From 1fc2d9c88af77c3af81b6bd461e6b019b97d2dbb Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Sat, 20 Jul 2024 23:17:36 +0200
Subject: *: moving files

---
 src/cmd/tmpfs.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 1 deletion(-)

(limited to 'src/cmd/tmpfs.c')

diff --git a/src/cmd/tmpfs.c b/src/cmd/tmpfs.c
index 6d58790..a031a44 100644
--- a/src/cmd/tmpfs.c
+++ b/src/cmd/tmpfs.c
@@ -1,3 +1,4 @@
+#include <assert.h>
 #include <camellia/flags.h>
 #include <camellia/fs/dir.h>
 #include <camellia/fs/misc.h>
@@ -38,8 +39,10 @@ static struct node *tmpfs_open(const char *path, struct ufs_request *req);
 static struct node *node_getchild(struct node *parent, const char *name, size_t len);
 /** Corresponds to close(); drops a reference. */
 static void node_close(struct node *node);
+static long node_move(struct node *from, struct node *to);
 /** Removes a file. It's kept in memory until all the open handles are closed. */
 static long node_remove(struct node *node);
+static void node_sanity(struct node *node, struct node **from);
 
 
 static struct node *node_getchild(struct node *parent, const char *name, size_t len) {
@@ -100,27 +103,84 @@ static struct node *tmpfs_open(const char *path, struct ufs_request *req) {
 
 static void node_close(struct node *node) {
 	node->open--;
-	if (!node->ref && node != &node_root && node->open == 0) {
+	if (node->ref == NULL && node != &node_root && node->open == 0) {
+		if (node->name) {
+			free(node->name);
+		}
 		free(node->buf);
 		free(node);
 	}
 }
 
+static long node_move(struct node *from, struct node *to) {
+	if (from == &node_root || to == &node_root) {
+		return -1;
+	}
+
+	assert(from && to);
+	/* 1. unlink from */
+	if (from->ref) {
+		assert(*from->ref == from);
+		if (from->sibling) {
+			from->sibling->ref = from->ref;
+			*from->sibling->ref = from->sibling;
+		} else {
+			*from->ref = NULL;
+		}
+		from->sibling = NULL;
+		from->ref = NULL;
+	} else {
+		assert(from->sibling == NULL);
+	}
+
+	/* 2. link *from in place of *to
+	 *    note that there's still a reference to *to in the handle */
+	if (to->ref) {
+		assert(*to->ref == to);
+		from->sibling = to->sibling;
+		if (from->sibling) {
+			from->sibling->ref = &from->sibling;
+		}
+		from->ref = to->ref;
+		*from->ref = from;
+
+		to->ref = NULL;
+		to->sibling = NULL;
+	}
+	from->name = to->name;
+	from->namelen = to->namelen;
+	to->name = NULL;
+	to->namelen = 0;
+	return 0;
+}
+
 static long node_remove(struct node *node) {
 	if (node == &node_root) return -1;
 	if (!node->ref) return -1;
 	if (node->child) return -ENOTEMPTY;
 	*node->ref = node->sibling;
 	node->ref = NULL;
+	node->sibling = NULL;
 	node_close(node);
 	return 0;
 }
 
+static void node_sanity(struct node *node, struct node **from) {
+	if (node == NULL) return;
+	if (node != &node_root && node->ref != from) {
+		assert(false);
+	}
+	node_sanity(node->sibling, &node->sibling);
+	node_sanity(node->child, &node->child);
+}
+
 int main(void) {
 	const size_t buflen = 4096;
 	char *buf = malloc(buflen);
 	if (!buf) return -1;
 
+	node_sanity(&node_root, NULL);
+
 	for (;;) {
 		struct ufs_request req;
 		hid_t reqh = ufs_wait(buf, buflen, &req);
@@ -189,10 +249,19 @@ int main(void) {
 				_sys_fs_respond(reqh, NULL, -1, 0);
 				break;
 
+			case VFSOP_DUPLEX:
+				if (req.flags == DUPLEX_REMOVE) {
+					_sys_fs_respond(reqh, NULL, node_move(req.id, req.id2), 0);
+				} else {
+					_sys_fs_respond(reqh, NULL, -ENOSYS, 0);
+				}
+				break;
+
 			default:
 				_sys_fs_respond(reqh, NULL, -1, 0);
 				break;
 		}
+		node_sanity(&node_root, NULL);
 	}
 	return 1;
 }
-- 
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