[Qemu-devel] [PATCH v8 0/4] block: ignore flush requests when storage is clean

[Qemu-devel] [PATCH v8 0/4] block: ignore flush requests when storage is clean

[Denis V. Lunev]

Changes from v7:
- fixed 026 test in cached mode (different output)

Changes from v6:
- squashed patches 5-6 into patch 4 to avoid test faults on git bissect
- changed sector number from 0 to 1 in patch 3

Changes from v5:
- Removed failed flush traces in block tests 026 071 089
- Changed BLOCK_JOB_READY event order in block tests 141 144

Changes from v4:
- Moved to write generation scheme instead of dirty flag
- Added retry setup to IDE PIO and FLUSH requests

Changes from v3:
- Fixed a typo in commit message
- Rebased on Kevin'n origin/block

Changes from v2:
- Better comments
- Rebased on latest master

Changes from v1:
- Flush requests that should be skipped will now wait for completion
  of any previous requests already in flight
- Fixed IDE and AHCI tests to dirty media for new flush behaviour
- Fixed a problem in IDE CMD_FLUSH_CACHE failure handling

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>

Evgeny Yakovlev (4):
  ide: refactor retry_unit set and clear into separate function
  ide: set retry_unit for PIO and FLUSH requests
  tests: in IDE and AHCI tests perform DMA write before flushing
  block: ignore flush requests when storage is clean

 block.c                            |  3 +++
 block/io.c                         | 21 ++++++++++++++++
 hw/ide/core.c                      | 24 +++++++++++++-----
 include/block/block_int.h          |  5 ++++
 tests/ahci-test.c                  | 34 ++++++++++++++++++++++++--
 tests/ide-test.c                   | 43 ++++++++++++++++++++++++++++++++
 tests/qemu-iotests/026.out         | 50 --------------------------------------
 tests/qemu-iotests/026.out.nocache | 50 --------------------------------------
 tests/qemu-iotests/071.out         |  8 ------
 tests/qemu-iotests/089.out         |  2 --
 tests/qemu-iotests/141.out         |  4 +--
 tests/qemu-iotests/144.out         |  2 +-
 12 files changed, 125 insertions(+), 121 deletions(-)

-- 
2.1.4

[Qemu-devel] [PATCH v8 1/4] ide: refactor retry_unit set and clear into separate function

[Denis V. Lunev]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

Code to set and clear state associated with retry in moved into
ide_set_retry and ide_clear_retry to make adding retry setups easier.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
---
 hw/ide/core.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index f2d131b..b8015d7 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -466,6 +466,20 @@ void ide_abort_command(IDEState *s)
     s->error = ABRT_ERR;
 }
 
+static void ide_set_retry(IDEState *s)
+{
+    s->bus->retry_unit = s->unit;
+    s->bus->retry_sector_num = ide_get_sector(s);
+    s->bus->retry_nsector = s->nsector;
+}
+
+static void ide_clear_retry(IDEState *s)
+{
+    s->bus->retry_unit = -1;
+    s->bus->retry_sector_num = 0;
+    s->bus->retry_nsector = 0;
+}
+
 /* prepare data transfer and tell what to do after */
 void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
                         EndTransferFunc *end_transfer_func)
@@ -756,9 +770,7 @@ void dma_buf_commit(IDEState *s, uint32_t tx_bytes)
 void ide_set_inactive(IDEState *s, bool more)
 {
     s->bus->dma->aiocb = NULL;
-    s->bus->retry_unit = -1;
-    s->bus->retry_sector_num = 0;
-    s->bus->retry_nsector = 0;
+    ide_clear_retry(s);
     if (s->bus->dma->ops->set_inactive) {
         s->bus->dma->ops->set_inactive(s->bus->dma, more);
     }
@@ -914,9 +926,7 @@ static void ide_sector_start_dma(IDEState *s, enum ide_dma_cmd dma_cmd)
 void ide_start_dma(IDEState *s, BlockCompletionFunc *cb)
 {
     s->io_buffer_index = 0;
-    s->bus->retry_unit = s->unit;
-    s->bus->retry_sector_num = ide_get_sector(s);
-    s->bus->retry_nsector = s->nsector;
+    ide_set_retry(s);
     if (s->bus->dma->ops->start_dma) {
         s->bus->dma->ops->start_dma(s->bus->dma, s, cb);
     }
-- 
2.1.4

[Qemu-devel] [PATCH v8 2/4] ide: set retry_unit for PIO and FLUSH requests

[Denis V. Lunev]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

The following sequence of tests discovered a problem in IDE emulation:
1. Send DMA write to IDE device 0
2. Send CMD_FLUSH_CACHE to same IDE device which will be failed by block
layer using blkdebug script in tests/ide-test:test_retry_flush

When doing DMA request ide/core.c will set s->retry_unit to s->unit in
ide_start_dma. When dma completes ide_set_inactive sets retry_unit to -1.
After that ide_flush_cache runs and fails thanks to blkdebug.
ide_flush_cb calls ide_handle_rw_error which asserts that s->retry_unit
== s->unit. But s->retry_unit is still -1 after previous DMA completion
and flush does not use anything related to retry.

This patch restricts retry unit assertion only to ops that actually use
retry logic.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
---
 hw/ide/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index b8015d7..b1daf96 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -487,6 +487,7 @@ void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
     s->end_transfer_func = end_transfer_func;
     s->data_ptr = buf;
     s->data_end = buf + size;
+    ide_set_retry(s);
     if (!(s->status & ERR_STAT)) {
         s->status |= DRQ_STAT;
     }
@@ -1056,6 +1057,7 @@ static void ide_flush_cache(IDEState *s)
     }
 
     s->status |= BUSY_STAT;
+    ide_set_retry(s);
     block_acct_start(blk_get_stats(s->blk), &s->acct, 0, BLOCK_ACCT_FLUSH);
     s->pio_aiocb = blk_aio_flush(s->blk, ide_flush_cb, s);
 }
-- 
2.1.4

[Qemu-devel] [PATCH v8 3/4] tests: in IDE and AHCI tests perform DMA write before flushing

[Denis V. Lunev]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

Due to changes in flush behaviour clean disks stopped generating
flush_to_disk events and IDE and AHCI tests that test flush commands
started to fail.

This change adds additional DMA writes to affected tests before sending
flush commands so that bdrv_flush actually generates flush_to_disk event.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
---
 tests/ahci-test.c | 34 ++++++++++++++++++++++++++++++++--
 tests/ide-test.c  | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/tests/ahci-test.c b/tests/ahci-test.c
index 57dc44c..9c0adce 100644
--- a/tests/ahci-test.c
+++ b/tests/ahci-test.c
@@ -1063,11 +1063,34 @@ static void test_dma_fragmented(void)
     g_free(tx);
 }
 
+/*
+ * Write sector 1 with random data to make AHCI storage dirty
+ * Needed for flush tests so that flushes actually go though the block layer
+ */
+static void make_dirty(AHCIQState* ahci, uint8_t port)
+{
+    uint64_t ptr;
+    unsigned bufsize = 512;
+
+    ptr = ahci_alloc(ahci, bufsize);
+    g_assert(ptr);
+
+    ahci_guest_io(ahci, port, CMD_WRITE_DMA, ptr, bufsize, 1);
+    ahci_free(ahci, ptr);
+}
+
 static void test_flush(void)
 {
     AHCIQState *ahci;
+    uint8_t port;
 
     ahci = ahci_boot_and_enable(NULL);
+
+    port = ahci_port_select(ahci);
+    ahci_port_clear(ahci, port);
+
+    make_dirty(ahci, port);
+
     ahci_test_flush(ahci);
     ahci_shutdown(ahci);
 }
@@ -1087,10 +1110,13 @@ static void test_flush_retry(void)
                                 debug_path,
                                 tmp_path, imgfmt);
 
-    /* Issue Flush Command and wait for error */
     port = ahci_port_select(ahci);
     ahci_port_clear(ahci, port);
 
+    /* Issue write so that flush actually goes to disk */
+    make_dirty(ahci, port);
+
+    /* Issue Flush Command and wait for error */
     cmd = ahci_guest_io_halt(ahci, port, CMD_FLUSH_CACHE, 0, 0, 0);
     ahci_guest_io_resume(ahci, cmd);
 
@@ -1343,9 +1369,13 @@ static void test_flush_migrate(void)
 
     set_context(src->parent);
 
-    /* Issue Flush Command */
     px = ahci_port_select(src);
     ahci_port_clear(src, px);
+
+    /* Dirty device so that flush reaches disk */
+    make_dirty(src, px);
+
+    /* Issue Flush Command */
     cmd = ahci_command_create(CMD_FLUSH_CACHE);
     ahci_command_commit(src, cmd, px);
     ahci_command_issue_async(src, cmd);
diff --git a/tests/ide-test.c b/tests/ide-test.c
index fed1b2e..1e51af2 100644
--- a/tests/ide-test.c
+++ b/tests/ide-test.c
@@ -499,6 +499,39 @@ static void test_identify(void)
     ide_test_quit();
 }
 
+/*
+ * Write sector 1 with random data to make IDE storage dirty
+ * Needed for flush tests so that flushes actually go though the block layer
+ */
+static void make_dirty(uint8_t device)
+{
+    uint8_t status;
+    size_t len = 512;
+    uintptr_t guest_buf;
+    void* buf;
+
+    guest_buf = guest_alloc(guest_malloc, len);
+    buf = g_malloc(len);
+    g_assert(guest_buf);
+    g_assert(buf);
+
+    memwrite(guest_buf, buf, len);
+
+    PrdtEntry prdt[] = {
+        {
+            .addr = cpu_to_le32(guest_buf),
+            .size = cpu_to_le32(len | PRDT_EOT),
+        },
+    };
+
+    status = send_dma_request(CMD_WRITE_DMA, 1, 1, prdt,
+                              ARRAY_SIZE(prdt), NULL);
+    g_assert_cmphex(status, ==, BM_STS_INTR);
+    assert_bit_clear(inb(IDE_BASE + reg_status), DF | ERR);
+
+    g_free(buf);
+}
+
 static void test_flush(void)
 {
     uint8_t data;
@@ -507,6 +540,11 @@ static void test_flush(void)
         "-drive file=blkdebug::%s,if=ide,cache=writeback,format=raw",
         tmp_path);
 
+    qtest_irq_intercept_in(global_qtest, "ioapic");
+
+    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
+    make_dirty(0);
+
     /* Delay the completion of the flush request until we explicitly do it */
     g_free(hmp("qemu-io ide0-hd0 \"break flush_to_os A\""));
 
@@ -549,6 +587,11 @@ static void test_retry_flush(const char *machine)
         "rerror=stop,werror=stop",
         debug_path, tmp_path);
 
+    qtest_irq_intercept_in(global_qtest, "ioapic");
+
+    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
+    make_dirty(0);
+
     /* FLUSH CACHE command on device 0*/
     outb(IDE_BASE + reg_device, 0);
     outb(IDE_BASE + reg_command, CMD_FLUSH_CACHE);
-- 
2.1.4

[Qemu-devel] [PATCH v8 4/4] block: ignore flush requests when storage is clean

[Denis V. Lunev]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

Some guests (win2008 server for example) do a lot of unnecessary
flushing when underlying media has not changed. This adds additional
overhead on host when calling fsync/fdatasync.

This change introduces a write generation scheme in BlockDriverState.
Current write generation is checked against last flushed generation to
avoid unnessesary flushes.

The problem with excessive flushing was found by a performance test
which does parallel directory tree creation (from 2 processes).
Results improved from 0.424 loops/sec to 0.432 loops/sec.
Each loop creates 10^3 directories with 10 files in each.

This affected some blkdebug testcases that were expecting error logs from
failure-injected flushes which are now skipped entirely
(tests 026 071 089).

This also affects the performance of block jobs and thus BLOCK_JOB_READY
events for driver-mirror and active block-commit commands now arrives
faster, before QMP send successfully returns to caller (tests 141 144).

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
---
 block.c                            |  3 +++
 block/io.c                         | 21 ++++++++++++++++
 include/block/block_int.h          |  5 ++++
 tests/qemu-iotests/026.out         | 50 --------------------------------------
 tests/qemu-iotests/026.out.nocache | 50 --------------------------------------
 tests/qemu-iotests/071.out         |  8 ------
 tests/qemu-iotests/089.out         |  2 --
 tests/qemu-iotests/141.out         |  4 +--
 tests/qemu-iotests/144.out         |  2 +-
 9 files changed, 32 insertions(+), 113 deletions(-)

diff --git a/block.c b/block.c
index 67894e0..d2dac3d 100644
--- a/block.c
+++ b/block.c
@@ -234,6 +234,8 @@ BlockDriverState *bdrv_new(void)
     bs->refcnt = 1;
     bs->aio_context = qemu_get_aio_context();
 
+    qemu_co_queue_init(&bs->flush_queue);
+
     QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
 
     return bs;
@@ -2472,6 +2474,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
         bdrv_dirty_bitmap_truncate(bs);
         bdrv_parent_cb_resize(bs);
+        ++bs->write_gen;
     }
     return ret;
 }
diff --git a/block/io.c b/block/io.c
index 2887394..cfda714 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1303,6 +1303,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
     }
     bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
 
+    ++bs->write_gen;
     bdrv_set_dirty(bs, start_sector, end_sector - start_sector);
 
     if (bs->wr_highest_offset < offset + bytes) {
@@ -2236,6 +2237,15 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
 
     tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH);
 
+    int current_gen = bs->write_gen;
+
+    /* Wait until any previous flushes are completed */
+    while (bs->flush_started_gen != bs->flushed_gen) {
+        qemu_co_queue_wait(&bs->flush_queue);
+    }
+
+    bs->flush_started_gen = current_gen;
+
     /* Write back all layers by calling one driver function */
     if (bs->drv->bdrv_co_flush) {
         ret = bs->drv->bdrv_co_flush(bs);
@@ -2256,6 +2266,11 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
         goto flush_parent;
     }
 
+    /* Check if we really need to flush anything */
+    if (bs->flushed_gen == current_gen) {
+        goto flush_parent;
+    }
+
     BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
     if (bs->drv->bdrv_co_flush_to_disk) {
         ret = bs->drv->bdrv_co_flush_to_disk(bs);
@@ -2286,6 +2301,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
          */
         ret = 0;
     }
+
     if (ret < 0) {
         goto out;
     }
@@ -2296,6 +2312,10 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
 flush_parent:
     ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0;
 out:
+    /* Notify any pending flushes that we have completed */
+    bs->flushed_gen = current_gen;
+    qemu_co_queue_restart_all(&bs->flush_queue);
+
     tracked_request_end(&req);
     return ret;
 }
@@ -2421,6 +2441,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
     }
     ret = 0;
 out:
+    ++bs->write_gen;
     bdrv_set_dirty(bs, req.offset >> BDRV_SECTOR_BITS,
                    req.bytes >> BDRV_SECTOR_BITS);
     tracked_request_end(&req);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8054146..a6b13ad 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -439,6 +439,11 @@ struct BlockDriverState {
     int copy_on_read; /* if nonzero, copy read backing sectors into image.
                          note this is a reference count */
 
+    CoQueue flush_queue;            /* Serializing flush queue */
+    unsigned int write_gen;         /* Current data generation */
+    unsigned int flush_started_gen; /* Generation for which flush has started */
+    unsigned int flushed_gen;       /* Flushed write generation */
+
     BlockDriver *drv; /* NULL means no media */
     void *opaque;
 
diff --git a/tests/qemu-iotests/026.out b/tests/qemu-iotests/026.out
index d84d82c..8531735 100644
--- a/tests/qemu-iotests/026.out
+++ b/tests/qemu-iotests/026.out
@@ -14,7 +14,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
@@ -23,7 +22,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
@@ -42,7 +40,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -51,7 +48,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -78,11 +74,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 5; imm: off; once: off; write
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -90,11 +82,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 5; imm: off; once: off; write -b
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -118,11 +106,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 28; imm: off; once: off; write
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -130,11 +114,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 28; imm: off; once: off; write -b
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -306,14 +286,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -330,14 +308,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -354,14 +330,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -378,14 +352,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -402,14 +374,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -426,14 +396,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -450,15 +418,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: cluster_alloc; errno: 5; imm: off; once: off; write
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: cluster_alloc; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -474,15 +438,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: cluster_alloc; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: cluster_alloc; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 
@@ -553,7 +513,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -562,7 +521,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -581,7 +539,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -590,7 +547,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -635,8 +591,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_alloc_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -647,8 +601,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_alloc_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -659,7 +611,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -671,7 +622,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
diff --git a/tests/qemu-iotests/026.out.nocache b/tests/qemu-iotests/026.out.nocache
index 9c2c8a9..672d77c 100644
--- a/tests/qemu-iotests/026.out.nocache
+++ b/tests/qemu-iotests/026.out.nocache
@@ -14,7 +14,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_update; errno: 5; imm: off; once: off; write 
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
@@ -23,7 +22,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_update; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 
@@ -42,7 +40,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_update; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -51,7 +48,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_update; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -78,11 +74,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 5; imm: off; once: off; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -90,11 +82,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 5; imm: off; once: off; write -b
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -118,11 +106,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 28; imm: off; once: off; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -130,11 +114,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Event: l2_load; errno: 28; imm: off; once: off; write -b
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -314,14 +294,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_load; errno: 5; imm: off; once: off; write 
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_load; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -338,14 +316,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_load; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_load; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -362,14 +338,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write 
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -386,14 +360,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -410,14 +382,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write 
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -434,14 +404,12 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
@@ -458,15 +426,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: cluster_alloc; errno: 5; imm: off; once: off; write 
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: cluster_alloc; errno: 5; imm: off; once: off; write -b
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -482,15 +446,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: cluster_alloc; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: cluster_alloc; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 
@@ -561,7 +521,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -570,7 +529,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -589,7 +547,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write 
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -598,7 +555,6 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -b
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 
@@ -643,8 +599,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_grow_alloc_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -655,8 +609,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_grow_alloc_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
@@ -667,7 +619,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_grow_write_table; errno: 5; imm: off; once: off
-Failed to flush the L2 table cache: Input/output error
 Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
@@ -679,7 +630,6 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
 
 Event: l1_grow_write_table; errno: 28; imm: off; once: off
-Failed to flush the L2 table cache: No space left on device
 Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
diff --git a/tests/qemu-iotests/071.out b/tests/qemu-iotests/071.out
index 2b40ead..8c6851e 100644
--- a/tests/qemu-iotests/071.out
+++ b/tests/qemu-iotests/071.out
@@ -30,14 +30,10 @@ blkverify: read sector_num=0 nb_sectors=1 contents mismatch in sector 0
 
 === Testing blkdebug through filename ===
 
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 
 === Testing blkdebug through file blockref ===
 
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 
 === Testing blkdebug on existing block device ===
@@ -51,8 +47,6 @@ read failed: Input/output error
 {"return": ""}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
-QEMU_PROG: Failed to flush the L2 table cache: Input/output error
-QEMU_PROG: Failed to flush the refcount block cache: Input/output error
 
 
 === Testing blkverify on existing block device ===
@@ -92,7 +86,5 @@ read failed: Input/output error
 {"return": ""}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
-QEMU_PROG: Failed to flush the L2 table cache: Input/output error
-QEMU_PROG: Failed to flush the refcount block cache: Input/output error
 
 *** done
diff --git a/tests/qemu-iotests/089.out b/tests/qemu-iotests/089.out
index 5b541a3..18f5fdd 100644
--- a/tests/qemu-iotests/089.out
+++ b/tests/qemu-iotests/089.out
@@ -24,8 +24,6 @@ read 512/512 bytes at offset 0
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 512/512 bytes at offset 229376
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Failed to flush the L2 table cache: Input/output error
-Failed to flush the refcount block cache: Input/output error
 read failed: Input/output error
 
 === Testing qemu-img info output ===
diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index adceac1..eaf1e60 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -18,8 +18,8 @@ Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 
 {"return": {}}
 Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
-{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "drv0", "len": 0, "offset": 0, "speed": 0, "type": "mirror"}}
+{"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: mirror"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drv0", "len": 0, "offset": 0, "speed": 0, "type": "mirror"}}
@@ -28,8 +28,8 @@ Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 === Testing active block-commit ===
 
 {"return": {}}
-{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "drv0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
+{"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: commit"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drv0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
diff --git a/tests/qemu-iotests/144.out b/tests/qemu-iotests/144.out
index 410d741..387855c 100644
--- a/tests/qemu-iotests/144.out
+++ b/tests/qemu-iotests/144.out
@@ -12,9 +12,9 @@ Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/
 
 === Performing block-commit on active layer ===
 
-{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
 {"return": {}}
+{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
 
 === Performing Live Snapshot 2 ===
-- 
2.1.4

Re: [Qemu-devel] [PATCH v8 0/4] block: ignore flush requests when storage is clean

[John Snow]

On 07/18/2016 03:39 PM, Denis V. Lunev wrote:
> Changes from v7:
> - fixed 026 test in cached mode (different output)
> 
> Changes from v6:
> - squashed patches 5-6 into patch 4 to avoid test faults on git bissect
> - changed sector number from 0 to 1 in patch 3
> 
> Changes from v5:
> - Removed failed flush traces in block tests 026 071 089
> - Changed BLOCK_JOB_READY event order in block tests 141 144
> 
> Changes from v4:
> - Moved to write generation scheme instead of dirty flag
> - Added retry setup to IDE PIO and FLUSH requests
> 
> Changes from v3:
> - Fixed a typo in commit message
> - Rebased on Kevin'n origin/block
> 
> Changes from v2:
> - Better comments
> - Rebased on latest master
> 
> Changes from v1:
> - Flush requests that should be skipped will now wait for completion
>   of any previous requests already in flight
> - Fixed IDE and AHCI tests to dirty media for new flush behaviour
> - Fixed a problem in IDE CMD_FLUSH_CACHE failure handling
> 
> Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Kevin Wolf <kwolf@redhat.com>
> CC: Max Reitz <mreitz@redhat.com>
> CC: Stefan Hajnoczi <stefanha@redhat.com>
> CC: Fam Zheng <famz@redhat.com>
> CC: John Snow <jsnow@redhat.com>
> 
> Evgeny Yakovlev (4):
>   ide: refactor retry_unit set and clear into separate function
>   ide: set retry_unit for PIO and FLUSH requests
>   tests: in IDE and AHCI tests perform DMA write before flushing
>   block: ignore flush requests when storage is clean
> 
>  block.c                            |  3 +++
>  block/io.c                         | 21 ++++++++++++++++
>  hw/ide/core.c                      | 24 +++++++++++++-----
>  include/block/block_int.h          |  5 ++++
>  tests/ahci-test.c                  | 34 ++++++++++++++++++++++++--
>  tests/ide-test.c                   | 43 ++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/026.out         | 50 --------------------------------------
>  tests/qemu-iotests/026.out.nocache | 50 --------------------------------------
>  tests/qemu-iotests/071.out         |  8 ------
>  tests/qemu-iotests/089.out         |  2 --
>  tests/qemu-iotests/141.out         |  4 +--
>  tests/qemu-iotests/144.out         |  2 +-
>  12 files changed, 125 insertions(+), 121 deletions(-)
> 

Thanks so much for the quick respin, sorry for all the hassle!

Thanks Denis & Evgeny!

Thanks, applied to my IDE tree:

https://github.com/jnsnow/qemu/commits/ide
https://github.com/jnsnow/qemu.git

--js