+2018-08-21 Florian Weimer <fweimer@redhat.com>
+
+ * support/support.h (support_descriptor_supports_holes): Declare.
+ * support/Makefile (libsupport-routines): Add
+ support_descriptor_supports_holes.
+ * support/support_descriptor_supports_holes.c: New file.
+ * io/tst-copy_file_range.c: Call support_descriptor_supports_holes
+ and stop testing if holes are not supported.
+ * io/test-lfs.c (do_prepare): Likewise.
+ * sysdeps/unix/sysv/linux/tst-fallocate-common.c (do_prepare):
+ Likewise.
+ * timezone/tst-tzset.c (create_tz_file): Likewise.
+ * misc/tst-preadvwritev-common.c (temp_fd_supports_holes) New
+ variable.
+ (do_prepare): Set it.
+ * misc/tst-preadvwritev64.c (do_test): Use temp_fd_supports_holes.
+
2018-08-21 Florian Weimer <fweimer@redhat.com>
[BZ #17248]
#include <error.h>
#include <errno.h>
#include <sys/resource.h>
+#include <support/check.h>
/* Prototype for our test function. */
extern void do_prepare (int argc, char *argv[]);
else
error (EXIT_FAILURE, errno, "cannot create temporary file");
}
+ if (!support_descriptor_supports_holes (fd))
+ FAIL_UNSUPPORTED ("File %s does not support holes", name);
add_temp_file (name);
if (getrlimit64 (RLIMIT_FSIZE, &rlim) != 0)
*p = rand () >> 24;
infd = create_temp_file ("tst-copy_file_range-in-", &infile);
- xclose (create_temp_file ("tst-copy_file_range-out-", &outfile));
+ {
+ int outfd = create_temp_file ("tst-copy_file_range-out-", &outfile);
+ if (!support_descriptor_supports_holes (outfd))
+ FAIL_UNSUPPORTED ("File %s does not support holes", outfile);
+ xclose (outfd);
+ }
/* Try to find a different directory from the default input/output
file. */
<http://www.gnu.org/licenses/>. */
#include <array_length.h>
+#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <errno.h>
#include <support/check.h>
#include <support/temp_file.h>
+#include <support/support.h>
#include <support/xunistd.h>
static char *temp_filename;
static int temp_fd;
+static bool temp_fd_supports_holes;
static int do_test (void);
temp_fd = create_temp_file ("tst-preadvwritev.", &temp_filename);
if (temp_fd == -1)
FAIL_EXIT1 ("cannot create temporary file");
+ temp_fd_supports_holes = support_descriptor_supports_holes (temp_fd);
}
#define PREPARE do_prepare
ret = do_test_with_offset (0);
+ if (!temp_fd_supports_holes)
+ {
+ puts ("warning: partial test due to lack of support for holes");
+ return ret;
+ }
+
/* Create a sparse file larger than 4GB to check if offset is handled
correctly in p{write,read}v64. */
off_t base_offset = UINT32_MAX + 2048LL;
support_capture_subprocess \
support_capture_subprocess_check \
support_chroot \
+ support_descriptor_supports_holes \
support_enter_mount_namespace \
support_enter_network_namespace \
support_format_address_family \
the result). */
char *support_quote_blob (const void *blob, size_t length);
+/* Returns non-zero if the file descriptor is a regular file on a file
+ system which supports holes (that is, seeking and writing does not
+ allocate storage for the range of zeros). FD must refer to a
+ regular file open for writing, and initially empty. */
+int support_descriptor_supports_holes (int fd);
+
/* Error-checking wrapper functions which terminate the process on
error. */
--- /dev/null
+/* Test for file system hole support.
+ Copyright (C) 2018 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdbool.h>
+#include <support.h>
+#include <support/check.h>
+#include <sys/stat.h>
+#include <xunistd.h>
+
+int
+support_descriptor_supports_holes (int fd)
+{
+ enum
+ {
+ /* Write offset for the enlarged file. This value is arbitrary
+ and hopefully large enough to trigger the creation of holes.
+ We cannot use the file system block size as a reference here
+ because it is incorrect for network file systems. */
+ write_offset = 16 * 1024 * 1024,
+
+ /* Our write may add this number of additional blocks (see
+ block_limit below). */
+ block_headroom = 8,
+ };
+
+ struct stat64 st;
+ xfstat (fd, &st);
+ if (!S_ISREG (st.st_mode))
+ FAIL_EXIT1 ("descriptor %d does not refer to a regular file", fd);
+ if (st.st_size != 0)
+ FAIL_EXIT1 ("descriptor %d does not refer to an empty file", fd);
+ if (st.st_blocks > block_headroom)
+ FAIL_EXIT1 ("descriptor %d refers to a pre-allocated file (%lld blocks)",
+ fd, (long long int) st.st_blocks);
+
+ /* Write a single byte at the start of the file to compute the block
+ usage for a single byte. */
+ xlseek (fd, 0, SEEK_SET);
+ char b = '@';
+ xwrite (fd, &b, 1);
+ /* Attempt to bypass delayed allocation. */
+ TEST_COMPARE (fsync (fd), 0);
+ xfstat (fd, &st);
+
+ /* This limit is arbitrary. The file system needs to store
+ somewhere that data exists at the write offset, and this may
+ moderately increase the number of blocks used by the file, in
+ proportion to the initial block count, but not in proportion to
+ the write offset. */
+ unsigned long long int block_limit = 2 * st.st_blocks + block_headroom;
+
+ /* Write a single byte at 16 megabytes. */
+ xlseek (fd, write_offset, SEEK_SET);
+ xwrite (fd, &b, 1);
+ /* Attempt to bypass delayed allocation. */
+ TEST_COMPARE (fsync (fd), 0);
+ xfstat (fd, &st);
+ bool supports_holes = st.st_blocks <= block_limit;
+
+ /* Also check that extending the file does not fill up holes. */
+ xftruncate (fd, 2 * write_offset);
+ /* Attempt to bypass delayed allocation. */
+ TEST_COMPARE (fsync (fd), 0);
+ xfstat (fd, &st);
+ supports_holes = supports_holes && st.st_blocks <= block_limit;
+
+ /* Return to a zero-length file. */
+ xftruncate (fd, 0);
+ xlseek (fd, 0, SEEK_SET);
+
+ return supports_holes;
+}
temp_fd = create_temp_file ("tst-fallocate.", &temp_filename);
if (temp_fd == -1)
FAIL_EXIT1 ("cannot create temporary file: %m");
+ if (!support_descriptor_supports_holes (temp_fd))
+ FAIL_UNSUPPORTED ("File %s does not support holes", temp_filename);
}
#define PREPARE do_prepare
#include <sys/resource.h>
#include <time.h>
#include <unistd.h>
+#include <support/check.h>
#define TIMEOUT 5
static int do_test (void);
int fd = create_temp_file ("tst-tzset-", &path);
if (fd < 0)
exit (1);
+ if (!support_descriptor_supports_holes (fd))
+ FAIL_UNSUPPORTED ("File %s does not support holes", path);
// Reopen for large-file support.
close (fd);
projects / thirdparty / glibc.git / commitdiff
