Commit 4b52dff6 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse

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: default avatarChris Mason <chris.mason@oracle.com>
parent 79c44584
......@@ -306,6 +306,7 @@ struct btrfs_fs_info {
u64 generation;
struct btrfs_transaction *running_transaction;
struct btrfs_super_block *disk_super;
struct btrfs_super_block super_copy;
struct buffer_head *sb_buffer;
struct super_block *sb;
struct inode *btree_inode;
......
......@@ -471,6 +471,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
if (!fs_info->sb_buffer)
goto fail_iput;
disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
fs_info->disk_super = disk_super;
memcpy(&fs_info->super_copy, disk_super, sizeof(fs_info->super_copy));
if (!btrfs_super_root(disk_super))
goto fail_sb_buffer;
......@@ -479,7 +481,6 @@ struct btrfs_root *open_ctree(struct super_block *sb)
btrfs_super_total_blocks(disk_super) <<
fs_info->btree_inode->i_blkbits);
fs_info->disk_super = disk_super;
if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->magic))) {
......@@ -527,8 +528,6 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
int ret;
struct buffer_head *bh = root->fs_info->sb_buffer;
btrfs_set_super_root(root->fs_info->disk_super,
bh_blocknr(root->fs_info->tree_root->node));
lock_buffer(bh);
WARN_ON(atomic_read(&bh->b_count) < 1);
clear_buffer_dirty(bh);
......
......@@ -796,8 +796,8 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) {
ins.objectid = extent_root->fs_info->extent_tree_insert[i];
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super,
super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(&info->super_copy,
super_blocks_used + 1);
ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
sizeof(extent_item));
......@@ -892,8 +892,8 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
BUG_ON(ret);
}
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super,
super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(&info->super_copy,
super_blocks_used - num_blocks);
ret = btrfs_del_item(trans, extent_root, path);
if (ret) {
......@@ -1032,7 +1032,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
info->extent_tree_prealloc_nr = 0;
}
if (search_end == (u64)-1)
search_end = btrfs_super_total_blocks(info->disk_super);
search_end = btrfs_super_total_blocks(&info->super_copy);
if (hint_block) {
block_group = btrfs_lookup_block_group(info, hint_block);
block_group = btrfs_find_block_group(root, block_group,
......@@ -1361,8 +1361,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
}
}
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(&info->super_copy, super_blocks_used +
num_blocks);
ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
sizeof(extent_item));
......@@ -1737,7 +1737,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
BTRFS_BLOCK_GROUP_AVAIL);
}
if (key.objectid >=
btrfs_super_total_blocks(info->disk_super))
btrfs_super_total_blocks(&info->super_copy))
break;
}
......
......@@ -144,7 +144,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
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->disk_super;
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);
......
......@@ -380,6 +380,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
else
prev_trans->use_count++;
}
btrfs_set_super_generation(&root->fs_info->super_copy,
cur_trans->transid);
btrfs_set_super_root(&root->fs_info->super_copy,
bh_blocknr(root->fs_info->tree_root->node));
memcpy(root->fs_info->disk_super, &root->fs_info->super_copy,
sizeof(root->fs_info->super_copy));
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_write_and_wait_transaction(trans, root);
......@@ -389,8 +395,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
put_transaction(prev_trans);
mutex_unlock(&root->fs_info->trans_mutex);
}
btrfs_set_super_generation(root->fs_info->disk_super,
cur_trans->transid);
BUG_ON(ret);
write_ctree_super(trans, root);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment