[Qemu-devel] [PATCH 0/2] scsi-disk: Fix an assertion failure

[Qemu-devel] [PATCH 0/2] scsi-disk: Fix an assertion failure

[Fam Zheng]

The first patch fixes the bug, and second patch adds a regression test case.



Fam Zheng (2):
  scsi-disk: Fix assertion failure on WRITE SAME
  virtio-scsi-test: Add test case for tail unaligned WRITE SAME

 hw/scsi/scsi-disk.c      |  3 +++
 tests/virtio-scsi-test.c | 12 +++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

-- 
2.4.3

[Qemu-devel] [PATCH 1/2] scsi-disk: Fix assertion failure on WRITE SAME

[Fam Zheng]

The last portion of an unaligned WRITE SAME command could fail the
assertion in bdrv_aligned_pwritev:

    assert(!qiov || bytes == qiov->size);

Because we updated data->iov.iov_len right above this if block, but
data->qiov still has the old size.

Reinitialize the qiov to make them equal and keep block layer happy.

Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 hw/scsi/scsi-disk.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 64f0694..3f92079 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1683,6 +1683,9 @@ static void scsi_write_same_complete(void *opaque, int ret)
     if (data->iov.iov_len) {
         block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                          data->iov.iov_len, BLOCK_ACCT_WRITE);
+        /* blk_aio_write doesn't like the qiov size being different from
+         * nb_sectors, make sure they match. */
+        qemu_iovec_init_external(&data->qiov, &data->iov, 1);
         r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, data->sector,
                                       &data->qiov, data->iov.iov_len / 512,
                                       scsi_write_same_complete, data);
-- 
2.4.3

[Qemu-devel] [PATCH 2/2] virtio-scsi-test: Add test case for tail unaligned WRITE SAME

[Fam Zheng]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 tests/virtio-scsi-test.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/tests/virtio-scsi-test.c b/tests/virtio-scsi-test.c
index 11ccdd6..afd22c6 100644
--- a/tests/virtio-scsi-test.c
+++ b/tests/virtio-scsi-test.c
@@ -221,9 +221,12 @@ static void hotplug(void)
 static void test_unaligned_write_same(void)
 {
     QVirtIOSCSI *vs;
-    uint8_t buf[512] = { 0 };
-    const uint8_t write_same_cdb[CDB_SIZE] = { 0x41, 0x00, 0x00, 0x00, 0x00,
+    uint8_t buf1[512] = { 0 };
+    uint8_t buf2[512] = { 1 };
+    const uint8_t write_same_cdb_1[CDB_SIZE] = { 0x41, 0x00, 0x00, 0x00, 0x00,
                                                0x01, 0x00, 0x00, 0x02, 0x00 };
+    const uint8_t write_same_cdb_2[CDB_SIZE] = { 0x41, 0x00, 0x00, 0x00, 0x00,
+                                               0x01, 0x00, 0x33, 0x00, 0x00 };
 
     qvirtio_scsi_start("-drive file=blkdebug::null-co://,if=none,id=dr1"
                        ",format=raw,file.align=4k "
@@ -231,7 +234,10 @@ static void test_unaligned_write_same(void)
     vs = qvirtio_scsi_pci_init(PCI_SLOT);
 
     g_assert_cmphex(0, ==,
-        virtio_scsi_do_command(vs, write_same_cdb, NULL, 0, buf, 512));
+        virtio_scsi_do_command(vs, write_same_cdb_1, NULL, 0, buf1, 512));
+
+    g_assert_cmphex(0, ==,
+        virtio_scsi_do_command(vs, write_same_cdb_2, NULL, 0, buf2, 512));
 
     qvirtio_scsi_pci_free(vs);
     qvirtio_scsi_stop();
-- 
2.4.3

Re: [Qemu-devel] [PATCH 0/2] scsi-disk: Fix an assertion failure

[Paolo Bonzini]

On 29/07/2015 10:45, Fam Zheng wrote:
> The first patch fixes the bug, and second patch adds a regression test case.
> 
> 
> 
> Fam Zheng (2):
>   scsi-disk: Fix assertion failure on WRITE SAME
>   virtio-scsi-test: Add test case for tail unaligned WRITE SAME
> 
>  hw/scsi/scsi-disk.c      |  3 +++
>  tests/virtio-scsi-test.c | 12 +++++++++---
>  2 files changed, 12 insertions(+), 3 deletions(-)
> 

Thanks, queued for 2.5.

Paolo