// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2011 Oracle.  All rights reserved.
 * Copyright (C) 2011 Red Hat.  All rights reserved.
 */

#define _XOPEN_SOURCE 500
#define _FILE_OFFSET_BITS 64
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include "global.h"

#ifndef SEEK_DATA
#define SEEK_DATA      3
#define SEEK_HOLE      4
#endif

static blksize_t alloc_size;
int allow_default_behavior = 1;
int default_behavior = 0;
int unwritten_extents = 0;
int punch_hole = 0;
char *base_file_path;

static void get_file_system(int fd)
{
	struct statfs buf;

	if (!fstatfs(fd, &buf)) {
		fprintf(stdout, "File system magic#: 0x%lx\n",
				(unsigned long int)buf.f_type);
	}
}

static int get_io_sizes(int fd)
{
	off_t pos = 0, offset = 1;
	struct stat buf;
	int shift, ret;

	ret = fstat(fd, &buf);
	if (ret) {
		fprintf(stderr, "  ERROR %d: Failed to find io blocksize\n",
			errno);
		return ret;
	}

	/* st_blksize is typically also the allocation size */
	alloc_size = buf.st_blksize;

	/* try to discover the actual alloc size */
	while (pos == 0 && offset < alloc_size) {
		offset <<= 1;
		ftruncate(fd, 0);
		pwrite(fd, "a", 1, offset);
		pos = lseek(fd, 0, SEEK_DATA);
		if (pos == -1)
			goto fail;
	}

	/* bisect */
	shift = offset >> 2;
	while (shift && offset < alloc_size) {
		ftruncate(fd, 0);
		pwrite(fd, "a", 1, offset);
		pos = lseek(fd, 0, SEEK_DATA);
		if (pos == -1)
			goto fail;
		offset += pos ? -shift : shift;
		shift >>= 1;
	}
	if (!shift)
		offset += pos ? 0 : 1;
	alloc_size = offset;
	fprintf(stdout, "Allocation size: %ld\n", alloc_size);
	return 0;

fail:
	fprintf(stderr, "Kernel does not support llseek(2) extension "
		"SEEK_DATA. Aborting.\n");
	return -1;
}

#define do_free(x)     do { if(x) free(x); } while(0);

static void *do_malloc(size_t size)
{
       void *buf;

       buf = malloc(size);
       if (!buf)
               fprintf(stderr, "  ERROR: Unable to allocate %ld bytes\n",
                       (long)size);

       return buf;
}

static int do_truncate(int fd, off_t length)
{
       int ret;

       ret = ftruncate(fd, length);
       if (ret)
               fprintf(stderr, "  ERROR %d: Failed to extend file "
                       "to %ld bytes\n", errno, (long)length);
       return ret;
}

static int do_fallocate(int fd, off_t offset, off_t length, int mode)
{
	int ret;

	ret = fallocate(fd, mode, offset, length);
	if (ret)
		fprintf(stderr, "  ERROR %d: Failed to %s of %ld bytes\n",
			errno, (mode & FALLOC_FL_PUNCH_HOLE) ? "punch hole" :
			"preallocate space", (long) length);

	return ret;
}

/*
 * Synchnorize all dirty pages in the file range starting from
 * offset to nbytes length.
 */
static int do_sync_dirty_pages(int fd, off64_t offset, off64_t nbytes)
{
	int ret;

	ret = sync_file_range(fd, offset, nbytes, SYNC_FILE_RANGE_WRITE);
	if (ret)
		fprintf(stderr, "  ERROR %d: Failed to sync out dirty "
			"pages\n", errno);

	return ret;
}

static ssize_t do_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
	ssize_t ret, written = 0;

	while (count > written) {
		ret = pwrite(fd, buf + written, count - written, offset + written);
		if (ret < 0) {
			/* Don't warn about too large file. It's fs dependent. */
			if (errno == EFBIG)
				return ret;
			fprintf(stderr, "  ERROR %d: Failed to write %ld "
				"bytes\n", errno, (long)count);
			return ret;
		}
		written += ret;
	}

	return 0;
}

#define do_close(x)	do { if ((x) > -1) close(x); } while(0);

static int do_create(const char *filename)
{
	int fd;

	fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0644);
	if (fd < 0)
		fprintf(stderr, " ERROR %d: Failed to create file '%s'\n",
			errno, filename);

	return fd;
}

static int do_lseek(int testnum, int subtest, int fd, off_t filsz, int origin,
		    off_t set, off_t exp)
{
	off_t pos, exp2;
	int x, ret;

	assert(!(origin != SEEK_HOLE && origin != SEEK_DATA));

	/*
	 * The file pointer can be set to different values depending
	 * on the implementation. For SEEK_HOLE, EOF could be a valid
	 * value. For SEEK_DATA, supplied offset could be the valid
	 * value.
	 */
	exp2 = exp;
	if (origin == SEEK_HOLE && exp2 != -1)
		exp2 = filsz;
	if (origin == SEEK_DATA && default_behavior && set < filsz)
		exp2 = set;

	pos = lseek(fd, set, origin);

	if (pos == -1 && exp == -1) {
		x = fprintf(stdout, "%02d.%02d %s expected -1 with errno %d, got %d. ",
			    testnum, subtest,
			    (origin == SEEK_HOLE) ? "SEEK_HOLE" : "SEEK_DATA",
			    -ENXIO, -errno);
		ret = !(errno == ENXIO);
	} else {

		x = fprintf(stdout, "%02d.%02d %s expected %lld or %lld, got %lld. ",
			    testnum, subtest,
			    (origin == SEEK_HOLE) ? "SEEK_HOLE" : "SEEK_DATA",
			    (long long)exp, (long long)exp2, (long long)pos);
		ret = !(pos == exp || pos == exp2);
	}

	fprintf(stdout, "%*s\n", (70 - x), ret ? "FAIL" : "succ");

	return ret;
}

static int huge_file_test(int fd, int testnum, off_t filsz)
{
	char *buf = NULL;
	int bufsz = alloc_size * 16;	/* XFS seems to round allocated size */
	off_t off = filsz - bufsz;
	int ret = -1;

	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* |- DATA -|- HUGE HOLE -|- DATA -| */
	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;
	ret = do_pwrite(fd, buf, bufsz, off);
	if (ret) {
		/*
		 * Report success. Filesystem just cannot handle so large
		 * offsets and correctly reports it.
		 */
		if (errno == EFBIG) {
			fprintf(stdout, "Test skipped as fs doesn't support so large files.\n");
			ret = 0;
		}
		goto out;
	}

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);

	/* offset around eof */
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_HOLE, off, off + bufsz);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, off, off);
	ret += do_lseek(testnum,  7, fd, filsz, SEEK_DATA, off + 1, off + 1);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_DATA, off - bufsz, off);

out:
	do_free(buf);
	return ret;
}

/*
 * Make sure hole size is properly reported when punched in the middle of a file
 */
static int test21(int fd, int testnum)
{
	char *buf = NULL;
	int bufsz, filsz;
	int ret = 0;

	if (!punch_hole) {
		fprintf(stdout, "Test skipped as fs doesn't support punch hole.\n");
		goto out;
	}

	if (default_behavior) {
		fprintf(stdout, "Test skipped as fs doesn't support seeking a punched hole.\n");
		goto out;
	}

	bufsz = alloc_size * 3;
	buf = do_malloc(bufsz);
	if (!buf) {
		ret = -1;
		goto out;
	}
	memset(buf, 'a', bufsz);

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	filsz = bufsz;
	ret = do_fallocate(fd, alloc_size, alloc_size,
			   FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
	if (ret < 0)
		goto out;

	ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum, 2, fd, filsz, SEEK_HOLE, 0, alloc_size);
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA, alloc_size, alloc_size * 2);
out:
	if (buf)
		free(buf);
	return ret;
}

/*
 * Make sure hole size is properly reported when starting in the middle of a
 * hole in ext? doubly indirect tree
 */
static int test20(int fd, int testnum)
{
	int ret = -1;
	char *buf = NULL;
	loff_t bufsz, filsz;

	bufsz = alloc_size;
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* Magic size in the middle of ext[23] triple indirect tree */
	filsz = (12 + bufsz / 4 + 8 * bufsz / 4 * bufsz / 4 + 2 * bufsz / 4 + 5) * bufsz;
	ret = do_pwrite(fd, buf, bufsz, filsz - bufsz);
	if (ret) {
		/*
		 * Report success. Filesystem just cannot handle so large
		 * offsets and correctly reports it.
		 */
		if (errno == EFBIG) {
			fprintf(stdout, "Test skipped as fs doesn't support so large files.\n");
			ret = 0;
		}
		goto out;
	}

	/* Offset inside ext[23] indirect block */
	ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, 14 * bufsz, filsz - bufsz);
	/* Offset inside ext[23] doubly indirect block */
	ret += do_lseek(testnum, 2, fd, filsz, SEEK_DATA, (12 + 2 * bufsz / 4) * bufsz, filsz - bufsz);
	/* Offsets inside ext[23] triply indirect block */
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
		(12 + bufsz / 4 + bufsz / 4 * bufsz / 4 + 3 * bufsz / 4 + 5) * bufsz, filsz - bufsz);
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
		(12 + bufsz / 4 + 7 * bufsz / 4 * bufsz / 4 + 5 * bufsz / 4) * bufsz, filsz - bufsz);
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
		(12 + bufsz / 4 + 8 * bufsz / 4 * bufsz / 4 + bufsz / 4 + 11) * bufsz, filsz - bufsz);
out:
	if (buf)
		free(buf);
	return ret;
}
/*
 * Make sure hole size is properly reported when starting in the middle of a
 * hole in ext? indirect tree
 */
static int test19(int fd, int testnum)
{
	int ret = -1;
	char *buf = NULL;
	int bufsz, filsz;

	bufsz = alloc_size;
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* Magic size just beyond ext[23] indirect tree size */
	filsz = (12 + bufsz / 4 + 1) * bufsz;
	ret = do_pwrite(fd, buf, bufsz, filsz - bufsz);
	if (ret)
		goto out;

	ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, bufsz, filsz - bufsz);
	ret += do_lseek(testnum, 2, fd, filsz, SEEK_DATA, 12*bufsz, filsz - bufsz);
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA, (12 + bufsz / 4 - 8)*bufsz, filsz - bufsz);
out:
	if (buf)
		free(buf);
	return ret;
}

/* Make sure we get ENXIO if we pass in a negative offset. */
static int test18(int fd, int testnum)
{
	int ret = 0;

	/* file size doesn't matter in this test, set to 0 */
	ret += do_lseek(testnum, 1, fd, 0, SEEK_HOLE, -1, -1);
	ret += do_lseek(testnum, 2, fd, 0, SEEK_DATA, -1, -1);

	return ret;
}

static int test17(int fd, int testnum)
{
	char *buf = NULL;
	int pagesz = sysconf(_SC_PAGE_SIZE);
	int bufsz, filsz;
	int ret = 0;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	if (pagesz < 4 * alloc_size) {
		fprintf(stdout, "Test skipped as page size (%d) is less than "
			"four times allocation size (%d).\n",
			pagesz, (int)alloc_size);
		goto out;
	}
	bufsz = alloc_size;
	filsz = 3 * bufsz;

	buf = do_malloc(bufsz);
	if (!buf) {
		ret = -1;
		goto out;
	}
	memset(buf, 'a', bufsz);

	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 2 * bufsz);
	if (ret)
		goto out;

	ret += do_lseek(testnum,  1, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 1, 1);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_DATA, bufsz, 2 * bufsz);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_HOLE, bufsz, bufsz);
	ret += do_lseek(testnum,  7, fd, filsz, SEEK_DATA, bufsz + 1, 2 * bufsz);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_HOLE, bufsz + 1, bufsz + 1);
	ret += do_lseek(testnum,  9, fd, filsz, SEEK_DATA, 2 * bufsz, 2 * bufsz);
	ret += do_lseek(testnum, 10, fd, filsz, SEEK_HOLE, 2 * bufsz, 3 * bufsz);
	ret += do_lseek(testnum, 11, fd, filsz, SEEK_DATA, 2 * bufsz + 1, 2 * bufsz + 1);
	ret += do_lseek(testnum, 12, fd, filsz, SEEK_HOLE, 2 * bufsz + 1, 3 * bufsz);

	filsz += bufsz;
	ret += do_fallocate(fd, 0, filsz, 0);

	ret += do_lseek(testnum, 13, fd, filsz, SEEK_DATA, 3 * bufsz, -1);
	ret += do_lseek(testnum, 14, fd, filsz, SEEK_HOLE, 3 * bufsz, 3 * bufsz);
	ret += do_lseek(testnum, 15, fd, filsz, SEEK_DATA, 3 * bufsz + 1, -1);
	ret += do_lseek(testnum, 16, fd, filsz, SEEK_HOLE, 3 * bufsz + 1, 3 * bufsz + 1);

out:
	do_free(buf);
	return ret;
}

/*
 * test file with unwritten extents, having non-contiguous dirty pages in
 * the unwritten extent.
 */
static int test16(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = sysconf(_SC_PAGE_SIZE);
	int filsz = 4 << 20;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in dirty page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, filsz/2);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_DATA, bufsz, filsz/2);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_HOLE, filsz/2,
			filsz/2 + bufsz);

out:
	do_free(buf);
	return ret;
}

/*
 * test file with unwritten extents, having page just after end of unwritten
 * extent.
 */
static int test15(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = sysconf(_SC_PAGE_SIZE);
	int filsz = 4 << 20;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in dirty page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	/* One page written just after end of unwritten extent... */
	ret = do_pwrite(fd, buf, bufsz, filsz);
	if (ret)
		goto out;

	/* update file size */
	filsz += bufsz;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_DATA, bufsz, filsz - bufsz);

out:
	do_free(buf);
	return ret;
}

/*
 * test file with unwritten extents, only have pagevec worth of dirty pages
 * in page cache, a hole and then another page.
 */
static int test14(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = sysconf(_SC_PAGE_SIZE) * 14;
	int filsz = 4 << 20;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in dirty page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 3 * bufsz);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_HOLE, 3 * bufsz, 4 * bufsz);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_DATA, 1, 1);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, bufsz, 3 * bufsz);

out:
	do_free(buf);
	return ret;
}

/*
 * test file with unwritten extents, only have pagevec worth of dirty pages
 * in page cache.
 */
static int test13(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = sysconf(_SC_PAGE_SIZE) * 14;
	int filsz = 4 << 20;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in dirty page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);

out:
	do_free(buf);
	return ret;
}

/*
 * Test huge file to check for overflows of block counts due to usage of
 * 32-bit types.
 */
static int test12(int fd, int testnum)
{
	return huge_file_test(fd, testnum,
				((long long)alloc_size << 32) + (1 << 20));
}

/*
 * Test huge file to check for overflows of block counts due to usage of
 * signed types
 */
static int test11(int fd, int testnum)
{
	return huge_file_test(fd, testnum,
				((long long)alloc_size << 31) + (1 << 20));
}

/* Test an 8G file to check for offset overflows at 1 << 32 */
static int test10(int fd, int testnum)
{
	return huge_file_test(fd, testnum, 8ULL << 30);
}

/*
 * test file with unwritten extents, have both dirty and
 * writeback pages in page cache.
 */
static int test09(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = alloc_size;
	int filsz = bufsz * 100 + bufsz;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/*
	 * HOLE - unwritten DATA in dirty page - HOLE -
	 * unwritten DATA in writeback page
	 */

	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 8M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, bufsz * 10);
	if (!ret) {
		ret = do_pwrite(fd, buf, bufsz, bufsz * 100);
		if (ret)
			goto out;
	}

	/*
	 * Sync out dirty pages from bufsz * 100, this will convert
	 * the dirty page to writeback.
	 */
	ret = do_sync_dirty_pages(fd, bufsz * 100, 0);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, 1);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, bufsz * 10);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, bufsz * 10);

out:
	do_free(buf);
	return ret;
}

/* test file with unwritten extent, only have writeback page */
static int test08(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = alloc_size;
	int filsz = bufsz * 10 + bufsz;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in writeback page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, bufsz * 10);
	if (ret)
		goto out;

	/* Sync out all file */
	ret = do_sync_dirty_pages(fd, 0, 0);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, 1);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, bufsz * 10);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, bufsz * 10);

out:
	do_free(buf);
	return ret;
}

/*
 * test file with unwritten extents, only have dirty pages
 * in page cache.
 */
static int test07(int fd, int testnum)
{
	int ret = 0;
	char *buf = NULL;
	int bufsz = alloc_size;
	int filsz = bufsz * 10 + bufsz;

	if (!unwritten_extents) {
		fprintf(stdout, "Test skipped as fs doesn't support unwritten extents.\n");
		goto out;
	}

	/* HOLE - unwritten DATA in dirty page */
	/* Each unit is bufsz */
	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* preallocate 4M space to file */
	ret = do_fallocate(fd, 0, filsz, 0);
	if (ret < 0)
		goto out;

	ret = do_pwrite(fd, buf, bufsz, bufsz * 10);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, 1);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, bufsz * 10);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, bufsz * 10);

out:
	do_free(buf);
	return ret;
}

/* test hole data hole data */
static int test06(int fd, int testnum)
{
	int ret = -1;
	char *buf = NULL;
	int bufsz = alloc_size;
	int filsz = bufsz * 4;
	int off;

	/* HOLE - DATA - HOLE - DATA */
	/* Each unit is bufsz */

	buf = do_malloc(bufsz);
	if (!buf)
		goto out;

	memset(buf, 'a', bufsz);

	ret = do_pwrite(fd, buf, bufsz, bufsz);
	if (!ret)
		do_pwrite(fd, buf, bufsz, bufsz * 3);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, 1);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, bufsz);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, bufsz);

	/* offset around first hole-data boundary */
	off = bufsz;
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_HOLE, off - 1, off - 1);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, off - 1, off);
	ret += do_lseek(testnum,  7, fd, filsz, SEEK_HOLE, off,     bufsz * 2);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_DATA, off,     off);
	ret += do_lseek(testnum,  9, fd, filsz, SEEK_HOLE, off + 1, bufsz * 2);
	ret += do_lseek(testnum, 10, fd, filsz, SEEK_DATA, off + 1, off + 1);

	/* offset around data-hole boundary */
	off = bufsz * 2;
	ret += do_lseek(testnum, 11, fd, filsz, SEEK_HOLE, off - 1, off);
	ret += do_lseek(testnum, 12, fd, filsz, SEEK_DATA, off - 1, off - 1);
	ret += do_lseek(testnum, 13, fd, filsz, SEEK_HOLE, off,     off);
	ret += do_lseek(testnum, 14, fd, filsz, SEEK_DATA, off,     bufsz * 3);
	ret += do_lseek(testnum, 15, fd, filsz, SEEK_HOLE, off + 1, off + 1);
	ret += do_lseek(testnum, 16, fd, filsz, SEEK_DATA, off + 1, bufsz * 3);

	/* offset around second hole-data boundary */
	off = bufsz * 3;
	ret += do_lseek(testnum, 17, fd, filsz, SEEK_HOLE, off - 1, off - 1);
	ret += do_lseek(testnum, 18, fd, filsz, SEEK_DATA, off - 1, off);
	ret += do_lseek(testnum, 19, fd, filsz, SEEK_HOLE, off,     filsz);
	ret += do_lseek(testnum, 20, fd, filsz, SEEK_DATA, off,     off);
	ret += do_lseek(testnum, 21, fd, filsz, SEEK_HOLE, off + 1, filsz);
	ret += do_lseek(testnum, 22, fd, filsz, SEEK_DATA, off + 1, off + 1);

	/* offset around the end of file */
	off = filsz;
	ret += do_lseek(testnum, 23, fd, filsz, SEEK_HOLE, off - 1, filsz);
	ret += do_lseek(testnum, 24, fd, filsz, SEEK_DATA, off - 1, filsz - 1);
	ret += do_lseek(testnum, 25, fd, filsz, SEEK_HOLE, off, -1);
	ret += do_lseek(testnum, 26, fd, filsz, SEEK_DATA, off, -1);
	ret += do_lseek(testnum, 27, fd, filsz, SEEK_HOLE, off + 1, -1);
	ret += do_lseek(testnum, 28, fd, filsz, SEEK_DATA, off + 1, -1);

out:
	do_free(buf);
	return ret;
}

/* test file with data at the beginning and a hole at the end */
static int test05(int fd, int testnum)
{
	int ret = -1;
	char *buf = NULL;
	int bufsz = alloc_size;
	int filsz = bufsz * 4;

	/* |- DATA -|- HOLE -|- HOLE -|- HOLE -| */

	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	ret = do_truncate(fd, filsz);
	if (!ret)
		ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	/* offset at the beginning */

	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);

	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);

	/* offset around data-hole boundary */
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_HOLE, bufsz - 1, bufsz);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, bufsz - 1, bufsz - 1);

	ret += do_lseek(testnum,  7, fd, filsz, SEEK_HOLE, bufsz,     bufsz);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_DATA, bufsz,     -1);
	ret += do_lseek(testnum,  9, fd, filsz, SEEK_HOLE, bufsz + 1, bufsz + 1);
	ret += do_lseek(testnum, 10, fd, filsz, SEEK_DATA, bufsz + 1, -1);

	/* offset around eof */
	ret += do_lseek(testnum, 11, fd, filsz, SEEK_HOLE, filsz - 1, filsz - 1);
	ret += do_lseek(testnum, 12, fd, filsz, SEEK_DATA, filsz - 1, -1);
	ret += do_lseek(testnum, 13, fd, filsz, SEEK_HOLE, filsz,     -1);
	ret += do_lseek(testnum, 14, fd, filsz, SEEK_DATA, filsz,     -1);
	ret += do_lseek(testnum, 15, fd, filsz, SEEK_HOLE, filsz + 1, -1);
	ret += do_lseek(testnum, 16, fd, filsz, SEEK_DATA, filsz + 1, -1);
out:
	do_free(buf);
	return ret;
}
/* test hole begin and data end */
static int test04(int fd, int testnum)
{
	int ret;
	char *buf = "ABCDEFGH";
	int bufsz, holsz, filsz;

	bufsz = strlen(buf);
	holsz = alloc_size * 2;
	filsz = holsz + bufsz;

	/* |- HOLE -|- HOLE -|- DATA -| */

	ret = do_pwrite(fd, buf, bufsz, holsz);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, 0);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, 1);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, holsz);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, holsz);
	/* offset around hole-data boundary */
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_HOLE, holsz - 1, holsz - 1);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, holsz - 1, holsz);
	ret += do_lseek(testnum,  7, fd, filsz, SEEK_HOLE, holsz,     filsz);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_DATA, holsz,     holsz);
	ret += do_lseek(testnum,  9, fd, filsz, SEEK_HOLE, holsz + 1, filsz);
	ret += do_lseek(testnum, 10, fd, filsz, SEEK_DATA, holsz + 1, holsz + 1);

	/* offset around eof */
	ret += do_lseek(testnum, 11, fd, filsz, SEEK_HOLE, filsz - 1, filsz);
	ret += do_lseek(testnum, 12, fd, filsz, SEEK_DATA, filsz - 1, filsz - 1);
	ret += do_lseek(testnum, 13, fd, filsz, SEEK_HOLE, filsz,     -1);
	ret += do_lseek(testnum, 14, fd, filsz, SEEK_DATA, filsz,     -1);
	ret += do_lseek(testnum, 15, fd, filsz, SEEK_HOLE, filsz + 1, -1);
	ret += do_lseek(testnum, 16, fd, filsz, SEEK_DATA, filsz + 1, -1);
out:
	return ret;
}

/* test a larger full file */
static int test03(int fd, int testnum)
{
	char *buf = NULL;
	int bufsz = alloc_size * 2 + 100;
	int filsz = bufsz;
	int ret = -1;

	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	/* offset at the beginning */
	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);

	/* offset around eof */
	ret += do_lseek(testnum,  5, fd, filsz, SEEK_HOLE, bufsz - 1, bufsz);
	ret += do_lseek(testnum,  6, fd, filsz, SEEK_DATA, bufsz - 1, bufsz - 1);
	ret += do_lseek(testnum,  7, fd, filsz, SEEK_HOLE, bufsz,     -1);
	ret += do_lseek(testnum,  8, fd, filsz, SEEK_DATA, bufsz,     -1);
	ret += do_lseek(testnum,  9, fd, filsz, SEEK_HOLE, bufsz + 1, -1);
	ret += do_lseek(testnum, 10, fd, filsz, SEEK_DATA, bufsz + 1, -1);

out:
	do_free(buf);
	return ret;
}

/* test tiny full file */
static int test02(int fd, int testnum)
{
	int ret;
	char buf[] = "ABCDEFGH";
	int bufsz, filsz;

	bufsz = strlen(buf);
	filsz = bufsz;

	/* |- DATA -| */

	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	ret += do_lseek(testnum, 1, fd, filsz, SEEK_HOLE, 0, filsz);
	ret += do_lseek(testnum, 2, fd, filsz, SEEK_DATA, 0, 0);
	ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA, 1, 1);
	ret += do_lseek(testnum, 4, fd, filsz, SEEK_HOLE, bufsz - 1, filsz);
	ret += do_lseek(testnum, 5, fd, filsz, SEEK_DATA, bufsz - 1, bufsz - 1);
	ret += do_lseek(testnum, 6, fd, filsz, SEEK_HOLE, bufsz,     -1);
	ret += do_lseek(testnum, 7, fd, filsz, SEEK_DATA, bufsz,     -1);
	ret += do_lseek(testnum, 8, fd, filsz, SEEK_HOLE, bufsz + 1, -1);
	ret += do_lseek(testnum, 9, fd, filsz, SEEK_DATA, bufsz + 1, -1);

out:
	return ret;
}

/* test empty file */
static int test01(int fd, int testnum)
{
	int ret = 0;

	ret += do_lseek(testnum, 1, fd, 0, SEEK_DATA, 0, -1);
	ret += do_lseek(testnum, 2, fd, 0, SEEK_HOLE, 0, -1);
	ret += do_lseek(testnum, 3, fd, 0, SEEK_HOLE, 1, -1);

	return ret;
}

struct testrec {
       int     test_num;
       int     (*test_func)(int fd, int testnum);
       char    *test_desc;
};

struct testrec seek_tests[] = {
       {  1, test01, "Test empty file" },
       {  2, test02, "Test a tiny full file" },
       {  3, test03, "Test a larger full file" },
       {  4, test04, "Test file hole at beg, data at end" },
       {  5, test05, "Test file data at beg, hole at end" },
       {  6, test06, "Test file hole data hole data" },
       {  7, test07, "Test file with unwritten extents, only have dirty pages" },
       {  8, test08, "Test file with unwritten extents, only have unwritten pages" },
       {  9, test09, "Test file with unwritten extents, have both dirty && unwritten pages" },
       { 10, test10, "Test a huge file for offset overflow" },
       { 11, test11, "Test a huge file for block number signed" },
       { 12, test12, "Test a huge file for block number overflow" },
       { 13, test13, "Test file with unwritten extents, only have pagevec dirty pages" },
       { 14, test14, "Test file with unwritten extents, small hole after pagevec dirty pages" },
       { 15, test15, "Test file with unwritten extents, page after unwritten extent" },
       { 16, test16, "Test file with unwritten extents, non-contiguous dirty pages" },
       { 17, test17, "Test file with unwritten extents, data-hole-data inside page" },
       { 18, test18, "Test file with negative SEEK_{HOLE,DATA} offsets" },
       { 19, test19, "Test file SEEK_DATA from middle of a large hole" },
       { 20, test20, "Test file SEEK_DATA from middle of a huge hole" },
       { 21, test21, "Test file SEEK_HOLE that was created by PUNCH_HOLE" },
};

static int run_test(struct testrec *tr)
{
	int ret = 0, fd = -1;
	char filename[255];

	snprintf(filename, sizeof(filename), "%s%02d", base_file_path, tr->test_num);

	fd = do_create(filename);
	if (fd > -1) {
		printf("%02d. %-50s\n", tr->test_num, tr->test_desc);
		ret = tr->test_func(fd, tr->test_num);
		printf("\n");
	}

	do_close(fd);
	return ret;
}

static int test_basic_support(void)
{
	int ret = -1, fd;
	off_t pos;
	char *buf = NULL;
	int bufsz, filsz;

	fd = do_create(base_file_path);
	if (fd == -1)
		goto out;

	get_file_system(fd);

	ret = get_io_sizes(fd);
	if (ret)
		goto out;

	ftruncate(fd, 0);
	bufsz = alloc_size * 2;
	filsz = bufsz * 2;

	buf = do_malloc(bufsz);
	if (!buf)
		goto out;
	memset(buf, 'a', bufsz);

	/* File with 2 allocated blocks.... */
	ret = do_pwrite(fd, buf, bufsz, 0);
	if (ret)
		goto out;

	/* followed by a hole... */
	ret = do_truncate(fd, filsz);
	if (ret)
		goto out;

	/* Is SEEK_DATA supported in the kernel? */
	pos = lseek(fd, 0, SEEK_DATA);
	if (pos == -1) {
		fprintf(stderr, "Kernel does not support llseek(2) extension "
			"SEEK_DATA. Aborting.\n");
		ret = -1;
		goto out;
	}

	/* Is SEEK_HOLE supported in the kernel? */
	pos = lseek(fd, 0, SEEK_HOLE);
	if (pos == -1) {
		fprintf(stderr, "Kernel does not support llseek(2) extension "
			"SEEK_HOLE. Aborting.\n");
		ret = -1;
		goto out;
	}

	if (pos == filsz) {
		default_behavior = 1;
		fprintf(stderr, "File system supports the default behavior.\n");
	}

	if (default_behavior && !allow_default_behavior) {
		fprintf(stderr, "Default behavior is not allowed. Aborting.\n");
		ret = -1;
		goto out;
	}

	/* Is unwritten extent supported? */
	ftruncate(fd, 0);
	if (fallocate(fd, 0, 0, alloc_size * 2) == -1) {
		if (errno == EOPNOTSUPP) {
			fprintf(stderr, "File system does not support fallocate.\n");
		} else {
			fprintf(stderr, "ERROR %d: Failed to preallocate "
				"space to %ld bytes. Aborting.\n", errno, (long) alloc_size);
			ret = -1;
		}
		goto out;
	}

	pos = lseek(fd, 0, SEEK_DATA);
	if (pos == 0)
		fprintf(stderr, "File system does not support unwritten extents.\n");
	else
		unwritten_extents = 1;

	/* Is punch hole supported? */
	if (fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
		      0, alloc_size) == -1)
		fprintf(stderr, "File system does not support punch hole.\n");
	else
		punch_hole = 1;

	printf("\n");

out:
	do_free(buf);
	do_close(fd);
	return ret;
}

void usage(char *cmd)
{
	fprintf(stdout, "Usage: %s [-tf] [-s <starttest>] [-e <endtest>] base_file_path\n", cmd);
	exit(1);
}

int main(int argc, char **argv)
{
	int ret = -1;
	int i = 0;
	int opt;
	int check_support = 0;
	int numtests = sizeof(seek_tests) / sizeof(struct testrec);
	int teststart, testend;

	/*
	 * First twelve tests are used by generic/285. To run these is the
	 * default. Further tests are run e.g. by generic/436. They are not
	 * run by default in order to not regress older kernels.
	 */
	teststart = 1;
	testend = 12;

	while ((opt = getopt(argc, argv, "tfs:e:")) != -1) {
		switch (opt) {
		case 't':
			check_support++;
			break;
		case 'f':
			allow_default_behavior = 0;
			break;
		case 's':
			teststart = strtol(optarg, NULL, 10);
			if (teststart <= 0 || teststart > numtests) {
				fprintf(stdout, "Invalid starting test: %s\n",
					optarg);
				usage(argv[0]);
			}
			break;
		case 'e':
			testend = strtol(optarg, NULL, 10);
			if (testend <= 0 || testend > numtests) {
				fprintf(stdout, "Invalid final test: %s\n",
					optarg);
				usage(argv[0]);
			}
			break;
		default:
			usage(argv[0]);
		}
	}

	/* should be exactly one arg left, the filename */
	if (optind != argc - 1)
		usage(argv[0]);

	if (teststart > testend) {
		fprintf(stdout, "Starting test is larger than final test!\n");
		usage(argv[0]);
	}

	base_file_path = (char *)strdup(argv[optind]);

	ret = test_basic_support();
	if (ret || check_support)
		goto out;

	for (i = 0; i < numtests; ++i) {
		if (seek_tests[i].test_num >= teststart &&
		    seek_tests[i].test_num <= testend) {
			ret = run_test(&seek_tests[i]);
			if (ret)
				break;
		}
	}

out:
	free(base_file_path);
	return ret;
}