'\" t
.\"     Title: idr_alloc
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: June 2017
.\"    Manual: Basic Kernel Library Functions
.\"    Source: Kernel Hackers Manual 4.11.3
.\"  Language: English
.\"
.TH "IDR_ALLOC" "9" "June 2017" "Kernel Hackers Manual 4\&.11\&" "Basic Kernel Library Functions"
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.SH "NAME"
idr_alloc \- allocate an id
.SH "SYNOPSIS"
.HP \w'int\ idr_alloc('u
.BI "int idr_alloc(struct\ idr\ *\ " "idr" ", void\ *\ " "ptr" ", int\ " "start" ", int\ " "end" ", gfp_t\ " "gfp" ");"
.SH "ARGUMENTS"
.PP
\fIstruct idr * idr\fR
.RS 4
idr handle
.RE
.PP
\fIvoid * ptr\fR
.RS 4
pointer to be associated with the new id
.RE
.PP
\fIint start\fR
.RS 4
the minimum id (inclusive)
.RE
.PP
\fIint end\fR
.RS 4
the maximum id (exclusive)
.RE
.PP
\fIgfp_t gfp\fR
.RS 4
memory allocation flags
.RE
.SH "DESCRIPTION"
.PP
Allocates an unused ID in the range [start, end)\&. Returns \-ENOSPC if there are no unused IDs in that range\&.
.PP
Note that
\fIend\fR
is treated as max when <= 0\&. This is to always allow using
\fIstart\fR
+ N as
\fIend\fR
as long as N is inside integer range\&.
.PP
Simultaneous modifications to the
\fIidr\fR
are not allowed and should be prevented by the user, usually with a lock\&.
\fBidr_alloc\fR
may be called concurrently with read\-only accesses to the
\fIidr\fR, such as
\fBidr_find\fR
and
\fBidr_for_each_entry\fR\&.
.SH "COPYRIGHT"
.br