diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 63304154006d..c54a7c60e063 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1271,13 +1271,7 @@ xfs_prep_free_cowblocks(
 	 */
 	if (!sync && inode_is_open_for_write(VFS_I(ip)))
 		return false;
-	if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
-	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
-	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
-	    atomic_read(&VFS_I(ip)->i_dio_count))
-		return false;
-
-	return true;
+	return xfs_can_free_cowblocks(ip);
 }
 
 /*
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 3431d0d8b6f3..4058cf361d21 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1600,6 +1600,9 @@ xfs_reflink_clear_inode_flag(
 
 	ASSERT(xfs_is_reflink_inode(ip));
 
+	if (!xfs_can_free_cowblocks(ip))
+		return 0;
+
 	error = xfs_reflink_inode_has_shared_extents(*tpp, ip, &needs_flag);
 	if (error || needs_flag)
 		return error;
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 65c5dfe17ecf..67a335b247b1 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -16,6 +16,25 @@ static inline bool xfs_is_cow_inode(struct xfs_inode *ip)
 	return xfs_is_reflink_inode(ip) || xfs_is_always_cow_inode(ip);
 }
 
+/*
+ * Check whether it is safe to free COW fork blocks from an inode. It is unsafe
+ * to do so when an inode has dirty cache or I/O in-flight, even if no shared
+ * extents exist in the data fork, because outstanding I/O may target blocks
+ * that were speculatively allocated to the COW fork.
+ */
+static inline bool
+xfs_can_free_cowblocks(struct xfs_inode *ip)
+{
+	struct inode *inode = VFS_I(ip);
+
+	if ((inode->i_state & I_DIRTY_PAGES) ||
+	    mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
+	    mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
+	    atomic_read(&inode->i_dio_count))
+		return false;
+	return true;
+}
+
 extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip,
 		struct xfs_bmbt_irec *irec, bool *shared);
 int xfs_bmap_trim_cow(struct xfs_inode *ip, struct xfs_bmbt_irec *imap,