From 139c793b0c742110966f2dbfd4a8677c3bf48a49 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Wed, 26 May 2010 11:49:40 -0400 Subject: do_generic_file_read: clear page errors when issuing a fresh read of the page commit 91803b499cca2fe558abad709ce83dc896b80950 upstream. I/O errors can happen due to temporary failures, like multipath errors or losing network contact with the iSCSI server. Because of that, the VM will retry readpage on the page. However, do_generic_file_read does not clear PG_error. This causes the system to be unable to actually use the data in the page cache page, even if the subsequent readpage completes successfully! The function filemap_fault has had a ClearPageError before readpage forever. This patch simply adds the same to do_generic_file_read. Signed-off-by: Jeff Moyer Signed-off-by: Rik van Riel Acked-by: Larry Woodman Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/filemap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 3dce0107262..96398d397e7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1099,6 +1099,12 @@ page_not_up_to_date_locked: } readpage: + /* + * A previous I/O error may have been due to temporary + * failures, eg. multipath errors. + * PG_error will be set again if readpage fails. + */ + ClearPageError(page); /* Start the actual read. The read will unlock the page. */ error = mapping->a_ops->readpage(filp, page); -- cgit