[Qemu-devel] [PULL 0/8] Block patches for 2.0.0-rc1

[Qemu-devel] [PULL 0/8] Block patches for 2.0.0-rc1

[Kevin Wolf]

The following changes since commit 059b3527f0229f4d60fd77a317503d42abd5e50f:

  Merge remote-tracking branch 'remotes/kraxel/tags/pull-vnc-2' into staging (2014-03-18 16:39:29 +0000)

are available in the git repository at:


  git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to 198fd05c357afff22f0b0e02639937519ed49b1f:

  dataplane: fix implicit IOThread refcount (2014-03-19 09:45:25 +0100)

----------------------------------------------------------------
Block patches for 2.0.0-rc1

----------------------------------------------------------------
Kevin Wolf (1):
      block: Add error handling to bdrv_invalidate_cache()

Maria Kustova (2):
      qemu-io-cmds: Fixed typo in example for writev.
      qemu-io: Extended "--cmd" description in usage text

Max Reitz (2):
      qcow2: Correct comment for realloc_refcount_block()
      qcow2: Fix fail path in realloc_refcount_block()

Peter Lieven (2):
      block/nfs: bump libnfs requirement to 1.9.3
      block/nfs: report errors from libnfs

Stefan Hajnoczi (1):
      dataplane: fix implicit IOThread refcount

 block.c                         | 28 ++++++++++++++++++++++------
 block/nfs.c                     |  3 +++
 block/qcow2-refcount.c          | 36 +++++++++++++++++++-----------------
 block/qcow2.c                   | 22 +++++++++++++++++++---
 block/qed.c                     | 21 ++++++++++++++++++---
 block/quorum.c                  |  9 +++++++--
 configure                       |  2 +-
 hw/block/dataplane/virtio-blk.c |  2 +-
 include/block/block.h           |  4 ++--
 include/block/block_int.h       |  2 +-
 migration.c                     |  8 +++++++-
 qemu-io-cmds.c                  |  2 +-
 qemu-io.c                       |  9 ++++++---
 13 files changed, 107 insertions(+), 41 deletions(-)

[Qemu-devel] [PULL 1/8] block: Add error handling to bdrv_invalidate_cache()

[Kevin Wolf]

If it returns an error, the migrated VM will not be started, but qemu
exits with an error message.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
---
 block.c                   | 28 ++++++++++++++++++++++------
 block/qcow2.c             | 22 +++++++++++++++++++---
 block/qed.c               | 21 ++++++++++++++++++---
 block/quorum.c            |  9 +++++++--
 include/block/block.h     |  4 ++--
 include/block/block_int.h |  2 +-
 migration.c               |  8 +++++++-
 7 files changed, 76 insertions(+), 18 deletions(-)

diff --git a/block.c b/block.c
index 53f5b44..acb70fd 100644
--- a/block.c
+++ b/block.c
@@ -4781,27 +4781,43 @@ flush_parent:
     return bdrv_co_flush(bs->file);
 }
 
-void bdrv_invalidate_cache(BlockDriverState *bs)
+void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
 {
+    Error *local_err = NULL;
+    int ret;
+
     if (!bs->drv)  {
         return;
     }
 
     if (bs->drv->bdrv_invalidate_cache) {
-        bs->drv->bdrv_invalidate_cache(bs);
+        bs->drv->bdrv_invalidate_cache(bs, &local_err);
     } else if (bs->file) {
-        bdrv_invalidate_cache(bs->file);
+        bdrv_invalidate_cache(bs->file, &local_err);
+    }
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
     }
 
-    refresh_total_sectors(bs, bs->total_sectors);
+    ret = refresh_total_sectors(bs, bs->total_sectors);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not refresh total sector count");
+        return;
+    }
 }
 
-void bdrv_invalidate_cache_all(void)
+void bdrv_invalidate_cache_all(Error **errp)
 {
     BlockDriverState *bs;
+    Error *local_err = NULL;
 
     QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-        bdrv_invalidate_cache(bs);
+        bdrv_invalidate_cache(bs, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
     }
 }
 
diff --git a/block/qcow2.c b/block/qcow2.c
index 945c9d6..b9dc960 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1156,7 +1156,7 @@ static void qcow2_close(BlockDriverState *bs)
     qcow2_free_snapshots(bs);
 }
 
-static void qcow2_invalidate_cache(BlockDriverState *bs)
+static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp)
 {
     BDRVQcowState *s = bs->opaque;
     int flags = s->flags;
@@ -1164,6 +1164,8 @@ static void qcow2_invalidate_cache(BlockDriverState *bs)
     AES_KEY aes_decrypt_key;
     uint32_t crypt_method = 0;
     QDict *options;
+    Error *local_err = NULL;
+    int ret;
 
     /*
      * Backing files are read-only which makes all of their metadata immutable,
@@ -1178,11 +1180,25 @@ static void qcow2_invalidate_cache(BlockDriverState *bs)
 
     qcow2_close(bs);
 
-    bdrv_invalidate_cache(bs->file);
+    bdrv_invalidate_cache(bs->file, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
 
     memset(s, 0, sizeof(BDRVQcowState));
     options = qdict_clone_shallow(bs->options);
-    qcow2_open(bs, options, flags, NULL);
+
+    ret = qcow2_open(bs, options, flags, &local_err);
+    if (local_err) {
+        error_setg(errp, "Could not reopen qcow2 layer: %s",
+                   error_get_pretty(local_err));
+        error_free(local_err);
+        return;
+    } else if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not reopen qcow2 layer");
+        return;
+    }
 
     QDECREF(options);
 
diff --git a/block/qed.c b/block/qed.c
index 837accd..3bd9db9 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1558,16 +1558,31 @@ static int bdrv_qed_change_backing_file(BlockDriverState *bs,
     return ret;
 }
 
-static void bdrv_qed_invalidate_cache(BlockDriverState *bs)
+static void bdrv_qed_invalidate_cache(BlockDriverState *bs, Error **errp)
 {
     BDRVQEDState *s = bs->opaque;
+    Error *local_err = NULL;
+    int ret;
 
     bdrv_qed_close(bs);
 
-    bdrv_invalidate_cache(bs->file);
+    bdrv_invalidate_cache(bs->file, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
 
     memset(s, 0, sizeof(BDRVQEDState));
-    bdrv_qed_open(bs, NULL, bs->open_flags, NULL);
+    ret = bdrv_qed_open(bs, NULL, bs->open_flags, &local_err);
+    if (local_err) {
+        error_setg(errp, "Could not reopen qed layer: %s",
+                   error_get_pretty(local_err));
+        error_free(local_err);
+        return;
+    } else if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not reopen qed layer");
+        return;
+    }
 }
 
 static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result,
diff --git a/block/quorum.c b/block/quorum.c
index 33bf2ae..7f580a8 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -625,13 +625,18 @@ static int64_t quorum_getlength(BlockDriverState *bs)
     return result;
 }
 
-static void quorum_invalidate_cache(BlockDriverState *bs)
+static void quorum_invalidate_cache(BlockDriverState *bs, Error **errp)
 {
     BDRVQuorumState *s = bs->opaque;
+    Error *local_err = NULL;
     int i;
 
     for (i = 0; i < s->num_children; i++) {
-        bdrv_invalidate_cache(s->bs[i]);
+        bdrv_invalidate_cache(s->bs[i], &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
     }
 }
 
diff --git a/include/block/block.h b/include/block/block.h
index bd34d14..1ed55d8 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -329,8 +329,8 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
         BlockDriverCompletionFunc *cb, void *opaque);
 
 /* Invalidate any cached metadata used by image formats */
-void bdrv_invalidate_cache(BlockDriverState *bs);
-void bdrv_invalidate_cache_all(void);
+void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
+void bdrv_invalidate_cache_all(Error **errp);
 
 void bdrv_clear_incoming_migration_all(void);
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 4fc5ea8..cd5bc73 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -153,7 +153,7 @@ struct BlockDriver {
     /*
      * Invalidate any cached meta-data.
      */
-    void (*bdrv_invalidate_cache)(BlockDriverState *bs);
+    void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
 
     /*
      * Flushes all data that was already written to the OS all the way down to
diff --git a/migration.c b/migration.c
index 00f465e..e0e24d4 100644
--- a/migration.c
+++ b/migration.c
@@ -101,6 +101,7 @@ void qemu_start_incoming_migration(const char *uri, Error **errp)
 static void process_incoming_migration_co(void *opaque)
 {
     QEMUFile *f = opaque;
+    Error *local_err = NULL;
     int ret;
 
     ret = qemu_loadvm_state(f);
@@ -115,7 +116,12 @@ static void process_incoming_migration_co(void *opaque)
 
     bdrv_clear_incoming_migration_all();
     /* Make sure all file formats flush their mutable metadata */
-    bdrv_invalidate_cache_all();
+    bdrv_invalidate_cache_all(&local_err);
+    if (local_err) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        exit(EXIT_FAILURE);
+    }
 
     if (autostart) {
         vm_start();
-- 
1.8.3.1

[Qemu-devel] [PULL 2/8] qemu-io-cmds: Fixed typo in example for writev.

[Kevin Wolf]

From: Maria Kustova <maxa@catit.be>

Signed-off-by: Maria Kustova <maria.k@catit.be>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io-cmds.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index fb1db53..60c1ceb 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -1087,7 +1087,7 @@ writev_help(void)
 " writes a range of bytes from the given offset source from multiple buffers\n"
 "\n"
 " Example:\n"
-" 'write 512 1k 1k' - writes 2 kilobytes at 512 bytes into the open file\n"
+" 'writev 512 1k 1k' - writes 2 kilobytes at 512 bytes into the open file\n"
 "\n"
 " Writes into a segment of the currently open file, using a buffer\n"
 " filled with a set pattern (0xcdcdcdcd).\n"
-- 
1.8.3.1

[Qemu-devel] [PULL 3/8] qemu-io: Extended "--cmd" description in usage text

[Kevin Wolf]

From: Maria Kustova <maxa@catit.be>

It's not clear from the usage description that "--cmd" option accepts
its argument as a string, so any special symbols have to be quoted from
the shell.

Updates in usage text:
 - Specified parameter format for "--cmd" option.
 - Added an instruction how to get help for "--cmd" option.

Signed-off-by: Maria Kustova <maria.k@catit.be>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index 2d119c2..5d7b53f 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -193,10 +193,11 @@ static const cmdinfo_t quit_cmd = {
 static void usage(const char *name)
 {
     printf(
-"Usage: %s [-h] [-V] [-rsnm] [-c cmd] ... [file]\n"
+"Usage: %s [-h] [-V] [-rsnm] [-c STRING] ... [file]\n"
 "QEMU Disk exerciser\n"
 "\n"
-"  -c, --cmd            command to execute\n"
+"  -c, --cmd STRING     execute command with its arguments\n"
+"                       from the given string\n"
 "  -r, --read-only      export read-only\n"
 "  -s, --snapshot       use snapshot file\n"
 "  -n, --nocache        disable host cache\n"
@@ -207,8 +208,10 @@ static void usage(const char *name)
 "  -T, --trace FILE     enable trace events listed in the given file\n"
 "  -h, --help           display this help and exit\n"
 "  -V, --version        output version information and exit\n"
+"\n"
+"See '%s -c help' for information on available commands."
 "\n",
-    name);
+    name, name);
 }
 
 static char *get_prompt(void)
-- 
1.8.3.1

[Qemu-devel] [PULL 4/8] qcow2: Correct comment for realloc_refcount_block()

[Kevin Wolf]

From: Max Reitz <mreitz@redhat.com>

Contrary to the comment describing this function's behavior, it does not
return 0 on success, but rather the offset of the newly allocated
cluster. This patch adjusts the comment accordingly to reflect the
actual behavior.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-refcount.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 6151148..3f2ed08 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1383,7 +1383,7 @@ static int write_reftable_entry(BlockDriverState *bs, int rt_index)
  * does _not_ decrement the reference count for the currently occupied cluster.
  *
  * This function prints an informative message to stderr on error (and returns
- * -errno); on success, 0 is returned.
+ * -errno); on success, the offset of the newly allocated cluster is returned.
  */
 static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
                                       uint64_t offset)
-- 
1.8.3.1

[Qemu-devel] [PULL 5/8] qcow2: Fix fail path in realloc_refcount_block()

[Kevin Wolf]

From: Max Reitz <mreitz@redhat.com>

If qcow2_alloc_clusters() fails, new_offset and ret will both be
negative after the fail label, thus passing the first if condition and
subsequently resulting in a call of qcow2_free_clusters() with an
invalid (negative) offset parameter. Fix this by introducing a new label
"fail_free_cluster" which is only invoked if new_offset is indeed
pointing to a newly allocated cluster that should be cleaned up by
freeing it.

While we're at it, clean up the whole fail path. qcow2_cache_put()
should (and actually can) never fail, hence the return value can safely
be ignored (aside from asserting that it indeed did not fail).

Furthermore, there is no reason to give QCOW2_DISCARD_ALWAYS to
qcow2_free_clusters(), a mere QCOW2_DISCARD_OTHER will suffice.

Ultimately, rename the "fail" label to "done", as it is invoked both on
failure and success.

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-refcount.c | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 3f2ed08..4a2df5f 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1399,14 +1399,14 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
         fprintf(stderr, "Could not allocate new cluster: %s\n",
                 strerror(-new_offset));
         ret = new_offset;
-        goto fail;
+        goto done;
     }
 
     /* fetch current refcount block content */
     ret = qcow2_cache_get(bs, s->refcount_block_cache, offset, &refcount_block);
     if (ret < 0) {
         fprintf(stderr, "Could not fetch refcount block: %s\n", strerror(-ret));
-        goto fail;
+        goto fail_free_cluster;
     }
 
     /* new block has not yet been entered into refcount table, therefore it is
@@ -1417,8 +1417,7 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
                 "check failed: %s\n", strerror(-ret));
         /* the image will be marked corrupt, so don't even attempt on freeing
          * the cluster */
-        new_offset = 0;
-        goto fail;
+        goto done;
     }
 
     /* write to new block */
@@ -1426,7 +1425,7 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
             s->cluster_sectors);
     if (ret < 0) {
         fprintf(stderr, "Could not write refcount block: %s\n", strerror(-ret));
-        goto fail;
+        goto fail_free_cluster;
     }
 
     /* update refcount table */
@@ -1436,24 +1435,27 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
     if (ret < 0) {
         fprintf(stderr, "Could not update refcount table: %s\n",
                 strerror(-ret));
-        goto fail;
+        goto fail_free_cluster;
     }
 
-fail:
-    if (new_offset && (ret < 0)) {
-        qcow2_free_clusters(bs, new_offset, s->cluster_size,
-                QCOW2_DISCARD_ALWAYS);
-    }
+    goto done;
+
+fail_free_cluster:
+    qcow2_free_clusters(bs, new_offset, s->cluster_size, QCOW2_DISCARD_OTHER);
+
+done:
     if (refcount_block) {
-        if (ret < 0) {
-            qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
-        } else {
-            ret = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
-        }
+        /* This should never fail, as it would only do so if the given refcount
+         * block cannot be found in the cache. As this is impossible as long as
+         * there are no bugs, assert the success. */
+        int tmp = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block);
+        assert(tmp == 0);
     }
+
     if (ret < 0) {
         return ret;
     }
+
     return new_offset;
 }
 
-- 
1.8.3.1

[Qemu-devel] [PULL 6/8] block/nfs: bump libnfs requirement to 1.9.3

[Kevin Wolf]

From: Peter Lieven <pl@kamp.de>

libnfs prior to 1.9.3 contains a bug that will report
wrong transfer sizes if the file offset grows beyond 4GB
and RPC responses are received out of order. this
error is not detectable and fixable in qemu.

additionally 1.9.3 introduces support for handling short
read/writes in general and takes care of the necessary
retransmissions internally.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index 2bc6b77..aae617e 100755
--- a/configure
+++ b/configure
@@ -3868,7 +3868,7 @@ fi
 ##########################################
 # Do we have libnfs
 if test "$libnfs" != "no" ; then
-  if $pkg_config --atleast-version=1.9.2 libnfs; then
+  if $pkg_config --atleast-version=1.9.3 libnfs; then
     libnfs="yes"
     libnfs_libs=$($pkg_config --libs libnfs)
     LIBS="$LIBS $libnfs_libs"
-- 
1.8.3.1

[Qemu-devel] [PULL 7/8] block/nfs: report errors from libnfs

[Kevin Wolf]

From: Peter Lieven <pl@kamp.de>

if an NFS operation fails we should report what libnfs knows
about the failure. It is likely more than just an error code.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/nfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block/nfs.c b/block/nfs.c
index ef731f0..98aa363 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -112,6 +112,9 @@ nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
     if (task->ret == 0 && task->st) {
         memcpy(task->st, data, sizeof(struct stat));
     }
+    if (task->ret < 0) {
+        error_report("NFS Error: %s", nfs_get_error(nfs));
+    }
     if (task->co) {
         task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task);
         qemu_bh_schedule(task->bh);
-- 
1.8.3.1

[Qemu-devel] [PULL 8/8] dataplane: fix implicit IOThread refcount

[Kevin Wolf]

From: Stefan Hajnoczi <stefanha@redhat.com>

When creating an IOThread implicitly (the user did not specify
x-iothread=<id>) remember that iothread_find() does not return the
object with an incremented refcount.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/block/dataplane/virtio-blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index a5afc21..f558b45 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -393,7 +393,6 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
     if (blk->iothread) {
         s->internal_iothread = false;
         s->iothread = blk->iothread;
-        object_ref(OBJECT(s->iothread));
     } else {
         /* Create per-device IOThread if none specified */
         Error *local_err = NULL;
@@ -408,6 +407,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
         s->iothread = iothread_find(vdev->name);
         assert(s->iothread);
     }
+    object_ref(OBJECT(s->iothread));
     s->ctx = iothread_get_aio_context(s->iothread);
 
     /* Prevent block operations that conflict with data plane thread */
-- 
1.8.3.1

Re: [Qemu-devel] [PULL 0/8] Block patches for 2.0.0-rc1

[Peter Maydell]

On 19 March 2014 13:11, Kevin Wolf <kwolf@redhat.com> wrote:
> The following changes since commit 059b3527f0229f4d60fd77a317503d42abd5e50f:
>
>   Merge remote-tracking branch 'remotes/kraxel/tags/pull-vnc-2' into staging (2014-03-18 16:39:29 +0000)
>
> are available in the git repository at:
>
>
>   git://repo.or.cz/qemu/kevin.git tags/for-upstream
>
> for you to fetch changes up to 198fd05c357afff22f0b0e02639937519ed49b1f:
>
>   dataplane: fix implicit IOThread refcount (2014-03-19 09:45:25 +0100)
>
> ----------------------------------------------------------------
> Block patches for 2.0.0-rc1

Applied, thanks.

-- PMM