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authorMatthew Wilcox <willy@infradead.org>2017-12-04 00:11:48 -0500
committerMatthew Wilcox <willy@infradead.org>2018-10-21 10:45:59 -0400
commit2264f5132fe45571139727ebdeb78696b35d1506 (patch)
tree6982c4c48af09fc39c1faf5da5b39c5d4fc41ad0
parent4e99d4e9579d3b950bf4b38d0d64eb1b9be78761 (diff)
downloadlinux-2264f5132fe45571139727ebdeb78696b35d1506.tar.bz2
xarray: Add xas_create_range
This hopefully temporary function is useful for users who have not yet been converted to multi-index entries. Signed-off-by: Matthew Wilcox <willy@infradead.org>
-rw-r--r--include/linux/xarray.h13
-rw-r--r--lib/test_xarray.c119
-rw-r--r--lib/xarray.c50
3 files changed, 182 insertions, 0 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 2664e718dbd3..deae17aa0ed7 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -822,6 +822,17 @@ static inline bool xas_valid(const struct xa_state *xas)
return !xas_invalid(xas);
}
+/**
+ * xas_is_node() - Does the xas point to a node?
+ * @xas: XArray operation state.
+ *
+ * Return: %true if the xas currently references a node.
+ */
+static inline bool xas_is_node(const struct xa_state *xas)
+{
+ return xas_valid(xas) && xas->xa_node;
+}
+
/* True if the pointer is something other than a node */
static inline bool xas_not_node(struct xa_node *node)
{
@@ -889,6 +900,8 @@ void xas_init_marks(const struct xa_state *);
bool xas_nomem(struct xa_state *, gfp_t);
void xas_pause(struct xa_state *);
+void xas_create_range(struct xa_state *);
+
/**
* xas_reload() - Refetch an entry from the xarray.
* @xas: XArray operation state.
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 8eba3de1baea..703370015d10 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -646,6 +646,124 @@ static noinline void check_move(struct xarray *xa)
check_move_small(xa, (1UL << i) - 1);
}
+static noinline void xa_store_many_order(struct xarray *xa,
+ unsigned long index, unsigned order)
+{
+ XA_STATE_ORDER(xas, xa, index, order);
+ unsigned int i = 0;
+
+ do {
+ xas_lock(&xas);
+ XA_BUG_ON(xa, xas_find_conflict(&xas));
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ for (i = 0; i < (1U << order); i++) {
+ XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(index + i)));
+ xas_next(&xas);
+ }
+unlock:
+ xas_unlock(&xas);
+ } while (xas_nomem(&xas, GFP_KERNEL));
+
+ XA_BUG_ON(xa, xas_error(&xas));
+}
+
+static noinline void check_create_range_1(struct xarray *xa,
+ unsigned long index, unsigned order)
+{
+ unsigned long i;
+
+ xa_store_many_order(xa, index, order);
+ for (i = index; i < index + (1UL << order); i++)
+ xa_erase_index(xa, i);
+ XA_BUG_ON(xa, !xa_empty(xa));
+}
+
+static noinline void check_create_range_2(struct xarray *xa, unsigned order)
+{
+ unsigned long i;
+ unsigned long nr = 1UL << order;
+
+ for (i = 0; i < nr * nr; i += nr)
+ xa_store_many_order(xa, i, order);
+ for (i = 0; i < nr * nr; i++)
+ xa_erase_index(xa, i);
+ XA_BUG_ON(xa, !xa_empty(xa));
+}
+
+static noinline void check_create_range_3(void)
+{
+ XA_STATE(xas, NULL, 0);
+ xas_set_err(&xas, -EEXIST);
+ xas_create_range(&xas);
+ XA_BUG_ON(NULL, xas_error(&xas) != -EEXIST);
+}
+
+static noinline void check_create_range_4(struct xarray *xa,
+ unsigned long index, unsigned order)
+{
+ XA_STATE_ORDER(xas, xa, index, order);
+ unsigned long base = xas.xa_index;
+ unsigned long i = 0;
+
+ xa_store_index(xa, index, GFP_KERNEL);
+ do {
+ xas_lock(&xas);
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ for (i = 0; i < (1UL << order); i++) {
+ void *old = xas_store(&xas, xa_mk_value(base + i));
+ if (xas.xa_index == index)
+ XA_BUG_ON(xa, old != xa_mk_value(base + i));
+ else
+ XA_BUG_ON(xa, old != NULL);
+ xas_next(&xas);
+ }
+unlock:
+ xas_unlock(&xas);
+ } while (xas_nomem(&xas, GFP_KERNEL));
+
+ XA_BUG_ON(xa, xas_error(&xas));
+
+ for (i = base; i < base + (1UL << order); i++)
+ xa_erase_index(xa, i);
+ XA_BUG_ON(xa, !xa_empty(xa));
+}
+
+static noinline void check_create_range(struct xarray *xa)
+{
+ unsigned int order;
+ unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 12 : 1;
+
+ for (order = 0; order < max_order; order++) {
+ check_create_range_1(xa, 0, order);
+ check_create_range_1(xa, 1U << order, order);
+ check_create_range_1(xa, 2U << order, order);
+ check_create_range_1(xa, 3U << order, order);
+ check_create_range_1(xa, 1U << 24, order);
+ if (order < 10)
+ check_create_range_2(xa, order);
+
+ check_create_range_4(xa, 0, order);
+ check_create_range_4(xa, 1U << order, order);
+ check_create_range_4(xa, 2U << order, order);
+ check_create_range_4(xa, 3U << order, order);
+ check_create_range_4(xa, 1U << 24, order);
+
+ check_create_range_4(xa, 1, order);
+ check_create_range_4(xa, (1U << order) + 1, order);
+ check_create_range_4(xa, (2U << order) + 1, order);
+ check_create_range_4(xa, (2U << order) - 1, order);
+ check_create_range_4(xa, (3U << order) + 1, order);
+ check_create_range_4(xa, (3U << order) - 1, order);
+ check_create_range_4(xa, (1U << 24) + 1, order);
+ }
+
+ check_create_range_3();
+}
+
static noinline void check_destroy(struct xarray *xa)
{
unsigned long index;
@@ -694,6 +812,7 @@ static int xarray_checks(void)
check_find(&array);
check_destroy(&array);
check_move(&array);
+ check_create_range(&array);
check_store_iter(&array);
printk("XArray: %u of %u tests passed\n", tests_passed, tests_run);
diff --git a/lib/xarray.c b/lib/xarray.c
index 41f8ebc651f5..ff37516fe832 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -637,6 +637,56 @@ static void *xas_create(struct xa_state *xas)
return entry;
}
+/**
+ * xas_create_range() - Ensure that stores to this range will succeed
+ * @xas: XArray operation state.
+ *
+ * Creates all of the slots in the range covered by @xas. Sets @xas to
+ * create single-index entries and positions it at the beginning of the
+ * range. This is for the benefit of users which have not yet been
+ * converted to use multi-index entries.
+ */
+void xas_create_range(struct xa_state *xas)
+{
+ unsigned long index = xas->xa_index;
+ unsigned char shift = xas->xa_shift;
+ unsigned char sibs = xas->xa_sibs;
+
+ xas->xa_index |= ((sibs + 1) << shift) - 1;
+ if (xas_is_node(xas) && xas->xa_node->shift == xas->xa_shift)
+ xas->xa_offset |= sibs;
+ xas->xa_shift = 0;
+ xas->xa_sibs = 0;
+
+ for (;;) {
+ xas_create(xas);
+ if (xas_error(xas))
+ goto restore;
+ if (xas->xa_index <= (index | XA_CHUNK_MASK))
+ goto success;
+ xas->xa_index -= XA_CHUNK_SIZE;
+
+ for (;;) {
+ struct xa_node *node = xas->xa_node;
+ xas->xa_node = xa_parent_locked(xas->xa, node);
+ xas->xa_offset = node->offset - 1;
+ if (node->offset != 0)
+ break;
+ }
+ }
+
+restore:
+ xas->xa_shift = shift;
+ xas->xa_sibs = sibs;
+ xas->xa_index = index;
+ return;
+success:
+ xas->xa_index = index;
+ if (xas->xa_node)
+ xas_set_offset(xas);
+}
+EXPORT_SYMBOL_GPL(xas_create_range);
+
static void update_node(struct xa_state *xas, struct xa_node *node,
int count, int values)
{