From 58ff64cdf05ad234674389e04fbe449e8895a071 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Fri, 7 Jul 2017 18:57:08 -0400 Subject: [PATCH] (backport) nspawn: Move cgroup mount stuff from nspawn-mount.c to nspawn-cgroup.c Change-Id: Iaf44ed696c287b1cc0aa7a8c79773095a3c1ecc6 --- src/nspawn/nspawn-cgroup.c | 417 +++++++++++++++++++++++++++++++++++++++++++++ src/nspawn/nspawn-cgroup.h | 3 + src/nspawn/nspawn-mount.c | 415 +------------------------------------------- src/nspawn/nspawn-mount.h | 5 +- 4 files changed, 423 insertions(+), 417 deletions(-) diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c index d8a39a6..0be9119 100644 --- a/src/nspawn/nspawn-cgroup.c +++ b/src/nspawn/nspawn-cgroup.c @@ -5,12 +5,16 @@ #include "alloc-util.h" #include "fd-util.h" #include "fileio.h" +#include "fs-util.h" #include "mkdir.h" #include "mount-util.h" #include "nspawn-cgroup.h" +#include "nspawn-mount.h" +#include "path-util.h" #include "rm-rf.h" #include "string-util.h" #include "strv.h" +#include "user-util.h" #include "util.h" static int chown_cgroup_path(const char *path, uid_t uid_shift) { @@ -188,3 +192,416 @@ int create_subcgroup(pid_t pid, bool keep_unit, CGroupUnified unified_requested) (void) cg_enable_everywhere(supported, supported, cgroup); return 0; } + +/* Retrieve existing subsystems. This function is called in a new cgroup + * namespace. + */ +static int get_process_controllers(Set **ret) { + _cleanup_set_free_free_ Set *controllers = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(ret); + + controllers = set_new(&string_hash_ops); + if (!controllers) + return -ENOMEM; + + f = fopen("/proc/self/cgroup", "re"); + if (!f) + return errno == ENOENT ? -ESRCH : -errno; + + for (;;) { + _cleanup_free_ char *line = NULL; + char *e, *l; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + break; + + l = strchr(line, ':'); + if (!l) + continue; + + l++; + e = strchr(l, ':'); + if (!e) + continue; + + *e = 0; + + if (STR_IN_SET(l, "", "name=systemd", "name=unified")) + continue; + + r = set_put_strdup(controllers, l); + if (r < 0) + return r; + } + + *ret = TAKE_PTR(controllers); + + return 0; +} + +static int mount_legacy_cgroup_hierarchy( + const char *dest, + const char *controller, + const char *hierarchy, + bool read_only) { + + const char *to, *fstype, *opts; + int r; + + to = strjoina(strempty(dest), "/sys/fs/cgroup/", hierarchy); + + r = path_is_mount_point(to, dest, 0); + if (r < 0 && r != -ENOENT) + return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to); + if (r > 0) + return 0; + + mkdir_p(to, 0755); + + /* The superblock mount options of the mount point need to be + * identical to the hosts', and hence writable... */ + if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_HYBRID)) { + fstype = "cgroup2"; + opts = NULL; + } else if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_LEGACY)) { + fstype = "cgroup"; + opts = "none,name=systemd,xattr"; + } else { + fstype = "cgroup"; + opts = controller; + } + + r = mount_verbose(LOG_ERR, "cgroup", to, fstype, MS_NOSUID|MS_NOEXEC|MS_NODEV, opts); + if (r < 0) + return r; + + /* ... hence let's only make the bind mount read-only, not the superblock. */ + if (read_only) { + r = mount_verbose(LOG_ERR, NULL, to, NULL, + MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); + if (r < 0) + return r; + } + + return 1; +} + +/* Mount a legacy cgroup hierarchy when cgroup namespaces are supported. */ +static int mount_legacy_cgns_supported( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context) { + + _cleanup_set_free_free_ Set *controllers = NULL; + const char *cgroup_root = "/sys/fs/cgroup", *c; + int r; + + (void) mkdir_p(cgroup_root, 0755); + + /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ + r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); + if (r == 0) { + _cleanup_free_ char *options = NULL; + + /* When cgroup namespaces are enabled and user namespaces are + * used then the mount of the cgroupfs is done *inside* the new + * user namespace. We're root in the new user namespace and the + * kernel will happily translate our uid/gid to the correct + * uid/gid as seen from e.g. /proc/1/mountinfo. So we simply + * pass uid 0 and not uid_shift to tmpfs_patch_options(). + */ + r = tmpfs_patch_options("mode=755", 0, selinux_apifs_context, &options); + if (r < 0) + return log_oom(); + + r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", + MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); + if (r < 0) + return r; + } + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) + goto skip_controllers; + + r = get_process_controllers(&controllers); + if (r < 0) + return log_error_errno(r, "Failed to determine cgroup controllers: %m"); + + for (;;) { + _cleanup_free_ const char *controller = NULL; + + controller = set_steal_first(controllers); + if (!controller) + break; + + r = mount_legacy_cgroup_hierarchy("", controller, controller, !userns); + if (r < 0) + return r; + + /* When multiple hierarchies are co-mounted, make their + * constituting individual hierarchies a symlink to the + * co-mount. + */ + c = controller; + for (;;) { + _cleanup_free_ char *target = NULL, *tok = NULL; + + r = extract_first_word(&c, &tok, ",", 0); + if (r < 0) + return log_error_errno(r, "Failed to extract co-mounted cgroup controller: %m"); + if (r == 0) + break; + + if (streq(controller, tok)) + break; + + target = prefix_root("/sys/fs/cgroup/", tok); + if (!target) + return log_oom(); + + r = symlink_idempotent(controller, target); + if (r == -EINVAL) + return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); + if (r < 0) + return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); + } + } + +skip_controllers: + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); + if (r < 0) + return r; + } + + r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); + if (r < 0) + return r; + + if (!userns) + return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL, + MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); + + return 0; +} + +/* Mount legacy cgroup hierarchy when cgroup namespaces are unsupported. */ +static int mount_legacy_cgns_unsupported( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context) { + + _cleanup_set_free_free_ Set *controllers = NULL; + const char *cgroup_root; + int r; + + cgroup_root = prefix_roota(dest, "/sys/fs/cgroup"); + + (void) mkdir_p(cgroup_root, 0755); + + /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ + r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); + if (r == 0) { + _cleanup_free_ char *options = NULL; + + r = tmpfs_patch_options("mode=755", uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &options); + if (r < 0) + return log_oom(); + + r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", + MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); + if (r < 0) + return r; + } + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) + goto skip_controllers; + + r = cg_kernel_controllers(&controllers); + if (r < 0) + return log_error_errno(r, "Failed to determine cgroup controllers: %m"); + + for (;;) { + _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL; + + controller = set_steal_first(controllers); + if (!controller) + break; + + origin = prefix_root("/sys/fs/cgroup/", controller); + if (!origin) + return log_oom(); + + r = readlink_malloc(origin, &combined); + if (r == -EINVAL) { + /* Not a symbolic link, but directly a single cgroup hierarchy */ + + r = mount_legacy_cgroup_hierarchy(dest, controller, controller, true); + if (r < 0) + return r; + + } else if (r < 0) + return log_error_errno(r, "Failed to read link %s: %m", origin); + else { + _cleanup_free_ char *target = NULL; + + target = prefix_root(dest, origin); + if (!target) + return log_oom(); + + /* A symbolic link, a combination of controllers in one hierarchy */ + + if (!filename_is_valid(combined)) { + log_warning("Ignoring invalid combined hierarchy %s.", combined); + continue; + } + + r = mount_legacy_cgroup_hierarchy(dest, combined, combined, true); + if (r < 0) + return r; + + r = symlink_idempotent(combined, target); + if (r == -EINVAL) + return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); + if (r < 0) + return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); + } + } + +skip_controllers: + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); + if (r < 0) + return r; + } + + r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); + if (r < 0) + return r; + + return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL, + MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); +} + +static int mount_unified_cgroups(const char *dest) { + const char *p; + int r; + + assert(dest); + + p = prefix_roota(dest, "/sys/fs/cgroup"); + + (void) mkdir_p(p, 0755); + + r = path_is_mount_point(p, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if %s is mounted already: %m", p); + if (r > 0) { + p = prefix_roota(dest, "/sys/fs/cgroup/cgroup.procs"); + if (access(p, F_OK) >= 0) + return 0; + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine if mount point %s contains the unified cgroup hierarchy: %m", p); + + log_error("%s is already mounted but not a unified cgroup hierarchy. Refusing.", p); + return -EINVAL; + } + + return mount_verbose(LOG_ERR, "cgroup", p, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); +} + +int mount_cgroups( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context, + bool use_cgns) { + + if (unified_requested >= CGROUP_UNIFIED_ALL) + return mount_unified_cgroups(dest); + if (use_cgns) + return mount_legacy_cgns_supported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); + + return mount_legacy_cgns_unsupported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); +} + +static int mount_systemd_cgroup_writable_one(const char *root, const char *own) { + int r; + + assert(root); + assert(own); + + /* Make our own cgroup a (writable) bind mount */ + r = mount_verbose(LOG_ERR, own, own, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + /* And then remount the systemd cgroup root read-only */ + return mount_verbose(LOG_ERR, NULL, root, NULL, + MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); +} + +int mount_systemd_cgroup_writable( + const char *dest, + CGroupUnified unified_requested) { + + _cleanup_free_ char *own_cgroup_path = NULL; + const char *root, *own; + int r; + + assert(dest); + + r = cg_pid_get_path(NULL, 0, &own_cgroup_path); + if (r < 0) + return log_error_errno(r, "Failed to determine our own cgroup path: %m"); + + /* If we are living in the top-level, then there's nothing to do... */ + if (path_equal(own_cgroup_path, "/")) + return 0; + + if (unified_requested >= CGROUP_UNIFIED_ALL) { + + root = prefix_roota(dest, "/sys/fs/cgroup"); + own = strjoina(root, own_cgroup_path); + + } else { + + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + root = prefix_roota(dest, "/sys/fs/cgroup/unified"); + own = strjoina(root, own_cgroup_path); + + r = mount_systemd_cgroup_writable_one(root, own); + if (r < 0) + return r; + } + + root = prefix_roota(dest, "/sys/fs/cgroup/systemd"); + own = strjoina(root, own_cgroup_path); + } + + return mount_systemd_cgroup_writable_one(root, own); +} diff --git a/src/nspawn/nspawn-cgroup.h b/src/nspawn/nspawn-cgroup.h index 6783c3a..035e8fb 100644 --- a/src/nspawn/nspawn-cgroup.h +++ b/src/nspawn/nspawn-cgroup.h @@ -9,3 +9,6 @@ int chown_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift); int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift); int create_subcgroup(pid_t pid, bool keep_unit, CGroupUnified unified_requested); + +int mount_cgroups(const char *dest, CGroupUnified unified_requested, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, bool use_cgns); +int mount_systemd_cgroup_writable(const char *dest, CGroupUnified unified_requested); diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c index 2d046ce..9cd3c62 100644 --- a/src/nspawn/nspawn-mount.c +++ b/src/nspawn/nspawn-mount.c @@ -327,7 +327,7 @@ int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_onl return 0; } -static int tmpfs_patch_options( +int tmpfs_patch_options( const char *options, uid_t uid_shift, const char *selinux_apifs_context, @@ -856,419 +856,6 @@ int mount_custom( return 0; } -/* Retrieve existing subsystems. This function is called in a new cgroup - * namespace. - */ -static int get_process_controllers(Set **ret) { - _cleanup_set_free_free_ Set *controllers = NULL; - _cleanup_fclose_ FILE *f = NULL; - int r; - - assert(ret); - - controllers = set_new(&string_hash_ops); - if (!controllers) - return -ENOMEM; - - f = fopen("/proc/self/cgroup", "re"); - if (!f) - return errno == ENOENT ? -ESRCH : -errno; - - for (;;) { - _cleanup_free_ char *line = NULL; - char *e, *l; - - r = read_line(f, LONG_LINE_MAX, &line); - if (r < 0) - return r; - if (r == 0) - break; - - l = strchr(line, ':'); - if (!l) - continue; - - l++; - e = strchr(l, ':'); - if (!e) - continue; - - *e = 0; - - if (STR_IN_SET(l, "", "name=systemd", "name=unified")) - continue; - - r = set_put_strdup(controllers, l); - if (r < 0) - return r; - } - - *ret = TAKE_PTR(controllers); - - return 0; -} - -static int mount_legacy_cgroup_hierarchy( - const char *dest, - const char *controller, - const char *hierarchy, - bool read_only) { - - const char *to, *fstype, *opts; - int r; - - to = strjoina(strempty(dest), "/sys/fs/cgroup/", hierarchy); - - r = path_is_mount_point(to, dest, 0); - if (r < 0 && r != -ENOENT) - return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to); - if (r > 0) - return 0; - - mkdir_p(to, 0755); - - /* The superblock mount options of the mount point need to be - * identical to the hosts', and hence writable... */ - if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_HYBRID)) { - fstype = "cgroup2"; - opts = NULL; - } else if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_LEGACY)) { - fstype = "cgroup"; - opts = "none,name=systemd,xattr"; - } else { - fstype = "cgroup"; - opts = controller; - } - - r = mount_verbose(LOG_ERR, "cgroup", to, fstype, MS_NOSUID|MS_NOEXEC|MS_NODEV, opts); - if (r < 0) - return r; - - /* ... hence let's only make the bind mount read-only, not the superblock. */ - if (read_only) { - r = mount_verbose(LOG_ERR, NULL, to, NULL, - MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); - if (r < 0) - return r; - } - - return 1; -} - -/* Mount a legacy cgroup hierarchy when cgroup namespaces are supported. */ -static int mount_legacy_cgns_supported( - const char *dest, - CGroupUnified unified_requested, - bool userns, - uid_t uid_shift, - uid_t uid_range, - const char *selinux_apifs_context) { - - _cleanup_set_free_free_ Set *controllers = NULL; - const char *cgroup_root = "/sys/fs/cgroup", *c; - int r; - - (void) mkdir_p(cgroup_root, 0755); - - /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ - r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); - if (r < 0) - return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); - if (r == 0) { - _cleanup_free_ char *options = NULL; - - /* When cgroup namespaces are enabled and user namespaces are - * used then the mount of the cgroupfs is done *inside* the new - * user namespace. We're root in the new user namespace and the - * kernel will happily translate our uid/gid to the correct - * uid/gid as seen from e.g. /proc/1/mountinfo. So we simply - * pass uid 0 and not uid_shift to tmpfs_patch_options(). - */ - r = tmpfs_patch_options("mode=755", 0, selinux_apifs_context, &options); - if (r < 0) - return log_oom(); - - r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", - MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); - if (r < 0) - return r; - } - - r = cg_all_unified(); - if (r < 0) - return r; - if (r > 0) - goto skip_controllers; - - r = get_process_controllers(&controllers); - if (r < 0) - return log_error_errno(r, "Failed to determine cgroup controllers: %m"); - - for (;;) { - _cleanup_free_ const char *controller = NULL; - - controller = set_steal_first(controllers); - if (!controller) - break; - - r = mount_legacy_cgroup_hierarchy("", controller, controller, !userns); - if (r < 0) - return r; - - /* When multiple hierarchies are co-mounted, make their - * constituting individual hierarchies a symlink to the - * co-mount. - */ - c = controller; - for (;;) { - _cleanup_free_ char *target = NULL, *tok = NULL; - - r = extract_first_word(&c, &tok, ",", 0); - if (r < 0) - return log_error_errno(r, "Failed to extract co-mounted cgroup controller: %m"); - if (r == 0) - break; - - if (streq(controller, tok)) - break; - - target = prefix_root("/sys/fs/cgroup/", tok); - if (!target) - return log_oom(); - - r = symlink_idempotent(controller, target); - if (r == -EINVAL) - return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); - if (r < 0) - return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); - } - } - -skip_controllers: - if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { - r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); - if (r < 0) - return r; - } - - r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); - if (r < 0) - return r; - - if (!userns) - return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL, - MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); - - return 0; -} - -/* Mount legacy cgroup hierarchy when cgroup namespaces are unsupported. */ -static int mount_legacy_cgns_unsupported( - const char *dest, - CGroupUnified unified_requested, - bool userns, - uid_t uid_shift, - uid_t uid_range, - const char *selinux_apifs_context) { - - _cleanup_set_free_free_ Set *controllers = NULL; - const char *cgroup_root; - int r; - - cgroup_root = prefix_roota(dest, "/sys/fs/cgroup"); - - (void) mkdir_p(cgroup_root, 0755); - - /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ - r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); - if (r < 0) - return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); - if (r == 0) { - _cleanup_free_ char *options = NULL; - - r = tmpfs_patch_options("mode=755", uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &options); - if (r < 0) - return log_oom(); - - r = mount_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", - MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); - if (r < 0) - return r; - } - - r = cg_all_unified(); - if (r < 0) - return r; - if (r > 0) - goto skip_controllers; - - r = cg_kernel_controllers(&controllers); - if (r < 0) - return log_error_errno(r, "Failed to determine cgroup controllers: %m"); - - for (;;) { - _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL; - - controller = set_steal_first(controllers); - if (!controller) - break; - - origin = prefix_root("/sys/fs/cgroup/", controller); - if (!origin) - return log_oom(); - - r = readlink_malloc(origin, &combined); - if (r == -EINVAL) { - /* Not a symbolic link, but directly a single cgroup hierarchy */ - - r = mount_legacy_cgroup_hierarchy(dest, controller, controller, true); - if (r < 0) - return r; - - } else if (r < 0) - return log_error_errno(r, "Failed to read link %s: %m", origin); - else { - _cleanup_free_ char *target = NULL; - - target = prefix_root(dest, origin); - if (!target) - return log_oom(); - - /* A symbolic link, a combination of controllers in one hierarchy */ - - if (!filename_is_valid(combined)) { - log_warning("Ignoring invalid combined hierarchy %s.", combined); - continue; - } - - r = mount_legacy_cgroup_hierarchy(dest, combined, combined, true); - if (r < 0) - return r; - - r = symlink_idempotent(combined, target); - if (r == -EINVAL) - return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); - if (r < 0) - return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); - } - } - -skip_controllers: - if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { - r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); - if (r < 0) - return r; - } - - r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); - if (r < 0) - return r; - - return mount_verbose(LOG_ERR, NULL, cgroup_root, NULL, - MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); -} - -static int mount_unified_cgroups(const char *dest) { - const char *p; - int r; - - assert(dest); - - p = prefix_roota(dest, "/sys/fs/cgroup"); - - (void) mkdir_p(p, 0755); - - r = path_is_mount_point(p, dest, AT_SYMLINK_FOLLOW); - if (r < 0) - return log_error_errno(r, "Failed to determine if %s is mounted already: %m", p); - if (r > 0) { - p = prefix_roota(dest, "/sys/fs/cgroup/cgroup.procs"); - if (access(p, F_OK) >= 0) - return 0; - if (errno != ENOENT) - return log_error_errno(errno, "Failed to determine if mount point %s contains the unified cgroup hierarchy: %m", p); - - log_error("%s is already mounted but not a unified cgroup hierarchy. Refusing.", p); - return -EINVAL; - } - - return mount_verbose(LOG_ERR, "cgroup", p, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); -} - -int mount_cgroups( - const char *dest, - CGroupUnified unified_requested, - bool userns, - uid_t uid_shift, - uid_t uid_range, - const char *selinux_apifs_context, - bool use_cgns) { - - if (unified_requested >= CGROUP_UNIFIED_ALL) - return mount_unified_cgroups(dest); - if (use_cgns) - return mount_legacy_cgns_supported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); - - return mount_legacy_cgns_unsupported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); -} - -static int mount_systemd_cgroup_writable_one(const char *root, const char *own) { - int r; - - assert(root); - assert(own); - - /* Make our own cgroup a (writable) bind mount */ - r = mount_verbose(LOG_ERR, own, own, NULL, MS_BIND, NULL); - if (r < 0) - return r; - - /* And then remount the systemd cgroup root read-only */ - return mount_verbose(LOG_ERR, NULL, root, NULL, - MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); -} - -int mount_systemd_cgroup_writable( - const char *dest, - CGroupUnified unified_requested) { - - _cleanup_free_ char *own_cgroup_path = NULL; - const char *root, *own; - int r; - - assert(dest); - - r = cg_pid_get_path(NULL, 0, &own_cgroup_path); - if (r < 0) - return log_error_errno(r, "Failed to determine our own cgroup path: %m"); - - /* If we are living in the top-level, then there's nothing to do... */ - if (path_equal(own_cgroup_path, "/")) - return 0; - - if (unified_requested >= CGROUP_UNIFIED_ALL) { - - root = prefix_roota(dest, "/sys/fs/cgroup"); - own = strjoina(root, own_cgroup_path); - - } else { - - if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { - root = prefix_roota(dest, "/sys/fs/cgroup/unified"); - own = strjoina(root, own_cgroup_path); - - r = mount_systemd_cgroup_writable_one(root, own); - if (r < 0) - return r; - } - - root = prefix_roota(dest, "/sys/fs/cgroup/systemd"); - own = strjoina(root, own_cgroup_path); - } - - return mount_systemd_cgroup_writable_one(root, own); -} - int setup_volatile_state( const char *directory, VolatileMode mode, diff --git a/src/nspawn/nspawn-mount.h b/src/nspawn/nspawn-mount.h index e948d02..db55759 100644 --- a/src/nspawn/nspawn-mount.h +++ b/src/nspawn/nspawn-mount.h @@ -46,9 +46,6 @@ int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_onl int mount_all(const char *dest, MountSettingsMask mount_settings, uid_t uid_shift, const char *selinux_apifs_context); int mount_sysfs(const char *dest, MountSettingsMask mount_settings); -int mount_cgroups(const char *dest, CGroupUnified unified_requested, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, bool use_cgns); -int mount_systemd_cgroup_writable(const char *dest, CGroupUnified unified_requested); - int mount_custom(const char *dest, CustomMount *mounts, size_t n, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context); int setup_volatile(const char *directory, VolatileMode mode, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context); @@ -56,3 +53,5 @@ int setup_volatile_state(const char *directory, VolatileMode mode, bool userns, int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s); int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old); + +int tmpfs_patch_options(const char *options,uid_t uid_shift, const char *selinux_apifs_context, char **ret); -- 2.7.4