From 54ab3b24c536bc9b45ab444830974c6bea57778e Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Sat, 11 May 2019 16:21:49 +0200 Subject: [PATCH] rbd: get rid of obj_req->xferred, obj_req->result and img_req->xferred obj_req->xferred and img_req->xferred don't bring any value. The former is used for short reads and has to be set to obj_req->ex.oe_len after that and elsewhere. The latter is just an aggregate. Use result for short reads (>=0 - number of bytes read, <0 - error) and pass it around explicitly. No need to store it in obj_req. Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang --- drivers/block/rbd.c | 149 +++++++++++++++++--------------------------- 1 file changed, 58 insertions(+), 91 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index e5009a34f9c2..a9b0b23148f9 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -276,9 +276,6 @@ struct rbd_obj_request { struct ceph_osd_request *osd_req; - u64 xferred; /* bytes transferred */ - int result; - struct kref kref; }; @@ -301,7 +298,6 @@ struct rbd_img_request { struct rbd_obj_request *obj_request; /* obj req initiator */ }; spinlock_t completion_lock; - u64 xferred;/* aggregate bytes transferred */ int result; /* first nonzero obj_request result */ struct list_head object_extents; /* obj_req.ex structs */ @@ -584,6 +580,8 @@ static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id, 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 int rbd_open(struct block_device *bdev, fmode_t mode) { struct rbd_device *rbd_dev = bdev->bd_disk->private_data; @@ -1317,6 +1315,8 @@ static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes) static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off, u32 bytes) { + dout("%s %p data buf %u~%u\n", __func__, obj_req, off, bytes); + switch (obj_req->img_request->data_type) { case OBJ_REQUEST_BIO: zero_bios(&obj_req->bio_pos, off, bytes); @@ -1457,28 +1457,26 @@ static bool rbd_img_is_write(struct rbd_img_request *img_req) } } -static void rbd_obj_handle_request(struct rbd_obj_request *obj_req); - static void rbd_osd_req_callback(struct ceph_osd_request *osd_req) { struct rbd_obj_request *obj_req = osd_req->r_priv; + int result; dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req, osd_req->r_result, obj_req); rbd_assert(osd_req == obj_req->osd_req); - obj_req->result = osd_req->r_result < 0 ? osd_req->r_result : 0; - if (!obj_req->result && !rbd_img_is_write(obj_req->img_request)) - obj_req->xferred = osd_req->r_result; + /* + * Writes aren't allowed to return a data payload. In some + * guarded write cases (e.g. stat + zero on an empty object) + * a stat response makes it through, but we don't care. + */ + if (osd_req->r_result > 0 && rbd_img_is_write(obj_req->img_request)) + result = 0; else - /* - * Writes aren't allowed to return a data payload. In some - * guarded write cases (e.g. stat + zero on an empty object) - * a stat response makes it through, but we don't care. - */ - obj_req->xferred = 0; + result = osd_req->r_result; - rbd_obj_handle_request(obj_req); + rbd_obj_handle_request(obj_req, result); } static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request) @@ -2041,7 +2039,6 @@ static int __rbd_img_fill_request(struct rbd_img_request *img_req) if (ret < 0) return ret; if (ret > 0) { - img_req->xferred += obj_req->ex.oe_len; img_req->pending_count--; rbd_img_obj_request_del(img_req, obj_req); continue; @@ -2400,17 +2397,17 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req) return 0; } -static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req) +static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req, int *result) { struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev; int ret; - if (obj_req->result == -ENOENT && + if (*result == -ENOENT && rbd_dev->parent_overlap && !obj_req->tried_parent) { /* reverse map this object extent onto the parent */ ret = rbd_obj_calc_img_extents(obj_req, false); if (ret) { - obj_req->result = ret; + *result = ret; return true; } @@ -2418,7 +2415,7 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req) obj_req->tried_parent = true; ret = rbd_obj_read_from_parent(obj_req); if (ret) { - obj_req->result = ret; + *result = ret; return true; } return false; @@ -2428,16 +2425,18 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req) /* * -ENOENT means a hole in the image -- zero-fill the entire * length of the request. A short read also implies zero-fill - * to the end of the request. In both cases we update xferred - * count to indicate the whole request was satisfied. + * to the end of the request. */ - if (obj_req->result == -ENOENT || - (!obj_req->result && obj_req->xferred < obj_req->ex.oe_len)) { - rbd_assert(!obj_req->xferred || !obj_req->result); - rbd_obj_zero_range(obj_req, obj_req->xferred, - obj_req->ex.oe_len - obj_req->xferred); - obj_req->result = 0; - obj_req->xferred = obj_req->ex.oe_len; + if (*result == -ENOENT) { + rbd_obj_zero_range(obj_req, 0, obj_req->ex.oe_len); + *result = 0; + } else if (*result >= 0) { + if (*result < obj_req->ex.oe_len) + rbd_obj_zero_range(obj_req, *result, + obj_req->ex.oe_len - *result); + else + rbd_assert(*result == obj_req->ex.oe_len); + *result = 0; } return true; @@ -2635,14 +2634,13 @@ static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req) return rbd_obj_read_from_parent(obj_req); } -static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req) +static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req, int *result) { int ret; switch (obj_req->write_state) { case RBD_OBJ_WRITE_GUARD: - rbd_assert(!obj_req->xferred); - if (obj_req->result == -ENOENT) { + if (*result == -ENOENT) { /* * The target object doesn't exist. Read the data for * the entire target object up to the overlap point (if @@ -2650,7 +2648,7 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req) */ ret = rbd_obj_handle_write_guard(obj_req); if (ret) { - obj_req->result = ret; + *result = ret; return true; } return false; @@ -2658,33 +2656,26 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req) /* 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 - * write -- indicate the whole request was satisfied. - */ - obj_req->xferred = obj_req->ex.oe_len; return true; case RBD_OBJ_WRITE_READ_FROM_PARENT: - if (obj_req->result) + if (*result < 0) return true; - rbd_assert(obj_req->xferred); - ret = rbd_obj_issue_copyup(obj_req, obj_req->xferred); + rbd_assert(*result); + ret = rbd_obj_issue_copyup(obj_req, *result); if (ret) { - obj_req->result = ret; - obj_req->xferred = 0; + *result = ret; return true; } return false; case RBD_OBJ_WRITE_COPYUP_EMPTY_SNAPC: - if (obj_req->result) + if (*result) return true; obj_req->write_state = RBD_OBJ_WRITE_COPYUP_OPS; ret = rbd_obj_issue_copyup_ops(obj_req, MODS_ONLY); if (ret) { - obj_req->result = ret; + *result = ret; return true; } return false; @@ -2696,24 +2687,23 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req) /* * Returns true if @obj_req is completed, or false otherwise. */ -static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req) +static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req, + int *result) { switch (obj_req->img_request->op_type) { case OBJ_OP_READ: - return rbd_obj_handle_read(obj_req); + return rbd_obj_handle_read(obj_req, result); case OBJ_OP_WRITE: - return rbd_obj_handle_write(obj_req); + return rbd_obj_handle_write(obj_req, result); case OBJ_OP_DISCARD: case OBJ_OP_ZEROOUT: - if (rbd_obj_handle_write(obj_req)) { + if (rbd_obj_handle_write(obj_req, result)) { /* * Hide -ENOENT from delete/truncate/zero -- discarding * a non-existent object is not a problem. */ - if (obj_req->result == -ENOENT) { - obj_req->result = 0; - obj_req->xferred = obj_req->ex.oe_len; - } + if (*result == -ENOENT) + *result = 0; return true; } return false; @@ -2722,66 +2712,41 @@ static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req) } } -static void rbd_obj_end_request(struct rbd_obj_request *obj_req) +static void rbd_obj_end_request(struct rbd_obj_request *obj_req, int result) { struct rbd_img_request *img_req = obj_req->img_request; - rbd_assert((!obj_req->result && - obj_req->xferred == obj_req->ex.oe_len) || - (obj_req->result < 0 && !obj_req->xferred)); - if (!obj_req->result) { - img_req->xferred += obj_req->xferred; + rbd_assert(result <= 0); + if (!result) return; - } - rbd_warn(img_req->rbd_dev, - "%s at objno %llu %llu~%llu result %d xferred %llu", + 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, obj_req->result, - obj_req->xferred); - if (!img_req->result) { - img_req->result = obj_req->result; - img_req->xferred = 0; - } -} - -static void rbd_img_end_child_request(struct rbd_img_request *img_req) -{ - struct rbd_obj_request *obj_req = img_req->obj_request; - - rbd_assert(test_bit(IMG_REQ_CHILD, &img_req->flags)); - rbd_assert((!img_req->result && - img_req->xferred == rbd_obj_img_extents_bytes(obj_req)) || - (img_req->result < 0 && !img_req->xferred)); - - obj_req->result = img_req->result; - obj_req->xferred = img_req->xferred; - rbd_img_request_put(img_req); + obj_req->ex.oe_off, obj_req->ex.oe_len, result); + if (!img_req->result) + img_req->result = result; } static void rbd_img_end_request(struct rbd_img_request *img_req) { rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags)); - rbd_assert((!img_req->result && - img_req->xferred == blk_rq_bytes(img_req->rq)) || - (img_req->result < 0 && !img_req->xferred)); blk_mq_end_request(img_req->rq, errno_to_blk_status(img_req->result)); rbd_img_request_put(img_req); } -static void rbd_obj_handle_request(struct rbd_obj_request *obj_req) +static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result) { struct rbd_img_request *img_req; again: - if (!__rbd_obj_handle_request(obj_req)) + if (!__rbd_obj_handle_request(obj_req, &result)) return; img_req = obj_req->img_request; spin_lock(&img_req->completion_lock); - rbd_obj_end_request(obj_req); + rbd_obj_end_request(obj_req, result); rbd_assert(img_req->pending_count); if (--img_req->pending_count) { spin_unlock(&img_req->completion_lock); @@ -2789,9 +2754,11 @@ again: } 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; - rbd_img_end_child_request(img_req); + result = img_req->result ?: rbd_obj_img_extents_bytes(obj_req); + rbd_img_request_put(img_req); goto again; } rbd_img_end_request(img_req); -- 2.34.1