From 6019598fdb9d223beec7da5848cf950ca90e85e7 Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher
Date: Sun, 24 May 2020 23:46:41 +0200
Subject: contrib: collect getdents stuff in getdents-debug folder

---
 contrib/getdents-debug/getdents/.gitignore   |  1 +
 contrib/getdents-debug/getdents/getdents.go  | 75 ++++++++++++++++++++++++++++
 contrib/getdents-debug/getdents_c/.gitignore |  1 +
 contrib/getdents-debug/getdents_c/Makefile   |  2 +
 contrib/getdents-debug/getdents_c/getdents.c | 39 +++++++++++++++
 5 files changed, 118 insertions(+)
 create mode 100644 contrib/getdents-debug/getdents/.gitignore
 create mode 100644 contrib/getdents-debug/getdents/getdents.go
 create mode 100644 contrib/getdents-debug/getdents_c/.gitignore
 create mode 100644 contrib/getdents-debug/getdents_c/Makefile
 create mode 100644 contrib/getdents-debug/getdents_c/getdents.c

(limited to 'contrib/getdents-debug')

diff --git a/contrib/getdents-debug/getdents/.gitignore b/contrib/getdents-debug/getdents/.gitignore
new file mode 100644
index 0000000..6dae481
--- /dev/null
+++ b/contrib/getdents-debug/getdents/.gitignore
@@ -0,0 +1 @@
+/getdents
diff --git a/contrib/getdents-debug/getdents/getdents.go b/contrib/getdents-debug/getdents/getdents.go
new file mode 100644
index 0000000..a70692a
--- /dev/null
+++ b/contrib/getdents-debug/getdents/getdents.go
@@ -0,0 +1,75 @@
+/*
+Small tool to try to debug unix.Getdents problems on CIFS mounts
+( https://github.com/rfjakob/gocryptfs/issues/483 )
+
+Example output:
+
+$ while sleep 1 ; do ./getdents /mnt/synology/public/tmp/g1 ; done
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=3192, err=<nil>
+unix.Getdents fd3: n=0, err=<nil>
+total 24072 bytes
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=-1, err=no such file or directory
+total 16704 bytes
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=4176, err=<nil>
+unix.Getdents fd3: n=3192, err=<nil>
+unix.Getdents fd3: n=0, err=<nil>
+total 24072 bytes
+*/
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	myName = "getdents"
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s PATH\n", myName)
+		fmt.Fprintf(os.Stderr, "Run getdents(2) on PATH\n")
+		os.Exit(1)
+	}
+	flag.Parse()
+	if flag.NArg() != 1 {
+		flag.Usage()
+	}
+	path := flag.Arg(0)
+
+	fd, err := unix.Open(path, unix.O_RDONLY, 0)
+	if err != nil {
+		log.Fatalf("unix.Open returned err=%v", err)
+	}
+
+	tmp := make([]byte, 10000)
+	sum := 0
+	for {
+		n, err := unix.Getdents(fd, tmp)
+		fmt.Printf("unix.Getdents fd%d: n=%d, err=%v\n", fd, n, err)
+		if n <= 0 {
+			fmt.Printf("total %d bytes\n", sum)
+			break
+		}
+		sum += n
+	}
+}
diff --git a/contrib/getdents-debug/getdents_c/.gitignore b/contrib/getdents-debug/getdents_c/.gitignore
new file mode 100644
index 0000000..2f94993
--- /dev/null
+++ b/contrib/getdents-debug/getdents_c/.gitignore
@@ -0,0 +1 @@
+/getdents_c
diff --git a/contrib/getdents-debug/getdents_c/Makefile b/contrib/getdents-debug/getdents_c/Makefile
new file mode 100644
index 0000000..95e47dc
--- /dev/null
+++ b/contrib/getdents-debug/getdents_c/Makefile
@@ -0,0 +1,2 @@
+getdents_c: *.c Makefile
+	gcc getdents.c -o getdents_c
diff --git a/contrib/getdents-debug/getdents_c/getdents.c b/contrib/getdents-debug/getdents_c/getdents.c
new file mode 100644
index 0000000..98c2346
--- /dev/null
+++ b/contrib/getdents-debug/getdents_c/getdents.c
@@ -0,0 +1,39 @@
+// See ../getdents/getdents.go for some info on why
+// this exists.
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <errno.h>
+
+int main(int argc, char *argv[])
+{
+    if(argc < 2) {
+        printf("Usage: %s PATH\n", argv[0]);
+        printf("Run getdents(2) on PATH\n");
+        exit(1);
+    }
+
+    const char *path = argv[1];
+    int fd = open(path, O_RDONLY);
+    if (fd == -1) {
+        perror("open");
+        exit(1);
+    }
+
+    char tmp[10000];
+    int sum = 0;
+    for ( ; ; ) {
+        int n = syscall(SYS_getdents64, fd, tmp, sizeof(tmp));
+        printf("getdents64 fd%d: n=%d, errno=%d\n", fd, n, errno);
+        if (n <= 0) {
+            printf("total %d bytes\n", sum);
+            break;
+        }
+        sum += n;
+    }
+}
-- 
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