From 3ef0f720e47e895b613b0305eb0a483e3ec11f23 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@suse.cz>
Date: Wed, 14 May 2008 16:05:37 -0700
Subject: [PATCH] mm: fix infinite loop in filemap_fault
filemap_fault will go into an infinite loop if ->readpage() fails
asynchronously.
AFAICS the bug was introduced by this commit, which removed the wait after the
final readpage:
commit d00806b183152af6d24f46f0c33f14162ca1262a
Author: Nick Piggin <npiggin@suse.de>
Date: Thu Jul 19 01:46:57 2007 -0700
mm: fix fault vs invalidate race for linear mappings
Fix by reintroducing the wait_on_page_locked() after ->readpage() to make sure
the page is up-to-date before jumping back to the beginning of the function.
I've noticed this while testing nfs exporting on fuse. The patch
fixes it.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/filemap.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/filemap.c b/mm/filemap.c
index 2dead9adf8b7..1e6a7d34874f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1461,6 +1461,11 @@ page_not_uptodate:
*/
ClearPageError(page);
error = mapping->a_ops->readpage(file, page);
+ if (!error) {
+ wait_on_page_locked(page);
+ if (!PageUptodate(page))
+ error = -EIO;
+ }
page_cache_release(page);
if (!error || error == AOP_TRUNCATED_PAGE)
--
GitLab