// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 Oracle.  All rights reserved.
 */

#include <linux/types.h>
#include "btrfs-tests.h"
#include "../ctree.h"
#include "../btrfs_inode.h"
#include "../volumes.h"
#include "../disk-io.h"
#include "../block-group.h"

static int free_extent_map_tree(struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        struct rb_node *node;
        int ret = 0;

        write_lock(&em_tree->lock);
        while (!RB_EMPTY_ROOT(&em_tree->root)) {
                node = rb_first(&em_tree->root);
                em = rb_entry(node, struct extent_map, rb_node);
                btrfs_remove_extent_mapping(inode, em);

#ifdef CONFIG_BTRFS_DEBUG
                if (refcount_read(&em->refs) != 1) {
                        ret = -EINVAL;
                        test_err(
"em leak: em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu offset %llu) refs %d",
                                 em->start, em->len, em->disk_bytenr,
                                 em->disk_num_bytes, em->offset,
                                 refcount_read(&em->refs));

                        refcount_set(&em->refs, 1);
                }
#endif
                btrfs_free_extent_map(em);
        }
        write_unlock(&em_tree->lock);

        return ret;
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet, there is a file
 * extent [0, 16K), followed by another file extent [16K, 20K), two dio reads
 * are entering btrfs_get_extent() concurrently, t1 is reading [8K, 16K), t2 is
 * reading [0, 8K)
 *
 *     t1                            t2
 *  btrfs_get_extent()              btrfs_get_extent()
 *    -> lookup_extent_mapping()      ->lookup_extent_mapping()
 *    -> add_extent_mapping(0, 16K)
 *    -> return em
 *                                    ->add_extent_mapping(0, 16K)
 *                                    -> #handle -EEXIST
 */
static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        u64 start = 0;
        u64 len = SZ_8K;
        int ret;
        int ret2;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /* Add [0, 16K) */
        em->start = 0;
        em->len = SZ_16K;
        em->disk_bytenr = 0;
        em->disk_num_bytes = SZ_16K;
        em->ram_bytes = SZ_16K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [0, 16K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        /* Add [16K, 20K) following [0, 16K)  */
        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        em->start = SZ_16K;
        em->len = SZ_4K;
        em->disk_bytenr = SZ_32K; /* avoid merging */
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_4K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [16K, 20K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /* Add [0, 8K), should return [0, 16K) instead. */
        em->start = start;
        em->len = len;
        em->disk_bytenr = start;
        em->disk_num_bytes = len;
        em->ram_bytes = len;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret) {
                test_err("case1 [%llu %llu]: ret %d", start, start + len, ret);
                goto out;
        }
        if (!em) {
                test_err("case1 [%llu %llu]: no extent map returned",
                         start, start + len);
                ret = -ENOENT;
                goto out;
        }
        if (em->start != 0 || btrfs_extent_map_end(em) != SZ_16K ||
            em->disk_bytenr != 0 || em->disk_num_bytes != SZ_16K) {
                test_err(
"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu",
                         start, start + len, ret, em->start, em->len,
                         em->disk_bytenr, em->disk_num_bytes);
                ret = -EINVAL;
        }
        btrfs_free_extent_map(em);
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Test scenario:
 *
 * Reading the inline ending up with EEXIST, ie. read an inline
 * extent and discard page cache and read it again.
 */
static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        int ret;
        int ret2;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /*
         * Add [0, 1K) which is inlined. And the extent map length must
         * be one block.
         */
        em->start = 0;
        em->len = SZ_4K;
        em->disk_bytenr = EXTENT_MAP_INLINE;
        em->disk_num_bytes = 0;
        em->ram_bytes = SZ_1K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [0, 1K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        /* Add [4K, 8K) following [0, 1K)  */
        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        em->start = SZ_4K;
        em->len = SZ_4K;
        em->disk_bytenr = SZ_4K;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_4K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [4K, 8K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /* Add [0, 1K) */
        em->start = 0;
        em->len = SZ_4K;
        em->disk_bytenr = EXTENT_MAP_INLINE;
        em->disk_num_bytes = 0;
        em->ram_bytes = SZ_1K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret) {
                test_err("case2 [0 1K]: ret %d", ret);
                goto out;
        }
        if (!em) {
                test_err("case2 [0 1K]: no extent map returned");
                ret = -ENOENT;
                goto out;
        }
        if (em->start != 0 || btrfs_extent_map_end(em) != SZ_4K ||
            em->disk_bytenr != EXTENT_MAP_INLINE) {
                test_err(
"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu",
                         ret, em->start, em->len, em->disk_bytenr);
                ret = -EINVAL;
        }
        btrfs_free_extent_map(em);
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

static int __test_case_3(struct btrfs_fs_info *fs_info,
                         struct btrfs_inode *inode, u64 start)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        u64 len = SZ_4K;
        int ret;
        int ret2;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /* Add [4K, 8K) */
        em->start = SZ_4K;
        em->len = SZ_4K;
        em->disk_bytenr = SZ_4K;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_4K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [4K, 8K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /* Add [0, 16K) */
        em->start = 0;
        em->len = SZ_16K;
        em->disk_bytenr = 0;
        em->disk_num_bytes = SZ_16K;
        em->ram_bytes = SZ_16K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, start, len);
        write_unlock(&em_tree->lock);
        if (ret) {
                test_err("case3 [%llu %llu): ret %d",
                         start, start + len, ret);
                goto out;
        }
        if (!em) {
                test_err("case3 [%llu %llu): no extent map returned",
                         start, start + len);
                ret = -ENOENT;
                goto out;
        }
        /*
         * Since bytes within em are contiguous, em->block_start is identical to
         * em->start.
         */
        if (start < em->start || start + len > btrfs_extent_map_end(em) ||
            em->start != btrfs_extent_map_block_start(em)) {
                test_err(
"case3 [%llu %llu): ret %d em (start %llu len %llu disk_bytenr %llu block_len %llu)",
                         start, start + len, ret, em->start, em->len,
                         em->disk_bytenr, em->disk_num_bytes);
                ret = -EINVAL;
        }
        btrfs_free_extent_map(em);
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet.
 * There is a file extent [0, 16K), two jobs are running concurrently
 * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
 * read from [0, 4K) or [8K, 12K) or [12K, 16K).
 *
 * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
 *
 *         t1                       t2
 *  cow_file_range()         btrfs_get_extent()
 *                            -> lookup_extent_mapping()
 *   -> add_extent_mapping()
 *                            -> add_extent_mapping()
 */
static int test_case_3(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        int ret;

        ret = __test_case_3(fs_info, inode, 0);
        if (ret)
                return ret;
        ret = __test_case_3(fs_info, inode, SZ_8K);
        if (ret)
                return ret;
        ret = __test_case_3(fs_info, inode, (12 * SZ_1K));

        return ret;
}

static int __test_case_4(struct btrfs_fs_info *fs_info,
                         struct btrfs_inode *inode, u64 start)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        u64 len = SZ_4K;
        int ret;
        int ret2;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /* Add [0K, 8K) */
        em->start = 0;
        em->len = SZ_8K;
        em->disk_bytenr = 0;
        em->disk_num_bytes = SZ_8K;
        em->ram_bytes = SZ_8K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [0, 8K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /* Add [8K, 32K) */
        em->start = SZ_8K;
        em->len = 24 * SZ_1K;
        em->disk_bytenr = SZ_16K; /* avoid merging */
        em->disk_num_bytes = 24 * SZ_1K;
        em->ram_bytes = 24 * SZ_1K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("cannot add extent range [8K, 32K)");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }
        /* Add [0K, 32K) */
        em->start = 0;
        em->len = SZ_32K;
        em->disk_bytenr = 0;
        em->disk_num_bytes = SZ_32K;
        em->ram_bytes = SZ_32K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, start, len);
        write_unlock(&em_tree->lock);
        if (ret) {
                test_err("case4 [%llu %llu): ret %d",
                         start, start + len, ret);
                goto out;
        }
        if (!em) {
                test_err("case4 [%llu %llu): no extent map returned",
                         start, start + len);
                ret = -ENOENT;
                goto out;
        }
        if (start < em->start || start + len > btrfs_extent_map_end(em)) {
                test_err(
"case4 [%llu %llu): ret %d, added wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu)",
                         start, start + len, ret, em->start, em->len,
                         em->disk_bytenr, em->disk_num_bytes);
                ret = -EINVAL;
        }
        btrfs_free_extent_map(em);
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet.
 * There is a file extent [0, 32K), two jobs are running concurrently
 * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
 * read from [0, 4K) or [4K, 8K).
 *
 * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).
 *
 *         t1                                t2
 *  btrfs_get_blocks_direct()          btrfs_get_blocks_direct()
 *   -> btrfs_get_extent()              -> btrfs_get_extent()
 *       -> lookup_extent_mapping()
 *       -> add_extent_mapping()            -> lookup_extent_mapping()
 *          # load [0, 32K)
 *   -> btrfs_new_extent_direct()
 *       -> btrfs_drop_extent_cache()
 *          # split [0, 32K)
 *       -> add_extent_mapping()
 *          # add [8K, 32K)
 *                                          -> add_extent_mapping()
 *                                             # handle -EEXIST when adding
 *                                             # [0, 32K)
 */
static int test_case_4(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        int ret;

        ret = __test_case_4(fs_info, inode, 0);
        if (ret)
                return ret;
        ret = __test_case_4(fs_info, inode, SZ_4K);

        return ret;
}

static int add_compressed_extent(struct btrfs_inode *inode,
                                 u64 start, u64 len, u64 block_start)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        int ret;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        em->start = start;
        em->len = len;
        em->disk_bytenr = block_start;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = len;
        em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        btrfs_free_extent_map(em);
        if (ret < 0) {
                test_err("cannot add extent map [%llu, %llu)", start, start + len);
                return ret;
        }

        return 0;
}

struct extent_range {
        u64 start;
        u64 len;
};

/* The valid states of the tree after every drop, as described below. */
struct extent_range valid_ranges[][7] = {
        {
          { .start = 0,                 .len = SZ_8K },         /* [0, 8K) */
          { .start = SZ_4K * 3,         .len = SZ_4K * 3},      /* [12k, 24k) */
          { .start = SZ_4K * 6,         .len = SZ_4K * 3},      /* [24k, 36k) */
          { .start = SZ_32K + SZ_4K,    .len = SZ_4K},          /* [36k, 40k) */
          { .start = SZ_4K * 10,        .len = SZ_4K * 6},      /* [40k, 64k) */
        },
        {
          { .start = 0,                 .len = SZ_8K },         /* [0, 8K) */
          { .start = SZ_4K * 5,         .len = SZ_4K},          /* [20k, 24k) */
          { .start = SZ_4K * 6,         .len = SZ_4K * 3},      /* [24k, 36k) */
          { .start = SZ_32K + SZ_4K,    .len = SZ_4K},          /* [36k, 40k) */
          { .start = SZ_4K * 10,        .len = SZ_4K * 6},      /* [40k, 64k) */
        },
        {
          { .start = 0,                 .len = SZ_8K },         /* [0, 8K) */
          { .start = SZ_4K * 5,         .len = SZ_4K},          /* [20k, 24k) */
          { .start = SZ_4K * 6,         .len = SZ_4K},          /* [24k, 28k) */
          { .start = SZ_32K,            .len = SZ_4K},          /* [32k, 36k) */
          { .start = SZ_32K + SZ_4K,    .len = SZ_4K},          /* [36k, 40k) */
          { .start = SZ_4K * 10,        .len = SZ_4K * 6},      /* [40k, 64k) */
        },
        {
          { .start = 0,                 .len = SZ_8K},          /* [0, 8K) */
          { .start = SZ_4K * 5,         .len = SZ_4K},          /* [20k, 24k) */
          { .start = SZ_4K * 6,         .len = SZ_4K},          /* [24k, 28k) */
        }
};

static int validate_range(struct extent_map_tree *em_tree, int index)
{
        struct rb_node *n;
        int i;

        for (i = 0, n = rb_first(&em_tree->root);
             valid_ranges[index][i].len && n;
             i++, n = rb_next(n)) {
                struct extent_map *entry = rb_entry(n, struct extent_map, rb_node);

                if (entry->start != valid_ranges[index][i].start) {
                        test_err("mapping has start %llu expected %llu",
                                 entry->start, valid_ranges[index][i].start);
                        return -EINVAL;
                }

                if (entry->len != valid_ranges[index][i].len) {
                        test_err("mapping has len %llu expected %llu",
                                 entry->len, valid_ranges[index][i].len);
                        return -EINVAL;
                }
        }

        /*
         * We exited because we don't have any more entries in the extent_map
         * but we still expect more valid entries.
         */
        if (valid_ranges[index][i].len) {
                test_err("missing an entry");
                return -EINVAL;
        }

        /* We exited the loop but still have entries in the extent map. */
        if (n) {
                test_err("we have a left over entry in the extent map we didn't expect");
                return -EINVAL;
        }

        return 0;
}

/*
 * Test scenario:
 *
 * Test the various edge cases of btrfs_drop_extent_map_range, create the
 * following ranges
 *
 * [0, 12k)[12k, 24k)[24k, 36k)[36k, 40k)[40k,64k)
 *
 * And then we'll drop:
 *
 * [8k, 12k) - test the single front split
 * [12k, 20k) - test the single back split
 * [28k, 32k) - test the double split
 * [32k, 64k) - test whole em dropping
 *
 * They'll have the EXTENT_FLAG_COMPRESSED flag set to keep the em tree from
 * merging the em's.
 */
static int test_case_5(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        u64 start, end;
        int ret;
        int ret2;

        test_msg("Running btrfs_drop_extent_map_range tests");

        /* [0, 12k) */
        ret = add_compressed_extent(inode, 0, SZ_4K * 3, 0);
        if (ret) {
                test_err("cannot add extent range [0, 12K)");
                goto out;
        }

        /* [12k, 24k) */
        ret = add_compressed_extent(inode, SZ_4K * 3, SZ_4K * 3, SZ_4K);
        if (ret) {
                test_err("cannot add extent range [12k, 24k)");
                goto out;
        }

        /* [24k, 36k) */
        ret = add_compressed_extent(inode, SZ_4K * 6, SZ_4K * 3, SZ_8K);
        if (ret) {
                test_err("cannot add extent range [12k, 24k)");
                goto out;
        }

        /* [36k, 40k) */
        ret = add_compressed_extent(inode, SZ_32K + SZ_4K, SZ_4K, SZ_4K * 3);
        if (ret) {
                test_err("cannot add extent range [12k, 24k)");
                goto out;
        }

        /* [40k, 64k) */
        ret = add_compressed_extent(inode, SZ_4K * 10, SZ_4K * 6, SZ_16K);
        if (ret) {
                test_err("cannot add extent range [12k, 24k)");
                goto out;
        }

        /* Drop [8k, 12k) */
        start = SZ_8K;
        end = (3 * SZ_4K) - 1;
        btrfs_drop_extent_map_range(inode, start, end, false);
        ret = validate_range(&inode->extent_tree, 0);
        if (ret)
                goto out;

        /* Drop [12k, 20k) */
        start = SZ_4K * 3;
        end = SZ_16K + SZ_4K - 1;
        btrfs_drop_extent_map_range(inode, start, end, false);
        ret = validate_range(&inode->extent_tree, 1);
        if (ret)
                goto out;

        /* Drop [28k, 32k) */
        start = SZ_32K - SZ_4K;
        end = SZ_32K - 1;
        btrfs_drop_extent_map_range(inode, start, end, false);
        ret = validate_range(&inode->extent_tree, 2);
        if (ret)
                goto out;

        /* Drop [32k, 64k) */
        start = SZ_32K;
        end = SZ_64K - 1;
        btrfs_drop_extent_map_range(inode, start, end, false);
        ret = validate_range(&inode->extent_tree, 3);
        if (ret)
                goto out;
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Test the btrfs_add_extent_mapping helper which will attempt to create an em
 * for areas between two existing ems.  Validate it doesn't do this when there
 * are two unmerged em's side by side.
 */
static int test_case_6(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em = NULL;
        int ret;
        int ret2;

        ret = add_compressed_extent(inode, 0, SZ_4K, 0);
        if (ret)
                goto out;

        ret = add_compressed_extent(inode, SZ_4K, SZ_4K, 0);
        if (ret)
                goto out;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        em->start = SZ_4K;
        em->len = SZ_4K;
        em->disk_bytenr = SZ_16K;
        em->disk_num_bytes = SZ_16K;
        em->ram_bytes = SZ_16K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, 0, SZ_8K);
        write_unlock(&em_tree->lock);

        if (ret != 0) {
                test_err("got an error when adding our em: %d", ret);
                goto out;
        }

        ret = -EINVAL;
        if (em->start != 0) {
                test_err("unexpected em->start at %llu, wanted 0", em->start);
                goto out;
        }
        if (em->len != SZ_4K) {
                test_err("unexpected em->len %llu, expected 4K", em->len);
                goto out;
        }
        ret = 0;
out:
        btrfs_free_extent_map(em);
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Regression test for btrfs_drop_extent_map_range.  Calling with skip_pinned ==
 * true would mess up the start/end calculations and subsequent splits would be
 * incorrect.
 */
static int test_case_7(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        int ret;
        int ret2;

        test_msg("Running btrfs_drop_extent_cache with pinned");

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /* [0, 16K), pinned */
        em->start = 0;
        em->len = SZ_16K;
        em->disk_bytenr = 0;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_16K;
        em->flags |= (EXTENT_FLAG_PINNED | EXTENT_FLAG_COMPRESS_ZLIB);
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("couldn't add extent map");
                goto out;
        }
        btrfs_free_extent_map(em);

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /* [32K, 48K), not pinned */
        em->start = SZ_32K;
        em->len = SZ_16K;
        em->disk_bytenr = SZ_32K;
        em->disk_num_bytes = SZ_16K;
        em->ram_bytes = SZ_16K;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        if (ret < 0) {
                test_err("couldn't add extent map");
                goto out;
        }
        btrfs_free_extent_map(em);

        /*
         * Drop [0, 36K) This should skip the [0, 4K) extent and then split the
         * [32K, 48K) extent.
         */
        btrfs_drop_extent_map_range(inode, 0, (36 * SZ_1K) - 1, true);

        /* Make sure our extent maps look sane. */
        ret = -EINVAL;

        em = btrfs_lookup_extent_mapping(em_tree, 0, SZ_16K);
        if (!em) {
                test_err("didn't find an em at 0 as expected");
                goto out;
        }

        if (em->start != 0) {
                test_err("em->start is %llu, expected 0", em->start);
                goto out;
        }

        if (em->len != SZ_16K) {
                test_err("em->len is %llu, expected 16K", em->len);
                goto out;
        }

        btrfs_free_extent_map(em);

        read_lock(&em_tree->lock);
        em = btrfs_lookup_extent_mapping(em_tree, SZ_16K, SZ_16K);
        read_unlock(&em_tree->lock);
        if (em) {
                test_err("found an em when we weren't expecting one");
                goto out;
        }

        read_lock(&em_tree->lock);
        em = btrfs_lookup_extent_mapping(em_tree, SZ_32K, SZ_16K);
        read_unlock(&em_tree->lock);
        if (!em) {
                test_err("didn't find an em at 32K as expected");
                goto out;
        }

        if (em->start != (36 * SZ_1K)) {
                test_err("em->start is %llu, expected 36K", em->start);
                goto out;
        }

        if (em->len != (12 * SZ_1K)) {
                test_err("em->len is %llu, expected 12K", em->len);
                goto out;
        }

        if (btrfs_extent_map_block_start(em) != SZ_32K + SZ_4K) {
                test_err("em->block_start is %llu, expected 36K",
                         btrfs_extent_map_block_start(em));
                goto out;
        }

        btrfs_free_extent_map(em);

        read_lock(&em_tree->lock);
        em = btrfs_lookup_extent_mapping(em_tree, 48 * SZ_1K, (u64)-1);
        read_unlock(&em_tree->lock);
        if (em) {
                test_err("found an unexpected em above 48K");
                goto out;
        }

        ret = 0;
out:
        btrfs_free_extent_map(em);
        /* Unpin our extent to prevent warning when removing it below. */
        ret2 = btrfs_unpin_extent_cache(inode, 0, SZ_16K, 0);
        if (ret == 0)
                ret = ret2;
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

/*
 * Test a regression for compressed extent map adjustment when we attempt to
 * add an extent map that is partially overlapped by another existing extent
 * map. The resulting extent map offset was left unchanged despite having
 * incremented its start offset.
 */
static int test_case_8(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
{
        struct extent_map_tree *em_tree = &inode->extent_tree;
        struct extent_map *em;
        int ret;
        int ret2;

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                return -ENOMEM;
        }

        /* Compressed extent for the file range [120K, 128K). */
        em->start = SZ_1K * 120;
        em->len = SZ_8K;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_8K;
        em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
        write_unlock(&em_tree->lock);
        btrfs_free_extent_map(em);
        if (ret < 0) {
                test_err("couldn't add extent map for range [120K, 128K)");
                goto out;
        }

        em = btrfs_alloc_extent_map();
        if (!em) {
                test_std_err(TEST_ALLOC_EXTENT_MAP);
                ret = -ENOMEM;
                goto out;
        }

        /*
         * Compressed extent for the file range [108K, 144K), which overlaps
         * with the [120K, 128K) we previously inserted.
         */
        em->start = SZ_1K * 108;
        em->len = SZ_1K * 36;
        em->disk_num_bytes = SZ_4K;
        em->ram_bytes = SZ_1K * 36;
        em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;

        /*
         * Try to add the extent map but with a search range of [140K, 144K),
         * this should succeed and adjust the extent map to the range
         * [128K, 144K), with a length of 16K and an offset of 20K.
         *
         * This simulates a scenario where in the subvolume tree of an inode we
         * have a compressed file extent item for the range [108K, 144K) and we
         * have an overlapping compressed extent map for the range [120K, 128K),
         * which was created by an encoded write, but its ordered extent was not
         * yet completed, so the subvolume tree doesn't have yet the file extent
         * item for that range - we only have the extent map in the inode's
         * extent map tree.
         */
        write_lock(&em_tree->lock);
        ret = btrfs_add_extent_mapping(inode, &em, SZ_1K * 140, SZ_4K);
        write_unlock(&em_tree->lock);
        btrfs_free_extent_map(em);
        if (ret < 0) {
                test_err("couldn't add extent map for range [108K, 144K)");
                goto out;
        }

        if (em->start != SZ_128K) {
                test_err("unexpected extent map start %llu (should be 128K)", em->start);
                ret = -EINVAL;
                goto out;
        }
        if (em->len != SZ_16K) {
                test_err("unexpected extent map length %llu (should be 16K)", em->len);
                ret = -EINVAL;
                goto out;
        }
        if (em->offset != SZ_1K * 20) {
                test_err("unexpected extent map offset %llu (should be 20K)", em->offset);
                ret = -EINVAL;
                goto out;
        }
out:
        ret2 = free_extent_map_tree(inode);
        if (ret == 0)
                ret = ret2;

        return ret;
}

struct rmap_test_vector {
        u64 raid_type;
        u64 physical_start;
        u64 data_stripe_size;
        u64 num_data_stripes;
        u64 num_stripes;
        /* Assume we won't have more than 5 physical stripes */
        u64 data_stripe_phys_start[5];
        bool expected_mapped_addr;
        /* Physical to logical addresses */
        u64 mapped_logical[5];
};

static int test_rmap_block(struct btrfs_fs_info *fs_info,
                           struct rmap_test_vector *test)
{
        struct btrfs_chunk_map *map;
        u64 AUTO_KFREE(logical);
        int i, out_ndaddrs, out_stripe_len;
        int ret;

        map = btrfs_alloc_chunk_map(test->num_stripes, GFP_KERNEL);
        if (!map) {
                test_std_err(TEST_ALLOC_CHUNK_MAP);
                return -ENOMEM;
        }

        /* Start at 4GiB logical address */
        map->start = SZ_4G;
        map->chunk_len = test->data_stripe_size * test->num_data_stripes;
        map->stripe_size = test->data_stripe_size;
        map->num_stripes = test->num_stripes;
        map->type = test->raid_type;

        for (i = 0; i < map->num_stripes; i++) {
                struct btrfs_device *dev = btrfs_alloc_dummy_device(fs_info);

                if (IS_ERR(dev)) {
                        test_err("cannot allocate device");
                        ret = PTR_ERR(dev);
                        goto out;
                }
                map->stripes[i].dev = dev;
                map->stripes[i].physical = test->data_stripe_phys_start[i];
        }

        ret = btrfs_add_chunk_map(fs_info, map);
        if (ret) {
                test_err("error adding chunk map to mapping tree");
                btrfs_free_chunk_map(map);
                return ret;
        }

        ret = btrfs_rmap_block(fs_info, map->start, btrfs_sb_offset(1),
                               &logical, &out_ndaddrs, &out_stripe_len);
        if (ret || (out_ndaddrs == 0 && test->expected_mapped_addr)) {
                test_err("didn't rmap anything but expected %d",
                         test->expected_mapped_addr);
                goto out;
        }

        if (out_stripe_len != BTRFS_STRIPE_LEN) {
                test_err("calculated stripe length doesn't match");
                ret = -EINVAL;
                goto out;
        }

        if (out_ndaddrs != test->expected_mapped_addr) {
                for (i = 0; i < out_ndaddrs; i++)
                        test_msg("mapped %llu", logical[i]);
                test_err("unexpected number of mapped addresses: %d", out_ndaddrs);
                ret = -EINVAL;
                goto out;
        }

        for (i = 0; i < out_ndaddrs; i++) {
                if (logical[i] != test->mapped_logical[i]) {
                        test_err("unexpected logical address mapped");
                        ret = -EINVAL;
                        goto out;
                }
        }

        ret = 0;
out:
        btrfs_remove_chunk_map(fs_info, map);
        return ret;
}

int btrfs_test_extent_map(void)
{
        struct btrfs_fs_info *fs_info = NULL;
        struct inode *inode;
        struct btrfs_root *root = NULL;
        int ret = 0, i;
        struct rmap_test_vector rmap_tests[] = {
                {
                        /*
                         * Test a chunk with 2 data stripes one of which
                         * intersects the physical address of the super block
                         * is correctly recognized.
                         */
                        .raid_type = BTRFS_BLOCK_GROUP_RAID1,
                        .physical_start = SZ_64M - SZ_4M,
                        .data_stripe_size = SZ_256M,
                        .num_data_stripes = 2,
                        .num_stripes = 2,
                        .data_stripe_phys_start =
                                {SZ_64M - SZ_4M, SZ_64M - SZ_4M + SZ_256M},
                        .expected_mapped_addr = true,
                        .mapped_logical= {SZ_4G + SZ_4M}
                },
                {
                        /*
                         * Test that out-of-range physical addresses are
                         * ignored
                         */

                         /* SINGLE chunk type */
                        .raid_type = 0,
                        .physical_start = SZ_4G,
                        .data_stripe_size = SZ_256M,
                        .num_data_stripes = 1,
                        .num_stripes = 1,
                        .data_stripe_phys_start = {SZ_256M},
                        .expected_mapped_addr = false,
                        .mapped_logical = {0}
                }
        };

        test_msg("running extent_map tests");

        /*
         * Note: the fs_info is not set up completely, we only need
         * fs_info::fsid for the tracepoint.
         *
         * And all the immediate numbers are based on 4K blocksize,
         * thus we have to use 4K as sectorsize no matter the page size.
         */
        fs_info = btrfs_alloc_dummy_fs_info(SZ_4K, SZ_4K);
        if (!fs_info) {
                test_std_err(TEST_ALLOC_FS_INFO);
                return -ENOMEM;
        }

        inode = btrfs_new_test_inode();
        if (!inode) {
                test_std_err(TEST_ALLOC_INODE);
                ret = -ENOMEM;
                goto out;
        }

        root = btrfs_alloc_dummy_root(fs_info);
        if (IS_ERR(root)) {
                test_std_err(TEST_ALLOC_ROOT);
                ret = PTR_ERR(root);
                root = NULL;
                goto out;
        }

        BTRFS_I(inode)->root = root;

        ret = test_case_1(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_2(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_3(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_4(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_5(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_6(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_7(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;
        ret = test_case_8(fs_info, BTRFS_I(inode));
        if (ret)
                goto out;

        test_msg("running rmap tests");
        for (i = 0; i < ARRAY_SIZE(rmap_tests); i++) {
                ret = test_rmap_block(fs_info, &rmap_tests[i]);
                if (ret)
                        goto out;
        }

out:
        iput(inode);
        btrfs_free_dummy_root(root);
        btrfs_free_dummy_fs_info(fs_info);

        return ret;
}