/*
 * 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/types.h>
#include "btrfs-tests.h"
#include "../ctree.h"
#include "../btrfs_inode.h"
#include "../disk-io.h"
#include "../extent_io.h"
#include "../volumes.h"
#include "../compression.h"

static void insert_extent(struct btrfs_root *root, u64 start, u64 len,
                          u64 ram_bytes, u64 offset, u64 disk_bytenr,
                          u64 disk_len, u32 type, u8 compression, int slot)
{
        struct btrfs_path path;
        struct btrfs_file_extent_item *fi;
        struct extent_buffer *leaf = root->node;
        struct btrfs_key key;
        u32 value_len = sizeof(struct btrfs_file_extent_item);

        if (type == BTRFS_FILE_EXTENT_INLINE)
                value_len += len;
        memset(&path, 0, sizeof(path));

        path.nodes[0] = leaf;
        path.slots[0] = slot;

        key.objectid = BTRFS_FIRST_FREE_OBJECTID;
        key.type = BTRFS_EXTENT_DATA_KEY;
        key.offset = start;

        setup_items_for_insert(root, &path, &key, &value_len, value_len,
                               value_len + sizeof(struct btrfs_item), 1);
        fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
        btrfs_set_file_extent_generation(leaf, fi, 1);
        btrfs_set_file_extent_type(leaf, fi, type);
        btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
        btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_len);
        btrfs_set_file_extent_offset(leaf, fi, offset);
        btrfs_set_file_extent_num_bytes(leaf, fi, len);
        btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
        btrfs_set_file_extent_compression(leaf, fi, compression);
        btrfs_set_file_extent_encryption(leaf, fi, 0);
        btrfs_set_file_extent_other_encoding(leaf, fi, 0);
}

static void insert_inode_item_key(struct btrfs_root *root)
{
        struct btrfs_path path;
        struct extent_buffer *leaf = root->node;
        struct btrfs_key key;
        u32 value_len = 0;

        memset(&path, 0, sizeof(path));

        path.nodes[0] = leaf;
        path.slots[0] = 0;

        key.objectid = BTRFS_INODE_ITEM_KEY;
        key.type = BTRFS_INODE_ITEM_KEY;
        key.offset = 0;

        setup_items_for_insert(root, &path, &key, &value_len, value_len,
                               value_len + sizeof(struct btrfs_item), 1);
}

/*
 * Build the most complicated map of extents the earth has ever seen.  We want
 * this so we can test all of the corner cases of btrfs_get_extent.  Here is a
 * diagram of how the extents will look though this may not be possible we still
 * want to make sure everything acts normally (the last number is not inclusive)
 *
 * [0 - 5][5 -  6][     6 - 4096     ][ 4096 - 4100][4100 - 8195][8195 - 12291]
 * [hole ][inline][hole but no extent][  hole   ][   regular ][regular1 split]
 *
 * [12291 - 16387][16387 - 24579][24579 - 28675][ 28675 - 32771][32771 - 36867 ]
 * [    hole    ][regular1 split][   prealloc ][   prealloc1  ][prealloc1 written]
 *
 * [36867 - 45059][45059 - 53251][53251 - 57347][57347 - 61443][61443- 69635]
 * [  prealloc1  ][ compressed  ][ compressed1 ][    regular  ][ compressed1]
 *
 * [69635-73731][   73731 - 86019   ][86019-90115]
 * [  regular  ][ hole but no extent][  regular  ]
 */
static void setup_file_extents(struct btrfs_root *root, u32 sectorsize)
{
        int slot = 0;
        u64 disk_bytenr = SZ_1M;
        u64 offset = 0;

        /* First we want a hole */
        insert_extent(root, offset, 5, 5, 0, 0, 0, BTRFS_FILE_EXTENT_REG, 0,
                      slot);
        slot++;
        offset += 5;

        /*
         * Now we want an inline extent, I don't think this is possible but hey
         * why not?  Also keep in mind if we have an inline extent it counts as
         * the whole first page.  If we were to expand it we would have to cow
         * and we wouldn't have an inline extent anymore.
         */
        insert_extent(root, offset, 1, 1, 0, 0, 0, BTRFS_FILE_EXTENT_INLINE, 0,
                      slot);
        slot++;
        offset = sectorsize;

        /* Now another hole */
        insert_extent(root, offset, 4, 4, 0, 0, 0, BTRFS_FILE_EXTENT_REG, 0,
                      slot);
        slot++;
        offset += 4;

        /* Now for a regular extent */
        insert_extent(root, offset, sectorsize - 1, sectorsize - 1, 0,
                      disk_bytenr, sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        disk_bytenr += sectorsize;
        offset += sectorsize - 1;

        /*
         * Now for 3 extents that were split from a hole punch so we test
         * offsets properly.
         */
        insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
                      4 * sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, sectorsize, sectorsize, 0, 0, 0,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
                      2 * sectorsize, disk_bytenr, 4 * sectorsize,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 2 * sectorsize;
        disk_bytenr += 4 * sectorsize;

        /* Now for a unwritten prealloc extent */
        insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
                sectorsize, BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += sectorsize;

        /*
         * We want to jack up disk_bytenr a little more so the em stuff doesn't
         * merge our records.
         */
        disk_bytenr += 2 * sectorsize;

        /*
         * Now for a partially written prealloc extent, basically the same as
         * the hole punch example above.  Ram_bytes never changes when you mark
         * extents written btw.
         */
        insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
                      4 * sectorsize, BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, sectorsize, 4 * sectorsize, sectorsize,
                      disk_bytenr, 4 * sectorsize, BTRFS_FILE_EXTENT_REG, 0,
                      slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
                      2 * sectorsize, disk_bytenr, 4 * sectorsize,
                      BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += 2 * sectorsize;
        disk_bytenr += 4 * sectorsize;

        /* Now a normal compressed extent */
        insert_extent(root, offset, 2 * sectorsize, 2 * sectorsize, 0,
                      disk_bytenr, sectorsize, BTRFS_FILE_EXTENT_REG,
                      BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += 2 * sectorsize;
        /* No merges */
        disk_bytenr += 2 * sectorsize;

        /* Now a split compressed extent */
        insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
                      sectorsize, BTRFS_FILE_EXTENT_REG,
                      BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, sectorsize, sectorsize, 0,
                      disk_bytenr + sectorsize, sectorsize,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += sectorsize;
        insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
                      2 * sectorsize, disk_bytenr, sectorsize,
                      BTRFS_FILE_EXTENT_REG, BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += 2 * sectorsize;
        disk_bytenr += 2 * sectorsize;

        /* Now extents that have a hole but no hole extent */
        insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
                      sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 4 * sectorsize;
        disk_bytenr += sectorsize;
        insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
                      sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
}

static unsigned long prealloc_only = 0;
static unsigned long compressed_only = 0;
static unsigned long vacancy_only = 0;

static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize)
{
        struct btrfs_fs_info *fs_info = NULL;
        struct inode *inode = NULL;
        struct btrfs_root *root = NULL;
        struct extent_map *em = NULL;
        u64 orig_start;
        u64 disk_bytenr;
        u64 offset;
        int ret = -ENOMEM;

        inode = btrfs_new_test_inode();
        if (!inode) {
                test_msg("Couldn't allocate inode\n");
                return ret;
        }

        BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
        BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
        BTRFS_I(inode)->location.offset = 0;

        fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
        if (!fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

        root = btrfs_alloc_dummy_root(fs_info);
        if (IS_ERR(root)) {
                test_msg("Couldn't allocate root\n");
                goto out;
        }

        root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
        if (!root->node) {
                test_msg("Couldn't allocate dummy buffer\n");
                goto out;
        }

        /*
         * We will just free a dummy node if it's ref count is 2 so we need an
         * extra ref so our searches don't accidentally release our page.
         */
        extent_buffer_get(root->node);
        btrfs_set_header_nritems(root->node, 0);
        btrfs_set_header_level(root->node, 0);
        ret = -EINVAL;

        /* First with no extents */
        BTRFS_I(inode)->root = root;
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, 0, sectorsize, 0);
        if (IS_ERR(em)) {
                em = NULL;
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole, got %llu\n", em->block_start);
                goto out;
        }
        free_extent_map(em);
        btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);

        /*
         * All of the magic numbers are based on the mapping setup in
         * setup_file_extents, so if you change anything there you need to
         * update the comment and update the expected values below.
         */
        setup_file_extents(root, sectorsize);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, 0, (u64)-1, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != 0 || em->len != 5) {
                test_msg("Unexpected extent wanted start 0 len 5, got start "
                         "%llu len %llu\n", em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_INLINE) {
                test_msg("Expected an inline, got %llu\n", em->block_start);
                goto out;
        }

        if (em->start != offset || em->len != (sectorsize - 5)) {
                test_msg("Unexpected extent wanted start %llu len 1, got start "
                         "%llu len %llu\n", offset, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        /*
         * We don't test anything else for inline since it doesn't get set
         * unless we have a page for it to write into.  Maybe we should change
         * this?
         */
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != 4) {
                test_msg("Unexpected extent wanted start %llu len 4, got start "
                         "%llu len %llu\n", offset, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* Regular extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize - 1) {
                test_msg("Unexpected extent wanted start %llu len 4095, got "
                         "start %llu len %llu\n", offset, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* The next 3 are split extents */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        disk_bytenr = em->block_start;
        orig_start = em->start;
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != 2 * sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, 2 * sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != orig_start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n",
                         orig_start, em->orig_start);
                goto out;
        }
        disk_bytenr += (em->start - orig_start);
        if (em->block_start != disk_bytenr) {
                test_msg("Wrong block start, want %llu, have %llu\n",
                         disk_bytenr, em->block_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* Prealloc extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != prealloc_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         prealloc_only, em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* The next 3 are a half written prealloc extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != prealloc_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         prealloc_only, em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        disk_bytenr = em->block_start;
        orig_start = em->start;
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_HOLE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != orig_start) {
                test_msg("Unexpected orig offset, wanted %llu, have %llu\n",
                         orig_start, em->orig_start);
                goto out;
        }
        if (em->block_start != (disk_bytenr + (em->start - em->orig_start))) {
                test_msg("Unexpected block start, wanted %llu, have %llu\n",
                         disk_bytenr + (em->start - em->orig_start),
                         em->block_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != 2 * sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, 2 * sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != prealloc_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         prealloc_only, em->flags);
                goto out;
        }
        if (em->orig_start != orig_start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", orig_start,
                         em->orig_start);
                goto out;
        }
        if (em->block_start != (disk_bytenr + (em->start - em->orig_start))) {
                test_msg("Unexpected block start, wanted %llu, have %llu\n",
                         disk_bytenr + (em->start - em->orig_start),
                         em->block_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* Now for the compressed extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != 2 * sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u,"
                        "got start %llu len %llu\n",
                        offset, 2 * sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != compressed_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         compressed_only, em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n",
                         em->start, em->orig_start);
                goto out;
        }
        if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
                test_msg("Unexpected compress type, wanted %d, got %d\n",
                         BTRFS_COMPRESS_ZLIB, em->compress_type);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* Split compressed extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u,"
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != compressed_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         compressed_only, em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n",
                         em->start, em->orig_start);
                goto out;
        }
        if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
                test_msg("Unexpected compress type, wanted %d, got %d\n",
                         BTRFS_COMPRESS_ZLIB, em->compress_type);
                goto out;
        }
        disk_bytenr = em->block_start;
        orig_start = em->start;
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != disk_bytenr) {
                test_msg("Block start does not match, want %llu got %llu\n",
                         disk_bytenr, em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != 2 * sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, 2 * sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != compressed_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         compressed_only, em->flags);
                goto out;
        }
        if (em->orig_start != orig_start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n",
                         em->start, orig_start);
                goto out;
        }
        if (em->compress_type != BTRFS_COMPRESS_ZLIB) {
                test_msg("Unexpected compress type, wanted %d, got %d\n",
                         BTRFS_COMPRESS_ZLIB, em->compress_type);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        /* A hole between regular extents but no hole extent */
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset + 6,
                        sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, SZ_4M, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole extent, got %llu\n", em->block_start);
                goto out;
        }
        /*
         * Currently we just return a length that we requested rather than the
         * length of the actual hole, if this changes we'll have to change this
         * test.
         */
        if (em->start != offset || em->len != 3 * sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u, "
                        "got start %llu len %llu\n",
                        offset, 3 * sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != vacancy_only) {
                test_msg("Unexpected flags set, want %lu have %lu\n",
                         vacancy_only, em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != offset || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %llu len %u,"
                        "got start %llu len %llu\n",
                        offset, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, want 0 have %lu\n", em->flags);
                goto out;
        }
        if (em->orig_start != em->start) {
                test_msg("Wrong orig offset, want %llu, have %llu\n", em->start,
                         em->orig_start);
                goto out;
        }
        ret = 0;
out:
        if (!IS_ERR(em))
                free_extent_map(em);
        iput(inode);
        btrfs_free_dummy_root(root);
        btrfs_free_dummy_fs_info(fs_info);
        return ret;
}

static int test_hole_first(u32 sectorsize, u32 nodesize)
{
        struct btrfs_fs_info *fs_info = NULL;
        struct inode *inode = NULL;
        struct btrfs_root *root = NULL;
        struct extent_map *em = NULL;
        int ret = -ENOMEM;

        inode = btrfs_new_test_inode();
        if (!inode) {
                test_msg("Couldn't allocate inode\n");
                return ret;
        }

        BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
        BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
        BTRFS_I(inode)->location.offset = 0;

        fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
        if (!fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

        root = btrfs_alloc_dummy_root(fs_info);
        if (IS_ERR(root)) {
                test_msg("Couldn't allocate root\n");
                goto out;
        }

        root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
        if (!root->node) {
                test_msg("Couldn't allocate dummy buffer\n");
                goto out;
        }

        extent_buffer_get(root->node);
        btrfs_set_header_nritems(root->node, 0);
        btrfs_set_header_level(root->node, 0);
        BTRFS_I(inode)->root = root;
        ret = -EINVAL;

        /*
         * Need a blank inode item here just so we don't confuse
         * btrfs_get_extent.
         */
        insert_inode_item_key(root);
        insert_extent(root, sectorsize, sectorsize, sectorsize, 0, sectorsize,
                      sectorsize, BTRFS_FILE_EXTENT_REG, 0, 1);
        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, 0, 2 * sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != EXTENT_MAP_HOLE) {
                test_msg("Expected a hole, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != 0 || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start 0 len %u, "
                        "got start %llu len %llu\n",
                        sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != vacancy_only) {
                test_msg("Wrong flags, wanted %lu, have %lu\n", vacancy_only,
                         em->flags);
                goto out;
        }
        free_extent_map(em);

        em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, sectorsize,
                        2 * sectorsize, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != sectorsize) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != sectorsize || em->len != sectorsize) {
                test_msg("Unexpected extent wanted start %u len %u, "
                        "got start %llu len %llu\n",
                        sectorsize, sectorsize, em->start, em->len);
                goto out;
        }
        if (em->flags != 0) {
                test_msg("Unexpected flags set, wanted 0 got %lu\n",
                         em->flags);
                goto out;
        }
        ret = 0;
out:
        if (!IS_ERR(em))
                free_extent_map(em);
        iput(inode);
        btrfs_free_dummy_root(root);
        btrfs_free_dummy_fs_info(fs_info);
        return ret;
}

static int test_extent_accounting(u32 sectorsize, u32 nodesize)
{
        struct btrfs_fs_info *fs_info = NULL;
        struct inode *inode = NULL;
        struct btrfs_root *root = NULL;
        int ret = -ENOMEM;

        inode = btrfs_new_test_inode();
        if (!inode) {
                test_msg("Couldn't allocate inode\n");
                return ret;
        }

        fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
        if (!fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

        root = btrfs_alloc_dummy_root(fs_info);
        if (IS_ERR(root)) {
                test_msg("Couldn't allocate root\n");
                goto out;
        }

        BTRFS_I(inode)->root = root;
        btrfs_test_inode_set_ops(inode);

        /* [BTRFS_MAX_EXTENT_SIZE] */
        ret = btrfs_set_extent_delalloc(inode, 0, BTRFS_MAX_EXTENT_SIZE - 1, 0,
                                        NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 1) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 1, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /* [BTRFS_MAX_EXTENT_SIZE][sectorsize] */
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE,
                                        BTRFS_MAX_EXTENT_SIZE + sectorsize - 1,
                                        0, NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 2) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 2, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /* [BTRFS_MAX_EXTENT_SIZE/2][sectorsize HOLE][the rest] */
        ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
                               BTRFS_MAX_EXTENT_SIZE >> 1,
                               (BTRFS_MAX_EXTENT_SIZE >> 1) + sectorsize - 1,
                               EXTENT_DELALLOC | EXTENT_DIRTY |
                               EXTENT_UPTODATE, 0, 0, NULL);

        if (ret) {
                test_msg("clear_extent_bit returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 2) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 2, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /* [BTRFS_MAX_EXTENT_SIZE][sectorsize] */
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE >> 1,
                                        (BTRFS_MAX_EXTENT_SIZE >> 1)
                                        + sectorsize - 1,
                                        0, NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 2) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 2, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /*
         * [BTRFS_MAX_EXTENT_SIZE+sectorsize][sectorsize HOLE][BTRFS_MAX_EXTENT_SIZE+sectorsize]
         */
        ret = btrfs_set_extent_delalloc(inode,
                        BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize,
                        (BTRFS_MAX_EXTENT_SIZE << 1) + 3 * sectorsize - 1,
                        0, NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 4) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 4, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /*
        * [BTRFS_MAX_EXTENT_SIZE+sectorsize][sectorsize][BTRFS_MAX_EXTENT_SIZE+sectorsize]
        */
        ret = btrfs_set_extent_delalloc(inode,
                        BTRFS_MAX_EXTENT_SIZE + sectorsize,
                        BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 3) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 3, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /* [BTRFS_MAX_EXTENT_SIZE+4k][4K HOLE][BTRFS_MAX_EXTENT_SIZE+4k] */
        ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
                               BTRFS_MAX_EXTENT_SIZE + sectorsize,
                               BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1,
                               EXTENT_DIRTY | EXTENT_DELALLOC |
                               EXTENT_UPTODATE, 0, 0, NULL);
        if (ret) {
                test_msg("clear_extent_bit returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 4) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 4, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /*
         * Refill the hole again just for good measure, because I thought it
         * might fail and I'd rather satisfy my paranoia at this point.
         */
        ret = btrfs_set_extent_delalloc(inode,
                        BTRFS_MAX_EXTENT_SIZE + sectorsize,
                        BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL, 0);
        if (ret) {
                test_msg("btrfs_set_extent_delalloc returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents != 3) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 3, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }

        /* Empty */
        ret = clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
                               EXTENT_DIRTY | EXTENT_DELALLOC |
                               EXTENT_UPTODATE, 0, 0, NULL);
        if (ret) {
                test_msg("clear_extent_bit returned %d\n", ret);
                goto out;
        }
        if (BTRFS_I(inode)->outstanding_extents) {
                ret = -EINVAL;
                test_msg("Miscount, wanted 0, got %u\n",
                         BTRFS_I(inode)->outstanding_extents);
                goto out;
        }
        ret = 0;
out:
        if (ret)
                clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
                                 EXTENT_DIRTY | EXTENT_DELALLOC |
                                 EXTENT_UPTODATE, 0, 0, NULL);
        iput(inode);
        btrfs_free_dummy_root(root);
        btrfs_free_dummy_fs_info(fs_info);
        return ret;
}

int btrfs_test_inodes(u32 sectorsize, u32 nodesize)
{
        int ret;

        set_bit(EXTENT_FLAG_COMPRESSED, &compressed_only);
        set_bit(EXTENT_FLAG_PREALLOC, &prealloc_only);

        test_msg("Running btrfs_get_extent tests\n");
        ret = test_btrfs_get_extent(sectorsize, nodesize);
        if (ret)
                return ret;
        test_msg("Running hole first btrfs_get_extent test\n");
        ret = test_hole_first(sectorsize, nodesize);
        if (ret)
                return ret;
        test_msg("Running outstanding_extents tests\n");
        return test_extent_accounting(sectorsize, nodesize);
}