Re: [Qemu-devel] [PATCH v13 4/6] qapi: introduce PreallocMode and a new PreallocMode full.

[Hu Tao]

On Tue, Sep 02, 2014 at 11:32:50PM +0200, Max Reitz wrote:
> On 29.08.2014 10:33, Hu Tao wrote:
> >This patch prepares for the subsequent patches.
> >
> >Signed-off-by: Hu Tao <address@hidden>
> >---
> >  block/qcow2.c              | 23 +++++++++++++++--------
> >  qapi/block-core.json       | 16 ++++++++++++++++
> >  tests/qemu-iotests/049.out |  2 +-
> >  3 files changed, 32 insertions(+), 9 deletions(-)
> >
> >diff --git a/block/qcow2.c b/block/qcow2.c
> >index cf27c3f..95fb240 100644
> >--- a/block/qcow2.c
> >+++ b/block/qcow2.c
> >@@ -30,6 +30,7 @@
> >  #include "qemu/error-report.h"
> >  #include "qapi/qmp/qerror.h"
> >  #include "qapi/qmp/qbool.h"
> >+#include "qapi/util.h"
> >  #include "trace.h"
> >  #include "qemu/option_int.h"
> >@@ -1738,7 +1739,7 @@ static int preallocate(BlockDriverState *bs)
> >  static int qcow2_create2(const char *filename, int64_t total_size,
> >                           const char *backing_file, const char 
> > *backing_format,
> >-                         int flags, size_t cluster_size, int prealloc,
> >+                         int flags, size_t cluster_size, PreallocMode 
> >prealloc,
> >                           QemuOpts *opts, int version,
> >                           Error **errp)
> >  {
> >@@ -1915,7 +1916,7 @@ static int qcow2_create(const char *filename, QemuOpts 
> >*opts, Error **errp)
> >      uint64_t size = 0;
> >      int flags = 0;
> >      size_t cluster_size = DEFAULT_CLUSTER_SIZE;
> >-    int prealloc = 0;
> >+    PreallocMode prealloc = PREALLOC_MODE_OFF;
> >      int version = 3;
> >      Error *local_err = NULL;
> >      int ret;
> >@@ -1931,12 +1932,11 @@ static int qcow2_create(const char *filename, 
> >QemuOpts *opts, Error **errp)
> >      cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
> >                                           DEFAULT_CLUSTER_SIZE);
> >      buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
> >-    if (!buf || !strcmp(buf, "off")) {
> >-        prealloc = 0;
> >-    } else if (!strcmp(buf, "metadata")) {
> >-        prealloc = 1;
> >-    } else {
> >-        error_setg(errp, "Invalid preallocation mode: '%s'", buf);
> >+    prealloc = qapi_enum_parse(PreallocMode_lookup, buf,
> >+                               PREALLOC_MODE_MAX, PREALLOC_MODE_OFF,
> >+                               &local_err);
> >+    if (local_err) {
> >+        error_propagate(errp, local_err);
> >          ret = -EINVAL;
> >          goto finish;
> >      }
> >@@ -1958,6 +1958,13 @@ static int qcow2_create(const char *filename, 
> >QemuOpts *opts, Error **errp)
> >          flags |= BLOCK_FLAG_LAZY_REFCOUNTS;
> >      }
> >+    if (prealloc && prealloc != PREALLOC_MODE_METADATA) {
> >+        ret = -1;
> 
> Since the return value is expected to be -errno, I'd propose "ret =
> -EINVAL;" here. With that fixed (or a good explanation why we want
> -1 here):

Good.

> 
> Reviewed-by: Max Reitz <address@hidden>
> 
> >+        error_setg(errp, "Unsupported preallocate mode: %s",
> >+                   PreallocMode_lookup[prealloc]);
> >+        goto finish;
> >+    }
> >+
> >      if (backing_file && prealloc) {
> >          error_setg(errp, "Backing file and preallocation cannot be used at 
> > "
> >                     "the same time");
> >diff --git a/qapi/block-core.json b/qapi/block-core.json
> >index fb74c56..543b00b 100644
> >--- a/qapi/block-core.json
> >+++ b/qapi/block-core.json
> >@@ -1679,3 +1679,19 @@
> >              'len'   : 'int',
> >              'offset': 'int',
> >              'speed' : 'int' } }
> >+
> >+# @PreallocMode
> >+#
> >+# Preallocation mode of QEMU image file
> >+#
> >+# @off: no preallocation
> >+# @metadata: preallocate only for metadata
> >+# @full: preallocate all data by calling posix_fallocate() if it is
> >+#        available, otherwise by writing zeros to device to ensure disk
> >+#        space is really available. @full preallocation also sets up
> >+#        metadata correctly.
> >+#
> >+# Since 2.2
> >+##
> >+{ 'enum': 'PreallocMode',
> >+  'data': [ 'off', 'metadata', 'full' ] }
> >diff --git a/tests/qemu-iotests/049.out b/tests/qemu-iotests/049.out
> >index 71ca44d..09ca0ae 100644
> >--- a/tests/qemu-iotests/049.out
> >+++ b/tests/qemu-iotests/049.out
> >@@ -179,7 +179,7 @@ qemu-img create -f qcow2 -o preallocation=metadata 
> >TEST_DIR/t.qcow2 64M
> >  Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off 
> > cluster_size=65536 preallocation='metadata' lazy_refcounts=off
> >  qemu-img create -f qcow2 -o preallocation=1234 TEST_DIR/t.qcow2 64M
> >-qemu-img: TEST_DIR/t.qcow2: Invalid preallocation mode: '1234'
> >+qemu-img: TEST_DIR/t.qcow2: invalid parameter value: 1234
> >  Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off 
> > cluster_size=65536 preallocation='1234' lazy_refcounts=off
> >  == Check encryption option ==