Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Switch AIO/callback based block drivers to a byte-based interface
- Block jobs: Expose error string via query-block-jobs
- Block job cleanups and fixes
- hmp: Allow using a qdev id in block_set_io_throttle

# gpg: Signature made Tue 15 May 2018 16:33:10 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (37 commits)
  iotests: Add test for -U/force-share conflicts
  qemu-img: Use only string options in img_open_opts
  qemu-io: Use purely string blockdev options
  block: Document BDRV_REQ_WRITE_UNCHANGED support
  qemu-img: Check post-truncation size
  iotests: Add test for COR across nodes
  iotests: Copy 197 for COR filter driver
  iotests: Clean up wrap image in 197
  block: Support BDRV_REQ_WRITE_UNCHANGED in filters
  block/quorum: Support BDRV_REQ_WRITE_UNCHANGED
  block: Set BDRV_REQ_WRITE_UNCHANGED for COR writes
  block: Add BDRV_REQ_WRITE_UNCHANGED flag
  block: BLK_PERM_WRITE includes ..._UNCHANGED
  block: Add COR filter driver
  iotests: Skip 181 and 201 without userfaultfd
  iotests: Add failure matching to common.qemu
  docs: Document the new default sizes of the qcow2 caches
  qcow2: Give the refcount cache the minimum possible size by default
  specs/qcow2: Clarify that compressed clusters have the COPIED bit reset
  Fix error message about compressed clusters with OFLAG_COPIED
  ...

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

1 files changed, 173 insertions, 0 deletions

diff --git a/block/copy-on-read.c b/block/copy-on-read.c
new file mode 100644
index 0000000000..6a97208888
--- /dev/null
+++ b/block/copy-on-read.c
@@ -0,0 +1,173 @@
+/*
+ * Copy-on-read filter block driver
+ *
+ * Copyright (c) 2018 Red Hat, Inc.
+ *
+ * Author:
+ *   Max Reitz <mreitz@redhat.com>
+ *
+ * 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 or
+ * (at your option) version 3 of the License.
+ *
+ * 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "block/block_int.h"
+
+
+static int cor_open(BlockDriverState *bs, QDict *options, int flags,
+                    Error **errp)
+{
+    bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false,
+                               errp);
+    if (!bs->file) {
+        return -EINVAL;
+    }
+
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
+                                (BDRV_REQ_FUA &
+                                    bs->file->bs->supported_write_flags);
+
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
+                               ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+                                    bs->file->bs->supported_zero_flags);
+
+    return 0;
+}
+
+
+static void cor_close(BlockDriverState *bs)
+{
+}
+
+
+#define PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
+                          | BLK_PERM_WRITE \
+                          | BLK_PERM_RESIZE)
+#define PERM_UNCHANGED (BLK_PERM_ALL & ~PERM_PASSTHROUGH)
+
+static void cor_child_perm(BlockDriverState *bs, BdrvChild *c,
+                           const BdrvChildRole *role,
+                           BlockReopenQueue *reopen_queue,
+                           uint64_t perm, uint64_t shared,
+                           uint64_t *nperm, uint64_t *nshared)
+{
+    if (c == NULL) {
+        *nperm = (perm & PERM_PASSTHROUGH) | BLK_PERM_WRITE_UNCHANGED;
+        *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
+        return;
+    }
+
+    *nperm = (perm & PERM_PASSTHROUGH) |
+             (c->perm & PERM_UNCHANGED);
+    *nshared = (shared & PERM_PASSTHROUGH) |
+               (c->shared_perm & PERM_UNCHANGED);
+}
+
+
+static int64_t cor_getlength(BlockDriverState *bs)
+{
+    return bdrv_getlength(bs->file->bs);
+}
+
+
+static int cor_truncate(BlockDriverState *bs, int64_t offset,
+                        PreallocMode prealloc, Error **errp)
+{
+    return bdrv_truncate(bs->file, offset, prealloc, errp);
+}
+
+
+static int coroutine_fn cor_co_preadv(BlockDriverState *bs,
+                                      uint64_t offset, uint64_t bytes,
+                                      QEMUIOVector *qiov, int flags)
+{
+    return bdrv_co_preadv(bs->file, offset, bytes, qiov,
+                          flags | BDRV_REQ_COPY_ON_READ);
+}
+
+
+static int coroutine_fn cor_co_pwritev(BlockDriverState *bs,
+                                       uint64_t offset, uint64_t bytes,
+                                       QEMUIOVector *qiov, int flags)
+{
+
+    return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
+}
+
+
+static int coroutine_fn cor_co_pwrite_zeroes(BlockDriverState *bs,
+                                             int64_t offset, int bytes,
+                                             BdrvRequestFlags flags)
+{
+    return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
+}
+
+
+static int coroutine_fn cor_co_pdiscard(BlockDriverState *bs,
+                                        int64_t offset, int bytes)
+{
+    return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
+}
+
+
+static void cor_eject(BlockDriverState *bs, bool eject_flag)
+{
+    bdrv_eject(bs->file->bs, eject_flag);
+}
+
+
+static void cor_lock_medium(BlockDriverState *bs, bool locked)
+{
+    bdrv_lock_medium(bs->file->bs, locked);
+}
+
+
+static bool cor_recurse_is_first_non_filter(BlockDriverState *bs,
+                                            BlockDriverState *candidate)
+{
+    return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
+}
+
+
+BlockDriver bdrv_copy_on_read = {
+    .format_name                        = "copy-on-read",
+
+    .bdrv_open                          = cor_open,
+    .bdrv_close                         = cor_close,
+    .bdrv_child_perm                    = cor_child_perm,
+
+    .bdrv_getlength                     = cor_getlength,
+    .bdrv_truncate                      = cor_truncate,
+
+    .bdrv_co_preadv                     = cor_co_preadv,
+    .bdrv_co_pwritev                    = cor_co_pwritev,
+    .bdrv_co_pwrite_zeroes              = cor_co_pwrite_zeroes,
+    .bdrv_co_pdiscard                   = cor_co_pdiscard,
+
+    .bdrv_eject                         = cor_eject,
+    .bdrv_lock_medium                   = cor_lock_medium,
+
+    .bdrv_co_block_status               = bdrv_co_block_status_from_file,
+
+    .bdrv_recurse_is_first_non_filter   = cor_recurse_is_first_non_filter,
+
+    .has_variable_length                = true,
+    .is_filter                          = true,
+};
+
+static void bdrv_copy_on_read_init(void)
+{
+    bdrv_register(&bdrv_copy_on_read);
+}
+
+block_init(bdrv_copy_on_read_init);