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authorArjun Roy <arjunroy@google.com>2020-12-03 01:53:46 +0300
committerJakub Kicinski <kuba@kernel.org>2020-12-05 00:40:53 +0300
commit936ced415751f744654f64977ddbf67d17a2a45a (patch)
tree77b7b5c2672a902ad70db1dfae9fe10f4922657f /net/ipv4
parent98917cf0d6eda01e8c3c34d35398d46b247b6fd3 (diff)
downloadlinux-936ced415751f744654f64977ddbf67d17a2a45a.tar.xz
net-zerocopy: Fast return if inq < PAGE_SIZE
Sometimes, we may call tcp receive zerocopy when inq is 0, or inq < PAGE_SIZE, in which case we cannot remap pages. In this case, simply return the appropriate hint for regular copying without taking mmap_sem. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index aa1040b5a977..b9e44ad2b40d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1904,6 +1904,14 @@ static int tcp_zerocopy_receive(struct sock *sk,
sock_rps_record_flow(sk);
+ if (inq < PAGE_SIZE) {
+ zc->length = 0;
+ zc->recv_skip_hint = inq;
+ if (!inq && sock_flag(sk, SOCK_DONE))
+ return -EIO;
+ return 0;
+ }
+
mmap_read_lock(current->mm);
vma = find_vma(current->mm, address);