[PATCH] do_generic_file_read: clear page errors when issuing a fresh read of the page
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From: Rik van Riel on 26 May 2010 12:00 From: Jeff Moyer <jmoyer(a)redhat.com> 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: Rik van Riel <riel(a)redhat.com> Signed-off-by: Jeff Moyer <jmoyer(a)redhat.com> --- mm/filemap.c | 6 ++++++ 1 file changed, 6 insertions(+) Index: linux-2.6.34/mm/filemap.c =================================================================== --- linux-2.6.34.orig/mm/filemap.c +++ linux-2.6.34/mm/filemap.c @@ -1106,6 +1106,12 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |