[PATCH v2 06/17] mm: doc comment for scary spot in write_one_page

From: Jeff Layton <jlayton@redhat.com>
To: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
	tytso@mit.edu, jack@suse.cz, willy@infradead.org, neilb@suse.com,
	viro@zeniv.linux.org.uk
Subject: [PATCH v2 06/17] mm: doc comment for scary spot in write_one_page
Date: Wed, 12 Apr 2017 08:06:03 -0400	[thread overview]
Message-ID: <20170412120614.6111-7-jlayton@redhat.com> (raw)
In-Reply-To: <20170412120614.6111-1-jlayton@redhat.com>

Not sure what to do here just yet.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 mm/page-writeback.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index de0dbf12e2c1..3ac8399dc984 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2388,6 +2388,12 @@ int write_one_page(struct page *page)
 		ret = mapping->a_ops->writepage(page, &wbc);
 		if (ret == 0) {
 			wait_on_page_writeback(page);
+			/*
+			 * FIXME: is this racy? What guarantees that PG_error
+			 * will still be set once we get around to checking it?
+			 * What if writeback fails, but then a read is issued
+			 * before we check this, and that calls ClearPageError?
+			 */
 			if (PageError(page))
 				ret = -EIO;
 		}
-- 
2.9.3
