fs/btrfs/tests/extent-io-tests.c - SHIFTPHONES/mainline/linux - Gitiles

 /*
  * Copyright (C) 2013 Fusion IO.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License v2 as published by the Free Software Foundation.
  *
  * This program 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
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public
  * License along with this program; if not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * Boston, MA 021110-1307, USA.
  */

 #include <linux/pagemap.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/sizes.h>
 #include "btrfs-tests.h"
 #include "../extent_io.h"

 #define PROCESS_UNLOCK		(1 << 0)
 #define PROCESS_RELEASE		(1 << 1)
 #define PROCESS_TEST_LOCKED	(1 << 2)

 static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
 				       unsigned long flags)
 {
 	int ret;
 	struct page *pages[16];
 	unsigned long index = start >> PAGE_SHIFT;
 	unsigned long end_index = end >> PAGE_SHIFT;
 	unsigned long nr_pages = end_index - index + 1;
 	int i;
 	int count = 0;
 	int loops = 0;

 	while (nr_pages > 0) {
 		ret = find_get_pages_contig(inode->i_mapping, index,
 				     min_t(unsigned long, nr_pages,
 				     ARRAY_SIZE(pages)), pages);
 		for (i = 0; i < ret; i++) {
 			if (flags & PROCESS_TEST_LOCKED &&
 			    !PageLocked(pages[i]))
 				count++;
 			if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
 				unlock_page(pages[i]);
 			put_page(pages[i]);
 			if (flags & PROCESS_RELEASE)
 				put_page(pages[i]);
 		}
 		nr_pages -= ret;
 		index += ret;
 		cond_resched();
 		loops++;
 		if (loops > 100000) {
 			printk(KERN_ERR "stuck in a loop, start %Lu, end %Lu, nr_pages %lu, ret %d\n", start, end, nr_pages, ret);
 			break;
 		}
 	}
 	return count;
 }

 static int test_find_delalloc(void)
 {
 	struct inode *inode;
 	struct extent_io_tree tmp;
 	struct page *page;
 	struct page *locked_page = NULL;
 	unsigned long index = 0;
 	u64 total_dirty = SZ_256M;
 	u64 max_bytes = SZ_128M;
 	u64 start, end, test_start;
 	u64 found;
 	int ret = -EINVAL;

 	test_msg("Running find delalloc tests\n");

 	inode = btrfs_new_test_inode();
 	if (!inode) {
 		test_msg("Failed to allocate test inode\n");
 		return -ENOMEM;
 	}

 	extent_io_tree_init(&tmp, &inode->i_data);

 	/*
 	 * First go through and create and mark all of our pages dirty, we pin
 	 * everything to make sure our pages don't get evicted and screw up our
 	 * test.
 	 */
 	for (index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
 		page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
 		if (!page) {
 			test_msg("Failed to allocate test page\n");
 			ret = -ENOMEM;
 			goto out;
 		}
 		SetPageDirty(page);
 		if (index) {
 			unlock_page(page);
 		} else {
 			get_page(page);
 			locked_page = page;
 		}
 	}

 	/* Test this scenario
 	 * |--- delalloc ---|
 	 * |---  search  ---|
 	 */
 	set_extent_delalloc(&tmp, 0, 4095, NULL, GFP_KERNEL);
 	start = 0;
 	end = 0;
 	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 					 &end, max_bytes);
 	if (!found) {
 		test_msg("Should have found at least one delalloc\n");
 		goto out_bits;
 	}
 	if (start != 0 || end != 4095) {
 		test_msg("Expected start 0 end 4095, got start %Lu end %Lu\n",
 			 start, end);
 		goto out_bits;
 	}
 	unlock_extent(&tmp, start, end);
 	unlock_page(locked_page);
 	put_page(locked_page);

 	/*
 	 * Test this scenario
 	 *
 	 * |--- delalloc ---|
 	 *           |--- search ---|
 	 */
 	test_start = SZ_64M;
 	locked_page = find_lock_page(inode->i_mapping,
 				     test_start >> PAGE_SHIFT);
 	if (!locked_page) {
 		test_msg("Couldn't find the locked page\n");
 		goto out_bits;
 	}
 	set_extent_delalloc(&tmp, 4096, max_bytes - 1, NULL, GFP_KERNEL);
 	start = test_start;
 	end = 0;
 	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 					 &end, max_bytes);
 	if (!found) {
 		test_msg("Couldn't find delalloc in our range\n");
 		goto out_bits;
 	}
 	if (start != test_start || end != max_bytes - 1) {
 		test_msg("Expected start %Lu end %Lu, got start %Lu, end "
 			 "%Lu\n", test_start, max_bytes - 1, start, end);
 		goto out_bits;
 	}
 	if (process_page_range(inode, start, end,
 			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 		test_msg("There were unlocked pages in the range\n");
 		goto out_bits;
 	}
 	unlock_extent(&tmp, start, end);
 	/* locked_page was unlocked above */
 	put_page(locked_page);

 	/*
 	 * Test this scenario
 	 * |--- delalloc ---|
 	 *                    |--- search ---|
 	 */
 	test_start = max_bytes + 4096;
 	locked_page = find_lock_page(inode->i_mapping, test_start >>
 				     PAGE_SHIFT);
 	if (!locked_page) {
 		test_msg("Could'nt find the locked page\n");
 		goto out_bits;
 	}
 	start = test_start;
 	end = 0;
 	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 					 &end, max_bytes);
 	if (found) {
 		test_msg("Found range when we shouldn't have\n");
 		goto out_bits;
 	}
 	if (end != (u64)-1) {
 		test_msg("Did not return the proper end offset\n");
 		goto out_bits;
 	}

 	/*
 	 * Test this scenario
 	 * [------- delalloc -------|
 	 * [max_bytes]|-- search--|
 	 *
 	 * We are re-using our test_start from above since it works out well.
 	 */
 	set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, NULL, GFP_KERNEL);
 	start = test_start;
 	end = 0;
 	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 					 &end, max_bytes);
 	if (!found) {
 		test_msg("Didn't find our range\n");
 		goto out_bits;
 	}
 	if (start != test_start || end != total_dirty - 1) {
 		test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 			 test_start, total_dirty - 1, start, end);
 		goto out_bits;
 	}
 	if (process_page_range(inode, start, end,
 			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 		test_msg("Pages in range were not all locked\n");
 		goto out_bits;
 	}
 	unlock_extent(&tmp, start, end);

 	/*
 	 * Now to test where we run into a page that is no longer dirty in the
 	 * range we want to find.
 	 */
 	page = find_get_page(inode->i_mapping,
 			     (max_bytes + SZ_1M) >> PAGE_SHIFT);
 	if (!page) {
 		test_msg("Couldn't find our page\n");
 		goto out_bits;
 	}
 	ClearPageDirty(page);
 	put_page(page);

 	/* We unlocked it in the previous test */
 	lock_page(locked_page);
 	start = test_start;
 	end = 0;
 	/*
 	 * Currently if we fail to find dirty pages in the delalloc range we
 	 * will adjust max_bytes down to PAGE_CACHE_SIZE and then re-search.  If
 	 * this changes at any point in the future we will need to fix this
 	 * tests expected behavior.
 	 */
 	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 					 &end, max_bytes);
 	if (!found) {
 		test_msg("Didn't find our range\n");
 		goto out_bits;
 	}
 	if (start != test_start && end != test_start + PAGE_SIZE - 1) {
 		test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 			 test_start, test_start + PAGE_SIZE - 1, start,
 			 end);
 		goto out_bits;
 	}
 	if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
 			       PROCESS_UNLOCK)) {
 		test_msg("Pages in range were not all locked\n");
 		goto out_bits;
 	}
 	ret = 0;
 out_bits:
 	clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_KERNEL);
 out:
 	if (locked_page)
 		put_page(locked_page);
 	process_page_range(inode, 0, total_dirty - 1,
 			   PROCESS_UNLOCK | PROCESS_RELEASE);
 	iput(inode);
 	return ret;
 }

 static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
 			     unsigned long len)
 {
 	unsigned long i, x;

 	memset(bitmap, 0, len);
 	memset_extent_buffer(eb, 0, 0, len);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Bitmap was not zeroed\n");
 		return -EINVAL;
 	}

 	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
 	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Setting all bits failed\n");
 		return -EINVAL;
 	}

 	bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
 	extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Clearing all bits failed\n");
 		return -EINVAL;
 	}

 	bitmap_set(bitmap, (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 		   sizeof(long) * BITS_PER_BYTE);
 	extent_buffer_bitmap_set(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 				 sizeof(long) * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Setting straddling pages failed\n");
 		return -EINVAL;
 	}

 	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
 	bitmap_clear(bitmap,
 		     (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 		     sizeof(long) * BITS_PER_BYTE);
 	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
 	extent_buffer_bitmap_clear(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 				   sizeof(long) * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Clearing straddling pages failed\n");
 		return -EINVAL;
 	}

 	/*
 	 * Generate a wonky pseudo-random bit pattern for the sake of not using
 	 * something repetitive that could miss some hypothetical off-by-n bug.
 	 */
 	x = 0;
 	for (i = 0; i < len / sizeof(long); i++) {
 		x = (0x19660dULL * (u64)x + 0x3c6ef35fULL) & 0xffffffffUL;
 		bitmap[i] = x;
 	}
 	write_extent_buffer(eb, bitmap, 0, len);

 	for (i = 0; i < len * BITS_PER_BYTE; i++) {
 		int bit, bit1;

 		bit = !!test_bit(i, bitmap);
 		bit1 = !!extent_buffer_test_bit(eb, 0, i);
 		if (bit1 != bit) {
 			test_msg("Testing bit pattern failed\n");
 			return -EINVAL;
 		}

 		bit1 = !!extent_buffer_test_bit(eb, i / BITS_PER_BYTE,
 						i % BITS_PER_BYTE);
 		if (bit1 != bit) {
 			test_msg("Testing bit pattern with offset failed\n");
 			return -EINVAL;
 		}
 	}

 	return 0;
 }

 static int test_eb_bitmaps(void)
 {
 	unsigned long len = PAGE_SIZE * 4;
 	unsigned long *bitmap;
 	struct extent_buffer *eb;
 	int ret;

 	test_msg("Running extent buffer bitmap tests\n");

 	bitmap = kmalloc(len, GFP_KERNEL);
 	if (!bitmap) {
 		test_msg("Couldn't allocate test bitmap\n");
 		return -ENOMEM;
 	}

 	eb = __alloc_dummy_extent_buffer(NULL, 0, len);
 	if (!eb) {
 		test_msg("Couldn't allocate test extent buffer\n");
 		kfree(bitmap);
 		return -ENOMEM;
 	}

 	ret = __test_eb_bitmaps(bitmap, eb, len);
 	if (ret)
 		goto out;

 	/* Do it over again with an extent buffer which isn't page-aligned. */
 	free_extent_buffer(eb);
 	eb = __alloc_dummy_extent_buffer(NULL, PAGE_SIZE / 2, len);
 	if (!eb) {
 		test_msg("Couldn't allocate test extent buffer\n");
 		kfree(bitmap);
 		return -ENOMEM;
 	}

 	ret = __test_eb_bitmaps(bitmap, eb, len);
 out:
 	free_extent_buffer(eb);
 	kfree(bitmap);
 	return ret;
 }

 int btrfs_test_extent_io(void)
 {
 	int ret;

 	test_msg("Running extent I/O tests\n");

 	ret = test_find_delalloc();
 	if (ret)
 		goto out;

 	ret = test_eb_bitmaps();
 out:
 	test_msg("Extent I/O tests finished\n");
 	return ret;
 }
	/*
	* Copyright (C) 2013 Fusion IO. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public
	* License v2 as published by the Free Software Foundation.
	*
	* This program 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
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public
	* License along with this program; if not, write to the
	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	* Boston, MA 021110-1307, USA.
	*/

	#include <linux/pagemap.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/sizes.h>
	#include "btrfs-tests.h"
	#include "../extent_io.h"

	#define PROCESS_UNLOCK (1 << 0)
	#define PROCESS_RELEASE (1 << 1)
	#define PROCESS_TEST_LOCKED (1 << 2)

	static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
	unsigned long flags)
	{
	int ret;
	struct page *pages[16];
	unsigned long index = start >> PAGE_SHIFT;
	unsigned long end_index = end >> PAGE_SHIFT;
	unsigned long nr_pages = end_index - index + 1;
	int i;
	int count = 0;
	int loops = 0;

	while (nr_pages > 0) {
	ret = find_get_pages_contig(inode->i_mapping, index,
	min_t(unsigned long, nr_pages,
	ARRAY_SIZE(pages)), pages);
	for (i = 0; i < ret; i++) {
	if (flags & PROCESS_TEST_LOCKED &&
	!PageLocked(pages[i]))
	count++;
	if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
	unlock_page(pages[i]);
	put_page(pages[i]);
	if (flags & PROCESS_RELEASE)
	put_page(pages[i]);
	}
	nr_pages -= ret;
	index += ret;
	cond_resched();
	loops++;
	if (loops > 100000) {
	printk(KERN_ERR "stuck in a loop, start %Lu, end %Lu, nr_pages %lu, ret %d\n", start, end, nr_pages, ret);
	break;
	}
	}
	return count;
	}

	static int test_find_delalloc(void)
	{
	struct inode *inode;
	struct extent_io_tree tmp;
	struct page *page;
	struct page *locked_page = NULL;
	unsigned long index = 0;
	u64 total_dirty = SZ_256M;
	u64 max_bytes = SZ_128M;
	u64 start, end, test_start;
	u64 found;
	int ret = -EINVAL;

	test_msg("Running find delalloc tests\n");

	inode = btrfs_new_test_inode();
	if (!inode) {
	test_msg("Failed to allocate test inode\n");
	return -ENOMEM;
	}

	extent_io_tree_init(&tmp, &inode->i_data);

	/*
	* First go through and create and mark all of our pages dirty, we pin
	* everything to make sure our pages don't get evicted and screw up our
	* test.
	*/
	for (index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
	page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
	if (!page) {
	test_msg("Failed to allocate test page\n");
	ret = -ENOMEM;
	goto out;
	}
	SetPageDirty(page);
	if (index) {
	unlock_page(page);
	} else {
	get_page(page);
	locked_page = page;
	}
	}

	/* Test this scenario
	* \|--- delalloc ---\|
	* \|--- search ---\|
	*/
	set_extent_delalloc(&tmp, 0, 4095, NULL, GFP_KERNEL);
	start = 0;
	end = 0;
	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
	&end, max_bytes);
	if (!found) {
	test_msg("Should have found at least one delalloc\n");
	goto out_bits;
	}
	if (start != 0 \|\| end != 4095) {
	test_msg("Expected start 0 end 4095, got start %Lu end %Lu\n",
	start, end);
	goto out_bits;
	}
	unlock_extent(&tmp, start, end);
	unlock_page(locked_page);
	put_page(locked_page);

	/*
	* Test this scenario
	*
	* \|--- delalloc ---\|
	* \|--- search ---\|
	*/
	test_start = SZ_64M;
	locked_page = find_lock_page(inode->i_mapping,
	test_start >> PAGE_SHIFT);
	if (!locked_page) {
	test_msg("Couldn't find the locked page\n");
	goto out_bits;
	}
	set_extent_delalloc(&tmp, 4096, max_bytes - 1, NULL, GFP_KERNEL);
	start = test_start;
	end = 0;
	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
	&end, max_bytes);
	if (!found) {
	test_msg("Couldn't find delalloc in our range\n");
	goto out_bits;
	}
	if (start != test_start \|\| end != max_bytes - 1) {
	test_msg("Expected start %Lu end %Lu, got start %Lu, end "
	"%Lu\n", test_start, max_bytes - 1, start, end);
	goto out_bits;
	}
	if (process_page_range(inode, start, end,
	PROCESS_TEST_LOCKED \| PROCESS_UNLOCK)) {
	test_msg("There were unlocked pages in the range\n");
	goto out_bits;
	}
	unlock_extent(&tmp, start, end);
	/* locked_page was unlocked above */
	put_page(locked_page);

	/*
	* Test this scenario
	* \|--- delalloc ---\|
	* \|--- search ---\|
	*/
	test_start = max_bytes + 4096;
	locked_page = find_lock_page(inode->i_mapping, test_start >>
	PAGE_SHIFT);
	if (!locked_page) {
	test_msg("Could'nt find the locked page\n");
	goto out_bits;
	}
	start = test_start;
	end = 0;
	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
	&end, max_bytes);
	if (found) {
	test_msg("Found range when we shouldn't have\n");
	goto out_bits;
	}
	if (end != (u64)-1) {
	test_msg("Did not return the proper end offset\n");
	goto out_bits;
	}

	/*
	* Test this scenario
	* [------- delalloc -------\|
	* [max_bytes]\|-- search--\|
	*
	* We are re-using our test_start from above since it works out well.
	*/
	set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, NULL, GFP_KERNEL);
	start = test_start;
	end = 0;
	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
	&end, max_bytes);
	if (!found) {
	test_msg("Didn't find our range\n");
	goto out_bits;
	}
	if (start != test_start \|\| end != total_dirty - 1) {
	test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
	test_start, total_dirty - 1, start, end);
	goto out_bits;
	}
	if (process_page_range(inode, start, end,
	PROCESS_TEST_LOCKED \| PROCESS_UNLOCK)) {
	test_msg("Pages in range were not all locked\n");
	goto out_bits;
	}
	unlock_extent(&tmp, start, end);

	/*
	* Now to test where we run into a page that is no longer dirty in the
	* range we want to find.
	*/
	page = find_get_page(inode->i_mapping,
	(max_bytes + SZ_1M) >> PAGE_SHIFT);
	if (!page) {
	test_msg("Couldn't find our page\n");
	goto out_bits;
	}
	ClearPageDirty(page);
	put_page(page);

	/* We unlocked it in the previous test */
	lock_page(locked_page);
	start = test_start;
	end = 0;
	/*
	* Currently if we fail to find dirty pages in the delalloc range we
	* will adjust max_bytes down to PAGE_CACHE_SIZE and then re-search. If
	* this changes at any point in the future we will need to fix this
	* tests expected behavior.
	*/
	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
	&end, max_bytes);
	if (!found) {
	test_msg("Didn't find our range\n");
	goto out_bits;
	}
	if (start != test_start && end != test_start + PAGE_SIZE - 1) {
	test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
	test_start, test_start + PAGE_SIZE - 1, start,
	end);
	goto out_bits;
	}
	if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED \|
	PROCESS_UNLOCK)) {
	test_msg("Pages in range were not all locked\n");
	goto out_bits;
	}
	ret = 0;
	out_bits:
	clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_KERNEL);
	out:
	if (locked_page)
	put_page(locked_page);
	process_page_range(inode, 0, total_dirty - 1,
	PROCESS_UNLOCK \| PROCESS_RELEASE);
	iput(inode);
	return ret;
	}

	static int __test_eb_bitmaps(unsigned long bitmap, struct extent_buffer eb,
	unsigned long len)
	{
	unsigned long i, x;

	memset(bitmap, 0, len);
	memset_extent_buffer(eb, 0, 0, len);
	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
	test_msg("Bitmap was not zeroed\n");
	return -EINVAL;
	}

	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
	test_msg("Setting all bits failed\n");
	return -EINVAL;
	}

	bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
	extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
	test_msg("Clearing all bits failed\n");
	return -EINVAL;
	}

	bitmap_set(bitmap, (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
	sizeof(long) * BITS_PER_BYTE);
	extent_buffer_bitmap_set(eb, PAGE_SIZE - sizeof(long) / 2, 0,
	sizeof(long) * BITS_PER_BYTE);
	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
	test_msg("Setting straddling pages failed\n");
	return -EINVAL;
	}

	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
	bitmap_clear(bitmap,
	(PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
	sizeof(long) * BITS_PER_BYTE);
	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
	extent_buffer_bitmap_clear(eb, PAGE_SIZE - sizeof(long) / 2, 0,
	sizeof(long) * BITS_PER_BYTE);
	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
	test_msg("Clearing straddling pages failed\n");
	return -EINVAL;
	}

	/*
	* Generate a wonky pseudo-random bit pattern for the sake of not using
	* something repetitive that could miss some hypothetical off-by-n bug.
	*/
	x = 0;
	for (i = 0; i < len / sizeof(long); i++) {
	x = (0x19660dULL * (u64)x + 0x3c6ef35fULL) & 0xffffffffUL;
	bitmap[i] = x;
	}
	write_extent_buffer(eb, bitmap, 0, len);

	for (i = 0; i < len * BITS_PER_BYTE; i++) {
	int bit, bit1;

	bit = !!test_bit(i, bitmap);
	bit1 = !!extent_buffer_test_bit(eb, 0, i);
	if (bit1 != bit) {
	test_msg("Testing bit pattern failed\n");
	return -EINVAL;
	}

	bit1 = !!extent_buffer_test_bit(eb, i / BITS_PER_BYTE,
	i % BITS_PER_BYTE);
	if (bit1 != bit) {
	test_msg("Testing bit pattern with offset failed\n");
	return -EINVAL;
	}
	}

	return 0;
	}

	static int test_eb_bitmaps(void)
	{
	unsigned long len = PAGE_SIZE * 4;
	unsigned long *bitmap;
	struct extent_buffer *eb;
	int ret;

	test_msg("Running extent buffer bitmap tests\n");

	bitmap = kmalloc(len, GFP_KERNEL);
	if (!bitmap) {
	test_msg("Couldn't allocate test bitmap\n");
	return -ENOMEM;
	}

	eb = __alloc_dummy_extent_buffer(NULL, 0, len);
	if (!eb) {
	test_msg("Couldn't allocate test extent buffer\n");
	kfree(bitmap);
	return -ENOMEM;
	}

	ret = __test_eb_bitmaps(bitmap, eb, len);
	if (ret)
	goto out;

	/* Do it over again with an extent buffer which isn't page-aligned. */
	free_extent_buffer(eb);
	eb = __alloc_dummy_extent_buffer(NULL, PAGE_SIZE / 2, len);
	if (!eb) {
	test_msg("Couldn't allocate test extent buffer\n");
	kfree(bitmap);
	return -ENOMEM;
	}

	ret = __test_eb_bitmaps(bitmap, eb, len);
	out:
	free_extent_buffer(eb);
	kfree(bitmap);
	return ret;
	}

	int btrfs_test_extent_io(void)
	{
	int ret;

	test_msg("Running extent I/O tests\n");

	ret = test_find_delalloc();
	if (ret)
	goto out;

	ret = test_eb_bitmaps();
	out:
	test_msg("Extent I/O tests finished\n");
	return ret;
	}