rbd: extract a method for adding object operations

rbd_img_request_fill() creates a ceph_osd_request and has logic for
adding the appropriate osd ops to it based on the request type and
image properties.

For layered images, the original rbd_obj_request is resent with a
copyup operation in front, using a new ceph_osd_request. The logic for
adding the original operations should be the same as when first
sending them, so move it to a helper function.

op_type only needs to be checked once, so create a helper for that as
well and call it outside the loop in rbd_img_request_fill().

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 6fb93cd..c07cb1d 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1672,6 +1672,17 @@ static bool img_request_layered_test(struct rbd_img_request *img_request)
        return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
 }
 
+static enum obj_operation_type
+rbd_img_request_op_type(struct rbd_img_request *img_request)
+{
+       if (img_request_write_test(img_request))
+               return OBJ_OP_WRITE;
+       else if (img_request_discard_test(img_request))
+               return OBJ_OP_DISCARD;
+       else
+               return OBJ_OP_READ;
+}
+
 static void
 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
 {
@@ -2308,6 +2319,68 @@ out:
 }
 
 /*
+ * Add individual osd ops to the given ceph_osd_request and prepare
+ * them for submission. num_ops is the current number of
+ * osd operations already to the object request.
+ */
+static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
+                               struct ceph_osd_request *osd_request,
+                               enum obj_operation_type op_type,
+                               unsigned int num_ops)
+{
+       struct rbd_img_request *img_request = obj_request->img_request;
+       struct rbd_device *rbd_dev = img_request->rbd_dev;
+       u64 object_size = rbd_obj_bytes(&rbd_dev->header);
+       u64 offset = obj_request->offset;
+       u64 length = obj_request->length;
+       u64 img_end;
+       u16 opcode;
+
+       if (op_type == OBJ_OP_DISCARD) {
+               if (!offset && (length == object_size)
+                       && (!img_request_layered_test(img_request) ||
+                               (rbd_dev->parent_overlap <=
+                                       obj_request->img_offset))) {
+                       opcode = CEPH_OSD_OP_DELETE;
+               } else if ((offset + length == object_size)) {
+                       opcode = CEPH_OSD_OP_TRUNCATE;
+               } else {
+                       down_read(&rbd_dev->header_rwsem);
+                       img_end = rbd_dev->header.image_size;
+                       up_read(&rbd_dev->header_rwsem);
+
+                       if (obj_request->img_offset + length == img_end)
+                               opcode = CEPH_OSD_OP_TRUNCATE;
+                       else
+                               opcode = CEPH_OSD_OP_ZERO;
+               }
+       } else if (op_type == OBJ_OP_WRITE) {
+               opcode = CEPH_OSD_OP_WRITE;
+               osd_req_op_alloc_hint_init(osd_request, num_ops,
+                                       object_size, object_size);
+               num_ops++;
+       } else {
+               opcode = CEPH_OSD_OP_READ;
+       }
+
+       osd_req_op_extent_init(osd_request, num_ops, opcode, offset, length,
+                               0, 0);
+       if (obj_request->type == OBJ_REQUEST_BIO)
+               osd_req_op_extent_osd_data_bio(osd_request, num_ops,
+                                       obj_request->bio_list, length);
+       else if (obj_request->type == OBJ_REQUEST_PAGES)
+               osd_req_op_extent_osd_data_pages(osd_request, num_ops,
+                                       obj_request->pages, length,
+                                       offset & ~PAGE_MASK, false, false);
+
+       /* Discards are also writes */
+       if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
+               rbd_osd_req_format_write(obj_request);
+       else
+               rbd_osd_req_format_read(obj_request);
+}
+
+/*
  * Split up an image request into one or more object requests, each
  * to a different object.  The "type" parameter indicates whether
  * "data_desc" is the pointer to the head of a list of bio
@@ -2326,11 +2399,8 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
        unsigned int bio_offset = 0;
        struct page **pages = NULL;
        enum obj_operation_type op_type;
-       u64 object_size = rbd_obj_bytes(&rbd_dev->header);
        u64 img_offset;
-       u64 img_end;
        u64 resid;
-       u16 opcode;
 
        dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
                (int)type, data_desc);
@@ -2338,6 +2408,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
        img_offset = img_request->offset;
        resid = img_request->length;
        rbd_assert(resid > 0);
+       op_type = rbd_img_request_op_type(img_request);
 
        if (type == OBJ_REQUEST_BIO) {
                bio_list = data_desc;
@@ -2352,7 +2423,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
                const char *object_name;
                u64 offset;
                u64 length;
-               unsigned int which = 0;
 
                object_name = rbd_segment_name(rbd_dev, img_offset);
                if (!object_name)
@@ -2395,66 +2465,19 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
                        pages += page_count;
                }
 
-               if (img_request_discard_test(img_request)) {
-                       op_type = OBJ_OP_DISCARD;
-                       if (!offset && (length == object_size)
-                               && (!img_request_layered_test(img_request) ||
-                                       (rbd_dev->parent_overlap <=
-                                               obj_request->img_offset))) {
-                               opcode = CEPH_OSD_OP_DELETE;
-                       } else if ((offset + length == object_size)) {
-                               opcode = CEPH_OSD_OP_TRUNCATE;
-                       } else {
-                               down_read(&rbd_dev->header_rwsem);
-                               img_end = rbd_dev->header.image_size;
-                               up_read(&rbd_dev->header_rwsem);
-
-                               if (obj_request->img_offset + length == img_end)
-                                       opcode = CEPH_OSD_OP_TRUNCATE;
-                               else
-                                       opcode = CEPH_OSD_OP_ZERO;
-                       }
-               } else if (img_request_write_test(img_request)) {
-                       op_type = OBJ_OP_WRITE;
-                       opcode = CEPH_OSD_OP_WRITE;
-               } else {
-                       op_type = OBJ_OP_READ;
-                       opcode = CEPH_OSD_OP_READ;
-               }
-
                osd_req = rbd_osd_req_create(rbd_dev, op_type,
                                        (op_type == OBJ_OP_WRITE) ? 2 : 1,
                                        obj_request);
                if (!osd_req)
                        goto out_unwind;
+
                obj_request->osd_req = osd_req;
                obj_request->callback = rbd_img_obj_callback;
-               rbd_img_request_get(img_request);
-
-               if (op_type == OBJ_OP_WRITE) {
-                       osd_req_op_alloc_hint_init(osd_req, which,
-                                            rbd_obj_bytes(&rbd_dev->header),
-                                            rbd_obj_bytes(&rbd_dev->header));
-                       which++;
-               }
-
-               osd_req_op_extent_init(osd_req, which, opcode, offset, length,
-                                      0, 0);
-               if (type == OBJ_REQUEST_BIO)
-                       osd_req_op_extent_osd_data_bio(osd_req, which,
-                                       obj_request->bio_list, length);
-               else if (type == OBJ_REQUEST_PAGES)
-                       osd_req_op_extent_osd_data_pages(osd_req, which,
-                                       obj_request->pages, length,
-                                       offset & ~PAGE_MASK, false, false);
+               obj_request->img_offset = img_offset;
 
-               /* Discards are also writes */
-               if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
-                       rbd_osd_req_format_write(obj_request);
-               else
-                       rbd_osd_req_format_read(obj_request);
+               rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
 
-               obj_request->img_offset = img_offset;
+               rbd_img_request_get(img_request);
 
                img_offset += length;
                resid -= length;