From 2a1eb4614d984d5cd4c928784e9afcf5c07f93be Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 13 Apr 2011 15:15:59 -0400 Subject: [PATCH] Btrfs: if we've already started a trans handle, use that one We currently track trans handles in current->journal_info, but we don't actually use it. This patch fixes it. This will cover the case where we have multiple people starting transactions down the call chain. This keeps us from having to allocate a new handle and all of that, we just increase the use count of the current handle, save the old block_rsv, and return. I tested this with xfstests and it worked out fine. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/transaction.c | 17 +++++++++++++++++ fs/btrfs/transaction.h | 2 ++ 2 files changed, 19 insertions(+) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 70bfb26df96..46f40564c16 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -184,6 +184,15 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root, if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) return ERR_PTR(-EROFS); + + if (current->journal_info) { + WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK); + h = current->journal_info; + h->use_count++; + h->orig_rsv = h->block_rsv; + h->block_rsv = NULL; + goto got_it; + } again: h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); if (!h) @@ -213,7 +222,9 @@ again: h->block_group = 0; h->bytes_reserved = 0; h->delayed_ref_updates = 0; + h->use_count = 1; h->block_rsv = NULL; + h->orig_rsv = NULL; smp_mb(); if (cur_trans->blocked && may_wait_transaction(root, type)) { @@ -241,6 +252,7 @@ again: } } +got_it: if (type != TRANS_JOIN_NOLOCK) mutex_lock(&root->fs_info->trans_mutex); record_root_in_trans(h, root); @@ -428,6 +440,11 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, struct btrfs_fs_info *info = root->fs_info; int count = 0; + if (--trans->use_count) { + trans->block_rsv = trans->orig_rsv; + return 0; + } + while (count < 4) { unsigned long cur = trans->delayed_ref_updates; trans->delayed_ref_updates = 0; diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 1f573f09dba..154314f80f8 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -47,11 +47,13 @@ struct btrfs_trans_handle { u64 transid; u64 block_group; u64 bytes_reserved; + unsigned long use_count; unsigned long blocks_reserved; unsigned long blocks_used; unsigned long delayed_ref_updates; struct btrfs_transaction *transaction; struct btrfs_block_rsv *block_rsv; + struct btrfs_block_rsv *orig_rsv; }; struct btrfs_pending_snapshot { -- 2.11.4.GIT