From 2047b2d0db643a168144b708cf58091ca47acb21 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Wed, 4 May 2016 10:10:57 -0400

Subject: [PATCH] shared/install: handle dangling aliases as an explicit case,

 report nicely

This fixes 'preset-all' with a unit that is a dangling symlink.

$ systemctl --root=/ preset-all

Unit syslog.service is an alias to a unit that is not present, ignoring.

Unit auditd.service is masked, ignoring.

Unit NetworkManager.service is masked, ignoring.

Cherry-picked from: 893275df36c8c358d3c0b851ca255a6169dac138

Resolves: #1375097

---

 src/libsystemd/sd-bus/bus-util.c |  2 ++

 src/shared/install.c             | 17 +++++++++++++----

 src/shared/install.h             |  1 +

 src/systemctl/systemctl.c        |  3 +++

 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/libsystemd/sd-bus/bus-util.c b/src/libsystemd/sd-bus/bus-util.c

index 75d0370..d357760 100644

--- a/src/libsystemd/sd-bus/bus-util.c

+++ b/src/libsystemd/sd-bus/bus-util.c

@@ -1897,6 +1897,8 @@ int bus_deserialize_and_dump_unit_file_changes(sd_bus_message *m, bool quiet, Un

                                 log_info("Removed symlink %s.", path);

                         else if (streq(type, "masked"))

                                 log_info("Unit %s is masked, ignoring.", path);

+                        else if (streq(type, "dangling"))

+                                log_info("Unit %s is an alias to a unit that is not present, ignoring.", path);

                         else

                                 log_notice("Manager reported unknown change type \"%s\" for %s.", type, path);

                 }

diff --git a/src/shared/install.c b/src/shared/install.c

index 62da52d..b0a29dd 100644

--- a/src/shared/install.c

+++ b/src/shared/install.c

@@ -1253,12 +1253,15 @@ static int install_info_traverse(

                         if (r < 0)

                                 return r;

+                        /* Try again, with the new target we found. */

                         r = unit_file_search(c, i, paths, root_dir, flags);

-                        if (r < 0)

-                                return r;

+                        if (r == -ENOENT)

+                                /* Translate error code to highlight this specific case */

+                                return -ENOLINK;

                 }

-                /* Try again, with the new target we found. */

+                if (r < 0)

+                        return r;

         }

         if (ret)

@@ -1528,7 +1531,9 @@ static int install_context_mark_for_removal(

                         return r;

                 r = install_info_traverse(scope, c, root_dir, paths, i, SEARCH_LOAD|SEARCH_FOLLOW_CONFIG_SYMLINKS, NULL);

-                if (r < 0)

+                if (r == -ENOLINK)

+                        return 0;

+                else if (r < 0)

                         return r;

                 if (i->type != UNIT_FILE_TYPE_REGULAR)

@@ -2405,6 +2410,9 @@ int unit_file_preset_all(

                         if (r == -ESHUTDOWN)

                                 r = unit_file_changes_add(changes, n_changes,

                                                           UNIT_FILE_IS_MASKED, de->d_name, NULL);

+                        else if (r == -ENOLINK)

+                                r = unit_file_changes_add(changes, n_changes,

+                                                          UNIT_FILE_IS_DANGLING, de->d_name, NULL);

                         if (r < 0)

                                 return r;

                 }

@@ -2539,6 +2547,7 @@ static const char* const unit_file_change_type_table[_UNIT_FILE_CHANGE_TYPE_MAX]

         [UNIT_FILE_SYMLINK] = "symlink",

         [UNIT_FILE_UNLINK] = "unlink",

         [UNIT_FILE_IS_MASKED] = "masked",

+        [UNIT_FILE_IS_DANGLING] = "dangling",

 };

 DEFINE_STRING_TABLE_LOOKUP(unit_file_change_type, UnitFileChangeType);

diff --git a/src/shared/install.h b/src/shared/install.h

index f0e3666..7e40445 100644

--- a/src/shared/install.h

+++ b/src/shared/install.h

@@ -61,6 +61,7 @@ typedef enum UnitFileChangeType {

         UNIT_FILE_SYMLINK,

         UNIT_FILE_UNLINK,

         UNIT_FILE_IS_MASKED,

+        UNIT_FILE_IS_DANGLING,

         _UNIT_FILE_CHANGE_TYPE_MAX,

         _UNIT_FILE_CHANGE_TYPE_INVALID = -1

 } UnitFileChangeType;

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c

index a688d69..39f0150 100644

--- a/src/systemctl/systemctl.c

+++ b/src/systemctl/systemctl.c

@@ -1955,6 +1955,9 @@ static void dump_unit_file_changes(const UnitFileChange *changes, unsigned n_cha

                 case UNIT_FILE_IS_MASKED:

                         log_info("Unit %s is masked, ignoring.", changes[i].path);

                         break;

+                case UNIT_FILE_IS_DANGLING:

+                        log_info("Unit %s is an alias to a unit that is not present, ignoring.", changes[i].path);

+                        break;

                 default:

                         assert_not_reached("bad change type");

                 }