From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Mon, 10 Jul 2017 03:59:30 +0000 (-0400)
Subject: sysv-generator: use generator_add_symlink()
X-Git-Tag: v235~329^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7f0cc63771aeb792bb5fff1e22c471132ffa054b;p=thirdparty%2Fsystemd.git

sysv-generator: use generator_add_symlink()

generator_add_symlink() is extended to ignore EEXIST. This should be fine
for all existing callers.

There's a small difference in behaviour when adding symlinks in sysv-generator:
the message is more generic and does not include ", ignored". But creation of
symlinks shouldn't ever fail except if things are very wrong, so in practice
this shouldn't matter.

Test needed updating: os.path.exists(os.readlink(link)) only works if the link
is absolute (or if we are in the right directory). Let's just use
os.path.exists(link), which properly tests that the symlink target exists.
---

diff --git a/src/shared/generator.c b/src/shared/generator.c
index 0a829dc9af3..2f459bf7786 100644
--- a/src/shared/generator.c
+++ b/src/shared/generator.c
@@ -47,7 +47,8 @@ int generator_add_symlink(const char *root, const char *dst, const char *dep_typ
 
         mkdir_parents_label(to, 0755);
         if (symlink(from, to) < 0)
-                return log_error_errno(errno, "Failed to create symlink \"%s\": %m", to);
+                if (errno != EEXIST)
+                        return log_error_errno(errno, "Failed to create symlink \"%s\": %m", to);
 
         return 0;
 }
diff --git a/src/sysv-generator/sysv-generator.c b/src/sysv-generator/sysv-generator.c
index 98280784439..3f3237d9b38 100644
--- a/src/sysv-generator/sysv-generator.c
+++ b/src/sysv-generator/sysv-generator.c
@@ -28,6 +28,7 @@
 #include "exit-status.h"
 #include "fd-util.h"
 #include "fileio.h"
+#include "generator.h"
 #include "hashmap.h"
 #include "hexdecoct.h"
 #include "install.h"
@@ -101,29 +102,6 @@ static void free_sysvstub_hashmapp(Hashmap **h) {
         hashmap_free(*h);
 }
 
-static int add_symlink(const char *service, const char *where) {
-        const char *from, *to;
-        int r;
-
-        assert(service);
-        assert(where);
-
-        from = strjoina(arg_dest, "/", service);
-        to = strjoina(arg_dest, "/", where, ".wants/", service);
-
-        mkdir_parents_label(to, 0755);
-
-        r = symlink(from, to);
-        if (r < 0) {
-                if (errno == EEXIST)
-                        return 0;
-
-                return -errno;
-        }
-
-        return 1;
-}
-
 static int add_alias(const char *service, const char *alias) {
         const char *link;
         int r;
@@ -219,11 +197,8 @@ static int generate_unit_file(SysvStub *s) {
         if (r < 0)
                 return log_error_errno(r, "Failed to write unit %s: %m", unit);
 
-        STRV_FOREACH(p, s->wanted_by) {
-                r = add_symlink(s->name, *p);
-                if (r < 0)
-                        log_warning_errno(r, "Failed to create 'Wants' symlink to %s, ignoring: %m", *p);
-        }
+        STRV_FOREACH(p, s->wanted_by)
+                (void) generator_add_symlink(arg_dest, *p, "wants", s->name);
 
         return 1;
 }
diff --git a/test/sysv-generator-test.py b/test/sysv-generator-test.py
index d116fffe38f..99e323db3b2 100755
--- a/test/sysv-generator-test.py
+++ b/test/sysv-generator-test.py
@@ -153,7 +153,8 @@ class SysvGeneratorTest(unittest.TestCase):
             link = os.path.join(self.out_dir, '%s.target.wants' % target, unit)
             if target in targets:
                 unit_file = os.readlink(link)
-                self.assertTrue(os.path.exists(unit_file))
+                # os.path.exists() will fail on a dangling symlink
+                self.assertTrue(os.path.exists(link))
                 self.assertEqual(os.path.basename(unit_file), unit)
             else:
                 self.assertFalse(os.path.exists(link),