Ceph

Empty object <== object with empty name

i think that if was there for the pg ops (PGLS) where there is no object... the list_objects code is filling in the pgid explicitly, i think.

Ah, you're right. I missed that function when looking to see who filled in the op->pgid.

In that case we should maybe be checking if the op->pgid is default-initialized? I don't know if our hash algorithms can output zero for the placement seed or not.

Otherwise we'll need to add a flag "explictly calculated target" that the listing code can set, or guard for empty object names farther up in the code hierarchy. (That might be better, actually, although I hate to clutter things up that way.)

From what I see, the pg ops call pool_op_submit() and not op_submit() so Greg's fix might be ok?

Ah, nope. list_objects is broken.

i prefer an explicit separate field for oid-vs-pg mode so that we can distinguish between pg 0.0 (really) and no pg/not initialized.

Would something like this work (not tested)?

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index 24b95d2..acd4ef7 100644
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -974,7 +974,7 @@ int Objecter::recalc_op_target(Op *op)
 {
   vector<int> acting;
   pg_t pgid = op->pgid;
-  if (op->oid.name.length()) {
+  if (!op->precalc_pgid) {
     int ret = osdmap->object_locator_to_pg(op->oid, op->oloc, pgid);
     if (ret == -ENOENT)
       return RECALC_OP_TARGET_POOL_DNE;
@@ -1349,6 +1349,7 @@ void Objecter::list_objects(ListContext *list_context, Context *onfinish) {
   o->reply_epoch = &onack->epoch;

   o->pgid = pg_t(list_context->current_pg, list_context->pool_id, -1);
+  o->precalc_pgid = true;

   op_submit(o);
 }
diff --git a/src/osdc/Objecter.h b/src/osdc/Objecter.h
index e733d33..d90e314 100644
--- a/src/osdc/Objecter.h
+++ b/src/osdc/Objecter.h
@@ -598,6 +598,8 @@ public:

     utime_t stamp;

+    bool precalc_pgid;
+
     Op(const object_t& o, const object_locator_t& ol, vector<OSDOp>& op,
        int f, Context *ac, Context *co, eversion_t *ov) :
       session(NULL), session_item(this), incarnation(0),
@@ -607,7 +609,7 @@ public:
       outbl(NULL),
       flags(f), priority(0), onack(ac), oncommit(co),
       tid(0), attempts(0),

-      paused(false), objver(ov), reply_epoch(NULL) {
+      paused(false), objver(ov), reply_epoch(NULL), precalc_pgid(false) {
       ops.swap(op);

       /* initialize out_* to match op vector */

that looks right to me.

and yeah, i don't think object operations should be possible on an empty object name...