rbd: introduce rbd_obj_issue_copyup_ops()

In preparation for deep-flatten feature, split rbd_obj_issue_copyup()
into two functions and add a new write state to make the state machine
slightly more clear.  Make the copyup op optional and start using that
for when the overlap goes to 0.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2019-02-28 10:49:12 +01:00
parent 13488d5377
commit 3a482501cf

View file

@ -236,7 +236,8 @@ enum obj_operation_type {
enum rbd_obj_write_state {
RBD_OBJ_WRITE_FLAT = 1,
RBD_OBJ_WRITE_GUARD,
RBD_OBJ_WRITE_COPYUP,
RBD_OBJ_WRITE_READ_FROM_PARENT,
RBD_OBJ_WRITE_COPYUP_OPS,
};
struct rbd_obj_request {
@ -2458,10 +2459,13 @@ static bool is_zero_bvecs(struct bio_vec *bvecs, u32 bytes)
return true;
}
static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
#define MODS_ONLY U32_MAX
static int rbd_obj_issue_copyup_ops(struct rbd_obj_request *obj_req, u32 bytes)
{
struct rbd_img_request *img_req = obj_req->img_request;
unsigned int num_osd_ops = 1;
unsigned int num_osd_ops = (bytes != MODS_ONLY);
unsigned int which = 0;
int ret;
dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
@ -2483,31 +2487,25 @@ static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
if (!obj_req->osd_req)
return -ENOMEM;
ret = osd_req_op_cls_init(obj_req->osd_req, 0, "rbd", "copyup");
if (ret)
return ret;
if (bytes != MODS_ONLY) {
ret = osd_req_op_cls_init(obj_req->osd_req, which, "rbd",
"copyup");
if (ret)
return ret;
/*
* Only send non-zero copyup data to save some I/O and network
* bandwidth -- zero copyup data is equivalent to the object not
* existing.
*/
if (is_zero_bvecs(obj_req->copyup_bvecs, bytes)) {
dout("%s obj_req %p detected zeroes\n", __func__, obj_req);
bytes = 0;
osd_req_op_cls_request_data_bvecs(obj_req->osd_req, which++,
obj_req->copyup_bvecs,
obj_req->copyup_bvec_count,
bytes);
}
osd_req_op_cls_request_data_bvecs(obj_req->osd_req, 0,
obj_req->copyup_bvecs,
obj_req->copyup_bvec_count,
bytes);
switch (img_req->op_type) {
case OBJ_OP_WRITE:
__rbd_obj_setup_write(obj_req, 1);
__rbd_obj_setup_write(obj_req, which);
break;
case OBJ_OP_ZEROOUT:
rbd_assert(!rbd_obj_is_entire(obj_req));
__rbd_obj_setup_zeroout(obj_req, 1);
__rbd_obj_setup_zeroout(obj_req, which);
break;
default:
rbd_assert(0);
@ -2521,6 +2519,22 @@ static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
return 0;
}
static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
{
/*
* Only send non-zero copyup data to save some I/O and network
* bandwidth -- zero copyup data is equivalent to the object not
* existing.
*/
if (is_zero_bvecs(obj_req->copyup_bvecs, bytes)) {
dout("%s obj_req %p detected zeroes\n", __func__, obj_req);
bytes = 0;
}
obj_req->write_state = RBD_OBJ_WRITE_COPYUP_OPS;
return rbd_obj_issue_copyup_ops(obj_req, bytes);
}
static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
{
u32 i;
@ -2560,22 +2574,19 @@ static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
if (!obj_req->num_img_extents) {
/*
* The overlap has become 0 (most likely because the
* image has been flattened). Use rbd_obj_issue_copyup()
* to re-submit the original write request -- the copyup
* operation itself will be a no-op, since someone must
* have populated the child object while we weren't
* looking. Move to WRITE_FLAT state as we'll be done
* with the operation once the null copyup completes.
* image has been flattened). Re-submit the original write
* request -- pass MODS_ONLY since the copyup isn't needed
* anymore.
*/
obj_req->write_state = RBD_OBJ_WRITE_FLAT;
return rbd_obj_issue_copyup(obj_req, 0);
obj_req->write_state = RBD_OBJ_WRITE_COPYUP_OPS;
return rbd_obj_issue_copyup_ops(obj_req, MODS_ONLY);
}
ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
if (ret)
return ret;
obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
obj_req->write_state = RBD_OBJ_WRITE_READ_FROM_PARENT;
return rbd_obj_read_from_parent(obj_req);
}
@ -2583,7 +2594,6 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
{
int ret;
again:
switch (obj_req->write_state) {
case RBD_OBJ_WRITE_GUARD:
rbd_assert(!obj_req->xferred);
@ -2602,6 +2612,7 @@ again:
}
/* fall through */
case RBD_OBJ_WRITE_FLAT:
case RBD_OBJ_WRITE_COPYUP_OPS:
if (!obj_req->result)
/*
* There is no such thing as a successful short
@ -2609,10 +2620,9 @@ again:
*/
obj_req->xferred = obj_req->ex.oe_len;
return true;
case RBD_OBJ_WRITE_COPYUP:
obj_req->write_state = RBD_OBJ_WRITE_GUARD;
case RBD_OBJ_WRITE_READ_FROM_PARENT:
if (obj_req->result)
goto again;
return true;
rbd_assert(obj_req->xferred);
ret = rbd_obj_issue_copyup(obj_req, obj_req->xferred);