LU-10286 mdt: deny 2.10 clients to open mirrored files

[fs/lustre-release.git] / lustre / mdt / mdt_open.c

diff --git a/lustre/mdt/mdt_open.c b/lustre/mdt/mdt_open.c
index f477d99..32b9aea 100644 (file)
--- a/lustre/mdt/mdt_open.c
+++ b/lustre/mdt/mdt_open.c
@@ -522,6 +522,21 @@ static int mdt_finish_open(struct mdt_thread_info *info,
         islnk = S_ISLNK(la->la_mode);
         mdt_pack_attr2body(info, repbody, la, mdt_object_fid(o));
 
+       /* compatibility check for 2.10 clients when it tries to open mirrored
+        * files. 2.10 clients don't verify overlapping components so they
+        * would read and write mirrored files just as if they were normal
+        * PFL files, which will cause the problem that sycned mirrors actually
+        * contain different data.
+        * Older clients are not a concern here because they don't even
+        * understand PFL layout. */
+       if (isreg && !exp_connect_flr(exp) && ma->ma_valid & MA_LOV &&
+           mdt_lmm_is_flr(ma->ma_lmm)) {
+               /* LU-10286: for simplicity clients who don't understand
+                * mirrored layout(with connect flag OBD_CONNECT2_FLR) won't
+                * be able to open mirrored files */
+               RETURN(-EOPNOTSUPP);
+       }
+
        /* LU-2275, simulate broken behaviour (esp. prevalent in
         * pre-2.4 servers where a very strange reply is sent on error
         * that looks like it was actually almost successful and a