From 56e9f6ea32da884a2ec8ce7ed99171b8c5385d90 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 28 Nov 2019 16:03:00 +0100 Subject: [PATCH] btrfs: merge unlocking to common exit block in btrfs_commit_transaction The tree_log_mutex and reloc_mutex locks are properly nested so we can simplify error handling and add labels for them. This reduces line count of the function. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/transaction.c | 58 ++++++++++++++++++++------------------------------ 1 file changed, 23 insertions(+), 35 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index fdfdfc426539..702e0f2b8307 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2194,10 +2194,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * core function of the snapshot creation. */ ret = create_pending_snapshots(trans); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; /* * We insert the dir indexes of the snapshots and update the inode @@ -2210,16 +2208,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * the nodes and leaves. */ ret = btrfs_run_delayed_items(trans); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; /* * make sure none of the code above managed to slip in a @@ -2245,11 +2239,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) mutex_lock(&fs_info->tree_log_mutex); ret = commit_fs_roots(trans); - if (ret) { - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_tree_log; /* * Since the transaction is done, we can apply the pending changes @@ -2267,29 +2258,20 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * new delayed refs. Must handle them or qgroup can be wrong. */ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); - if (ret) { - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_tree_log; /* * Since fs roots are all committed, we can get a quite accurate * new_roots. So let's do quota accounting. */ ret = btrfs_qgroup_account_extents(trans); - if (ret < 0) { - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret < 0) + goto unlock_tree_log; ret = commit_cowonly_roots(trans); - if (ret) { - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_tree_log; /* * The tasks which save the space cache and inode cache may also @@ -2297,9 +2279,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) */ if (TRANS_ABORTED(cur_trans)) { ret = cur_trans->aborted; - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; + goto unlock_tree_log; } btrfs_prepare_extent_commit(fs_info); @@ -2346,6 +2326,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (ret) { btrfs_handle_fs_error(fs_info, ret, "Error while writing out transaction"); + /* + * reloc_mutex has been unlocked, tree_log_mutex is still held + * but we can't jump to unlock_tree_log causing double unlock + */ mutex_unlock(&fs_info->tree_log_mutex); goto scrub_continue; } @@ -2394,6 +2378,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) return ret; +unlock_tree_log: + mutex_unlock(&fs_info->tree_log_mutex); +unlock_reloc: + mutex_unlock(&fs_info->reloc_mutex); scrub_continue: btrfs_scrub_continue(fs_info); cleanup_transaction: -- 2.11.0