Add a "radix_tree_gang_set_if_tagged" operation, which takes a range of indexes,
and sets a given tag, if any of the specified tags were found to be set. Used by
the next patch to set an "fsync" bit on any dirty and writeback pages.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
---
include/linux/radix-tree.h | 1
lib/radix-tree.c | 107 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+)
Index: linux-2.6/include/linux/radix-tree.h
===================================================================
--- linux-2.6.orig/include/linux/radix-tree.h
+++ linux-2.6/include/linux/radix-tree.h
@@ -183,6 +183,7 @@ unsigned int
radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
unsigned long first_index, unsigned int max_items,
unsigned int tag);
+int radix_tree_gang_tag_set_if_tagged(struct radix_tree_root *root, unsigned long first_index, unsigned long last_index, unsigned long ifset, unsigned long thentag);
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
static inline void radix_tree_preload_end(void)
Index: linux-2.6/lib/radix-tree.c
===================================================================
--- linux-2.6.orig/lib/radix-tree.c
+++ linux-2.6/lib/radix-tree.c
@@ -629,6 +629,113 @@ int radix_tree_tag_get(struct radix_tree
EXPORT_SYMBOL(radix_tree_tag_get);
#endif
+int node_tag_set_if_tagged(struct radix_tree_node *node, unsigned int height, unsigned long first_index, unsigned long last_index, unsigned long ifset, unsigned long thentag)
+{
+ unsigned long first, last;
+ int offset_start, offset_end, i;
+ int ret = 0;
+ unsigned int shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ unsigned int size = RADIX_TREE_MAP_SIZE << shift;
+
+ first = first_index;
+ last = min(last_index, ((first + size) & ~(size-1)) - 1);
+
+ offset_start = (first_index >> shift) & RADIX_TREE_MAP_MASK;
+ offset_end = (last_index >> shift) & RADIX_TREE_MAP_MASK;
+ for (i = offset_start; i <= offset_end; i++) {
+
+ if (height > 1) {
+ struct radix_tree_node *slot;
+
+ slot = node->slots[i];
+ if (!slot)
+ goto notset;
+
+ if (node_tag_set_if_tagged(slot, height - 1,
+ first, last,
+ ifset, thentag)) {
+ if (ifset == 0x1)
+ BUG_ON(!tag_get(node, 0, i));
+ if (ifset == 0x2)
+ BUG_ON(!tag_get(node, 1, i));
+ if (ifset == 0x2)
+ BUG_ON(!tag_get(node, 0, i) &&
+ !tag_get(node, 1, i));
+ if (thentag & 0x4) {
+ if (!tag_get(node, 2, i))
+ tag_set(node, 2, i);
+ }
+ ret = 1;
+ }
+notset:
+ first = last+1;
+ last = min(last_index, first + size - 1);
+
+ } else {
+ if (ifset & 0x1) {
+ if (tag_get(node, 0, i))
+ goto isset;
+ }
+ if (ifset & 0x2) {
+ if (tag_get(node, 1, i))
+ goto isset;
+ }
+ continue;
+isset:
+ if (thentag & 0x4) {
+ if (!tag_get(node, 2, i))
+ tag_set(node, 2, i);
+ }
+ ret = 1;
+ }
+ }
+
+ return ret;
+}
+
+int radix_tree_gang_tag_set_if_tagged(struct radix_tree_root *root, unsigned long first_index, unsigned long last_index, unsigned long ifset, unsigned long thentag)
+{
+ unsigned int height;
+ struct radix_tree_node *slot;
+
+ BUG_ON(ifset & ~0x3);
+ BUG_ON(thentag & ~0x4);
+
+ height = root->height;
+ if (height == 0) {
+ /* set the root's tag bit */
+ if (first_index != 0)
+ return 0;
+
+ if (ifset & 0x1)
+ if (root_tag_get(root, 0))
+ goto isset;
+ if (ifset & 0x2)
+ if (root_tag_get(root, 1))
+ goto isset;
+ return 0;
+isset:
+ if (thentag & 0x4) {
+ if (!root_tag_get(root, 2))
+ root_tag_set(root, 2);
+ }
+ return 1;
+ }
+
+ slot = radix_tree_indirect_to_ptr(root->rnode);
+ if (node_tag_set_if_tagged(slot, height, first_index, last_index, ifset, thentag)) {
+ /* set the root's tag bit */
+ if (thentag & 0x4) {
+ if (!root_tag_get(root, 2))
+ root_tag_set(root, 2);
+ }
+
+ return 1;
+ }
+
+ return 0;
+}
+
/**
* radix_tree_next_hole - find the next hole (not-present entry)
* @root: tree root
--
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