[PATCH 3/3] xfs: cancel COW in xfs_cancel_ioend

[Christoph Hellwig]

Otherwise we leak COW allocations done earlier in writepage.  This
can be reproduced fairly easily when we hit the non-blocking writeback
EAGAIN case.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 fs/xfs/xfs_aops.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 185415a..9c69dc3 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -588,6 +588,7 @@ xfs_cancel_ioend(
 {
 	xfs_ioend_t		*next;
 	struct buffer_head	*bh, *next_bh;
+	int			error;
 
 	do {
 		next = ioend->io_list;
@@ -605,6 +606,12 @@ xfs_cancel_ioend(
 			unlock_buffer(bh);
 		} while ((bh = next_bh) != NULL);
 
+		if (ioend->io_flags & XFS_IOEND_COW) {
+			error = xfs_reflink_end_cow_failed(
+					XFS_I(ioend->io_inode),
+					ioend->io_offset, ioend->io_size);
+			WARN_ON_ONCE(error);
+		}
 		mempool_free(ioend, xfs_ioend_pool);
 	} while ((ioend = next) != NULL);
 }
-- 
1.9.1