[PATCH] Linux: Add test case for bug 33245
Florian Weimer
fweimer@redhat.com
Sat Aug 2 11:42:18 GMT 2025
The copy_file_range system call seems the only one that can return
an off64_t value. Use FUSE to exercise this, without actually
creating such large files or copying any data. Due to FUSE protocol
limitations, only sizes up to UINT_MAX can be tested, but this is
sufficient to check for the presence of bug 33245.
---
sysdeps/unix/sysv/linux/Makefile | 1 +
.../unix/sysv/linux/tst-copy_file_range-large.c | 234 +++++++++++++++++++++
2 files changed, 235 insertions(+)
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index c47cbdf428..2c5bf42236 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -192,6 +192,7 @@ tests += \
tst-clone \
tst-clone2 \
tst-clone3 \
+ tst-copy_file_range-large \
tst-epoll \
tst-epoll-ioctls \
tst-fanotify \
diff --git a/sysdeps/unix/sysv/linux/tst-copy_file_range-large.c b/sysdeps/unix/sysv/linux/tst-copy_file_range-large.c
new file mode 100644
index 0000000000..4a87f1db85
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-copy_file_range-large.c
@@ -0,0 +1,234 @@
+/* Test for copy_file_range with large sizes (bug 33245).
+ Copyright (C) 2025 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/>. */
+
+/* This test exercises copy_file_range with various large file sizes
+ on FUSE filesystems to verify proper handling of system call return
+ values. No data is actually copied. */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/fuse.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static void
+fuse_thread (struct support_fuse *f, void *closure)
+{
+ /* Node IDs for our test files. */
+ enum { NODE_SOURCE = 2, NODE_DEST = 3 };
+ /* A large size, so that the kernel does not fail the
+ copy_file_range attempt before performing the FUSE callback.
+ Only the source file size matters to the kernel, but both files
+ use the same size for simplicity. */
+ const uint64_t file_size = 1LLU << 61;
+
+ struct fuse_in_header *inh;
+ while ((inh = support_fuse_next (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);
+ int node = 0;
+ if (inh->nodeid == 1 && strcmp (name, "source") == 0)
+ node = NODE_SOURCE;
+ else if (inh->nodeid == 1 && strcmp (name, "dest") == 0)
+ node = NODE_DEST;
+
+ if (node != 0)
+ {
+ struct fuse_entry_out *out
+ = support_fuse_prepare_entry (f, node);
+ out->attr.mode = S_IFREG | 0600;
+ out->attr.size = file_size;
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ }
+ break;
+
+ case FUSE_OPEN:
+ /* File open */
+ {
+ if (inh->nodeid == NODE_SOURCE || inh->nodeid == NODE_DEST)
+ {
+ struct fuse_open_out out = { .fh = inh->nodeid };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ }
+ break;
+
+ case FUSE_GETATTR:
+ /* Get file attributes */
+ if (inh->nodeid == NODE_SOURCE || inh->nodeid == NODE_DEST)
+ {
+ struct fuse_attr_out *out = support_fuse_prepare_attr (f);
+ out->attr.mode = S_IFREG | 0600;
+ out->attr.size = file_size;
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ break;
+
+ case FUSE_COPY_FILE_RANGE:
+ {
+ struct fuse_copy_file_range_in *p
+ = support_fuse_cast (COPY_FILE_RANGE, inh);
+
+ /* Verify this is a copy from source to dest, starting at
+ offset 0. */
+ TEST_COMPARE (p->fh_in, NODE_SOURCE);
+ TEST_COMPARE (p->nodeid_out, NODE_DEST);
+ TEST_COMPARE (p->off_in, 0);
+ TEST_COMPARE (p->off_out, 0);
+ TEST_VERIFY (p->len > 0);
+ TEST_VERIFY (p->len <= file_size);
+
+ /* Pretend the copy succeeded. */
+ struct fuse_write_out out = { .size = p->len };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ break;
+
+ case FUSE_FLUSH:
+ support_fuse_reply_empty (f);
+ break;
+
+ default:
+ support_fuse_reply_error (f, EIO);
+ }
+ }
+}
+
+static void
+test_size (struct support_fuse *f, off64_t size)
+{
+ if (size != (ssize_t) size)
+ {
+ verbose_printf ("info: size 0x%llx is too large for ssize_t\n",
+ (unsigned long long int) size);
+ return;
+ }
+
+ verbose_printf ("info: testing copy size 0x%llx\n",
+ (unsigned long long int) size);
+
+ const char *mountpoint = support_fuse_mountpoint (f);
+ char *source_path = xasprintf ("%s/source", mountpoint);
+ char *dest_path = xasprintf ("%s/dest", mountpoint);
+
+ int source_fd = xopen (source_path, O_RDONLY, 0);
+ int dest_fd = xopen (dest_path, O_WRONLY, 0);
+
+ ssize_t copied = copy_file_range (source_fd, NULL, dest_fd, NULL, size, 0);
+ /* Avoid FAIL_UNSUPPORTED if it is likely bogus due to previous
+ copy_file_range successes. */
+ if (copied == -1 && errno == ENOSYS)
+ {
+ /* Unmounting avoids a test hang on exit. */
+ xclose (dest_fd);
+ xclose (source_fd);
+ support_fuse_unmount (f);
+ FAIL_UNSUPPORTED ("copy_file_range not supported");
+ }
+
+ TEST_COMPARE (copied, size);
+
+ xclose (dest_fd);
+ xclose (source_fd);
+ free (dest_path);
+ free (source_path);
+}
+
+static void
+test_all_sizes (struct support_fuse *f)
+{
+ test_size (f, 0); /* Not actually handled by the callback. */
+ test_size (f, 20);
+ test_size (f, 1 << 30);
+ test_size (f, INT_MAX);
+ for (int i = 0; i <= 5; ++i)
+ test_size (f, (1U << 31) + i);
+ for (int i = -4100; i <= -4090; ++i)
+ test_size (f, UINT_MAX + i);
+ for (int i = -100; i <= 0; ++i)
+ test_size (f, UINT_MAX + i);
+
+ /* We would like to test larger values than UINT_MAX here, but they
+ do not work because the FUSE protocol uses uint32_t for the
+ copy_file_range result in struct fuse_write_out. */
+}
+
+static void *
+test_cancel_state_variants (void *f_ptr)
+{
+ struct support_fuse *f = (struct support_fuse *) f_ptr;
+
+ verbose_printf ("info: testing default cancellation settings\n");
+ test_all_sizes (f);
+
+ verbose_printf ("info: testing with cancellation disabled\n");
+ TEST_COMPARE (pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL), 0);
+ test_all_sizes (f);
+
+ verbose_printf ("info: testing with cancellation disabled\n");
+ TEST_COMPARE (pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL), 0);
+ test_all_sizes (f);
+
+ return NULL;
+}
+
+static int
+do_test (void)
+{
+ support_fuse_init ();
+ struct support_fuse *f = support_fuse_mount (fuse_thread, NULL);
+
+ verbose_printf ("info: testing on main thread\n");
+ test_cancel_state_variants (f);
+
+ verbose_printf ("info: testing on secondary thread\n");
+ TEST_VERIFY (xpthread_join (xpthread_create
+ (NULL, test_cancel_state_variants, f))
+ == NULL);
+
+ verbose_printf ("info: testing on separate thread\n");
+
+ support_fuse_unmount (f);
+ return 0;
+}
+
+#include <support/test-driver.c>
base-commit: b02d910dd968a29c6ab2665b52be293d09899b6e
More information about the Libc-alpha
mailing list