Merge pull request #4877 from evverx/fix-machine-id

handle corrupted /etc/machine-id nicer

4 files changed, 14 insertions, 5 deletions

diff --git a/src/basic/path-util.h b/src/basic/path-util.h
index d2bc0d3b8e..d548f0c345 100644
--- a/src/basic/path-util.h
+++ b/src/basic/path-util.h
@@ -24,6 +24,7 @@
 #include <stddef.h>
 
 #include "macro.h"
+#include "string-util.h"
 #include "time-util.h"
 
 #define DEFAULT_PATH_NORMAL "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c
index c83bb561c7..df3cc74b98 100644
--- a/src/core/machine-id-setup.c
+++ b/src/core/machine-id-setup.c
@@ -146,14 +146,18 @@ int machine_id_setup(const char *root, sd_id128_t machine_id, sd_id128_t *ret) {
                 r = generate_machine_id(root, &machine_id);
                 if (r < 0)
                         return r;
+        }
 
+        if (writable) {
                 if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
-                        return log_error_errno(errno, "Failed to seek: %m");
-        }
+                        return log_error_errno(errno, "Failed to seek %s: %m", etc_machine_id);
+
+                if (ftruncate(fd, 0) < 0)
+                        return log_error_errno(errno, "Failed to truncate %s: %m", etc_machine_id);
 
-        if (writable)
                 if (id128_write_fd(fd, ID128_PLAIN, machine_id, true) >= 0)
                         goto finish;
+        }
 
         fd = safe_close(fd);
 
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
index 337eae24b4..e6d45c18e3 100644
--- a/src/libsystemd/sd-id128/id128-util.c
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -186,7 +186,7 @@ int id128_write_fd(int fd, Id128Format f, sd_id128_t id, bool do_sync) {
 int id128_write(const char *p, Id128Format f, sd_id128_t id, bool do_sync) {
         _cleanup_close_ int fd = -1;
 
-        fd = open(p, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
+        fd = open(p, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_TRUNC, 0444);
         if (fd < 0)
                 return -errno;
 
diff --git a/src/machine-id-setup/machine-id-setup-main.c b/src/machine-id-setup/machine-id-setup-main.c
index cc9b1b38fe..2244b1cc76 100644
--- a/src/machine-id-setup/machine-id-setup-main.c
+++ b/src/machine-id-setup/machine-id-setup-main.c
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "id128-util.h"
 #include "log.h"
 #include "machine-id-setup.h"
 #include "path-util.h"
@@ -118,11 +119,14 @@ int main(int argc, char *argv[]) {
                 goto finish;
 
         if (arg_commit) {
+                const char *etc_machine_id;
+
                 r = machine_id_commit(arg_root);
                 if (r < 0)
                         goto finish;
 
-                r = sd_id128_get_machine(&id);
+                etc_machine_id = prefix_roota(arg_root, "/etc/machine-id");
+                r = id128_read(etc_machine_id, ID128_PLAIN, &id);
                 if (r < 0) {
                         log_error_errno(r, "Failed to read machine ID back: %m");
                         goto finish;