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/*
* Copyright (C) 2017 Oracle. 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"
static void free_extent_map_tree(struct extent_map_tree *em_tree)
{
struct extent_map *em;
struct rb_node *node;
while (!RB_EMPTY_ROOT(&em_tree->map)) {
node = rb_first(&em_tree->map);
em = rb_entry(node, struct extent_map, rb_node);
remove_extent_mapping(em_tree, em);
#ifdef CONFIG_BTRFS_DEBUG
if (refcount_read(&em->refs) != 1) {
test_msg(
"em leak: em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx) refs %d\n",
em->start, em->len, em->block_start,
em->block_len, refcount_read(&em->refs));
refcount_set(&em->refs, 1);
}
#endif
free_extent_map(em);
}
}
/*
* 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 void test_case_1(struct extent_map_tree *em_tree)
{
struct extent_map *em;
u64 start = 0;
u64 len = SZ_8K;
int ret;
em = alloc_extent_map();
if (!em)
/* Skip the test on error. */
return;
/* Add [0, 16K) */
em->start = 0;
em->len = SZ_16K;
em->block_start = 0;
em->block_len = SZ_16K;
ret = add_extent_mapping(em_tree, em, 0);
ASSERT(ret == 0);
free_extent_map(em);
/* Add [16K, 20K) following [0, 16K) */
em = alloc_extent_map();
if (!em)
goto out;
em->start = SZ_16K;
em->len = SZ_4K;
em->block_start = SZ_32K; /* avoid merging */
em->block_len = SZ_4K;
ret = add_extent_mapping(em_tree, em, 0);
ASSERT(ret == 0);
free_extent_map(em);
em = alloc_extent_map();
if (!em)
goto out;
/* Add [0, 8K), should return [0, 16K) instead. */
em->start = start;
em->len = len;
em->block_start = start;
em->block_len = len;
ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
if (ret)
test_msg("case1 [%llu %llu]: ret %d\n", start, start + len, ret);
if (em &&
(em->start != 0 || extent_map_end(em) != SZ_16K ||
em->block_start != 0 || em->block_len != SZ_16K))
test_msg(
"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
start, start + len, ret, em->start, em->len,
em->block_start, em->block_len);
free_extent_map(em);
out:
/* free memory */
free_extent_map_tree(em_tree);
}
/*
* Test scenario:
*
* Reading the inline ending up with EEXIST, ie. read an inline
* extent and discard page cache and read it again.
*/
static void test_case_2(struct extent_map_tree *em_tree)
{
struct extent_map *em;
int ret;
em = alloc_extent_map();
if (!em)
/* Skip the test on error. */
return;
/* Add [0, 1K) */
em->start = 0;
em->len = SZ_1K;
em->block_start = EXTENT_MAP_INLINE;
em->block_len = (u64)-1;
ret = add_extent_mapping(em_tree, em, 0);
ASSERT(ret == 0);
free_extent_map(em);
/* Add [4K, 4K) following [0, 1K) */
em = alloc_extent_map();
if (!em)
goto out;
em->start = SZ_4K;
em->len = SZ_4K;
em->block_start = SZ_4K;
em->block_len = SZ_4K;
ret = add_extent_mapping(em_tree, em, 0);
ASSERT(ret == 0);
free_extent_map(em);
em = alloc_extent_map();
if (!em)
goto out;
/* Add [0, 1K) */
em->start = 0;
em->len = SZ_1K;
em->block_start = EXTENT_MAP_INLINE;
em->block_len = (u64)-1;
ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
if (ret)
test_msg("case2 [0 1K]: ret %d\n", ret);
if (em &&
(em->start != 0 || extent_map_end(em) != SZ_1K ||
em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1))
test_msg(
"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
ret, em->start, em->len, em->block_start,
em->block_len);
free_extent_map(em);
out:
/* free memory */
free_extent_map_tree(em_tree);
}
int btrfs_test_extent_map()
{
struct extent_map_tree *em_tree;
test_msg("Running extent_map tests\n");
em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL);
if (!em_tree)
/* Skip the test on error. */
return 0;
extent_map_tree_init(em_tree);
test_case_1(em_tree);
test_case_2(em_tree);
kfree(em_tree);
return 0;
}
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