From: Jinshan Xiong <jinshan.xiong@intel.com>
Date: Thu, 3 Nov 2016 01:25:03 +0000 (-0400)
Subject: staging/lustre/llite: do not clear uptodate bit in page delete
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7995035f0df50973a15eeb69cfc02446ddacbbbc;p=linux-beck.git

staging/lustre/llite: do not clear uptodate bit in page delete

Otherwise, if the race between page fault and truncate occurs, it
will cause the page fault routine to return an EIO error.

In filemap_fault() {
    page_not_uptodate:
    ...
        ClearPageError(page);
        error = mapping->a_ops->readpage(file, page);
        if (!error) {
                wait_on_page_locked(page);
                if (!PageUptodate(page))
                        error = -EIO;
    }
    ...
}

However, I tend to think this is a defect in kernel implementation,
because it assumes PageUptodate shouldn't be cleared but file read
routine doesn't make the same assumption.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-on: http://review.whamcloud.com/22827
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8633
Reviewed-by: Li Dongyang <dongyang.li@anu.edu.au>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/lustre/lustre/llite/vvp_page.c b/drivers/staging/lustre/lustre/llite/vvp_page.c
index 25490a5188d3..23d66308ff20 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_page.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_page.c
@@ -166,7 +166,6 @@ static void vvp_page_delete(const struct lu_env *env,
 	refc = atomic_dec_return(&page->cp_ref);
 	LASSERTF(refc >= 1, "page = %p, refc = %d\n", page, refc);
 
-	ClearPageUptodate(vmpage);
 	ClearPagePrivate(vmpage);
 	vmpage->private = 0;
 	/*