On 04/26/2013 11:00 AM, Alex Elder wrote:
Encapsulate the creation of a snapshot context for rbd in a new
function rbd_snap_context_create(). Define rbd wrappers for getting
and dropping references to them once they're created.
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
drivers/block/rbd.c | 65
++++++++++++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 26 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index fe84975..63040fd 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -671,6 +671,35 @@ static void rbd_client_release(struct kref *kref)
kfree(rbdc);
}
+/* Caller has to fill in snapc->seq and snapc->snaps[0..snap_count-1] */
+
+static struct ceph_snap_context *rbd_snap_context_create(u32 snap_count)
+{
+ struct ceph_snap_context *snapc;
+ size_t size;
+
+ size = sizeof (struct ceph_snap_context);
+ size += snap_count * sizeof (snapc->snaps[0]);
+ snapc = kzalloc(size, GFP_KERNEL);
+ if (!snapc)
+ return NULL;
+
+ atomic_set(&snapc->nref, 1);
+ snapc->num_snaps = snap_count;
+
+ return snapc;
+}
It seems like this should go in libceph.h, alongside
ceph_[get|put]_snap_context(). fs/ceph/snap.c has very similar code too.
I wouldn't expect rbd to need anything specialized with its snapshot
contexts.
+static inline void rbd_snap_context_get(struct ceph_snap_context *snapc)
+{
+ (void)ceph_get_snap_context(snapc);
+}
+
+static inline void rbd_snap_context_put(struct ceph_snap_context *snapc)
+{
+ ceph_put_snap_context(snapc);
+}
+
/*
* Drop reference to ceph client node. If it's not referenced anymore,
release
* it.
@@ -789,18 +818,13 @@ static int rbd_header_from_disk(struct
rbd_image_header *header,
/* Allocate and fill in the snapshot context */
header->image_size = le64_to_cpu(ondisk->image_size);
- size = sizeof (struct ceph_snap_context);
- size += snap_count * sizeof (header->snapc->snaps[0]);
- header->snapc = kzalloc(size, GFP_KERNEL);
+
+ header->snapc = rbd_snap_context_create(snap_count);
if (!header->snapc)
goto out_err;
-
- atomic_set(&header->snapc->nref, 1);
header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
- header->snapc->num_snaps = snap_count;
for (i = 0; i < snap_count; i++)
- header->snapc->snaps[i] =
- le64_to_cpu(ondisk->snaps[i].id);
+ header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id);
return 0;
@@ -870,7 +894,7 @@ static void rbd_header_free(struct rbd_image_header
*header)
header->snap_sizes = NULL;
kfree(header->snap_names);
header->snap_names = NULL;
- ceph_put_snap_context(header->snapc);
+ rbd_snap_context_put(header->snapc);
header->snapc = NULL;
}
@@ -1720,7 +1744,6 @@ static struct rbd_img_request *rbd_img_request_create(
bool child_request)
{
struct rbd_img_request *img_request;
- struct ceph_snap_context *snapc = NULL;
img_request = kmalloc(sizeof (*img_request), GFP_ATOMIC);
if (!img_request)
@@ -1728,13 +1751,8 @@ static struct rbd_img_request
*rbd_img_request_create(
if (write_request) {
down_read(&rbd_dev->header_rwsem);
- snapc = ceph_get_snap_context(rbd_dev->header.snapc);
+ rbd_snap_context_get(rbd_dev->header.snapc);
up_read(&rbd_dev->header_rwsem);
- if (WARN_ON(!snapc)) {
- kfree(img_request);
- return NULL; /* Shouldn't happen */
- }
-
}
img_request->rq = NULL;
@@ -1744,7 +1762,7 @@ static struct rbd_img_request *rbd_img_request_create(
img_request->flags = 0;
if (write_request) {
img_request_write_set(img_request);
- img_request->snapc = snapc;
+ img_request->snapc = rbd_dev->header.snapc;
} else {
img_request->snap_id = rbd_dev->spec->snap_id;
}
@@ -1785,7 +1803,7 @@ static void rbd_img_request_destroy(struct kref *kref)
rbd_assert(img_request->obj_request_count == 0);
if (img_request_write_test(img_request))
- ceph_put_snap_context(img_request->snapc);
+ rbd_snap_context_put(img_request->snapc);
if (img_request_child_test(img_request))
rbd_obj_request_put(img_request->obj_request);
@@ -3049,7 +3067,7 @@ static int rbd_dev_v1_refresh(struct rbd_device
*rbd_dev, u64 *hver)
kfree(rbd_dev->header.snap_sizes);
kfree(rbd_dev->header.snap_names);
/* osd requests may still refer to snapc */
- ceph_put_snap_context(rbd_dev->header.snapc);
+ rbd_snap_context_put(rbd_dev->header.snapc);
if (hver)
*hver = h.obj_version;
@@ -3889,19 +3907,14 @@ static int rbd_dev_v2_snap_context(struct
rbd_device *rbd_dev, u64 *ver)
}
if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
goto out;
+ ret = 0;
- size = sizeof (struct ceph_snap_context) +
- snap_count * sizeof (snapc->snaps[0]);
- snapc = kmalloc(size, GFP_KERNEL);
+ snapc = rbd_snap_context_create(snap_count);
if (!snapc) {
ret = -ENOMEM;
goto out;
}
- ret = 0;
-
- atomic_set(&snapc->nref, 1);
snapc->seq = seq;
- snapc->num_snaps = snap_count;
for (i = 0; i < snap_count; i++)
snapc->snaps[i] = ceph_decode_64(&p);
--
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