From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- fs/btrfs/tests/free-space-tests.c | 909 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 909 insertions(+) create mode 100644 fs/btrfs/tests/free-space-tests.c (limited to 'fs/btrfs/tests/free-space-tests.c') diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c new file mode 100644 index 000000000..2299bfde3 --- /dev/null +++ b/fs/btrfs/tests/free-space-tests.c @@ -0,0 +1,909 @@ +/* + * 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 +#include "btrfs-tests.h" +#include "../ctree.h" +#include "../free-space-cache.h" + +#define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) +static struct btrfs_block_group_cache *init_test_block_group(void) +{ + struct btrfs_block_group_cache *cache; + + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) + return NULL; + cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl), + GFP_NOFS); + if (!cache->free_space_ctl) { + kfree(cache); + return NULL; + } + + cache->key.objectid = 0; + cache->key.offset = 1024 * 1024 * 1024; + cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; + cache->sectorsize = 4096; + cache->full_stripe_len = 4096; + + spin_lock_init(&cache->lock); + INIT_LIST_HEAD(&cache->list); + INIT_LIST_HEAD(&cache->cluster_list); + INIT_LIST_HEAD(&cache->bg_list); + + btrfs_init_free_space_ctl(cache); + + return cache; +} + +/* + * 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, 4 * 1024 * 1024); + if (ret) { + test_msg("Error adding initial extents %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 0, 4 * 1024 * 1024); + if (ret) { + test_msg("Error removing extent %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 0, 4 * 1024 * 1024)) { + test_msg("Full remove left some lingering space\n"); + return -1; + } + + /* Ok edge and middle cases now */ + ret = btrfs_add_free_space(cache, 0, 4 * 1024 * 1024); + if (ret) { + test_msg("Error adding half extent %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 3 * 1024 * 1024, 1 * 1024 * 1024); + if (ret) { + test_msg("Error removing tail end %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 0, 1 * 1024 * 1024); + if (ret) { + test_msg("Error removing front end %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 2 * 1024 * 1024, 4096); + if (ret) { + test_msg("Error removing middle piece %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 0, 1 * 1024 * 1024)) { + test_msg("Still have space at the front\n"); + return -1; + } + + if (test_check_exists(cache, 2 * 1024 * 1024, 4096)) { + test_msg("Still have space in the middle\n"); + return -1; + } + + if (test_check_exists(cache, 3 * 1024 * 1024, 1 * 1024 * 1024)) { + 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, 4 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't create a bitmap entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 0, 4 * 1024 * 1024); + if (ret) { + test_msg("Error removing bitmap full range %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 0, 4 * 1024 * 1024)) { + test_msg("Left some space in bitmap\n"); + return -1; + } + + ret = test_add_free_space_entry(cache, 0, 4 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't add to our bitmap entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 1 * 1024 * 1024, 2 * 1024 * 1024); + 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 - + (2 * 1024 * 1024), 4 * 1024 * 1024, 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 - + (1 * 1024 * 1024), 2 * 1024 * 1024); + if (ret) { + test_msg("Couldn't remove overlapping space %d\n", ret); + return ret; + } + + if (test_check_exists(cache, next_bitmap_offset - (1 * 1024 * 1024), + 2 * 1024 * 1024)) { + 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, 4 * 1024 * 1024, 1 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't create bitmap entry %d\n", ret); + return ret; + } + + ret = test_add_free_space_entry(cache, 0, 1 * 1024 * 1024, 0); + if (ret) { + test_msg("Couldn't add extent entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 0, 1 * 1024 * 1024); + if (ret) { + test_msg("Couldn't remove extent entry %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 0, 1 * 1024 * 1024)) { + 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, 1 * 1024 * 1024, 0); + if (ret) { + test_msg("Couldn't re-add extent entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 4 * 1024 * 1024, 1 * 1024 * 1024); + if (ret) { + test_msg("Couldn't remove from bitmap %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 4 * 1024 * 1024, 1 * 1024 * 1024)) { + 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, 1 * 1024 * 1024, 4 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't add to a bitmap %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 512 * 1024, 3 * 1024 * 1024); + if (ret) { + test_msg("Couldn't remove overlapping space %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 512 * 1024, 3 * 1024 * 1024)) { + 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, 4 * 1024 * 1024, 4 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't add space to the bitmap %d\n", ret); + return ret; + } + + ret = test_add_free_space_entry(cache, 2 * 1024 * 1024, 2 * 1024 * 1024, 0); + if (ret) { + test_msg("Couldn't add extent to the cache %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 3 * 1024 * 1024, 4 * 1024 * 1024); + if (ret) { + test_msg("Problem removing overlapping space %d\n", ret); + return ret; + } + + if (test_check_exists(cache, 3 * 1024 * 1024, 4 * 1024 * 1024)) { + 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 + 4 * 1024 * 1024, + 4 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't add bitmap %d\n", ret); + return ret; + } + + ret = test_add_free_space_entry(cache, bitmap_offset - 1 * 1024 * 1024, + 5 * 1024 * 1024, 0); + if (ret) { + test_msg("Couldn't add extent entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, bitmap_offset + 1 * 1024 * 1024, + 5 * 1024 * 1024); + if (ret) { + test_msg("Failed to free our space %d\n", ret); + return ret; + } + + if (test_check_exists(cache, bitmap_offset + 1 * 1024 * 1024, + 5 * 1024 * 1024)) { + 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, 1 * 1024 * 1024, 2 * 1024 * 1024, 1); + if (ret) { + test_msg("Couldn't add bitmap entry %d\n", ret); + return ret; + } + + ret = test_add_free_space_entry(cache, 3 * 1024 * 1024, 1 * 1024 * 1024, 0); + if (ret) { + test_msg("Couldn't add extent entry %d\n", ret); + return ret; + } + + ret = btrfs_remove_free_space(cache, 1 * 1024 * 1024, 3 * 1024 * 1024); + 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; + + bool (*use_bitmap_op)(struct btrfs_free_space_ctl *, + struct btrfs_free_space *); + + 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. + */ + use_bitmap_op = cache->free_space_ctl->op->use_bitmap; + cache->free_space_ctl->op->use_bitmap = test_use_bitmap; + + /* + * Extent entry covering free space range [128Mb - 256Kb, 128Mb - 128Kb[ + */ + ret = test_add_free_space_entry(cache, 128 * 1024 * 1024 - 256 * 1024, + 128 * 1024, 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, 128 * 1024 * 1024 + 512 * 1024, + 128 * 1024 * 1024 - 512 * 1024, 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, + 128 * 1024 * 1024 + 768 * 1024, + 128 * 1024 * 1024 - 768 * 1024); + 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, 128 * 1024 * 1024 - 256 * 1024, + 128 * 1024)) { + test_msg("Free space range missing\n"); + return -ENOENT; + } + if (!test_check_exists(cache, 128 * 1024 * 1024 + 512 * 1024, + 256 * 1024)) { + 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, 128 * 1024 * 1024 + 768 * 1024, + 128 * 1024 * 1024 - 768 * 1024)) { + 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, 128 * 1024 * 1024 + 256 * 1024, + 256 * 1024)) { + 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, 128 * 1024 * 1024, + 256 * 1024)) { + 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, 128 * 1024 * 1024, 512 * 1024); + 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, 128 * 1024 * 1024, 512 * 1024)) { + 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, 128 * 1024 * 1024 + 16 * 1024 * 1024, + 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, 128 * 1024 * 1024 - 128 * 1024, + 128 * 1024); + 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, 128 * 1024 * 1024 - 128 * 1024, + 128 * 1024)) { + 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, 128 * 1024 * 1024 - 256 * 1024, + 1 * 1024 * 1024)) { + test_msg("Expected region not marked as free\n"); + return -ENOENT; + } + + if (cache->free_space_ctl->free_space != (1 * 1024 * 1024 + 4096)) { + test_msg("Cache free space is not 1Mb + 4Kb\n"); + return -EINVAL; + } + + offset = btrfs_find_space_for_alloc(cache, + 0, 1 * 1024 * 1024, 0, + &max_extent_size); + if (offset != (128 * 1024 * 1024 - 256 * 1024)) { + 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 != (128 * 1024 * 1024 + 16 * 1024 * 1024)) { + 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, 128 * 1024 * 1024 + 128 * 1024, + 128 * 1024, 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, + 128 * 1024 * 1024 - 512 * 1024, 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, + 128 * 1024 * 1024 - 768 * 1024); + 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, 128 * 1024 * 1024 + 128 * 1024, + 128 * 1024)) { + test_msg("Free space range missing\n"); + return -ENOENT; + } + if (!test_check_exists(cache, 128 * 1024 * 1024 - 768 * 1024, + 256 * 1024)) { + 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, + 128 * 1024 * 1024 - 768 * 1024)) { + 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, 128 * 1024 * 1024 - 512 * 1024, + 512 * 1024)) { + 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, 128 * 1024 * 1024 - 512 * 1024, + 512 * 1024); + 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, 128 * 1024 * 1024 - 512 * 1024, + 512 * 1024)) { + 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, 32 * 1024 * 1024, 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, 128 * 1024 * 1024, 128 * 1024); + 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, 128 * 1024 * 1024, 128 * 1024)) { + 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, 128 * 1024 * 1024 - 768 * 1024, + 1 * 1024 * 1024)) { + test_msg("Expected region not marked as free\n"); + return -ENOENT; + } + + if (cache->free_space_ctl->free_space != (1 * 1024 * 1024 + 8192)) { + test_msg("Cache free space is not 1Mb + 8Kb\n"); + return -EINVAL; + } + + offset = btrfs_find_space_for_alloc(cache, + 0, 1 * 1024 * 1024, 0, + &max_extent_size); + if (offset != (128 * 1024 * 1024 - 768 * 1024)) { + 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 != (32 * 1024 * 1024)) { + 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->use_bitmap = use_bitmap_op; + __btrfs_remove_free_space_cache(cache->free_space_ctl); + + return 0; +} + +int btrfs_test_free_space_cache(void) +{ + struct btrfs_block_group_cache *cache; + int ret; + + test_msg("Running btrfs free space cache tests\n"); + + cache = init_test_block_group(); + if (!cache) { + test_msg("Couldn't run the tests\n"); + return 0; + } + + 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_remove_free_space_cache(cache->free_space_ctl); + kfree(cache->free_space_ctl); + kfree(cache); + test_msg("Free space cache tests finished\n"); + return ret; +} -- cgit v1.2.3-54-g00ecf