NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | COLOPHON |
|
|
io_uring_prep_msg_ring(3) liburing Manual io_uring_prep_msg_ring(3)
io_uring_prep_msg_ring_fd - send a direct descriptor to another ring
#include <liburing.h> void io_uring_prep_msg_ring_fd(struct io_uring_sqe *sqe, int fd, int source_fd, int target_fd, __u64 data, unsigned int flags); void io_uring_prep_msg_ring_fd_alloc(struct io_uring_sqe *sqe, int fd, int source_fd, __u64 data, unsigned int flags);
io_uring_prep_msg_ring_fd(3) prepares an SQE to send a direct file descriptor to another ring. The submission queue entry sqe is setup to use the file descriptor fd, which must identify a target io_uring context, to send the locally registered file descriptor with value source_fd to the destination ring into index target_fd and passing data as the user data in the target CQE with the request modifier flags set by flags. Currently there are no valid flag modifiers, this field must contain 0. io_uring_prep_msg_ring_fd_alloc(3) is similar to io_uring_prep_msg_ring_fd(3), but doesn't specify a target index for the direct descriptor. Instead, this index is allocated in the target ring and returned in the CQE res field.
None
These are the errors that are reported in the CQE res field. -ENOMEM The kernel was unable to allocate memory for the request. -EINVAL One of the fields set in the SQE was invalid. -EINVAL Target ring is identical to the source ring. -EBADFD The descriptor passed in fd does not refer to an io_uring file descriptor, or the ring is in a disabled state. -EOVERFLOW The kernel was unable to fill a CQE on the target ring. This can happen if the target CQ ring is in an overflow state and the kernel wasn't able to allocate memory for a new CQE entry. -ENFILE The direct descriptor table in the target ring was full, no new descriptors could be successfully allocated.
This page is part of the liburing (A library for io_uring)
project. Information about the project can be found at
⟨https://github.com/axboe/liburing⟩. If you have a bug report for
this manual page, send it to [email protected]. This page
was obtained from the project's upstream Git repository
⟨https://github.com/axboe/liburing⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-03.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
liburing-2.4 Mar 16, 2023 io_uring_prep_msg_ring(3)
Pages that refer to this page: io_uring_prep_msg_ring_fd(3), io_uring_prep_msg_ring_fd_alloc(3)