io_uring_prep_fadvise - Man Page

prepare a fadvise request

Synopsis

#include <fcntl.h>
#include <liburing.h>

void io_uring_prep_fadvise(struct io_uring_sqe *sqe,
                           int fd,
                           __u64 offset,
                           __u32 len,
                           int advice);

void io_uring_prep_fadvise64(struct io_uring_sqe *sqe,
                             int fd,
                             __u64 offset,
                             __u64 len,
                             int advice);

Description

The io_uring_prep_fadvise(3) function prepares an fadvise request. The submission queue entry sqe is setup to use the file descriptor pointed to by fd to start an fadvise operation at offset and of len length in bytes, giving it the advise located in advice.

The io_uring_prep_fadvise64(3) function works like io_uring_prep_fadvise(3) except that it takes a 64-bit length rather than just a 32-bit one. Older kernels may not support the 64-bit length variant. If this variant is attempted used on a kernel that doesn't support 64-bit lengths, then the request will get errored with -EINVAL in the results field of the CQE.

This function prepares an async posix_fadvise(2) request. See that man page for details.

Return Value

None

Errors

The CQE res field will contain the result of the operation. See the related man page for details on possible values. Note that where synchronous system calls will return -1 on failure and set errno to the actual error value, io_uring never uses errno. Instead it returns the negated errno directly in the CQE res field.

See Also

io_uring_get_sqe(3), io_uring_submit(3), io_uring_register(2), posix_fadvise(2)

Referenced By

The man page io_uring_prep_fadvise64(3) is an alias of io_uring_prep_fadvise(3).

March 13, 2022 liburing-2.2 liburing Manual