From 9969ebc5af93028c21f2614621737f0d6ff6fc06 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 18 Jan 2013 12:31:10 -0600 Subject: [PATCH] rbd: implement watch/unwatch with new code Implement a new function to set up or tear down a watch event for an mapped rbd image header using the new request code. Create a new object request type "nodata" to handle this. And define rbd_osd_trivial_callback() which simply marks a request done. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 89 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 86 insertions(+), 3 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 5e7110a5051..60b68512fa9 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -170,7 +170,9 @@ typedef void (*rbd_img_callback_t)(struct rbd_img_request *); struct rbd_obj_request; typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *); -enum obj_request_type { OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES }; +enum obj_request_type { + OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES +}; struct rbd_obj_request { const char *object_name; @@ -1083,6 +1085,7 @@ static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request, static bool obj_request_type_valid(enum obj_request_type type) { switch (type) { + case OBJ_REQUEST_NODATA: case OBJ_REQUEST_BIO: case OBJ_REQUEST_PAGES: return true; @@ -1306,6 +1309,12 @@ static int rbd_obj_request_wait(struct rbd_obj_request *obj_request) return wait_for_completion_interruptible(&obj_request->completion); } +static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request, + struct ceph_osd_op *op) +{ + atomic_set(&obj_request->done, 1); +} + static void rbd_obj_request_complete(struct rbd_obj_request *obj_request) { if (obj_request->callback) @@ -1500,6 +1509,9 @@ static void rbd_osd_req_callback(struct ceph_osd_request *osd_req, case CEPH_OSD_OP_WRITE: rbd_osd_write_callback(obj_request, op); break; + case CEPH_OSD_OP_WATCH: + rbd_osd_trivial_callback(obj_request, op); + break; default: rbd_warn(NULL, "%s: unsupported op %hu\n", obj_request->object_name, (unsigned short) opcode); @@ -1543,6 +1555,8 @@ static struct ceph_osd_request *rbd_osd_req_create( rbd_assert(obj_request_type_valid(obj_request->type)); switch (obj_request->type) { + case OBJ_REQUEST_NODATA: + break; /* Nothing to do */ case OBJ_REQUEST_BIO: rbd_assert(obj_request->bio_list != NULL); osd_req->r_bio = obj_request->bio_list; @@ -1635,6 +1649,8 @@ static void rbd_obj_request_destroy(struct kref *kref) rbd_assert(obj_request_type_valid(obj_request->type)); switch (obj_request->type) { + case OBJ_REQUEST_NODATA: + break; /* Nothing to do */ case OBJ_REQUEST_BIO: if (obj_request->bio_list) bio_chain_put(obj_request->bio_list); @@ -1862,6 +1878,72 @@ static int rbd_img_request_submit(struct rbd_img_request *img_request) return 0; } +/* + * Request sync osd watch/unwatch. The value of "start" determines + * whether a watch request is being initiated or torn down. + */ +static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start) +{ + struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; + struct rbd_obj_request *obj_request; + struct ceph_osd_req_op *op; + int ret; + + rbd_assert(start ^ !!rbd_dev->watch_event); + rbd_assert(start ^ !!rbd_dev->watch_request); + + if (start) { + ret = ceph_osdc_create_event(osdc, rbd_watch_cb, 0, rbd_dev, + &rbd_dev->watch_event); + if (ret < 0) + return ret; + } + + ret = -ENOMEM; + obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0, + OBJ_REQUEST_NODATA); + if (!obj_request) + goto out_cancel; + + op = rbd_osd_req_op_create(CEPH_OSD_OP_WATCH, + rbd_dev->watch_event->cookie, + rbd_dev->header.obj_version, start); + if (!op) + goto out_cancel; + obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, + obj_request, op); + rbd_osd_req_op_destroy(op); + if (!obj_request->osd_req) + goto out_cancel; + + if (start) { + rbd_dev->watch_request = obj_request->osd_req; + ceph_osdc_set_request_linger(osdc, rbd_dev->watch_request); + } + ret = rbd_obj_request_submit(osdc, obj_request); + if (ret) + goto out_cancel; + ret = rbd_obj_request_wait(obj_request); + if (ret) + goto out_cancel; + + ret = obj_request->result; + if (ret) + goto out_cancel; + + if (start) + goto done; /* Done if setting up the watch request */ +out_cancel: + /* Cancel the event if we're tearing down, or on error */ + ceph_osdc_cancel_event(rbd_dev->watch_event); + rbd_dev->watch_event = NULL; +done: + if (obj_request) + rbd_obj_request_put(obj_request); + + return ret; +} + static void rbd_request_fn(struct request_queue *q) { struct rbd_device *rbd_dev = q->queuedata; @@ -3879,7 +3961,8 @@ static int rbd_dev_probe_finish(struct rbd_device *rbd_dev) if (ret) goto err_out_bus; - ret = rbd_req_sync_watch(rbd_dev, 1); + (void) rbd_req_sync_watch; /* avoid a warning */ + ret = rbd_dev_header_watch_sync(rbd_dev, 1); if (ret) goto err_out_bus; @@ -4042,7 +4125,7 @@ static void rbd_dev_release(struct device *dev) rbd_dev->watch_request); } if (rbd_dev->watch_event) - rbd_req_sync_watch(rbd_dev, 0); + rbd_dev_header_watch_sync(rbd_dev, 0); /* clean up and free blkdev */ rbd_free_disk(rbd_dev); -- 2.46.0