The patch titled
mm: clear PageError bit in msync & fsync
has been added to the -mm tree. Its filename is
mm-clear-pageerror-bit-in-msync-fsync.patch
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------------------------------------------------------
Subject: mm: clear PageError bit in msync & fsync
From: Rik van Riel <riel@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Valerie Aurora <vaurora@xxxxxxxxxx>
Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Acked-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 2 +-
mm/filemap.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff -puN include/linux/page-flags.h~mm-clear-pageerror-bit-in-msync-fsync include/linux/page-flags.h
--- a/include/linux/page-flags.h~mm-clear-pageerror-bit-in-msync-fsync
+++ a/include/linux/page-flags.h
@@ -198,7 +198,7 @@ static inline int __TestClearPage##uname
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 -puN mm/filemap.c~mm-clear-pageerror-bit-in-msync-fsync mm/filemap.c
--- a/mm/filemap.c~mm-clear-pageerror-bit-in-msync-fsync
+++ a/mm/filemap.c
@@ -307,7 +307,7 @@ int filemap_fdatawait_range(struct addre
continue;
wait_on_page_writeback(page);
- if (PageError(page))
+ if (TestClearPageError(page))
ret = -EIO;
}
pagevec_release(&pvec);
_
Patches currently in -mm which might be from riel@xxxxxxxxxx are
linux-next.patch
writeback-io-less-balance_dirty_pages.patch
writeback-consolidate-variable-names-in-balance_dirty_pages.patch
writeback-per-task-rate-limit-on-balance_dirty_pages.patch
writeback-per-task-rate-limit-on-balance_dirty_pages-fix.patch
writeback-prevent-duplicate-balance_dirty_pages_ratelimited-calls.patch
writeback-account-per-bdi-accumulated-written-pages.patch
writeback-bdi-write-bandwidth-estimation.patch
writeback-bdi-write-bandwidth-estimation-fix.patch
writeback-show-bdi-write-bandwidth-in-debugfs.patch
writeback-quit-throttling-when-bdi-dirty-pages-dropped-low.patch
writeback-reduce-per-bdi-dirty-threshold-ramp-up-time.patch
writeback-make-reasonable-gap-between-the-dirty-background-thresholds.patch
writeback-scale-down-max-throttle-bandwidth-on-concurrent-dirtiers.patch
writeback-add-trace-event-for-balance_dirty_pages.patch
writeback-make-nr_to_write-a-per-file-limit.patch
writeback-make-nr_to_write-a-per-file-limit-fix.patch
mm-compaction-add-trace-events-for-memory-compaction-activity.patch
mm-vmscan-convert-lumpy_mode-into-a-bitmask.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path.patch
mm-migration-cleanup-migrate_pages-api-by-matching-types-for-offlining-and-sync.patch
mm-compaction-perform-a-faster-migration-scan-when-migrating-asynchronously.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode.patch
mm-deactivate-invalidated-pages.patch
mm-deactivate-invalidated-pages-fix.patch
oom-allow-a-non-cap_sys_resource-proces-to-oom_score_adj-down.patch
mm-clear-pageerror-bit-in-msync-fsync.patch
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