[PATCH] Btrfs: fix compressed write corruption on enospc

[Liu Bo <bo.li.liu@oracle.com>]

When failing to allocate space for the whole compressed extent, we'll
fallback to uncompressed IO, but we've forgotten to redirty the pages
which belong to this compressed extent, and these 'clean' pages will
simply skip 'submit' part and go to endio directly, at last we got data
corruption as we write nothing.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/inode.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3668048..8ea7610 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -709,6 +709,18 @@ retry:
 				unlock_extent(io_tree, async_extent->start,
 					      async_extent->start +
 					      async_extent->ram_size - 1);
+
+				/*
+				 * we need to redirty the pages if we decide to
+				 * fallback to uncompressed IO, otherwise we
+				 * will not submit these pages down to lower
+				 * layers.
+				 */
+				extent_range_redirty_for_io(inode,
+						async_extent->start,
+						async_extent->start +
+						async_extent->ram_size - 1);
+
 				goto retry;
 			}
 			goto out_free;
-- 
1.8.1.4