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authorArne Jansen <sensille@gmx.net>2011-09-14 12:37:00 +0200
committerJan Schmidt <list.btrfs@jan-o-sch.net>2012-01-04 16:12:42 +0100
commit00f04b88791ff49dc64ada18819d40a5b0671709 (patch)
treefd85a5f4b374aac035388b0cbf8ef572578d5578 /fs/btrfs/transaction.c
parent5b25f70f4200766355cdabda604e131d2fb6010d (diff)
downloadop-kernel-dev-00f04b88791ff49dc64ada18819d40a5b0671709.zip
op-kernel-dev-00f04b88791ff49dc64ada18819d40a5b0671709.tar.gz
Btrfs: add sequence numbers to delayed refs
Sequence numbers are needed to reconstruct the backrefs of a given extent to a certain point in time. The total set of backrefs consist of the set of backrefs recorded on disk plus the enqueued delayed refs for it that existed at that moment. This patch also adds a list that records all delayed refs which are currently in the process of being added. When walking all refs of an extent in btrfs_find_all_roots(), we freeze the current state of delayed refs, honor anythinh up to this point and prevent processing newer delayed refs to assert consistency. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Diffstat (limited to 'fs/btrfs/transaction.c')
-rw-r--r--fs/btrfs/transaction.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index a2bfedc..31a7393 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -36,6 +36,8 @@ static noinline void put_transaction(struct btrfs_transaction *transaction)
WARN_ON(atomic_read(&transaction->use_count) == 0);
if (atomic_dec_and_test(&transaction->use_count)) {
BUG_ON(!list_empty(&transaction->list));
+ WARN_ON(transaction->delayed_refs.root.rb_node);
+ WARN_ON(!list_empty(&transaction->delayed_refs.seq_head));
memset(transaction, 0, sizeof(*transaction));
kmem_cache_free(btrfs_transaction_cachep, transaction);
}
@@ -108,8 +110,10 @@ loop:
cur_trans->delayed_refs.num_heads = 0;
cur_trans->delayed_refs.flushing = 0;
cur_trans->delayed_refs.run_delayed_start = 0;
+ cur_trans->delayed_refs.seq = 1;
spin_lock_init(&cur_trans->commit_lock);
spin_lock_init(&cur_trans->delayed_refs.lock);
+ INIT_LIST_HEAD(&cur_trans->delayed_refs.seq_head);
INIT_LIST_HEAD(&cur_trans->pending_snapshots);
list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
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