rbd: switch to common striping framework

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 168 insertions, 23 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index fc94e2c45e28..24f169f33219 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1326,7 +1326,6 @@ static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
         obj_request->img_request = img_request;
         img_request->obj_request_count++;
         img_request->pending_count++;
-        list_add_tail(&obj_request->ex.oe_item, &img_request->object_extents);
         dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
 }
 
@@ -2055,6 +2054,158 @@ out_unwind:
         return -ENOMEM;
 }
 
+union rbd_img_fill_iter {
+        struct ceph_bio_iter    bio_iter;
+        struct ceph_bvec_iter   bvec_iter;
+};
+
+struct rbd_img_fill_ctx {
+        enum obj_request_type   pos_type;
+        union rbd_img_fill_iter *pos;
+        union rbd_img_fill_iter iter;
+        ceph_object_extent_fn_t set_pos_fn;
+};
+
+static struct ceph_object_extent *alloc_object_extent(void *arg)
+{
+        struct rbd_img_request *img_req = arg;
+        struct rbd_obj_request *obj_req;
+
+        obj_req = rbd_obj_request_create();
+        if (!obj_req)
+                return NULL;
+
+        rbd_img_obj_request_add(img_req, obj_req);
+        return &obj_req->ex;
+}
+
+/*
+ * Map a list of image extents to a list of object extents, create the
+ * corresponding object requests (normally each to a different object,
+ * but not always) and add them to @img_req.  For each object request,
+ * set up its data descriptor to point to the corresponding chunk of
+ * @fctx->pos data buffer.
+ *
+ * @fctx->pos data buffer is assumed to be large enough.
+ */
+static int rbd_img_fill_request(struct rbd_img_request *img_req,
+                                struct ceph_file_extent *img_extents,
+                                u32 num_img_extents,
+                                struct rbd_img_fill_ctx *fctx)
+{
+        u32 i;
+        int ret;
+
+        img_req->data_type = fctx->pos_type;
+
+        /*
+         * Create object requests and set each object request's starting
+         * position in the provided bio (list) or bio_vec array.
+         */
+        fctx->iter = *fctx->pos;
+        for (i = 0; i < num_img_extents; i++) {
+                ret = ceph_file_to_extents(&img_req->rbd_dev->layout,
+                                           img_extents[i].fe_off,
+                                           img_extents[i].fe_len,
+                                           &img_req->object_extents,
+                                           alloc_object_extent, img_req,
+                                           fctx->set_pos_fn, &fctx->iter);
+                if (ret)
+                        return ret;
+        }
+
+        return __rbd_img_fill_request(img_req);
+}
+
+static int rbd_img_fill_nodata(struct rbd_img_request *img_req,
+                               u64 off, u64 len)
+{
+        struct ceph_file_extent ex = { off, len };
+        union rbd_img_fill_iter dummy;
+        struct rbd_img_fill_ctx fctx = {
+                .pos_type = OBJ_REQUEST_NODATA,
+                .pos = &dummy,
+        };
+
+        return rbd_img_fill_request(img_req, &ex, 1, &fctx);
+}
+
+static void set_bio_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+        struct rbd_obj_request *obj_req =
+            container_of(ex, struct rbd_obj_request, ex);
+        struct ceph_bio_iter *it = arg;
+
+        dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
+        obj_req->bio_pos = *it;
+        ceph_bio_iter_advance(it, bytes);
+}
+
+static int __rbd_img_fill_from_bio(struct rbd_img_request *img_req,
+                                   struct ceph_file_extent *img_extents,
+                                   u32 num_img_extents,
+                                   struct ceph_bio_iter *bio_pos)
+{
+        struct rbd_img_fill_ctx fctx = {
+                .pos_type = OBJ_REQUEST_BIO,
+                .pos = (union rbd_img_fill_iter *)bio_pos,
+                .set_pos_fn = set_bio_pos,
+        };
+
+        return rbd_img_fill_request(img_req, img_extents, num_img_extents,
+                                    &fctx);
+}
+
+static int rbd_img_fill_from_bio(struct rbd_img_request *img_req,
+                                 u64 off, u64 len, struct bio *bio)
+{
+        struct ceph_file_extent ex = { off, len };
+        struct ceph_bio_iter it = { .bio = bio, .iter = bio->bi_iter };
+
+        return __rbd_img_fill_from_bio(img_req, &ex, 1, &it);
+}
+
+static void set_bvec_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+        struct rbd_obj_request *obj_req =
+            container_of(ex, struct rbd_obj_request, ex);
+        struct ceph_bvec_iter *it = arg;
+
+        obj_req->bvec_pos = *it;
+        ceph_bvec_iter_shorten(&obj_req->bvec_pos, bytes);
+        ceph_bvec_iter_advance(it, bytes);
+}
+
+static int __rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
+                                     struct ceph_file_extent *img_extents,
+                                     u32 num_img_extents,
+                                     struct ceph_bvec_iter *bvec_pos)
+{
+        struct rbd_img_fill_ctx fctx = {
+                .pos_type = OBJ_REQUEST_BVECS,
+                .pos = (union rbd_img_fill_iter *)bvec_pos,
+                .set_pos_fn = set_bvec_pos,
+        };
+
+        return rbd_img_fill_request(img_req, img_extents, num_img_extents,
+                                    &fctx);
+}
+
+static int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
+                                   struct ceph_file_extent *img_extents,
+                                   u32 num_img_extents,
+                                   struct bio_vec *bvecs)
+{
+        struct ceph_bvec_iter it = {
+                .bvecs = bvecs,
+                .iter = { .bi_size = ceph_file_extents_bytes(img_extents,
+                                                             num_img_extents) },
+        };
+
+        return __rbd_img_fill_from_bvecs(img_req, img_extents, num_img_extents,
+                                         &it);
+}
+
 static void rbd_img_request_submit(struct rbd_img_request *img_request)
 {
         struct rbd_obj_request *obj_request;
@@ -2083,26 +2234,25 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
         if (!rbd_img_is_write(img_req)) {
                 switch (img_req->data_type) {
                 case OBJ_REQUEST_BIO:
-                        ret = rbd_img_request_fill(child_img_req,
-                                                   OBJ_REQUEST_BIO,
-                                                   &obj_req->bio_pos);
+                        ret = __rbd_img_fill_from_bio(child_img_req,
+                                                      obj_req->img_extents,
+                                                      obj_req->num_img_extents,
+                                                      &obj_req->bio_pos);
                         break;
                 case OBJ_REQUEST_BVECS:
-                        ret = rbd_img_request_fill(child_img_req,
-                                                   OBJ_REQUEST_BVECS,
-                                                   &obj_req->bvec_pos);
+                        ret = __rbd_img_fill_from_bvecs(child_img_req,
+                                                      obj_req->img_extents,
+                                                      obj_req->num_img_extents,
+                                                      &obj_req->bvec_pos);
                         break;
                 default:
                         rbd_assert(0);
                 }
         } else {
-                struct ceph_bvec_iter it = {
-                        .bvecs = obj_req->copyup_bvecs,
-                        .iter = { .bi_size = obj_req->img_extents[0].fe_len },
-                };
-
-                ret = rbd_img_request_fill(child_img_req, OBJ_REQUEST_BVECS,
-                                           &it);
+                ret = rbd_img_fill_from_bvecs(child_img_req,
+                                              obj_req->img_extents,
+                                              obj_req->num_img_extents,
+                                              obj_req->copyup_bvecs);
         }
         if (ret) {
                 rbd_img_request_put(child_img_req);
@@ -3520,15 +3670,10 @@ static void rbd_queue_workfn(struct work_struct *work)
         snapc = NULL; /* img_request consumes a ref */
 
         if (op_type == OBJ_OP_DISCARD)
-                result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
-                                              NULL);
-        else {
-                struct ceph_bio_iter bio_it = { .bio = rq->bio,
-                                                .iter = rq->bio->bi_iter };
-
-                result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
-                                              &bio_it);
-        }
+                result = rbd_img_fill_nodata(img_request, offset, length);
+        else
+                result = rbd_img_fill_from_bio(img_request, offset, length,
+                                               rq->bio);
         if (result)
                 goto err_img_request;