/*
 * 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 "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 - 10][10 - 4096][  4096 - 8192 ][8192 - 12288]
 * [hole ][inline][ hole ][ regular ][regular1 split][    hole    ]
 *
 * [ 12288 - 20480][20480 - 24576][  24576 - 28672  ][28672 - 36864][36864 - 45056]
 * [regular1 split][   prealloc1 ][prealloc1 written][   prealloc1 ][ compressed  ]
 *
 * [45056 - 49152][49152-53248][53248-61440][61440-65536][     65536+81920   ]
 * [ compressed1 ][  regular  ][compressed1][  regular  ][ hole but no extent]
 *
 * [81920-86016]
 * [  regular  ]
 */
static void setup_file_extents(struct btrfs_root *root)
{
        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 = 4096;

        /* 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, 4095, 4095, 0, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        disk_bytenr += 4096;
        offset += 4095;

        /*
         * Now for 3 extents that were split from a hole punch so we test
         * offsets properly.
         */
        insert_extent(root, offset, 4096, 16384, 0, disk_bytenr, 16384,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 4096, 4096, 0, 0, 0, BTRFS_FILE_EXTENT_REG,
                      0, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 8192, 16384, 8192, disk_bytenr, 16384,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 8192;
        disk_bytenr += 16384;

        /* Now for a unwritten prealloc extent */
        insert_extent(root, offset, 4096, 4096, 0, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += 4096;

        /*
         * We want to jack up disk_bytenr a little more so the em stuff doesn't
         * merge our records.
         */
        disk_bytenr += 8192;

        /*
         * 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, 4096, 16384, 0, disk_bytenr, 16384,
                      BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 4096, 16384, 4096, disk_bytenr, 16384,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 8192, 16384, 8192, disk_bytenr, 16384,
                      BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
        slot++;
        offset += 8192;
        disk_bytenr += 16384;

        /* Now a normal compressed extent */
        insert_extent(root, offset, 8192, 8192, 0, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_REG, BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += 8192;
        /* No merges */
        disk_bytenr += 8192;

        /* Now a split compressed extent */
        insert_extent(root, offset, 4096, 16384, 0, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_REG, BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 4096, 4096, 0, disk_bytenr + 4096, 4096,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 4096;
        insert_extent(root, offset, 8192, 16384, 8192, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_REG, BTRFS_COMPRESS_ZLIB, slot);
        slot++;
        offset += 8192;
        disk_bytenr += 8192;

        /* Now extents that have a hole but no hole extent */
        insert_extent(root, offset, 4096, 4096, 0, disk_bytenr, 4096,
                      BTRFS_FILE_EXTENT_REG, 0, slot);
        slot++;
        offset += 16384;
        disk_bytenr += 4096;
        insert_extent(root, offset, 4096, 4096, 0, disk_bytenr, 4096,
                      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(void)
{
        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;

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

        /*
         * We do this since btrfs_get_extent wants to assign em->bdev to
         * root->fs_info->fs_devices->latest_bdev.
         */
        root->fs_info = btrfs_alloc_dummy_fs_info();
        if (!root->fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

        root->node = alloc_dummy_extent_buffer(NULL, 4096);
        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 accidently 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(inode, NULL, 0, 0, 4096, 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;
        }
        if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
                test_msg("Vacancy flag wasn't set properly\n");
                goto out;
        }
        free_extent_map(em);
        btrfs_drop_extent_cache(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);

        em = btrfs_get_extent(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(inode, NULL, 0, offset, 4096, 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 != 4091) {
                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(inode, NULL, 0, offset, 4096, 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(inode, NULL, 0, offset, 4096, 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 != 4095) {
                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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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;
        }
        disk_bytenr = em->block_start;
        orig_start = em->start;
        offset = em->start + em->len;
        free_extent_map(em);

        em = btrfs_get_extent(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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);

        em = btrfs_get_extent(inode, NULL, 0, offset, 4096, 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 != 8192) {
                test_msg("Unexpected extent wanted start %llu len 8192, 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 != 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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 != 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(inode, NULL, 0, offset, 4096, 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 != 8192) {
                test_msg("Unexpected extent wanted start %llu len 8192, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 8192) {
                test_msg("Unexpected extent wanted start %llu len 8192, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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);

        em = btrfs_get_extent(inode, NULL, 0, offset, 4096, 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 != 8192) {
                test_msg("Unexpected extent wanted start %llu len 8192, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset + 6, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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);

        em = btrfs_get_extent(inode, NULL, 0, offset, 4096 * 1024, 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 != 12288) {
                test_msg("Unexpected extent wanted start %llu len 12288, got "
                         "start %llu len %llu\n", offset, 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(inode, NULL, 0, offset, 4096, 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 != 4096) {
                test_msg("Unexpected extent wanted start %llu len 4096, 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;
        }
        ret = 0;
out:
        if (!IS_ERR(em))
                free_extent_map(em);
        iput(inode);
        btrfs_free_dummy_root(root);
        return ret;
}

static int test_hole_first(void)
{
        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;

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

        root->fs_info = btrfs_alloc_dummy_fs_info();
        if (!root->fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

        root->node = alloc_dummy_extent_buffer(NULL, 4096);
        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, 4096, 4096, 4096, 0, 4096, 4096,
                      BTRFS_FILE_EXTENT_REG, 0, 1);
        em = btrfs_get_extent(inode, NULL, 0, 0, 8192, 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 != 4096) {
                test_msg("Unexpected extent wanted start 0 len 4096, got start "
                         "%llu len %llu\n", 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(inode, NULL, 0, 4096, 8192, 0);
        if (IS_ERR(em)) {
                test_msg("Got an error when we shouldn't have\n");
                goto out;
        }
        if (em->block_start != 4096) {
                test_msg("Expected a real extent, got %llu\n", em->block_start);
                goto out;
        }
        if (em->start != 4096 || em->len != 4096) {
                test_msg("Unexpected extent wanted start 4096 len 4096, got "
                         "start %llu len %llu\n", 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);
        return ret;
}

static int test_extent_accounting(void)
{
        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;
        }

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

        root->fs_info = btrfs_alloc_dummy_fs_info();
        if (!root->fs_info) {
                test_msg("Couldn't allocate dummy fs info\n");
                goto out;
        }

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

        /* [BTRFS_MAX_EXTENT_SIZE] */
        BTRFS_I(inode)->outstanding_extents++;
        ret = btrfs_set_extent_delalloc(inode, 0, BTRFS_MAX_EXTENT_SIZE - 1,
                                        NULL);
        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][4k] */
        BTRFS_I(inode)->outstanding_extents++;
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE,
                                        BTRFS_MAX_EXTENT_SIZE + 4095, NULL);
        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][4K HOLE][the rest] */
        ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
                               BTRFS_MAX_EXTENT_SIZE >> 1,
                               (BTRFS_MAX_EXTENT_SIZE >> 1) + 4095,
                               EXTENT_DELALLOC | EXTENT_DIRTY |
                               EXTENT_UPTODATE | EXTENT_DO_ACCOUNTING, 0, 0,
                               NULL, GFP_KERNEL);
        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][4K] */
        BTRFS_I(inode)->outstanding_extents++;
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE >> 1,
                                        (BTRFS_MAX_EXTENT_SIZE >> 1) + 4095,
                                        NULL);
        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+4K][4K HOLE][BTRFS_MAX_EXTENT_SIZE+4K]
         *
         * I'm artificially adding 2 to outstanding_extents because in the
         * buffered IO case we'd add things up as we go, but I don't feel like
         * doing that here, this isn't the interesting case we want to test.
         */
        BTRFS_I(inode)->outstanding_extents += 2;
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE + 8192,
                                        (BTRFS_MAX_EXTENT_SIZE << 1) + 12287,
                                        NULL);
        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+4k][4k][BTRFS_MAX_EXTENT_SIZE+4k] */
        BTRFS_I(inode)->outstanding_extents++;
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE+4096,
                                        BTRFS_MAX_EXTENT_SIZE+8191, NULL);
        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+4096,
                               BTRFS_MAX_EXTENT_SIZE+8191,
                               EXTENT_DIRTY | EXTENT_DELALLOC |
                               EXTENT_DO_ACCOUNTING | EXTENT_UPTODATE, 0, 0,
                               NULL, GFP_KERNEL);
        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.
         */
        BTRFS_I(inode)->outstanding_extents++;
        ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE+4096,
                                        BTRFS_MAX_EXTENT_SIZE+8191, NULL);
        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_DO_ACCOUNTING | EXTENT_UPTODATE, 0, 0,
                               NULL, GFP_KERNEL);
        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_DO_ACCOUNTING | EXTENT_UPTODATE, 0, 0,
                                 NULL, GFP_KERNEL);
        iput(inode);
        btrfs_free_dummy_root(root);
        return ret;
}

int btrfs_test_inodes(void)
{
        int ret;

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

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