Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Fri Mar 27 10:13:35 2015 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/block-pull-request:
  block: Document blockdev-add's immaturity
  qemu-iotests: Test unaligned 4k zero write
  block: Fix unaligned zero write
  nvme: Fix unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)

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

6 files changed, 104 insertions, 24 deletions

diff --git a/block.c b/block.c
index 0fe97de..f2f8ae7 100644
--- a/block.c
+++ b/block.c
@@ -3118,6 +3118,19 @@ out:
     return ret;
 }
 
+static inline uint64_t bdrv_get_align(BlockDriverState *bs)
+{
+    /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
+    return MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+}
+
+static inline bool bdrv_req_is_aligned(BlockDriverState *bs,
+                                       int64_t offset, size_t bytes)
+{
+    int64_t align = bdrv_get_align(bs);
+    return !(offset & (align - 1) || (bytes & (align - 1)));
+}
+
 /*
  * Handle a read request in coroutine context
  */
@@ -3128,8 +3141,7 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
     BlockDriver *drv = bs->drv;
     BdrvTrackedRequest req;
 
-    /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
-    uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+    uint64_t align = bdrv_get_align(bs);
     uint8_t *head_buf = NULL;
     uint8_t *tail_buf = NULL;
     QEMUIOVector local_qiov;
@@ -3371,8 +3383,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
     BdrvRequestFlags flags)
 {
     BdrvTrackedRequest req;
-    /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
-    uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+    uint64_t align = bdrv_get_align(bs);
     uint8_t *head_buf = NULL;
     uint8_t *tail_buf = NULL;
     QEMUIOVector local_qiov;
@@ -3471,6 +3482,10 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
         bytes = ROUND_UP(bytes, align);
     }
 
+    if (use_local_qiov) {
+        /* Local buffer may have non-zero data. */
+        flags &= ~BDRV_REQ_ZERO_WRITE;
+    }
     ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
                                use_local_qiov ? &local_qiov : qiov,
                                flags);
@@ -3511,14 +3526,32 @@ int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
                                       int64_t sector_num, int nb_sectors,
                                       BdrvRequestFlags flags)
 {
+    int ret;
+
     trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
 
     if (!(bs->open_flags & BDRV_O_UNMAP)) {
         flags &= ~BDRV_REQ_MAY_UNMAP;
     }
+    if (bdrv_req_is_aligned(bs, sector_num << BDRV_SECTOR_BITS,
+                            nb_sectors << BDRV_SECTOR_BITS)) {
+        ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
+                                BDRV_REQ_ZERO_WRITE | flags);
+    } else {
+        uint8_t *buf;
+        QEMUIOVector local_qiov;
+        size_t bytes = nb_sectors << BDRV_SECTOR_BITS;
+
+        buf = qemu_memalign(bdrv_opt_mem_align(bs), bytes);
+        memset(buf, 0, bytes);
+        qemu_iovec_init(&local_qiov, 1);
+        qemu_iovec_add(&local_qiov, buf, bytes);
 
-    return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
-                             BDRV_REQ_ZERO_WRITE | flags);
+        ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, &local_qiov,
+                                BDRV_REQ_ZERO_WRITE | flags);
+        qemu_vfree(buf);
+    }
+    return ret;
 }
 
 /**
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 0f3dfb9..1e07166 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -222,7 +222,7 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
 
     uint8_t lba_index  = NVME_ID_NS_FLBAS_INDEX(ns->id_ns.flbas);
     uint8_t data_shift = ns->id_ns.lbaf[lba_index].ds;
-    uint64_t data_size = nlb << data_shift;
+    uint64_t data_size = (uint64_t)nlb << data_shift;
     uint64_t aio_slba  = slba << (data_shift - BDRV_SECTOR_BITS);
     int is_write = rw->opcode == NVME_CMD_WRITE ? 1 : 0;
 
diff --git a/qapi/block-core.json b/qapi/block-core.json
index f525b04..7873084 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1721,6 +1721,10 @@
 #
 # Creates a new block device.
 #
+# This command is still a work in progress.  It doesn't support all
+# block drivers, it lacks a matching blockdev-del, and more.  Stay
+# away from it unless you want to help with its development.
+#
 # @options: block device options for the new device
 #
 # Since: 1.7
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7f68760..3a42ad0 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3636,6 +3636,10 @@ blockdev-add
 
 Add a block device.
 
+This command is still a work in progress.  It doesn't support all
+block drivers, it lacks a matching blockdev-del, and more.  Stay away
+from it unless you want to help with its development.
+
 Arguments:
 
 - "options": block driver options
diff --git a/tests/qemu-iotests/033 b/tests/qemu-iotests/033
index ea3351c..4008f10 100755
--- a/tests/qemu-iotests/033
+++ b/tests/qemu-iotests/033
@@ -46,26 +46,39 @@ _supported_os Linux
 size=128M
 _make_test_img $size
 
-echo
-echo "== preparing image =="
-$QEMU_IO -c "write -P 0xa 0x200 0x400" "$TEST_IMG" | _filter_qemu_io
-$QEMU_IO -c "write -P 0xa 0x20000 0x600" "$TEST_IMG" | _filter_qemu_io
-$QEMU_IO -c "write -z 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
+do_test()
+{
+	local align=$1
+	local iocmd=$2
+	local img=$3
+	{
+		echo "open -o driver=$IMGFMT,file.align=$align blkdebug::$img"
+		echo $iocmd
+	} | $QEMU_IO
+}
+
+for align in 512 4k; do
+	echo
+	echo "== preparing image =="
+	do_test $align "write -P 0xa 0x200 0x400" "$TEST_IMG" | _filter_qemu_io
+	do_test $align "write -P 0xa 0x20000 0x600" "$TEST_IMG" | _filter_qemu_io
+	do_test $align "write -z 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
 
-echo
-echo "== verifying patterns (1) =="
-$QEMU_IO -c "read -P 0xa 0x200 0x200" "$TEST_IMG" | _filter_qemu_io
-$QEMU_IO -c "read -P 0x0 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
-$QEMU_IO -c "read -P 0xa 0x20400 0x200" "$TEST_IMG" | _filter_qemu_io
+	echo
+	echo "== verifying patterns (1) =="
+	do_test $align "read -P 0xa 0x200 0x200" "$TEST_IMG" | _filter_qemu_io
+	do_test $align "read -P 0x0 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
+	do_test $align "read -P 0xa 0x20400 0x200" "$TEST_IMG" | _filter_qemu_io
 
-echo
-echo "== rewriting zeroes =="
-$QEMU_IO -c "write -P 0xb 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
-$QEMU_IO -c "write -z 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
+	echo
+	echo "== rewriting zeroes =="
+	do_test $align "write -P 0xb 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
+	do_test $align "write -z 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
 
-echo
-echo "== verifying patterns (2) =="
-$QEMU_IO -c "read -P 0x0 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
+	echo
+	echo "== verifying patterns (2) =="
+	do_test $align "read -P 0x0 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
+done
 
 # success, all done
 echo "*** done"
diff --git a/tests/qemu-iotests/033.out b/tests/qemu-iotests/033.out
index 41475ee..305949f 100644
--- a/tests/qemu-iotests/033.out
+++ b/tests/qemu-iotests/033.out
@@ -26,4 +26,30 @@ wrote 65536/65536 bytes at offset 65536
 == verifying patterns (2) ==
 read 131072/131072 bytes at offset 1024
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== preparing image ==
+wrote 1024/1024 bytes at offset 512
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1536/1536 bytes at offset 131072
+1.500 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (1) ==
+read 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 132096
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== rewriting zeroes ==
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (2) ==
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 *** done