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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
commit | 19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch) | |
tree | d59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/remount-fs | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/remount-fs')
-rw-r--r-- | src/remount-fs/remount-fs.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/remount-fs/remount-fs.c b/src/remount-fs/remount-fs.c new file mode 100644 index 0000000..0bac355 --- /dev/null +++ b/src/remount-fs/remount-fs.c @@ -0,0 +1,156 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> +#include <mntent.h> +#include <string.h> +#include <sys/prctl.h> +#include <sys/stat.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "env-util.h" +#include "exit-status.h" +#include "log.h" +#include "main-func.h" +#include "mount-setup.h" +#include "mount-util.h" +#include "path-util.h" +#include "process-util.h" +#include "signal-util.h" +#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 */ + +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 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; + + log_setup_service(); + + if (argc > 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "This program takes no arguments."); + + umask(0022); + + f = setmntent("/etc/fstab", "re"); + if (!f) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to open /etc/fstab: %m"); + } else { + while ((me = getmntent(f))) { + pid_t pid; + + /* Remount the root fs, /usr and all API VFS */ + if (!mount_point_is_api(me->mnt_dir) && + !PATH_IN_SET(me->mnt_dir, "/", "/usr")) + continue; + + log_debug("Remounting %s...", me->mnt_dir); + + if (path_equal(me->mnt_dir, "/")) + has_root = true; + + 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 */ + execv(MOUNT_PATH, STRV_MAKE(MOUNT_PATH, me->mnt_dir, "-o", "remount")); + log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m"); + _exit(EXIT_FAILURE); + } + + /* Parent */ + r = track_pid(&pids, me->mnt_dir, pid); + if (r < 0) + return r; + } + } + + 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. */ + + r = getenv_bool("SYSTEMD_REMOUNT_ROOT_RW"); + if (r > 0) { + pid_t pid; + + log_debug("Remounting / writable..."); + + r = safe_fork("(remount-rw)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid); + if (r < 0) + return r; + if (r == 0) { + /* Child */ + execv(MOUNT_PATH, STRV_MAKE(MOUNT_PATH, "/", "-o", "remount,rw")); + log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m"); + _exit(EXIT_FAILURE); + } + + r = track_pid(&pids, "/", pid); + if (r < 0) + return r; + + } else if (r < 0 && r != -ENXIO) + log_warning_errno(r, "Failed to parse $SYSTEMD_REMOUNT_ROOT_RW, ignoring: %m"); + } + + r = 0; + while (!hashmap_isempty(pids)) { + _cleanup_free_ char *s = NULL; + siginfo_t si = {}; + + if (waitid(P_ALL, 0, &si, WEXITED) < 0) { + if (errno == EINTR) + continue; + + return log_error_errno(errno, "waitid() failed: %m"); + } + + s = hashmap_remove(pids, PID_TO_PTR(si.si_pid)); + if (s && + !is_clean_exit(si.si_code, si.si_status, EXIT_CLEAN_COMMAND, NULL)) { + if (si.si_code == CLD_EXITED) + log_error(MOUNT_PATH " for %s exited with exit status %i.", s, si.si_status); + else + log_error(MOUNT_PATH " for %s terminated by signal %s.", s, signal_to_string(si.si_status)); + + r = -ENOEXEC; + } + } + + return r; +} + +DEFINE_MAIN_FUNCTION(run); |