linux/fs/btrfs/tests/btrfs-tests.c
Sasha Levin f1e3c28949 btrfs: prevent RCU warning when dereferencing radix tree slot
Mark the dereference as protected by lock. Not doing so triggers
an RCU warning since the radix tree assumed that RCU is in use.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:22 -07:00

172 lines
4.4 KiB
C

/*
* 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/fs.h>
#include <linux/mount.h>
#include <linux/magic.h>
#include "btrfs-tests.h"
#include "../ctree.h"
#include "../volumes.h"
#include "../disk-io.h"
#include "../qgroup.h"
static struct vfsmount *test_mnt = NULL;
static const struct super_operations btrfs_test_super_ops = {
.alloc_inode = btrfs_alloc_inode,
.destroy_inode = btrfs_test_destroy_inode,
};
static struct dentry *btrfs_test_mount(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
return mount_pseudo(fs_type, "btrfs_test:", &btrfs_test_super_ops,
NULL, BTRFS_TEST_MAGIC);
}
static struct file_system_type test_type = {
.name = "btrfs_test_fs",
.mount = btrfs_test_mount,
.kill_sb = kill_anon_super,
};
struct inode *btrfs_new_test_inode(void)
{
return new_inode(test_mnt->mnt_sb);
}
int btrfs_init_test_fs(void)
{
int ret;
ret = register_filesystem(&test_type);
if (ret) {
printk(KERN_ERR "btrfs: cannot register test file system\n");
return ret;
}
test_mnt = kern_mount(&test_type);
if (IS_ERR(test_mnt)) {
printk(KERN_ERR "btrfs: cannot mount test file system\n");
unregister_filesystem(&test_type);
return ret;
}
return 0;
}
void btrfs_destroy_test_fs(void)
{
kern_unmount(test_mnt);
unregister_filesystem(&test_type);
}
struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(void)
{
struct btrfs_fs_info *fs_info = kzalloc(sizeof(struct btrfs_fs_info),
GFP_NOFS);
if (!fs_info)
return fs_info;
fs_info->fs_devices = kzalloc(sizeof(struct btrfs_fs_devices),
GFP_NOFS);
if (!fs_info->fs_devices) {
kfree(fs_info);
return NULL;
}
fs_info->super_copy = kzalloc(sizeof(struct btrfs_super_block),
GFP_NOFS);
if (!fs_info->super_copy) {
kfree(fs_info->fs_devices);
kfree(fs_info);
return NULL;
}
if (init_srcu_struct(&fs_info->subvol_srcu)) {
kfree(fs_info->fs_devices);
kfree(fs_info->super_copy);
kfree(fs_info);
return NULL;
}
spin_lock_init(&fs_info->buffer_lock);
spin_lock_init(&fs_info->qgroup_lock);
spin_lock_init(&fs_info->qgroup_op_lock);
spin_lock_init(&fs_info->super_lock);
spin_lock_init(&fs_info->fs_roots_radix_lock);
spin_lock_init(&fs_info->tree_mod_seq_lock);
mutex_init(&fs_info->qgroup_ioctl_lock);
mutex_init(&fs_info->qgroup_rescan_lock);
rwlock_init(&fs_info->tree_mod_log_lock);
fs_info->running_transaction = NULL;
fs_info->qgroup_tree = RB_ROOT;
fs_info->qgroup_ulist = NULL;
atomic64_set(&fs_info->tree_mod_seq, 0);
INIT_LIST_HEAD(&fs_info->dirty_qgroups);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
return fs_info;
}
static void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
{
struct radix_tree_iter iter;
void **slot;
spin_lock(&fs_info->buffer_lock);
restart:
radix_tree_for_each_slot(slot, &fs_info->buffer_radix, &iter, 0) {
struct extent_buffer *eb;
eb = radix_tree_deref_slot_protected(slot, &fs_info->buffer_lock);
if (!eb)
continue;
/* Shouldn't happen but that kind of thinking creates CVE's */
if (radix_tree_exception(eb)) {
if (radix_tree_deref_retry(eb))
goto restart;
continue;
}
spin_unlock(&fs_info->buffer_lock);
free_extent_buffer_stale(eb);
spin_lock(&fs_info->buffer_lock);
}
spin_unlock(&fs_info->buffer_lock);
btrfs_free_qgroup_config(fs_info);
btrfs_free_fs_roots(fs_info);
cleanup_srcu_struct(&fs_info->subvol_srcu);
kfree(fs_info->super_copy);
kfree(fs_info->fs_devices);
kfree(fs_info);
}
void btrfs_free_dummy_root(struct btrfs_root *root)
{
if (!root)
return;
if (root->node)
free_extent_buffer(root->node);
if (root->fs_info)
btrfs_free_dummy_fs_info(root->fs_info);
kfree(root);
}