Movatterモバイル変換

io_uring_prep_fixed_fd_install(3) — Linux manual page

io_uring_pr..._fd_install(3) liburing Manualio_uring_pr..._fd_install(3)

NAME        top

       io_uring_prep_fixed_fd_install - prepare fixed file fd       installation request

SYNOPSIS        top

#include <liburing.h>void io_uring_prep_fixed_fd_install(struct io_uring_sqe *sqe,intfd,unsigned intflags);

DESCRIPTION        top

       Theio_uring_prep_fixed_fd_install(3) helper prepares a fixed file       descriptor installation. The submission queue entrysqe is setup       to install the direct/fixed file descriptorfd with the specifiedflags file installation flags.       One use case of direct/fixed file descriptors is to turn a regular       file descriptor into a direct one, reducing the overhead of any       request that needs to access this file. This helper provides a way       to go the other way, turning a direct descriptor into a regular       file descriptor that can then subsequently be used by regular       system calls that take a normal file descriptor.  This can be       handy if no regular file descriptor exists for this direct       descriptor. Either because it was instantiated directly as a fixed       descriptor, or because the regular file was closed withclose(2)       after being turned into a direct descriptor.       Upon successful return of this request, both a normal and fixed       file descriptor exists for the same file. Either one of them may       be used to access the file.  Either one of them may be closed       without affecting the other one.flags may be either zero, or set toIORING_FIXED_FD_NO_CLOEXECto       indicate that the new regular file descriptor should not be closed       during exec. By default,O_CLOEXECwill be set on the new       descriptor otherwise. Setting this field to anything but those two       values will result in the request being failed with-EINVALin the       CQEres field.

RETURN VALUE        top

       None

ERRORS        top

       The CQEres field will contain the result of the operation, which       in this case will be the value of the new regular file descriptor.       In case of failure, a negative value is returned.

SEE ALSO        top

io_uring_get_sqe(3),io_uring_submit(3),io_uring_register_files(3),io_uring_unregister_files(3),io_uring_prep_close_direct(3),io_uring_prep_openat_direct(3)

COLOPHON        top

       This page is part of theliburing (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 io-uring@vger.kernel.org.  This page       was obtained from the project's upstream Git repository       ⟨https://github.com/axboe/liburing⟩ on 2025-08-11.  (At that time,       the date of the most recent commit that was found in the       repository was 2025-08-02.)  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 isnot part of the original manual page), send a mail to       man-pages@man7.orgliburing-2.6                 December 8, 2023io_uring_pr..._fd_install(3)

Pages that refer to this page:io_uring_prep_fixed_fd_install(3)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.