Block patches for 4.1.0-rc4:

- Fix the backup block job when using copy offloading
 - Fix the mirror block job when using the write-blocking copy mode
 - Fix incremental backups after the image has been grown with the
   respective bitmap attached to it
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Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-08-06' into staging

Block patches for 4.1.0-rc4:
- Fix the backup block job when using copy offloading
- Fix the mirror block job when using the write-blocking copy mode
- Fix incremental backups after the image has been grown with the
  respective bitmap attached to it

# gpg: Signature made Tue 06 Aug 2019 12:57:07 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-08-06:
  block/backup: disable copy_range for compressed backup
  iotests: Test unaligned blocking mirror write
  mirror: Only mirror granularity-aligned chunks
  iotests: Test incremental backup after truncation
  util/hbitmap: update orig_size on truncate
  iotests: Test backup job with two guest writes
  backup: Copy only dirty areas

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

block/backup.c

@@ -202,22 +202,31 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,
     cow_request_begin(&cow_request, job, start, end);
 
     while (start < end) {
+        int64_t dirty_end;
+
         if (!hbitmap_get(job->copy_bitmap, start)) {
             trace_backup_do_cow_skip(job, start);
             start += job->cluster_size;
             continue; /* already copied */
         }
 
+        dirty_end = hbitmap_next_zero(job->copy_bitmap, start, (end - start));
+        if (dirty_end < 0) {
+            dirty_end = end;
+        }
+
         trace_backup_do_cow_process(job, start);
 
         if (job->use_copy_range) {
-            ret = backup_cow_with_offload(job, start, end, is_write_notifier);
+            ret = backup_cow_with_offload(job, start, dirty_end,
+                                          is_write_notifier);
             if (ret < 0) {
                 job->use_copy_range = false;
             }
         }
         if (!job->use_copy_range) {
-            ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier,
+            ret = backup_cow_with_bounce_buffer(job, start, dirty_end,
+                                                is_write_notifier,
                                                 error_is_read, &bounce_buffer);
         }
         if (ret < 0) {
@@ -648,7 +657,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     job->cluster_size = cluster_size;
     job->copy_bitmap = copy_bitmap;
     copy_bitmap = NULL;
-    job->use_copy_range = true;
+    job->use_copy_range = !compress; /* compression isn't supported for it */
     job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
                                         blk_get_max_transfer(job->target));
     job->copy_range_size = MAX(job->cluster_size,

block/mirror.c

@@ -1481,6 +1481,15 @@ static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c,
     *nshared = BLK_PERM_ALL;
 }
 
+static void bdrv_mirror_top_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    MirrorBDSOpaque *s = bs->opaque;
+
+    if (s && s->job && s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING) {
+        bs->bl.request_alignment = s->job->granularity;
+    }
+}
+
 /* Dummy node that provides consistent read to its users without requiring it
  * from its backing file and that allows writes on the backing file chain. */
 static BlockDriver bdrv_mirror_top = {
@@ -1493,6 +1502,7 @@ static BlockDriver bdrv_mirror_top = {
     .bdrv_co_block_status       = bdrv_co_block_status_from_backing,
     .bdrv_refresh_filename      = bdrv_mirror_top_refresh_filename,
     .bdrv_child_perm            = bdrv_mirror_top_child_perm,
+    .bdrv_refresh_limits        = bdrv_mirror_top_refresh_limits,
 };
 
 static BlockJob *mirror_start_job(
@@ -1637,6 +1647,25 @@ static BlockJob *mirror_start_job(
         s->should_complete = true;
     }
 
+    /*
+     * Must be called before we start tracking writes, but after
+     *
+     *     ((MirrorBlockJob *)
+     *         ((MirrorBDSOpaque *)
+     *             mirror_top_bs->opaque
+     *         )->job
+     *     )->copy_mode
+     *
+     * has the correct value.
+     * (We start tracking writes as of the following
+     * bdrv_create_dirty_bitmap() call.)
+     */
+    bdrv_refresh_limits(mirror_top_bs, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        goto fail;
+    }
+
     s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
     if (!s->dirty_bitmap) {
         goto fail;

tests/qemu-iotests/056

@@ -133,6 +133,7 @@ class BackupTest(iotests.QMPTestCase):
         self.vm = iotests.VM()
         self.test_img = img_create('test')
         self.dest_img = img_create('dest')
+        self.ref_img = img_create('ref')
         self.vm.add_drive(self.test_img)
         self.vm.launch()
 
@@ -140,6 +141,7 @@ class BackupTest(iotests.QMPTestCase):
         self.vm.shutdown()
         try_remove(self.test_img)
         try_remove(self.dest_img)
+        try_remove(self.ref_img)
 
     def hmp_io_writes(self, drive, patterns):
         for pattern in patterns:
@@ -177,6 +179,43 @@ class BackupTest(iotests.QMPTestCase):
             self.assert_qmp(event, 'data/error', qerror)
             return False
 
+    def test_overlapping_writes(self):
+        # Write something to back up
+        self.hmp_io_writes('drive0', [('42', '0M', '2M')])
+
+        # Create a reference backup
+        self.qmp_backup_and_wait(device='drive0', format=iotests.imgfmt,
+                                 sync='full', target=self.ref_img,
+                                 auto_dismiss=False)
+        res = self.vm.qmp('block-job-dismiss', id='drive0')
+        self.assert_qmp(res, 'return', {})
+
+        # Now to the test backup: We simulate the following guest
+        # writes:
+        # (1) [1M + 64k, 1M + 128k): Afterwards, everything in that
+        #     area should be in the target image, and we must not copy
+        #     it again (because the source image has changed now)
+        #     (64k is the job's cluster size)
+        # (2) [1M, 2M): The backup job must not get overeager.  It
+        #     must copy [1M, 1M + 64k) and [1M + 128k, 2M) separately,
+        #     but not the area in between.
+
+        self.qmp_backup(device='drive0', format=iotests.imgfmt, sync='full',
+                        target=self.dest_img, speed=1, auto_dismiss=False)
+
+        self.hmp_io_writes('drive0', [('23', '%ik' % (1024 + 64), '64k'),
+                                      ('66', '1M', '1M')])
+
+        # Let the job complete
+        res = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
+        self.assert_qmp(res, 'return', {})
+        self.qmp_backup_wait('drive0')
+        res = self.vm.qmp('block-job-dismiss', id='drive0')
+        self.assert_qmp(res, 'return', {})
+
+        self.assertTrue(iotests.compare_images(self.ref_img, self.dest_img),
+                        'target image does not match reference image')
+
     def test_dismiss_false(self):
         res = self.vm.qmp('query-block-jobs')
         self.assert_qmp(res, 'return', [])

tests/qemu-iotests/056.out

@@ -1,5 +1,5 @@
-.........
+..........
 ----------------------------------------------------------------------
-Ran 9 tests
+Ran 10 tests
 
 OK

tests/qemu-iotests/124

@@ -212,25 +212,28 @@ class TestIncrementalBackupBase(iotests.QMPTestCase):
         return bitmap
 
 
-    def prepare_backup(self, bitmap=None, parent=None):
+    def prepare_backup(self, bitmap=None, parent=None, **kwargs):
         if bitmap is None:
             bitmap = self.bitmaps[-1]
         if parent is None:
             parent, _ = bitmap.last_target()
 
         target, _ = bitmap.new_target()
-        self.img_create(target, bitmap.drive['fmt'], parent=parent)
+        self.img_create(target, bitmap.drive['fmt'], parent=parent,
+                        **kwargs)
         return target
 
 
     def create_incremental(self, bitmap=None, parent=None,
-                           parentFormat=None, validate=True):
+                           parentFormat=None, validate=True,
+                           target=None):
         if bitmap is None:
             bitmap = self.bitmaps[-1]
         if parent is None:
             parent, _ = bitmap.last_target()
 
-        target = self.prepare_backup(bitmap, parent)
+        if target is None:
+            target = self.prepare_backup(bitmap, parent)
         res = self.do_qmp_backup(job_id=bitmap.drive['id'],
                                  device=bitmap.drive['id'],
                                  sync='incremental', bitmap=bitmap.name,
@@ -572,6 +575,33 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
                           'bitmap0', self.drives[0],
                           granularity=64000)
 
+    def test_growing_before_backup(self):
+        '''
+        Test: Add a bitmap, truncate the image, write past the old
+              end, do a backup.
+
+        Incremental backup should not ignore dirty bits past the old
+        image end.
+        '''
+        self.assert_no_active_block_jobs()
+
+        self.create_anchor_backup()
+
+        self.add_bitmap('bitmap0', self.drives[0])
+
+        res = self.vm.qmp('block_resize', device=self.drives[0]['id'],
+                          size=(65 * 1048576))
+        self.assert_qmp(res, 'return', {})
+
+        # Dirty the image past the old end
+        self.vm.hmp_qemu_io(self.drives[0]['id'], 'write 64M 64k')
+
+        target = self.prepare_backup(size='65M')
+        self.create_incremental(target=target)
+
+        self.vm.shutdown()
+        self.check_backups()
+
 
 class TestIncrementalBackupBlkdebug(TestIncrementalBackupBase):
     '''Incremental backup tests that utilize a BlkDebug filter on drive0.'''

tests/qemu-iotests/124.out

@@ -1,5 +1,5 @@
-............
+.............
 ----------------------------------------------------------------------
-Ran 12 tests
+Ran 13 tests
 
 OK

tests/qemu-iotests/151

@@ -114,6 +114,31 @@ class TestActiveMirror(iotests.QMPTestCase):
     def testActiveIOFlushed(self):
         self.doActiveIO(True)
 
+    def testUnalignedActiveIO(self):
+        # Fill the source image
+        result = self.vm.hmp_qemu_io('source', 'write -P 1 0 2M')
+
+        # Start the block job (very slowly)
+        result = self.vm.qmp('blockdev-mirror',
+                             job_id='mirror',
+                             filter_node_name='mirror-node',
+                             device='source-node',
+                             target='target-node',
+                             sync='full',
+                             copy_mode='write-blocking',
+                             buf_size=(1048576 // 4),
+                             speed=1)
+        self.assert_qmp(result, 'return', {})
+
+        # Start an unaligned request to a dirty area
+        result = self.vm.hmp_qemu_io('source', 'write -P 2 %i 1' % (1048576 + 42))
+
+        # Let the job finish
+        result = self.vm.qmp('block-job-set-speed', device='mirror', speed=0)
+        self.assert_qmp(result, 'return', {})
+        self.complete_and_wait(drive='mirror')
+
+        self.potential_writes_in_flight = False
 
 
 if __name__ == '__main__':

tests/qemu-iotests/151.out

@@ -1,5 +1,5 @@
-..
+...
 ----------------------------------------------------------------------
-Ran 2 tests
+Ran 3 tests
 
 OK

util/hbitmap.c

@@ -53,7 +53,9 @@
  */
 
 struct HBitmap {
-    /* Size of the bitmap, as requested in hbitmap_alloc. */
+    /*
+     * Size of the bitmap, as requested in hbitmap_alloc or in hbitmap_truncate.
+     */
     uint64_t orig_size;
 
     /* Number of total bits in the bottom level.  */
@@ -732,6 +734,8 @@ void hbitmap_truncate(HBitmap *hb, uint64_t size)
     uint64_t num_elements = size;
     uint64_t old;
 
+    hb->orig_size = size;
+
     /* Size comes in as logical elements, adjust for granularity. */
     size = (size + (1ULL << hb->granularity) - 1) >> hb->granularity;
     assert(size <= ((uint64_t)1 << HBITMAP_LOG_MAX_SIZE));