Commit af6f029d authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: Use tag dirty lookup during mpage_da_submit_io 



This enables us to drop the range_cont writeback mode
use from ext4_da_writepages.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
parent 8a0aba73

fs/ext4/inode.c

+13 −17
Original line number Diff line number Diff line
@@ -1656,17 +1656,23 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd) 


	while (index <= end) {

		/* XXX: optimize tail */

		nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);

		/*

		 * We can use PAGECACHE_TAG_DIRTY lookup here because

		 * even though we have cleared the dirty flag on the page

		 * We still keep the page in the radix tree with tag

		 * PAGECACHE_TAG_DIRTY. See clear_page_dirty_for_io.

		 * The PAGECACHE_TAG_DIRTY is cleared in set_page_writeback

		 * which is called via the below writepage callback.

		 */

		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];



			index = page->index;

			if (index > end)

				break;

			index++;



			err = mapping->a_ops->writepage(page, mpd->wbc);

			if (!err)

				mpd->pages_written++;
@@ -2361,7 +2367,6 @@ static int ext4_da_writepages(struct address_space *mapping, 
			      struct writeback_control *wbc)

{

	handle_t *handle = NULL;

	loff_t range_start = 0;

	struct mpage_da_data mpd;

	struct inode *inode = mapping->host;

	int needed_blocks, ret = 0, nr_to_writebump = 0;
@@ -2386,14 +2391,7 @@ static int ext4_da_writepages(struct address_space *mapping, 
		wbc->nr_to_write = sbi->s_mb_stream_request;

	}



	if (!wbc->range_cyclic)

		/*

		 * If range_cyclic is not set force range_cont

		 * and save the old writeback_index

		 */

		wbc->range_cont = 1;



	range_start =  wbc->range_start;

	pages_skipped = wbc->pages_skipped;



	mpd.wbc = wbc;
@@ -2452,9 +2450,8 @@ static int ext4_da_writepages(struct address_space *mapping, 
		wbc->nr_to_write = to_write;

	}



	if (wbc->range_cont && (pages_skipped != wbc->pages_skipped)) {

	if (!wbc->range_cyclic && (pages_skipped != wbc->pages_skipped)) {

		/* We skipped pages in this loop */

		wbc->range_start = range_start;

		wbc->nr_to_write = to_write +

				wbc->pages_skipped - pages_skipped;

		wbc->pages_skipped = pages_skipped;
@@ -2463,7 +2460,6 @@ static int ext4_da_writepages(struct address_space *mapping, 


out_writepages:

	wbc->nr_to_write = to_write - nr_to_writebump;

	wbc->range_start = range_start;

	return ret;

}