The patch titled
mm: write_cache_pages cleanups
has been added to the -mm tree. Its filename is
mm-write_cache_pages-cleanups.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: write_cache_pages cleanups
From: Nick Piggin <npiggin@xxxxxxx>
Get rid of some complex expressions from flow control statements, add a
comment, remove some duplicate code.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: jim owens <jowens@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff -puN mm/page-writeback.c~mm-write_cache_pages-cleanups mm/page-writeback.c
--- a/mm/page-writeback.c~mm-write_cache_pages-cleanups
+++ a/mm/page-writeback.c
@@ -899,11 +899,14 @@ int write_cache_pages(struct address_spa
}
retry:
done_index = index;
- while (!done && (index <= end) &&
- (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
- PAGECACHE_TAG_DIRTY,
- min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
- unsigned i;
+ while (!done && (index <= end)) {
+ int i;
+
+ nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+ PAGECACHE_TAG_DIRTY,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+ if (nr_pages == 0)
+ break;
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];
@@ -919,7 +922,16 @@ retry:
*/
lock_page(page);
+ /*
+ * Page truncated or invalidated. We can freely skip it
+ * then, even for data integrity operations: the page
+ * has disappeared concurrently, so there could be no
+ * real expectation of this data interity operation
+ * even if there is now a new, dirty page at the same
+ * pagecache address.
+ */
if (unlikely(page->mapping != mapping)) {
+continue_unlock:
unlock_page(page);
continue;
}
@@ -930,18 +942,15 @@ retry:
* end == -1 in that case.
*/
done = 1;
- unlock_page(page);
- continue;
+ goto continue_unlock;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) ||
- !clear_page_dirty_for_io(page)) {
- unlock_page(page);
- continue;
- }
+ !clear_page_dirty_for_io(page))
+ goto continue_unlock;
ret = (*writepage)(page, wbc, data);
if (unlikely(ret)) {
@@ -964,7 +973,8 @@ retry:
}
if (wbc->sync_mode == WB_SYNC_NONE) {
- if (--wbc->nr_to_write <= 0)
+ wbc->nr_to_write--;
+ if (wbc->nr_to_write <= 0)
done = 1;
}
if (wbc->nonblocking && bdi_write_congested(bdi)) {
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
mm-increase-the-default-mlock-limit-from-32k-to-64k.patch
fs-remove-prepare_write-commit_write.patch
linux-next.patch
mm-dont-mark_page_accessed-in-fault-path.patch
mm-invoke-oom-killer-from-page-fault.patch
mm-invoke-oom-killer-from-page-fault-fix.patch
mm-invoke-oom-killer-from-page-fault-fix-fix-2.patch
mm-write_cache_pages-cyclic-fix.patch
mm-write_cache_pages-cyclic-fix-fix.patch
mm-write_cache_pages-early-loop-termination.patch
mm-write_cache_pages-writepage-error-fix.patch
mm-write_cache_pages-integrity-fix.patch
mm-write_cache_pages-cleanups.patch
mm-write_cache_pages-optimise-page-cleaning.patch
mm-write_cache_pages-terminate-quickly.patch
mm-write_cache_pages-more-terminate-quickly.patch
mm-do_sync_mapping_range-integrity-fix.patch
reiser4.patch
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