ceph osd: add support for new op writesame

This adds a new ceph request writesame that writes a buffer of length writesame.data_length bytes at writesame.offset over writesame.length bytes. This command maps to SCSI's WRITE SAME request, so users like LIO+rbd can pass this to the OSD. Right now, it only saves having to transfer writesame.length bytes over the network, but future versions will be to fully offload it by passing it directly to the FS/devices if they support it. v2: - Fix tab/spaces to matching coding style. - Allow zero write length. Check for invalid data lengths. Signed-off-by: Mike Christie <[email protected]> Reviewed-by: David Disseldorp <[email protected]>
allenk · Apr 25, 2016 · e334ba9 · e334ba9
1 parent ff18083
commit e334ba9
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diff --git a/src/include/rados.h b/src/include/rados.h
@@ -256,6 +256,9 @@ extern const char *ceph_osd_state_name(int s);
 	f(CACHE_PIN,	__CEPH_OSD_OP(WR, DATA, 36),	"cache-pin")        \
 	f(CACHE_UNPIN,	__CEPH_OSD_OP(WR, DATA, 37),	"cache-unpin")      \
 									    \
+	/* ESX/SCSI */							    \
+	f(WRITESAME,	__CEPH_OSD_OP(WR, DATA, 38),	"write-same")	    \
+									    \
 	/** multi **/							    \
 	f(CLONERANGE,	__CEPH_OSD_OP(WR, MULTI, 1),	"clonerange")	    \
 	f(ASSERT_SRC_VERSION, __CEPH_OSD_OP(RD, MULTI, 2), "assert-src-version") \
@@ -533,6 +536,11 @@ struct ceph_osd_op {
 			__le64 expected_object_size;
 			__le64 expected_write_size;
 		} __attribute__ ((packed)) alloc_hint;
+		struct {
+			__le64 offset;
+			__le64 length;
+			__le64 data_length;
+		} __attribute__ ((packed)) writesame;
 	};
 	__le32 payload_len;
 } __attribute__ ((packed));

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
@@ -3701,6 +3701,40 @@ int ReplicatedPG::do_xattr_cmp_str(int op, string& v1s, bufferlist& xattr)
   }
 }
 
+int ReplicatedPG::do_writesame(OpContext *ctx, OSDOp& osd_op)
+{
+  ceph_osd_op& op = osd_op.op;
+  vector<OSDOp> write_ops(1);
+  OSDOp& write_op = write_ops[0];
+  uint64_t write_length = op.writesame.length;
+  int result = 0;
+
+  if (!write_length)
+    return 0;
+
+  if (!op.writesame.data_length || write_length % op.writesame.data_length)
+    return -EINVAL;
+
+  if (op.writesame.data_length != osd_op.indata.length()) {
+    derr << "invalid length ws data length " << op.writesame.data_length << " actual len " << osd_op.indata.length() << dendl;
+    return -EINVAL;
+  }
+
+  while (write_length) {
+    write_op.indata.append(osd_op.indata.c_str(), op.writesame.data_length);
+    write_length -= op.writesame.data_length;
+  }
+
+  write_op.op.op = CEPH_OSD_OP_WRITE;
+  write_op.op.extent.offset = op.writesame.offset;
+  write_op.op.extent.length = op.writesame.length;
+  result = do_osd_ops(ctx, write_ops);
+  if (result < 0)
+    derr << "do_writesame do_osd_ops failed " << result << dendl;
+
+  return result;
+}
+
 // ========================================================================
 // low level osd ops
 
@@ -5085,6 +5119,12 @@ int ReplicatedPG::do_osd_ops(OpContext *ctx, vector<OSDOp>& ops)
       }
       break;
 
+    case CEPH_OSD_OP_WRITESAME:
+      ++ctx->num_write;
+      tracepoint(osd, do_osd_op_pre_writesame, soid.oid.name.c_str(), soid.snap.val, oi.size, op.writesame.offset, op.writesame.length, op.writesame.data_length);
+      result = do_writesame(ctx, osd_op);
+      break;
+
     case CEPH_OSD_OP_ROLLBACK :
       ++ctx->num_write;
       tracepoint(osd, do_osd_op_pre_rollback, soid.oid.name.c_str(), soid.snap.val);

diff --git a/src/osd/ReplicatedPG.h b/src/osd/ReplicatedPG.h
@@ -1412,6 +1412,8 @@ class ReplicatedPG : public PG, public PGBackend::Listener {
   int do_xattr_cmp_u64(int op, __u64 v1, bufferlist& xattr);
   int do_xattr_cmp_str(int op, string& v1s, bufferlist& xattr);
 
+  int do_writesame(OpContext *ctx, OSDOp& osd_op);
+
   bool pgls_filter(PGLSFilter *filter, hobject_t& sobj, bufferlist& outdata);
   int get_pgls_filter(bufferlist::iterator& iter, PGLSFilter **pfilter);
 

diff --git a/src/tracing/osd.tp b/src/tracing/osd.tp
@@ -381,6 +381,24 @@ TRACEPOINT_EVENT(osd, do_osd_op_pre_writefull,
     )
 )
 
+TRACEPOINT_EVENT(osd, do_osd_op_pre_writesame,
+    TP_ARGS(
+        const char*, oid,
+        uint64_t, snap,
+        uint64_t, osize,
+        uint64_t, offset,
+        uint64_t, length,
+        uint64_t, data_length),
+    TP_FIELDS(
+        ctf_string(oid, oid)
+        ctf_integer(uint64_t, snap, snap)
+        ctf_integer(uint64_t, osize, osize)
+        ctf_integer(uint64_t, offset, offset)
+        ctf_integer(uint64_t, length, length)
+        ctf_integer(uint64_t, data_length, data_length)
+    )
+)
+
 TRACEPOINT_EVENT(osd, do_osd_op_pre_rollback,
     TP_ARGS(
         const char*, oid,