1 files changed, 9 insertions, 0 deletions

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index add06b4e9a63..364818eef40e 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -351,6 +351,15 @@ xfs_iomap_prealloc_size(
                 }
                 if (shift)
                         alloc_blocks >>= shift;
+
+                /*
+                 * If we are still trying to allocate more space than is
+                 * available, squash the prealloc hard. This can happen if we
+                 * have a large file on a small filesystem and the above
+                 * lowspace thresholds are smaller than MAXEXTLEN.
+                 */
+                while (alloc_blocks >= freesp)
+                        alloc_blocks >>= 4;
         }
 
         if (alloc_blocks < mp->m_writeio_blocks)