From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Avoids walking the radix tree multiple times looking for tags.
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
fs/dax.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 825bf153f499..9602db13aa65 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -657,27 +657,28 @@ EXPORT_SYMBOL_GPL(dax_layout_busy_page);
static int __dax_invalidate_entry(struct address_space *mapping,
pgoff_t index, bool trunc)
{
+ XA_STATE(xas, &mapping->i_pages, index);
int ret = 0;
void *entry;
- struct radix_tree_root *pages = &mapping->i_pages;
- xa_lock_irq(pages);
- entry = get_unlocked_mapping_entry(mapping, index, NULL);
+ xas_lock_irq(&xas);
+ entry = get_unlocked_entry(&xas);
if (!entry || WARN_ON_ONCE(!xa_is_value(entry)))
goto out;
if (!trunc &&
- (radix_tree_tag_get(pages, index, PAGECACHE_TAG_DIRTY) ||
- radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE)))
+ (xas_get_tag(&xas, PAGECACHE_TAG_DIRTY) ||
+ xas_get_tag(&xas, PAGECACHE_TAG_TOWRITE)))
goto out;
dax_disassociate_entry(entry, mapping, trunc);
- radix_tree_delete(pages, index);
+ xas_store(&xas, NULL);
mapping->nrexceptional--;
ret = 1;
out:
- put_unlocked_mapping_entry(mapping, index, entry);
- xa_unlock_irq(pages);
+ put_unlocked_entry(&xas, entry);
+ xas_unlock_irq(&xas);
return ret;
}
+
/*
* Delete DAX entry at @index from @mapping. Wait for it
* to be unlocked before deleting it.
--
2.16.2
