diff options
author | Stefan Metzmacher <metze@samba.org> | 2021-03-20 22:33:36 +0300 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2021-03-21 18:41:14 +0300 |
commit | 0031275d119efe16711cd93519b595e6f9b4b330 (patch) | |
tree | c10e02cdb624d018a3120f91e1eaed2692bb0689 | |
parent | 00ddff431a458bbf143ea7c4c42d022676da1b17 (diff) | |
download | linux-0031275d119efe16711cd93519b595e6f9b4b330.tar.xz |
io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with MSG_WAITALL
Without that it's not safe to use them in a linked combination with
others.
Now combinations like IORING_OP_SENDMSG followed by IORING_OP_SPLICE
should be possible.
We already handle short reads and writes for the following opcodes:
- IORING_OP_READV
- IORING_OP_READ_FIXED
- IORING_OP_READ
- IORING_OP_WRITEV
- IORING_OP_WRITE_FIXED
- IORING_OP_WRITE
- IORING_OP_SPLICE
- IORING_OP_TEE
Now we have it for these as well:
- IORING_OP_SENDMSG
- IORING_OP_SEND
- IORING_OP_RECVMSG
- IORING_OP_RECV
For IORING_OP_RECVMSG we also check for the MSG_TRUNC and MSG_CTRUNC
flags in order to call req_set_fail_links().
There might be applications arround depending on the behavior
that even short send[msg]()/recv[msg]() retuns continue an
IOSQE_IO_LINK chain.
It's very unlikely that such applications pass in MSG_WAITALL,
which is only defined in 'man 2 recvmsg', but not in 'man 2 sendmsg'.
It's expected that the low level sock_sendmsg() call just ignores
MSG_WAITALL, as MSG_ZEROCOPY is also ignored without explicitly set
SO_ZEROCOPY.
We also expect the caller to know about the implicit truncation to
MAX_RW_COUNT, which we don't detect.
cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/c4e1a4cc0d905314f4d5dc567e65a7b09621aab3.1615908477.git.metze@samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | fs/io_uring.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index ea2d3e120555..543551d70327 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4386,6 +4386,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) struct io_async_msghdr iomsg, *kmsg; struct socket *sock; unsigned flags; + int min_ret = 0; int ret; sock = sock_from_file(req->file); @@ -4406,6 +4407,9 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) else if (issue_flags & IO_URING_F_NONBLOCK) flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) return io_setup_async_msg(req, kmsg); @@ -4416,7 +4420,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) if (kmsg->free_iov) kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; - if (ret < 0) + if (ret < min_ret) req_set_fail_links(req); __io_req_complete(req, issue_flags, ret, 0); return 0; @@ -4429,6 +4433,7 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) struct iovec iov; struct socket *sock; unsigned flags; + int min_ret = 0; int ret; sock = sock_from_file(req->file); @@ -4450,6 +4455,9 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) else if (issue_flags & IO_URING_F_NONBLOCK) flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&msg.msg_iter); + msg.msg_flags = flags; ret = sock_sendmsg(sock, &msg); if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) @@ -4457,7 +4465,7 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) if (ret == -ERESTARTSYS) ret = -EINTR; - if (ret < 0) + if (ret < min_ret) req_set_fail_links(req); __io_req_complete(req, issue_flags, ret, 0); return 0; @@ -4609,6 +4617,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) struct socket *sock; struct io_buffer *kbuf; unsigned flags; + int min_ret = 0; int ret, cflags = 0; bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; @@ -4640,6 +4649,9 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) else if (force_nonblock) flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg, kmsg->uaddr, flags); if (force_nonblock && ret == -EAGAIN) @@ -4653,7 +4665,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) if (kmsg->free_iov) kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; - if (ret < 0) + if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) req_set_fail_links(req); __io_req_complete(req, issue_flags, ret, cflags); return 0; @@ -4668,6 +4680,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) struct socket *sock; struct iovec iov; unsigned flags; + int min_ret = 0; int ret, cflags = 0; bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; @@ -4699,6 +4712,9 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) else if (force_nonblock) flags |= MSG_DONTWAIT; + if (flags & MSG_WAITALL) + min_ret = iov_iter_count(&msg.msg_iter); + ret = sock_recvmsg(sock, &msg, flags); if (force_nonblock && ret == -EAGAIN) return -EAGAIN; @@ -4707,7 +4723,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) out_free: if (req->flags & REQ_F_BUFFER_SELECTED) cflags = io_put_recv_kbuf(req); - if (ret < 0) + if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) req_set_fail_links(req); __io_req_complete(req, issue_flags, ret, cflags); return 0; |