b684326e69
Based on patch by Pavel Raiskup. Use SEEK_HOLE/SEEK_DATA feature of lseek on systems that support it. This can make archiving of sparse files much faster. Implement the --hole-detection option to allow users to select hole-detection method. * src/common.h (hole_detection_method): New enum. (hole_detection): New global. * src/sparse.c (sparse_scan_file_wholesparse): New function as a method for detecting sparse files without any data. (sparse_scan_file_raw): Rename from sparse_scan_file; with edits. (sparse_scan_file_seek): New function. (sparse_scan_file): Reimplement function. * src/tar.c: New option --hole-detection * tests/checkseekhole.c: New file. * tests/.gitignore: Mention two test binaries. * tests/Makefile.am: Add new tests. * tests/testsuite.at (AT_SEEKHOLE_PREREQ): New macro. Include sparse06.at. * tests/sparse06.at: New test case. * tests/sparse02.at: Force raw hole-detection method. * tests/sparsemv.at: Likewise. * tests/sparsemvp.at: Likewise. * doc/tar.1: Document --hole-detection option. * doc/tar.texi: Document hole-detection algorithms and command-line options. * NEWS: Document hole-detection.
93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
/* Test suite for GNU tar - SEEK_HOLE detector.
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Copyright 2015 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any later
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version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program. If not, see <http://www.gnu.org/licenses/>.
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Description: detect whether it is possible to work with SEEK_HOLE on
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particular operating system and file system. */
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#include "config.h"
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <fcntl.h>
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enum {
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EX_OK = 0, /* SEEK_HOLE support */
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EX_FAIL, /* test failed - no SEEK_HOLE support */
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EX_BAD, /* test is not relevant */
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};
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int
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check_seek_hole (int fd)
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{
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#ifdef SEEK_HOLE
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struct stat stat;
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off_t offset;
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/* hole of 100MB */
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if (lseek (fd, 100*1024*1024, SEEK_END) < 0)
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return EX_BAD;
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/* piece of data */
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if (write (fd, "data\n", 5) != 5)
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return EX_BAD;
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/* another hole */
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if (lseek (fd, 100*1024*1024, SEEK_END) < 0)
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return EX_BAD;
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/* piece of data */
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if (write (fd, "data\n", 5) != 5)
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return EX_BAD;
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if (fstat (fd, &stat))
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return EX_BAD;
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offset = lseek (fd, 0, SEEK_DATA);
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if (offset == (off_t)-1)
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return EX_FAIL;
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offset = lseek (fd, offset, SEEK_HOLE);
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if (offset == (off_t)-1 || offset == stat.st_size)
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return EX_FAIL;
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return EX_OK;
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#else
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return EX_BAD;
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#endif
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}
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int
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main ()
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{
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#ifdef SEEK_HOLE
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int rc;
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char template[] = "testseekhole-XXXXXX";
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int fd = mkstemp (template);
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if (fd == -1)
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return EX_BAD;
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rc = check_seek_hole (fd);
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close (fd);
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unlink (template);
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return rc;
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#else
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return EX_FAIL;
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#endif
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}
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