[Qemu-block] [RFC PATCH 53/56] block: Make blockdev-add byte counts unsigned in QAPI/QMP

[Markus Armbruster]

File offsets, sizes and alignments should use QAPI type 'size'
(uint64_t).  blockdev-add parameters are 'int' (int64_t):
BlockdevOptionsNull member @size; BlockdevOptionsQcow2 members
@cache-size, @l2-cache-size, @refcount-cache-size; BlockdevOptionsNfs
members @readahead-size, @page-cache-size; BlockdevOptionsCurlBase
member @readahead; BlockdevOptionsRaw members @offset, @size.

The block drivers get their values with qemu_opt_get_size(), which
returns uint64_t.  They store them in uint64_t variables, except for
the null driver, which stores in BDRVNullState member int64_t length.

Change these BlockdevOptionsFOO members to 'size'.

Change BDRVNullState member length to uint64_t.  This moves the
implicit conversion to int64_t from null_file_open() to
null_getlength().  No worse than before.

blockdev-add and -blockdev now accept values between 2^63 and 2^64-1.
They accept negative values as before, because that's how the QObject
input visitor works for backward compatibility.

Values above 2^63 are unlikely to actually work; the block subsystem
isn't prepared for them.  Again, no worse than before.

Aside: we call the same thing @readahead-size in one place, and
@readahead in another place.  Sad.

Signed-off-by: Markus Armbruster <address@hidden>
---
 block/null.c         |  2 +-
 qapi/block-core.json | 22 +++++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/block/null.c b/block/null.c
index 876f909..2ab0e70 100644
--- a/block/null.c
+++ b/block/null.c
@@ -20,7 +20,7 @@
 #define NULL_OPT_ZEROES  "read-zeroes"
 
 typedef struct {
-    int64_t length;
+    uint64_t length;
     int64_t latency_ns;
     bool read_zeroes;
 } BDRVNullState;
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 64b84a5..3482f8c 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2189,7 +2189,7 @@
 # Since: 2.9
 ##
 { 'struct': 'BlockdevOptionsNull',
-  'data': { '*size': 'int', '*latency-ns': 'uint64' } }
+  'data': { '*size': 'size', '*latency-ns': 'uint64' } }
 
 ##
 # @BlockdevOptionsVVFAT:
@@ -2421,9 +2421,9 @@
             '*pass-discard-snapshot': 'bool',
             '*pass-discard-other': 'bool',
             '*overlap-check': 'Qcow2OverlapChecks',
-            '*cache-size': 'int',
-            '*l2-cache-size': 'int',
-            '*refcount-cache-size': 'int',
+            '*cache-size': 'size',
+            '*l2-cache-size': 'size',
+            '*refcount-cache-size': 'size',
             '*cache-clean-interval': 'int',
             '*encrypt': 'BlockdevQcow2Encryption' } }
 
@@ -2568,9 +2568,9 @@
 { 'struct': 'BlockdevOptionsBlkdebug',
   'data': { 'image': 'BlockdevRef',
             '*config': 'str',
-            '*align': 'int', '*max-transfer': 'int32',
-            '*opt-write-zero': 'int32', '*max-write-zero': 'int32',
-            '*opt-discard': 'int32', '*max-discard': 'int32',
+            '*align': 'size', '*max-transfer': 'size',
+            '*opt-write-zero': 'size', '*max-write-zero': 'size',
+            '*opt-discard': 'size', '*max-discard': 'size',
             '*inject-error': ['BlkdebugInjectErrorOptions'],
             '*set-state': ['BlkdebugSetStateOptions'] } }
 
@@ -2862,8 +2862,8 @@
             '*user': 'int',
             '*group': 'int',
             '*tcp-syn-count': 'int',
-            '*readahead-size': 'int',
-            '*page-cache-size': 'int',
+            '*readahead-size': 'size',
+            '*page-cache-size': 'size',
             '*debug': 'int' } }
 
 ##
@@ -2893,7 +2893,7 @@
 ##
 { 'struct': 'BlockdevOptionsCurlBase',
   'data': { 'url': 'str',
-            '*readahead': 'int',
+            '*readahead': 'size',
             '*timeout': 'int',
             '*username': 'str',
             '*password-secret': 'str',
@@ -3001,7 +3001,7 @@
 ##
 { 'struct': 'BlockdevOptionsRaw',
   'base': 'BlockdevOptionsGenericFormat',
-  'data': { '*offset': 'int', '*size': 'int' } }
+  'data': { '*offset': 'size', '*size': 'size' } }
 
 ##
 # @BlockdevOptionsVxHS:
-- 
2.7.5