Re: [PATCH 5/9] xfs: fix double ijoin in xfs_inactive_symlink_rmt()

[Brian Foster <bfoster@redhat.com>]

On Tue, May 08, 2018 at 01:41:58PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> xfs_inactive_symlink_rmt() does something nasty - it joins an inode
> into a transaction it is already joined to. This means the inode can
> have multiple log item descriptors attached to the transaction for
> it. This breaks teh 1:1 mapping that is supposed to exist
> between the log item and log item descriptor.
> 
> This results in the log item being processed twice during
> transaction commit and CIL formatting, and there are lots of other
> potential issues tha arise from double processing of log items in
> the transaction commit state machine.
> 
> In this case, the inode is already held by the rolling transaction
> returned from xfs_defer_finish(), so there's no need to join it
> again.
> 
> Signed-Off-By: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_symlink.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
> index 5b66ac12913c..27870e5cd259 100644
> --- a/fs/xfs/xfs_symlink.c
> +++ b/fs/xfs/xfs_symlink.c
> @@ -488,16 +488,11 @@ xfs_inactive_symlink_rmt(
>  	error = xfs_defer_finish(&tp, &dfops);
>  	if (error)
>  		goto error_bmap_cancel;
> -	/*
> -	 * The first xact was committed, so add the inode to the new one.
> -	 * Mark it dirty so it will be logged and moved forward in the log as
> -	 * part of every commit.
> -	 */
> -	xfs_trans_ijoin(tp, ip, 0);
> -	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
> +
>  	/*
>  	 * Commit the transaction containing extent freeing and EFDs.
>  	 */
> +	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

Seems fine.. but do we even need this call? We're about to commit the
transaction and unlock the inode...

Brian

>  	error = xfs_trans_commit(tp);
>  	if (error) {
>  		ASSERT(XFS_FORCED_SHUTDOWN(mp));
> -- 
> 2.17.0
> 
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