io_uring: rethink def->needs_async_data

needs_async_data controls allocation of async_data, and used in two
cases. 1) when async setup requires it (by io_req_prep_async() or
handler themselves), and 2) when op always needs additional space to
operate, like timeouts do.

Opcode preps already don't bother about the second case and do
allocation unconditionally, restrict needs_async_data to the first case
only and rename it into needs_async_setup.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
[axboe: update for IOPOLL fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index e4589382365266377c9cb4b425266ccf7867a7bc..4df9961d6245d17fffecff777c49a815082a90b9 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -849,8 +849,8 @@ struct io_op_def {
        unsigned                pollout : 1;
        /* op supports buffer selection */
        unsigned                buffer_select : 1;
-       /* must always have async data allocated */
-       unsigned                needs_async_data : 1;
+       /* do prep async if is going to be punted */
+       unsigned                needs_async_setup : 1;
        /* should block plug */
        unsigned                plug : 1;
        /* size of async data needed, if any */
@@ -864,7 +864,7 @@ static const struct io_op_def io_op_defs[] = {
                .unbound_nonreg_file    = 1,
                .pollin                 = 1,
                .buffer_select          = 1,
-               .needs_async_data       = 1,
+               .needs_async_setup      = 1,
                .plug                   = 1,
                .async_size             = sizeof(struct io_async_rw),
        },
@@ -873,7 +873,7 @@ static const struct io_op_def io_op_defs[] = {
                .hash_reg_file          = 1,
                .unbound_nonreg_file    = 1,
                .pollout                = 1,
-               .needs_async_data       = 1,
+               .needs_async_setup      = 1,
                .plug                   = 1,
                .async_size             = sizeof(struct io_async_rw),
        },
@@ -907,7 +907,7 @@ static const struct io_op_def io_op_defs[] = {
                .needs_file             = 1,
                .unbound_nonreg_file    = 1,
                .pollout                = 1,
-               .needs_async_data       = 1,
+               .needs_async_setup      = 1,
                .async_size             = sizeof(struct io_async_msghdr),
        },
        [IORING_OP_RECVMSG] = {
@@ -915,11 +915,10 @@ static const struct io_op_def io_op_defs[] = {
                .unbound_nonreg_file    = 1,
                .pollin                 = 1,
                .buffer_select          = 1,
-               .needs_async_data       = 1,
+               .needs_async_setup      = 1,
                .async_size             = sizeof(struct io_async_msghdr),
        },
        [IORING_OP_TIMEOUT] = {
-               .needs_async_data       = 1,
                .async_size             = sizeof(struct io_timeout_data),
        },
        [IORING_OP_TIMEOUT_REMOVE] = {
@@ -932,14 +931,13 @@ static const struct io_op_def io_op_defs[] = {
        },
        [IORING_OP_ASYNC_CANCEL] = {},
        [IORING_OP_LINK_TIMEOUT] = {
-               .needs_async_data       = 1,
                .async_size             = sizeof(struct io_timeout_data),
        },
        [IORING_OP_CONNECT] = {
                .needs_file             = 1,
                .unbound_nonreg_file    = 1,
                .pollout                = 1,
-               .needs_async_data       = 1,
+               .needs_async_setup      = 1,
                .async_size             = sizeof(struct io_async_connect),
        },
        [IORING_OP_FALLOCATE] = {
@@ -3139,7 +3137,7 @@ static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
                             const struct iovec *fast_iov,
                             struct iov_iter *iter, bool force)
 {
-       if (!force && !io_op_defs[req->opcode].needs_async_data)
+       if (!force && !io_op_defs[req->opcode].needs_async_setup)
                return 0;
        if (!req->async_data) {
                if (io_alloc_async_data(req)) {
@@ -5872,12 +5870,8 @@ static int io_req_prep_async(struct io_kiocb *req)
 {
        switch (req->opcode) {
        case IORING_OP_READV:
-       case IORING_OP_READ_FIXED:
-       case IORING_OP_READ:
                return io_rw_prep_async(req, READ);
        case IORING_OP_WRITEV:
-       case IORING_OP_WRITE_FIXED:
-       case IORING_OP_WRITE:
                return io_rw_prep_async(req, WRITE);
        case IORING_OP_SENDMSG:
                return io_sendmsg_prep_async(req);
@@ -5891,11 +5885,10 @@ static int io_req_prep_async(struct io_kiocb *req)
 
 static int io_req_defer_prep(struct io_kiocb *req)
 {
-       if (!io_op_defs[req->opcode].needs_async_data)
-               return 0;
-       /* some opcodes init it during the inital prep */
-       if (req->async_data)
+       if (!io_op_defs[req->opcode].needs_async_setup)
                return 0;
+       if (WARN_ON_ONCE(req->async_data))
+               return -EFAULT;
        if (io_alloc_async_data(req))
                return -EAGAIN;
        return io_req_prep_async(req);