backup: Switch block_backup.h to byte-based

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 <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Xie Changlong <xiechanglong@cmss.chinamobile.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block/backup.c b/block/backup.c
index 4e64710b39e3aeba58be7c92fa935d4cbd535d45..503fbec8c1d6d8927de81e8f19487869080f002e 100644 (file)
--- a/block/backup.c
+++ b/block/backup.c
@@ -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 && start < 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 start, int64_t end)
 {
-    req->start = start;
-    req->end = end;
+    req->start_byte = start;
+    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 3885f04c31ac6d6c9695a06a31339350b48067e8..8f3aba7a20f58a0392b3a29f5d69df223ed935a0 100644 (file)
--- 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);

diff --git a/include/block/block_backup.h b/include/block/block_backup.h
index 8a759477a3426b6fd741650c1fd4772226974806..994a3bd2ec8799c8defacb7e027e8a715532081c 100644 (file)
--- 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);