@@ -188,6 +188,7 @@ tests := \
tst-closefrom \
tst-copy_file_range \
tst-faccessat \
+ tst-fchmod-fuse \
tst-fchmodat \
tst-fchownat \
tst-fcntl \
new file mode 100644
@@ -0,0 +1,117 @@
+/* FUSE-based test for fchmod.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/fuse.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+
+/* Set from do_test to indicate the expected incoming mode change request. */
+static _Atomic int expected_mode;
+
+static void
+fuse_thread (struct support_fuse *f, void *closure)
+{
+ struct fuse_in_header *inh;
+ while ((inh = support_fuse_read (f)) != NULL)
+ {
+ if (support_fuse_handle_mountpoint (f)
+ || (inh->nodeid == 1 && support_fuse_handle_directory (f)))
+ continue;
+ switch (inh->opcode)
+ {
+ case FUSE_LOOKUP:
+ {
+ char *name = support_fuse_cast (LOOKUP, inh);
+ TEST_COMPARE_STRING (name, "file");
+ struct fuse_entry_out *out
+ = support_fuse_prepare_entry (f, 2);
+ out->attr.mode = S_IFREG | 0600;
+ support_fuse_reply_prepared (f);
+ }
+ break;
+ case FUSE_OPEN:
+ {
+ TEST_COMPARE (inh->nodeid, 2);
+ struct fuse_open_in *p = support_fuse_cast (OPEN, inh);
+ TEST_COMPARE (p->flags & O_ACCMODE, O_RDWR);
+ struct fuse_open_out out = { 0, };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ break;
+ case FUSE_SETATTR:
+ {
+ TEST_COMPARE (inh->nodeid, 2);
+ struct fuse_setattr_in *p = support_fuse_cast (SETATTR, inh);
+ TEST_COMPARE (p->valid , FATTR_MODE);
+ TEST_COMPARE (p->mode, S_IFREG | expected_mode);
+ struct fuse_attr_out *out = support_fuse_prepare_attr (f);
+ out->attr.mode = S_IFREG | p->mode;
+ support_fuse_reply_prepared (f);
+ }
+ break;
+ case FUSE_FLUSH:
+ support_fuse_reply_empty (f);
+ break;
+ default:
+ support_fuse_reply_error (f, EIO);
+ }
+ }
+}
+
+/* Test all mode values with the specified extra bits. */
+static void
+test_with_bits (int fd, unsigned int extra_bits)
+{
+ for (int do_mode = 0; do_mode <= 07777; ++do_mode)
+ {
+ expected_mode = do_mode;
+ TEST_COMPARE (fchmod (fd, extra_bits | do_mode), 0);
+ }
+}
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ if (!support_enter_mount_namespace ())
+ FAIL_UNSUPPORTED ("mount namespaces not supported");
+
+ struct support_fuse *f = support_fuse_mount (fuse_thread, NULL);
+ char *path = xasprintf ("%s/file", support_fuse_mountpoint (f));
+ int fd = xopen (path, O_RDWR, 0600);
+ free (path);
+
+ test_with_bits (fd, 0);
+ /* POSIX requires that the extra bits are ignored. */
+ test_with_bits (fd, S_IFREG);
+ test_with_bits (fd, S_IFDIR);
+ test_with_bits (fd, ~07777);
+
+ xclose (fd);
+ support_fuse_unmount (f);
+
+ return 0;
+}
+
+#include <support/test-driver.c>