From e93f3152357ca75284284bef8eeea7d45fe1bab1 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 8 May 2013 22:50:04 -0500 Subject: [PATCH] rbd: define parent image request routines Define rbd_parent_request_create() and rbd_parent_request_destroy() to handle the creation of parent image requests submitted for layered image objects. For simplicity, let rbd_img_request_put() handle dropping the reference to any image request (parent or not), and call whichever destructor is appropriate on the last put. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 78 ++++++++++++++++++++++++++++++++------------- 1 file changed, 55 insertions(+), 23 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 9c2b20a88be..1ffdfbfbf3c 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1359,13 +1359,18 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request) kref_put(&obj_request->kref, rbd_obj_request_destroy); } +static bool img_request_child_test(struct rbd_img_request *img_request); +static void rbd_parent_request_destroy(struct kref *kref); static void rbd_img_request_destroy(struct kref *kref); static void rbd_img_request_put(struct rbd_img_request *img_request) { rbd_assert(img_request != NULL); dout("%s: img %p (was %d)\n", __func__, img_request, atomic_read(&img_request->kref.refcount)); - kref_put(&img_request->kref, rbd_img_request_destroy); + if (img_request_child_test(img_request)) + kref_put(&img_request->kref, rbd_parent_request_destroy); + else + kref_put(&img_request->kref, rbd_img_request_destroy); } static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request, @@ -1482,6 +1487,12 @@ static void img_request_child_set(struct rbd_img_request *img_request) smp_mb(); } +static void img_request_child_clear(struct rbd_img_request *img_request) +{ + clear_bit(IMG_REQ_CHILD, &img_request->flags); + smp_mb(); +} + static bool img_request_child_test(struct rbd_img_request *img_request) { smp_mb(); @@ -1856,8 +1867,7 @@ static void rbd_dev_unparent(struct rbd_device *rbd_dev) static struct rbd_img_request *rbd_img_request_create( struct rbd_device *rbd_dev, u64 offset, u64 length, - bool write_request, - bool child_request) + bool write_request) { struct rbd_img_request *img_request; @@ -1882,8 +1892,6 @@ static struct rbd_img_request *rbd_img_request_create( } else { img_request->snap_id = rbd_dev->spec->snap_id; } - if (child_request) - img_request_child_set(img_request); if (rbd_dev->parent_overlap) img_request_layered_set(img_request); spin_lock_init(&img_request->completion_lock); @@ -1918,12 +1926,46 @@ static void rbd_img_request_destroy(struct kref *kref) if (img_request_write_test(img_request)) ceph_put_snap_context(img_request->snapc); - if (img_request_child_test(img_request)) - rbd_obj_request_put(img_request->obj_request); - kmem_cache_free(rbd_img_request_cache, img_request); } +static struct rbd_img_request *rbd_parent_request_create( + struct rbd_obj_request *obj_request, + u64 img_offset, u64 length) +{ + struct rbd_img_request *parent_request; + struct rbd_device *rbd_dev; + + rbd_assert(obj_request->img_request); + rbd_dev = obj_request->img_request->rbd_dev; + + parent_request = rbd_img_request_create(rbd_dev->parent, + img_offset, length, false); + if (!parent_request) + return NULL; + + img_request_child_set(parent_request); + rbd_obj_request_get(obj_request); + parent_request->obj_request = obj_request; + + return parent_request; +} + +static void rbd_parent_request_destroy(struct kref *kref) +{ + struct rbd_img_request *parent_request; + struct rbd_obj_request *orig_request; + + parent_request = container_of(kref, struct rbd_img_request, kref); + orig_request = parent_request->obj_request; + + parent_request->obj_request = NULL; + rbd_obj_request_put(orig_request); + img_request_child_clear(parent_request); + + rbd_img_request_destroy(kref); +} + static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request) { struct rbd_img_request *img_request; @@ -2321,13 +2363,10 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) } result = -ENOMEM; - parent_request = rbd_img_request_create(rbd_dev->parent, - img_offset, length, - false, true); + parent_request = rbd_parent_request_create(obj_request, + img_offset, length); if (!parent_request) goto out_err; - rbd_obj_request_get(obj_request); - parent_request->obj_request = obj_request; result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages); if (result) @@ -2580,7 +2619,6 @@ out: static void rbd_img_parent_read(struct rbd_obj_request *obj_request) { - struct rbd_device *rbd_dev; struct rbd_img_request *img_request; int result; @@ -2589,20 +2627,14 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request) rbd_assert(obj_request->result == (s32) -ENOENT); rbd_assert(obj_request_type_valid(obj_request->type)); - rbd_dev = obj_request->img_request->rbd_dev; - rbd_assert(rbd_dev->parent != NULL); /* rbd_read_finish(obj_request, obj_request->length); */ - img_request = rbd_img_request_create(rbd_dev->parent, + img_request = rbd_parent_request_create(obj_request, obj_request->img_offset, - obj_request->length, - false, true); + obj_request->length); result = -ENOMEM; if (!img_request) goto out_err; - rbd_obj_request_get(obj_request); - img_request->obj_request = obj_request; - if (obj_request->type == OBJ_REQUEST_BIO) result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO, obj_request->bio_list); @@ -2913,7 +2945,7 @@ static void rbd_request_fn(struct request_queue *q) result = -ENOMEM; img_request = rbd_img_request_create(rbd_dev, offset, length, - write_request, false); + write_request); if (!img_request) goto end_request; -- 2.43.2