Fix livelist assertions for dedup and cloning

Two block pointers in livelist pointing to the same location may
be caused not only by dedup, but also by block cloning. We should
not assert D bit set in them.

Two block pointers in livelist pointing to the same location may
have different logical birth time in case of dedup or cloning. We
should assert identical physical birth time instead.

Assert identical physical block size between pointers in addition
to checksum, since that is what checksums are calculated on.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15732

diff --git a/module/zfs/dsl_deadlist.c b/module/zfs/dsl_deadlist.c
index 2832294b697425ad5f87a656eb5b5aada5cddc2a..e6c8d4be13b422e2dd9da1b140ec55dc668bc59c 100644 (file)
--- a/module/zfs/dsl_deadlist.c
+++ b/module/zfs/dsl_deadlist.c
@@ -1000,8 +1000,6 @@ livelist_compare(const void *larg, const void *rarg)
        /* if vdevs are equal, sort by offsets. */
        uint64_t l_dva0_offset = DVA_GET_OFFSET(&l->blk_dva[0]);
        uint64_t r_dva0_offset = DVA_GET_OFFSET(&r->blk_dva[0]);
-       if (l_dva0_offset == r_dva0_offset)
-               ASSERT3U(l->blk_birth, ==, r->blk_birth);
        return (TREE_CMP(l_dva0_offset, r_dva0_offset));
 }
 
@@ -1016,9 +1014,9 @@ struct livelist_iter_arg {
  * and used to match up ALLOC/FREE pairs. ALLOC'd blkptrs without a
  * corresponding FREE are stored in the supplied bplist.
  *
- * Note that multiple FREE and ALLOC entries for the same blkptr may
- * be encountered when dedup is involved. For this reason we keep a
- * refcount for all the FREE entries of each blkptr and ensure that
+ * Note that multiple FREE and ALLOC entries for the same blkptr may be
+ * encountered when dedup or block cloning is involved.  For this reason we
+ * keep a refcount for all the FREE entries of each blkptr and ensure that
  * each of those FREE entries has a corresponding ALLOC preceding it.
  */
 static int
@@ -1037,6 +1035,13 @@ dsl_livelist_iterate(void *arg, const blkptr_t *bp, boolean_t bp_freed,
        livelist_entry_t node;
        node.le_bp = *bp;
        livelist_entry_t *found = avl_find(avl, &node, NULL);
+       if (found) {
+               ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(&found->le_bp));
+               ASSERT3U(BP_GET_CHECKSUM(bp), ==,
+                   BP_GET_CHECKSUM(&found->le_bp));
+               ASSERT3U(BP_PHYSICAL_BIRTH(bp), ==,
+                   BP_PHYSICAL_BIRTH(&found->le_bp));
+       }
        if (bp_freed) {
                if (found == NULL) {
                        /* first free entry for this blkptr */
@@ -1046,10 +1051,10 @@ dsl_livelist_iterate(void *arg, const blkptr_t *bp, boolean_t bp_freed,
                        e->le_refcnt = 1;
                        avl_add(avl, e);
                } else {
-                       /* dedup block free */
-                       ASSERT(BP_GET_DEDUP(bp));
-                       ASSERT3U(BP_GET_CHECKSUM(bp), ==,
-                           BP_GET_CHECKSUM(&found->le_bp));
+                       /*
+                        * Deduped or cloned block free.  We could assert D bit
+                        * for dedup, but there is no such one for cloning.
+                        */
                        ASSERT3U(found->le_refcnt + 1, >, found->le_refcnt);
                        found->le_refcnt++;
                }
@@ -1065,14 +1070,6 @@ dsl_livelist_iterate(void *arg, const blkptr_t *bp, boolean_t bp_freed,
                                /* all tracked free pairs have been matched */
                                avl_remove(avl, found);
                                kmem_free(found, sizeof (livelist_entry_t));
-                       } else {
-                               /*
-                                * This is definitely a deduped blkptr so
-                                * let's validate it.
-                                */
-                               ASSERT(BP_GET_DEDUP(bp));
-                               ASSERT3U(BP_GET_CHECKSUM(bp), ==,
-                                   BP_GET_CHECKSUM(&found->le_bp));
                        }
                }
        }