This patch completes the series with the COR-filter applied to
block-stream operations. Adding the filter makes it possible for copied
regions to be discarded in backing files during the block-stream job,
what will reduce the disk overuse.
The COR-filter insertion incurs changes in the test case
245:test_block_stream_4 that reopens the backing chain during a
block-stream job. There are changes in the test #030 as well.
The test case 030:test_stream_parallel was deleted due to multiple
conflicts between the concurrent job operations over the same backing
chain. All the nodes involved into one job are being frozen, including
the filter node. Operations over the mentioned nodes, including the
filter one, are being blocked for other jobs. So, the filter node gets
involved into two concurrent jobs with the adjacent data node. That is
not allowed. It is what the test cases with overlapping jobs are about.
The concept of the parallel jobs with common nodes is considered vital
no more.
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
block/stream.c | 97 ++++++++++++++++++++++++++++++----------------
tests/qemu-iotests/030 | 51 +++---------------------
tests/qemu-iotests/030.out | 4 +-
tests/qemu-iotests/141.out | 2 +-
tests/qemu-iotests/245 | 22 +++++++----
5 files changed, 86 insertions(+), 90 deletions(-)
diff --git a/block/stream.c b/block/stream.c
index 061268b..2f80fae 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -18,8 +18,10 @@
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
+#include "qapi/qmp/qdict.h"
#include "qemu/ratelimit.h"
#include "sysemu/block-backend.h"
+#include "block/copy-on-read.h"
enum {
/*
@@ -34,6 +36,8 @@ typedef struct StreamBlockJob {
BlockJob common;
BlockDriverState *base_overlay; /* COW overlay (stream from this) */
BlockDriverState *above_base; /* Node directly above the base */
+ BlockDriverState *cor_filter_bs;
+ BlockDriverState *target_bs;
BlockdevOnError on_error;
char *backing_file_str;
bool bs_read_only;
@@ -45,8 +49,7 @@ static int coroutine_fn stream_populate(BlockBackend *blk,
{
assert(bytes < SIZE_MAX);
- return blk_co_preadv(blk, offset, bytes, NULL,
- BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH);
+ return blk_co_preadv(blk, offset, bytes, NULL, BDRV_REQ_PREFETCH);
}
static void stream_abort(Job *job)
@@ -54,24 +57,21 @@ static void stream_abort(Job *job)
StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
if (s->chain_frozen) {
- BlockJob *bjob = &s->common;
- bdrv_unfreeze_backing_chain(blk_bs(bjob->blk), s->above_base);
+ bdrv_unfreeze_backing_chain(s->cor_filter_bs, s->above_base);
}
}
static int stream_prepare(Job *job)
{
StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
- BlockJob *bjob = &s->common;
- BlockDriverState *bs = blk_bs(bjob->blk);
- BlockDriverState *unfiltered_bs = bdrv_skip_filters(bs);
+ BlockDriverState *unfiltered_bs = bdrv_skip_filters(s->target_bs);
BlockDriverState *base = bdrv_filter_or_cow_bs(s->above_base);
BlockDriverState *base_unfiltered;
BlockDriverState *backing_bs;
Error *local_err = NULL;
int ret = 0;
- bdrv_unfreeze_backing_chain(bs, s->above_base);
+ bdrv_unfreeze_backing_chain(s->cor_filter_bs, s->above_base);
s->chain_frozen = false;
if (bdrv_cow_child(unfiltered_bs)) {
@@ -79,7 +79,7 @@ static int stream_prepare(Job *job)
if (base) {
base_id = s->backing_file_str;
if (base_id) {
- backing_bs = bdrv_find_backing_image(bs, base_id);
+ backing_bs = bdrv_find_backing_image(unfiltered_bs, base_id);
if (backing_bs && backing_bs->drv) {
base_fmt = backing_bs->drv->format_name;
} else {
@@ -111,15 +111,16 @@ static void stream_clean(Job *job)
{
StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
BlockJob *bjob = &s->common;
- BlockDriverState *bs = blk_bs(bjob->blk);
/* Reopen the image back in read-only mode if necessary */
if (s->bs_read_only) {
/* Give up write permissions before making it read-only */
blk_set_perm(bjob->blk, 0, BLK_PERM_ALL, &error_abort);
- bdrv_reopen_set_read_only(bs, true, NULL);
+ bdrv_reopen_set_read_only(s->target_bs, true, NULL);
}
+ bdrv_cor_filter_drop(s->cor_filter_bs);
+
g_free(s->backing_file_str);
}
@@ -127,9 +128,7 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
{
StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
BlockBackend *blk = s->common.blk;
- BlockDriverState *bs = blk_bs(blk);
- BlockDriverState *unfiltered_bs = bdrv_skip_filters(bs);
- bool enable_cor = !bdrv_cow_child(s->base_overlay);
+ BlockDriverState *unfiltered_bs = bdrv_skip_filters(s->target_bs);
int64_t len;
int64_t offset = 0;
uint64_t delay_ns = 0;
@@ -141,21 +140,12 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
return 0;
}
- len = bdrv_getlength(bs);
+ len = bdrv_getlength(s->target_bs);
if (len < 0) {
return len;
}
job_progress_set_remaining(&s->common.job, len);
- /* Turn on copy-on-read for the whole block device so that guest read
- * requests help us make progress. Only do this when copying the entire
- * backing chain since the copy-on-read operation does not take base into
- * account.
- */
- if (enable_cor) {
- bdrv_enable_copy_on_read(bs);
- }
-
for ( ; offset < len; offset += n) {
bool copy;
int ret;
@@ -214,10 +204,6 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
}
}
- if (enable_cor) {
- bdrv_disable_copy_on_read(bs);
- }
-
/* Do not remove the backing file if an error was there but ignored. */
return error;
}
@@ -247,7 +233,9 @@ void stream_start(const char *job_id, BlockDriverState *bs,
bool bs_read_only;
int basic_flags = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED;
BlockDriverState *base_overlay = bdrv_find_overlay(bs, base);
+ BlockDriverState *cor_filter_bs = NULL;
BlockDriverState *above_base;
+ QDict *opts;
if (!base_overlay) {
error_setg(errp, "'%s' is not in the backing chain of '%s'",
@@ -281,17 +269,51 @@ void stream_start(const char *job_id, BlockDriverState
*bs,
}
}
- /* Prevent concurrent jobs trying to modify the graph structure here, we
- * already have our own plans. Also don't allow resize as the image size is
- * queried only at the job start and then cached. */
- s = block_job_create(job_id, &stream_job_driver, NULL, bs,
- basic_flags | BLK_PERM_GRAPH_MOD,
+ opts = qdict_new();
+
+ qdict_put_str(opts, "driver", "copy-on-read");
+ qdict_put_str(opts, "file", bdrv_get_node_name(bs));
+ if (base) {
+ /* Pass the base_overlay node name as 'bottom' to COR driver */
+ qdict_put_str(opts, "bottom", base_overlay->node_name);
+ }
+ if (filter_node_name) {
+ qdict_put_str(opts, "node-name", filter_node_name);
+ }
+
+ cor_filter_bs = bdrv_insert_node(bs, opts, BDRV_O_RDWR, errp);
+ if (cor_filter_bs == NULL) {
+ goto fail;
+ }
+
+ if (!filter_node_name) {
+ cor_filter_bs->implicit = true;
+ }
+
+ if (bdrv_freeze_backing_chain(cor_filter_bs, bs, errp) < 0) {
+ bdrv_cor_filter_drop(cor_filter_bs);
+ cor_filter_bs = NULL;
+ goto fail;
+ }
+
+ s = block_job_create(job_id, &stream_job_driver, NULL, cor_filter_bs,
+ BLK_PERM_CONSISTENT_READ,
basic_flags | BLK_PERM_WRITE,
speed, creation_flags, NULL, NULL, errp);
if (!s) {
goto fail;
}
+ /*
+ * Prevent concurrent jobs trying to modify the graph structure here, we
+ * already have our own plans. Also don't allow resize as the image size is
+ * queried only at the job start and then cached.
+ */
+ if (block_job_add_bdrv(&s->common, "active node", bs, 0,
+ basic_flags | BLK_PERM_WRITE, &error_abort)) {
+ goto fail;
+ }
+
/* Block all intermediate nodes between bs and base, because they will
* disappear from the chain after this operation. The streaming job reads
* every block only once, assuming that it doesn't change, so forbid writes
@@ -312,6 +334,8 @@ void stream_start(const char *job_id, BlockDriverState *bs,
s->base_overlay = base_overlay;
s->above_base = above_base;
s->backing_file_str = g_strdup(backing_file_str);
+ s->cor_filter_bs = cor_filter_bs;
+ s->target_bs = bs;
s->bs_read_only = bs_read_only;
s->chain_frozen = true;
@@ -324,5 +348,10 @@ fail:
if (bs_read_only) {
bdrv_reopen_set_read_only(bs, true, NULL);
}
- bdrv_unfreeze_backing_chain(bs, above_base);
+ if (cor_filter_bs) {
+ bdrv_unfreeze_backing_chain(cor_filter_bs, above_base);
+ bdrv_cor_filter_drop(cor_filter_bs);
+ } else {
+ bdrv_unfreeze_backing_chain(bs, above_base);
+ }
}
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index dcb4b5d..0064590 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -227,61 +227,20 @@ class TestParallelOps(iotests.QMPTestCase):
for img in self.imgs:
os.remove(img)
- # Test that it's possible to run several block-stream operations
- # in parallel in the same snapshot chain
- @unittest.skipIf(os.environ.get('QEMU_CHECK_BLOCK_AUTO'), 'disabled in CI')
- def test_stream_parallel(self):
- self.assert_no_active_block_jobs()
-
- # Check that the maps don't match before the streaming operations
- for i in range(2, self.num_imgs, 2):
- self.assertNotEqual(qemu_io('-f', iotests.imgfmt, '-rU', '-c',
'map', self.imgs[i]),
- qemu_io('-f', iotests.imgfmt, '-rU', '-c',
'map', self.imgs[i-1]),
- 'image file map matches backing file before
streaming')
-
- # Create all streaming jobs
- pending_jobs = []
- for i in range(2, self.num_imgs, 2):
- node_name = 'node%d' % i
- job_id = 'stream-%s' % node_name
- pending_jobs.append(job_id)
- result = self.vm.qmp('block-stream', device=node_name,
job_id=job_id, base=self.imgs[i-2], speed=1024)
- self.assert_qmp(result, 'return', {})
-
- for job in pending_jobs:
- result = self.vm.qmp('block-job-set-speed', device=job, speed=0)
- self.assert_qmp(result, 'return', {})
-
- # Wait for all jobs to be finished.
- while len(pending_jobs) > 0:
- for event in self.vm.get_qmp_events(wait=True):
- if event['event'] == 'BLOCK_JOB_COMPLETED':
- job_id = self.dictpath(event, 'data/device')
- self.assertTrue(job_id in pending_jobs)
- self.assert_qmp_absent(event, 'data/error')
- pending_jobs.remove(job_id)
-
- self.assert_no_active_block_jobs()
- self.vm.shutdown()
-
- # Check that all maps match now
- for i in range(2, self.num_imgs, 2):
- self.assertEqual(qemu_io('-f', iotests.imgfmt, '-c', 'map',
self.imgs[i]),
- qemu_io('-f', iotests.imgfmt, '-c', 'map',
self.imgs[i-1]),
- 'image file map does not match backing file after
streaming')
-
# Test that it's not possible to perform two block-stream
# operations if there are nodes involved in both.
def test_overlapping_1(self):
self.assert_no_active_block_jobs()
# Set a speed limit to make sure that this job blocks the rest
- result = self.vm.qmp('block-stream', device='node4',
job_id='stream-node4', base=self.imgs[1], speed=1024*1024)
+ result = self.vm.qmp('block-stream', device='node4',
+ job_id='stream-node4', base=self.imgs[1],
+ filter_node_name='stream-filter', speed=1024*1024)
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('block-stream', device='node5',
job_id='stream-node5', base=self.imgs[2])
self.assert_qmp(result, 'error/desc',
- "Node 'node4' is busy: block device is in use by block job:
stream")
+ "Node 'stream-filter' is busy: block device is in use by block
job: stream")
result = self.vm.qmp('block-stream', device='node3',
job_id='stream-node3', base=self.imgs[2])
self.assert_qmp(result, 'error/desc',
@@ -294,7 +253,7 @@ class TestParallelOps(iotests.QMPTestCase):
# block-commit should also fail if it touches nodes used by the stream
job
result = self.vm.qmp('block-commit', device='drive0',
base=self.imgs[4], job_id='commit-node4')
self.assert_qmp(result, 'error/desc',
- "Node 'node4' is busy: block device is in use by block job:
stream")
+ "Node 'stream-filter' is busy: block device is in use by block
job: stream")
result = self.vm.qmp('block-commit', device='drive0',
base=self.imgs[1], top=self.imgs[3], job_id='commit-node1')
self.assert_qmp(result, 'error/desc',
diff --git a/tests/qemu-iotests/030.out b/tests/qemu-iotests/030.out
index 6d9bee1..5eb508d 100644
--- a/tests/qemu-iotests/030.out
+++ b/tests/qemu-iotests/030.out
@@ -1,5 +1,5 @@
-...........................
+..........................
----------------------------------------------------------------------
-Ran 27 tests
+Ran 26 tests
OK
diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index 08e0aec..028a16f 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -99,7 +99,7 @@ wrote 1048576/1048576 bytes at offset 0
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event":
"JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event":
"JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
{'execute': 'blockdev-del', 'arguments': {'node-name': 'drv0'}}
-{"error": {"class": "GenericError", "desc": "Node drv0 is in use"}}
+{"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device
is in use by block job: stream"}}
{'execute': 'block-job-cancel', 'arguments': {'device': 'job0'}}
{"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event":
"JOB_STATUS_CHANGE", "data": {"status": "aborting", "id": "job0"}}
diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
index e60c832..af3273a 100755
--- a/tests/qemu-iotests/245
+++ b/tests/qemu-iotests/245
@@ -899,17 +899,25 @@ class TestBlockdevReopen(iotests.QMPTestCase):
# make hd1 read-only and block-stream requires it to be read-write
# (Which error message appears depends on whether the stream job is
# already done with copying at this point.)
- self.reopen(opts, {},
- ["Can't set node 'hd1' to r/o with copy-on-read enabled",
- "Cannot make block node read-only, there is a writer on it"])
+ # As the COR-filter node is inserted into the backing chain with the
+ # 'block-stream' operation, we move the options to their proper nodes.
+ opts = hd_opts(1)
+ opts['backing'] = hd_opts(2)
+ opts['backing']['backing'] = None
+ self.reopen(opts, {'read-only': True},
+ ["Cannot make block node read-only, there is a writer on it"])
# We can't remove hd2 while the stream job is ongoing
- opts['backing']['backing'] = None
- self.reopen(opts, {'backing.read-only': False}, "Cannot change
'backing' link from 'hd1' to 'hd2'")
+ opts['backing'] = None
+ self.reopen(opts, {'read-only': False},
+ "Cannot change 'backing' link from 'hd1' to 'hd2'")
- # We can detach hd1 from hd0 because it doesn't affect the stream job
+ # We can't detach hd1 from hd0 because there is the COR-filter implicit
+ # node in between.
+ opts = hd_opts(0)
opts['backing'] = None
- self.reopen(opts)
+ self.reopen(opts, {},
+ "Cannot change backing link if 'hd0' has an implicit
backing file")
self.vm.run_job('stream0', auto_finalize = False, auto_dismiss = True)
--
1.8.3.1
