From: Filipe Manana fdmanana@suse.com
commit b28ff3a7d7e97456fd86b68d24caa32e1cfa7064 upstream.
btrfs_attach_transaction_barrier() is used to get a handle pointing to the current running transaction if the transaction has not started its commit yet (its state is < TRANS_STATE_COMMIT_START). If the transaction commit has started, then we wait for the transaction to commit and finish before returning - however we completely ignore if the transaction was aborted due to some error during its commit, we simply return ERR_PT(-ENOENT), which makes the caller assume everything is fine and no errors happened.
This could make an fsync return success (0) to user space when in fact we had a transaction abort and the target inode changes were therefore not persisted.
Fix this by checking for the return value from btrfs_wait_for_commit(), and if it returned an error, return it back to the caller.
Fixes: d4edf39bd5db ("Btrfs: fix uncompleted transaction") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/transaction.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -821,8 +821,13 @@ btrfs_attach_transaction_barrier(struct
trans = start_transaction(root, 0, TRANS_ATTACH, BTRFS_RESERVE_NO_FLUSH, true); - if (trans == ERR_PTR(-ENOENT)) - btrfs_wait_for_commit(root->fs_info, 0); + if (trans == ERR_PTR(-ENOENT)) { + int ret; + + ret = btrfs_wait_for_commit(root->fs_info, 0); + if (ret) + return ERR_PTR(ret); + }
return trans; }