[PATCH 4.13 099/110] btrfs: clear ordered flag on cleaning up ordered extents

[Greg Kroah-Hartman]

4.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Naohiro Aota <naohiro.aota@xxxxxxx>

commit 63d71450c8d817649a79e37d685523f988b9cc98 upstream.

Commit 524272607e88 ("btrfs: Handle delalloc error correctly to avoid
ordered extent hang") introduced btrfs_cleanup_ordered_extents() to cleanup
submitted ordered extents. However, it does not clear the ordered bit
(Private2) of corresponding pages. Thus, the following BUG occurs from
free_pages_check_bad() (on btrfs/125 with nospace_cache).

BUG: Bad page state in process btrfs  pfn:3fa787
page:ffffdf2acfe9e1c0 count:0 mapcount:0 mapping:          (null) index:0xd
flags: 0x8000000000002008(uptodate|private_2)
raw: 8000000000002008 0000000000000000 000000000000000d 00000000ffffffff
raw: ffffdf2acf5c1b20 ffffb443802238b0 0000000000000000 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
bad because of flags: 0x2000(private_2)

This patch clears the flag same as other places calling
btrfs_dec_test_ordered_pending() for every page in the specified range.

Fixes: 524272607e88 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang")
Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
Reviewed-by: Qu Wenruo <quwenruo.btrfs@xxxxxxx>
Reviewed-by: Josef Bacik <jbacik@xxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/btrfs/inode.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -135,6 +135,18 @@ static inline void btrfs_cleanup_ordered
 						 const u64 offset,
 						 const u64 bytes)
 {
+	unsigned long index = offset >> PAGE_SHIFT;
+	unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
+	struct page *page;
+
+	while (index <= end_index) {
+		page = find_get_page(inode->i_mapping, index);
+		index++;
+		if (!page)
+			continue;
+		ClearPagePrivate2(page);
+		put_page(page);
+	}
 	return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
 					    bytes - PAGE_SIZE, false);
 }