libceph: support for alloc hint flags

Allow indicating future I/O pattern via flags.  This is supported since
Kraken (and bluestore persists flags together with expected_object_size
and expected_write_size).
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>

drivers/block/rbd.c

@@ -2253,7 +2253,8 @@ static void __rbd_osd_setup_write_ops(struct ceph_osd_request *osd_req,
 	    !(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST)) {
 		osd_req_op_alloc_hint_init(osd_req, which++,
 					   rbd_dev->layout.object_size,
-					   rbd_dev->layout.object_size);
+					   rbd_dev->layout.object_size,
+					   0);
 	}
 
 	if (rbd_obj_is_entire(obj_req))

include/linux/ceph/osd_client.h

@@ -136,6 +136,7 @@ struct ceph_osd_req_op {
 		struct {
 			u64 expected_object_size;
 			u64 expected_write_size;
+			u32 flags;  /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
 		} alloc_hint;
 		struct {
 			u64 snapid;
@@ -472,7 +473,8 @@ extern int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int
 extern void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
 				       unsigned int which,
 				       u64 expected_object_size,
-				       u64 expected_write_size);
+				       u64 expected_write_size,
+				       u32 flags);
 
 extern struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 					       struct ceph_snap_context *snapc,

include/linux/ceph/rados.h

@@ -464,6 +464,19 @@ enum {
 
 const char *ceph_osd_watch_op_name(int o);
 
+enum {
+	CEPH_OSD_ALLOC_HINT_FLAG_SEQUENTIAL_WRITE = 1,
+	CEPH_OSD_ALLOC_HINT_FLAG_RANDOM_WRITE = 2,
+	CEPH_OSD_ALLOC_HINT_FLAG_SEQUENTIAL_READ = 4,
+	CEPH_OSD_ALLOC_HINT_FLAG_RANDOM_READ = 8,
+	CEPH_OSD_ALLOC_HINT_FLAG_APPEND_ONLY = 16,
+	CEPH_OSD_ALLOC_HINT_FLAG_IMMUTABLE = 32,
+	CEPH_OSD_ALLOC_HINT_FLAG_SHORTLIVED = 64,
+	CEPH_OSD_ALLOC_HINT_FLAG_LONGLIVED = 128,
+	CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE = 256,
+	CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE = 512,
+};
+
 enum {
 	CEPH_OSD_BACKOFF_OP_BLOCK = 1,
 	CEPH_OSD_BACKOFF_OP_ACK_BLOCK = 2,
@@ -517,6 +530,7 @@ struct ceph_osd_op {
 		struct {
 			__le64 expected_object_size;
 			__le64 expected_write_size;
+			__le32 flags;  /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
 		} __attribute__ ((packed)) alloc_hint;
 		struct {
 			__le64 snapid;

net/ceph/osd_client.c

@@ -932,10 +932,14 @@ static void osd_req_op_watch_init(struct ceph_osd_request *req, int which,
 	op->watch.gen = 0;
 }
 
+/*
+ * @flags: CEPH_OSD_OP_ALLOC_HINT_FLAG_*
+ */
 void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
 				unsigned int which,
 				u64 expected_object_size,
-				u64 expected_write_size)
+				u64 expected_write_size,
+				u32 flags)
 {
 	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
 						      CEPH_OSD_OP_SETALLOCHINT,
@@ -943,6 +947,7 @@ void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
 
 	op->alloc_hint.expected_object_size = expected_object_size;
 	op->alloc_hint.expected_write_size = expected_write_size;
+	op->alloc_hint.flags = flags;
 
 	/*
 	 * CEPH_OSD_OP_SETALLOCHINT op is advisory and therefore deemed
@@ -1018,6 +1023,7 @@ static u32 osd_req_encode_op(struct ceph_osd_op *dst,
 		    cpu_to_le64(src->alloc_hint.expected_object_size);
 		dst->alloc_hint.expected_write_size =
 		    cpu_to_le64(src->alloc_hint.expected_write_size);
+		dst->alloc_hint.flags = cpu_to_le32(src->alloc_hint.flags);
 		break;
 	case CEPH_OSD_OP_SETXATTR:
 	case CEPH_OSD_OP_CMPXATTR: