;
__entry->cloned = skb_cloned(skb);
__entry->shared = skb_shared(skb);
__entry->nr_frags = skb_shinfo(skb)->nr_frags;
__entry->frag_list = (bool)skb_shinfo(skb)->frag_list;
),
- TP_printk("INGRPSTQ: NTHADD: skb=%p len=%u data_len=%u share_ok=%u head_frag=%u pp_recycle=%u cloned=%u shared=%u nr_frags=%u frag_list=%u",
+ TP_printk("INGRPSTQ: NTHADD: skb=%p len=%u data_len=%u share_ok=%u head_frag=%u cloned=%u shared=%u nr_frags=%u frag_list=%u",
__entry->skb, __entry->skb_len, __entry->data_len, __entry->share_ok,
- __entry->head_frag, __entry->pp_recycle, __entry->cloned, __entry->shared,
+ __entry->head_frag, __entry->cloned, __entry->shared,
__entry->nr_frags, __entry->frag_list));
DECLARE_EVENT_CLASS(iptfs_timer_event,
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 04ef833074fc8..f441aa54dcf1f 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -310,7 +310,6 @@ static void iptfs_skb_head_to_frag(const struct sk_buff *skb, skb_frag_t *frag)
* @nr_frags: number of fragments present in array
* @initial_offset: the value passed in to skb_prepare_frag_walk()
* @frags: the page fragments inc. room for head page
- * @pp_recycle: copy of skb->pp_recycle
*/
struct iptfs_skb_frag_walk {
u32 fragi;
@@ -319,7 +318,6 @@ struct iptfs_skb_frag_walk {
u32 nr_frags;
u32 initial_offset;
skb_frag_t frags[MAX_SKB_FRAGS + 1];
- bool pp_recycle;
};
/**
@@ -343,7 +341,6 @@ static void iptfs_skb_prepare_frag_walk(struct sk_buff *skb, u32 initial_offset,
walk->past = 0;
walk->total = 0;
walk->nr_frags = 0;
- walk->pp_recycle = skb->pp_recycle;
if (skb->head_frag) {
if (initial_offset >= skb_headlen(skb)) {
@@ -413,7 +410,7 @@ static bool iptfs_skb_can_add_frags(const struct sk_buff *skb,
struct skb_shared_info *shinfo = skb_shinfo(skb);
u32 fragi, nr_frags, fraglen;
- if (skb_has_frag_list(skb) || skb->pp_recycle != walk->pp_recycle)
+ if (skb_has_frag_list(skb))
return false;
/* Reject an @offset that is at or beyond the end of the walk's data
@@ -898,8 +895,7 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq,
/* If we may have the opportunity to share prepare a fragwalk. */
if (!skb_has_frag_list(skb) && !skb_has_frag_list(newskb) &&
- (skb->head_frag || skb->len == skb->data_len) &&
- skb->pp_recycle == newskb->pp_recycle) {
+ (skb->head_frag || skb->len == skb->data_len)) {
fragwalk = &_fragwalk;
iptfs_skb_prepare_frag_walk(skb, data, fragwalk);
}
@@ -2289,15 +2285,10 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
}
}
- /* skb->pp_recycle is passed to __skb_flag_unref for all
- * frag pages so we can only share pages with skb's who
- * match ourselves.
- */
shi2 = skb_shinfo(skb2);
if (share_ok &&
(shi2->frag_list ||
(!skb2->head_frag && skb_headlen(skb)) ||
- skb->pp_recycle != skb2->pp_recycle ||
skb_zcopy(skb2) ||
(shi->nr_frags + shi2->nr_frags + 1 > MAX_SKB_FRAGS)))
share_ok = false;
--
2.56.0.385.gac671c819a-goog
next prev parent reply other threads:[~2026-11-03 21:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 21:14 [PATCH net-next v1 0/5] net: deprecate skb->pp_recycle and skb_mark_for_recycle() Mina Almasry
2026-11-03 21:14 ` [PATCH net-next v1 1/5] net: skbuff: skip managed zerocopy frags in skb_frag_ref() Mina Almasry
2026-11-03 21:14 ` [PATCH net-next v1 2/5] net: skbuff: refcount spliced page_pool frags via skb_pipe_buf_ops Mina Almasry
2026-11-03 21:14 ` [PATCH net-next v1 3/5] net: datagram: refcount page_pool frags in zerocopy_fill_skb_from_iter() Mina Almasry
2026-11-03 21:14 ` Mina Almasry [this message]
2026-11-03 21:14 ` [PATCH net-next v1 5/5] net: remove skb_mark_for_recycle() Mina Almasry
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