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Merge pull request #11226 from keszybz/enable-remount-fs-dynamically

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Enable systemd-remount-fs.service dynamically
This commit is contained in:
Lennart Poettering
2019-02-18 12:46:31 +01:00
committed by GitHub
parent 8c7840c5ee 5ff8da1057
commit 4d422d1f9e
13 changed files with 142 additions and 109 deletions
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src/basic/special.h
+2
View File
@@ -76,9 +76,11 @@
/* Magic early boot services */
#define SPECIAL_FSCK_SERVICE "systemd-fsck@.service"
#define SPECIAL_FSCK_ROOT_SERVICE "systemd-fsck-root.service"
#define SPECIAL_QUOTACHECK_SERVICE "systemd-quotacheck.service"
#define SPECIAL_QUOTAON_SERVICE "quotaon.service"
#define SPECIAL_REMOUNT_FS_SERVICE "systemd-remount-fs.service"
#define SPECIAL_VOLATILE_ROOT_SERVICE "systemd-volatile-root.service"
/* Services systemd relies on */
#define SPECIAL_DBUS_SERVICE "dbus.service"
src/fstab-generator/fstab-generator.c
+15 -37
View File
@@ -518,6 +518,8 @@ static int parse_fstab(bool initrd) {
int r = 0;
fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
log_debug("Parsing %s...", fstab_path);
f = setmntent(fstab_path, "re");
if (!f) {
if (errno == ENOENT)
@@ -720,23 +722,14 @@ static int add_sysroot_usr_mount(void) {
}
static int add_volatile_root(void) {
const char *from, *to;
/* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
* requested, leaving only /usr from the root mount inside. */
if (arg_volatile_mode != VOLATILE_YES)
return 0;
/* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
* requested, leaving only /usr from the root mount inside. */
from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
(void) mkdir_parents(to, 0755);
if (symlink(from, to) < 0)
return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
return 0;
return generator_add_symlink(arg_dest, SPECIAL_INITRD_ROOT_FS_TARGET, "requires",
SYSTEM_DATA_UNIT_PATH "/" SPECIAL_VOLATILE_ROOT_SERVICE);
}
static int add_volatile_var(void) {
@@ -868,7 +861,7 @@ static int determine_root(void) {
}
static int run(const char *dest, const char *dest_early, const char *dest_late) {
int r;
int r, r2 = 0, r3 = 0;
assert_se(arg_dest = dest);
assert_se(arg_dest_late = dest_late);
@@ -881,42 +874,27 @@ static int run(const char *dest, const char *dest_early, const char *dest_late)
/* Always honour root= and usr= in the kernel command line if we are in an initrd */
if (in_initrd()) {
int k;
r = add_sysroot_mount();
k = add_sysroot_usr_mount();
if (k < 0)
r = k;
r2 = add_sysroot_usr_mount();
k = add_volatile_root();
if (k < 0)
r = k;
r3 = add_volatile_root();
} else
r = add_volatile_var();
/* Honour /etc/fstab only when that's enabled */
if (arg_fstab_enabled) {
int k;
log_debug("Parsing /etc/fstab");
/* Parse the local /etc/fstab, possibly from the initrd */
k = parse_fstab(false);
if (k < 0)
r = k;
r2 = parse_fstab(false);
/* If running in the initrd also parse the /etc/fstab from the host */
if (in_initrd()) {
log_debug("Parsing /sysroot/etc/fstab");
k = parse_fstab(true);
if (k < 0)
r = k;
}
if (in_initrd())
r3 = parse_fstab(true);
else
r3 = generator_enable_remount_fs_service(arg_dest);
}
return r;
return r < 0 ? r : r2 < 0 ? r2 : r3;
}
DEFINE_MAIN_GENERATOR_FUNCTION(run);
src/gpt-auto-generator/gpt-auto-generator.c
+5 -2
View File
@@ -467,13 +467,13 @@ static int add_root_rw(DissectedPartition *p) {
return 0;
}
(void) generator_enable_remount_fs_service(arg_dest);
path = strjoina(arg_dest, "/systemd-remount-fs.service.d/50-remount-rw.conf");
(void) mkdir_parents(path, 0755);
r = write_string_file(path,
"# Automatically generated by systemd-gpt-generator\n\n"
"[Unit]\n"
"ConditionPathExists=\n\n" /* We need to turn off the ConditionPathExist= in the main unit file */
"[Service]\n"
"Environment=SYSTEMD_REMOUNT_ROOT_RW=1\n",
WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_NOFOLLOW);
@@ -678,6 +678,9 @@ static int add_root_mount(void) {
return r;
}
/* Note that we do not need to enable systemd-remount-fs.service here. If
* /etc/fstab exists, systemd-fstab-generator will pull it in for us. */
return add_mount(
"root",
"/dev/gpt-auto-root",
src/remount-fs/remount-fs.c
+35 -39
View File
@@ -47,6 +47,31 @@ static int track_pid(Hashmap **h, const char *path, pid_t pid) {
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;
@@ -66,36 +91,20 @@ static int run(int argc, char *argv[]) {
if (!f) {
if (errno != ENOENT)
return log_error_errno(errno, "Failed to open /etc/fstab: %m");
} else {
} else
while ((me = getmntent(f))) {
pid_t pid;
/* Remount the root fs, /usr and all API VFS */
/* 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;
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);
r = do_remount(me->mnt_dir, false, &pids);
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
@@ -103,27 +112,14 @@ static int run(int argc, char *argv[]) {
* 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)
if (r < 0 && r != -ENXIO)
log_warning_errno(r, "Failed to parse $SYSTEMD_REMOUNT_ROOT_RW, ignoring: %m");
if (r > 0) {
r = do_remount("/", true, &pids);
if (r < 0)
return r;
}
}
r = 0;
src/shared/generator.c
+15 -8
View File
@@ -55,13 +55,14 @@ int generator_open_unit_file(
return 0;
}
int generator_add_symlink(const char *root, const char *dst, const char *dep_type, const char *src) {
/* Adds a symlink from <dst>.<dep_type>.d/ to ../<src> */
int generator_add_symlink(const char *dir, const char *dst, const char *dep_type, const char *src) {
/* Adds a symlink from <dst>.<dep_type>/ to <src> (if src is absolute)
* or ../<src> (otherwise). */
const char *from, *to;
from = strjoina("../", src);
to = strjoina(root, "/", dst, ".", dep_type, "/", src);
from = path_is_absolute(src) ? src : strjoina("../", src);
to = strjoina(dir, "/", dst, ".", dep_type, "/", basename(src));
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0)
@@ -85,7 +86,7 @@ static int write_fsck_sysroot_service(const char *dir, const char *what) {
if (!escaped2)
return log_oom();
unit = strjoina(dir, "/systemd-fsck-root.service");
unit = strjoina(dir, "/"SPECIAL_FSCK_ROOT_SERVICE);
log_debug("Creating %s", unit);
r = unit_name_from_path(what, ".device", &device);
@@ -157,10 +158,10 @@ int generator_write_fsck_deps(
if (path_equal(where, "/")) {
const char *lnk;
lnk = strjoina(dir, "/" SPECIAL_LOCAL_FS_TARGET ".wants/systemd-fsck-root.service");
lnk = strjoina(dir, "/" SPECIAL_LOCAL_FS_TARGET ".wants/"SPECIAL_FSCK_ROOT_SERVICE);
mkdir_parents(lnk, 0755);
if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-fsck-root.service", lnk) < 0)
if (symlink(SYSTEM_DATA_UNIT_PATH "/"SPECIAL_FSCK_ROOT_SERVICE, lnk) < 0)
return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
} else {
@@ -172,7 +173,7 @@ int generator_write_fsck_deps(
if (r < 0)
return r;
fsck = "systemd-fsck-root.service";
fsck = SPECIAL_FSCK_ROOT_SERVICE;
} else {
r = unit_name_from_path_instance("systemd-fsck", what, ".service", &_fsck);
if (r < 0)
@@ -498,6 +499,12 @@ int generator_hook_up_growfs(
return generator_add_symlink(dir, where_unit, "wants", unit);
}
int generator_enable_remount_fs_service(const char *dir) {
/* Pull in systemd-remount-fs.service */
return generator_add_symlink(dir, SPECIAL_LOCAL_FS_TARGET, "wants",
SYSTEM_DATA_UNIT_PATH "/" SPECIAL_REMOUNT_FS_SERVICE);
}
void log_setup_generator(void) {
log_set_prohibit_ipc(true);
log_setup_service();
src/shared/generator.h
+3 -1
View File
@@ -11,7 +11,7 @@ int generator_open_unit_file(
const char *name,
FILE **file);
int generator_add_symlink(const char *root, const char *dst, const char *dep_type, const char *src);
int generator_add_symlink(const char *dir, const char *dst, const char *dep_type, const char *src);
int generator_write_fsck_deps(
FILE *f,
@@ -50,6 +50,8 @@ int generator_hook_up_growfs(
const char *where,
const char *target);
int generator_enable_remount_fs_service(const char *dir);
void log_setup_generator(void);
/* Similar to DEFINE_MAIN_FUNCTION, but initializes logging and assigns positional arguments. */
src/test/test-unit-name.c
+1 -1
View File
@@ -759,7 +759,7 @@ static void test_unit_name_from_dbus_path(void) {
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dcoredump_2esocket", 0, "systemd-coredump.socket");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dcoredump_400_2eservice", 0, "systemd-coredump@0.service");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dfirstboot_2eservice", 0, "systemd-firstboot.service");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dfsck_2droot_2eservice", 0, "systemd-fsck-root.service");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dfsck_2droot_2eservice", 0, SPECIAL_FSCK_ROOT_SERVICE);
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dhwdb_2dupdate_2eservice", 0, "systemd-hwdb-update.service");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dinitctl_2eservice", 0, "systemd-initctl.service");
test_unit_name_from_dbus_path_one("/org/freedesktop/systemd1/unit/systemd_2dinitctl_2esocket", 0, "systemd-initctl.socket");