mount: replace UNIT_DEPENDENCY_MOUNTINFO_OR_FILE with UNIT_DEPENDENCY_MOUNTINFO/UNIT_...

UNIT_DEPENDENCY_MOUNTINFO_OR_FILE was a bit strange as unlike the other flags
we don't know where the dependency came from exactly. Indeed its origin could
have been from the mount unit file or from /proc/self/mountinfo.

Instead this patch replaces UNIT_DEPENDENCY_MOUNTINFO_OR_FILE with 2 new
dependency flags: UNIT_DEPENDENCY_MOUNT_FILE and UNIT_DEPENDENCY_MOUNTINFO. The
former indicates that the dep is created from the unit file but unlike
UNIT_DEPENDENCY_FILE, it will be replaced by a dep with the
UNIT_DEPENDENCY_MOUNTINFO flag as soon as the kernel will make the mount
available in /proc/self/mountinfo.

diff --git a/src/core/mount.c b/src/core/mount.c
index f9c5c80e35ceb1044fc740ecf3bf35af00c39e36..d6bf009ada0bfbf8030ef9d62ae9b6b8f80b5b58 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -350,6 +350,7 @@ static int mount_add_mount_dependencies(Mount *m) {
 }
 
 static int mount_add_device_dependencies(Mount *m) {
+        UnitDependencyMask mask;
         MountParameters *p;
         UnitDependency dep;
         int r;
@@ -398,14 +399,17 @@ static int mount_add_device_dependencies(Mount *m) {
          * suddenly. */
         dep = mount_is_bound_to_device(m) ? UNIT_BINDS_TO : UNIT_REQUIRES;
 
-        r = unit_add_node_dependency(UNIT(m), p->what, dep, UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+        /* We always use 'what' from /proc/self/mountinfo if mounted */
+        mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
+
+        r = unit_add_node_dependency(UNIT(m), p->what, dep, mask);
         if (r < 0)
                 return r;
         if (r > 0)
                 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(dep), p->what);
 
         if (mount_propagate_stop(m)) {
-                r = unit_add_node_dependency(UNIT(m), p->what, UNIT_STOP_PROPAGATED_FROM, UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_node_dependency(UNIT(m), p->what, UNIT_STOP_PROPAGATED_FROM, mask);
                 if (r < 0)
                         return r;
                 if (r > 0)
@@ -413,7 +417,7 @@ static int mount_add_device_dependencies(Mount *m) {
                                        unit_dependency_to_string(UNIT_STOP_PROPAGATED_FROM), p->what);
         }
 
-        r = unit_add_blockdev_dependency(UNIT(m), p->what, UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+        r = unit_add_blockdev_dependency(UNIT(m), p->what, mask);
         if (r > 0)
                 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(UNIT_AFTER), p->what);
 
@@ -470,10 +474,7 @@ static bool mount_is_extrinsic(Unit *u) {
         return false;
 }
 
-static int mount_add_default_ordering_dependencies(
-                Mount *m,
-                MountParameters *p) {
-
+static int mount_add_default_ordering_dependencies(Mount *m, MountParameters *p, UnitDependencyMask mask) {
         const char *after, *before, *e;
         int r;
 
@@ -498,25 +499,23 @@ static int mount_add_default_ordering_dependencies(
         }
 
         if (!mount_is_nofail(m)) {
-                r = unit_add_dependency_by_name(UNIT(m), UNIT_BEFORE, before, true,
-                                                UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_dependency_by_name(UNIT(m), UNIT_BEFORE, before, /* add_reference= */ true, mask);
                 if (r < 0)
                         return r;
         }
 
         if (after) {
-                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, true,
-                                                UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, /* add_reference= */ true, mask);
                 if (r < 0)
                         return r;
         }
 
-        return unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS,
-                                                 SPECIAL_UMOUNT_TARGET, true,
-                                                 UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+        return unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET,
+                                                 /* add_reference= */ true, mask);
 }
 
 static int mount_add_default_dependencies(Mount *m) {
+        UnitDependencyMask mask;
         MountParameters *p;
         int r;
 
@@ -536,7 +535,9 @@ static int mount_add_default_dependencies(Mount *m) {
         if (!p)
                 return 0;
 
-        r = mount_add_default_ordering_dependencies(m, p);
+        mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
+
+        r = mount_add_default_ordering_dependencies(m, p, mask);
         if (r < 0)
                 return r;
 
@@ -546,8 +547,8 @@ static int mount_add_default_dependencies(Mount *m) {
                  * network.target, so that they are shut down only after this mount unit is
                  * stopped. */
 
-                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_NETWORK_TARGET, true,
-                                                UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_NETWORK_TARGET,
+                                                /* add_reference= */ true, mask);
                 if (r < 0)
                         return r;
 
@@ -556,17 +557,16 @@ static int mount_add_default_dependencies(Mount *m) {
                  * mounting network file systems, and whose purpose it is to delay this until the
                  * network is "up". */
 
-                r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_WANTS, UNIT_AFTER,
-                                                      SPECIAL_NETWORK_ONLINE_TARGET, true,
-                                                      UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_WANTS, UNIT_AFTER, SPECIAL_NETWORK_ONLINE_TARGET,
+                                                      /* add_reference= */ true, mask);
                 if (r < 0)
                         return r;
         }
 
         /* If this is a tmpfs mount then we have to unmount it before we try to deactivate swaps */
         if (streq_ptr(p->fstype, "tmpfs")) {
-                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_SWAP_TARGET, true,
-                                                UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+                r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_SWAP_TARGET,
+                                                /* add_reference= */ true, mask);
                 if (r < 0)
                         return r;
         }
@@ -614,7 +614,7 @@ static int mount_add_non_exec_dependencies(Mount *m) {
         /* We may be called due to this mount appearing in /proc/self/mountinfo, hence we clear all existing
          * dependencies that were initialized from the unit file but whose final value really depends on the
          * content of /proc/self/mountinfo. Some (such as m->where) might have become stale now. */
-        unit_remove_dependencies(UNIT(m), UNIT_DEPENDENCY_MOUNTINFO_OR_FILE);
+        unit_remove_dependencies(UNIT(m), UNIT_DEPENDENCY_MOUNTINFO | UNIT_DEPENDENCY_MOUNT_FILE);
 
         if (!m->where)
                 return 0;

diff --git a/src/core/unit-serialize.c b/src/core/unit-serialize.c
index a8fb40555008e47b245af5c8cbcbc4f3d3edf40c..e85b41a97d5ef03dca5f8fa7d399bf37e014677b 100644 (file)
--- a/src/core/unit-serialize.c
+++ b/src/core/unit-serialize.c
@@ -590,7 +590,8 @@ static void print_unit_dependency_mask(FILE *f, const char *kind, UnitDependency
                 { UNIT_DEPENDENCY_DEFAULT,            "default"            },
                 { UNIT_DEPENDENCY_UDEV,               "udev"               },
                 { UNIT_DEPENDENCY_PATH,               "path"               },
-                { UNIT_DEPENDENCY_MOUNTINFO_OR_FILE,  "mountinfo-or-file"  },
+                { UNIT_DEPENDENCY_MOUNT_FILE,         "mount-file"         },
+                { UNIT_DEPENDENCY_MOUNTINFO,          "mountinfo"          },
                 { UNIT_DEPENDENCY_PROC_SWAP,          "proc-swap"          },
                 { UNIT_DEPENDENCY_SLICE_PROPERTY,     "slice-property"     },
         };

diff --git a/src/core/unit.h b/src/core/unit.h
index 06ec7ea7b58945977a04b6a6f826466d8bccaf73..b34c59c3eba9d0fb669c36eaee257f9f12f08f4f 100644 (file)
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -79,17 +79,21 @@ typedef enum UnitDependencyMask {
         /* A dependency created because of some unit's RequiresMountsFor= setting */
         UNIT_DEPENDENCY_PATH               = 1 << 4,
 
-        /* A dependency created because of data read from /proc/self/mountinfo, but fallback to unit configuration
-         * sources */
-        UNIT_DEPENDENCY_MOUNTINFO_OR_FILE  = 1 << 5,
+        /* A dependency initially configured from the mount unit file however the dependency will be updated
+         * from /proc/self/mountinfo as soon as the kernel will make the entry for that mount available in
+         * the /proc file */
+        UNIT_DEPENDENCY_MOUNT_FILE         = 1 << 5,
+
+        /* A dependency created or updated because of data read from /proc/self/mountinfo */
+        UNIT_DEPENDENCY_MOUNTINFO          = 1 << 6,
 
         /* A dependency created because of data read from /proc/swaps and no other configuration source */
-        UNIT_DEPENDENCY_PROC_SWAP          = 1 << 6,
+        UNIT_DEPENDENCY_PROC_SWAP          = 1 << 7,
 
         /* A dependency for units in slices assigned by directly setting Slice= */
-        UNIT_DEPENDENCY_SLICE_PROPERTY     = 1 << 7,
+        UNIT_DEPENDENCY_SLICE_PROPERTY     = 1 << 8,
 
-        _UNIT_DEPENDENCY_MASK_FULL         = (1 << 8) - 1,
+        _UNIT_DEPENDENCY_MASK_FULL         = (1 << 9) - 1,
 } UnitDependencyMask;
 
 /* The Unit's dependencies[] hashmaps use this structure as value. It has the same size as a void pointer, and thus can