From 43d416003a0502513d6b50187c46e1e1b1acdb01 Mon Sep 17 00:00:00 2001
From: Zach Brown <zab@versity.com>
Date: Thu, 24 Oct 2019 15:54:35 -0700
Subject: [PATCH] scoutfs: add scoutfs_btree_force

Add a btree_update variant which will insert the item if a previous
wasn't found instead of returning -ENOENT.  This saves callers from
having to lookup befure updating to discover if they should call _create
or _update.

Signed-off-by: Zach Brown <zab@versity.com>
---
 kmod/src/btree.c | 34 ++++++++++++++++++++++++++++++++++
 kmod/src/btree.h |  6 ++++++
 2 files changed, 40 insertions(+)

diff --git a/kmod/src/btree.c b/kmod/src/btree.c
index c8919c52..936de009 100644
--- a/kmod/src/btree.c
+++ b/kmod/src/btree.c
@@ -1115,6 +1115,40 @@ int scoutfs_btree_update(struct super_block *sb,
 	return ret;
 }
 
+/*
+ * Create an item, overwriting any item that might exist.  It's _update
+ * which will insert instead of returning -ENOENT.
+ */
+int scoutfs_btree_force(struct super_block *sb,
+			struct scoutfs_balloc_allocator *alloc,
+			struct scoutfs_block_writer *wri,
+			struct scoutfs_btree_root *root,
+			void *key, unsigned key_len,
+			void *val, unsigned val_len)
+{
+	struct scoutfs_btree_block *bt;
+	struct scoutfs_block *bl;
+	int pos;
+	int cmp;
+	int ret;
+
+	if (invalid_item(key, key_len, val_len))
+		return -EINVAL;
+
+	ret = btree_walk(sb, alloc, wri, root, BTW_DIRTY | BTW_INSERT,
+			 key, key_len, val_len, &bl, NULL, NULL);
+	if (ret == 0) {
+		bt = bl->data;
+		pos = find_pos(bt, key, key_len, &cmp);
+		if (cmp == 0)
+			delete_item(bt, pos);
+		create_item(bt, pos, key, key_len, val, val_len);
+		scoutfs_block_put(sb, bl);
+	}
+
+	return ret;
+}
+
 /*
  * Delete an item from the tree.  -ENOENT is returned if the key isn't
  * found.
diff --git a/kmod/src/btree.h b/kmod/src/btree.h
index d56b2f3e..9278cec8 100644
--- a/kmod/src/btree.h
+++ b/kmod/src/btree.h
@@ -35,6 +35,12 @@ int scoutfs_btree_update(struct super_block *sb,
 			 struct scoutfs_btree_root *root,
 			 void *key, unsigned key_len,
 			 void *val, unsigned val_len);
+int scoutfs_btree_force(struct super_block *sb,
+			struct scoutfs_balloc_allocator *alloc,
+			struct scoutfs_block_writer *wri,
+			struct scoutfs_btree_root *root,
+			void *key, unsigned key_len,
+			void *val, unsigned val_len);
 int scoutfs_btree_delete(struct super_block *sb,
 			 struct scoutfs_balloc_allocator *alloc,
 			 struct scoutfs_block_writer *wri,