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Commit 791b7f08 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: Fix the delalloc writepages to allocate blocks at the right offset. 



When iterating through the pages which have mapped buffer_heads, we
failed to update the b_state value. This results in allocating blocks
at logical offset 0.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
parent 2a21e37e

fs/ext4/inode.c

+39 −17
Original line number Original line Diff line number Diff line
@@ -1653,35 +1653,39 @@ struct mpage_da_data { 
 */

 */

static int mpage_da_submit_io(struct mpage_da_data *mpd)

static int mpage_da_submit_io(struct mpage_da_data *mpd)

{

{

	struct address_space *mapping = mpd->inode->i_mapping;

	int ret = 0, err, nr_pages, i;

	unsigned long index, end;

	struct pagevec pvec;

	long pages_skipped;

	long pages_skipped;

	struct pagevec pvec;

	unsigned long index, end;

	int ret = 0, err, nr_pages, i;

	struct inode *inode = mpd->inode;

	struct address_space *mapping = inode->i_mapping;





	BUG_ON(mpd->next_page <= mpd->first_page);

	BUG_ON(mpd->next_page <= mpd->first_page);

	pagevec_init(&pvec, 0);

	/*

	 * We need to start from the first_page to the next_page - 1

	 * to make sure we also write the mapped dirty buffer_heads.

	 * If we look at mpd->lbh.b_blocknr we would only be looking

	 * at the currently mapped buffer_heads.

	 */

	index = mpd->first_page;

	index = mpd->first_page;

	end = mpd->next_page - 1;

	end = mpd->next_page - 1;





	pagevec_init(&pvec, 0);

	while (index <= end) {

	while (index <= end) {

		/*

		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)

		if (nr_pages == 0)

			break;

			break;

		for (i = 0; i < nr_pages; i++) {

		for (i = 0; i < nr_pages; i++) {

			struct page *page = pvec.pages[i];

			struct page *page = pvec.pages[i];





			index = page->index;

			if (index > end)

				break;

			index++;



			BUG_ON(!PageLocked(page));

			BUG_ON(PageWriteback(page));



			pages_skipped = mpd->wbc->pages_skipped;

			pages_skipped = mpd->wbc->pages_skipped;

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

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

			if (!err && (pages_skipped == mpd->wbc->pages_skipped))

			if (!err && (pages_skipped == mpd->wbc->pages_skipped))
@@ -2095,11 +2099,29 @@ static int __mpage_da_writepage(struct page *page, 
		bh = head;

		bh = head;

		do {

		do {

			BUG_ON(buffer_locked(bh));

			BUG_ON(buffer_locked(bh));

			/*

			 * We need to try to allocate

			 * unmapped blocks in the same page.

			 * Otherwise we won't make progress

			 * with the page in ext4_da_writepage

			 */

			if (buffer_dirty(bh) &&

			if (buffer_dirty(bh) &&

				(!buffer_mapped(bh) || buffer_delay(bh))) {

				(!buffer_mapped(bh) || buffer_delay(bh))) {

				mpage_add_bh_to_extent(mpd, logical, bh);

				mpage_add_bh_to_extent(mpd, logical, bh);

				if (mpd->io_done)

				if (mpd->io_done)

					return MPAGE_DA_EXTENT_TAIL;

					return MPAGE_DA_EXTENT_TAIL;

			} else if (buffer_dirty(bh) && (buffer_mapped(bh))) {

				/*

				 * mapped dirty buffer. We need to update

				 * the b_state because we look at

				 * b_state in mpage_da_map_blocks. We don't

				 * update b_size because if we find an

				 * unmapped buffer_head later we need to

				 * use the b_state flag of that buffer_head.

				 */

				if (mpd->lbh.b_size == 0)

					mpd->lbh.b_state =

						bh->b_state & BH_FLAGS;

			}

			}

			logical++;

			logical++;

		} while ((bh = bh->b_this_page) != head);

		} while ((bh = bh->b_this_page) != head);