From 212260aa07135b327752dc02625c68cf4ce04caf Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Thu, 13 Jan 2011 15:46:06 -0800 Subject: mm: clear PageError bit in msync & fsync Temporary IO failures, eg. due to loss of both multipath paths, can permanently leave the PageError bit set on a page, resulting in msync or fsync returning -EIO over and over again, even if IO is now getting to the disk correctly. We already clear the AS_ENOSPC and AS_IO bits in mapping->flags in the filemap_fdatawait_range function. Also clearing the PageError bit on the page allows subsequent msync or fsync calls on this file to return without an error, if the subsequent IO succeeds. Unfortunately data written out in the msync or fsync call that returned -EIO can still get lost, because the page dirty bit appears to not get restored on IO error. However, the alternative could be potentially all of memory filling up with uncleanable dirty pages, hanging the system, so there is no nice choice here... Signed-off-by: Rik van Riel Acked-by: Valerie Aurora Acked-by: Jeff Layton Cc: Theodore Ts'o Acked-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 5f38c460367e..4805fdec8d6e 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -198,7 +198,7 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; } struct page; /* forward declaration */ TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked) -PAGEFLAG(Error, error) +PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error) PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced) PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty) PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru) -- cgit v1.2.1