diff options
Diffstat (limited to 'include/linux/idr.h')
| -rw-r--r-- | include/linux/idr.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index 9a2d762124d..fa035f96f2a 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -15,6 +15,7 @@ #include <linux/types.h> #include <linux/bitops.h> #include <linux/init.h> +#include <linux/rcupdate.h> #if BITS_PER_LONG == 32 # define IDR_BITS 5 @@ -51,6 +52,7 @@ struct idr_layer { unsigned long bitmap; /* A zero bit means "space here" */ struct idr_layer *ary[1<<IDR_BITS]; int count; /* When zero, we can release it */ + struct rcu_head rcu_head; }; struct idr { @@ -71,6 +73,28 @@ struct idr { } #define DEFINE_IDR(name) struct idr name = IDR_INIT(name) +/* Actions to be taken after a call to _idr_sub_alloc */ +#define IDR_NEED_TO_GROW -2 +#define IDR_NOMORE_SPACE -3 + +#define _idr_rc_to_errno(rc) ((rc) == -1 ? -EAGAIN : -ENOSPC) + +/** + * idr synchronization (stolen from radix-tree.h) + * + * idr_find() is able to be called locklessly, using RCU. The caller must + * ensure calls to this function are made within rcu_read_lock() regions. + * Other readers (lock-free or otherwise) and modifications may be running + * concurrently. + * + * It is still required that the caller manage the synchronization and + * lifetimes of the items. So if RCU lock-free lookups are used, typically + * this would mean that the items have their own locks, or are amenable to + * lock-free access; and that the items are freed by RCU (or only freed after + * having been deleted from the idr tree *and* a synchronize_rcu() grace + * period). + */ + /* * This is what we export. */ |