#include "log.h"
#include "strv.h"
#include "path-util.h"
+#include "missing.h"
bool path_is_absolute(const char *p) {
return p[0] == '/';
}
int path_is_mount_point(const char *t, bool allow_symlink) {
- struct stat a, b;
char *parent;
int r;
+ struct file_handle *h;
+ int mount_id, mount_id_parent;
+ struct stat a, b;
- if (allow_symlink)
- r = stat(t, &a);
- else
- r = lstat(t, &a);
+ /* We are not actually interested in the file handles, but
+ * name_to_handle_at() also passes us the mount ID, hence use
+ * it but throw the handle away */
+
+ if (path_equal(t, "/"))
+ return 1;
+
+ h = alloca(MAX_HANDLE_SZ);
+ h->handle_bytes = MAX_HANDLE_SZ;
+ r = name_to_handle_at(AT_FDCWD, t, h, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0);
if (r < 0) {
+ if (errno == ENOTSUP)
+ /* This file system does not support
+ * name_to_handle_at(), hence fallback to the
+ * traditional stat() logic */
+ goto fallback;
+
if (errno == ENOENT)
return 0;
return -errno;
}
+ r = path_get_parent(t, &parent);
+ if (r < 0)
+ return r;
+
+ h->handle_bytes = MAX_HANDLE_SZ;
+ r = name_to_handle_at(AT_FDCWD, parent, h, &mount_id_parent, 0);
+ free(parent);
+
+ if (r < 0) {
+ /* The parent can't do name_to_handle_at() but the
+ * directory we are interested in can? If so, it must
+ * be a mount point */
+ if (errno == ENOTSUP)
+ return 1;
+
+ return -errno;
+ }
+
+ return mount_id != mount_id_parent;
+
+fallback:
+ if (allow_symlink)
+ r = stat(t, &a);
+ else
+ r = lstat(t, &a);
+
+ if (r < 0)
+ return -errno;
+
r = path_get_parent(t, &parent);
if (r < 0)
return r;