[Qemu-devel] [PULL 00/13] Block layer patches

[Qemu-devel] [PULL 00/13] Block layer patches

[Kevin Wolf]

The following changes since commit 6d9dd5fb9d0e9f4a174f53a0e20a39fbe809c71e:

  Merge remote-tracking branch 'remotes/armbru/tags/pull-qobject-2018-07-27-v2' into staging (2018-07-30 09:55:47 +0100)

are available in the git repository at:

  git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to 1239ac241fe170bb9fcf0be74bfff04f6f1c2560:

  qemu-iotests: Test query-blockstats with -drive and -blockdev (2018-07-30 15:35:37 +0200)

----------------------------------------------------------------
Block layer patches:

- qemu-img convert -C is now required to enable copy offloading
- file-posix: Fix write_zeroes with unmap on block devices (would fall
  back to explicit writes on recent kernels)
- Fix query-blockstats interface for use with -blockdev
- Minor fixes and documentation updates

----------------------------------------------------------------
Fam Zheng (6):
      file-posix: Handle EINTR in preallocation=full write
      docs: Describe using images in writing iotests
      iotests: Don't lock /dev/null in 226
      Revert "qemu-img: Document copy offloading implications with -S and -c"
      qemu-img: Add -C option for convert with copy offloading
      iotests: Add test for 'qemu-img convert -C' compatibility

KONRAD Frederic (1):
      qcow: fix a reference leak

Kevin Wolf (5):
      block: Fix documentation for BDRV_REQ_MAY_UNMAP
      file-posix: Fix write_zeroes with unmap on block devices
      block/qapi: Add 'qdev' field to query-blockstats result
      block/qapi: Include anonymous BBs in query-blockstats
      qemu-iotests: Test query-blockstats with -drive and -blockdev

Leonid Bloch (1):
      qcow2: A grammar fix in conflicting cache sizing error message

 qapi/block-core.json       |  14 +++-
 include/block/block.h      |  11 +--
 block/file-posix.c         |  62 ++++++++++----
 block/qapi.c               |  16 +++-
 block/qcow.c               |   1 +
 block/qcow2.c              |   2 +-
 qemu-img.c                 |  21 ++++-
 docs/devel/testing.rst     |  11 +++
 qemu-img-cmds.hx           |   2 +-
 qemu-img.texi              |  14 ++--
 tests/qemu-iotests/082     |   8 ++
 tests/qemu-iotests/082.out |  11 +++
 tests/qemu-iotests/103.out |   4 +-
 tests/qemu-iotests/137.out |   2 +-
 tests/qemu-iotests/226     |   4 +-
 tests/qemu-iotests/227     | 101 ++++++++++++++++++++++
 tests/qemu-iotests/227.out | 205 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 18 files changed, 449 insertions(+), 41 deletions(-)
 create mode 100755 tests/qemu-iotests/227
 create mode 100644 tests/qemu-iotests/227.out

[Qemu-devel] [PULL 01/13] qcow: fix a reference leak

[Kevin Wolf]

From: KONRAD Frederic <frederic.konrad@adacore.com>

Since 42a3e1ab367cdf38cce093de24eb406b99a4ef96 qemu asserts when using the
vvfat driver:

git clone git://qemu.org/qemu.git
cd qemu
./configure --target-list=ppc-softmmu --enable-debug
make -j8
mkdir foo
touch foo/hello
./ppc-softmmu/qemu-system-ppc -M prep --nographic --monitor null             \
                              -hda fat:rw:./foo

"Ctrl-C"

qemu-system-ppc: block.c:3368: bdrv_close_all: Assertion                     \
   `((&all_bdrv_states)->tqh_first == ((void *)0))' failed.

This is because we reference bs twice in qcow_co_create(..) one time in
bdrv_open_blockdev_ref(..) and in blk_insert_bs(..) but we unref it only once
in blk_unref which leads to the reference leak.

Note that I didn't tested much QCOW after this change as I don't use it much.

Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/qcow.c b/block/qcow.c
index 102d058d1c..385d935258 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -938,6 +938,7 @@ static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
     ret = 0;
 exit:
     blk_unref(qcow_blk);
+    bdrv_unref(bs);
     qcrypto_block_free(crypto);
     return ret;
 }
-- 
2.13.6

[Qemu-devel] [PULL 02/13] qcow2: A grammar fix in conflicting cache sizing error message

[Kevin Wolf]

From: Leonid Bloch <lbloch@janustech.com>

Signed-off-by: Leonid Bloch <lbloch@janustech.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c              | 2 +-
 tests/qemu-iotests/103.out | 4 ++--
 tests/qemu-iotests/137.out | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 6162ed8be2..ec9e6238a0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -797,7 +797,7 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
         if (l2_cache_size_set && refcount_cache_size_set) {
             error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
                        " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set "
-                       "the same time");
+                       "at the same time");
             return;
         } else if (*l2_cache_size > combined_cache_size) {
             error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed "
diff --git a/tests/qemu-iotests/103.out b/tests/qemu-iotests/103.out
index bd45d3875a..bd9eec3250 100644
--- a/tests/qemu-iotests/103.out
+++ b/tests/qemu-iotests/103.out
@@ -5,10 +5,10 @@ wrote 65536/65536 bytes at offset 0
 
 === Testing invalid option combinations ===
 
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
 can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
-can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index 96724a6c33..6a2ffc71fd 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -16,7 +16,7 @@ read 33554432/33554432 bytes at offset 0
 === Try setting some invalid values ===
 
 Parameter 'lazy-refcounts' expects 'on' or 'off'
-cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
 l2-cache-size may not exceed cache-size
 refcount-cache-size may not exceed cache-size
 L2 cache size too big
-- 
2.13.6

[Qemu-devel] [PULL 03/13] file-posix: Handle EINTR in preallocation=full write

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/file-posix.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block/file-posix.c b/block/file-posix.c
index ad299beb38..928b863ced 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1646,6 +1646,9 @@ static int handle_aiocb_truncate(RawPosixAIOData *aiocb)
             num = MIN(left, 65536);
             result = write(fd, buf, num);
             if (result < 0) {
+                if (errno == EINTR) {
+                    continue;
+                }
                 result = -errno;
                 error_setg_errno(errp, -result,
                                  "Could not write zeros for preallocation");
-- 
2.13.6

[Qemu-devel] [PULL 04/13] docs: Describe using images in writing iotests

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 docs/devel/testing.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 5e19cd50da..8e1fa3a66e 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -255,6 +255,17 @@ comparable library support for invoking and interacting with QEMU programs. If
 you opt for Python, it is strongly recommended to write Python 3 compatible
 code.
 
+Both Python and Bash frameworks in iotests provide helpers to manage test
+images. They can be used to create and clean up images under the test
+directory. If no I/O or any protocol specific feature is needed, it is often
+more convenient to use the pseudo block driver, ``null-co://``, as the test
+image, which doesn't require image creation or cleaning up. Avoid system-wide
+devices or files whenever possible, such as ``/dev/null`` or ``/dev/zero``.
+Otherwise, image locking implications have to be considered.  For example,
+another application on the host may have locked the file, possibly leading to a
+test failure.  If using such devices are explicitly desired, consider adding
+``locking=off`` option to disable image locking.
+
 Docker based tests
 ==================
 
-- 
2.13.6

[Qemu-devel] [PULL 05/13] iotests: Don't lock /dev/null in 226

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

On my system (Fedora 28), this script reports a 'failed to get
"consistent read" lock' error. Following docs/devel/testing.rst, it's
better to add locking=off here.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/226 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/226 b/tests/qemu-iotests/226
index 211ea9888a..8ec3e612dd 100755
--- a/tests/qemu-iotests/226
+++ b/tests/qemu-iotests/226
@@ -56,10 +56,10 @@ for PROTO in "file" "host_device" "host_cdrom"; do
     echo
     echo "== Testing RO =="
     $QEMU_IO -c "open -r -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
     echo "== Testing RW =="
     $QEMU_IO -c "open -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
 done
 
 # success, all done
-- 
2.13.6

[Qemu-devel] [PULL 06/13] Revert "qemu-img: Document copy offloading implications with -S and -c"

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

This reverts commit eb461485f4558e362fab905735b50987505bca44.

Now that we introduce an explicit option, these implicit rules are not
used.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.texi | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/qemu-img.texi b/qemu-img.texi
index 5853cd18d1..aeb1b9e66c 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -96,8 +96,7 @@ will enumerate information about backing files in a disk image chain. Refer
 below for further description.
 
 @item -c
-indicates that target image must be compressed (qcow format only). If this
-option is used, copy offloading will not be attempted.
+indicates that target image must be compressed (qcow format only)
 
 @item -h
 with or without a command shows help and lists the supported formats
@@ -116,8 +115,7 @@ in case both @var{-q} and @var{-p} options are used.
 indicates the consecutive number of bytes that must contain only zeros
 for qemu-img to create a sparse image during conversion. This value is rounded
 down to the nearest 512 bytes. You may use the common size suffixes like
-@code{k} for kilobytes. If this option is used, copy offloading will not be
-attempted.
+@code{k} for kilobytes.
 
 @item -t @var{cache}
 specifies the cache mode that should be used with the (destination) file. See
-- 
2.13.6

[Qemu-devel] [PULL 07/13] qemu-img: Add -C option for convert with copy offloading

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.c       | 21 +++++++++++++++++----
 qemu-img-cmds.hx |  2 +-
 qemu-img.texi    |  8 +++++++-
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 9b7506b8ae..1acddf693c 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2024,11 +2024,12 @@ static int img_convert(int argc, char **argv)
          skip_create = false, progress = false, tgt_image_opts = false;
     int64_t ret = -EINVAL;
     bool force_share = false;
+    bool explict_min_sparse = false;
 
     ImgConvertState s = (ImgConvertState) {
         /* Need at least 4k of zeros for sparse detection */
         .min_sparse         = 8,
-        .copy_range         = true,
+        .copy_range         = false,
         .buf_sectors        = IO_BUF_SIZE / BDRV_SECTOR_SIZE,
         .wr_in_order        = true,
         .num_coroutines     = 8,
@@ -2043,7 +2044,7 @@ static int img_convert(int argc, char **argv)
             {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":hf:O:B:co:l:S:pt:T:qnm:WU",
+        c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WU",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -2067,9 +2068,11 @@ static int img_convert(int argc, char **argv)
         case 'B':
             out_baseimg = optarg;
             break;
+        case 'C':
+            s.copy_range = true;
+            break;
         case 'c':
             s.compressed = true;
-            s.copy_range = false;
             break;
         case 'o':
             if (!is_valid_option_list(optarg)) {
@@ -2112,7 +2115,7 @@ static int img_convert(int argc, char **argv)
             }
 
             s.min_sparse = sval / BDRV_SECTOR_SIZE;
-            s.copy_range = false;
+            explict_min_sparse = true;
             break;
         }
         case 'p':
@@ -2172,6 +2175,16 @@ static int img_convert(int argc, char **argv)
         goto fail_getopt;
     }
 
+    if (s.compressed && s.copy_range) {
+        error_report("Cannot enable copy offloading when -c is used");
+        goto fail_getopt;
+    }
+
+    if (explict_min_sparse && s.copy_range) {
+        error_report("Cannot enable copy offloading when -S is used");
+        goto fail_getopt;
+    }
+
     if (tgt_image_opts && !skip_create) {
         error_report("--target-image-opts requires use of -n flag");
         goto fail_getopt;
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 69758fb6e8..1526f327a5 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -44,7 +44,7 @@ STEXI
 ETEXI
 
 DEF("convert", img_convert,
-    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] filename [filename2 [...]] output_filename")
+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] filename [filename2 [...]] output_filename")
 STEXI
 @item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
 ETEXI
diff --git a/qemu-img.texi b/qemu-img.texi
index aeb1b9e66c..3b6710a580 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -169,6 +169,12 @@ Number of parallel coroutines for the convert process
 Allow out-of-order writes to the destination. This option improves performance,
 but is only recommended for preallocated devices like host devices or other
 raw block devices.
+@item -C
+Try to use copy offloading to move data from source image to target. This may
+improve performance if the data is remote, such as with NFS or iSCSI backends,
+but will not automatically sparsify zero sectors, and may result in a fully
+allocated target image depending on the host support for getting allocation
+information.
 @end table
 
 Parameters to dd subcommand:
@@ -319,7 +325,7 @@ Error on reading data
 
 @end table
 
-@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
+@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
 
 Convert the disk image @var{filename} or a snapshot @var{snapshot_param}
 to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c}
-- 
2.13.6

[Qemu-devel] [PULL 08/13] iotests: Add test for 'qemu-img convert -C' compatibility

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/082     |  8 ++++++++
 tests/qemu-iotests/082.out | 11 +++++++++++
 2 files changed, 19 insertions(+)

diff --git a/tests/qemu-iotests/082 b/tests/qemu-iotests/082
index a872f771a6..3e605d52d1 100755
--- a/tests/qemu-iotests/082
+++ b/tests/qemu-iotests/082
@@ -158,6 +158,14 @@ run_qemu_img convert -o help
 run_qemu_img convert -O bochs -o help
 
 echo
+echo === convert: -C and other options ===
+
+# Adding the help option to a command without other -o options
+run_qemu_img convert -C -S 4k -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+run_qemu_img convert -C -S 8k -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+run_qemu_img convert -C -c -O $IMGFMT "$TEST_IMG" "$TEST_IMG".target
+
+echo
 echo === amend: Options specified more than once ===
 
 # Last -f should win
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index 60ef87c276..19e9fb13ff 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -508,6 +508,17 @@ size             Virtual disk size
 Testing: convert -O bochs -o help
 qemu-img: Format driver 'bochs' does not support image creation
 
+=== convert: -C and other options ===
+
+Testing: convert -C -S 4k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -S is used
+
+Testing: convert -C -S 8k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -S is used
+
+Testing: convert -C -c -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
+qemu-img: Cannot enable copy offloading when -c is used
+
 === amend: Options specified more than once ===
 
 Testing: amend -f foo -f qcow2 -o lazy_refcounts=on TEST_DIR/t.qcow2
-- 
2.13.6

[Qemu-devel] [PULL 09/13] block: Fix documentation for BDRV_REQ_MAY_UNMAP

[Kevin Wolf]

BDRV_REQ_MAY_UNMAP in a write_zeroes request does not only allow the
driver to unmap the blocks, but it actively requests that the blocks be
unmapped afterwards if at all possible.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block.h | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index f85e3a6ed3..4e0871aaf9 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -43,11 +43,12 @@ typedef struct BlockFragInfo {
 typedef enum {
     BDRV_REQ_COPY_ON_READ       = 0x1,
     BDRV_REQ_ZERO_WRITE         = 0x2,
-    /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
-     * is allowed to optimize a write zeroes request by unmapping (discarding)
-     * blocks if it is guaranteed that the result will read back as
-     * zeroes. The flag is only passed to the driver if the block device is
-     * opened with BDRV_O_UNMAP.
+
+    /*
+     * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
+     * that the block driver should unmap (discard) blocks if it is guaranteed
+     * that the result will read back as zeroes. The flag is only passed to the
+     * driver if the block device is opened with BDRV_O_UNMAP.
      */
     BDRV_REQ_MAY_UNMAP          = 0x4,
 
-- 
2.13.6

[Qemu-devel] [PULL 10/13] file-posix: Fix write_zeroes with unmap on block devices

[Kevin Wolf]

The BLKDISCARD ioctl doesn't guarantee that the discarded blocks read as
all-zero afterwards, so don't try to abuse it for zero writing. We try
to only use this if BLKDISCARDZEROES tells us that it is safe, but this
is unreliable on older kernels and a constant 0 in newer kernels. In
other words, this code path is never actually used with newer kernels,
so we don't even try to unmap while writing zeros.

This patch removes the abuse of discard for writing zeroes from
file-posix and instead adds a new function that uses interfaces that are
actually meant to deallocate and zero out at the same time. Only if
those fail, it falls back to zeroing out without unmap. We never fall
back to a discard operation any more that may or may not result in
zeros.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/file-posix.c | 59 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 15 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 928b863ced..fe83cbf0eb 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -648,7 +648,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     }
 #endif
 
-    bs->supported_zero_flags = s->discard_zeroes ? BDRV_REQ_MAY_UNMAP : 0;
+    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
     ret = 0;
 fail:
     if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
@@ -1487,6 +1487,35 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
     return -ENOTSUP;
 }
 
+static ssize_t handle_aiocb_write_zeroes_unmap(RawPosixAIOData *aiocb)
+{
+    BDRVRawState *s G_GNUC_UNUSED = aiocb->bs->opaque;
+    int ret;
+
+    /* First try to write zeros and unmap at the same time */
+
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+    ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+                       aiocb->aio_offset, aiocb->aio_nbytes);
+    if (ret != -ENOTSUP) {
+        return ret;
+    }
+#endif
+
+#ifdef CONFIG_XFS
+    if (s->is_xfs) {
+        /* xfs_discard() guarantees that the discarded area reads as all-zero
+         * afterwards, so we can use it here. */
+        return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes);
+    }
+#endif
+
+    /* If we couldn't manage to unmap while guaranteed that the area reads as
+     * all-zero afterwards, just write zeroes without unmapping */
+    ret = handle_aiocb_write_zeroes(aiocb);
+    return ret;
+}
+
 #ifndef HAVE_COPY_FILE_RANGE
 static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
                              off_t *out_off, size_t len, unsigned int flags)
@@ -1732,6 +1761,9 @@ static int aio_worker(void *arg)
     case QEMU_AIO_WRITE_ZEROES:
         ret = handle_aiocb_write_zeroes(aiocb);
         break;
+    case QEMU_AIO_WRITE_ZEROES | QEMU_AIO_DISCARD:
+        ret = handle_aiocb_write_zeroes_unmap(aiocb);
+        break;
     case QEMU_AIO_COPY_RANGE:
         ret = handle_aiocb_copy_range(aiocb);
         break;
@@ -2556,15 +2588,13 @@ static int coroutine_fn raw_co_pwrite_zeroes(
     int bytes, BdrvRequestFlags flags)
 {
     BDRVRawState *s = bs->opaque;
+    int operation = QEMU_AIO_WRITE_ZEROES;
 
-    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_WRITE_ZEROES);
-    } else if (s->discard_zeroes) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_DISCARD);
+    if (flags & BDRV_REQ_MAY_UNMAP) {
+        operation |= QEMU_AIO_DISCARD;
     }
-    return -ENOTSUP;
+
+    return paio_submit_co(bs, s->fd, offset, NULL, bytes, operation);
 }
 
 static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
@@ -3057,20 +3087,19 @@ static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs,
     int64_t offset, int bytes, BdrvRequestFlags flags)
 {
     BDRVRawState *s = bs->opaque;
+    int operation = QEMU_AIO_WRITE_ZEROES | QEMU_AIO_BLKDEV;
     int rc;
 
     rc = fd_open(bs);
     if (rc < 0) {
         return rc;
     }
-    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_WRITE_ZEROES|QEMU_AIO_BLKDEV);
-    } else if (s->discard_zeroes) {
-        return paio_submit_co(bs, s->fd, offset, NULL, bytes,
-                              QEMU_AIO_DISCARD|QEMU_AIO_BLKDEV);
+
+    if (flags & BDRV_REQ_MAY_UNMAP) {
+        operation |= QEMU_AIO_DISCARD;
     }
-    return -ENOTSUP;
+
+    return paio_submit_co(bs, s->fd, offset, NULL, bytes, operation);
 }
 
 static int coroutine_fn hdev_co_create_opts(const char *filename, QemuOpts *opts,
-- 
2.13.6

[Qemu-devel] [PULL 11/13] block/qapi: Add 'qdev' field to query-blockstats result

[Kevin Wolf]

Like for query-block, the client needs to identify which BlockBackend
the returned data is for. Anonymous BlockBackends are identified by the
device model they are attached to. Add a 'qdev' field that contains the
qdev ID or QOM path of the attached device model.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qapi/block-core.json | 14 ++++++++++----
 block/qapi.c         | 10 ++++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index d40d5ecc3b..5b9084a394 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -866,6 +866,9 @@
 #
 # @node-name: The node name of the device. (Since 2.3)
 #
+# @qdev: The qdev ID, or if no ID is assigned, the QOM path of the block
+#        device. (since 3.0)
+#
 # @stats:  A @BlockDeviceStats for the device.
 #
 # @parent: This describes the file block device if it has one.
@@ -879,7 +882,7 @@
 # Since: 0.14.0
 ##
 { 'struct': 'BlockStats',
-  'data': {'*device': 'str', '*node-name': 'str',
+  'data': {'*device': 'str', '*qdev': 'str', '*node-name': 'str',
            'stats': 'BlockDeviceStats',
            '*parent': 'BlockStats',
            '*backing': 'BlockStats'} }
@@ -941,7 +944,8 @@
 #                "idle_time_ns":2953431879,
 #                "account_invalid":true,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[23]"
 #          },
 #          {
 #             "device":"ide1-cd0",
@@ -959,7 +963,8 @@
 #                "wr_merged":0,
 #                "account_invalid":false,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[24]"
 #          },
 #          {
 #             "device":"floppy0",
@@ -977,7 +982,8 @@
 #                "wr_merged":0,
 #                "account_invalid":false,
 #                "account_failed":false
-#             }
+#             },
+#             "qdev": "/machine/unattached/device[16]"
 #          },
 #          {
 #             "device":"sd0",
diff --git a/block/qapi.c b/block/qapi.c
index e12968fec8..50f867d634 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -597,11 +597,21 @@ BlockStatsList *qmp_query_blockstats(bool has_query_nodes,
             BlockStatsList *info = g_malloc0(sizeof(*info));
             AioContext *ctx = blk_get_aio_context(blk);
             BlockStats *s;
+            char *qdev;
 
             aio_context_acquire(ctx);
             s = bdrv_query_bds_stats(blk_bs(blk), true);
             s->has_device = true;
             s->device = g_strdup(blk_name(blk));
+
+            qdev = blk_get_attached_dev_id(blk);
+            if (qdev && *qdev) {
+                s->has_qdev = true;
+                s->qdev = qdev;
+            } else {
+                g_free(qdev);
+            }
+
             bdrv_query_blk_stats(s->stats, blk);
             aio_context_release(ctx);
 
-- 
2.13.6

[Qemu-devel] [PULL 12/13] block/qapi: Include anonymous BBs in query-blockstats

[Kevin Wolf]

Consistent with query-block, query-blockstats should not only include
named BlockBackends, but also those that are anonymous, but belong to a
device model.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/qapi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/qapi.c b/block/qapi.c
index 50f867d634..339727f0f4 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -593,12 +593,16 @@ BlockStatsList *qmp_query_blockstats(bool has_query_nodes,
             p_next = &info->next;
         }
     } else {
-        for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
+        for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
             BlockStatsList *info = g_malloc0(sizeof(*info));
             AioContext *ctx = blk_get_aio_context(blk);
             BlockStats *s;
             char *qdev;
 
+            if (!*blk_name(blk) && !blk_get_attached_dev(blk)) {
+                continue;
+            }
+
             aio_context_acquire(ctx);
             s = bdrv_query_bds_stats(blk_bs(blk), true);
             s->has_device = true;
-- 
2.13.6

[Qemu-devel] [PULL 13/13] qemu-iotests: Test query-blockstats with -drive and -blockdev

[Kevin Wolf]

Make sure that query-blockstats returns information for every
BlockBackend that is named or attached to a device model (or both).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/227     | 101 ++++++++++++++++++++++
 tests/qemu-iotests/227.out | 205 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 307 insertions(+)
 create mode 100755 tests/qemu-iotests/227
 create mode 100644 tests/qemu-iotests/227.out

diff --git a/tests/qemu-iotests/227 b/tests/qemu-iotests/227
new file mode 100755
index 0000000000..9a5f7f9f14
--- /dev/null
+++ b/tests/qemu-iotests/227
@@ -0,0 +1,101 @@
+#!/bin/bash
+#
+# Test query-blockstats with different ways to create a BB
+#
+# Copyright (C) 2018 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=kwolf@redhat.com
+
+seq=$(basename $0)
+echo "QA output created by $seq"
+
+here=$PWD
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt generic
+_supported_proto file
+_supported_os Linux
+
+function do_run_qemu()
+{
+    echo Testing: "$@"
+    $QEMU -nographic -qmp-pretty stdio -serial none "$@"
+    echo
+}
+
+function run_qemu()
+{
+    do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_qmp \
+                          | _filter_qemu | _filter_imgfmt \
+                          | _filter_generated_node_ids
+}
+
+echo
+echo '=== blockstats with -drive if=virtio ==='
+echo
+
+run_qemu -drive driver=null-co,if=virtio <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -drive if=none ==='
+echo
+
+run_qemu -drive driver=null-co,if=none <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -blockdev ==='
+echo
+
+run_qemu -blockdev driver=null-co,node-name=null <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+echo
+echo '=== blockstats with -blockdev and -device ==='
+echo
+
+run_qemu -blockdev driver=null-co,node-name=null -device virtio-blk,drive=null,id=virtio0 <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "query-blockstats"}
+{ "execute": "quit" }
+EOF
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/227.out b/tests/qemu-iotests/227.out
new file mode 100644
index 0000000000..736f2e3b11
--- /dev/null
+++ b/tests/qemu-iotests/227.out
@@ -0,0 +1,205 @@
+QA output created by 227
+
+=== blockstats with -drive if=virtio ===
+
+Testing: -drive driver=null-co,if=virtio
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "virtio0",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": true,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": true,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "NODE_NAME",
+            "qdev": "/machine/peripheral-anon/device[0]/virtio-backend"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -drive if=none ===
+
+Testing: -drive driver=null-co,if=none
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "none0",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": true,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": true,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "NODE_NAME"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -blockdev ===
+
+Testing: -blockdev driver=null-co,node-name=null
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+
+=== blockstats with -blockdev and -device ===
+
+Testing: -blockdev driver=null-co,node-name=null -device virtio-blk,drive=null,id=virtio0
+{
+    QMP_VERSION
+}
+{
+    "return": {
+    }
+}
+{
+    "return": [
+        {
+            "device": "",
+            "stats": {
+                "flush_total_time_ns": 0,
+                "wr_highest_offset": 0,
+                "wr_total_time_ns": 0,
+                "failed_wr_operations": 0,
+                "failed_rd_operations": 0,
+                "wr_merged": 0,
+                "wr_bytes": 0,
+                "timed_stats": [
+                ],
+                "failed_flush_operations": 0,
+                "account_invalid": false,
+                "rd_total_time_ns": 0,
+                "flush_operations": 0,
+                "wr_operations": 0,
+                "rd_merged": 0,
+                "rd_bytes": 0,
+                "invalid_flush_operations": 0,
+                "account_failed": false,
+                "rd_operations": 0,
+                "invalid_wr_operations": 0,
+                "invalid_rd_operations": 0
+            },
+            "node-name": "null",
+            "qdev": "/machine/peripheral/virtio0/virtio-backend"
+        }
+    ]
+}
+{
+    "return": {
+    }
+}
+{
+    "timestamp": {
+        "seconds":  TIMESTAMP,
+        "microseconds":  TIMESTAMP
+    },
+    "event": "SHUTDOWN",
+    "data": {
+        "guest": false
+    }
+}
+
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 68f66259b2..b973dc842d 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -224,3 +224,4 @@
 223 rw auto quick
 225 rw auto quick
 226 auto quick
+227 auto quick
-- 
2.13.6

Re: [Qemu-devel] [PULL 00/13] Block layer patches

[Peter Maydell]

On 30 July 2018 at 16:09, Kevin Wolf <kwolf@redhat.com> wrote:
> The following changes since commit 6d9dd5fb9d0e9f4a174f53a0e20a39fbe809c71e:
>
>   Merge remote-tracking branch 'remotes/armbru/tags/pull-qobject-2018-07-27-v2' into staging (2018-07-30 09:55:47 +0100)
>
> are available in the git repository at:
>
>   git://repo.or.cz/qemu/kevin.git tags/for-upstream
>
> for you to fetch changes up to 1239ac241fe170bb9fcf0be74bfff04f6f1c2560:
>
>   qemu-iotests: Test query-blockstats with -drive and -blockdev (2018-07-30 15:35:37 +0200)
>
> ----------------------------------------------------------------
> Block layer patches:
>
> - qemu-img convert -C is now required to enable copy offloading
> - file-posix: Fix write_zeroes with unmap on block devices (would fall
>   back to explicit writes on recent kernels)
> - Fix query-blockstats interface for use with -blockdev
> - Minor fixes and documentation updates
>
> ----------------------------------------------------------------

Applied, thanks.

-- PMM