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Commit 65c4db8c authored by Ryan Ding's avatar Ryan Ding Committed by Linus Torvalds
Browse files

ocfs2: test target page before change it 



To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

Direct io data will not appear in buffer.  The w_target_page member will
not be filled by direct io.  So avoid to use it when it's NULL.  Unlinke
buffer io and mmap, direct io will call write_begin with more than 1
page a time.  So the target_index is not sufficient to describe the
actual data.  change it to a range start at target_index, end in
end_index.

Signed-off-by: default avatarRyan Ding <ryan.ding@oracle.com>
Reviewed-by: default avatarJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b46637d5

fs/ocfs2/aops.c

+26 −6
Original line number Diff line number Diff line
@@ -1406,12 +1406,13 @@ static void ocfs2_write_failure(struct inode *inode, 
		to = user_pos + user_len;

	struct page *tmppage;



	if (wc->w_target_page)

		ocfs2_zero_new_buffers(wc->w_target_page, from, to);



	for(i = 0; i < wc->w_num_pages; i++) {

		tmppage = wc->w_pages[i];



		if (page_has_buffers(tmppage)) {

		if (tmppage && page_has_buffers(tmppage)) {

			if (ocfs2_should_order_data(inode))

				ocfs2_jbd2_file_inode(wc->w_handle, inode);
@@ -1541,11 +1542,13 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, 
		wc->w_num_pages = 1;

		start = target_index;

	}

	end_index = (user_pos + user_len - 1) >> PAGE_CACHE_SHIFT;



	for(i = 0; i < wc->w_num_pages; i++) {

		index = start + i;



		if (index == target_index && mmap_page) {

		if (index >= target_index && index <= end_index &&

		    wc->w_type == OCFS2_WRITE_MMAP) {

			/*

			 * ocfs2_pagemkwrite() is a little different

			 * and wants us to directly use the page
@@ -1564,6 +1567,11 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, 
			page_cache_get(mmap_page);

			wc->w_pages[i] = mmap_page;

			wc->w_target_locked = true;

		} else if (index >= target_index && index <= end_index &&

			   wc->w_type == OCFS2_WRITE_DIRECT) {

			/* Direct write has no mapping page. */

			wc->w_pages[i] = NULL;

			continue;

		} else {

			wc->w_pages[i] = find_or_create_page(mapping, index,

							     GFP_NOFS);
@@ -1665,6 +1673,12 @@ static int ocfs2_write_cluster(struct address_space *mapping, 
	for(i = 0; i < wc->w_num_pages; i++) {

		int tmpret;



		/* This is the direct io target page. */

		if (wc->w_pages[i] == NULL) {

			p_blkno++;

			continue;

		}



		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,

						      wc->w_pages[i], cpos,

						      user_pos, user_len,
@@ -2266,6 +2280,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
		ocfs2_free_alloc_context(meta_ac);



success:

	if (pagep)

		*pagep = wc->w_target_page;

	*fsdata = wc;

	return 0;
@@ -2400,18 +2415,23 @@ int ocfs2_write_end_nolock(struct address_space *mapping, 
		goto out_write_size;

	}



	if (unlikely(copied < len)) {

	if (unlikely(copied < len) && wc->w_target_page) {

		if (!PageUptodate(wc->w_target_page))

			copied = 0;



		ocfs2_zero_new_buffers(wc->w_target_page, start+copied,

				       start+len);

	}

	if (wc->w_target_page)

		flush_dcache_page(wc->w_target_page);



	for(i = 0; i < wc->w_num_pages; i++) {

		tmppage = wc->w_pages[i];



		/* This is the direct io target page. */

		if (tmppage == NULL)

			continue;



		if (tmppage == wc->w_target_page) {

			from = wc->w_target_from;

			to = wc->w_target_to;