On Mon, Jul 29, 2019 at 11:43 AM Dongsheng Yang
<dongsheng.yang@xxxxxxxxxxxx> wrote:
>
> rbd_journal_allocate_tag() get the client by client id and allocate an uniq tag
> for this client.
>
> All journal events from this client will be tagged by this tag.
>
> Signed-off-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
> ---
> drivers/block/rbd.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 112 insertions(+)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 337a20f..86008f2 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -28,16 +28,19 @@
>
> */
>
> +#include <linux/crc32c.h>
What is this include for?
> #include <linux/ceph/libceph.h>
> #include <linux/ceph/osd_client.h>
> #include <linux/ceph/mon_client.h>
> #include <linux/ceph/cls_lock_client.h>
> #include <linux/ceph/striper.h>
> #include <linux/ceph/decode.h>
> +#include <linux/ceph/journaler.h>
> #include <linux/parser.h>
> #include <linux/bsearch.h>
>
> #include <linux/kernel.h>
> +#include <linux/bio.h>
Same here.
> #include <linux/device.h>
> #include <linux/module.h>
> #include <linux/blk-mq.h>
> @@ -470,6 +473,14 @@ enum rbd_dev_flags {
> RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
> };
>
> +#define LOCAL_MIRROR_UUID ""
> +#define LOCAL_CLIENT_ID ""
> +
> +struct rbd_journal {
> + struct ceph_journaler *journaler;
> + uint64_t tag_tid;
> +};
I think these two fields can be embedded into struct rbd_device
directly.
> +
> static DEFINE_MUTEX(client_mutex); /* Serialize client creation */
>
> static LIST_HEAD(rbd_dev_list); /* devices */
> @@ -6916,6 +6927,107 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev)
> return ret;
> }
>
> +typedef struct rbd_journal_tag_predecessor {
> + bool commit_valid;
> + uint64_t tag_tid;
> + uint64_t entry_tid;
> + uint32_t uuid_len;
> + char *mirror_uuid;
> +} rbd_journal_tag_predecessor;
> +
> +typedef struct rbd_journal_tag_data {
> + struct rbd_journal_tag_predecessor predecessor;
> + uint32_t uuid_len;
> + char *mirror_uuid;
> +} rbd_journal_tag_data;
Why typedef these structs?
> +
> +static uint32_t tag_data_encoding_size(struct rbd_journal_tag_data *tag_data)
> +{
> + // sizeof(uuid_len) 4 + uuid_len + 1 commit_valid + 8 tag_tid +
> + // 8 entry_tid + 4 sizeof(uuid_len) + uuid_len
> + return (4 + tag_data->uuid_len + 1 + 8 + 8 + 4 +
> + tag_data->predecessor.uuid_len);
> +}
> +
> +static void predecessor_encode(void **p, void *end,
> + struct rbd_journal_tag_predecessor *predecessor)
> +{
> + ceph_encode_string(p, end, predecessor->mirror_uuid,
> + predecessor->uuid_len);
> + ceph_encode_8(p, predecessor->commit_valid);
> + ceph_encode_64(p, predecessor->tag_tid);
> + ceph_encode_64(p, predecessor->entry_tid);
> +}
> +
> +static int rbd_journal_encode_tag_data(void **p, void *end,
> + struct rbd_journal_tag_data *tag_data)
> +{
> + struct rbd_journal_tag_predecessor *predecessor = &tag_data->predecessor;
> +
> + ceph_encode_string(p, end, tag_data->mirror_uuid, tag_data->uuid_len);
> + predecessor_encode(p, end, predecessor);
> +
> + return 0;
> +}
> +
> +static int rbd_journal_allocate_tag(struct rbd_journal *journal)
> +{
> + struct ceph_journaler_tag tag = {};
> + struct rbd_journal_tag_data tag_data = {};
> + struct ceph_journaler *journaler = journal->journaler;
> + struct ceph_journaler_client *client;
> + struct rbd_journal_tag_predecessor *predecessor;
> + struct ceph_journaler_object_pos *position;
> + void *orig_buf, *buf, *p, *end;
> + uint32_t buf_len;
> + int ret;
> +
> + ret = ceph_journaler_get_cached_client(journaler, LOCAL_CLIENT_ID, &client);
> + if (ret)
> + goto out;
> +
> + position = list_first_entry(&client->object_positions,
> + struct ceph_journaler_object_pos, node);
> +
> + predecessor = &tag_data.predecessor;
> + predecessor->commit_valid = true;
> + predecessor->tag_tid = position->tag_tid;
> + predecessor->entry_tid = position->entry_tid;
> + predecessor->uuid_len = 0;
> + predecessor->mirror_uuid = LOCAL_MIRROR_UUID;
> +
> + tag_data.uuid_len = 0;
> + tag_data.mirror_uuid = LOCAL_MIRROR_UUID;
If ->mirror_uuid is always "" (and ->uuid_len is always 0), drop them
and encode 0 directly instead of using ceph_encode_string().
Thanks,
Ilya
