idr: deprecate idr_remove_all()

[~andy/linux] / lib / idr.c

diff --git a/lib/idr.c b/lib/idr.c
index 648239079dd21329f0329ddaf12552677149d846..814c53ce0d41a54dc535cc4a10e847398a3bcf97 100644 (file)
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -433,20 +433,7 @@ void idr_remove(struct idr *idp, int id)
 }
 EXPORT_SYMBOL(idr_remove);
 
-/**
- * idr_remove_all - remove all ids from the given idr tree
- * @idp: idr handle
- *
- * idr_destroy() only frees up unused, cached idp_layers, but this
- * function will remove all id mappings and leave all idp_layers
- * unused.
- *
- * A typical clean-up sequence for objects stored in an idr tree will
- * use idr_for_each() to free all objects, if necessay, then
- * idr_remove_all() to remove all ids, and idr_destroy() to free
- * up the cached idr_layers.
- */
-void idr_remove_all(struct idr *idp)
+void __idr_remove_all(struct idr *idp)
 {
        int n, id, max;
        int bt_mask;
@@ -479,14 +466,25 @@ void idr_remove_all(struct idr *idp)
        }
        idp->layers = 0;
 }
-EXPORT_SYMBOL(idr_remove_all);
+EXPORT_SYMBOL(__idr_remove_all);
 
 /**
  * idr_destroy - release all cached layers within an idr tree
  * @idp: idr handle
+ *
+ * Free all id mappings and all idp_layers.  After this function, @idp is
+ * completely unused and can be freed / recycled.  The caller is
+ * responsible for ensuring that no one else accesses @idp during or after
+ * idr_destroy().
+ *
+ * A typical clean-up sequence for objects stored in an idr tree will use
+ * idr_for_each() to free all objects, if necessay, then idr_destroy() to
+ * free up the id mappings and cached idr_layers.
  */
 void idr_destroy(struct idr *idp)
 {
+       __idr_remove_all(idp);
+
        while (idp->id_free_cnt) {
                struct idr_layer *p = get_from_free_list(idp);
                kmem_cache_free(idr_layer_cache, p);
@@ -625,7 +623,14 @@ void *idr_get_next(struct idr *idp, int *nextidp)
                        return p;
                }
 
-               id += 1 << n;
+               /*
+                * Proceed to the next layer at the current level.  Unlike
+                * idr_for_each(), @id isn't guaranteed to be aligned to
+                * layer boundary at this point and adding 1 << n may
+                * incorrectly skip IDs.  Make sure we jump to the
+                * beginning of the next layer using round_up().
+                */
+               id = round_up(id + 1, 1 << n);
                while (n < fls(id)) {
                        n += IDR_BITS;
                        p = *--paa;