SMB3: update comment to clarify enumerating snapshots

Trivial update to comment suggested by Pavel.

Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index c36ff0d1fe2a8b7b2668466464fc9da9e45a774f..ab4737e3c31fcdabd393cb71ab75e73f9bc99859 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1821,6 +1821,14 @@ smb3_enum_snapshots(const unsigned int xid, struct cifs_tcon *tcon,
        u32 max_response_size;
        struct smb_snapshot_array snapshot_in;
 
+       /*
+        * On the first query to enumerate the list of snapshots available
+        * for this volume the buffer begins with 0 (number of snapshots
+        * which can be returned is zero since at that point we do not know
+        * how big the buffer needs to be). On the second query,
+        * it (ret_data_len) is set to number of snapshots so we can
+        * know to set the maximum response size larger (see below).
+        */
        if (get_user(ret_data_len, (unsigned int __user *)ioc_buf))
                return -EFAULT;