idr_alloc — allocate new idr entry
int idr_alloc ( | struct idr * idr, |
| void * ptr, | |
| int start, | |
| int end, | |
gfp_t gfp_mask); |
idrthe (initialized) idr
ptrpointer to be associated with the new id
startthe minimum id (inclusive)
endthe maximum id (exclusive, <= 0 for max)
gfp_maskmemory allocation flags
Allocate an id in [start, end) and associate it with ptr. If no ID is
available in the specified range, returns -ENOSPC. On memory allocation
failure, returns -ENOMEM.
Note that end is treated as max when <= 0. This is to always allow
using start + N as end as long as N is inside integer range.
The user is responsible for exclusively synchronizing all operations
which may modify idr. However, read-only accesses such as idr_find
or iteration can be performed under RCU read lock provided the user
destroys ptr in RCU-safe way after removal from idr.