idr: Remove idr_alloc_ext

It has no more users, so remove it.  Move idr_alloc() back into idr.c,
move the guts of idr_alloc_cmn() into idr_alloc_u32(), remove the
wrappers around idr_get_free_cmn() and rename it to idr_get_free().
While there is now no interface to allocate IDs larger than a u32,
the IDR internals remain ready to handle a larger ID should a need arise.

These changes make it possible to provide the guarantee that, if the
nextid pointer points into the object, the object's ID will be initialised
before a concurrent lookup can find the object.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c
index 892ef8855b02..36437ade429c 100644
--- a/tools/testing/radix-tree/idr-test.c
+++ b/tools/testing/radix-tree/idr-test.c
@@ -215,6 +215,23 @@ void idr_checks(void)
 
 	assert(idr_is_empty(&idr));
 
+	idr_set_cursor(&idr, INT_MAX - 3UL);
+	for (i = INT_MAX - 3UL; i < INT_MAX + 3UL; i++) {
+		struct item *item;
+		unsigned int id;
+		if (i <= INT_MAX)
+			item = item_create(i, 0);
+		else
+			item = item_create(i - INT_MAX - 1, 0);
+
+		id = idr_alloc_cyclic(&idr, item, 0, 0, GFP_KERNEL);
+		assert(id == item->index);
+	}
+
+	idr_for_each(&idr, item_idr_free, &idr);
+	idr_destroy(&idr);
+	assert(idr_is_empty(&idr));
+
 	for (i = 1; i < 10000; i++) {
 		struct item *item = item_create(i, 0);
 		assert(idr_alloc(&idr, item, 1, 20000, GFP_KERNEL) == i);