ipc: introduce the ipcid_to_idx macro
This is a trivial patch that changes all the (id % SEQ_MULTIPLIER) into a call
to the ipcid_to_idx(id) macro.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/util.c b/ipc/util.c
index 9b0c4e7..c51c96f 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -413,7 +413,7 @@
void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
- int lid = ipcp->id % SEQ_MULTIPLIER;
+ int lid = ipcid_to_idx(ipcp->id);
idr_remove(&ids->ipcs_idr, lid);
@@ -672,7 +672,7 @@
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
- int lid = id % SEQ_MULTIPLIER;
+ int lid = ipcid_to_idx(id);
rcu_read_lock();
out = idr_find(&ids->ipcs_idr, lid);
diff --git a/ipc/util.h b/ipc/util.h
index 2a03d8c..fa7e7a0 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -79,6 +79,8 @@
#define IPC_MSG_IDS 1
#define IPC_SHM_IDS 2
+#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+
/* must be called with ids->mutex acquired.*/
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
int ipc_get_maxid(struct ipc_ids *);
