From b9a2add4c257e40e60e49eb4edaf7925ba569c78 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 8 Dec 2016 17:19:27 +0100 Subject: [PATCH 1/1] util-lib: beef path_is_os_tree() up a bit Let's use chase_symlinks() when looking for /etc/os-release and /usr/lib/os-release as these files might be symlinks (and actually are IRL on some distros). --- src/basic/stat-util.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c index 81c13ec59..2a6e89b75 100644 --- a/src/basic/stat-util.c +++ b/src/basic/stat-util.c @@ -150,22 +150,29 @@ int path_is_read_only_fs(const char *path) { #if 0 /// UNNEEDED by elogind int path_is_os_tree(const char *path) { - char *p; int r; assert(path); - /* We use /usr/lib/os-release as flag file if something is an OS */ - p = strjoina(path, "/usr/lib/os-release"); - r = access(p, F_OK); - if (r >= 0) - return 1; + /* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir + * always results in -ENOENT, and we can properly distuingish the case where the whole root doesn't exist from + * the case where just the os-release file is missing. */ + if (laccess(path, F_OK) < 0) + return -errno; - /* Also check for the old location in /etc, just in case. */ - p = strjoina(path, "/etc/os-release"); - r = access(p, F_OK); + /* We use /usr/lib/os-release as flag file if something is an OS */ + r = chase_symlinks("/usr/lib/os-release", path, CHASE_PREFIX_ROOT, NULL); + if (r == -ENOENT) { + + /* Also check for the old location in /etc, just in case. */ + r = chase_symlinks("/etc/os-release", path, CHASE_PREFIX_ROOT, NULL); + if (r == -ENOENT) + return 0; /* We got nothing */ + } + if (r < 0) + return r; - return r >= 0; + return 1; } #endif // 0 -- 2.30.2