diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 56b0f109e41b..1dbcfd163ff0 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -3038,13 +3038,20 @@ int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start,
 
 void cifs_setsize(struct inode *inode, loff_t offset)
 {
+	loff_t old_size;
+	u64 blocks = CIFS_INO_BLOCKS(offset);
+
 	spin_lock(&inode->i_lock);
+	old_size = i_size_read(inode);
 	i_size_write(inode, offset);
+
 	/*
-	 * Until we can query the server for actual allocation size,
-	 * this is best estimate we have for blocks allocated for a file.
+	 * Extending EOF does not allocate the intervening range. Only clamp
+	 * i_blocks on shrink; allocation growth comes from writes or from the
+	 * server-reported AllocationSize.
 	 */
-	inode->i_blocks = CIFS_INO_BLOCKS(offset);
+	if (offset < old_size && (u64)inode->i_blocks > blocks)
+		inode->i_blocks = blocks;
 	spin_unlock(&inode->i_lock);
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 	truncate_pagecache(inode, offset);