f2fs: preserve extent info for extent cache
This patch tries to preserve last extent info in extent tree cache into on-disk
inode, so this can help us to reuse the last extent info next time for
performance.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e3be4be..8a940e5 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -719,6 +719,55 @@
atomic_dec(&et->refcount);
}
+void f2fs_preserve_extent_tree(struct inode *inode)
+{
+ struct extent_tree *et;
+ struct extent_info *ext = &F2FS_I(inode)->ext;
+ bool sync = false;
+
+ if (!test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+ return;
+
+ et = __find_extent_tree(F2FS_I_SB(inode), inode->i_ino);
+ if (!et) {
+ if (ext->len) {
+ ext->len = 0;
+ update_inode_page(inode);
+ }
+ return;
+ }
+
+ read_lock(&et->lock);
+ if (et->count) {
+ struct extent_node *en;
+
+ if (et->cached_en) {
+ en = et->cached_en;
+ } else {
+ struct rb_node *node = rb_first(&et->root);
+
+ if (!node)
+ node = rb_last(&et->root);
+ en = rb_entry(node, struct extent_node, rb_node);
+ }
+
+ if (__is_extent_same(ext, &en->ei))
+ goto out;
+
+ *ext = en->ei;
+ sync = true;
+ } else if (ext->len) {
+ ext->len = 0;
+ sync = true;
+ }
+out:
+ read_unlock(&et->lock);
+ atomic_dec(&et->refcount);
+
+ if (sync)
+ update_inode_page(inode);
+}
+
void f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
{
struct extent_tree *treevec[EXT_TREE_VEC_SIZE];