generator: add helper function for writing unit files

It doesn't save too much, but it's a common pattern so I think it's worth
to factor this out.

1 files changed, 14 insertions, 40 deletions

diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index 22c4ae9861..95bc5e38d5 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -102,7 +102,7 @@ static int add_swap(
                 struct mntent *me,
                 MountpointFlags flags) {
 
-        _cleanup_free_ char *name = NULL, *unit = NULL;
+        _cleanup_free_ char *name = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
@@ -123,19 +123,9 @@ static int add_swap(
         if (r < 0)
                 return log_error_errno(r, "Failed to generate unit name: %m");
 
-        unit = strjoin(arg_dest, "/", name);
-        if (!unit)
-                return log_oom();
-
-        f = fopen(unit, "wxe");
-        if (!f)
-                return log_error_errno(errno,
-                                       errno == EEXIST ?
-                                       "Failed to create swap unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
-                                       "Failed to create unit file %s: %m",
-                                       unit);
-
-        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        r = generator_open_unit_file(arg_dest, "/etc/fstab", name, &f);
+        if (r < 0)
+                return r;
 
         fputs("# Automatically generated by systemd-fstab-generator\n\n"
               "[Unit]\n"
@@ -153,7 +143,7 @@ static int add_swap(
 
         r = fflush_and_check(f);
         if (r < 0)
-                return log_error_errno(r, "Failed to write unit file %s: %m", unit);
+                return log_error_errno(r, "Failed to write unit file %s: %m", name);
 
         /* use what as where, to have a nicer error message */
         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
@@ -323,10 +313,9 @@ static int add_mount(
 
         _cleanup_free_ char
                 *name = NULL,
-                *automount_name = NULL, *automount_unit = NULL,
+                *automount_name = NULL,
                 *filtered = NULL,
                 *where_escaped = NULL;
-        const char *unit;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
@@ -363,20 +352,11 @@ static int add_mount(
         if (r < 0)
                 return log_error_errno(r, "Failed to generate unit name: %m");
 
-        unit = strjoina(dest, "/", name);
-
-        f = fopen(unit, "wxe");
-        if (!f)
-                return log_error_errno(errno,
-                                       errno == EEXIST ?
-                                       "Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
-                                       "Failed to create unit file %s: %m",
-                                       unit);
-
-        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        r = generator_open_unit_file(dest, "/etc/fstab", name, &f);
+        if (r < 0)
+                return r;
 
         fprintf(f,
-                "# Automatically generated by systemd-fstab-generator\n\n"
                 "[Unit]\n"
                 "SourcePath=%s\n"
                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
@@ -461,7 +441,7 @@ static int add_mount(
 
         r = fflush_and_check(f);
         if (r < 0)
-                return log_error_errno(r, "Failed to write unit file %s: %m", unit);
+                return log_error_errno(r, "Failed to write unit file %s: %m", name);
 
         if (flags & MAKEFS) {
                 r = generator_hook_up_mkfs(dest, what, where, fstype);
@@ -487,19 +467,13 @@ static int add_mount(
                 if (r < 0)
                         return log_error_errno(r, "Failed to generate unit name: %m");
 
-                automount_unit = strjoin(dest, "/", automount_name);
-                if (!automount_unit)
-                        return log_oom();
-
                 fclose(f);
-                f = fopen(automount_unit, "wxe");
-                if (!f)
-                        return log_error_errno(errno, "Failed to create unit file %s: %m", automount_unit);
 
-                (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+                r = generator_open_unit_file(dest, "/etc/fstab", automount_name, &f);
+                if (r < 0)
+                        return r;
 
                 fprintf(f,
-                        "# Automatically generated by systemd-fstab-generator\n\n"
                         "[Unit]\n"
                         "SourcePath=%s\n"
                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
@@ -534,7 +508,7 @@ static int add_mount(
 
                 r = fflush_and_check(f);
                 if (r < 0)
-                        return log_error_errno(r, "Failed to write unit file %s: %m", automount_unit);
+                        return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 
                 r = generator_add_symlink(dest, post,
                                           (flags & NOFAIL) ? "wants" : "requires", automount_name);