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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-01 17:35:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-01 17:35:47 -0700
commit193bc55b6d4e0a7b4ad0216ed9794252bee6436e (patch)
treed99d1b440d3a143bf986dc10d54d5302e7b5cabf /lib
parent668f1e9267415153e30bea03828c0530874e92e4 (diff)
parent7e934cf5ace1dceeb804f7493fa28bb697ed3c52 (diff)
downloadlinux-193bc55b6d4e0a7b4ad0216ed9794252bee6436e.tar.gz
Merge tag 'xarray-5.7' of git://git.infradead.org/users/willy/linux-dax
Pull XArray updates from Matthew Wilcox:

 - Fix two bugs which affected multi-index entries larger than 2^26
   indices

 - Fix some documentation

 - Remove unused IDA macros

 - Add a small optimisation for tiny configurations

 - Fix a bug which could cause an RCU walker to terminate a marked walk
   early

* tag 'xarray-5.7' of git://git.infradead.org/users/willy/linux-dax:
  xarray: Fix early termination of xas_for_each_marked
  radix tree test suite: Support kmem_cache alignment
  XArray: Optimise xas_sibling() if !CONFIG_XARRAY_MULTI
  ida: remove abandoned macros
  XArray: Fix incorrect comment in header file
  XArray: Fix xas_pause for large multi-index entries
  XArray: Fix xa_find_next for large multi-index entries
Diffstat (limited to 'lib')
-rw-r--r--lib/radix-tree.c8
-rw-r--r--lib/test_xarray.c55
-rw-r--r--lib/xarray.c9
3 files changed, 61 insertions, 11 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index c8fa1d274530..2ee6ae3b0ade 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -56,14 +56,6 @@ struct kmem_cache *radix_tree_node_cachep;
 #define IDR_PRELOAD_SIZE	(IDR_MAX_PATH * 2 - 1)
 
 /*
- * The IDA is even shorter since it uses a bitmap at the last level.
- */
-#define IDA_INDEX_BITS		(8 * sizeof(int) - 1 - ilog2(IDA_BITMAP_BITS))
-#define IDA_MAX_PATH		(DIV_ROUND_UP(IDA_INDEX_BITS, \
-						RADIX_TREE_MAP_SHIFT))
-#define IDA_PRELOAD_SIZE	(IDA_MAX_PATH * 2 - 1)
-
-/*
  * Per-cpu pool of preloaded nodes
  */
 struct radix_tree_preload {
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 55c14e8c8859..d4f97925dbd8 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -12,6 +12,9 @@
 static unsigned int tests_run;
 static unsigned int tests_passed;
 
+static const unsigned int order_limit =
+		IS_ENABLED(CONFIG_XARRAY_MULTI) ? BITS_PER_LONG : 1;
+
 #ifndef XA_DEBUG
 # ifdef __KERNEL__
 void xa_dump(const struct xarray *xa) { }
@@ -959,6 +962,20 @@ static noinline void check_multi_find_2(struct xarray *xa)
 	}
 }
 
+static noinline void check_multi_find_3(struct xarray *xa)
+{
+	unsigned int order;
+
+	for (order = 5; order < order_limit; order++) {
+		unsigned long index = 1UL << (order - 5);
+
+		XA_BUG_ON(xa, !xa_empty(xa));
+		xa_store_order(xa, 0, order - 4, xa_mk_index(0), GFP_KERNEL);
+		XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT));
+		xa_erase_index(xa, 0);
+	}
+}
+
 static noinline void check_find_1(struct xarray *xa)
 {
 	unsigned long i, j, k;
@@ -1081,6 +1098,7 @@ static noinline void check_find(struct xarray *xa)
 	for (i = 2; i < 10; i++)
 		check_multi_find_1(xa, i);
 	check_multi_find_2(xa);
+	check_multi_find_3(xa);
 }
 
 /* See find_swap_entry() in mm/shmem.c */
@@ -1138,6 +1156,42 @@ static noinline void check_find_entry(struct xarray *xa)
 	XA_BUG_ON(xa, !xa_empty(xa));
 }
 
+static noinline void check_pause(struct xarray *xa)
+{
+	XA_STATE(xas, xa, 0);
+	void *entry;
+	unsigned int order;
+	unsigned long index = 1;
+	unsigned int count = 0;
+
+	for (order = 0; order < order_limit; order++) {
+		XA_BUG_ON(xa, xa_store_order(xa, index, order,
+					xa_mk_index(index), GFP_KERNEL));
+		index += 1UL << order;
+	}
+
+	rcu_read_lock();
+	xas_for_each(&xas, entry, ULONG_MAX) {
+		XA_BUG_ON(xa, entry != xa_mk_index(1UL << count));
+		count++;
+	}
+	rcu_read_unlock();
+	XA_BUG_ON(xa, count != order_limit);
+
+	count = 0;
+	xas_set(&xas, 0);
+	rcu_read_lock();
+	xas_for_each(&xas, entry, ULONG_MAX) {
+		XA_BUG_ON(xa, entry != xa_mk_index(1UL << count));
+		count++;
+		xas_pause(&xas);
+	}
+	rcu_read_unlock();
+	XA_BUG_ON(xa, count != order_limit);
+
+	xa_destroy(xa);
+}
+
 static noinline void check_move_tiny(struct xarray *xa)
 {
 	XA_STATE(xas, xa, 0);
@@ -1646,6 +1700,7 @@ static int xarray_checks(void)
 	check_xa_alloc();
 	check_find(&array);
 	check_find_entry(&array);
+	check_pause(&array);
 	check_account(&array);
 	check_destroy(&array);
 	check_move(&array);
diff --git a/lib/xarray.c b/lib/xarray.c
index 1d9fab7db8da..e9e641d3c0c3 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -970,7 +970,7 @@ void xas_pause(struct xa_state *xas)
 
 	xas->xa_node = XAS_RESTART;
 	if (node) {
-		unsigned int offset = xas->xa_offset;
+		unsigned long offset = xas->xa_offset;
 		while (++offset < XA_CHUNK_SIZE) {
 			if (!xa_is_sibling(xa_entry(xas->xa, node, offset)))
 				break;
@@ -1208,6 +1208,8 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
 		}
 
 		entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
+		if (!entry && !(xa_track_free(xas->xa) && mark == XA_FREE_MARK))
+			continue;
 		if (!xa_is_node(entry))
 			return entry;
 		xas->xa_node = xa_to_node(entry);
@@ -1836,10 +1838,11 @@ static bool xas_sibling(struct xa_state *xas)
 	struct xa_node *node = xas->xa_node;
 	unsigned long mask;
 
-	if (!node)
+	if (!IS_ENABLED(CONFIG_XARRAY_MULTI) || !node)
 		return false;
 	mask = (XA_CHUNK_SIZE << node->shift) - 1;
-	return (xas->xa_index & mask) > (xas->xa_offset << node->shift);
+	return (xas->xa_index & mask) >
+		((unsigned long)xas->xa_offset << node->shift);
 }
 
 /**