rbd: stop copying num_osd_ops in rbd_obj_issue_copyup()

In preparation for deep-flatten feature, stop copying num_osd_ops from
the original request in rbd_obj_issue_copyup().  Split the calculation
into count_{write,zeroout}_ops() respectively and determine whether the
assert_exists guard is needed with the new rbd_obj_copyup_enabled().

As a nice side effect, we no longer guard in the writefull case as the
copyup'ed object is always fully overwritten.

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

1 files changed, 59 insertions, 31 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 66915528298e..f9cad40d95af 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1424,6 +1424,18 @@ static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
                                         rbd_dev->layout.object_size;
 }
 
+/*
+ * Must be called after rbd_obj_calc_img_extents().
+ */
+static bool rbd_obj_copyup_enabled(struct rbd_obj_request *obj_req)
+{
+        if (!obj_req->num_img_extents ||
+            rbd_obj_is_entire(obj_req))
+                return false;
+
+        return true;
+}
+
 static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)
 {
         return ceph_file_extents_bytes(obj_req->img_extents,
@@ -1810,6 +1822,11 @@ static int __rbd_obj_setup_stat(struct rbd_obj_request *obj_req,
         return 0;
 }
 
+static int count_write_ops(struct rbd_obj_request *obj_req)
+{
+        return 2; /* setallochint + write/writefull */
+}
+
 static void __rbd_obj_setup_write(struct rbd_obj_request *obj_req,
                                   unsigned int which)
 {
@@ -1836,6 +1853,7 @@ static void __rbd_obj_setup_write(struct rbd_obj_request *obj_req,
 static int rbd_obj_setup_write(struct rbd_obj_request *obj_req)
 {
         unsigned int num_osd_ops, which = 0;
+        bool need_guard;
         int ret;
 
         /* reverse map the entire object onto the parent */
@@ -1843,22 +1861,21 @@ static int rbd_obj_setup_write(struct rbd_obj_request *obj_req)
         if (ret)
                 return ret;
 
-        if (obj_req->num_img_extents) {
-                obj_req->write_state = RBD_OBJ_WRITE_GUARD;
-                num_osd_ops = 3; /* stat + setallochint + write/writefull */
-        } else {
-                obj_req->write_state = RBD_OBJ_WRITE_FLAT;
-                num_osd_ops = 2; /* setallochint + write/writefull */
-        }
+        need_guard = rbd_obj_copyup_enabled(obj_req);
+        num_osd_ops = need_guard + count_write_ops(obj_req);
 
         obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
         if (!obj_req->osd_req)
                 return -ENOMEM;
 
-        if (obj_req->num_img_extents) {
+        if (need_guard) {
                 ret = __rbd_obj_setup_stat(obj_req, which++);
                 if (ret)
                         return ret;
+
+                obj_req->write_state = RBD_OBJ_WRITE_GUARD;
+        } else {
+                obj_req->write_state = RBD_OBJ_WRITE_FLAT;
         }
 
         __rbd_obj_setup_write(obj_req, which);
@@ -1919,6 +1936,18 @@ static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req)
         return 0;
 }
 
+static int count_zeroout_ops(struct rbd_obj_request *obj_req)
+{
+        int num_osd_ops;
+
+        if (rbd_obj_is_entire(obj_req) && obj_req->num_img_extents)
+                num_osd_ops = 2; /* create + truncate */
+        else
+                num_osd_ops = 1; /* delete/truncate/zero */
+
+        return num_osd_ops;
+}
+
 static void __rbd_obj_setup_zeroout(struct rbd_obj_request *obj_req,
                                     unsigned int which)
 {
@@ -1950,6 +1979,7 @@ static void __rbd_obj_setup_zeroout(struct rbd_obj_request *obj_req,
 static int rbd_obj_setup_zeroout(struct rbd_obj_request *obj_req)
 {
         unsigned int num_osd_ops, which = 0;
+        bool need_guard;
         int ret;
 
         /* reverse map the entire object onto the parent */
@@ -1957,30 +1987,21 @@ static int rbd_obj_setup_zeroout(struct rbd_obj_request *obj_req)
         if (ret)
                 return ret;
 
-        if (rbd_obj_is_entire(obj_req)) {
-                obj_req->write_state = RBD_OBJ_WRITE_FLAT;
-                if (obj_req->num_img_extents)
-                        num_osd_ops = 2; /* create + truncate */
-                else
-                        num_osd_ops = 1; /* delete */
-        } else {
-                if (obj_req->num_img_extents) {
-                        obj_req->write_state = RBD_OBJ_WRITE_GUARD;
-                        num_osd_ops = 2; /* stat + truncate/zero */
-                } else {
-                        obj_req->write_state = RBD_OBJ_WRITE_FLAT;
-                        num_osd_ops = 1; /* truncate/zero */
-                }
-        }
+        need_guard = rbd_obj_copyup_enabled(obj_req);
+        num_osd_ops = need_guard + count_zeroout_ops(obj_req);
 
         obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
         if (!obj_req->osd_req)
                 return -ENOMEM;
 
-        if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) {
+        if (need_guard) {
                 ret = __rbd_obj_setup_stat(obj_req, which++);
                 if (ret)
                         return ret;
+
+                obj_req->write_state = RBD_OBJ_WRITE_GUARD;
+        } else {
+                obj_req->write_state = RBD_OBJ_WRITE_FLAT;
         }
 
         __rbd_obj_setup_zeroout(obj_req, which);
@@ -2439,18 +2460,25 @@ static bool is_zero_bvecs(struct bio_vec *bvecs, u32 bytes)
 
 static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
 {
-        unsigned int num_osd_ops = obj_req->osd_req->r_num_ops;
+        struct rbd_img_request *img_req = obj_req->img_request;
+        unsigned int num_osd_ops = 1;
         int ret;
 
         dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
         rbd_assert(obj_req->osd_req->r_ops[0].op == CEPH_OSD_OP_STAT);
         rbd_osd_req_destroy(obj_req->osd_req);
 
-        /*
-         * Create a copyup request with the same number of OSD ops as
-         * the original request.  The original request was stat + op(s),
-         * the new copyup request will be copyup + the same op(s).
-         */
+        switch (img_req->op_type) {
+        case OBJ_OP_WRITE:
+                num_osd_ops += count_write_ops(obj_req);
+                break;
+        case OBJ_OP_ZEROOUT:
+                num_osd_ops += count_zeroout_ops(obj_req);
+                break;
+        default:
+                rbd_assert(0);
+        }
+
         obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
         if (!obj_req->osd_req)
                 return -ENOMEM;
@@ -2473,7 +2501,7 @@ static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
                                           obj_req->copyup_bvec_count,
                                           bytes);
 
-        switch (obj_req->img_request->op_type) {
+        switch (img_req->op_type) {
         case OBJ_OP_WRITE:
                 __rbd_obj_setup_write(obj_req, 1);
                 break;