static int clean_posix_shm_internal(DIR *dir, uid_t uid) {
struct dirent *de;
int ret = 0, r;
assert(dir);
FOREACH_DIRENT(de, dir, goto fail) {
struct stat st;
if (STR_IN_SET(de->d_name, "..", "."))
continue;
if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
if (errno == ENOENT)
continue;
log_warning("Failed to stat() POSIX shared memory segment %s: %m", de->d_name);
ret = -errno;
continue;
}
if (st.st_uid != uid)
continue;
if (S_ISDIR(st.st_mode)) {
_cleanup_closedir_ DIR *kid;
kid = xopendirat(dirfd(dir), de->d_name, O_NOFOLLOW|O_NOATIME);
if (!kid) {
if (errno != ENOENT) {
log_warning("Failed to enter shared memory directory %s: %m", de->d_name);
ret = -errno;
}
} else {
r = clean_posix_shm_internal(kid, uid);
if (r < 0)
ret = r;
}
if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) {
if (errno == ENOENT)
continue;
log_warning("Failed to remove POSIX shared memory directory %s: %m", de->d_name);
ret = -errno;
}
} else {
if (unlinkat(dirfd(dir), de->d_name, 0) < 0) {
if (errno == ENOENT)
continue;
log_warning("Failed to remove POSIX shared memory segment %s: %m", de->d_name);
ret = -errno;
}
}
}
return ret;
fail:
log_warning("Failed to read /dev/shm: %m");
return -errno;
}
static int dir_cleanup(
const char *p,
DIR *d,
const struct stat *ds,
usec_t cutoff,
dev_t rootdev,
bool mountpoint,
int maxdepth,
bool keep_this_level)
{
struct dirent *dent;
struct timespec times[2];
bool deleted = false;
char *sub_path = NULL;
int r = 0;
while ((dent = readdir(d))) {
struct stat s;
usec_t age;
if (streq(dent->d_name, ".") ||
streq(dent->d_name, ".."))
continue;
if (fstatat(dirfd(d), dent->d_name, &s, AT_SYMLINK_NOFOLLOW) < 0) {
if (errno != ENOENT) {
log_error("stat(%s/%s) failed: %m", p, dent->d_name);
r = -errno;
}
continue;
}
/* Stay on the same filesystem */
if (s.st_dev != rootdev)
continue;
/* Do not delete read-only files owned by root */
if (s.st_uid == 0 && !(s.st_mode & S_IWUSR))
continue;
free(sub_path);
sub_path = NULL;
if (asprintf(&sub_path, "%s/%s", p, dent->d_name) < 0) {
log_error("Out of memory");
r = -ENOMEM;
goto finish;
}
/* Is there an item configured for this path? */
if (hashmap_get(items, sub_path))
continue;
if (find_glob(globs, sub_path))
continue;
if (S_ISDIR(s.st_mode)) {
if (mountpoint &&
streq(dent->d_name, "lost+found") &&
s.st_uid == 0)
continue;
if (maxdepth <= 0)
log_warning("Reached max depth on %s.", sub_path);
else {
DIR *sub_dir;
int q;
sub_dir = xopendirat(dirfd(d), dent->d_name, O_NOFOLLOW|O_NOATIME);
if (sub_dir == NULL) {
if (errno != ENOENT) {
log_error("opendir(%s/%s) failed: %m", p, dent->d_name);
r = -errno;
}
continue;
}
q = dir_cleanup(sub_path, sub_dir, &s, cutoff, rootdev, false, maxdepth-1, false);
closedir(sub_dir);
if (q < 0)
r = q;
}
/* Note: if you are wondering why we don't
* support the sticky bit for excluding
* directories from cleaning like we do it for
* other file system objects: well, the sticky
* bit already has a meaning for directories,
* so we don't want to overload that. */
if (keep_this_level)
continue;
/* Ignore ctime, we change it when deleting */
age = MAX(timespec_load(&s.st_mtim),
timespec_load(&s.st_atim));
if (age >= cutoff)
continue;
log_debug("rmdir '%s'\n", sub_path);
if (unlinkat(dirfd(d), dent->d_name, AT_REMOVEDIR) < 0) {
if (errno != ENOENT && errno != ENOTEMPTY) {
log_error("rmdir(%s): %m", sub_path);
r = -errno;
}
}
} else {
/* Skip files for which the sticky bit is
* set. These are semantics we define, and are
* unknown elsewhere. See XDG_RUNTIME_DIR
* specification for details. */
if (s.st_mode & S_ISVTX)
continue;
if (mountpoint && S_ISREG(s.st_mode)) {
if (streq(dent->d_name, ".journal") &&
s.st_uid == 0)
continue;
if (streq(dent->d_name, "aquota.user") ||
streq(dent->d_name, "aquota.group"))
continue;
}
/* Ignore sockets that are listed in /proc/net/unix */
if (S_ISSOCK(s.st_mode) && unix_socket_alive(sub_path))
continue;
/* Ignore device nodes */
if (S_ISCHR(s.st_mode) || S_ISBLK(s.st_mode))
continue;
/* Keep files on this level around if this is
* requested */
if (keep_this_level)
continue;
age = MAX3(timespec_load(&s.st_mtim),
timespec_load(&s.st_atim),
timespec_load(&s.st_ctim));
if (age >= cutoff)
continue;
log_debug("unlink '%s'\n", sub_path);
if (unlinkat(dirfd(d), dent->d_name, 0) < 0) {
if (errno != ENOENT) {
log_error("unlink(%s): %m", sub_path);
r = -errno;
}
}
deleted = true;
}
}
finish:
if (deleted) {
/* Restore original directory timestamps */
times[0] = ds->st_atim;
times[1] = ds->st_mtim;
if (futimens(dirfd(d), times) < 0)
log_error("utimensat(%s): %m", p);
}
free(sub_path);
return r;
}