From: Steven Whitehouse <swhiteho@redhat.com>
Subject: [RHEL5] bz 218966 Readpages fix [1/4]
Date: Fri, 15 Dec 2006 17:46:28 +0000
Bugzilla: 218966
Message-Id: <1166204788.3752.1252.camel@quoit.chygwyn.com>
Changelog: gfs2: Readpages fix 


Hi,

This is the first of four patches to fix bz #218966. It also as a side
effect (just this first patch) fixes bz #219131 (relating to CIFS, the
remaining patch for this bug isn't required to fix the bug, but is a
cleanup from upstream and its also not part of this patch series). This
patch is already upstream and has been for some time. Its a one-liner
change to read_pages() to ensure that all the pages which ->readpages()
is called with are suitable disposed of in the case that ->readpages()
fails to do it correctly itself. This is the only change in the patch
series outside of GFS2's own code.

Since most of the implementations of ->readpages() do correctly deal
with this case, it becomes a no-op. In the upstream code, its now
assumed that read_pages() will correctly dispose of any unused pages
rather than leaving it to ->readpages().

As a set all four patches are upstream (the final one is only in the
-nmw GFS2 git tree, but the other three have been upstream for some time
now) and we've verified that the truncate test mentioned in bz #218966
is passed with these patches applied.

Steve.


X-Git-Tag: v2.6.19-rc5
X-Git-Url: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=029e332ea717810172e965ec50f942755ad0c58a

[PATCH] Cleanup read_pages()

Current read_pages() assume ->readpages() frees the passed pages.

This patch free the pages in ->read_pages(), if those were remaining in the
pages_list.  So, readpages() just can ignore the remaining pages in
pages_list.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -173,6 +173,8 @@ static int read_pages(struct address_spa
 
 	if (mapping->a_ops->readpages) {
 		ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
+		/* Clean up the remaining pages */
+		put_pages_list(pages);
 		goto out;
 	}