mount: let pid1 alone handle the default dependencies for mount units

fbuihuu · fbuihuu · commit 83cdc8709498 · 2020-04-09T15:17:09.000+02:00
fstab-generator was also handling the default ordering dependencies for mount
units setup in initrd. To do that it was turning the defaults dependencies off
completely and ordered the mount unit against either local-fs.target or
initrd-fs.target or initrd-root-fs.target itself.

But it had the bad side effect to also remove all other default dependencies as
well. Thus if an initrd mount was using _netdev, the network dependencies were
missing.

In general fstab-generator shouldn't use DefaultDependecies=no because it can
handle only a small set of the default dependencies the rest are dealt by pid1.

So this patch makes pid1 handle all default dependencies.
diff --git a/src/core/mount.c b/src/core/mount.c
@@ -428,7 +428,7 @@ static bool mount_is_extrinsic(Mount *m) {
 }
 
 static int mount_add_default_dependencies(Mount *m) {
-        const char *after, *before;
+        const char *after, *before, *e;
         UnitDependencyMask mask;
         MountParameters *p;
         bool nofail;
@@ -452,7 +452,16 @@ static int mount_add_default_dependencies(Mount *m) {
         mask = m->from_fragment ? UNIT_DEPENDENCY_FILE : UNIT_DEPENDENCY_MOUNTINFO_DEFAULT;
         nofail = m->from_fragment ? fstab_test_yes_no_option(m->parameters_fragment.options, "nofail\0" "fail\0") : false;
 
-        if (mount_is_network(p)) {
+        e = path_startswith(m->where, "/sysroot");
+        if (e && in_initrd()) {
+                /* All mounts under /sysroot need to happen later, at initrd-fs.target time. IOW,
+                 * it's not technically part of the basic initrd filesystem itself, and so
+                 * shouldn't inherit the default Before=local-fs.target dependency. */
+
+                after = NULL;
+                before = isempty(e) ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_INITRD_FS_TARGET;
+
+        } else if (mount_is_network(p)) {
                 /* We order ourselves after network.target. This is
                  * primarily useful at shutdown: services that take
                  * down the network should order themselves before
@@ -487,9 +496,11 @@ static int mount_add_default_dependencies(Mount *m) {
                         return r;
         }
 
-        r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, true, mask);
-        if (r < 0)
-                return r;
+        if (after) {
+                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, true, mask);
+                if (r < 0)
+                        return r;
+        }
 
         r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, mask);
         if (r < 0)
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
@@ -391,12 +391,6 @@ static int add_mount(
                 "SourcePath=%s\n",
                 source);
 
-        /* All mounts under /sysroot need to happen later, at initrd-fs.target time. IOW, it's not
-         * technically part of the basic initrd filesystem itself, and so shouldn't inherit the default
-         * Before=local-fs.target dependency. */
-        if (in_initrd() && path_startswith(where, "/sysroot"))
-                fprintf(f, "DefaultDependencies=no\n");
-
         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & AUTOMOUNT) &&
             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
@@ -411,9 +405,6 @@ static int add_mount(
                 SET_FLAG(flags, NOFAIL, true);
         }
 
-        if (!(flags & NOFAIL) && !(flags & AUTOMOUNT))
-                fprintf(f, "Before=%s\n", post);
-
         if (!(flags & AUTOMOUNT) && opts) {
                  r = write_after(f, opts);
                  if (r < 0)
