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 <miaox@xxxxxxxxxxxxxx>
---
Changelog v1 -> v2:
- modify the changelog
- split the old patch into two patches, this is the first one - just add
ACCESS_ONCE() wrapper.
---
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 f714379..0d88513 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 a950d48..7dbfe2c 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;
}
--
1.7.11.7
--
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