Re: [PATCH V6 1/8] fs/xfs: Remove unnecessary initialization of i_rwsem

From: Dave Chinner <david@fromorbit.com>
To: ira.weiny@intel.com
Cc: linux-kernel@vger.kernel.org,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	"Theodore Y. Ts'o" <tytso@mit.edu>, Jan Kara <jack@suse.cz>,
	Jeff Moyer <jmoyer@redhat.com>,
	linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH V6 1/8] fs/xfs: Remove unnecessary initialization of i_rwsem
Date: Wed, 8 Apr 2020 09:46:21 +1000	[thread overview]
Message-ID: <20200407234621.GD24067@dread.disaster.area> (raw)
In-Reply-To: <20200407182958.568475-2-ira.weiny@intel.com>

On Tue, Apr 07, 2020 at 11:29:51AM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> An earlier call of xfs_reinit_inode() from xfs_iget_cache_hit() already
> handles initialization of i_rwsem.
> 
> Doing so again is unneeded.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
> ---
> Changes from V4:
> 	Update commit message to make it clear the xfs_iget_cache_hit()
> 	is actually doing the initialization via xfs_reinit_inode()
> 
> New for V4:
> 
> NOTE: This was found while ensuring the new i_aops_sem was properly
> handled.  It seems like this is a layering violation so I think it is
> worth cleaning up so as to not confuse others.
> ---
>  fs/xfs/xfs_icache.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 8dc2e5414276..836a1f09be03 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -419,6 +419,7 @@ xfs_iget_cache_hit(
>  		spin_unlock(&ip->i_flags_lock);
>  		rcu_read_unlock();
>  
> +		ASSERT(!rwsem_is_locked(&inode->i_rwsem));
>  		error = xfs_reinit_inode(mp, inode);
>  		if (error) {
>  			bool wake;
> @@ -452,9 +453,6 @@ xfs_iget_cache_hit(
>  		ip->i_sick = 0;
>  		ip->i_checked = 0;
>  
> -		ASSERT(!rwsem_is_locked(&inode->i_rwsem));
> -		init_rwsem(&inode->i_rwsem);
> -
>  		spin_unlock(&ip->i_flags_lock);
>  		spin_unlock(&pag->pag_ici_lock);
>  	} else {

Looks good.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
-- 
Dave Chinner
david@fromorbit.com