From: Matthew Wilcox <willy@infradead.org>
To: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Dave Chinner <david@fromorbit.com>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC v2 2/2] gfs2: Rework read and page fault locking
Date: Fri, 3 Jul 2020 12:44:37 +0100 [thread overview]
Message-ID: <20200703114437.GF25523@casper.infradead.org> (raw)
In-Reply-To: <20200703113801.GD25523@casper.infradead.org>
On Fri, Jul 03, 2020 at 12:38:01PM +0100, Matthew Wilcox wrote:
> > @@ -598,16 +562,9 @@ static void gfs2_readahead(struct readahead_control *rac)
> > {
> > struct inode *inode = rac->mapping->host;
> > struct gfs2_inode *ip = GFS2_I(inode);
> > - struct gfs2_holder gh;
> >
> > - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
> > - if (gfs2_glock_nq(&gh))
> > - goto out_uninit;
> > if (!gfs2_is_stuffed(ip))
> > mpage_readahead(rac, gfs2_block_map);
>
> I think you probably want to make this:
>
> if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
> !page_has_buffers(page))
> error = iomap_readahead(rac, &gfs2_iomap_ops);
> else if (!gfs2_is_stuffed(ip))
> error = mpage_readahead(rac, gfs2_block_map);
>
> ... but I understand not wanting to make that change at this point
> in the release cycle.
That was stupid. I meant to write out:
if (i_blocksize(rac->mapping->host) == PAGE_SIZE)
error = iomap_readahead(rac, &gfs2_iomap_ops);
else if (!gfs2_is_stuffed(ip))
error = mpage_readahead(rac, gfs2_block_map);
Since the pages are freshly allocated, they can't have buffers, and
the mapping comes out of the readahead_control, not from the page.
next prev parent reply other threads:[~2020-07-03 11:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-03 9:53 [RFC v2 0/2] Fix gfs2 readahead deadlocks Andreas Gruenbacher
2020-07-03 9:53 ` [RFC v2 1/2] fs: Add IOCB_NOIO flag for generic_file_read_iter Andreas Gruenbacher
2020-07-03 11:41 ` Matthew Wilcox
2020-07-05 15:08 ` Andreas Gruenbacher
2020-07-03 9:53 ` [RFC v2 2/2] gfs2: Rework read and page fault locking Andreas Gruenbacher
2020-07-03 11:38 ` Matthew Wilcox
2020-07-03 11:44 ` Matthew Wilcox [this message]
2020-07-03 19:24 ` [RFC v2 0/2] Fix gfs2 readahead deadlocks Linus Torvalds
2020-07-03 19:26 ` Linus Torvalds
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