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linux/fs/btrfs/tests/free-space-tests.c
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00

871 lines
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/*
* 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/slab.h>
#include "btrfs-tests.h"
#include "../ctree.h"
#include "../disk-io.h"
#include "../free-space-cache.h"
#define BITS_PER_BITMAP (PAGE_SIZE * 8)
/*
* This test just does basic sanity checking, making sure we can add an exten
* entry and remove space from either end and the middle, and make sure we can
* remove space that covers adjacent extent entries.
*/
static int test_extents(struct btrfs_block_group_cache *cache)
{
int ret = 0;
test_msg("Running extent only tests\n");
/* First just make sure we can remove an entire entry */
ret = btrfs_add_free_space(cache, 0, SZ_4M);
if (ret) {
test_msg("Error adding initial extents %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 0, SZ_4M);
if (ret) {
test_msg("Error removing extent %d\n", ret);
return ret;
}
if (test_check_exists(cache, 0, SZ_4M)) {
test_msg("Full remove left some lingering space\n");
return -1;
}
/* Ok edge and middle cases now */
ret = btrfs_add_free_space(cache, 0, SZ_4M);
if (ret) {
test_msg("Error adding half extent %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_1M);
if (ret) {
test_msg("Error removing tail end %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 0, SZ_1M);
if (ret) {
test_msg("Error removing front end %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, SZ_2M, 4096);
if (ret) {
test_msg("Error removing middle piece %d\n", ret);
return ret;
}
if (test_check_exists(cache, 0, SZ_1M)) {
test_msg("Still have space at the front\n");
return -1;
}
if (test_check_exists(cache, SZ_2M, 4096)) {
test_msg("Still have space in the middle\n");
return -1;
}
if (test_check_exists(cache, 3 * SZ_1M, SZ_1M)) {
test_msg("Still have space at the end\n");
return -1;
}
/* Cleanup */
__btrfs_remove_free_space_cache(cache->free_space_ctl);
return 0;
}
static int test_bitmaps(struct btrfs_block_group_cache *cache)
{
u64 next_bitmap_offset;
int ret;
test_msg("Running bitmap only tests\n");
ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
if (ret) {
test_msg("Couldn't create a bitmap entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 0, SZ_4M);
if (ret) {
test_msg("Error removing bitmap full range %d\n", ret);
return ret;
}
if (test_check_exists(cache, 0, SZ_4M)) {
test_msg("Left some space in bitmap\n");
return -1;
}
ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
if (ret) {
test_msg("Couldn't add to our bitmap entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, SZ_1M, SZ_2M);
if (ret) {
test_msg("Couldn't remove middle chunk %d\n", ret);
return ret;
}
/*
* The first bitmap we have starts at offset 0 so the next one is just
* at the end of the first bitmap.
*/
next_bitmap_offset = (u64)(BITS_PER_BITMAP * 4096);
/* Test a bit straddling two bitmaps */
ret = test_add_free_space_entry(cache, next_bitmap_offset - SZ_2M,
SZ_4M, 1);
if (ret) {
test_msg("Couldn't add space that straddles two bitmaps %d\n",
ret);
return ret;
}
ret = btrfs_remove_free_space(cache, next_bitmap_offset - SZ_1M, SZ_2M);
if (ret) {
test_msg("Couldn't remove overlapping space %d\n", ret);
return ret;
}
if (test_check_exists(cache, next_bitmap_offset - SZ_1M, SZ_2M)) {
test_msg("Left some space when removing overlapping\n");
return -1;
}
__btrfs_remove_free_space_cache(cache->free_space_ctl);
return 0;
}
/* This is the high grade jackassery */
static int test_bitmaps_and_extents(struct btrfs_block_group_cache *cache)
{
u64 bitmap_offset = (u64)(BITS_PER_BITMAP * 4096);
int ret;
test_msg("Running bitmap and extent tests\n");
/*
* First let's do something simple, an extent at the same offset as the
* bitmap, but the free space completely in the extent and then
* completely in the bitmap.
*/
ret = test_add_free_space_entry(cache, SZ_4M, SZ_1M, 1);
if (ret) {
test_msg("Couldn't create bitmap entry %d\n", ret);
return ret;
}
ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
if (ret) {
test_msg("Couldn't add extent entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 0, SZ_1M);
if (ret) {
test_msg("Couldn't remove extent entry %d\n", ret);
return ret;
}
if (test_check_exists(cache, 0, SZ_1M)) {
test_msg("Left remnants after our remove\n");
return -1;
}
/* Now to add back the extent entry and remove from the bitmap */
ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
if (ret) {
test_msg("Couldn't re-add extent entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, SZ_4M, SZ_1M);
if (ret) {
test_msg("Couldn't remove from bitmap %d\n", ret);
return ret;
}
if (test_check_exists(cache, SZ_4M, SZ_1M)) {
test_msg("Left remnants in the bitmap\n");
return -1;
}
/*
* Ok so a little more evil, extent entry and bitmap at the same offset,
* removing an overlapping chunk.
*/
ret = test_add_free_space_entry(cache, SZ_1M, SZ_4M, 1);
if (ret) {
test_msg("Couldn't add to a bitmap %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, SZ_512K, 3 * SZ_1M);
if (ret) {
test_msg("Couldn't remove overlapping space %d\n", ret);
return ret;
}
if (test_check_exists(cache, SZ_512K, 3 * SZ_1M)) {
test_msg("Left over pieces after removing overlapping\n");
return -1;
}
__btrfs_remove_free_space_cache(cache->free_space_ctl);
/* Now with the extent entry offset into the bitmap */
ret = test_add_free_space_entry(cache, SZ_4M, SZ_4M, 1);
if (ret) {
test_msg("Couldn't add space to the bitmap %d\n", ret);
return ret;
}
ret = test_add_free_space_entry(cache, SZ_2M, SZ_2M, 0);
if (ret) {
test_msg("Couldn't add extent to the cache %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_4M);
if (ret) {
test_msg("Problem removing overlapping space %d\n", ret);
return ret;
}
if (test_check_exists(cache, 3 * SZ_1M, SZ_4M)) {
test_msg("Left something behind when removing space");
return -1;
}
/*
* This has blown up in the past, the extent entry starts before the
* bitmap entry, but we're trying to remove an offset that falls
* completely within the bitmap range and is in both the extent entry
* and the bitmap entry, looks like this
*
* [ extent ]
* [ bitmap ]
* [ del ]
*/
__btrfs_remove_free_space_cache(cache->free_space_ctl);
ret = test_add_free_space_entry(cache, bitmap_offset + SZ_4M, SZ_4M, 1);
if (ret) {
test_msg("Couldn't add bitmap %d\n", ret);
return ret;
}
ret = test_add_free_space_entry(cache, bitmap_offset - SZ_1M,
5 * SZ_1M, 0);
if (ret) {
test_msg("Couldn't add extent entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, bitmap_offset + SZ_1M, 5 * SZ_1M);
if (ret) {
test_msg("Failed to free our space %d\n", ret);
return ret;
}
if (test_check_exists(cache, bitmap_offset + SZ_1M, 5 * SZ_1M)) {
test_msg("Left stuff over\n");
return -1;
}
__btrfs_remove_free_space_cache(cache->free_space_ctl);
/*
* This blew up before, we have part of the free space in a bitmap and
* then the entirety of the rest of the space in an extent. This used
* to return -EAGAIN back from btrfs_remove_extent, make sure this
* doesn't happen.
*/
ret = test_add_free_space_entry(cache, SZ_1M, SZ_2M, 1);
if (ret) {
test_msg("Couldn't add bitmap entry %d\n", ret);
return ret;
}
ret = test_add_free_space_entry(cache, 3 * SZ_1M, SZ_1M, 0);
if (ret) {
test_msg("Couldn't add extent entry %d\n", ret);
return ret;
}
ret = btrfs_remove_free_space(cache, SZ_1M, 3 * SZ_1M);
if (ret) {
test_msg("Error removing bitmap and extent overlapping %d\n", ret);
return ret;
}
__btrfs_remove_free_space_cache(cache->free_space_ctl);
return 0;
}
/* Used by test_steal_space_from_bitmap_to_extent(). */
static bool test_use_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
return ctl->free_extents > 0;
}
/* Used by test_steal_space_from_bitmap_to_extent(). */
static int
check_num_extents_and_bitmaps(const struct btrfs_block_group_cache *cache,
const int num_extents,
const int num_bitmaps)
{
if (cache->free_space_ctl->free_extents != num_extents) {
test_msg("Incorrect # of extent entries in the cache: %d, expected %d\n",
cache->free_space_ctl->free_extents, num_extents);
return -EINVAL;
}
if (cache->free_space_ctl->total_bitmaps != num_bitmaps) {
test_msg("Incorrect # of extent entries in the cache: %d, expected %d\n",
cache->free_space_ctl->total_bitmaps, num_bitmaps);
return -EINVAL;
}
return 0;
}
/* Used by test_steal_space_from_bitmap_to_extent(). */
static int check_cache_empty(struct btrfs_block_group_cache *cache)
{
u64 offset;
u64 max_extent_size;
/*
* Now lets confirm that there's absolutely no free space left to
* allocate.
*/
if (cache->free_space_ctl->free_space != 0) {
test_msg("Cache free space is not 0\n");
return -EINVAL;
}
/* And any allocation request, no matter how small, should fail now. */
offset = btrfs_find_space_for_alloc(cache, 0, 4096, 0,
&max_extent_size);
if (offset != 0) {
test_msg("Space allocation did not fail, returned offset: %llu",
offset);
return -EINVAL;
}
/* And no extent nor bitmap entries in the cache anymore. */
return check_num_extents_and_bitmaps(cache, 0, 0);
}
/*
* Before we were able to steal free space from a bitmap entry to an extent
* entry, we could end up with 2 entries representing a contiguous free space.
* One would be an extent entry and the other a bitmap entry. Since in order
* to allocate space to a caller we use only 1 entry, we couldn't return that
* whole range to the caller if it was requested. This forced the caller to
* either assume ENOSPC or perform several smaller space allocations, which
* wasn't optimal as they could be spread all over the block group while under
* concurrency (extra overhead and fragmentation).
*
* This stealing approach is benefical, since we always prefer to allocate from
* extent entries, both for clustered and non-clustered allocation requests.
*/
static int
test_steal_space_from_bitmap_to_extent(struct btrfs_block_group_cache *cache)
{
int ret;
u64 offset;
u64 max_extent_size;
const struct btrfs_free_space_op test_free_space_ops = {
.recalc_thresholds = cache->free_space_ctl->op->recalc_thresholds,
.use_bitmap = test_use_bitmap,
};
const struct btrfs_free_space_op *orig_free_space_ops;
test_msg("Running space stealing from bitmap to extent\n");
/*
* For this test, we want to ensure we end up with an extent entry
* immediately adjacent to a bitmap entry, where the bitmap starts
* at an offset where the extent entry ends. We keep adding and
* removing free space to reach into this state, but to get there
* we need to reach a point where marking new free space doesn't
* result in adding new extent entries or merging the new space
* with existing extent entries - the space ends up being marked
* in an existing bitmap that covers the new free space range.
*
* To get there, we need to reach the threshold defined set at
* cache->free_space_ctl->extents_thresh, which currently is
* 256 extents on a x86_64 system at least, and a few other
* conditions (check free_space_cache.c). Instead of making the
* test much longer and complicated, use a "use_bitmap" operation
* that forces use of bitmaps as soon as we have at least 1
* extent entry.
*/
orig_free_space_ops = cache->free_space_ctl->op;
cache->free_space_ctl->op = &test_free_space_ops;
/*
* Extent entry covering free space range [128Mb - 256Kb, 128Mb - 128Kb[
*/
ret = test_add_free_space_entry(cache, SZ_128M - SZ_256K, SZ_128K, 0);
if (ret) {
test_msg("Couldn't add extent entry %d\n", ret);
return ret;
}
/* Bitmap entry covering free space range [128Mb + 512Kb, 256Mb[ */
ret = test_add_free_space_entry(cache, SZ_128M + SZ_512K,
SZ_128M - SZ_512K, 1);
if (ret) {
test_msg("Couldn't add bitmap entry %d\n", ret);
return ret;
}
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* Now make only the first 256Kb of the bitmap marked as free, so that
* we end up with only the following ranges marked as free space:
*
* [128Mb - 256Kb, 128Mb - 128Kb[
* [128Mb + 512Kb, 128Mb + 768Kb[
*/
ret = btrfs_remove_free_space(cache,
SZ_128M + 768 * SZ_1K,
SZ_128M - 768 * SZ_1K);
if (ret) {
test_msg("Failed to free part of bitmap space %d\n", ret);
return ret;
}
/* Confirm that only those 2 ranges are marked as free. */
if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_128K)) {
test_msg("Free space range missing\n");
return -ENOENT;
}
if (!test_check_exists(cache, SZ_128M + SZ_512K, SZ_256K)) {
test_msg("Free space range missing\n");
return -ENOENT;
}
/*
* Confirm that the bitmap range [128Mb + 768Kb, 256Mb[ isn't marked
* as free anymore.
*/
if (test_check_exists(cache, SZ_128M + 768 * SZ_1K,
SZ_128M - 768 * SZ_1K)) {
test_msg("Bitmap region not removed from space cache\n");
return -EINVAL;
}
/*
* Confirm that the region [128Mb + 256Kb, 128Mb + 512Kb[, which is
* covered by the bitmap, isn't marked as free.
*/
if (test_check_exists(cache, SZ_128M + SZ_256K, SZ_256K)) {
test_msg("Invalid bitmap region marked as free\n");
return -EINVAL;
}
/*
* Confirm that the region [128Mb, 128Mb + 256Kb[, which is covered
* by the bitmap too, isn't marked as free either.
*/
if (test_check_exists(cache, SZ_128M, SZ_256K)) {
test_msg("Invalid bitmap region marked as free\n");
return -EINVAL;
}
/*
* Now lets mark the region [128Mb, 128Mb + 512Kb[ as free too. But,
* lets make sure the free space cache marks it as free in the bitmap,
* and doesn't insert a new extent entry to represent this region.
*/
ret = btrfs_add_free_space(cache, SZ_128M, SZ_512K);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/* Confirm the region is marked as free. */
if (!test_check_exists(cache, SZ_128M, SZ_512K)) {
test_msg("Bitmap region not marked as free\n");
return -ENOENT;
}
/*
* Confirm that no new extent entries or bitmap entries were added to
* the cache after adding that free space region.
*/
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* Now lets add a small free space region to the right of the previous
* one, which is not contiguous with it and is part of the bitmap too.
* The goal is to test that the bitmap entry space stealing doesn't
* steal this space region.
*/
ret = btrfs_add_free_space(cache, SZ_128M + SZ_16M, 4096);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/*
* Confirm that no new extent entries or bitmap entries were added to
* the cache after adding that free space region.
*/
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* Now mark the region [128Mb - 128Kb, 128Mb[ as free too. This will
* expand the range covered by the existing extent entry that represents
* the free space [128Mb - 256Kb, 128Mb - 128Kb[.
*/
ret = btrfs_add_free_space(cache, SZ_128M - SZ_128K, SZ_128K);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/* Confirm the region is marked as free. */
if (!test_check_exists(cache, SZ_128M - SZ_128K, SZ_128K)) {
test_msg("Extent region not marked as free\n");
return -ENOENT;
}
/*
* Confirm that our extent entry didn't stole all free space from the
* bitmap, because of the small 4Kb free space region.
*/
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* So now we have the range [128Mb - 256Kb, 128Mb + 768Kb[ as free
* space. Without stealing bitmap free space into extent entry space,
* we would have all this free space represented by 2 entries in the
* cache:
*
* extent entry covering range: [128Mb - 256Kb, 128Mb[
* bitmap entry covering range: [128Mb, 128Mb + 768Kb[
*
* Attempting to allocate the whole free space (1Mb) would fail, because
* we can't allocate from multiple entries.
* With the bitmap free space stealing, we get a single extent entry
* that represents the 1Mb free space, and therefore we're able to
* allocate the whole free space at once.
*/
if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_1M)) {
test_msg("Expected region not marked as free\n");
return -ENOENT;
}
if (cache->free_space_ctl->free_space != (SZ_1M + 4096)) {
test_msg("Cache free space is not 1Mb + 4Kb\n");
return -EINVAL;
}
offset = btrfs_find_space_for_alloc(cache,
0, SZ_1M, 0,
&max_extent_size);
if (offset != (SZ_128M - SZ_256K)) {
test_msg("Failed to allocate 1Mb from space cache, returned offset is: %llu\n",
offset);
return -EINVAL;
}
/* All that remains is a 4Kb free space region in a bitmap. Confirm. */
ret = check_num_extents_and_bitmaps(cache, 1, 1);
if (ret)
return ret;
if (cache->free_space_ctl->free_space != 4096) {
test_msg("Cache free space is not 4Kb\n");
return -EINVAL;
}
offset = btrfs_find_space_for_alloc(cache,
0, 4096, 0,
&max_extent_size);
if (offset != (SZ_128M + SZ_16M)) {
test_msg("Failed to allocate 4Kb from space cache, returned offset is: %llu\n",
offset);
return -EINVAL;
}
ret = check_cache_empty(cache);
if (ret)
return ret;
__btrfs_remove_free_space_cache(cache->free_space_ctl);
/*
* Now test a similar scenario, but where our extent entry is located
* to the right of the bitmap entry, so that we can check that stealing
* space from a bitmap to the front of an extent entry works.
*/
/*
* Extent entry covering free space range [128Mb + 128Kb, 128Mb + 256Kb[
*/
ret = test_add_free_space_entry(cache, SZ_128M + SZ_128K, SZ_128K, 0);
if (ret) {
test_msg("Couldn't add extent entry %d\n", ret);
return ret;
}
/* Bitmap entry covering free space range [0, 128Mb - 512Kb[ */
ret = test_add_free_space_entry(cache, 0, SZ_128M - SZ_512K, 1);
if (ret) {
test_msg("Couldn't add bitmap entry %d\n", ret);
return ret;
}
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* Now make only the last 256Kb of the bitmap marked as free, so that
* we end up with only the following ranges marked as free space:
*
* [128Mb + 128b, 128Mb + 256Kb[
* [128Mb - 768Kb, 128Mb - 512Kb[
*/
ret = btrfs_remove_free_space(cache, 0, SZ_128M - 768 * SZ_1K);
if (ret) {
test_msg("Failed to free part of bitmap space %d\n", ret);
return ret;
}
/* Confirm that only those 2 ranges are marked as free. */
if (!test_check_exists(cache, SZ_128M + SZ_128K, SZ_128K)) {
test_msg("Free space range missing\n");
return -ENOENT;
}
if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_256K)) {
test_msg("Free space range missing\n");
return -ENOENT;
}
/*
* Confirm that the bitmap range [0, 128Mb - 768Kb[ isn't marked
* as free anymore.
*/
if (test_check_exists(cache, 0, SZ_128M - 768 * SZ_1K)) {
test_msg("Bitmap region not removed from space cache\n");
return -EINVAL;
}
/*
* Confirm that the region [128Mb - 512Kb, 128Mb[, which is
* covered by the bitmap, isn't marked as free.
*/
if (test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
test_msg("Invalid bitmap region marked as free\n");
return -EINVAL;
}
/*
* Now lets mark the region [128Mb - 512Kb, 128Mb[ as free too. But,
* lets make sure the free space cache marks it as free in the bitmap,
* and doesn't insert a new extent entry to represent this region.
*/
ret = btrfs_add_free_space(cache, SZ_128M - SZ_512K, SZ_512K);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/* Confirm the region is marked as free. */
if (!test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
test_msg("Bitmap region not marked as free\n");
return -ENOENT;
}
/*
* Confirm that no new extent entries or bitmap entries were added to
* the cache after adding that free space region.
*/
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* Now lets add a small free space region to the left of the previous
* one, which is not contiguous with it and is part of the bitmap too.
* The goal is to test that the bitmap entry space stealing doesn't
* steal this space region.
*/
ret = btrfs_add_free_space(cache, SZ_32M, 8192);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/*
* Now mark the region [128Mb, 128Mb + 128Kb[ as free too. This will
* expand the range covered by the existing extent entry that represents
* the free space [128Mb + 128Kb, 128Mb + 256Kb[.
*/
ret = btrfs_add_free_space(cache, SZ_128M, SZ_128K);
if (ret) {
test_msg("Error adding free space: %d\n", ret);
return ret;
}
/* Confirm the region is marked as free. */
if (!test_check_exists(cache, SZ_128M, SZ_128K)) {
test_msg("Extent region not marked as free\n");
return -ENOENT;
}
/*
* Confirm that our extent entry didn't stole all free space from the
* bitmap, because of the small 8Kb free space region.
*/
ret = check_num_extents_and_bitmaps(cache, 2, 1);
if (ret)
return ret;
/*
* So now we have the range [128Mb - 768Kb, 128Mb + 256Kb[ as free
* space. Without stealing bitmap free space into extent entry space,
* we would have all this free space represented by 2 entries in the
* cache:
*
* extent entry covering range: [128Mb, 128Mb + 256Kb[
* bitmap entry covering range: [128Mb - 768Kb, 128Mb[
*
* Attempting to allocate the whole free space (1Mb) would fail, because
* we can't allocate from multiple entries.
* With the bitmap free space stealing, we get a single extent entry
* that represents the 1Mb free space, and therefore we're able to
* allocate the whole free space at once.
*/
if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_1M)) {
test_msg("Expected region not marked as free\n");
return -ENOENT;
}
if (cache->free_space_ctl->free_space != (SZ_1M + 8192)) {
test_msg("Cache free space is not 1Mb + 8Kb\n");
return -EINVAL;
}
offset = btrfs_find_space_for_alloc(cache, 0, SZ_1M, 0,
&max_extent_size);
if (offset != (SZ_128M - 768 * SZ_1K)) {
test_msg("Failed to allocate 1Mb from space cache, returned offset is: %llu\n",
offset);
return -EINVAL;
}
/* All that remains is a 8Kb free space region in a bitmap. Confirm. */
ret = check_num_extents_and_bitmaps(cache, 1, 1);
if (ret)
return ret;
if (cache->free_space_ctl->free_space != 8192) {
test_msg("Cache free space is not 8Kb\n");
return -EINVAL;
}
offset = btrfs_find_space_for_alloc(cache,
0, 8192, 0,
&max_extent_size);
if (offset != SZ_32M) {
test_msg("Failed to allocate 8Kb from space cache, returned offset is: %llu\n",
offset);
return -EINVAL;
}
ret = check_cache_empty(cache);
if (ret)
return ret;
cache->free_space_ctl->op = orig_free_space_ops;
__btrfs_remove_free_space_cache(cache->free_space_ctl);
return 0;
}
int btrfs_test_free_space_cache(void)
{
struct btrfs_block_group_cache *cache;
struct btrfs_root *root = NULL;
int ret = -ENOMEM;
test_msg("Running btrfs free space cache tests\n");
cache = btrfs_alloc_dummy_block_group(1024 * 1024 * 1024);
if (!cache) {
test_msg("Couldn't run the tests\n");
return 0;
}
root = btrfs_alloc_dummy_root();
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out;
}
root->fs_info = btrfs_alloc_dummy_fs_info();
if (!root->fs_info)
goto out;
root->fs_info->extent_root = root;
cache->fs_info = root->fs_info;
ret = test_extents(cache);
if (ret)
goto out;
ret = test_bitmaps(cache);
if (ret)
goto out;
ret = test_bitmaps_and_extents(cache);
if (ret)
goto out;
ret = test_steal_space_from_bitmap_to_extent(cache);
out:
btrfs_free_dummy_block_group(cache);
btrfs_free_dummy_root(root);
test_msg("Free space cache tests finished\n");
return ret;
}
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