[Qemu-devel] [PATCH 0.14/master v2 0/4] Error messages for unsupoorted image format features

[Qemu-devel] [PATCH 0.14/master v2 0/4] Error messages for unsupoorted image format features

[Kevin Wolf]

With 0.15 we'll most likely get some incompatible image format extensions. This
series prepares 0.14 to output more helpful messages if it stumbles over a too
new image file.

Kevin Wolf (4):
  qerror: Add QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
  qcow2: Report error for version > 2
  qed: Report error for unsupported features
  qemu-img: Improve error messages for failed bdrv_open

 block/qcow2.c |   13 +++++++++++--
 block/qed.c   |    9 ++++++++-
 qemu-img.c    |   10 +++++++---
 qerror.c      |    5 +++++
 qerror.h      |    3 +++
 5 files changed, 34 insertions(+), 6 deletions(-)

-- 
1.7.2.3

[Qemu-devel] [PATCH v2 1/4] qerror: Add QERR_UNKNOWN_BLOCK_FORMAT_FEATURE

[Kevin Wolf]

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qerror.c |    5 +++++
 qerror.h |    3 +++
 2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/qerror.c b/qerror.c
index 9d0cdeb..4855604 100644
--- a/qerror.c
+++ b/qerror.c
@@ -201,6 +201,11 @@ static const QErrorStringTable qerror_table[] = {
         .desc      = "An undefined error has ocurred",
     },
     {
+        .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+        .desc      = "'%(device)' uses a %(format) feature which is not "
+                     "supported by this qemu version: %(feature)",
+    },
+    {
         .error_fmt = QERR_VNC_SERVER_FAILED,
         .desc      = "Could not start VNC server on %(target)",
     },
diff --git a/qerror.h b/qerror.h
index b0f69da..f732d45 100644
--- a/qerror.h
+++ b/qerror.h
@@ -165,6 +165,9 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_UNDEFINED_ERROR \
     "{ 'class': 'UndefinedError', 'data': {} }"
 
+#define QERR_UNKNOWN_BLOCK_FORMAT_FEATURE \
+    "{ 'class': 'UnknownBlockFormatFeature', 'data': { 'device': %s, 'format': %s, 'feature': %s } }"
+
 #define QERR_VNC_SERVER_FAILED \
     "{ 'class': 'VNCServerFailed', 'data': { 'target': %s } }"
 
-- 
1.7.2.3

[Qemu-devel] [PATCH v2 2/4] qcow2: Report error for version > 2

[Kevin Wolf]

The qcow2 driver is now declared responsible for any QCOW image that has
version 2 or greater (before this, version 3 would be detected as raw).

For everything newer than version 2, an error is reported.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 551b3c2..75b8bec 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -28,6 +28,7 @@
 #include "aes.h"
 #include "block/qcow2.h"
 #include "qemu-error.h"
+#include "qerror.h"
 
 /*
   Differences with QCOW:
@@ -59,7 +60,7 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
 
     if (buf_size >= sizeof(QCowHeader) &&
         be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
-        be32_to_cpu(cow_header->version) == QCOW_VERSION)
+        be32_to_cpu(cow_header->version) >= QCOW_VERSION)
         return 100;
     else
         return 0;
@@ -163,10 +164,18 @@ static int qcow2_open(BlockDriverState *bs, int flags)
     be64_to_cpus(&header.snapshots_offset);
     be32_to_cpus(&header.nb_snapshots);
 
-    if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) {
+    if (header.magic != QCOW_MAGIC) {
         ret = -EINVAL;
         goto fail;
     }
+    if (header.version != QCOW_VERSION) {
+        char version[64];
+        snprintf(version, sizeof(version), "QCOW version %d", header.version);
+        qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+            bs->device_name, "qcow2", version);
+        ret = -ENOTSUP;
+        goto fail;
+    }
     if (header.cluster_bits < MIN_CLUSTER_BITS ||
         header.cluster_bits > MAX_CLUSTER_BITS) {
         ret = -EINVAL;
-- 
1.7.2.3

[Qemu-devel] [PATCH v2 3/4] qed: Report error for unsupported features

[Kevin Wolf]

Instead of just returning -ENOTSUP, generate a more detailed error.

Unfortunately we don't have a helpful text for features that we don't know yet,
so just print the feature mask. It might be useful at least if someone asks for
help.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qed.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/block/qed.c b/block/qed.c
index 3273448..75ae244 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -14,6 +14,7 @@
 
 #include "trace.h"
 #include "qed.h"
+#include "qerror.h"
 
 static void qed_aio_cancel(BlockDriverAIOCB *blockacb)
 {
@@ -311,7 +312,13 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
         return -EINVAL;
     }
     if (s->header.features & ~QED_FEATURE_MASK) {
-        return -ENOTSUP; /* image uses unsupported feature bits */
+        /* image uses unsupported feature bits */
+        char buf[64];
+        snprintf(buf, sizeof(buf), "%" PRIx64,
+            s->header.features & ~QED_FEATURE_MASK);
+        qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+            bs->device_name, "QED", buf);
+        return -ENOTSUP;
     }
     if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
         return -EINVAL;
-- 
1.7.2.3

[Qemu-devel] Re: [PATCH v2 3/4] qed: Report error for unsupported features

[Stefan Hajnoczi]

On Thu, Feb 10, 2011 at 11:18 AM, Kevin Wolf <kwolf@redhat.com> wrote:
> Instead of just returning -ENOTSUP, generate a more detailed error.
>
> Unfortunately we don't have a helpful text for features that we don't know yet,
> so just print the feature mask. It might be useful at least if someone asks for
> help.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/qed.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)

Thanks!

Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

[Qemu-devel] [PATCH v2 4/4] qemu-img: Improve error messages for failed bdrv_open

[Kevin Wolf]

Output the error message string of the bdrv_open return code. Also set a
non-empty device name for the images because the unknown feature error message
includes it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 4a37358..7e3cc4c 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -213,8 +213,9 @@ static BlockDriverState *bdrv_new_open(const char *filename,
     BlockDriverState *bs;
     BlockDriver *drv;
     char password[256];
+    int ret;
 
-    bs = bdrv_new("");
+    bs = bdrv_new("image");
 
     if (fmt) {
         drv = bdrv_find_format(fmt);
@@ -225,10 +226,13 @@ static BlockDriverState *bdrv_new_open(const char *filename,
     } else {
         drv = NULL;
     }
-    if (bdrv_open(bs, filename, flags, drv) < 0) {
-        error_report("Could not open '%s'", filename);
+
+    ret = bdrv_open(bs, filename, flags, drv);
+    if (ret < 0) {
+        error_report("Could not open '%s': %s", filename, strerror(-ret));
         goto fail;
     }
+
     if (bdrv_is_encrypted(bs)) {
         printf("Disk image '%s' is encrypted.\n", filename);
         if (read_password(password, sizeof(password)) < 0) {
-- 
1.7.2.3

[Qemu-devel] Re: [PATCH 0.14/master v2 0/4] Error messages for unsupoorted image format features

[Anthony Liguori]

On 02/10/2011 12:18 PM, Kevin Wolf wrote:
> With 0.15 we'll most likely get some incompatible image format extensions. This
> series prepares 0.14 to output more helpful messages if it stumbles over a too
> new image file.
>
> Kevin Wolf (4):
>    qerror: Add QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
>    qcow2: Report error for version>  2
>    qed: Report error for unsupported features
>    qemu-img: Improve error messages for failed bdrv_open
>    

Whole series:

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>

>   block/qcow2.c |   13 +++++++++++--
>   block/qed.c   |    9 ++++++++-
>   qemu-img.c    |   10 +++++++---
>   qerror.c      |    5 +++++
>   qerror.h      |    3 +++
>   5 files changed, 34 insertions(+), 6 deletions(-)
>
>