Re: [PATCH 20/30] xfs: don't block inode reclaim on the ILOCK

[Brian Foster <bfoster@redhat.com>]

On Thu, Jun 04, 2020 at 05:45:56PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> When we attempt to reclaim an inode, the first thing we do is take
> the inode lock. This is blocking right now, so if the inode being
> accessed by something else (e.g. being flushed to the cluster
> buffer) we will block here.
> 
> Change this to a trylock so that we do not block inode reclaim
> unnecessarily here.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_icache.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index c4ba8d7bc45bc..d1c47a0e0b0ec 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -1119,9 +1119,10 @@ xfs_reclaim_inode(
>  {
>  	xfs_ino_t		ino = ip->i_ino; /* for radix_tree_delete */
>  
> -	xfs_ilock(ip, XFS_ILOCK_EXCL);
> -	if (!xfs_iflock_nowait(ip))
> +	if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
>  		goto out;
> +	if (!xfs_iflock_nowait(ip))
> +		goto out_iunlock;
>  
>  	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
>  		xfs_iunpin_wait(ip);
> @@ -1188,8 +1189,9 @@ xfs_reclaim_inode(
>  
>  out_ifunlock:
>  	xfs_ifunlock(ip);
> -out:
> +out_iunlock:
>  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> +out:
>  	xfs_iflags_clear(ip, XFS_IRECLAIM);
>  	return false;
>  }
> -- 
> 2.26.2.761.g0e0b3e54be
>