From 4b52dff6d371b9b93bc99f64c32831ea9a8ec3ac Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 26 Jun 2007 10:06:50 -0400 Subject: [PATCH] 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 --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 5 ++--- fs/btrfs/extent-tree.c | 16 ++++++++-------- fs/btrfs/super.c | 2 +- fs/btrfs/transaction.c | 8 ++++++-- 5 files changed, 18 insertions(+), 14 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index fb6fffb71dd0..1998f86df08a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d7615e1578cc..7081729d5b16 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 8025e9f8ef19..7e550343aee7 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -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; } diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index c11ecf500202..2e797d5fb281 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -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); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index a5a63d471e43..3b2face593e9 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -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);