[Qemu-devel] [PATCH 12/12] block/backup: loosen restriction on readonly bitmaps

John Snow posted 12 patches 6 years, 4 months ago
Maintainers: Markus Armbruster <armbru@redhat.com>, Max Reitz <mreitz@redhat.com>, Wen Congyang <wencongyang2@huawei.com>, Fam Zheng <fam@euphon.net>, Xie Changlong <xiechanglong.d@gmail.com>, Eric Blake <eblake@redhat.com>, John Snow <jsnow@redhat.com>, Kevin Wolf <kwolf@redhat.com>
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[Qemu-devel] [PATCH 12/12] block/backup: loosen restriction on readonly bitmaps
Posted by John Snow 6 years, 4 months ago
With the "never" sync policy, we actually can utilize readonly bitmaps
now. Loosen the check at the QMP level, and tighten it based on
provided arguments down at the job creation level instead.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 block/backup.c | 6 ++++++
 blockdev.c     | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index beb2078696..ead9a049e2 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -614,6 +614,12 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
             return NULL;
         }
 
+        /* If we need to write to this bitmap, check that we can: */
+        if (bitmap_mode != BITMAP_SYNC_MODE_NEVER &&
+            bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp)) {
+            return NULL;
+        }
+
         /* Create a new bitmap, and freeze/disable this one. */
         if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) {
             return NULL;
diff --git a/blockdev.c b/blockdev.c
index 7abbd6bbf2..173a6b85c6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3560,7 +3560,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
             goto unref;
         }
-        if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) {
+        if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
             goto unref;
         }
     }
@@ -3667,7 +3667,7 @@ BlockJob *do_blockdev_backup(BlockdevBackup *backup, JobTxn *txn,
             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
             goto out;
         }
-        if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) {
+        if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
             goto out;
         }
     }
-- 
2.21.0


Re: [Qemu-devel] [PATCH 12/12] block/backup: loosen restriction on readonly bitmaps
Posted by Max Reitz 6 years, 4 months ago
On 20.06.19 03:03, John Snow wrote:
> With the "never" sync policy, we actually can utilize readonly bitmaps
> now. Loosen the check at the QMP level, and tighten it based on
> provided arguments down at the job creation level instead.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  block/backup.c | 6 ++++++
>  blockdev.c     | 4 ++--
>  2 files changed, 8 insertions(+), 2 deletions(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>