From 1108b2858019c82f165fffa7eb19826d4f5a1b79 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Sat, 20 May 2017 17:49:22 -0400 Subject: nspawn: Improve error messages --- src/nspawn/nspawn-cgroup.c | 44 ++++++++++++++++++++++++++++---------------- src/nspawn/nspawn.c | 4 ++-- 2 files changed, 30 insertions(+), 18 deletions(-) diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c index df0044990a..b64475bcb4 100644 --- a/src/nspawn/nspawn-cgroup.c +++ b/src/nspawn/nspawn-cgroup.c @@ -65,11 +65,11 @@ static int chown_cgroup(pid_t pid, uid_t uid_shift) { r = cg_pid_get_path(NULL, pid, &path); if (r < 0) - return log_error_errno(r, "Failed to get container cgroup path: %m"); + return log_error_errno(r, "Failed to get host cgroup of the container: %m"); r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs); if (r < 0) - return log_error_errno(r, "Failed to get file system path for container cgroup: %m"); + return log_error_errno(r, "Failed to get host file system path for container cgroup: %m"); r = chown_cgroup_path(fs, uid_shift); if (r < 0) @@ -82,12 +82,14 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner _cleanup_free_ char *cgroup = NULL; char mountpoint[] = "/tmp/containerXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1]; bool undo_mount = false; - const char *fn; + const char *fn, *inner_hier; int r; +#define LOG_PFIX "PID " PID_FMT ": sync host cgroup -> container cgroup" + unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER); if (unified < 0) - return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m"); + return log_error_errno(unified, LOG_PFIX ": failed to determine host cgroup version: %m", pid); if ((outer_cgver >= CGROUP_UNIFIED_SYSTEMD) == (inner_cgver >= CGROUP_UNIFIED_SYSTEMD)) return 0; @@ -99,20 +101,27 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup); if (r < 0) - return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid); + return log_error_errno(r, LOG_PFIX ": failed to determine host cgroup: %m", pid); /* In order to access the container's hierarchy we need to mount it */ if (!mkdtemp(mountpoint)) - return log_error_errno(errno, "Failed to generate temporary mount point for container hierarchy: %m"); + return log_error_errno(errno, LOG_PFIX ": failed to create temporary mount point for container cgroup hierarchy: %m", pid); if (outer_cgver >= CGROUP_UNIFIED_SYSTEMD) { + /* host: v2 ; container: v1 */ + inner_hier = "?:name=systemd"; r = mount_verbose(LOG_ERR, "cgroup", mountpoint, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr"); - else + } else { + /* host: v1 ; container: v2 */ + inner_hier = "0:"; r = mount_verbose(LOG_ERR, "cgroup", mountpoint, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); - if (r < 0) + } + if (r < 0) { + log_error(LOG_PFIX ": failed to mount container cgroup hierarchy", pid); goto finish; + } undo_mount = true; @@ -128,17 +137,20 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner sprintf(pid_string, PID_FMT, pid); r = write_string_file(fn, pid_string, 0); if (r < 0) { - log_error_errno(r, "Failed to move process: %m"); + log_error_errno(r, LOG_PFIX ": failed to move process to `%s:%s': %m", pid, inner_hier, cgroup); goto finish; } fn = strjoina(mountpoint, cgroup); r = chown_cgroup_path(fn, uid_shift); if (r < 0) - log_error_errno(r, "Failed to chown() cgroup %s: %m", fn); + log_error_errno(r, LOG_PFIX ": chown(path=\"%s\", uid=" UID_FMT "): %m", pid, fn, uid_shift); finish: - if (undo_mount) - (void) umount_verbose(mountpoint); + if (undo_mount) { + r = umount_verbose(mountpoint); + if (r < 0) + log_error_errno(r, LOG_PFIX ": umount(\"%s\"): %m", pid, mountpoint); + } (void) rmdir(mountpoint); return r; @@ -161,21 +173,21 @@ static int create_subcgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified r = cg_mask_supported(&supported); if (r < 0) - return log_error_errno(r, "Failed to determine supported controllers: %m"); + return log_error_errno(r, "Failed to create host subcgroup: Failed to determine supported controllers: %m"); r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); if (r < 0) - return log_error_errno(r, "Failed to get our control group: %m"); + return log_error_errno(r, "Failed to create host subcgroup: Failed to get our control group: %m"); child = strjoina(cgroup, "/payload"); r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid); if (r < 0) - return log_error_errno(r, "Failed to create %s subcgroup: %m", child); + return log_error_errno(r, "Failed to create host subcgroup: Failed to create %s subcgroup: %m", child); child = strjoina(cgroup, "/supervisor"); r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0); if (r < 0) - return log_error_errno(r, "Failed to create %s subcgroup: %m", child); + return log_error_errno(r, "Failed to create host subcgroup: Failed to create %s subcgroup: %m", child); /* Try to enable as many controllers as possible for the new payload. */ (void) cg_enable_everywhere(supported, supported, cgroup); diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index d3ef37fba3..33863b01b3 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -339,7 +339,7 @@ static int pick_cgroup_version(const char *directory, CGroupUnified outer) { * false negative here for 230. */ r = systemd_installation_has_version(directory, 230); if (r < 0) - return log_error_errno(r, "Failed to determine systemd version in container: %m"); + return log_error_errno(r, "Failed to decide cgroup version to use: Failed to determine systemd version in container: %m"); if (r > 0) arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL; else @@ -349,7 +349,7 @@ static int pick_cgroup_version(const char *directory, CGroupUnified outer) { /* Mixed cgroup hierarchy support was added in 232 */ r = systemd_installation_has_version(directory, 232); if (r < 0) - return log_error_errno(r, "Failed to determine systemd version in container: %m"); + return log_error_errno(r, "Failed to decide cgroup version to use: Failed to determine systemd version in container: %m"); if (r > 0) arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD; else -- cgit v1.2.3-54-g00ecf