From 49d4a334727057af57048ded99697d17b016d91b Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Mon, 6 Mar 2017 18:20:56 -0800 Subject: [PATCH] Btrfs: fix regression in lock_delalloc_pages The bug is a regression after commit (da2c7009f6ca "btrfs: teach __process_pages_contig about PAGE_LOCK operation") and commit (76c0021db8fd "Btrfs: use helper to simplify lock/unlock pages"). So if the dirty pages which are under writeback got truncated partially before we lock the dirty pages, we couldn't find all pages mapping to the delalloc range, and the bug didn't return an error so it kept going on and found that the delalloc range got truncated and got to unlock the dirty pages, and then the ASSERT could caught the error, and showed ----------------------------------------------------------------------------- assertion failed: page_ops & PAGE_LOCK, file: fs/btrfs/extent_io.c, line: 1716 ----------------------------------------------------------------------------- This fixes the bug by returning the proper -EAGAIN. Cc: David Sterba Reported-by: Dave Jones Signed-off-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 28e81922a21c..8df797432740 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1714,7 +1714,8 @@ static int __process_pages_contig(struct address_space *mapping, * can we find nothing at @index. */ ASSERT(page_ops & PAGE_LOCK); - return ret; + err = -EAGAIN; + goto out; } for (i = 0; i < ret; i++) { -- 2.20.1