Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-07-06' into staging

Block patches for 5.1:
- LUKS keyslot amendment
  (+ patches to make the iotests pass on non-Linux systems, and to keep
     the tests passing for qcow v1, and to skip LUKS tests (including
     qcow2 LUKS) when the built qemu does not support it)
- Refactoring in the block layer: Drop the basically unnecessary
  unallocated_blocks_are_zero field from BlockDriverInfo
- Fix qcow2 preallocation when the image size is not a multiple of the
  cluster size
- Fix in block-copy code

# gpg: Signature made Mon 06 Jul 2020 11:02:53 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-07-06: (31 commits)
  qed: Simplify backing reads
  block: drop unallocated_blocks_are_zero
  block/vhdx: drop unallocated_blocks_are_zero
  block/file-posix: drop unallocated_blocks_are_zero
  block/iscsi: drop unallocated_blocks_are_zero
  block/crypto: drop unallocated_blocks_are_zero
  block/vpc: return ZERO block-status when appropriate
  block/vdi: return ZERO block-status when appropriate
  block: inline bdrv_unallocated_blocks_are_zero()
  qemu-img: convert: don't use unallocated_blocks_are_zero
  iotests: add tests for blockdev-amend
  block/qcow2: implement blockdev-amend
  block/crypto: implement blockdev-amend
  block/core: add generic infrastructure for x-blockdev-amend qmp command
  iotests: qemu-img tests for luks key management
  block/qcow2: extend qemu-img amend interface with crypto options
  block/crypto: implement the encryption key management
  block/crypto: rename two functions
  block/amend: refactor qcow2 amend options
  block/amend: separate amend and create options for qemu-img
  ...

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

3 files changed, 53 insertions, 12 deletions

diff --git a/include/block/block.h b/include/block/block.h
index e8fc814..bca3bb8 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -22,11 +22,6 @@ typedef struct BlockDriverInfo {
     int64_t vm_state_offset;
     bool is_dirty;
     /*
-     * True if unallocated blocks read back as zeroes. This is equivalent
-     * to the LBPRZ flag in the SCSI logical block provisioning page.
-     */
-    bool unallocated_blocks_are_zero;
-    /*
      * True if this block driver only supports compressed writes
      */
     bool needs_compressed_writes;
@@ -450,6 +445,7 @@ typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
                                       int64_t total_work_size, void *opaque);
 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
+                       bool force,
                        Error **errp);
 
 /* check if a named node can be replaced when doing drive-mirror */
@@ -488,7 +484,6 @@ int bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 int bdrv_has_zero_init_1(BlockDriverState *bs);
 int bdrv_has_zero_init(BlockDriverState *bs);
-bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
                       int64_t bytes, int64_t *pnum, int64_t *map,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 791de6a..3d6cf885 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -123,7 +123,17 @@ struct BlockDriver {
      */
     bool bdrv_needs_filename;
 
-    /* Set if a driver can support backing files */
+    /*
+     * Set if a driver can support backing files. This also implies the
+     * following semantics:
+     *
+     *  - Return status 0 of .bdrv_co_block_status means that corresponding
+     *    blocks are not allocated in this layer of backing-chain
+     *  - For such (unallocated) blocks, read will:
+     *    - fill buffer with zeros if there is no backing file
+     *    - read from the backing file otherwise, where the block layer
+     *      takes care of reading zeros beyond EOF if backing file is short
+     */
     bool supports_backing;
 
     /* For handling image reopen for split or non-split files */
@@ -141,12 +151,27 @@ struct BlockDriver {
     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
                           Error **errp);
     void (*bdrv_close)(BlockDriverState *bs);
+
+
     int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
                                        Error **errp);
     int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv,
                                             const char *filename,
                                             QemuOpts *opts,
                                             Error **errp);
+
+    int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
+                                      BlockdevAmendOptions *opts,
+                                      bool force,
+                                      Error **errp);
+
+    int (*bdrv_amend_options)(BlockDriverState *bs,
+                              QemuOpts *opts,
+                              BlockDriverAmendStatusCB *status_cb,
+                              void *cb_opaque,
+                              bool force,
+                              Error **errp);
+
     int (*bdrv_make_empty)(BlockDriverState *bs);
 
     /*
@@ -420,6 +445,10 @@ struct BlockDriver {
 
     /* List of options for creating images, terminated by name == NULL */
     QemuOptsList *create_opts;
+
+    /* List of options for image amend */
+    QemuOptsList *amend_opts;
+
     /*
      * If this driver supports reopening images this contains a
      * NULL-terminated list of the runtime options that can be
@@ -437,11 +466,6 @@ struct BlockDriver {
                                       BdrvCheckResult *result,
                                       BdrvCheckMode fix);
 
-    int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
-                              BlockDriverAmendStatusCB *status_cb,
-                              void *cb_opaque,
-                              Error **errp);
-
     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 
     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
diff --git a/include/crypto/block.h b/include/crypto/block.h
index c77ccaf..d274819 100644
--- a/include/crypto/block.h
+++ b/include/crypto/block.h
@@ -144,6 +144,28 @@ QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
                                    void *opaque,
                                    Error **errp);
 
+/**
+ * qcrypto_block_amend_options:
+ * @block: the block encryption object
+ *
+ * @readfunc: callback for reading data from the volume header
+ * @writefunc: callback for writing data to the volume header
+ * @opaque: data to pass to @readfunc and @writefunc
+ * @options: the new/amended encryption options
+ * @force: hint for the driver to allow unsafe operation
+ * @errp: error pointer
+ *
+ * Changes the crypto options of the encryption format
+ *
+ */
+int qcrypto_block_amend_options(QCryptoBlock *block,
+                                QCryptoBlockReadFunc readfunc,
+                                QCryptoBlockWriteFunc writefunc,
+                                void *opaque,
+                                QCryptoBlockAmendOptions *options,
+                                bool force,
+                                Error **errp);
+
 
 /**
  * qcrypto_block_calculate_payload_offset: