From bb1890afd7d1eb33e95f36d1d9936dbd574260b6 Mon Sep 17 00:00:00 2001
From: Peri <peri@srdi.org>
Date: Thu, 11 May 2023 02:38:46 +0100
Subject: Fix issue #746. (#782)

Added a secondary check in fuse_lib_unlink() after hide_node()
to check again under a lock if the (now hidden) file is still open.
If not then delete it.

This should synchronise fuse_lib_unlink() with fuse_lib_release(),
when nullpath_ok is set.
---
 test/release_unlink_race.c | 111 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 test/release_unlink_race.c

(limited to 'test/release_unlink_race.c')

diff --git a/test/release_unlink_race.c b/test/release_unlink_race.c
new file mode 100644
index 0000000..2edb200
--- /dev/null
+++ b/test/release_unlink_race.c
@@ -0,0 +1,111 @@
+/*
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file COPYING.
+*/
+
+#define FUSE_USE_VERSION 31
+
+#define _GNU_SOURCE
+
+#include <fuse.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+static void *xmp_init(struct fuse_conn_info *conn,
+		      struct fuse_config *cfg)
+{
+	(void) conn;
+
+	cfg->use_ino = 1;
+	cfg->nullpath_ok = 1;
+	cfg->entry_timeout = 0;
+	cfg->attr_timeout = 0;
+	cfg->negative_timeout = 0;
+
+	return NULL;
+}
+
+static int xmp_getattr(const char *path, struct stat *stbuf,
+			struct fuse_file_info *fi)
+{
+	int res;
+
+	(void) path;
+
+	if(fi)
+		res = fstat(fi->fh, stbuf);
+	else
+		res = lstat(path, stbuf);
+	if (res == -1)
+		return -errno;
+
+	return 0;
+}
+
+static int xmp_unlink(const char *path)
+{
+	int res;
+
+	res = unlink(path);
+	if (res == -1)
+		return -errno;
+
+	return 0;
+}
+
+static int xmp_rename(const char *from, const char *to, unsigned int flags)
+{
+	int res;
+
+	if (flags)
+		return -EINVAL;
+
+        if(!getenv("RELEASEUNLINKRACE_DELAY_DISABLE")) usleep(100000);
+
+	res = rename(from, to);
+	if (res == -1)
+		return -errno;
+
+	return 0;
+}
+
+static int xmp_create(const char *path, mode_t mode, struct fuse_file_info *fi)
+{
+	int fd;
+
+	fd = open(path, fi->flags, mode);
+	if (fd == -1)
+		return -errno;
+
+	fi->fh = fd;
+	return 0;
+}
+
+static int xmp_release(const char *path, struct fuse_file_info *fi)
+{
+	(void) path;
+
+        if(!getenv("RELEASEUNLINKRACE_DELAY_DISABLE")) usleep(100000);
+
+	close(fi->fh);
+
+	return 0;
+}
+
+static const struct fuse_operations xmp_oper = {
+	.init           = xmp_init,
+	.getattr	= xmp_getattr,
+	.unlink		= xmp_unlink,
+	.rename		= xmp_rename,
+	.create		= xmp_create,
+	.release	= xmp_release,
+};
+
+int main(int argc, char *argv[])
+{
+	umask(0);
+	return fuse_main(argc, argv, &xmp_oper, NULL);
+}
-- 
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