Messages in this thread Patch in this message | | | Date | Fri, 13 Feb 2009 16:58:28 -0800 | From | Greg KH <> | Subject | [patch 12/47] writeback: fix break condition |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
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From: Federico Cuello <fedux@lugmen.org.ar>
commit 89e1219004b3657cc014521663eeef0744f1c99d upstream.
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.
[akpm@linux-foundation.org: coding-style fixes] Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- mm/page-writeback.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-)
--- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -985,20 +985,23 @@ continue_unlock: } } - if (wbc->nr_to_write > 0) + if (wbc->nr_to_write > 0) { wbc->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 (wbc->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)) {
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