1IDR_ALLOC(9)            Basic Kernel Library Functions            IDR_ALLOC(9)
2
3
4

NAME

6       idr_alloc - allocate new idr entry
7

SYNOPSIS

9       int idr_alloc(struct idr * idr, void * ptr, int start, int end,
10                     gfp_t gfp_mask);
11

ARGUMENTS

13       idr
14           the (initialized) idr
15
16       ptr
17           pointer to be associated with the new id
18
19       start
20           the minimum id (inclusive)
21
22       end
23           the maximum id (exclusive, <= 0 for max)
24
25       gfp_mask
26           memory allocation flags
27

DESCRIPTION

29       Allocate an id in [start, end) and associate it with ptr. If no ID is
30       available in the specified range, returns -ENOSPC. On memory allocation
31       failure, returns -ENOMEM.
32
33       Note that end is treated as max when <= 0. This is to always allow
34       using start + N as end as long as N is inside integer range.
35
36       The user is responsible for exclusively synchronizing all operations
37       which may modify idr. However, read-only accesses such as idr_find or
38       iteration can be performed under RCU read lock provided the user
39       destroys ptr in RCU-safe way after removal from idr.
40

42Kernel Hackers Manual 3.10         June 2019                      IDR_ALLOC(9)
Impressum