[PATCH] Linux: Add test case for bug 33245
H.J. Lu
hjl.tools@gmail.com
Sat Aug 2 13:33:41 GMT 2025
On Sat, Aug 2, 2025 at 4:43 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> The copy_file_range system call seems the only one that can return
> an off64_t value. Use FUSE to exercise this, without actually
lseek is another one.
> 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
>
--
H.J.
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