diff options
| -rw-r--r-- | drivers/block/rbd.c | 194 |
1 files changed, 137 insertions, 57 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 9c6be82353c0..51dd1b99c242 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -203,6 +203,11 @@ struct rbd_client { struct list_head node; }; +struct pending_result { + int result; /* first nonzero result */ + int num_pending; +}; + struct rbd_img_request; enum obj_request_type { @@ -295,11 +300,18 @@ enum img_req_flags { IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */ }; +enum rbd_img_state { + RBD_IMG_START = 1, + __RBD_IMG_OBJECT_REQUESTS, + RBD_IMG_OBJECT_REQUESTS, +}; + struct rbd_img_request { struct rbd_device *rbd_dev; enum obj_operation_type op_type; enum obj_request_type data_type; unsigned long flags; + enum rbd_img_state state; union { u64 snap_id; /* for reads */ struct ceph_snap_context *snapc; /* for writes */ @@ -308,12 +320,13 @@ struct rbd_img_request { struct request *rq; /* block request */ struct rbd_obj_request *obj_request; /* obj req initiator */ }; - spinlock_t completion_lock; - int result; /* first nonzero obj_request result */ struct list_head object_extents; /* obj_req.ex structs */ - u32 pending_count; + struct mutex state_mutex; + struct pending_result pending; + struct work_struct work; + int work_result; struct kref kref; }; @@ -592,6 +605,23 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id, u64 *snap_features); static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result); +static void rbd_img_handle_request(struct rbd_img_request *img_req, int result); + +/* + * Return true if nothing else is pending. + */ +static bool pending_result_dec(struct pending_result *pending, int *result) +{ + rbd_assert(pending->num_pending > 0); + + if (*result && !pending->result) + pending->result = *result; + if (--pending->num_pending) + return false; + + *result = pending->result; + return true; +} static int rbd_open(struct block_device *bdev, fmode_t mode) { @@ -1350,13 +1380,6 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request) kref_put(&obj_request->kref, rbd_obj_request_destroy); } -static void rbd_img_request_get(struct rbd_img_request *img_request) -{ - dout("%s: img %p (was %d)\n", __func__, img_request, - kref_read(&img_request->kref)); - kref_get(&img_request->kref); -} - static void rbd_img_request_destroy(struct kref *kref); static void rbd_img_request_put(struct rbd_img_request *img_request) { @@ -1373,7 +1396,6 @@ static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request, /* Image request now owns object's original reference */ obj_request->img_request = img_request; - img_request->pending_count++; dout("%s: img %p obj %p\n", __func__, img_request, obj_request); } @@ -1694,8 +1716,8 @@ static struct rbd_img_request *rbd_img_request_create( if (rbd_dev_parent_get(rbd_dev)) img_request_layered_set(img_request); - spin_lock_init(&img_request->completion_lock); INIT_LIST_HEAD(&img_request->object_extents); + mutex_init(&img_request->state_mutex); kref_init(&img_request->kref); dout("%s: rbd_dev %p %s -> img %p\n", __func__, rbd_dev, @@ -2061,7 +2083,6 @@ static int __rbd_img_fill_request(struct rbd_img_request *img_req) if (ret < 0) return ret; if (ret > 0) { - img_req->pending_count--; rbd_img_obj_request_del(img_req, obj_req); continue; } @@ -2071,6 +2092,7 @@ static int __rbd_img_fill_request(struct rbd_img_request *img_req) return ret; } + img_req->state = RBD_IMG_START; return 0; } @@ -2359,17 +2381,19 @@ static int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req, &it); } -static void rbd_img_request_submit(struct rbd_img_request *img_request) +static void rbd_img_handle_request_work(struct work_struct *work) { - struct rbd_obj_request *obj_request; + struct rbd_img_request *img_req = + container_of(work, struct rbd_img_request, work); - dout("%s: img %p\n", __func__, img_request); - - rbd_img_request_get(img_request); - for_each_obj_request(img_request, obj_request) - rbd_obj_handle_request(obj_request, 0); + rbd_img_handle_request(img_req, img_req->work_result); +} - rbd_img_request_put(img_request); +static void rbd_img_schedule(struct rbd_img_request *img_req, int result) +{ + INIT_WORK(&img_req->work, rbd_img_handle_request_work); + img_req->work_result = result; + queue_work(rbd_wq, &img_req->work); } static int rbd_obj_read_object(struct rbd_obj_request *obj_req) @@ -2421,7 +2445,8 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req) return ret; } - rbd_img_request_submit(child_img_req); + /* avoid parent chain recursion */ + rbd_img_schedule(child_img_req, 0); return 0; } @@ -2756,6 +2781,7 @@ static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req, int *result) { struct rbd_img_request *img_req = obj_req->img_request; + struct rbd_device *rbd_dev = img_req->rbd_dev; bool done; mutex_lock(&obj_req->state_mutex); @@ -2765,59 +2791,113 @@ static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req, done = rbd_obj_advance_write(obj_req, result); mutex_unlock(&obj_req->state_mutex); + if (done && *result) { + rbd_assert(*result < 0); + rbd_warn(rbd_dev, "%s at objno %llu %llu~%llu result %d", + obj_op_name(img_req->op_type), obj_req->ex.oe_objno, + obj_req->ex.oe_off, obj_req->ex.oe_len, *result); + } return done; } -static void rbd_obj_end_request(struct rbd_obj_request *obj_req, int result) +/* + * This is open-coded in rbd_img_handle_request() to avoid parent chain + * recursion. + */ +static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result) +{ + if (__rbd_obj_handle_request(obj_req, &result)) + rbd_img_handle_request(obj_req->img_request, result); +} + +static void rbd_img_object_requests(struct rbd_img_request *img_req) { - struct rbd_img_request *img_req = obj_req->img_request; + struct rbd_obj_request *obj_req; - rbd_assert(result <= 0); - if (!result) - return; + rbd_assert(!img_req->pending.result && !img_req->pending.num_pending); + + for_each_obj_request(img_req, obj_req) { + int result = 0; - rbd_warn(img_req->rbd_dev, "%s at objno %llu %llu~%llu result %d", - obj_op_name(img_req->op_type), obj_req->ex.oe_objno, - obj_req->ex.oe_off, obj_req->ex.oe_len, result); - if (!img_req->result) - img_req->result = result; + if (__rbd_obj_handle_request(obj_req, &result)) { + if (result) { + img_req->pending.result = result; + return; + } + } else { + img_req->pending.num_pending++; + } + } } -static void rbd_img_end_request(struct rbd_img_request *img_req) +static bool rbd_img_advance(struct rbd_img_request *img_req, int *result) { - rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags)); +again: + switch (img_req->state) { + case RBD_IMG_START: + rbd_assert(!*result); - blk_mq_end_request(img_req->rq, - errno_to_blk_status(img_req->result)); - rbd_img_request_put(img_req); + rbd_img_object_requests(img_req); + if (!img_req->pending.num_pending) { + *result = img_req->pending.result; + img_req->state = RBD_IMG_OBJECT_REQUESTS; + goto again; + } + img_req->state = __RBD_IMG_OBJECT_REQUESTS; + return false; + case __RBD_IMG_OBJECT_REQUESTS: + if (!pending_result_dec(&img_req->pending, result)) + return false; + /* fall through */ + case RBD_IMG_OBJECT_REQUESTS: + return true; + default: + BUG(); + } } -static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result) +/* + * Return true if @img_req is completed. + */ +static bool __rbd_img_handle_request(struct rbd_img_request *img_req, + int *result) { - struct rbd_img_request *img_req; + struct rbd_device *rbd_dev = img_req->rbd_dev; + bool done; -again: - if (!__rbd_obj_handle_request(obj_req, &result)) - return; + mutex_lock(&img_req->state_mutex); + done = rbd_img_advance(img_req, result); + mutex_unlock(&img_req->state_mutex); - img_req = obj_req->img_request; - spin_lock(&img_req->completion_lock); - rbd_obj_end_request(obj_req, result); - rbd_assert(img_req->pending_count); - if (--img_req->pending_count) { - spin_unlock(&img_req->completion_lock); - return; + if (done && *result) { + rbd_assert(*result < 0); + rbd_warn(rbd_dev, "%s%s result %d", + test_bit(IMG_REQ_CHILD, &img_req->flags) ? "child " : "", + obj_op_name(img_req->op_type), *result); } + return done; +} + +static void rbd_img_handle_request(struct rbd_img_request *img_req, int result) +{ +again: + if (!__rbd_img_handle_request(img_req, &result)) + return; - spin_unlock(&img_req->completion_lock); - rbd_assert(img_req->result <= 0); if (test_bit(IMG_REQ_CHILD, &img_req->flags)) { - obj_req = img_req->obj_request; - result = img_req->result; + struct rbd_obj_request *obj_req = img_req->obj_request; + rbd_img_request_put(img_req); - goto again; + if (__rbd_obj_handle_request(obj_req, &result)) { + img_req = obj_req->img_request; + goto again; + } + } else { + struct request *rq = img_req->rq; + + rbd_img_request_put(img_req); + blk_mq_end_request(rq, errno_to_blk_status(result)); } - rbd_img_end_request(img_req); } static const struct rbd_client_id rbd_empty_cid; @@ -3933,10 +4013,10 @@ static void rbd_queue_workfn(struct work_struct *work) else result = rbd_img_fill_from_bio(img_request, offset, length, rq->bio); - if (result || !img_request->pending_count) + if (result) goto err_img_request; - rbd_img_request_submit(img_request); + rbd_img_handle_request(img_request, 0); if (must_be_locked) up_read(&rbd_dev->lock_rwsem); return; |