Commit 81465028 authored Sep 23, 2014 by Liu Bo Committed by Chris Mason Oct 03, 2014

Btrfs: fix crash of btrfs_release_extent_buffer_page

This is actually inspired by Filipe's patch. When write_one_eb() fails on
submit_extent_page(), it'll give up writing this eb and mark it with
EXTENT_BUFFER_IOERR. So if it's not the last page that encounter the failure,
there are some left pages which remain DIRTY, and if a later COW on this eb
happens, ie. eb is COWed and freed, it'd run into BUG_ON in
btrfs_release_extent_buffer_page() for the DIRTY page, ie. BUG_ON(PageDirty(page));

This adds the missing clear_page_dirty_for_io() for the rest pages of eb.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

parent 55e3bd2e

fs/btrfs/extent_io.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -3677,6 +3677,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
		if (unlikely(ret)) {
		for (; i < num_pages; i++) {
		struct page *p = extent_buffer_page(eb, i);
		clear_page_dirty_for_io(p);
		unlock_page(p);
		}
		}

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