From 8d25a086eb104297e3ba1fdd180b04cfaaa84797 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Tue, 15 Jan 2013 06:27:25 +0000 Subject: [PATCH] Btrfs: Add ACCESS_ONCE() to transaction->abort accesses We may access and update transaction->aborted on the different CPUs without lock, so we need ACCESS_ONCE() wrapper to prevent the compiler from creating unsolicited accesses and make sure we can get the right value. Signed-off-by: Miao Xie Signed-off-by: Josef Bacik --- fs/btrfs/super.c | 2 +- fs/btrfs/transaction.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 99545df1b86..d8982e9601d 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -267,7 +267,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, function, line, errstr); return; } - trans->transaction->aborted = errno; + ACCESS_ONCE(trans->transaction->aborted) = errno; __btrfs_std_error(root->fs_info, function, line, errno, NULL); } /* diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 87fac9a21ea..0ef29611fad 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1468,7 +1468,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, goto cleanup_transaction; } - if (cur_trans->aborted) { + /* Stop the commit early if ->aborted is set */ + if (unlikely(ACCESS_ONCE(cur_trans->aborted))) { ret = cur_trans->aborted; goto cleanup_transaction; }