From 59e542c869895fb37005b60058a342187bb63c61 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Wed, 12 Feb 2020 15:23:58 +0100 Subject: rbd: embed image request in blk-mq pdu Avoid making allocations for !IMG_REQ_CHILD image requests. Only IMG_REQ_CHILD image requests need to be freed now. Move the initial request checks to rbd_queue_rq(). Unfortunately we can't fill the image request and kick the state machine directly from rbd_queue_rq() because ->queue_rq() isn't allowed to block. Signed-off-by: Ilya Dryomov --- drivers/block/rbd.c | 138 +++++++++++++++++++--------------------------------- 1 file changed, 51 insertions(+), 87 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index acda61f5be03..3af09a0f208b 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -337,10 +337,7 @@ struct rbd_img_request { u64 snap_id; /* for reads */ struct ceph_snap_context *snapc; /* for writes */ }; - union { - struct request *rq; /* block request */ - struct rbd_obj_request *obj_request; /* obj req initiator */ - }; + struct rbd_obj_request *obj_request; /* obj req initiator */ struct list_head lock_item; struct list_head object_extents; /* obj_req.ex structs */ @@ -1610,20 +1607,11 @@ static bool rbd_dev_parent_get(struct rbd_device *rbd_dev) return counter > 0; } -/* - * Caller is responsible for filling in the list of object requests - * that comprises the image request, and the Linux request pointer - * (if there is one). - */ -static struct rbd_img_request *rbd_img_request_create( - struct rbd_device *rbd_dev, - enum obj_operation_type op_type) +static void rbd_img_request_init(struct rbd_img_request *img_request, + struct rbd_device *rbd_dev, + enum obj_operation_type op_type) { - struct rbd_img_request *img_request; - - img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO); - if (!img_request) - return NULL; + memset(img_request, 0, sizeof(*img_request)); img_request->rbd_dev = rbd_dev; img_request->op_type = op_type; @@ -1631,8 +1619,6 @@ static struct rbd_img_request *rbd_img_request_create( INIT_LIST_HEAD(&img_request->lock_item); INIT_LIST_HEAD(&img_request->object_extents); mutex_init(&img_request->state_mutex); - - return img_request; } static void rbd_img_capture_header(struct rbd_img_request *img_req) @@ -1667,7 +1653,8 @@ static void rbd_img_request_destroy(struct rbd_img_request *img_request) if (rbd_img_is_write(img_request)) ceph_put_snap_context(img_request->snapc); - kmem_cache_free(rbd_img_request_cache, img_request); + if (test_bit(IMG_REQ_CHILD, &img_request->flags)) + kmem_cache_free(rbd_img_request_cache, img_request); } #define BITS_PER_OBJ 2 @@ -2834,10 +2821,11 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req) struct rbd_img_request *child_img_req; int ret; - child_img_req = rbd_img_request_create(parent, OBJ_OP_READ); + child_img_req = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO); if (!child_img_req) return -ENOMEM; + rbd_img_request_init(child_img_req, parent, OBJ_OP_READ); __set_bit(IMG_REQ_CHILD, &child_img_req->flags); child_img_req->obj_request = obj_req; @@ -3638,7 +3626,7 @@ again: goto again; } } else { - struct request *rq = img_req->rq; + struct request *rq = blk_mq_rq_from_pdu(img_req); rbd_img_request_destroy(img_req); blk_mq_end_request(rq, errno_to_blk_status(result)); @@ -4692,68 +4680,25 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev, static void rbd_queue_workfn(struct work_struct *work) { - struct request *rq = blk_mq_rq_from_pdu(work); - struct rbd_device *rbd_dev = rq->q->queuedata; - struct rbd_img_request *img_request; + struct rbd_img_request *img_request = + container_of(work, struct rbd_img_request, work); + struct rbd_device *rbd_dev = img_request->rbd_dev; + enum obj_operation_type op_type = img_request->op_type; + struct request *rq = blk_mq_rq_from_pdu(img_request); u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT; u64 length = blk_rq_bytes(rq); - enum obj_operation_type op_type; u64 mapping_size; int result; - switch (req_op(rq)) { - case REQ_OP_DISCARD: - op_type = OBJ_OP_DISCARD; - break; - case REQ_OP_WRITE_ZEROES: - op_type = OBJ_OP_ZEROOUT; - break; - case REQ_OP_WRITE: - op_type = OBJ_OP_WRITE; - break; - case REQ_OP_READ: - op_type = OBJ_OP_READ; - break; - default: - dout("%s: non-fs request type %d\n", __func__, req_op(rq)); - result = -EIO; - goto err; - } - /* Ignore/skip any zero-length requests */ - if (!length) { dout("%s: zero-length request\n", __func__); result = 0; - goto err_rq; - } - - if (op_type != OBJ_OP_READ) { - if (rbd_is_ro(rbd_dev)) { - rbd_warn(rbd_dev, "%s on read-only mapping", - obj_op_name(op_type)); - result = -EIO; - goto err; - } - rbd_assert(!rbd_is_snap(rbd_dev)); - } - - if (offset && length > U64_MAX - offset + 1) { - rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset, - length); - result = -EINVAL; - goto err_rq; /* Shouldn't happen */ + goto err_img_request; } blk_mq_start_request(rq); - img_request = rbd_img_request_create(rbd_dev, op_type); - if (!img_request) { - result = -ENOMEM; - goto err_rq; - } - img_request->rq = rq; - down_read(&rbd_dev->header_rwsem); mapping_size = rbd_dev->mapping.size; rbd_img_capture_header(img_request); @@ -4782,21 +4727,50 @@ static void rbd_queue_workfn(struct work_struct *work) err_img_request: rbd_img_request_destroy(img_request); -err_rq: if (result) rbd_warn(rbd_dev, "%s %llx at %llx result %d", obj_op_name(op_type), length, offset, result); -err: blk_mq_end_request(rq, errno_to_blk_status(result)); } static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { - struct request *rq = bd->rq; - struct work_struct *work = blk_mq_rq_to_pdu(rq); + struct rbd_device *rbd_dev = hctx->queue->queuedata; + struct rbd_img_request *img_req = blk_mq_rq_to_pdu(bd->rq); + enum obj_operation_type op_type; - queue_work(rbd_wq, work); + switch (req_op(bd->rq)) { + case REQ_OP_DISCARD: + op_type = OBJ_OP_DISCARD; + break; + case REQ_OP_WRITE_ZEROES: + op_type = OBJ_OP_ZEROOUT; + break; + case REQ_OP_WRITE: + op_type = OBJ_OP_WRITE; + break; + case REQ_OP_READ: + op_type = OBJ_OP_READ; + break; + default: + rbd_warn(rbd_dev, "unknown req_op %d", req_op(bd->rq)); + return BLK_STS_IOERR; + } + + rbd_img_request_init(img_req, rbd_dev, op_type); + + if (rbd_img_is_write(img_req)) { + if (rbd_is_ro(rbd_dev)) { + rbd_warn(rbd_dev, "%s on read-only mapping", + obj_op_name(img_req->op_type)); + return BLK_STS_IOERR; + } + rbd_assert(!rbd_is_snap(rbd_dev)); + } + + INIT_WORK(&img_req->work, rbd_queue_workfn); + queue_work(rbd_wq, &img_req->work); return BLK_STS_OK; } @@ -4963,18 +4937,8 @@ out: return ret; } -static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq, - unsigned int hctx_idx, unsigned int numa_node) -{ - struct work_struct *work = blk_mq_rq_to_pdu(rq); - - INIT_WORK(work, rbd_queue_workfn); - return 0; -} - static const struct blk_mq_ops rbd_mq_ops = { .queue_rq = rbd_queue_rq, - .init_request = rbd_init_request, }; static int rbd_init_disk(struct rbd_device *rbd_dev) @@ -5007,7 +4971,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) rbd_dev->tag_set.numa_node = NUMA_NO_NODE; rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; rbd_dev->tag_set.nr_hw_queues = 1; - rbd_dev->tag_set.cmd_size = sizeof(struct work_struct); + rbd_dev->tag_set.cmd_size = sizeof(struct rbd_img_request); err = blk_mq_alloc_tag_set(&rbd_dev->tag_set); if (err) -- cgit v1.2.3-59-g8ed1b