On Tue, Jun 27, 2017 at 02:24:53PM -0500, Eric Blake wrote:
> We are gradually converting to byte-based interfaces, as they are
> easier to reason about than sector-based. Continue by converting
> the public interface to backup jobs (no semantic change), including
> a change to CowRequest to track by bytes instead of cluster indices.
>
> Note that this does not change the difference between the public
> interface (starting point, and size of the subsequent range) and
> the internal interface (starting and end points).
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> Reviewed-by: John Snow <js...@redhat.com>
>
Reviewed-by: Jeff Cody <jc...@redhat.com>
> ---
> v2: change a couple more parameter names
> ---
> include/block/block_backup.h | 11 +++++------
> block/backup.c | 33 ++++++++++++++++-----------------
> block/replication.c | 12 ++++++++----
> 3 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/include/block/block_backup.h b/include/block/block_backup.h
> index 8a75947..994a3bd 100644
> --- a/include/block/block_backup.h
> +++ b/include/block/block_backup.h
> @@ -21,17 +21,16 @@
> #include "block/block_int.h"
>
> typedef struct CowRequest {
> - int64_t start;
> - int64_t end;
> + int64_t start_byte;
> + int64_t end_byte;
> QLIST_ENTRY(CowRequest) list;
> CoQueue wait_queue; /* coroutines blocked on this request */
> } CowRequest;
>
> -void backup_wait_for_overlapping_requests(BlockJob *job, int64_t sector_num,
> - int nb_sectors);
> +void backup_wait_for_overlapping_requests(BlockJob *job, int64_t offset,
> + uint64_t bytes);
> void backup_cow_request_begin(CowRequest *req, BlockJob *job,
> - int64_t sector_num,
> - int nb_sectors);
> + int64_t offset, uint64_t bytes);
> void backup_cow_request_end(CowRequest *req);
>
> void backup_do_checkpoint(BlockJob *job, Error **errp);
> diff --git a/block/backup.c b/block/backup.c
> index 4e64710..cfbd921 100644
> --- a/block/backup.c
> +++ b/block/backup.c
> @@ -55,7 +55,7 @@ static inline int64_t cluster_size_sectors(BackupBlockJob
> *job)
>
> /* See if in-flight requests overlap and wait for them to complete */
> static void coroutine_fn wait_for_overlapping_requests(BackupBlockJob *job,
> - int64_t start,
> + int64_t offset,
> int64_t end)
> {
> CowRequest *req;
> @@ -64,7 +64,7 @@ static void coroutine_fn
> wait_for_overlapping_requests(BackupBlockJob *job,
> do {
> retry = false;
> QLIST_FOREACH(req, &job->inflight_reqs, list) {
> - if (end > req->start && start < req->end) {
> + if (end > req->start_byte && offset < req->end_byte) {
> qemu_co_queue_wait(&req->wait_queue, NULL);
> retry = true;
> break;
> @@ -75,10 +75,10 @@ static void coroutine_fn
> wait_for_overlapping_requests(BackupBlockJob *job,
>
> /* Keep track of an in-flight request */
> static void cow_request_begin(CowRequest *req, BackupBlockJob *job,
> - int64_t start, int64_t end)
> + int64_t offset, int64_t end)
> {
> - req->start = start;
> - req->end = end;
> + req->start_byte = offset;
> + req->end_byte = end;
> qemu_co_queue_init(&req->wait_queue);
> QLIST_INSERT_HEAD(&job->inflight_reqs, req, list);
> }
> @@ -114,8 +114,10 @@ static int coroutine_fn backup_do_cow(BackupBlockJob
> *job,
> sector_num * BDRV_SECTOR_SIZE,
> nb_sectors * BDRV_SECTOR_SIZE);
>
> - wait_for_overlapping_requests(job, start, end);
> - cow_request_begin(&cow_request, job, start, end);
> + wait_for_overlapping_requests(job, start * job->cluster_size,
> + end * job->cluster_size);
> + cow_request_begin(&cow_request, job, start * job->cluster_size,
> + end * job->cluster_size);
>
> for (; start < end; start++) {
> if (test_bit(start, job->done_bitmap)) {
> @@ -277,32 +279,29 @@ void backup_do_checkpoint(BlockJob *job, Error **errp)
> bitmap_zero(backup_job->done_bitmap, len);
> }
>
> -void backup_wait_for_overlapping_requests(BlockJob *job, int64_t sector_num,
> - int nb_sectors)
> +void backup_wait_for_overlapping_requests(BlockJob *job, int64_t offset,
> + uint64_t bytes)
> {
> BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
> - int64_t sectors_per_cluster = cluster_size_sectors(backup_job);
> int64_t start, end;
>
> assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
>
> - start = sector_num / sectors_per_cluster;
> - end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
> + start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
> + end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
> wait_for_overlapping_requests(backup_job, start, end);
> }
>
> void backup_cow_request_begin(CowRequest *req, BlockJob *job,
> - int64_t sector_num,
> - int nb_sectors)
> + int64_t offset, uint64_t bytes)
> {
> BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
> - int64_t sectors_per_cluster = cluster_size_sectors(backup_job);
> int64_t start, end;
>
> assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
>
> - start = sector_num / sectors_per_cluster;
> - end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
> + start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
> + end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
> cow_request_begin(req, backup_job, start, end);
> }
>
> diff --git a/block/replication.c b/block/replication.c
> index 3885f04..8f3aba7 100644
> --- a/block/replication.c
> +++ b/block/replication.c
> @@ -234,10 +234,14 @@ static coroutine_fn int
> replication_co_readv(BlockDriverState *bs,
> }
>
> if (job) {
> - backup_wait_for_overlapping_requests(child->bs->job, sector_num,
> - remaining_sectors);
> - backup_cow_request_begin(&req, child->bs->job, sector_num,
> - remaining_sectors);
> + uint64_t remaining_bytes = remaining_sectors * BDRV_SECTOR_SIZE;
> +
> + backup_wait_for_overlapping_requests(child->bs->job,
> + sector_num * BDRV_SECTOR_SIZE,
> + remaining_bytes);
> + backup_cow_request_begin(&req, child->bs->job,
> + sector_num * BDRV_SECTOR_SIZE,
> + remaining_bytes);
> ret = bdrv_co_readv(bs->file, sector_num, remaining_sectors,
> qiov);
> backup_cow_request_end(&req);
> --
> 2.9.4
>
