Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...

[firefly-linux-kernel-4.4.55.git] / include / linux / idr.h

diff --git a/include/linux/idr.h b/include/linux/idr.h
index e968db71e33a94548160cb38c216289ab1577c30..13a801f3d028225533f2ce701349b2b0657ca734 100644 (file)
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -50,14 +50,14 @@
 
 struct idr_layer {
        unsigned long            bitmap; /* A zero bit means "space here" */
-       struct idr_layer        *ary[1<<IDR_BITS];
+       struct idr_layer __rcu  *ary[1<<IDR_BITS];
        int                      count;  /* When zero, we can release it */
        int                      layer;  /* distance from leaf */
        struct rcu_head          rcu_head;
 };
 
 struct idr {
-       struct idr_layer *top;
+       struct idr_layer __rcu *top;
        struct idr_layer *id_free;
        int               layers; /* only valid without concurrent changes */
        int               id_free_cnt;
@@ -81,6 +81,7 @@ struct idr {
 #define _idr_rc_to_errno(rc) ((rc) == -1 ? -EAGAIN : -ENOSPC)
 
 /**
+ * DOC: idr sync
  * idr synchronization (stolen from radix-tree.h)
  *
  * idr_find() is able to be called locklessly, using RCU. The caller must
@@ -117,10 +118,13 @@ void idr_init(struct idr *idp);
 /*
  * IDA - IDR based id allocator, use when translation from id to
  * pointer isn't necessary.
+ *
+ * IDA_BITMAP_LONGS is calculated to be one less to accommodate
+ * ida_bitmap->nr_busy so that the whole struct fits in 128 bytes.
  */
 #define IDA_CHUNK_SIZE         128     /* 128 bytes per chunk */
-#define IDA_BITMAP_LONGS       (128 / sizeof(long) - 1)
-#define IDA_BITMAP_BITS                (IDA_BITMAP_LONGS * sizeof(long) * 8)
+#define IDA_BITMAP_LONGS       (IDA_CHUNK_SIZE / sizeof(long) - 1)
+#define IDA_BITMAP_BITS        (IDA_BITMAP_LONGS * sizeof(long) * 8)
 
 struct ida_bitmap {
        long                    nr_busy;