linux/fs/btrfs/super.c
Chris Mason 4b52dff6d3 Btrfs: Fix super block updates during transaction commit
The super block written during commit was not consistent with the state of
the trees.  This change adds an in-memory copy of the super so that we can
make sure to write out consistent data during a commit.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-26 10:06:50 -04:00

200 lines
4.9 KiB
C

/*
* Copyright (C) 2007 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/module.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#define BTRFS_SUPER_MAGIC 0x9123682E
static struct super_operations btrfs_super_ops;
static void btrfs_put_super (struct super_block * sb)
{
struct btrfs_root *root = btrfs_sb(sb);
int ret;
ret = close_ctree(root);
if (ret) {
printk("close ctree returns %d\n", ret);
}
sb->s_fs_info = NULL;
}
static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
{
struct inode * inode;
struct dentry * root_dentry;
struct btrfs_super_block *disk_super;
struct btrfs_root *tree_root;
struct btrfs_inode *bi;
int err;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_magic = BTRFS_SUPER_MAGIC;
sb->s_op = &btrfs_super_ops;
sb->s_time_gran = 1;
tree_root = open_ctree(sb);
if (!tree_root || IS_ERR(tree_root)) {
printk("btrfs: open_ctree failed\n");
return -EIO;
}
sb->s_fs_info = tree_root;
disk_super = tree_root->fs_info->disk_super;
inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
tree_root);
bi = BTRFS_I(inode);
bi->location.objectid = inode->i_ino;
bi->location.offset = 0;
bi->location.flags = 0;
bi->root = tree_root;
btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
if (!inode) {
err = -ENOMEM;
goto fail_close;
}
if (inode->i_state & I_NEW) {
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
root_dentry = d_alloc_root(inode);
if (!root_dentry) {
iput(inode);
err = -ENOMEM;
goto fail_close;
}
sb->s_root = root_dentry;
btrfs_transaction_queue_work(tree_root, HZ * 30);
return 0;
fail_close:
close_ctree(tree_root);
return err;
}
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
root = btrfs_sb(sb);
sb->s_dirt = 0;
if (!wait) {
filemap_flush(root->fs_info->btree_inode->i_mapping);
return 0;
}
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sb->s_dirt = 0;
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static void btrfs_write_super(struct super_block *sb)
{
sb->s_dirt = 0;
}
static int btrfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data,
btrfs_fill_super, mnt);
}
static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct btrfs_root *root = btrfs_sb(dentry->d_sb);
struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
buf->f_namelen = BTRFS_NAME_LEN;
buf->f_blocks = btrfs_super_total_blocks(disk_super);
buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
buf->f_bavail = buf->f_bfree;
buf->f_bsize = dentry->d_sb->s_blocksize;
buf->f_type = BTRFS_SUPER_MAGIC;
return 0;
}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
.get_sb = btrfs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static struct super_operations btrfs_super_ops = {
.delete_inode = btrfs_delete_inode,
.put_super = btrfs_put_super,
.read_inode = btrfs_read_locked_inode,
.write_super = btrfs_write_super,
.sync_fs = btrfs_sync_fs,
.write_inode = btrfs_write_inode,
.dirty_inode = btrfs_dirty_inode,
.alloc_inode = btrfs_alloc_inode,
.destroy_inode = btrfs_destroy_inode,
.statfs = btrfs_statfs,
};
static int __init init_btrfs_fs(void)
{
int err;
btrfs_init_transaction_sys();
err = btrfs_init_cachep();
if (err)
return err;
return register_filesystem(&btrfs_fs_type);
}
static void __exit exit_btrfs_fs(void)
{
btrfs_exit_transaction_sys();
btrfs_destroy_cachep();
unregister_filesystem(&btrfs_fs_type);
}
module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");