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Diffstat (limited to 'man/io_uring_prep_write_fixed.3')
-rw-r--r-- | man/io_uring_prep_write_fixed.3 | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/man/io_uring_prep_write_fixed.3 b/man/io_uring_prep_write_fixed.3 new file mode 100644 index 0000000..5dab4a6 --- /dev/null +++ b/man/io_uring_prep_write_fixed.3 @@ -0,0 +1,72 @@ +.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk> +.\" +.\" SPDX-License-Identifier: LGPL-2.0-or-later +.\" +.TH io_uring_prep_write 3 "February 13, 2022" "liburing-2.1" "liburing Manual" +.SH NAME +io_uring_prep_write_fixed \- prepare I/O write request with registered buffer +.SH SYNOPSIS +.nf +.B #include <liburing.h> +.PP +.BI "void io_uring_prep_write_fixed(struct io_uring_sqe *" sqe "," +.BI " int " fd ", +.BI " const void *" buf "," +.BI " unsigned " nbytes "," +.BI " __u64 " offset "," +.BI " int " buf_index ");" +.fi +.SH DESCRIPTION +.PP +The +.BR io_uring_prep_write_fixed (3) +prepares an IO write request with a previously registered IO buffer. The +submission queue entry +.I sqe +is setup to use the file descriptor +.I fd +to start writing +.I nbytes +from the buffer +.I buf +at the specified +.I offset +and with the buffer matching the registered index of +.IR buf_index . + +This works just like +.BR io_uring_prep_write (3) +except it requires the use of buffers that have been registered with +.BR io_uring_register_buffers (3). +The +.I buf +and +.I nbytes +arguments must fall within a region specificed by +.I buf_index +in the previously registered buffer. The buffer need not be aligned with +the start of the registered buffer. + +After the read has been prepared it can be submitted with one of the submit +functions. + +.SH RETURN VALUE +None +.SH ERRORS +The CQE +.I 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 +.B -1 +on failure and set +.I errno +to the actual error value, io_uring never uses +.IR errno . +Instead it returns the negated +.I errno +directly in the CQE +.I res +field. +.SH SEE ALSO +.BR io_uring_prep_write (3), +.BR io_uring_register_buffers (3) |