vserver 1.9.3

[linux-2.6.git] / fs / mpage.c

diff --git a/fs/mpage.c b/fs/mpage.c
index 71c7ca3..4bbf15e 100644 (file)
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -290,7 +290,8 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
 alloc_new:
        if (bio == NULL) {
                bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9),
-                                       nr_pages, GFP_KERNEL);
+                               min_t(int, nr_pages, bio_get_nr_vecs(bdev)),
+                               GFP_KERNEL);
                if (bio == NULL)
                        goto confused;
        }
@@ -627,7 +628,9 @@ mpage_writepages(struct address_space *mapping,
        struct pagevec pvec;
        int nr_pages;
        pgoff_t index;
+       pgoff_t end = -1;               /* Inclusive */
        int scanned = 0;
+       int is_range = 0;
 
        if (wbc->nonblocking && bdi_write_congested(bdi)) {
                wbc->encountered_congestion = 1;
@@ -645,9 +648,17 @@ mpage_writepages(struct address_space *mapping,
                index = 0;                        /* whole-file sweep */
                scanned = 1;
        }
+       if (wbc->start || wbc->end) {
+               index = wbc->start >> PAGE_CACHE_SHIFT;
+               end = wbc->end >> PAGE_CACHE_SHIFT;
+               is_range = 1;
+               scanned = 1;
+       }
 retry:
-       while (!done && (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
-                                       PAGECACHE_TAG_DIRTY, PAGEVEC_SIZE))) {
+       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;
 
                scanned = 1;
@@ -664,10 +675,21 @@ retry:
 
                        lock_page(page);
 
+                       if (unlikely(page->mapping != mapping)) {
+                               unlock_page(page);
+                               continue;
+                       }
+
+                       if (unlikely(is_range) && page->index > end) {
+                               done = 1;
+                               unlock_page(page);
+                               continue;
+                       }
+
                        if (wbc->sync_mode != WB_SYNC_NONE)
                                wait_on_page_writeback(page);
 
-                       if (page->mapping != mapping || PageWriteback(page) ||
+                       if (PageWriteback(page) ||
                                        !clear_page_dirty_for_io(page)) {
                                unlock_page(page);
                                continue;
@@ -706,7 +728,8 @@ retry:
                index = 0;
                goto retry;
        }
-       mapping->writeback_index = index;
+       if (!is_range)
+               mapping->writeback_index = index;
        if (bio)
                mpage_bio_submit(WRITE, bio);
        return ret;