diff mbox

[4/7] block: Parse 'detect-zeroes' in bdrv_open_common()

Message ID 1474405737-2092-5-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf Sept. 20, 2016, 9:08 p.m. UTC 
Amonst others, this means that you can now use the 'detect-zeroes'
option for non-top-level nodes in blockdev-add, like the QAPI schema
promises.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c    | 33 +++++++++++++++++++++++++++++++++
 blockdev.c |  9 +--------
 2 files changed, 34 insertions(+), 8 deletions(-)

Comments

Eric Blake Sept. 21, 2016, 7:16 p.m. UTC | #1 
On 09/20/2016 04:08 PM, Kevin Wolf wrote:
> Amonst others, this means that you can now use the 'detect-zeroes'

s/Amonst/Amongst/ (that's UK spelling; US shortens it to Among)

> option for non-top-level nodes in blockdev-add, like the QAPI schema
> promises.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c    | 33 +++++++++++++++++++++++++++++++++
>  blockdev.c |  9 +--------
>  2 files changed, 34 insertions(+), 8 deletions(-)
> 

> @@ -990,6 +997,32 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
>          }
>      }
>  
> +    detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
> +    if (detect_zeroes) {
> +        BlockdevDetectZeroesOptions value =
> +            qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
> +                            qemu_opt_get(opts, "detect-zeroes"),

Why do we have to repeat the qemu_opt_get() here, instead of just
passing in the just-collected detect_zeroes local variable?

Otherwise looks fine.
diff mbox

Patch

diff --git a/block.c b/block.c
index 1e9d66b..b9c780e 100644
--- a/block.c
+++ b/block.c
@@ -41,6 +41,7 @@ 
 #include "qapi-event.h"
 #include "qemu/cutils.h"
 #include "qemu/id.h"
+#include "qapi/util.h"
 
 #ifdef CONFIG_BSD
 #include <sys/ioctl.h>
@@ -906,6 +907,11 @@  static QemuOptsList bdrv_runtime_opts = {
             .type = QEMU_OPT_BOOL,
             .help = "Node is opened in read-only mode",
         },
+        {
+            .name = "detect-zeroes",
+            .type = QEMU_OPT_STRING,
+            .help = "try to optimize zero writes (off, on, unmap)",
+        },
         { /* end of list */ }
     },
 };
@@ -922,6 +928,7 @@  static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
     const char *filename;
     const char *driver_name = NULL;
     const char *node_name = NULL;
+    const char *detect_zeroes;
     QemuOpts *opts;
     BlockDriver *drv;
     Error *local_err = NULL;
@@ -990,6 +997,32 @@  static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
         }
     }
 
+    detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
+    if (detect_zeroes) {
+        BlockdevDetectZeroesOptions value =
+            qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
+                            qemu_opt_get(opts, "detect-zeroes"),
+                            BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
+                            BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
+                            &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            ret = -EINVAL;
+            goto fail_opts;
+        }
+
+        if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
+            !(bs->open_flags & BDRV_O_UNMAP))
+        {
+            error_setg(errp, "setting detect-zeroes to unmap is not allowed "
+                             "without setting discard operation to unmap");
+            ret = -EINVAL;
+            goto fail_opts;
+        }
+
+        bs->detect_zeroes = value;
+    }
+
     if (filename != NULL) {
         pstrcpy(bs->filename, sizeof(bs->filename), filename);
     } else {
diff --git a/blockdev.c b/blockdev.c
index a611cc8..b847ee9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -658,7 +658,6 @@  static BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
     BlockDriverState *bs;
     QemuOpts *opts;
     Error *local_error = NULL;
-    BlockdevDetectZeroesOptions detect_zeroes;
     int bdrv_flags = 0;
 
     opts = qemu_opts_create(&qemu_root_bds_opts, NULL, 1, errp);
@@ -673,7 +672,7 @@  static BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
     }
 
     extract_common_blockdev_options(opts, &bdrv_flags, NULL, NULL,
-                                    &detect_zeroes, &local_error);
+                                    NULL, &local_error);
     if (local_error) {
         error_propagate(errp, local_error);
         goto fail;
@@ -695,8 +694,6 @@  static BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
         goto fail_no_bs_opts;
     }
 
-    bs->detect_zeroes = detect_zeroes;
-
 fail_no_bs_opts:
     qemu_opts_del(opts);
     return bs;
@@ -4140,10 +4137,6 @@  static QemuOptsList qemu_root_bds_opts = {
             .name = "copy-on-read",
             .type = QEMU_OPT_BOOL,
             .help = "copy read data from backing file into image file",
-        },{
-            .name = "detect-zeroes",
-            .type = QEMU_OPT_STRING,
-            .help = "try to optimize zero writes (off, on, unmap)",
         },
         { /* end of list */ }
     },