swap: restore support for nofail

systemd stops adding automatic dependencies on swap.target to swap
units. If a dependency is required, it has to be added by unit
configuration. fstab-generator did that already, except that now it is
modified to create a Requires or Wants type dependency, depending on
whether nofail is specified in /etc/fstab. This makes .swap units
obey the nofail/noauto options more or less the same as .mount units.

Documentation is extended to clarify that, and to make
systemd.mount(5) and system.swap(5) more similar. The gist is not
changed, because current behaviour actually matches existing
documentation.

https://bugs.freedesktop.org/show_bug.cgi?id=86488

1 files changed, 16 insertions, 11 deletions

diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index af45c25400..14e664236e 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -74,11 +74,14 @@ static int mount_find_pri(struct mntent *me, int *ret) {
         return 1;
 }
 
-static int add_swap(const char *what, struct mntent *me) {
+static int add_swap(
+                const char *what,
+                struct mntent *me,
+                bool noauto,
+                bool nofail) {
+
         _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
         _cleanup_fclose_ FILE *f = NULL;
-
-        bool noauto;
         int r, pri = -1;
 
         assert(what);
@@ -95,8 +98,6 @@ static int add_swap(const char *what, struct mntent *me) {
                 return r;
         }
 
-        noauto = !!hasmntopt(me, "noauto");
-
         name = unit_name_from_path(what, ".swap");
         if (!name)
                 return log_oom();
@@ -143,7 +144,8 @@ static int add_swap(const char *what, struct mntent *me) {
                 return r;
 
         if (!noauto) {
-                lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
+                lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET,
+                              nofail ? ".wants/" : ".requires/", name, NULL);
                 if (!lnk)
                         return log_oom();
 
@@ -357,6 +359,7 @@ static int parse_fstab(bool initrd) {
 
         while ((me = getmntent(f))) {
                 _cleanup_free_ char *where = NULL, *what = NULL;
+                bool noauto, nofail;
                 int k;
 
                 if (initrd && !mount_in_initrd(me))
@@ -378,16 +381,18 @@ static int parse_fstab(bool initrd) {
                 if (is_path(where))
                         path_kill_slashes(where);
 
-                log_debug("Found entry what=%s where=%s type=%s", what, where, me->mnt_type);
+                noauto = !!hasmntopt(me, "noauto");
+                nofail = !!hasmntopt(me, "nofail");
+                log_debug("Found entry what=%s where=%s type=%s nofail=%s noauto=%s",
+                          what, where, me->mnt_type,
+                          yes_no(noauto), yes_no(nofail));
 
                 if (streq(me->mnt_type, "swap"))
-                        k = add_swap(what, me);
+                        k = add_swap(what, me, noauto, nofail);
                 else {
-                        bool noauto, nofail, automount;
+                        bool automount;
                         const char *post;
 
-                        noauto = !!hasmntopt(me, "noauto");
-                        nofail = !!hasmntopt(me, "nofail");
                         automount =
                                   hasmntopt(me, "comment=systemd.automount") ||
                                   hasmntopt(me, "x-systemd.automount");