io_uring_prep_writev_fixed(3)   liburing Manual  io_uring_prep_writev_fixed(3)

NAME
       io_uring_prep_writev_fixed - prepare a vectored write using fixed
       buffers

SYNOPSIS
       #include <liburing.h>

       void io_uring_prep_writev_fixed(struct io_uring_sqe *sqe,
                                       int fd,
                                       const struct iovec *iovecs,
                                       unsigned nr_vecs,
                                       __u64 offset,
                                       int flags,
                                       int buf_index);

DESCRIPTION
       The io_uring_prep_writev_fixed(3) function prepares a vectored write
       request using fixed (registered) buffers.  The submission queue entry
       sqe is setup to use the file descriptor fd to start writing nr_vecs
       iovecs from the file position offset.

       The iovecs argument points to an array of iovec structures describing
       the write buffers. All buffers must be part of the registered buffer
       set at index buf_index, previously registered with
       io_uring_register_buffers(3).

       The flags argument can contain any per-request flags, such as
       RWF_APPEND or other flags supported by pwritev2(2).

       Using fixed buffers avoids the overhead of mapping buffers for each I/O
       operation, improving performance for applications that reuse the same
       buffers.


RETURN VALUE
       None

ERRORS
       The CQE res field will contain the result of the operation, the number
       of bytes written on success. On error, a negative errno value is
       returned.

SEE ALSO
       io_uring_get_sqe(3), io_uring_submit(3), io_uring_prep_writev(3),
       io_uring_prep_writev2(3), io_uring_prep_write_fixed(3),
       io_uring_prep_readv_fixed(3), io_uring_register_buffers(3)

liburing-2.10                  January 18, 2025  io_uring_prep_writev_fixed(3)