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authorRik van Riel <riel@redhat.com>2011-01-14 02:46:06 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-14 04:32:35 +0300
commit212260aa07135b327752dc02625c68cf4ce04caf (patch)
tree7ea25dddf5f69e91ec4b3d22f940e6c9604c7f93
parentdabb16f639820267b3850d804571c70bd93d4e07 (diff)
downloadlinux-212260aa07135b327752dc02625c68cf4ce04caf.tar.xz
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 <riel@redhat.com> Acked-by: Valerie Aurora <vaurora@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Cc: Theodore Ts'o <tytso@mit.edu> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/page-flags.h2
-rw-r--r--mm/filemap.c2
2 files changed, 2 insertions, 2 deletions
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)
diff --git a/mm/filemap.c b/mm/filemap.c
index 1a3dd5914726..b4ad8e36c81a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -298,7 +298,7 @@ int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
continue;
wait_on_page_writeback(page);
- if (PageError(page))
+ if (TestClearPageError(page))
ret = -EIO;
}
pagevec_release(&pvec);