LU-10910 mdd: deny layout swap for DoM file

[fs/lustre-release.git] / lustre / mdd / mdd_object.c

diff --git a/lustre/mdd/mdd_object.c b/lustre/mdd/mdd_object.c
index 8f9085c..7f73595 100644 (file)
--- a/lustre/mdd/mdd_object.c
+++ b/lustre/mdd/mdd_object.c
@@ -2151,6 +2151,30 @@ static inline int mdd_set_lmm_gen(struct lov_mds_md *lmm, __u32 *gen)
        return mdd_lmm_gen(lmm, gen, false);
 }
 
+static inline __u64 mdd_lmm_dom_size(void *buf)
+{
+       struct lov_mds_md *lmm = buf;
+       struct lov_comp_md_v1 *comp_v1;
+       struct lov_mds_md *v1;
+       __u32 off;
+
+       if (lmm == NULL)
+               return 0;
+
+       if (le32_to_cpu(lmm->lmm_magic) != LOV_MAGIC_COMP_V1)
+               return 0;
+
+       comp_v1 = (struct lov_comp_md_v1 *)lmm;
+       off = le32_to_cpu(comp_v1->lcm_entries[0].lcme_offset);
+       v1 = (struct lov_mds_md *)((char *)comp_v1 + off);
+
+       /* DoM entry is the first entry always */
+       if (lov_pattern(le32_to_cpu(v1->lmm_pattern)) == LOV_PATTERN_MDT)
+               return le64_to_cpu(comp_v1->lcm_entries[0].lcme_extent.e_end);
+
+       return 0;
+}
+
 /**
  * swap layouts between 2 lustre objects
  */
@@ -2217,6 +2241,18 @@ static int mdd_swap_layouts(const struct lu_env *env, struct md_object *obj1,
        if (rc < 0 && rc != -ENODATA)
                GOTO(stop, rc);
 
+       /* check if file is DoM, it can be migrated only to another DoM layout
+        * with the same DoM component size
+        */
+       if (mdd_lmm_dom_size(fst_buf->lb_buf) !=
+           mdd_lmm_dom_size(snd_buf->lb_buf)) {
+               rc = -EOPNOTSUPP;
+               CDEBUG(D_LAYOUT, "cannot swap layout for "DFID": new layout "
+                      "must have the same DoM component: rc = %d\n",
+                      PFID(mdo2fid(fst_o)), rc);
+               GOTO(stop, rc);
+       }
+
        /* swapping 2 non existant layouts is a success */
        if (fst_buf->lb_buf == NULL && snd_buf->lb_buf == NULL)
                GOTO(stop, rc = 0);