coredump: simplify a few things by allocating small fields on the stack rather than...

[elogind.git] / src / core / machine-id-setup.c

diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c
index efb074fcbda14d9ce8d78b084ee4f082196ea58d..671003820b77b2a815ddbf37a8b60be1ec096196 100644 (file)
--- a/src/core/machine-id-setup.c
+++ b/src/core/machine-id-setup.c
@@ -141,10 +141,8 @@ static int generate(char id[34], const char *root) {
 
         /* If that didn't work, generate a random machine id */
         r = sd_id128_randomize(&buf);
-        if (r < 0) {
-                log_error("Failed to open /dev/urandom: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to open /dev/urandom: %m");
 
         for (p = buf.bytes, q = id; p < buf.bytes + sizeof(buf); p++, q += 2) {
                 q[0] = hexchar(*p >> 4);
@@ -162,7 +160,7 @@ static int generate(char id[34], const char *root) {
 int machine_id_setup(const char *root) {
         const char *etc_machine_id, *run_machine_id;
         _cleanup_close_ int fd = -1;
-        bool writable = false;
+        bool writable = true;
         struct stat st;
         char id[34]; /* 32 + \n + \0 */
         int r;
@@ -186,12 +184,19 @@ int machine_id_setup(const char *root) {
 
                 mkdir_parents(etc_machine_id, 0755);
                 fd = open(etc_machine_id, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
-                if (fd >= 0)
-                        writable = true;
-                else {
+                if (fd < 0) {
+                        int old_errno = errno;
+
                         fd = open(etc_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY);
                         if (fd < 0) {
-                                log_error("Cannot open %s: %m", etc_machine_id);
+                                if (old_errno == EROFS && errno == ENOENT)
+                                        log_error("System cannot boot: Missing /etc/machine-id and /etc is mounted read-only.\n"
+                                                  "Booting up is supported only when:\n"
+                                                  "1) /etc/machine-id exists and is populated.\n"
+                                                  "2) /etc/machine-id exists and is empty.\n"
+                                                  "3) /etc/machine-id is missing and /etc is writable.\n");
+                                else
+                                        log_error_errno(errno, "Cannot open %s: %m", etc_machine_id);
                                 return -errno;
                         }
 
@@ -199,10 +204,8 @@ int machine_id_setup(const char *root) {
                 }
         }
 
-        if (fstat(fd, &st) < 0) {
-                log_error("fstat() failed: %m");
-                return -errno;
-        }
+        if (fstat(fd, &st) < 0)
+                return log_error_errno(errno, "fstat() failed: %m");
 
         if (S_ISREG(st.st_mode))
                 if (loop_read(fd, id, 33, false) == 33 && id[32] == '\n') {
@@ -235,7 +238,7 @@ int machine_id_setup(const char *root) {
                 r = write_string_file(run_machine_id, id);
         }
         if (r < 0) {
-                log_error("Cannot write %s: %s", run_machine_id, strerror(-r));
+                log_error_errno(r, "Cannot write %s: %m", run_machine_id);
                 unlink(run_machine_id);
                 return r;
         }
@@ -243,7 +246,7 @@ int machine_id_setup(const char *root) {
         /* And now, let's mount it over */
         r = mount(run_machine_id, etc_machine_id, NULL, MS_BIND, NULL);
         if (r < 0) {
-                log_error("Failed to mount %s: %m", etc_machine_id);
+                log_error_errno(errno, "Failed to mount %s: %m", etc_machine_id);
                 unlink_noerrno(run_machine_id);
                 return -errno;
         }
@@ -252,7 +255,7 @@ int machine_id_setup(const char *root) {
 
         /* Mark the mount read-only */
         if (mount(NULL, etc_machine_id, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0)
-                log_warning("Failed to make transient %s read-only: %m", etc_machine_id);
+                log_warning_errno(errno, "Failed to make transient %s read-only: %m", etc_machine_id);
 
         return 0;
 }