The patch titled
writeback: fix break condition
has been added to the -mm tree. Its filename is
writeback-fix-break-condition.patch
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------------------------------------------------------
Subject: writeback: fix break condition
From: Federico Cuello <fedux@xxxxxxxxxxxxx>
Commit dcf6a79dda5cc2a2bec183e50d829030c0972aaa ("write-back: fix
nr_to_write counter") fixed nr_to_write counter, but didn't set the break
condition properly.
If nr_to_write == 0 after being decremented it will loop one more time
before setting done = 1 and breaking the loop.
Cc: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff -puN mm/page-writeback.c~writeback-fix-break-condition mm/page-writeback.c
--- a/mm/page-writeback.c~writeback-fix-break-condition
+++ a/mm/page-writeback.c
@@ -1051,20 +1051,21 @@ continue_unlock:
}
}
- if (nr_to_write > 0)
+ if (nr_to_write > 0) {
nr_to_write--;
- else if (wbc->sync_mode == WB_SYNC_NONE) {
- /*
- * We stop writing back only if we are not
- * doing integrity sync. In case of integrity
- * sync we have to keep going because someone
- * may be concurrently dirtying pages, and we
- * might have synced a lot of newly appeared
- * dirty pages, but have not synced all of the
- * old dirty pages.
- */
- done = 1;
- break;
+ if (nr_to_write == 0 && wbc->sync_mode == WB_SYNC_NONE) {
+ /*
+ * We stop writing back only if we are not
+ * doing integrity sync. In case of integrity
+ * sync we have to keep going because someone
+ * may be concurrently dirtying pages, and we
+ * might have synced a lot of newly appeared
+ * dirty pages, but have not synced all of the
+ * old dirty pages.
+ */
+ done = 1;
+ break;
+ }
}
if (wbc->nonblocking && bdi_write_congested(bdi)) {
_
Patches currently in -mm which might be from fedux@xxxxxxxxxxxxx are
writeback-fix-break-condition.patch
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