| Message ID | 20250218165714.56427-2-dw@davidwei.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | io_uring zc rx single shot recvzc | expand |
On 2/18/25 16:57, David Wei wrote: > Currently only multishot recvzc requests are supported, but sometimes > there is a need to do a single recv e.g. peeking at some data in the > socket. Add single shot recvzc requests where IORING_RECV_MULTISHOT is > _not_ set and the sqe->len field is set to the number of bytes to read > N. > > There could be multiple completions containing data, like the multishot > case, since N bytes could be split across multiple frags. This is > followed by a final completion with res and cflags both set to 0 that > indicate the completion of the request, or a -res that indicate an > error. > > Signed-off-by: David Wei <dw@davidwei.uk> > --- > io_uring/net.c | 26 ++++++++++++++++++-------- > io_uring/zcrx.c | 17 ++++++++++++++--- > io_uring/zcrx.h | 2 +- > 3 files changed, 33 insertions(+), 12 deletions(-) > > diff --git a/io_uring/net.c b/io_uring/net.c > index 000dc70d08d0..d3a9aaa52a13 100644 > --- a/io_uring/net.c > +++ b/io_uring/net.c > @@ -94,6 +94,7 @@ struct io_recvzc { > struct file *file; > unsigned msg_flags; > u16 flags; > + u32 len; Something is up with the types, it's u32, for which you use UINT_MAX, and later convert to ulong. > struct io_zcrx_ifq *ifq; > }; > ... > @@ -1250,6 +1251,9 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) > zc->ifq = req->ctx->ifq; > if (!zc->ifq) > return -EINVAL; > + zc->len = READ_ONCE(sqe->len); > + if (zc->len == UINT_MAX) > + return -EINVAL; > > zc->flags = READ_ONCE(sqe->ioprio); > zc->msg_flags = READ_ONCE(sqe->msg_flags); > @@ -1257,12 +1261,14 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) > return -EINVAL; > if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)) > return -EINVAL; > - /* multishot required */ > - if (!(zc->flags & IORING_RECV_MULTISHOT)) > - return -EINVAL; > - /* All data completions are posted as aux CQEs. */ > - req->flags |= REQ_F_APOLL_MULTISHOT; > - > + if (zc->flags & IORING_RECV_MULTISHOT) { > + if (zc->len) > + return -EINVAL; > + /* All data completions are posted as aux CQEs. */ > + req->flags |= REQ_F_APOLL_MULTISHOT; If you're posting "aux" cqes you have to set the flag for synchronisation reasons. We probably can split out a "I want to post aux cqes" flag, but it seems like you don't actually care about multishot here but limiting the length, or limiting the length + nowait. > + } > + if (!zc->len) > + zc->len = UINT_MAX; > return 0; > } > > @@ -1281,7 +1287,7 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) > return -ENOTSOCK; > > ret = io_zcrx_recv(req, zc->ifq, sock, zc->msg_flags | MSG_DONTWAIT, > - issue_flags); > + issue_flags, zc->len); > if (unlikely(ret <= 0) && ret != -EAGAIN) { > if (ret == -ERESTARTSYS) > ret = -EINTR; > @@ -1296,6 +1302,10 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) > return IOU_OK; > } > > + if (zc->len != UINT_MAX) { > + io_req_set_res(req, ret, 0); > + return IOU_OK; > + } > if (issue_flags & IO_URING_F_MULTISHOT) > return IOU_ISSUE_SKIP_COMPLETE; > return -EAGAIN; > diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c > index ea099f746599..834c887743c8 100644 > --- a/io_uring/zcrx.c > +++ b/io_uring/zcrx.c > @@ -106,6 +106,7 @@ struct io_zcrx_args { > struct io_zcrx_ifq *ifq; > struct socket *sock; > unsigned nr_skbs; > + unsigned long len; > }; > > static const struct memory_provider_ops io_uring_pp_zc_ops; > @@ -826,6 +827,10 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, > int i, copy, end, off; > int ret = 0; > > + if (args->len == 0) > + return -EINTR; > + len = (args->len != UINT_MAX) ? min_t(size_t, len, args->len) : len; Just min? > + > if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) > return -EAGAIN; > > @@ -920,17 +925,21 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, > out: > if (offset == start_off) > return ret; > + args->len -= (offset - start_off); Doesn't it unconditionally change the magic value UINT_MAX you're trying to preserve? > + if (args->len == 0) > + desc->count = 0; > return offset - start_off; > } > > static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, > struct sock *sk, int flags, > - unsigned issue_flags) > + unsigned issue_flags, unsigned long len) > { > struct io_zcrx_args args = { > .req = req, > .ifq = ifq, > .sock = sk->sk_socket, > + .len = len, > }; > read_descriptor_t rd_desc = { > .count = 1, > @@ -956,6 +965,8 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, > ret = IOU_REQUEUE; > } else if (sock_flag(sk, SOCK_DONE)) { > /* Make it to retry until it finally gets 0. */ > + if (len != UINT_MAX) > + goto out; > if (issue_flags & IO_URING_F_MULTISHOT) > ret = IOU_REQUEUE; > else
On 2025-02-20 05:45, Pavel Begunkov wrote: > On 2/18/25 16:57, David Wei wrote: >> Currently only multishot recvzc requests are supported, but sometimes >> there is a need to do a single recv e.g. peeking at some data in the >> socket. Add single shot recvzc requests where IORING_RECV_MULTISHOT is >> _not_ set and the sqe->len field is set to the number of bytes to read >> N. >> >> There could be multiple completions containing data, like the multishot >> case, since N bytes could be split across multiple frags. This is >> followed by a final completion with res and cflags both set to 0 that >> indicate the completion of the request, or a -res that indicate an >> error. >> >> Signed-off-by: David Wei <dw@davidwei.uk> >> --- >> io_uring/net.c | 26 ++++++++++++++++++-------- >> io_uring/zcrx.c | 17 ++++++++++++++--- >> io_uring/zcrx.h | 2 +- >> 3 files changed, 33 insertions(+), 12 deletions(-) >> >> diff --git a/io_uring/net.c b/io_uring/net.c >> index 000dc70d08d0..d3a9aaa52a13 100644 >> --- a/io_uring/net.c >> +++ b/io_uring/net.c >> @@ -94,6 +94,7 @@ struct io_recvzc { >> struct file *file; >> unsigned msg_flags; >> u16 flags; >> + u32 len; > > Something is up with the types, it's u32, for which you use > UINT_MAX, and later convert to ulong. Inconsistency is my middle name. I'll fix it up. > >> struct io_zcrx_ifq *ifq; >> }; >> > ... >> @@ -1250,6 +1251,9 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) >> zc->ifq = req->ctx->ifq; >> if (!zc->ifq) >> return -EINVAL; >> + zc->len = READ_ONCE(sqe->len); >> + if (zc->len == UINT_MAX) >> + return -EINVAL; >> zc->flags = READ_ONCE(sqe->ioprio); >> zc->msg_flags = READ_ONCE(sqe->msg_flags); >> @@ -1257,12 +1261,14 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) >> return -EINVAL; >> if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)) >> return -EINVAL; >> - /* multishot required */ >> - if (!(zc->flags & IORING_RECV_MULTISHOT)) >> - return -EINVAL; >> - /* All data completions are posted as aux CQEs. */ >> - req->flags |= REQ_F_APOLL_MULTISHOT; >> - >> + if (zc->flags & IORING_RECV_MULTISHOT) { >> + if (zc->len) >> + return -EINVAL; >> + /* All data completions are posted as aux CQEs. */ >> + req->flags |= REQ_F_APOLL_MULTISHOT; > > If you're posting "aux" cqes you have to set the flag for > synchronisation reasons. We probably can split out a "I want to post > aux cqes" flag, but it seems like you don't actually care about > multishot here but limiting the length, or limiting the length + nowait. Yeah, it's still "multishot" because there are still aux cqes for data notifications. The requested N bytes could be in multiple frags. I'll make sure REQ_F_APOLL_MULTISHOT is set. > >> + } >> + if (!zc->len) >> + zc->len = UINT_MAX; >> return 0; >> } >> @@ -1281,7 +1287,7 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) >> return -ENOTSOCK; >> ret = io_zcrx_recv(req, zc->ifq, sock, zc->msg_flags | MSG_DONTWAIT, >> - issue_flags); >> + issue_flags, zc->len); >> if (unlikely(ret <= 0) && ret != -EAGAIN) { >> if (ret == -ERESTARTSYS) >> ret = -EINTR; >> @@ -1296,6 +1302,10 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) >> return IOU_OK; >> } >> + if (zc->len != UINT_MAX) { >> + io_req_set_res(req, ret, 0); >> + return IOU_OK; >> + } >> if (issue_flags & IO_URING_F_MULTISHOT) >> return IOU_ISSUE_SKIP_COMPLETE; >> return -EAGAIN; >> diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c >> index ea099f746599..834c887743c8 100644 >> --- a/io_uring/zcrx.c >> +++ b/io_uring/zcrx.c >> @@ -106,6 +106,7 @@ struct io_zcrx_args { >> struct io_zcrx_ifq *ifq; >> struct socket *sock; >> unsigned nr_skbs; >> + unsigned long len; >> }; >> static const struct memory_provider_ops io_uring_pp_zc_ops; >> @@ -826,6 +827,10 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, >> int i, copy, end, off; >> int ret = 0; >> + if (args->len == 0) >> + return -EINTR; >> + len = (args->len != UINT_MAX) ? min_t(size_t, len, args->len) : len; > > Just min? Yes :facepalm: > >> + >> if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) >> return -EAGAIN; >> @@ -920,17 +925,21 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, >> out: >> if (offset == start_off) >> return ret; >> + args->len -= (offset - start_off); > > Doesn't it unconditionally change the magic value UINT_MAX > you're trying to preserve? Yes, you're right. I will fix this and add a test case. > >> + if (args->len == 0) >> + desc->count = 0; >> return offset - start_off; >> } >> static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, >> struct sock *sk, int flags, >> - unsigned issue_flags) >> + unsigned issue_flags, unsigned long len) >> { >> struct io_zcrx_args args = { >> .req = req, >> .ifq = ifq, >> .sock = sk->sk_socket, >> + .len = len, >> }; >> read_descriptor_t rd_desc = { >> .count = 1, >> @@ -956,6 +965,8 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, >> ret = IOU_REQUEUE; >> } else if (sock_flag(sk, SOCK_DONE)) { >> /* Make it to retry until it finally gets 0. */ >> + if (len != UINT_MAX) >> + goto out; >> if (issue_flags & IO_URING_F_MULTISHOT) >> ret = IOU_REQUEUE; >> else >
diff --git a/io_uring/net.c b/io_uring/net.c index 000dc70d08d0..d3a9aaa52a13 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -94,6 +94,7 @@ struct io_recvzc { struct file *file; unsigned msg_flags; u16 flags; + u32 len; struct io_zcrx_ifq *ifq; }; @@ -1241,7 +1242,7 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) unsigned ifq_idx; if (unlikely(sqe->file_index || sqe->addr2 || sqe->addr || - sqe->len || sqe->addr3)) + sqe->addr3)) return -EINVAL; ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx); @@ -1250,6 +1251,9 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) zc->ifq = req->ctx->ifq; if (!zc->ifq) return -EINVAL; + zc->len = READ_ONCE(sqe->len); + if (zc->len == UINT_MAX) + return -EINVAL; zc->flags = READ_ONCE(sqe->ioprio); zc->msg_flags = READ_ONCE(sqe->msg_flags); @@ -1257,12 +1261,14 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return -EINVAL; if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)) return -EINVAL; - /* multishot required */ - if (!(zc->flags & IORING_RECV_MULTISHOT)) - return -EINVAL; - /* All data completions are posted as aux CQEs. */ - req->flags |= REQ_F_APOLL_MULTISHOT; - + if (zc->flags & IORING_RECV_MULTISHOT) { + if (zc->len) + return -EINVAL; + /* All data completions are posted as aux CQEs. */ + req->flags |= REQ_F_APOLL_MULTISHOT; + } + if (!zc->len) + zc->len = UINT_MAX; return 0; } @@ -1281,7 +1287,7 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) return -ENOTSOCK; ret = io_zcrx_recv(req, zc->ifq, sock, zc->msg_flags | MSG_DONTWAIT, - issue_flags); + issue_flags, zc->len); if (unlikely(ret <= 0) && ret != -EAGAIN) { if (ret == -ERESTARTSYS) ret = -EINTR; @@ -1296,6 +1302,10 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags) return IOU_OK; } + if (zc->len != UINT_MAX) { + io_req_set_res(req, ret, 0); + return IOU_OK; + } if (issue_flags & IO_URING_F_MULTISHOT) return IOU_ISSUE_SKIP_COMPLETE; return -EAGAIN; diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index ea099f746599..834c887743c8 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -106,6 +106,7 @@ struct io_zcrx_args { struct io_zcrx_ifq *ifq; struct socket *sock; unsigned nr_skbs; + unsigned long len; }; static const struct memory_provider_ops io_uring_pp_zc_ops; @@ -826,6 +827,10 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, int i, copy, end, off; int ret = 0; + if (args->len == 0) + return -EINTR; + len = (args->len != UINT_MAX) ? min_t(size_t, len, args->len) : len; + if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) return -EAGAIN; @@ -920,17 +925,21 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, out: if (offset == start_off) return ret; + args->len -= (offset - start_off); + if (args->len == 0) + desc->count = 0; return offset - start_off; } static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, struct sock *sk, int flags, - unsigned issue_flags) + unsigned issue_flags, unsigned long len) { struct io_zcrx_args args = { .req = req, .ifq = ifq, .sock = sk->sk_socket, + .len = len, }; read_descriptor_t rd_desc = { .count = 1, @@ -956,6 +965,8 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, ret = IOU_REQUEUE; } else if (sock_flag(sk, SOCK_DONE)) { /* Make it to retry until it finally gets 0. */ + if (len != UINT_MAX) + goto out; if (issue_flags & IO_URING_F_MULTISHOT) ret = IOU_REQUEUE; else @@ -968,7 +979,7 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, struct socket *sock, unsigned int flags, - unsigned issue_flags) + unsigned issue_flags, unsigned long len) { struct sock *sk = sock->sk; const struct proto *prot = READ_ONCE(sk->sk_prot); @@ -977,7 +988,7 @@ int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, return -EPROTONOSUPPORT; sock_rps_record_flow(sk); - return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags); + return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags, len); } #include <linux/io_uring/net.h> diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h index a16bdd921f03..85da6a14543f 100644 --- a/io_uring/zcrx.h +++ b/io_uring/zcrx.h @@ -46,7 +46,7 @@ void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx); void io_shutdown_zcrx_ifqs(struct io_ring_ctx *ctx); int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, struct socket *sock, unsigned int flags, - unsigned issue_flags); + unsigned issue_flags, unsigned long len); #else static inline int io_register_zcrx_ifq(struct io_ring_ctx *ctx, struct io_uring_zcrx_ifq_reg __user *arg)
Currently only multishot recvzc requests are supported, but sometimes there is a need to do a single recv e.g. peeking at some data in the socket. Add single shot recvzc requests where IORING_RECV_MULTISHOT is _not_ set and the sqe->len field is set to the number of bytes to read N. There could be multiple completions containing data, like the multishot case, since N bytes could be split across multiple frags. This is followed by a final completion with res and cflags both set to 0 that indicate the completion of the request, or a -res that indicate an error. Signed-off-by: David Wei <dw@davidwei.uk> --- io_uring/net.c | 26 ++++++++++++++++++-------- io_uring/zcrx.c | 17 ++++++++++++++--- io_uring/zcrx.h | 2 +- 3 files changed, 33 insertions(+), 12 deletions(-)