From 02e23d1a1a8c3baf73d82da5abbab3a4eeb1cbf4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 4 Apr 2019 11:27:08 +0200
Subject: [PATCH] Add fdopen_unlocked() wrapper

---
 coccinelle/fopen-unlocked.cocci | 12 ++++++++++++
 src/basic/fileio.c              | 20 +++++++++++++++-----
 src/basic/fileio.h              |  1 +
 src/basic/tmpfile-util.c        | 11 +++++------
 src/portable/portable.c         | 10 ++++------
 5 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/coccinelle/fopen-unlocked.cocci b/coccinelle/fopen-unlocked.cocci
index e6f2bc5681..bbd70a6338 100644
--- a/coccinelle/fopen-unlocked.cocci
+++ b/coccinelle/fopen-unlocked.cocci
@@ -49,3 +49,15 @@ expression f, g, path, p;
   if (r < 0)
     return ...;
 - (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+@@
+expression f, fd, options;
+@@
+- f = fdopen(fd, options);
++ r = fdopen_unlocked(fd, options, &f);
++ if (r < 0) {
+- if (!f) {
+        ...
+-       return -errno;
++       return r;
+  }
+- (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 2318f407b8..af22ec9110 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -42,6 +42,19 @@ int fopen_unlocked(const char *path, const char *options, FILE **ret) {
         return 0;
 }
 
+int fdopen_unlocked(int fd, const char *options, FILE **ret) {
+        assert(ret);
+
+        FILE *f = fdopen(fd, options);
+        if (!f)
+                return -errno;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        *ret = f;
+        return 0;
+}
+
 int write_string_stream_ts(
                 FILE *f,
                 const char *line,
@@ -167,14 +180,11 @@ int write_string_file_ts(
                         goto fail;
                 }
 
-                f = fdopen(fd, "w");
-                if (!f) {
-                        r = -errno;
+                r = fdopen_unlocked(fd, "w", &f);
+                if (r < 0) {
                         safe_close(fd);
                         goto fail;
                 }
-
-                (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
         }
 
         if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
diff --git a/src/basic/fileio.h b/src/basic/fileio.h
index bee3353439..7903b57c80 100644
--- a/src/basic/fileio.h
+++ b/src/basic/fileio.h
@@ -34,6 +34,7 @@ typedef enum {
 } ReadFullFileFlags;
 
 int fopen_unlocked(const char *path, const char *options, FILE **ret);
+int fdopen_unlocked(int fd, const char *options, FILE **ret);
 
 int write_string_stream_ts(FILE *f, const char *line, WriteStringFileFlags flags, struct timespec *ts);
 static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
diff --git a/src/basic/tmpfile-util.c b/src/basic/tmpfile-util.c
index 260443a1d6..3ed91520b9 100644
--- a/src/basic/tmpfile-util.c
+++ b/src/basic/tmpfile-util.c
@@ -6,6 +6,7 @@
 
 #include "alloc-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "fs-util.h"
 #include "hexdecoct.h"
 #include "macro.h"
@@ -42,16 +43,14 @@ int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
         /* This assumes that returned FILE object is short-lived and used within the same single-threaded
          * context and never shared externally, hence locking is not necessary. */
 
-        f = fdopen(fd, "w");
-        if (!f) {
-                unlink_noerrno(t);
+        r = fdopen_unlocked(fd, "w", &f);
+        if (r < 0) {
+                unlink(t);
                 free(t);
                 safe_close(fd);
-                return -errno;
+                return r;
         }
 
-        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
-
         *_f = f;
         *_temp_path = t;
 
diff --git a/src/portable/portable.c b/src/portable/portable.c
index 9b6cc21d2c..4aa879801f 100644
--- a/src/portable/portable.c
+++ b/src/portable/portable.c
@@ -1091,12 +1091,10 @@ static int test_chroot_dropin(
                 return log_debug_errno(errno, "Failed to open %s/%s: %m", where, p);
         }
 
-        f = fdopen(fd, "r");
-        if (!f)
-                return log_debug_errno(errno, "Failed to convert file handle: %m");
-        fd = -1;
-
-        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        r = fdopen_unlocked(fd, "r", &f);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to convert file handle: %m");
+        TAKE_FD(fd);
 
         r = read_line(f, LONG_LINE_MAX, &line);
         if (r < 0)