[Qemu-devel] [PATCH v3 0/9] qemu-img convert with copy offloading

[Qemu-devel] [PATCH v3 0/9] qemu-img convert with copy offloading

[Fam Zheng]

v3: Drop RFC.
    Update iotests reference output.
    Address Stefan's comments to v2:
    - Added a TODO for qcow2 copy with refcnt within the same image.
    - Include sys/syscall.h only on Linux.
    - Provide a dummy implementation returning -ENOSYS to reduce #ifdefs.
    - Use aio_ prefix for RawPosixAIOData fields.
    - Iscsi: split patches for code refactoring and device designator query.
    - Iscsi: improve parameter verification, types. don't use meaningless
      offset calculation.
    - Iscsi: set next pointer to NULL.
    - Iscsi: don't free uninitialized pointers.
    - Block backend: check request byte range.
    - Add reviewed-by lines.

v2: - Add iscsi EXTENDED COPY.
    - Design change: bdrv_co_copy_range_{from,to}. [Stefan]
    - Retry upon EINTR. [Stefan]
    - Drop the bounce buffer fallback. It is inefficient to attempt the
      offloaded copy over and over again if the error is returned from the host
      rather than checking our internal state. E.g.  trying copy_file_range
      between two filesystems results in EXDEV, in which case qemu-img.c should
      switch back to the copy path for the remaining sectors.

This series introduces block layer API for copy offloading and makes use of it
in qemu-img convert.

For now we implemented the operation in local file protocol with
copy_file_range(2).  Besides that it's possible to add similar to iscsi, nfs
and potentially more.

As far as its usage goes, in addition to qemu-img convert, we can emulate
offloading in scsi-disk (handle EXTENDED COPY command), and use the API in
block jobs too.

Fam Zheng (9):
  block: Introduce API for copy offloading
  raw: Implement copy offloading
  qcow2: Implement copy offloading
  file-posix: Implement bdrv_co_copy_range
  iscsi: Query and save device designator when opening
  iscsi: Create and use iscsi_co_wait_for_task
  iscsi: Implement copy offloading
  block-backend: Add blk_co_copy_range
  qemu-img: Convert with copy offloading

 block/block-backend.c            |  18 +++
 block/file-posix.c               |  94 +++++++++++-
 block/io.c                       |  91 +++++++++++
 block/iscsi.c                    | 323 ++++++++++++++++++++++++++++++++++-----
 block/qcow2.c                    | 228 +++++++++++++++++++++++----
 block/raw-format.c               |  20 +++
 include/block/block.h            |   4 +
 include/block/block_int.h        |  30 ++++
 include/block/raw-aio.h          |  10 +-
 include/scsi/constants.h         |   5 +
 include/sysemu/block-backend.h   |   4 +
 qemu-img.c                       |  50 +++++-
 tests/qemu-iotests/178.out.qcow2 |   8 +-
 13 files changed, 807 insertions(+), 78 deletions(-)

-- 
2.14.3

[Qemu-devel] [PATCH v3 1/9] block: Introduce API for copy offloading

[Fam Zheng]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/io.c                | 91 +++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  4 +++
 include/block/block_int.h | 30 ++++++++++++++++
 3 files changed, 125 insertions(+)

diff --git a/block/io.c b/block/io.c
index bd9a19a9c4..d274e9525f 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2826,3 +2826,94 @@ void bdrv_unregister_buf(BlockDriverState *bs, void *host)
         bdrv_unregister_buf(child->bs, host);
     }
 }
+
+static int bdrv_co_copy_range_internal(BdrvChild *src,
+                                       uint64_t src_offset,
+                                       BdrvChild *dst,
+                                       uint64_t dst_offset,
+                                       uint64_t bytes, BdrvRequestFlags flags,
+                                       bool recurse_src)
+{
+    int ret;
+
+    if (!src || !dst || !src->bs || !dst->bs) {
+        return -ENOMEDIUM;
+    }
+    ret = bdrv_check_byte_request(src->bs, src_offset, bytes);
+    if (ret) {
+        return ret;
+    }
+
+    ret = bdrv_check_byte_request(dst->bs, dst_offset, bytes);
+    if (ret) {
+        return ret;
+    }
+    if (flags & BDRV_REQ_ZERO_WRITE) {
+        return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags);
+    }
+
+    if (!src->bs->drv->bdrv_co_copy_range_from
+        || !dst->bs->drv->bdrv_co_copy_range_to
+        || src->bs->encrypted || dst->bs->encrypted) {
+        return -ENOTSUP;
+    }
+    if (recurse_src) {
+        return src->bs->drv->bdrv_co_copy_range_from(src->bs,
+                                                     src, src_offset,
+                                                     dst, dst_offset,
+                                                     bytes, flags);
+    } else {
+        return dst->bs->drv->bdrv_co_copy_range_to(dst->bs,
+                                                   src, src_offset,
+                                                   dst, dst_offset,
+                                                   bytes, flags);
+    }
+}
+
+/* Copy range from @bs to @dst. */
+int bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
+                            BdrvChild *dst, uint64_t dst_offset,
+                            uint64_t bytes, BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset,
+                                       bytes, flags, true);
+}
+
+/* Copy range from @src to @bs. Should only be called by block drivers when @bs
+ * is the leaf. */
+int bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset,
+                          BdrvChild *dst, uint64_t dst_offset,
+                          uint64_t bytes, BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset,
+                                       bytes, flags, false);
+}
+
+int bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset,
+                       BdrvChild *dst, uint64_t dst_offset,
+                       uint64_t bytes, BdrvRequestFlags flags)
+{
+    BdrvTrackedRequest src_req, dst_req;
+    BlockDriverState *src_bs = src->bs;
+    BlockDriverState *dst_bs = dst->bs;
+    int ret;
+
+    bdrv_inc_in_flight(src_bs);
+    bdrv_inc_in_flight(dst_bs);
+    tracked_request_begin(&src_req, src_bs, src_offset,
+                          bytes, BDRV_TRACKED_READ);
+    tracked_request_begin(&dst_req, dst_bs, dst_offset,
+                          bytes, BDRV_TRACKED_WRITE);
+
+    wait_serialising_requests(&src_req);
+    wait_serialising_requests(&dst_req);
+    ret = bdrv_co_copy_range_from(src, src_offset,
+                                  dst, dst_offset,
+                                  bytes, flags);
+
+    tracked_request_end(&src_req);
+    tracked_request_end(&dst_req);
+    bdrv_dec_in_flight(src_bs);
+    bdrv_dec_in_flight(dst_bs);
+    return ret;
+}
diff --git a/include/block/block.h b/include/block/block.h
index cdec3639a3..72ac011b2b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -604,4 +604,8 @@ bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
  */
 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
 void bdrv_unregister_buf(BlockDriverState *bs, void *host);
+
+int bdrv_co_copy_range(BdrvChild *bs, uint64_t offset,
+                       BdrvChild *src, uint64_t src_offset,
+                       uint64_t bytes, BdrvRequestFlags flags);
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index c4dd1d4bb8..305c29b75e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -206,6 +206,29 @@ struct BlockDriver {
     int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
         int64_t offset, int bytes);
 
+    /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
+     * and invoke bdrv_co_copy_range_from(child, ...), or invoke
+     * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
+     */
+    int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
+                                                BdrvChild *src,
+                                                uint64_t offset,
+                                                BdrvChild *dst,
+                                                uint64_t dst_offset,
+                                                uint64_t bytes, BdrvRequestFlags flags);
+
+    /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
+     * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
+     * operation if @bs is the leaf and @src has the same BlockDriver.  Return
+     * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
+     */
+    int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
+                                              BdrvChild *src,
+                                              uint64_t src_offset,
+                                              BdrvChild *dst,
+                                              uint64_t dst_offset,
+                                              uint64_t bytes, BdrvRequestFlags flags);
+
     /*
      * Building block for bdrv_block_status[_above] and
      * bdrv_is_allocated[_above].  The driver should answer only
@@ -1090,4 +1113,11 @@ void bdrv_dec_in_flight(BlockDriverState *bs);
 
 void blockdev_close_all_bdrv_states(void);
 
+int bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
+                            BdrvChild *dst, uint64_t dst_offset,
+                            uint64_t bytes, BdrvRequestFlags flags);
+int bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset,
+                            BdrvChild *dst, uint64_t dst_offset,
+                            uint64_t bytes, BdrvRequestFlags flags);
+
 #endif /* BLOCK_INT_H */
-- 
2.14.3

[Qemu-devel] [PATCH v3 2/9] raw: Implement copy offloading

[Fam Zheng]

Just pass down to ->file.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/raw-format.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/block/raw-format.c b/block/raw-format.c
index a378547c99..febddf00c0 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -482,6 +482,24 @@ static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
     return bdrv_probe_geometry(bs->file->bs, geo);
 }
 
+static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
+                                               BdrvChild *src, uint64_t src_offset,
+                                               BdrvChild *dst, uint64_t dst_offset,
+                                               uint64_t bytes, BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
+                                   bytes, flags);
+}
+
+static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
+                                             BdrvChild *src, uint64_t src_offset,
+                                             BdrvChild *dst, uint64_t dst_offset,
+                                             uint64_t bytes, BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_to(src, src_offset, bs->file, dst_offset, bytes,
+                                 flags);
+}
+
 BlockDriver bdrv_raw = {
     .format_name          = "raw",
     .instance_size        = sizeof(BDRVRawState),
@@ -498,6 +516,8 @@ BlockDriver bdrv_raw = {
     .bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
     .bdrv_co_pdiscard     = &raw_co_pdiscard,
     .bdrv_co_block_status = &raw_co_block_status,
+    .bdrv_co_copy_range_from = &raw_co_copy_range_from,
+    .bdrv_co_copy_range_to  = &raw_co_copy_range_to,
     .bdrv_truncate        = &raw_truncate,
     .bdrv_getlength       = &raw_getlength,
     .has_variable_length  = true,
-- 
2.14.3

[Qemu-devel] [PATCH v3 3/9] qcow2: Implement copy offloading

[Fam Zheng]

The two callbacks are implemented quite similarly to the read/write
functions: bdrv_co_copy_range_from maps for read and calls into bs->file
or bs->backing depending on the allocation status; bdrv_co_copy_range_to
maps for write and calls into bs->file.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/qcow2.c | 228 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 198 insertions(+), 30 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 2f36e632f9..07e38b548a 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1755,6 +1755,31 @@ static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
     return status;
 }
 
+static int qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta *l2meta)
+{
+    int ret = 0;
+
+    while (l2meta != NULL) {
+        QCowL2Meta *next;
+
+        if (!ret) {
+            ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
+        }
+
+        /* Take the request off the list of running requests */
+        if (l2meta->nb_clusters != 0) {
+            QLIST_REMOVE(l2meta, next_in_flight);
+        }
+
+        qemu_co_queue_restart_all(&l2meta->dependent_requests);
+
+        next = l2meta->next;
+        g_free(l2meta);
+        l2meta = next;
+    }
+    return ret;
+}
+
 static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
                                         uint64_t bytes, QEMUIOVector *qiov,
                                         int flags)
@@ -2041,24 +2066,10 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
             }
         }
 
-        while (l2meta != NULL) {
-            QCowL2Meta *next;
-
-            ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
-            if (ret < 0) {
-                goto fail;
-            }
-
-            /* Take the request off the list of running requests */
-            if (l2meta->nb_clusters != 0) {
-                QLIST_REMOVE(l2meta, next_in_flight);
-            }
-
-            qemu_co_queue_restart_all(&l2meta->dependent_requests);
-
-            next = l2meta->next;
-            g_free(l2meta);
-            l2meta = next;
+        ret = qcow2_handle_l2meta(bs, l2meta);
+        l2meta = NULL;
+        if (ret) {
+            goto fail;
         }
 
         bytes -= cur_bytes;
@@ -2069,18 +2080,7 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
     ret = 0;
 
 fail:
-    while (l2meta != NULL) {
-        QCowL2Meta *next;
-
-        if (l2meta->nb_clusters != 0) {
-            QLIST_REMOVE(l2meta, next_in_flight);
-        }
-        qemu_co_queue_restart_all(&l2meta->dependent_requests);
-
-        next = l2meta->next;
-        g_free(l2meta);
-        l2meta = next;
-    }
+    qcow2_handle_l2meta(bs, l2meta);
 
     qemu_co_mutex_unlock(&s->lock);
 
@@ -3267,6 +3267,172 @@ static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
     return ret;
 }
 
+static int qcow2_co_copy_range_from(BlockDriverState *bs,
+                                    BdrvChild *src, uint64_t src_offset,
+                                    BdrvChild *dst, uint64_t dst_offset,
+                                    uint64_t bytes, BdrvRequestFlags flags)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int offset_in_cluster;
+    int ret;
+    unsigned int cur_bytes; /* number of bytes in current iteration */
+    uint64_t cluster_offset = 0;
+    BdrvChild *child = NULL;
+
+    assert(!bs->encrypted);
+    qemu_co_mutex_lock(&s->lock);
+
+    while (bytes != 0) {
+
+        /* prepare next request */
+        cur_bytes = MIN(bytes, INT_MAX);
+
+        ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, &cluster_offset);
+        if (ret < 0) {
+            goto out;
+        }
+
+        offset_in_cluster = offset_into_cluster(s, src_offset);
+
+        switch (ret) {
+        case QCOW2_CLUSTER_UNALLOCATED:
+            if (bs->backing) {
+                child = bs->backing;
+            } else {
+                flags |= BDRV_REQ_ZERO_WRITE;
+            }
+            break;
+
+        case QCOW2_CLUSTER_ZERO_PLAIN:
+        case QCOW2_CLUSTER_ZERO_ALLOC:
+            flags |= BDRV_REQ_ZERO_WRITE;
+            break;
+
+        case QCOW2_CLUSTER_COMPRESSED:
+            ret = -ENOTSUP;
+            goto out;
+            break;
+
+        case QCOW2_CLUSTER_NORMAL:
+            child = bs->file;
+            if ((cluster_offset & 511) != 0) {
+                ret = -EIO;
+                goto out;
+            }
+            break;
+
+        default:
+            abort();
+        }
+        qemu_co_mutex_unlock(&s->lock);
+        ret = bdrv_co_copy_range_from(child,
+                                      cluster_offset + offset_in_cluster,
+                                      dst, dst_offset,
+                                      cur_bytes, flags);
+        qemu_co_mutex_lock(&s->lock);
+        if (ret < 0) {
+            goto out;
+        }
+
+        bytes -= cur_bytes;
+        src_offset += cur_bytes;
+    }
+    ret = 0;
+
+out:
+    qemu_co_mutex_unlock(&s->lock);
+    return ret;
+}
+
+static int qcow2_co_copy_range_to(BlockDriverState *bs,
+                                  BdrvChild *src, uint64_t src_offset,
+                                  BdrvChild *dst, uint64_t dst_offset,
+                                  uint64_t bytes, BdrvRequestFlags flags)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int offset_in_cluster;
+    int ret;
+    unsigned int cur_bytes; /* number of sectors in current iteration */
+    uint64_t cluster_offset;
+    uint8_t *cluster_data = NULL;
+    QCowL2Meta *l2meta = NULL;
+
+    assert(!bs->encrypted);
+    s->cluster_cache_offset = -1; /* disable compressed cache */
+
+    qemu_co_mutex_lock(&s->lock);
+
+    while (bytes != 0) {
+
+        l2meta = NULL;
+
+        offset_in_cluster = offset_into_cluster(s, dst_offset);
+        cur_bytes = MIN(bytes, INT_MAX);
+
+        /* TODO:
+         * If src->bs == dst->bs, we could simply copy by incrementing
+         * the refcnt, without copying user data.
+         * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
+        ret = qcow2_alloc_cluster_offset(bs, dst_offset, &cur_bytes,
+                                         &cluster_offset, &l2meta);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        assert((cluster_offset & 511) == 0);
+
+        ret = qcow2_pre_write_overlap_check(bs, 0,
+                cluster_offset + offset_in_cluster, cur_bytes);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        qemu_co_mutex_unlock(&s->lock);
+        ret = bdrv_co_copy_range_to(src, src_offset,
+                                    bs->file,
+                                    cluster_offset + offset_in_cluster,
+                                    cur_bytes, flags);
+        qemu_co_mutex_lock(&s->lock);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        while (l2meta != NULL) {
+            QCowL2Meta *next;
+
+            ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
+            if (ret < 0) {
+                goto fail;
+            }
+
+            /* Take the request off the list of running requests */
+            if (l2meta->nb_clusters != 0) {
+                QLIST_REMOVE(l2meta, next_in_flight);
+            }
+
+            qemu_co_queue_restart_all(&l2meta->dependent_requests);
+
+            next = l2meta->next;
+            g_free(l2meta);
+            l2meta = next;
+        }
+
+        bytes -= cur_bytes;
+        dst_offset += cur_bytes;
+    }
+    ret = 0;
+
+fail:
+    qcow2_handle_l2meta(bs, l2meta);
+
+    qemu_co_mutex_unlock(&s->lock);
+
+    qemu_vfree(cluster_data);
+    trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
+
+    return ret;
+}
+
 static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
                           PreallocMode prealloc, Error **errp)
 {
@@ -4515,6 +4681,8 @@ BlockDriver bdrv_qcow2 = {
 
     .bdrv_co_pwrite_zeroes  = qcow2_co_pwrite_zeroes,
     .bdrv_co_pdiscard       = qcow2_co_pdiscard,
+    .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
+    .bdrv_co_copy_range_to  = qcow2_co_copy_range_to,
     .bdrv_truncate          = qcow2_truncate,
     .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed,
     .bdrv_make_empty        = qcow2_make_empty,
-- 
2.14.3

[Qemu-devel] [PATCH v3 4/9] file-posix: Implement bdrv_co_copy_range

[Fam Zheng]

With copy_file_range(2), we can implement the bdrv_co_copy_range
semantics.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/file-posix.c      | 94 +++++++++++++++++++++++++++++++++++++++++++++++--
 include/block/raw-aio.h | 10 ++++--
 2 files changed, 99 insertions(+), 5 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 3794c0007a..138bf28747 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -59,6 +59,7 @@
 #ifdef __linux__
 #include <sys/ioctl.h>
 #include <sys/param.h>
+#include <sys/syscall.h>
 #include <linux/cdrom.h>
 #include <linux/fd.h>
 #include <linux/fs.h>
@@ -185,6 +186,8 @@ typedef struct RawPosixAIOData {
 #define aio_ioctl_cmd   aio_nbytes /* for QEMU_AIO_IOCTL */
     off_t aio_offset;
     int aio_type;
+    int aio_fd2;
+    off_t aio_offset2;
 } RawPosixAIOData;
 
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
@@ -1421,6 +1424,43 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
     return -ENOTSUP;
 }
 
+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)
+{
+#ifdef __NR_copy_file_range
+    return syscall(__NR_copy_file_range, in_fd, in_off, out_fd,
+                   out_off, len, flags);
+#else
+    errno = ENOSYS;
+    return -1;
+#endif
+}
+
+static ssize_t handle_aiocb_copy_range(RawPosixAIOData *aiocb)
+{
+    uint64_t bytes = aiocb->aio_nbytes;
+    off_t in_off = aiocb->aio_offset;
+    off_t out_off = aiocb->aio_offset2;
+
+    while (bytes) {
+        ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off,
+                                      aiocb->aio_fd2, &out_off,
+                                      bytes, 0);
+        if (ret == -EINTR) {
+            continue;
+        }
+        if (ret < 0) {
+            return -errno;
+        }
+        if (!ret) {
+            /* No progress (e.g. when beyond EOF), fall back to buffer I/O. */
+            return -ENOTSUP;
+        }
+        bytes -= ret;
+    }
+    return 0;
+}
+
 static ssize_t handle_aiocb_discard(RawPosixAIOData *aiocb)
 {
     int ret = -EOPNOTSUPP;
@@ -1501,6 +1541,9 @@ static int aio_worker(void *arg)
     case QEMU_AIO_WRITE_ZEROES:
         ret = handle_aiocb_write_zeroes(aiocb);
         break;
+    case QEMU_AIO_COPY_RANGE:
+        ret = handle_aiocb_copy_range(aiocb);
+        break;
     default:
         fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
         ret = -EINVAL;
@@ -1511,9 +1554,10 @@ static int aio_worker(void *arg)
     return ret;
 }
 
-static int paio_submit_co(BlockDriverState *bs, int fd,
-                          int64_t offset, QEMUIOVector *qiov,
-                          int bytes, int type)
+static int paio_submit_co_full(BlockDriverState *bs, int fd,
+                               int64_t offset, int fd2, int64_t offset2,
+                               QEMUIOVector *qiov,
+                               int bytes, int type)
 {
     RawPosixAIOData *acb = g_new(RawPosixAIOData, 1);
     ThreadPool *pool;
@@ -1521,6 +1565,8 @@ static int paio_submit_co(BlockDriverState *bs, int fd,
     acb->bs = bs;
     acb->aio_type = type;
     acb->aio_fildes = fd;
+    acb->aio_fd2 = fd2;
+    acb->aio_offset2 = offset2;
 
     acb->aio_nbytes = bytes;
     acb->aio_offset = offset;
@@ -1536,6 +1582,13 @@ static int paio_submit_co(BlockDriverState *bs, int fd,
     return thread_pool_submit_co(pool, aio_worker, acb);
 }
 
+static inline int paio_submit_co(BlockDriverState *bs, int fd,
+                                 int64_t offset, QEMUIOVector *qiov,
+                                 int bytes, int type)
+{
+    return paio_submit_co_full(bs, fd, offset, -1, 0, qiov, bytes, type);
+}
+
 static BlockAIOCB *paio_submit(BlockDriverState *bs, int fd,
         int64_t offset, QEMUIOVector *qiov, int bytes,
         BlockCompletionFunc *cb, void *opaque, int type)
@@ -2312,6 +2365,35 @@ static void raw_abort_perm_update(BlockDriverState *bs)
     raw_handle_perm_lock(bs, RAW_PL_ABORT, 0, 0, NULL);
 }
 
+static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
+                                  BdrvChild *src, uint64_t src_offset,
+                                  BdrvChild *dst, uint64_t dst_offset,
+                                  uint64_t bytes, BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes, flags);
+}
+
+static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
+                                             BdrvChild *src, uint64_t src_offset,
+                                             BdrvChild *dst, uint64_t dst_offset,
+                                             uint64_t bytes, BdrvRequestFlags flags)
+{
+    BDRVRawState *s = bs->opaque;
+    BDRVRawState *src_s;
+
+    assert(dst->bs == bs);
+    if (src->bs->drv->bdrv_co_copy_range_to != raw_co_copy_range_to) {
+        return -ENOTSUP;
+    }
+
+    src_s = src->opaque;
+    if (fd_open(bs) < 0 || fd_open(bs) < 0) {
+        return -EIO;
+    }
+    return paio_submit_co_full(bs, src_s->fd, src_offset, s->fd, dst_offset,
+                               NULL, bytes, QEMU_AIO_COPY_RANGE);
+}
+
 BlockDriver bdrv_file = {
     .format_name = "file",
     .protocol_name = "file",
@@ -2334,6 +2416,8 @@ BlockDriver bdrv_file = {
     .bdrv_co_pwritev        = raw_co_pwritev,
     .bdrv_aio_flush = raw_aio_flush,
     .bdrv_aio_pdiscard = raw_aio_pdiscard,
+    .bdrv_co_copy_range_from = raw_co_copy_range_from,
+    .bdrv_co_copy_range_to  = raw_co_copy_range_to,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_io_plug = raw_aio_plug,
     .bdrv_io_unplug = raw_aio_unplug,
@@ -2811,6 +2895,10 @@ static BlockDriver bdrv_host_device = {
     .bdrv_co_pwritev        = raw_co_pwritev,
     .bdrv_aio_flush	= raw_aio_flush,
     .bdrv_aio_pdiscard   = hdev_aio_pdiscard,
+    .bdrv_co_copy_range_from = raw_co_copy_range_from,
+    .bdrv_co_copy_range_to  = raw_co_copy_range_to,
+    .bdrv_co_copy_range_from = raw_co_copy_range_from,
+    .bdrv_co_copy_range_to  = raw_co_copy_range_to,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_io_plug = raw_aio_plug,
     .bdrv_io_unplug = raw_aio_unplug,
diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h
index a4cdbbf1b7..324053020b 100644
--- a/include/block/raw-aio.h
+++ b/include/block/raw-aio.h
@@ -25,9 +25,15 @@
 #define QEMU_AIO_FLUSH        0x0008
 #define QEMU_AIO_DISCARD      0x0010
 #define QEMU_AIO_WRITE_ZEROES 0x0020
+#define QEMU_AIO_COPY_RANGE   0x0040
 #define QEMU_AIO_TYPE_MASK \
-        (QEMU_AIO_READ|QEMU_AIO_WRITE|QEMU_AIO_IOCTL|QEMU_AIO_FLUSH| \
-         QEMU_AIO_DISCARD|QEMU_AIO_WRITE_ZEROES)
+        (QEMU_AIO_READ | \
+         QEMU_AIO_WRITE | \
+         QEMU_AIO_IOCTL | \
+         QEMU_AIO_FLUSH | \
+         QEMU_AIO_DISCARD | \
+         QEMU_AIO_WRITE_ZEROES | \
+         QEMU_AIO_COPY_RANGE)
 
 /* AIO flags */
 #define QEMU_AIO_MISALIGNED   0x1000
-- 
2.14.3

[Qemu-devel] [PATCH v3 5/9] iscsi: Query and save device designator when opening

[Fam Zheng]

The device designator data returned in INQUIRY command will be useful to
fill in source/target fields during copy offloading. Do this when
connecting to the target and save the data for later use.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/iscsi.c            | 41 +++++++++++++++++++++++++++++++++++++++++
 include/scsi/constants.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index d19ae0e398..5811ff1d51 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -68,6 +68,7 @@ typedef struct IscsiLun {
     QemuMutex mutex;
     struct scsi_inquiry_logical_block_provisioning lbp;
     struct scsi_inquiry_block_limits bl;
+    struct scsi_inquiry_device_designator *dd;
     unsigned char *zeroblock;
     /* The allocmap tracks which clusters (pages) on the iSCSI target are
      * allocated and which are not. In case a target returns zeros for
@@ -1740,6 +1741,30 @@ static QemuOptsList runtime_opts = {
     },
 };
 
+static void iscsi_save_designator(IscsiLun *lun,
+                                  struct scsi_inquiry_device_identification *inq_di)
+{
+    struct scsi_inquiry_device_designator *desig, *copy = NULL;
+
+    for (desig = inq_di->designators; desig; desig = desig->next) {
+        if (desig->association ||
+            desig->designator_type > SCSI_DESIGNATOR_TYPE_NAA) {
+            continue;
+        }
+        /* NAA works better than T10 vendor ID based designator. */
+        if (!copy || copy->designator_type < desig->designator_type) {
+            copy = desig;
+        }
+    }
+    if (copy) {
+        lun->dd = g_new(struct scsi_inquiry_device_designator, 1);
+        *lun->dd = *copy;
+        lun->dd->next = NULL;
+        lun->dd->designator = g_malloc(copy->designator_length);
+        memcpy(lun->dd->designator, copy->designator, copy->designator_length);
+    }
+}
+
 static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
                       Error **errp)
 {
@@ -1922,6 +1947,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
         struct scsi_task *inq_task;
         struct scsi_inquiry_logical_block_provisioning *inq_lbp;
         struct scsi_inquiry_block_limits *inq_bl;
+        struct scsi_inquiry_device_identification *inq_di;
         switch (inq_vpd->pages[i]) {
         case SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING:
             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
@@ -1947,6 +1973,17 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
                    sizeof(struct scsi_inquiry_block_limits));
             scsi_free_scsi_task(inq_task);
             break;
+        case SCSI_INQUIRY_PAGECODE_DEVICE_IDENTIFICATION:
+            inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
+                                    SCSI_INQUIRY_PAGECODE_DEVICE_IDENTIFICATION,
+                                    (void **) &inq_di, errp);
+            if (inq_task == NULL) {
+                ret = -EINVAL;
+                goto out;
+            }
+            iscsi_save_designator(iscsilun, inq_di);
+            scsi_free_scsi_task(inq_task);
+            break;
         default:
             break;
         }
@@ -2003,6 +2040,10 @@ static void iscsi_close(BlockDriverState *bs)
         iscsi_logout_sync(iscsi);
     }
     iscsi_destroy_context(iscsi);
+    if (iscsilun->dd) {
+        g_free(iscsilun->dd->designator);
+        g_free(iscsilun->dd);
+    }
     g_free(iscsilun->zeroblock);
     iscsi_allocmap_free(iscsilun);
     qemu_mutex_destroy(&iscsilun->mutex);
diff --git a/include/scsi/constants.h b/include/scsi/constants.h
index a141dd71f8..54733b7110 100644
--- a/include/scsi/constants.h
+++ b/include/scsi/constants.h
@@ -311,4 +311,6 @@
 #define MMC_PROFILE_HDDVD_RW_DL         0x005A
 #define MMC_PROFILE_INVALID             0xFFFF
 
+#define IDENT_DESCR_TGT_DESCR 0xE4
+
 #endif
-- 
2.14.3

[Qemu-devel] [PATCH v3 6/9] iscsi: Create and use iscsi_co_wait_for_task

[Fam Zheng]

This loop is repeated a growing number times. Make a helper.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/iscsi.c | 54 +++++++++++++++++-------------------------------------
 1 file changed, 17 insertions(+), 37 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 5811ff1d51..32e755c021 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -556,6 +556,17 @@ static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
                                offset / iscsilun->cluster_size) == size);
 }
 
+static void coroutine_fn iscsi_co_wait_for_task(IscsiTask *iTask,
+                                                IscsiLun *iscsilun)
+{
+    while (!iTask->complete) {
+        iscsi_set_events(iscsilun);
+        qemu_mutex_unlock(&iscsilun->mutex);
+        qemu_coroutine_yield();
+        qemu_mutex_lock(&iscsilun->mutex);
+    }
+}
+
 static int coroutine_fn
 iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
                       QEMUIOVector *iov, int flags)
@@ -617,12 +628,7 @@ retry:
     scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
                           iov->niov);
 #endif
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
+    iscsi_co_wait_for_task(&iTask, iscsilun);
 
     if (iTask.task != NULL) {
         scsi_free_scsi_task(iTask.task);
@@ -693,13 +699,7 @@ retry:
         ret = -ENOMEM;
         goto out_unlock;
     }
-
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
+    iscsi_co_wait_for_task(&iTask, iscsilun);
 
     if (iTask.do_retry) {
         if (iTask.task != NULL) {
@@ -863,13 +863,8 @@ retry:
 #if LIBISCSI_API_VERSION < (20160603)
     scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
 #endif
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
 
+    iscsi_co_wait_for_task(&iTask, iscsilun);
     if (iTask.task != NULL) {
         scsi_free_scsi_task(iTask.task);
         iTask.task = NULL;
@@ -906,12 +901,7 @@ retry:
         return -ENOMEM;
     }
 
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
+    iscsi_co_wait_for_task(&iTask, iscsilun);
 
     if (iTask.task != NULL) {
         scsi_free_scsi_task(iTask.task);
@@ -1143,12 +1133,7 @@ retry:
         goto out_unlock;
     }
 
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
+    iscsi_co_wait_for_task(&iTask, iscsilun);
 
     if (iTask.task != NULL) {
         scsi_free_scsi_task(iTask.task);
@@ -1244,12 +1229,7 @@ retry:
         return -ENOMEM;
     }
 
-    while (!iTask.complete) {
-        iscsi_set_events(iscsilun);
-        qemu_mutex_unlock(&iscsilun->mutex);
-        qemu_coroutine_yield();
-        qemu_mutex_lock(&iscsilun->mutex);
-    }
+    iscsi_co_wait_for_task(&iTask, iscsilun);
 
     if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
         iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
-- 
2.14.3

[Qemu-devel] [PATCH v3 7/9] iscsi: Implement copy offloading

[Fam Zheng]

Issue EXTENDED COPY (LID1) command to implement the copy_range API.

The parameter data construction code is modified from libiscsi's
iscsi-dd.c.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/iscsi.c            | 228 +++++++++++++++++++++++++++++++++++++++++++++++
 include/scsi/constants.h |   3 +
 2 files changed, 231 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index 32e755c021..b736c75db5 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -2205,6 +2205,230 @@ static void coroutine_fn iscsi_co_invalidate_cache(BlockDriverState *bs,
     iscsi_allocmap_invalidate(iscsilun);
 }
 
+static int coroutine_fn iscsi_co_copy_range_from(BlockDriverState *bs,
+                                                 BdrvChild *src,
+                                                 uint64_t src_offset,
+                                                 BdrvChild *dst,
+                                                 uint64_t dst_offset,
+                                                 uint64_t bytes,
+                                                 BdrvRequestFlags flags)
+{
+    return bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes, flags);
+}
+
+static struct scsi_task *iscsi_xcopy_task(int param_len)
+{
+    struct scsi_task *task;
+
+    task = g_new0(struct scsi_task, 1);
+
+    task->cdb[0]     = EXTENDED_COPY;
+    task->cdb[10]    = (param_len >> 24) & 0xFF;
+    task->cdb[11]    = (param_len >> 16) & 0xFF;
+    task->cdb[12]    = (param_len >> 8) & 0xFF;
+    task->cdb[13]    = param_len & 0xFF;
+    task->cdb_size   = 16;
+    task->xfer_dir   = SCSI_XFER_WRITE;
+    task->expxferlen = param_len;
+
+    return task;
+}
+
+static int iscsi_populate_target_desc(unsigned char *desc, IscsiLun *lun)
+{
+    struct scsi_inquiry_device_designator *dd = lun->dd;
+
+    memset(desc, 0, 32);
+    desc[0] = IDENT_DESCR_TGT_DESCR;
+    desc[4] = dd->code_set;
+    desc[5] = (dd->designator_type & 0xF)
+        | ((dd->association & 3) << 4);
+    desc[7] = dd->designator_length;
+    memcpy(desc + 8, dd->designator, dd->designator_length);
+
+    desc[28] = 0;
+    desc[29] = (lun->block_size >> 16) & 0xFF;
+    desc[30] = (lun->block_size >> 8) & 0xFF;
+    desc[31] = lun->block_size & 0xFF;
+
+    return 32;
+}
+
+static int iscsi_xcopy_desc_hdr(uint8_t *hdr, int dc, int cat, int src_index,
+                                int dst_index)
+{
+    int desc_len = 28;
+
+    hdr[0] = 0x02; /* BLK_TO_BLK_SEG_DESCR */
+    hdr[1] = ((dc << 1) | cat) & 0xFF;
+    hdr[2] = (desc_len >> 8) & 0xFF;
+    /* don't account for the first 4 bytes in descriptor header*/
+    hdr[3] = (desc_len - 4 /* SEG_DESC_SRC_INDEX_OFFSET */) & 0xFF;
+    hdr[4] = (src_index >> 8) & 0xFF;
+    hdr[5] = src_index & 0xFF;
+    hdr[6] = (dst_index >> 8) & 0xFF;
+    hdr[7] = dst_index & 0xFF;
+
+    return desc_len;
+}
+
+static int iscsi_xcopy_populate_desc(uint8_t *desc, int dc, int cat,
+                                     int src_index, int dst_index, int num_blks,
+                                     uint64_t src_lba, uint64_t dst_lba)
+{
+    int desc_len = iscsi_xcopy_desc_hdr(desc, dc, cat,
+                                        src_index, dst_index);
+
+    /* The caller should verify the request size */
+    assert(num_blks < 65536);
+    desc[10] = (num_blks >> 8) & 0xFF;
+    desc[11] = num_blks & 0xFF;
+    desc[12] = (src_lba >> 56) & 0xFF;
+    desc[13] = (src_lba >> 48) & 0xFF;
+    desc[14] = (src_lba >> 40) & 0xFF;
+    desc[15] = (src_lba >> 32) & 0xFF;
+    desc[16] = (src_lba >> 24) & 0xFF;
+    desc[17] = (src_lba >> 16) & 0xFF;
+    desc[18] = (src_lba >> 8) & 0xFF;
+    desc[19] = src_lba & 0xFF;
+    desc[20] = (dst_lba >> 56) & 0xFF;
+    desc[21] = (dst_lba >> 48) & 0xFF;
+    desc[22] = (dst_lba >> 40) & 0xFF;
+    desc[23] = (dst_lba >> 32) & 0xFF;
+    desc[24] = (dst_lba >> 24) & 0xFF;
+    desc[25] = (dst_lba >> 16) & 0xFF;
+    desc[26] = (dst_lba >> 8) & 0xFF;
+    desc[27] = dst_lba & 0xFF;
+
+    return desc_len;
+}
+
+static void iscsi_xcopy_populate_header(unsigned char *buf, int list_id, int str,
+                                        int list_id_usage, int prio,
+                                        int tgt_desc_len,
+                                        int seg_desc_len, int inline_data_len)
+{
+    buf[0] = list_id;
+    buf[1] = ((str & 1) << 5) | ((list_id_usage & 3) << 3) | (prio & 7);
+    buf[2] = (tgt_desc_len >> 8) & 0xFF;
+    buf[3] = tgt_desc_len & 0xFF;
+    buf[8] = (seg_desc_len >> 24) & 0xFF;
+    buf[9] = (seg_desc_len >> 16) & 0xFF;
+    buf[10] = (seg_desc_len >> 8) & 0xFF;
+    buf[11] = seg_desc_len & 0xFF;
+    buf[12] = (inline_data_len >> 24) & 0xFF;
+    buf[13] = (inline_data_len >> 16) & 0xFF;
+    buf[14] = (inline_data_len >> 8) & 0xFF;
+    buf[15] = inline_data_len & 0xFF;
+}
+
+static void iscsi_xcopy_data(struct iscsi_data *data,
+                             IscsiLun *src, int64_t src_lba,
+                             IscsiLun *dst, int64_t dst_lba,
+                             uint16_t num_blocks)
+{
+    uint8_t *buf;
+    const int src_offset = XCOPY_DESC_OFFSET;
+    const int dst_offset = XCOPY_DESC_OFFSET + IDENT_DESCR_TGT_DESCR_SIZE;
+    const int seg_offset = dst_offset + IDENT_DESCR_TGT_DESCR_SIZE;
+
+    data->size = XCOPY_DESC_OFFSET +
+                 IDENT_DESCR_TGT_DESCR_SIZE * 2 +
+                 XCOPY_BLK2BLK_SEG_DESC_SIZE;
+    data->data = g_malloc0(data->size);
+    buf = data->data;
+
+    /* Initialise the parameter list header */
+    iscsi_xcopy_populate_header(buf, 1, 0, 2 /* LIST_ID_USAGE_DISCARD */,
+                                0, 2 * IDENT_DESCR_TGT_DESCR_SIZE,
+                                XCOPY_BLK2BLK_SEG_DESC_SIZE,
+                                0);
+
+    /* Initialise CSCD list with one src + one dst descriptor */
+    iscsi_populate_target_desc(&buf[src_offset], src);
+    iscsi_populate_target_desc(&buf[dst_offset], dst);
+
+    /* Initialise one segment descriptor */
+    iscsi_xcopy_populate_desc(&buf[seg_offset], 0, 0, 0, 1, num_blocks,
+                              src_lba, dst_lba);
+}
+
+static int coroutine_fn iscsi_co_copy_range_to(BlockDriverState *bs,
+                                               BdrvChild *src,
+                                               uint64_t src_offset,
+                                               BdrvChild *dst,
+                                               uint64_t dst_offset,
+                                               uint64_t bytes,
+                                               BdrvRequestFlags flags)
+{
+    IscsiLun *dst_lun = dst->bs->opaque;
+    IscsiLun *src_lun;
+    struct IscsiTask iscsi_task;
+    struct iscsi_data data;
+    int r = 0;
+    int block_size;
+
+    if (src->bs->drv->bdrv_co_copy_range_to != iscsi_co_copy_range_to) {
+        return -ENOTSUP;
+    }
+    src_lun = src->bs->opaque;
+
+    if (!src_lun->dd || !dst_lun->dd) {
+        return -ENOTSUP;
+    }
+    if (!is_byte_request_lun_aligned(dst_offset, bytes, dst_lun)) {
+        return -ENOTSUP;
+    }
+    if (!is_byte_request_lun_aligned(src_offset, bytes, src_lun)) {
+        return -ENOTSUP;
+    }
+    if (dst_lun->block_size != src_lun->block_size ||
+        !dst_lun->block_size) {
+        return -ENOTSUP;
+    }
+
+    block_size = dst_lun->block_size;
+    if (bytes / block_size > 65535) {
+        return -ENOTSUP;
+    }
+
+    iscsi_xcopy_data(&data,
+                     src_lun, src_offset / block_size,
+                     dst_lun, dst_offset / block_size,
+                     bytes / block_size);
+
+    iscsi_co_init_iscsitask(dst_lun, &iscsi_task);
+
+    qemu_mutex_lock(&dst_lun->mutex);
+    iscsi_task.task = iscsi_xcopy_task(data.size);
+retry:
+    if (iscsi_scsi_command_async(dst_lun->iscsi, dst_lun->lun,
+                                 iscsi_task.task, iscsi_co_generic_cb,
+                                 &data,
+                                 &iscsi_task) != 0) {
+        r = -EIO;
+        goto out_unlock;
+    }
+
+    iscsi_co_wait_for_task(&iscsi_task, dst_lun);
+
+    if (iscsi_task.do_retry) {
+        iscsi_task.complete = 0;
+        goto retry;
+    }
+
+    if (iscsi_task.status != SCSI_STATUS_GOOD) {
+        r = iscsi_task.err_code;
+        goto out_unlock;
+    }
+
+out_unlock:
+    g_free(iscsi_task.task);
+    qemu_mutex_unlock(&dst_lun->mutex);
+    g_free(iscsi_task.err_str);
+    return r;
+}
+
 static QemuOptsList iscsi_create_opts = {
     .name = "iscsi-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
@@ -2239,6 +2463,8 @@ static BlockDriver bdrv_iscsi = {
 
     .bdrv_co_block_status  = iscsi_co_block_status,
     .bdrv_co_pdiscard      = iscsi_co_pdiscard,
+    .bdrv_co_copy_range_from = iscsi_co_copy_range_from,
+    .bdrv_co_copy_range_to  = iscsi_co_copy_range_to,
     .bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
     .bdrv_co_readv         = iscsi_co_readv,
     .bdrv_co_writev_flags  = iscsi_co_writev_flags,
@@ -2274,6 +2500,8 @@ static BlockDriver bdrv_iser = {
 
     .bdrv_co_block_status  = iscsi_co_block_status,
     .bdrv_co_pdiscard      = iscsi_co_pdiscard,
+    .bdrv_co_copy_range_from = iscsi_co_copy_range_from,
+    .bdrv_co_copy_range_to  = iscsi_co_copy_range_to,
     .bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
     .bdrv_co_readv         = iscsi_co_readv,
     .bdrv_co_writev_flags  = iscsi_co_writev_flags,
diff --git a/include/scsi/constants.h b/include/scsi/constants.h
index 54733b7110..b53ff8adcb 100644
--- a/include/scsi/constants.h
+++ b/include/scsi/constants.h
@@ -311,6 +311,9 @@
 #define MMC_PROFILE_HDDVD_RW_DL         0x005A
 #define MMC_PROFILE_INVALID             0xFFFF
 
+#define XCOPY_DESC_OFFSET 16
 #define IDENT_DESCR_TGT_DESCR 0xE4
+#define IDENT_DESCR_TGT_DESCR_SIZE 32
+#define XCOPY_BLK2BLK_SEG_DESC_SIZE 28
 
 #endif
-- 
2.14.3

[Qemu-devel] [PATCH v3 8/9] block-backend: Add blk_co_copy_range

[Fam Zheng]

It's a BlockBackend wrapper of the BDS interface.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/block-backend.c          | 18 ++++++++++++++++++
 include/sysemu/block-backend.h |  4 ++++
 2 files changed, 22 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 681b240b12..5562ec4238 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -2217,3 +2217,21 @@ void blk_unregister_buf(BlockBackend *blk, void *host)
 {
     bdrv_unregister_buf(blk_bs(blk), host);
 }
+
+int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
+                                   BlockBackend *blk_out, int64_t off_out,
+                                   int bytes, BdrvRequestFlags flags)
+{
+    int r;
+    r = blk_check_byte_request(blk_in, off_in, bytes);
+    if (r) {
+        return r;
+    }
+    r = blk_check_byte_request(blk_out, off_out, bytes);
+    if (r) {
+        return r;
+    }
+    return bdrv_co_copy_range(blk_in->root, off_in,
+                              blk_out->root, off_out,
+                              bytes, flags);
+}
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 92ab624fac..6f043b6b51 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -232,4 +232,8 @@ void blk_set_force_allow_inactivate(BlockBackend *blk);
 void blk_register_buf(BlockBackend *blk, void *host, size_t size);
 void blk_unregister_buf(BlockBackend *blk, void *host);
 
+int blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
+                      BlockBackend *blk_out, int64_t off_out,
+                      int bytes, BdrvRequestFlags flags);
+
 #endif
-- 
2.14.3

[Qemu-devel] [PATCH v3 9/9] qemu-img: Convert with copy offloading

[Fam Zheng]

The new blk_co_copy_range interface offers a more efficient way in the
case of network based storage. Make use of it to allow faster convert
operation.

Since copy offloading cannot do zero detection ('-S') and compression
(-c), only try it when these options are not used.

Update 178.out.qcow2 as we are now a little more efficient on the actual
file size.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 qemu-img.c                       | 50 ++++++++++++++++++++++++++++++++++++++--
 tests/qemu-iotests/178.out.qcow2 |  8 +++----
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index ea62d2d61e..9c3678ebf0 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1544,6 +1544,7 @@ typedef struct ImgConvertState {
     bool compressed;
     bool target_has_backing;
     bool wr_in_order;
+    bool copy_range;
     int min_sparse;
     size_t cluster_sectors;
     size_t buf_sectors;
@@ -1737,6 +1738,37 @@ static int coroutine_fn convert_co_write(ImgConvertState *s, int64_t sector_num,
     return 0;
 }
 
+static int coroutine_fn convert_co_copy_range(ImgConvertState *s, int64_t sector_num,
+                                              int nb_sectors)
+{
+    int n, ret;
+
+    while (nb_sectors > 0) {
+        BlockBackend *blk;
+        int src_cur;
+        int64_t bs_sectors, src_cur_offset;
+        int64_t offset;
+
+        convert_select_part(s, sector_num, &src_cur, &src_cur_offset);
+        offset = (sector_num - src_cur_offset) << BDRV_SECTOR_BITS;
+        blk = s->src[src_cur];
+        bs_sectors = s->src_sectors[src_cur];
+
+        n = MIN(nb_sectors, bs_sectors - (sector_num - src_cur_offset));
+
+        ret = blk_co_copy_range(blk, offset, s->target,
+                                sector_num << BDRV_SECTOR_BITS,
+                                n << BDRV_SECTOR_BITS, 0);
+        if (ret < 0) {
+            return ret;
+        }
+
+        sector_num += n;
+        nb_sectors -= n;
+    }
+    return 0;
+}
+
 static void coroutine_fn convert_co_do_copy(void *opaque)
 {
     ImgConvertState *s = opaque;
@@ -1759,6 +1791,7 @@ static void coroutine_fn convert_co_do_copy(void *opaque)
         int n;
         int64_t sector_num;
         enum ImgConvertBlockStatus status;
+        bool copy_range;
 
         qemu_co_mutex_lock(&s->lock);
         if (s->ret != -EINPROGRESS || s->sector_num >= s->total_sectors) {
@@ -1788,7 +1821,9 @@ static void coroutine_fn convert_co_do_copy(void *opaque)
                                         s->allocated_sectors, 0);
         }
 
-        if (status == BLK_DATA) {
+retry:
+        copy_range = s->copy_range && s->status == BLK_DATA;
+        if (status == BLK_DATA && !copy_range) {
             ret = convert_co_read(s, sector_num, n, buf);
             if (ret < 0) {
                 error_report("error while reading sector %" PRId64
@@ -1810,7 +1845,15 @@ static void coroutine_fn convert_co_do_copy(void *opaque)
         }
 
         if (s->ret == -EINPROGRESS) {
-            ret = convert_co_write(s, sector_num, n, buf, status);
+            if (copy_range) {
+                ret = convert_co_copy_range(s, sector_num, n);
+                if (ret) {
+                    s->copy_range = false;
+                    goto retry;
+                }
+            } else {
+                ret = convert_co_write(s, sector_num, n, buf, status);
+            }
             if (ret < 0) {
                 error_report("error while writing sector %" PRId64
                              ": %s", sector_num, strerror(-ret));
@@ -1933,6 +1976,7 @@ static int img_convert(int argc, char **argv)
     ImgConvertState s = (ImgConvertState) {
         /* Need at least 4k of zeros for sparse detection */
         .min_sparse         = 8,
+        .copy_range         = true,
         .buf_sectors        = IO_BUF_SIZE / BDRV_SECTOR_SIZE,
         .wr_in_order        = true,
         .num_coroutines     = 8,
@@ -1973,6 +2017,7 @@ static int img_convert(int argc, char **argv)
             break;
         case 'c':
             s.compressed = true;
+            s.copy_range = false;
             break;
         case 'o':
             if (!is_valid_option_list(optarg)) {
@@ -2014,6 +2059,7 @@ static int img_convert(int argc, char **argv)
             }
 
             s.min_sparse = sval / BDRV_SECTOR_SIZE;
+            s.copy_range = false;
             break;
         }
         case 'p':
diff --git a/tests/qemu-iotests/178.out.qcow2 b/tests/qemu-iotests/178.out.qcow2
index d42d4a4597..3e72893451 100644
--- a/tests/qemu-iotests/178.out.qcow2
+++ b/tests/qemu-iotests/178.out.qcow2
@@ -54,7 +54,7 @@ wrote 64512/64512 bytes at offset 134217728
 required size: 589824
 fully allocated size: 1074135040
 
-converted image file size in bytes: 524288
+converted image file size in bytes: 523264
 
 == qcow2 input image with internal snapshot (human) ==
 
@@ -107,7 +107,7 @@ wrote 64512/64512 bytes at offset 134217728
 required size: 589824
 fully allocated size: 1074135040
 
-converted image file size in bytes: 524288
+converted image file size in bytes: 523264
 
 == raw input image and a backing file (human) ==
 
@@ -187,7 +187,7 @@ wrote 64512/64512 bytes at offset 134217728
     "fully-allocated": 1074135040
 }
 
-converted image file size in bytes: 524288
+converted image file size in bytes: 523264
 
 == qcow2 input image with internal snapshot (json) ==
 
@@ -254,7 +254,7 @@ wrote 64512/64512 bytes at offset 134217728
     "fully-allocated": 1074135040
 }
 
-converted image file size in bytes: 524288
+converted image file size in bytes: 523264
 
 == raw input image and a backing file (json) ==
 
-- 
2.14.3

Re: [Qemu-devel] [PATCH v3 2/9] raw: Implement copy offloading

[Eric Blake]

On 05/09/2018 09:58 AM, Fam Zheng wrote:
> Just pass down to ->file.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   block/raw-format.c | 20 ++++++++++++++++++++
>   1 file changed, 20 insertions(+)
> 
> diff --git a/block/raw-format.c b/block/raw-format.c
> index a378547c99..febddf00c0 100644
> --- a/block/raw-format.c
> +++ b/block/raw-format.c
> @@ -482,6 +482,24 @@ static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
>       return bdrv_probe_geometry(bs->file->bs, geo);
>   }
>   
> +static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
> +                                               BdrvChild *src, uint64_t src_offset,
> +                                               BdrvChild *dst, uint64_t dst_offset,
> +                                               uint64_t bytes, BdrvRequestFlags flags)
> +{
> +    return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
> +                                   bytes, flags);

Bug - this fails to take into account s->offset, which occurs when 
opening a raw format protocol over a subset of the overall format protocol.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v3 6/9] iscsi: Create and use iscsi_co_wait_for_task

[Eric Blake]

On 05/09/2018 09:58 AM, Fam Zheng wrote:
> This loop is repeated a growing number times. Make a helper.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>   block/iscsi.c | 54 +++++++++++++++++-------------------------------------
>   1 file changed, 17 insertions(+), 37 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v3 1/9] block: Introduce API for copy offloading

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 1854 bytes --]

On Wed, May 09, 2018 at 10:58:07PM +0800, Fam Zheng wrote:

Please include a commit description:

  Introduce the bdrv_co_copy_range() API for copy offloading.  Block
  drivers implementing this API support efficient copy operations that
  avoid reading each block from the source device and writing it to the
  destination devices.  Examples of copy offload primitives are SCSI
  EXTENDED COPY and Linux copy_file_range(2).

This explains the purpose of the new API.

> +/* Copy range from @bs to @dst. */

There is no @bs argument, I guess it should be @src.

What about the return value?

What about the flags?

You don't need to duplicate this information, just reference
BlockDriver.bdrv_co_copy_range_from() if you want.

> +int bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
> +                            BdrvChild *dst, uint64_t dst_offset,
> +                            uint64_t bytes, BdrvRequestFlags flags)
> +{
> +    return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset,
> +                                       bytes, flags, true);
> +}
> +
> +/* Copy range from @src to @bs. Should only be called by block drivers when @bs
> + * is the leaf. */

Same here.

> diff --git a/include/block/block.h b/include/block/block.h
> index cdec3639a3..72ac011b2b 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -604,4 +604,8 @@ bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
>   */
>  void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
>  void bdrv_unregister_buf(BlockDriverState *bs, void *host);
> +
> +int bdrv_co_copy_range(BdrvChild *bs, uint64_t offset,
> +                       BdrvChild *src, uint64_t src_offset,
> +                       uint64_t bytes, BdrvRequestFlags flags);

This is the public API.  It's missing a doc comment.

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Re: [Qemu-devel] [PATCH v3 4/9] file-posix: Implement bdrv_co_copy_range

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 1044 bytes --]

On Wed, May 09, 2018 at 10:58:10PM +0800, Fam Zheng wrote:
> +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)
> +{
> +#ifdef __NR_copy_file_range
> +    return syscall(__NR_copy_file_range, in_fd, in_off, out_fd,
> +                   out_off, len, flags);
> +#else
> +    errno = ENOSYS;
> +    return -1;
> +#endif
> +}
> +
> +static ssize_t handle_aiocb_copy_range(RawPosixAIOData *aiocb)
> +{
> +    uint64_t bytes = aiocb->aio_nbytes;
> +    off_t in_off = aiocb->aio_offset;
> +    off_t out_off = aiocb->aio_offset2;
> +
> +    while (bytes) {
> +        ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off,
> +                                      aiocb->aio_fd2, &out_off,
> +                                      bytes, 0);
> +        if (ret == -EINTR) {
> +            continue;
> +        }
> +        if (ret < 0) {
> +            return -errno;

Convert ENOSYS to ENOTSUP?

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 5/9] iscsi: Query and save device designator when opening

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 528 bytes --]

On Wed, May 09, 2018 at 10:58:11PM +0800, Fam Zheng wrote:
> The device designator data returned in INQUIRY command will be useful to
> fill in source/target fields during copy offloading. Do this when
> connecting to the target and save the data for later use.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/iscsi.c            | 41 +++++++++++++++++++++++++++++++++++++++++
>  include/scsi/constants.h |  2 ++
>  2 files changed, 43 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 6/9] iscsi: Create and use iscsi_co_wait_for_task

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 367 bytes --]

On Wed, May 09, 2018 at 10:58:12PM +0800, Fam Zheng wrote:
> This loop is repeated a growing number times. Make a helper.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/iscsi.c | 54 +++++++++++++++++-------------------------------------
>  1 file changed, 17 insertions(+), 37 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 7/9] iscsi: Implement copy offloading

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 1199 bytes --]

On Wed, May 09, 2018 at 10:58:13PM +0800, Fam Zheng wrote:
> +static int iscsi_populate_target_desc(unsigned char *desc, IscsiLun *lun)

The return values of these iscsi_populate_*() functions are unused and
don't make sense since the caller must already know the size ahead of
time.  I suggest removing them to simplify the code.

> +{
> +    struct scsi_inquiry_device_designator *dd = lun->dd;
> +
> +    memset(desc, 0, 32);
> +    desc[0] = IDENT_DESCR_TGT_DESCR;
> +    desc[4] = dd->code_set;
> +    desc[5] = (dd->designator_type & 0xF)
> +        | ((dd->association & 3) << 4);
> +    desc[7] = dd->designator_length;
> +    memcpy(desc + 8, dd->designator, dd->designator_length);
> +
> +    desc[28] = 0;
> +    desc[29] = (lun->block_size >> 16) & 0xFF;
> +    desc[30] = (lun->block_size >> 8) & 0xFF;
> +    desc[31] = lun->block_size & 0xFF;
> +
> +    return 32;
> +}
> +
> +static int iscsi_xcopy_desc_hdr(uint8_t *hdr, int dc, int cat, int src_index,
> +                                int dst_index)
> +{
> +    int desc_len = 28;

s/desc_len/XCOPY_BLK2BLK_SEG_DESC_SIZE/ ?

Then the 28 constant doesn't need to be duplicated.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 8/9] block-backend: Add blk_co_copy_range

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 355 bytes --]

On Wed, May 09, 2018 at 10:58:14PM +0800, Fam Zheng wrote:
> It's a BlockBackend wrapper of the BDS interface.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/block-backend.c          | 18 ++++++++++++++++++
>  include/sysemu/block-backend.h |  4 ++++
>  2 files changed, 22 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 9/9] qemu-img: Convert with copy offloading

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 744 bytes --]

On Wed, May 09, 2018 at 10:58:15PM +0800, Fam Zheng wrote:
> The new blk_co_copy_range interface offers a more efficient way in the
> case of network based storage. Make use of it to allow faster convert
> operation.
> 
> Since copy offloading cannot do zero detection ('-S') and compression
> (-c), only try it when these options are not used.
> 
> Update 178.out.qcow2 as we are now a little more efficient on the actual
> file size.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  qemu-img.c                       | 50 ++++++++++++++++++++++++++++++++++++++--
>  tests/qemu-iotests/178.out.qcow2 |  8 +++----
>  2 files changed, 52 insertions(+), 6 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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Re: [Qemu-devel] [PATCH v3 3/9] qcow2: Implement copy offloading

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 1334 bytes --]

On Wed, May 09, 2018 at 10:58:09PM +0800, Fam Zheng wrote:
> +static int qcow2_co_copy_range_from(BlockDriverState *bs,
> +                                    BdrvChild *src, uint64_t src_offset,
> +                                    BdrvChild *dst, uint64_t dst_offset,
> +                                    uint64_t bytes, BdrvRequestFlags flags)
> +{
> +    BDRVQcow2State *s = bs->opaque;
> +    int offset_in_cluster;
> +    int ret;
> +    unsigned int cur_bytes; /* number of bytes in current iteration */
> +    uint64_t cluster_offset = 0;
> +    BdrvChild *child = NULL;
> +
> +    assert(!bs->encrypted);
> +    qemu_co_mutex_lock(&s->lock);
> +
> +    while (bytes != 0) {
> +
> +        /* prepare next request */
> +        cur_bytes = MIN(bytes, INT_MAX);
> +
> +        ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, &cluster_offset);
> +        if (ret < 0) {
> +            goto out;
> +        }
> +
> +        offset_in_cluster = offset_into_cluster(s, src_offset);
> +
> +        switch (ret) {
> +        case QCOW2_CLUSTER_UNALLOCATED:
> +            if (bs->backing) {
> +                child = bs->backing;
> +            } else {
> +                flags |= BDRV_REQ_ZERO_WRITE;
> +            }
> +            break;

Do we need a special case if the backing file is shorter than this
image?

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Re: [Qemu-devel] [PATCH v3 3/9] qcow2: Implement copy offloading

[Fam Zheng]

On Thu, 05/10 10:25, Stefan Hajnoczi wrote:
> On Wed, May 09, 2018 at 10:58:09PM +0800, Fam Zheng wrote:
> > +static int qcow2_co_copy_range_from(BlockDriverState *bs,
> > +                                    BdrvChild *src, uint64_t src_offset,
> > +                                    BdrvChild *dst, uint64_t dst_offset,
> > +                                    uint64_t bytes, BdrvRequestFlags flags)
> > +{
> > +    BDRVQcow2State *s = bs->opaque;
> > +    int offset_in_cluster;
> > +    int ret;
> > +    unsigned int cur_bytes; /* number of bytes in current iteration */
> > +    uint64_t cluster_offset = 0;
> > +    BdrvChild *child = NULL;
> > +
> > +    assert(!bs->encrypted);
> > +    qemu_co_mutex_lock(&s->lock);
> > +
> > +    while (bytes != 0) {
> > +
> > +        /* prepare next request */
> > +        cur_bytes = MIN(bytes, INT_MAX);
> > +
> > +        ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, &cluster_offset);
> > +        if (ret < 0) {
> > +            goto out;
> > +        }
> > +
> > +        offset_in_cluster = offset_into_cluster(s, src_offset);
> > +
> > +        switch (ret) {
> > +        case QCOW2_CLUSTER_UNALLOCATED:
> > +            if (bs->backing) {
> > +                child = bs->backing;
> > +            } else {
> > +                flags |= BDRV_REQ_ZERO_WRITE;
> > +            }
> > +            break;
> 
> Do we need a special case if the backing file is shorter than this
> image?

Yes, we should take the BDRV_REQ_ZERO_WRITE path if the range is fully beyond
EOF, otherwise clip cur_bytes at the backing image offset.

Fam

Re: [Qemu-devel] [PATCH v3 2/9] raw: Implement copy offloading

[Fam Zheng]

On Wed, 05/09 10:17, Eric Blake wrote:
> On 05/09/2018 09:58 AM, Fam Zheng wrote:
> > Just pass down to ->file.
> > 
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >   block/raw-format.c | 20 ++++++++++++++++++++
> >   1 file changed, 20 insertions(+)
> > 
> > diff --git a/block/raw-format.c b/block/raw-format.c
> > index a378547c99..febddf00c0 100644
> > --- a/block/raw-format.c
> > +++ b/block/raw-format.c
> > @@ -482,6 +482,24 @@ static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
> >       return bdrv_probe_geometry(bs->file->bs, geo);
> >   }
> > +static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
> > +                                               BdrvChild *src, uint64_t src_offset,
> > +                                               BdrvChild *dst, uint64_t dst_offset,
> > +                                               uint64_t bytes, BdrvRequestFlags flags)
> > +{
> > +    return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
> > +                                   bytes, flags);
> 
> Bug - this fails to take into account s->offset, which occurs when opening a
> raw format protocol over a subset of the overall format protocol.

Good catch. I'll fix it in v4. Thanks.

Fam

Re: [Qemu-devel] [PATCH v3 4/9] file-posix: Implement bdrv_co_copy_range

[Fam Zheng]

On Thu, 05/10 09:50, Stefan Hajnoczi wrote:
> On Wed, May 09, 2018 at 10:58:10PM +0800, Fam Zheng wrote:
> > +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)
> > +{
> > +#ifdef __NR_copy_file_range
> > +    return syscall(__NR_copy_file_range, in_fd, in_off, out_fd,
> > +                   out_off, len, flags);
> > +#else
> > +    errno = ENOSYS;
> > +    return -1;
> > +#endif
> > +}
> > +
> > +static ssize_t handle_aiocb_copy_range(RawPosixAIOData *aiocb)
> > +{
> > +    uint64_t bytes = aiocb->aio_nbytes;
> > +    off_t in_off = aiocb->aio_offset;
> > +    off_t out_off = aiocb->aio_offset2;
> > +
> > +    while (bytes) {
> > +        ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off,
> > +                                      aiocb->aio_fd2, &out_off,
> > +                                      bytes, 0);
> > +        if (ret == -EINTR) {
> > +            continue;
> > +        }
> > +        if (ret < 0) {
> > +            return -errno;
> 
> Convert ENOSYS to ENOTSUP?

Sounds good.