1 files changed, 18 insertions, 0 deletions

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index a8d0ed911196..becf4a97efc6 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -526,7 +526,25 @@ xfs_buf_item_unpin(
                 }
                 xfs_buf_relse(bp);
         } else if (freed && remove) {
+                /*
+                 * There are currently two references to the buffer - the active
+                 * LRU reference and the buf log item. What we are about to do
+                 * here - simulate a failed IO completion - requires 3
+                 * references.
+                 *
+                 * The LRU reference is removed by the xfs_buf_stale() call. The
+                 * buf item reference is removed by the xfs_buf_iodone()
+                 * callback that is run by xfs_buf_do_callbacks() during ioend
+                 * processing (via the bp->b_iodone callback), and then finally
+                 * the ioend processing will drop the IO reference if the buffer
+                 * is marked XBF_ASYNC.
+                 *
+                 * Hence we need to take an additional reference here so that IO
+                 * completion processing doesn't free the buffer prematurely.
+                 */
                 xfs_buf_lock(bp);
+                xfs_buf_hold(bp);
+                bp->b_flags |= XBF_ASYNC;
                 xfs_buf_ioerror(bp, EIO);
                 XFS_BUF_UNDONE(bp);
                 xfs_buf_stale(bp);