int path_is_mount_point(const char *t, bool allow_symlink) {
- union file_handle_union h = {
- .handle.handle_bytes = MAX_HANDLE_SZ
- };
-
- int mount_id, mount_id_parent;
+ union file_handle_union h = FILE_HANDLE_INIT;
+ int mount_id = -1, mount_id_parent = -1;
_cleanup_free_ char *parent = NULL;
struct stat a, b;
int r;
+ bool nosupp = false;
/* We are not actually interested in the file handles, but
* name_to_handle_at() also passes us the mount ID, hence use
r = name_to_handle_at(AT_FDCWD, t, &h.handle, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0);
if (r < 0) {
- if (IN_SET(errno, ENOSYS, EOPNOTSUPP))
+ if (errno == ENOSYS)
+ /* This kernel does not support name_to_handle_at()
+ * fall back to the traditional stat() logic. */
+ goto fallback;
+ else if (errno == EOPNOTSUPP)
/* This kernel or file system does not support
* name_to_handle_at(), hence fallback to the
* traditional stat() logic */
- goto fallback;
-
- if (errno == ENOENT)
+ nosupp = true;
+ else if (errno == ENOENT)
return 0;
-
- return -errno;
+ else
+ return -errno;
}
r = path_get_parent(t, &parent);
return r;
h.handle.handle_bytes = MAX_HANDLE_SZ;
- r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0);
- 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 */
+ r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, AT_SYMLINK_FOLLOW);
+ if (r < 0)
if (errno == EOPNOTSUPP)
- return 1;
-
- return -errno;
- }
-
- return mount_id != mount_id_parent;
+ if (nosupp)
+ /* Neither parent nor child do name_to_handle_at()?
+ We have no choice but to fall back. */
+ goto fallback;
+ else
+ /* The parent can't do name_to_handle_at() but
+ * the directory we are interested in can?
+ * Or the other way around?
+ * If so, it must be a mount point. */
+ return 1;
+ else
+ return -errno;
+ else
+ return mount_id != mount_id_parent;
fallback:
if (allow_symlink)
return -errno;
}
+ free(parent);
+ parent = NULL;
+
r = path_get_parent(t, &parent);
if (r < 0)
return r;