[PATCHv1, RFC 06/33] radix-tree: Handle multiorder entries being deleted by replace_clear_tags
From: Kirill A. Shutemov <hidden>
Date: 2016-07-26 00:35:08
Also in:
linux-ext4, linux-fsdevel, linux-mm, lkml
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
From: Matthew Wilcox <willy@infradead.org> radix_tree_replace_clear_tags() can be called with NULL as the replacement value; in this case we need to delete sibling entries which point to the slot. Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Kirill A. Shutemov <redacted> --- lib/radix-tree.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index e49f32f7c537..89092c4011b8 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c@@ -1799,17 +1799,23 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) } EXPORT_SYMBOL(radix_tree_delete); +/* + * If the caller passes NULL for @entry, it must take care to adjust + * node->count. See page_cache_tree_delete() for an example. + */ struct radix_tree_node *radix_tree_replace_clear_tags( struct radix_tree_root *root, unsigned long index, void *entry) { struct radix_tree_node *node; void **slot; + unsigned int offset; __radix_tree_lookup(root, index, &node, &slot); if (node) { - unsigned int tag, offset = get_slot_offset(node, slot); + unsigned int tag; + offset = get_slot_offset(node, slot); for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) node_tag_clear(root, node, tag, offset); } else {
@@ -1818,6 +1824,9 @@ struct radix_tree_node *radix_tree_replace_clear_tags( } radix_tree_replace_slot(slot, entry); + if (!entry && node) + delete_sibling_entries(node, node_to_entry(slot), offset); + return node; }
--
2.8.1