Merge pull request #11681 from yuwata/network-link-enslaved-operstate

[thirdparty/systemd.git] / src / remount-fs / remount-fs.c

diff --git a/src/remount-fs/remount-fs.c b/src/remount-fs/remount-fs.c
index af92ddb96cf5499a22c5a1692d0a9bf6cb7f11c1..0df29aa69ff0cb26f45b8fdbf9ebb6b55a8bedd4 100644 (file)
--- a/src/remount-fs/remount-fs.c
+++ b/src/remount-fs/remount-fs.c
@@ -8,6 +8,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include "env-util.h"
 #include "exit-status.h"
 #include "log.h"
 #include "main-func.h"
@@ -19,13 +20,62 @@
 #include "strv.h"
 #include "util.h"
 
-/* Goes through /etc/fstab and remounts all API file systems, applying
- * options that are in /etc/fstab that systemd might not have
- * respected */
+/* Goes through /etc/fstab and remounts all API file systems, applying options that are in /etc/fstab that systemd
+ * might not have respected */
+
+static int track_pid(Hashmap **h, const char *path, pid_t pid) {
+        _cleanup_free_ char *c = NULL;
+        int r;
+
+        assert(h);
+        assert(path);
+        assert(pid_is_valid(pid));
+
+        r = hashmap_ensure_allocated(h, NULL);
+        if (r < 0)
+                return log_oom();
+
+        c = strdup(path);
+        if (!c)
+                return log_oom();
+
+        r = hashmap_put(*h, PID_TO_PTR(pid), c);
+        if (r < 0)
+                return log_oom();
+
+        TAKE_PTR(c);
+        return 0;
+}
+
+static int do_remount(const char *path, bool force_rw, Hashmap **pids) {
+        pid_t pid;
+        int r;
+
+        log_debug("Remounting %s...", path);
+
+        r = safe_fork(force_rw ? "(remount-rw)" : "(remount)",
+                      FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                /* Child */
+                execv(MOUNT_PATH,
+                      STRV_MAKE(MOUNT_PATH,
+                                path,
+                                "-o",
+                                force_rw ? "remount,rw" : "remount"));
+                log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m");
+                _exit(EXIT_FAILURE);
+        }
+
+        /* Parent */
+        return track_pid(pids, path, pid);
+}
 
 static int run(int argc, char *argv[]) {
         _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
         _cleanup_endmntent_ FILE *f = NULL;
+        bool has_root = false;
         struct mntent* me;
         int r;
 
@@ -39,57 +89,43 @@ static int run(int argc, char *argv[]) {
 
         f = setmntent("/etc/fstab", "re");
         if (!f) {
-                if (errno == ENOENT)
-                        return 0;
-
-                return log_error_errno(errno, "Failed to open /etc/fstab: %m");
-        }
-
-        pids = hashmap_new(NULL);
-        if (!pids)
-                return log_oom();
-
-        while ((me = getmntent(f))) {
-                _cleanup_free_ char *s = NULL;
-                pid_t pid;
-                int k;
-
-                /* Remount the root fs, /usr and all API VFS */
-                if (!mount_point_is_api(me->mnt_dir) &&
-                    !path_equal(me->mnt_dir, "/") &&
-                    !path_equal(me->mnt_dir, "/usr"))
-                        continue;
-
-                log_debug("Remounting %s", me->mnt_dir);
-
-                r = safe_fork("(remount)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
-                if (r < 0)
-                        return r;
-                if (r == 0) {
-                        /* Child */
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to open /etc/fstab: %m");
+        } else
+                while ((me = getmntent(f))) {
+                        /* Remount the root fs, /usr, and all API VFSs */
+                        if (!mount_point_is_api(me->mnt_dir) &&
+                            !PATH_IN_SET(me->mnt_dir, "/", "/usr"))
+                                continue;
 
-                        execv(MOUNT_PATH, STRV_MAKE(MOUNT_PATH, me->mnt_dir, "-o", "remount"));
+                        if (path_equal(me->mnt_dir, "/"))
+                                has_root = true;
 
-                        log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m");
-                        _exit(EXIT_FAILURE);
+                        r = do_remount(me->mnt_dir, false, &pids);
+                        if (r < 0)
+                                return r;
                 }
 
-                /* Parent */
+        if (!has_root) {
+                /* The $SYSTEMD_REMOUNT_ROOT_RW environment variable is set by systemd-gpt-auto-generator to tell us
+                 * whether to remount things. We honour it only if there's no explicit line in /etc/fstab configured
+                 * which takes precedence. */
 
-                s = strdup(me->mnt_dir);
-                if (!s)
-                        return log_oom();
+                r = getenv_bool("SYSTEMD_REMOUNT_ROOT_RW");
+                if (r < 0 && r != -ENXIO)
+                        log_warning_errno(r, "Failed to parse $SYSTEMD_REMOUNT_ROOT_RW, ignoring: %m");
 
-                k = hashmap_put(pids, PID_TO_PTR(pid), s);
-                if (k < 0)
-                        return log_oom();
-                TAKE_PTR(s);
+                if (r > 0) {
+                        r = do_remount("/", true, &pids);
+                        if (r < 0)
+                                return r;
+                }
         }
 
         r = 0;
         while (!hashmap_isempty(pids)) {
-                siginfo_t si = {};
                 _cleanup_free_ char *s = NULL;
+                siginfo_t si = {};
 
                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
                         if (errno == EINTR)