swap: create .wants symlink to 'auto' swap devices

As we load unit files lazily, we need to make sure something pulls in swap
units that should be started automatically, otherwise the default dependencies
will never be applied.

This partially reinstates code removed in
commit 64347fc2b983f33e7efb0fd2bb44e133fb9f30f4.

Also don't order swap devices after swap.target when they are 'nofail'.

1 files changed, 16 insertions, 2 deletions

diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index 6ebe8aa673..b73dfa4899 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -66,6 +66,7 @@ static int mount_find_pri(struct mntent *me, int *ret) {
 static int add_swap(const char *what, struct mntent *me) {
         _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL;
         _cleanup_fclose_ FILE *f = NULL;
+        bool noauto;
         int r, pri = -1;
 
         assert(what);
@@ -77,6 +78,8 @@ static int add_swap(const char *what, struct mntent *me) {
                 return pri;
         }
 
+        noauto = !!hasmntopt(me, "noauto");
+
         name = unit_name_from_path(what, ".swap");
         if (!name)
                 return log_oom();
@@ -97,8 +100,7 @@ static int add_swap(const char *what, struct mntent *me) {
         fprintf(f,
                 "# Automatically generated by systemd-fstab-generator\n\n"
                 "[Unit]\n"
-                "SourcePath=/etc/fstab\n"
-                "\n"
+                "SourcePath=/etc/fstab\n\n"
                 "[Swap]\n"
                 "What=%s\n",
                 what);
@@ -114,6 +116,18 @@ static int add_swap(const char *what, struct mntent *me) {
                 return -errno;
         }
 
+        if (!noauto) {
+                lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
+                if (!lnk)
+                        return log_oom();
+
+                mkdir_parents_label(lnk, 0755);
+                if (symlink(unit, lnk) < 0) {
+                        log_error("Failed to create symlink %s: %m", lnk);
+                        return -errno;
+                }
+        }
+
         return 0;
 }