Btrfs: separate out tests into their own directory

The plan is to have a bunch of unit tests that run when btrfs is loaded when you
build with the appropriate config option.  My ultimate goal is to have a test
for every non-static function we have, but at first I'm going to focus on the
things that cause us the most problems.  To start out with this just adds a
tests/ directory and moves the existing free space cache tests into that
directory and sets up all of the infrastructure.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 395 insertions, 0 deletions

diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c
new file mode 100644
index 000000000000..6fc82010dc15
--- /dev/null
+++ b/fs/btrfs/tests/free-space-tests.c
@@ -0,0 +1,395 @@
+/*
+ * 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 "../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;
+
+        spin_lock_init(&cache->lock);
+        INIT_LIST_HEAD(&cache->list);
+        INIT_LIST_HEAD(&cache->cluster_list);
+        INIT_LIST_HEAD(&cache->new_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 peice %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 peices 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;
+}
+
+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;
+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;
+}