[Cluster-devel] Re: [PATCH] GFS2: Use shorter form of zero_user_page() in code.

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

I just realised when I came to apply this patch that we already have
these changes in the combination of Nate Diller's patch to bmap.c and my
patch (at your suggestion) to ops_address.c so I think this is a
duplicate,

Steve.

On Tue, 2007-07-10 at 14:12 +0100, Steven Whitehouse wrote:
> Hi,
> 
> I'll add this in as soon as Linus has pulled the current tree. Thanks,
> 
> Steve.
> 
> On Tue, 2007-07-10 at 09:05 -0400, Robert P. J. Day wrote:
> > Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
> > 
> > ---
> > 
> > AFAICT, the following should be entirely equivalent, but shorter,
> > based on the zero_user_page macro defined in highmem.h.
> > 
> >  fs/gfs2/bmap.c        |    6 ++----
> >  fs/gfs2/ops_address.c |    6 ++----
> >  2 files changed, 4 insertions(+), 8 deletions(-)
> > 
> > diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
> > index c53a5d2..8fd90b3 100644
> > --- a/fs/gfs2/bmap.c
> > +++ b/fs/gfs2/bmap.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/gfs2_ondisk.h>
> >  #include <linux/crc32.h>
> >  #include <linux/lm_interface.h>
> > +#include <linux/highmem.h>
> > 
> >  #include "gfs2.h"
> >  #include "incore.h"
> > @@ -933,10 +934,7 @@ static int gfs2_block_truncate_page(struct address_space *mapping)
> >  	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
> >  		gfs2_trans_add_bh(ip->i_gl, bh, 0);
> > 
> > -	kaddr = kmap_atomic(page, KM_USER0);
> > -	memset(kaddr + offset, 0, length);
> > -	flush_dcache_page(page);
> > -	kunmap_atomic(kaddr, KM_USER0);
> > +	zero_user_page(page, offset, length, KM_USER0);
> > 
> >  unlock:
> >  	unlock_page(page);
> > diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
> > index 30c1562..d90ce06 100644
> > --- a/fs/gfs2/ops_address.c
> > +++ b/fs/gfs2/ops_address.c
> > @@ -19,6 +19,7 @@
> >  #include <linux/writeback.h>
> >  #include <linux/gfs2_ondisk.h>
> >  #include <linux/lm_interface.h>
> > +#include <linux/highmem.h>
> > 
> >  #include "gfs2.h"
> >  #include "incore.h"
> > @@ -203,10 +204,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
> >  	 * so we need to supply one here. It doesn't happen often.
> >  	 */
> >  	if (unlikely(page->index)) {
> > -		kaddr = kmap_atomic(page, KM_USER0);
> > -		memset(kaddr, 0, PAGE_CACHE_SIZE);
> > -		kunmap_atomic(kaddr, KM_USER0);
> > -		flush_dcache_page(page);
> > +		zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
> >  		SetPageUptodate(page);
> >  		return 0;
> >  	}
> > 
>