lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <E1J8UbJ-0007Be-E3@localhost>
Date:	Sat, 29 Dec 2007 13:51:13 +0800
From:	Fengguang Wu <wfg@...l.ustc.edu.cn>
To:	Dave Kleikamp <shaggy@...ux.vnet.ibm.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	jfs-discussion@...ts.sourceforge.net,
	Nick Piggin <nickpiggin@...oo.com.au>
Subject: Re: [PATCH] jfs: clear PAGECACHE_TAG_DIRTY for no-write pages

On Fri, Dec 28, 2007 at 10:50:59PM -0600, Dave Kleikamp wrote:
> 
> On Sat, 2007-12-29 at 10:21 +0800, Fengguang Wu wrote:
> > On Fri, Dec 28, 2007 at 10:53:14AM -0600, Dave Kleikamp wrote:
> > 
> > 
> > > ---
> > > 
> > > diff -Nurp linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c linux/fs/jfs/jfs_metapage.c
> > > --- linux-2.6.24-rc6-git5/fs/jfs/jfs_metapage.c	2007-12-28 10:28:33.000000000 -0600
> > > +++ linux/fs/jfs/jfs_metapage.c	2007-12-28 10:37:30.000000000 -0600
> > > @@ -360,6 +360,7 @@ static int metapage_writepage(struct pag
> > >  	struct metapage *mp;
> > >  	int redirty = 0;
> > >  	sector_t lblock;
> > > +	int nr_underway = 0;
> > >  	sector_t pblock;
> > >  	sector_t next_block = 0;
> > >  	sector_t page_start;
> > > @@ -371,6 +372,7 @@ static int metapage_writepage(struct pag
> > >  		     (PAGE_CACHE_SHIFT - inode->i_blkbits);
> > >  	BUG_ON(!PageLocked(page));
> > >  	BUG_ON(PageWriteback(page));
> > 
> > This line should be moved below:
> > > +	set_page_writeback(page);
> 
> No.  set_page_writeback() needs to be called before submit_bio() is
> called.

Ah yes.

> I don't think there is any harm in calling set_page_writeback(),
> redirty_page_for_writeback() and end_page_writeback() in the case where
> there is no I/O to submit, and some dirty data cannot be written.  It is
> consistent with what happens in __block_write_full_page().
> 
> It's also possible that some part of the page was written, and another
> part cannot be, causing the page to be redirtied.

You are right. I revisited the code and there's nothing wrong with
your patch :-)

Regards,
Fengguang

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ