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Date:   Tue, 21 Apr 2020 14:15:53 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     "Darrick J. Wong" <darrick.wong@oracle.com>
Cc:     linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
        Al Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Chinner <david@fromorbit.com>,
        Christoph Hellwig <hch@lst.de>,
        "Theodore Y. Ts'o" <tytso@mit.edu>, Jeff Moyer <jmoyer@redhat.com>,
        linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH V9 09/11] fs: Introduce DCACHE_DONTCACHE
Message-ID: <20200421211553.GC3372712@iweiny-DESK2.sc.intel.com>
References: <20200421191754.3372370-1-ira.weiny@intel.com>
 <20200421191754.3372370-10-ira.weiny@intel.com>
 <20200421202519.GC6742@magnolia>
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On Tue, Apr 21, 2020 at 01:25:19PM -0700, Darrick J. Wong wrote:
> On Tue, Apr 21, 2020 at 12:17:51PM -0700, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > DCACHE_DONTCACHE indicates a dentry should not be cached on final
> > dput().
> > 
> > Also add a helper function to mark DCACHE_DONTCACHE on all dentries
> > pointing to a specific inode when that inode is being set I_DONTCACHE.
> > 
> > This facilitates dropping dentry references to inodes sooner which
> > require eviction to swap S_DAX mode.
> > 
> > Cc: Al Viro <viro@zeniv.linux.org.uk>
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---

[snip]

> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index de76f7f60695..3c8f44477804 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> > @@ -559,7 +559,7 @@ xfs_iget_cache_miss(
> >  	 */
> >  	iflags = XFS_INEW;
> >  	if (flags & XFS_IGET_DONTCACHE)
> > -		VFS_I(ip)->i_state |= I_DONTCACHE;
> > +		mark_inode_dontcache(VFS_I(ip));
> >  	ip->i_udquot = NULL;
> >  	ip->i_gdquot = NULL;
> >  	ip->i_pdquot = NULL;
> > diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> > index c1488cc84fd9..56b1482d9223 100644
> > --- a/include/linux/dcache.h
> > +++ b/include/linux/dcache.h
> > @@ -177,6 +177,8 @@ struct dentry_operations {
> >  
> >  #define DCACHE_REFERENCED		0x00000040 /* Recently used, don't discard. */
> >  
> > +#define DCACHE_DONTCACHE		0x00000080 /* don't cache on final dput() */
> 
> "Purge from memory on final dput()"?

Sounds good to me,
Ira

> 
> --D
>