Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8227b297 authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: fix hang problem of log writer which occurs after write failures 



Leandro Lucarella gave me a report that nilfs gets stuck after its
write function fails.

The problem turned out to be caused by bugs which leave writeback flag
on pages.  This fixes the problem by ensuring to clear the writeback
flag in error path.

Reported-by: default avatarLeandro Lucarella <llucax@gmail.com>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: stable@kernel.org
parent 0cfae3d8

fs/nilfs2/segment.c

+6 −20
Original line number Diff line number Diff line
@@ -1836,19 +1836,6 @@ static int nilfs_segctor_write(struct nilfs_sc_info *sci, 
	return 0;

}



static int nilfs_page_has_uncleared_buffer(struct page *page)

{

	struct buffer_head *head, *bh;



	head = bh = page_buffers(page);

	do {

		if (buffer_dirty(bh) && !list_empty(&bh->b_assoc_buffers))

			return 1;

		bh = bh->b_this_page;

	} while (bh != head);

	return 0;

}



static void __nilfs_end_page_io(struct page *page, int err)

{

	if (!err) {
@@ -1872,12 +1859,11 @@ static void nilfs_end_page_io(struct page *page, int err) 
	if (!page)

		return;



	if (buffer_nilfs_node(page_buffers(page)) &&

	    nilfs_page_has_uncleared_buffer(page))

		/* For b-tree node pages, this function may be called twice

		   or more because they might be split in a segment.

		   This check assures that cleanup has been done for all

		   buffers in a split btnode page. */

	if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page))

		/*

		 * For b-tree node pages, this function may be called twice

		 * or more because they might be split in a segment.

		 */

		return;



	__nilfs_end_page_io(page, err);
@@ -1940,7 +1926,7 @@ static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci, 
			}

			if (bh->b_page != fs_page) {

				nilfs_end_page_io(fs_page, err);

				if (unlikely(fs_page == failed_page))

				if (fs_page && fs_page == failed_page)

					goto done;

				fs_page = bh->b_page;

			}