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

[Christoph Hellwig <hch@xxxxxx>]

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@xxxxxx>
---
 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