[PATCH v2] xfs: fix unlock in xfs_bmap_add_attrfork

[Mark Tinguely]

On 11/06/13 16:41, Dave Chinner wrote:
> On Wed, Nov 06, 2013 at 03:14:58PM -0600, Mark Tinguely wrote:
>> xfs_trans_ijoin() activates the inode in a transaction and
>> also can specify which lock to free when the transaction is
>> committed or canceled.
>>
>> xfs_bmap_add_attrfork call locks and add the lock to the
>> transaction but also manually removes the lock. Change the
>> routine to not add the lock to the transaction and manually
>> remove lock on completion.
>>
>> While here, clean up the xfs_trans_cancel flags and goto names.
>>
>> Signed-off-by: Mark Tinguely<tinguely at sgi.com>
>
> All good, except for:
>

...

>
> This hunk. It ends up looking like this:
>
> 	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
> 	goto unlock_return;
> bmap_cancel:
> 	xfs_bmap_cancel(&flist);
> trans_cancel:
> 	xfs_trans_cancel(tp, cancel_flags);
> unlock_return:
> 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> 	return error;
> }
>
> Which jumps over error handling cases on a successful completion.
> The conventional way of doing this is having the successful return
> case run straight through to the return, and having the error stack
> either jump back into it like so:
>
> 	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
> unlock_return:
> 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> 	return error;
>
> bmap_cancel:
> 	xfs_bmap_cancel(&flist);
> trans_cancel:
> 	xfs_trans_cancel(tp, cancel_flags);
> 	goto unlock_return;
> }
>
> or do an additional unlock and return directly in the error stack
> and let the compiler optimise it appropriately.
>
> Cheers,
>
> Dave.

Thanks for catching that.

--Mark.