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authorAlex Elder <elder@inktank.com>2013-05-09 07:50:04 +0400
committerAlex Elder <elder@inktank.com>2013-05-14 00:06:44 +0400
commite93f3152357ca75284284bef8eeea7d45fe1bab1 (patch)
tree772595e38dcf482119c938228c2e4db699bcbaa3 /drivers/block
parentfb65d2284c117cfc28d30217d25a14a8e7a75a94 (diff)
downloadlinux-e93f3152357ca75284284bef8eeea7d45fe1bab1.tar.xz
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 <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/rbd.c78
1 files changed, 55 insertions, 23 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 9c2b20a88be2..1ffdfbfbf3c4 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;