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| author | Nick Piggin <npiggin@suse.de> | 2009-01-07 01:39:09 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 02:58:59 +0300 |
| commit | 5a3d5c9813db56a75934eb1015367fda23a8b0b4 (patch) | |
| tree | 656b43b3982a6513467e9a3191377429bb9f45f1 /mm/page-writeback.c | |
| parent | 05fe478dd04e02fa230c305ab9b5616669821dd3 (diff) | |
| download | linux-5a3d5c9813db56a75934eb1015367fda23a8b0b4.tar.xz | |
mm: write_cache_pages cleanups
Get rid of some complex expressions from flow control statements, add a
comment, remove some duplicate code.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 5edca676e2c3..c3fb38b1ea43 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -899,11 +899,14 @@ int write_cache_pages(struct address_space *mapping, } 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)) { |