From: "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com>
Now when you try to migrate with VirtFS export path mounted, you get a proper
QMP error:
(qemu) migrate tcp:localhost:4444
Migration is disabled when VirtFS export path '/tmp/' is mounted in the guest
using mount_tag 'v_tmp'
(qemu)
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
Changes from V1:
We don't depend on TDETACH now, we are yet to finalize how to do the umount
notification. So until we get umount notification, delete migration blocker
on clunk of root fid.
hw/9pfs/virtio-9p-device.c | 22 +++++++++++-----------
hw/9pfs/virtio-9p.c | 19 +++++++++++++++++++
hw/9pfs/virtio-9p.h | 5 +++--
qerror.c | 5 +++++
qerror.h | 3 +++
5 files changed, 41 insertions(+), 13 deletions(-)
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index bba4c54..c9bca8b 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -33,13 +33,15 @@ static V9fsState *to_virtio_9p(VirtIODevice *vdev)
static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
{
+ int len;
struct virtio_9p_config *cfg;
V9fsState *s = to_virtio_9p(vdev);
- cfg = g_malloc0(sizeof(struct virtio_9p_config) +
- s->tag_len);
- stw_raw(&cfg->tag_len, s->tag_len);
- memcpy(cfg->tag, s->tag, s->tag_len);
+ len = strlen(s->tag);
+ cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
+ stw_raw(&cfg->tag_len, len);
+ /* We don't copy the terminating null to config space */
+ memcpy(cfg->tag, s->tag, len);
memcpy(config, cfg, s->config_size);
g_free(cfg);
}
@@ -96,20 +98,18 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf
*conf)
}
len = strlen(conf->tag);
- if (len > MAX_TAG_LEN) {
+ if (len > MAX_TAG_LEN - 1) {
fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
- "maximum (%d bytes)", conf->tag, len, MAX_TAG_LEN);
+ "maximum (%d bytes)", conf->tag, len, MAX_TAG_LEN - 1);
exit(1);
}
- /* s->tag is non-NULL terminated string */
- s->tag = g_malloc(len);
- memcpy(s->tag, conf->tag, len);
- s->tag_len = len;
+
+ s->tag = strdup(conf->tag);
s->ctx.uid = -1;
s->ops = fse->ops;
s->vdev.get_features = virtio_9p_get_features;
- s->config_size = sizeof(struct virtio_9p_config) + s->tag_len;
+ s->config_size = sizeof(struct virtio_9p_config) + len;
s->vdev.get_config = virtio_9p_get_config;
s->fid_list = NULL;
qemu_co_rwlock_init(&s->rename_lock);
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 1b2fc5d..32b98dd 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -23,6 +23,7 @@
#include "virtio-9p-xattr.h"
#include "virtio-9p-coth.h"
#include "trace.h"
+#include "migration.h"
int open_fd_hw;
int total_open_fd;
@@ -373,6 +374,19 @@ static void put_fid(V9fsPDU *pdu, V9fsFidState *fidp)
* Don't free the fid if it is in reclaim list
*/
if (!fidp->ref && fidp->clunked) {
+ if (fidp->fid == pdu->s->root_fid) {
+ /*
+ * if the clunked fid is root fid then we
+ * have unmounted the fs on the client side.
+ * delete the migration blocker. Ideally, this
+ * should be hooked to transport close notification
+ */
+ if (pdu->s->migration_blocker) {
+ migrate_del_blocker(pdu->s->migration_blocker);
+ error_free(pdu->s->migration_blocker);
+ pdu->s->migration_blocker = NULL;
+ }
+ }
free_fid(pdu, fidp);
}
}
@@ -1235,6 +1249,11 @@ static void v9fs_attach(void *opaque)
err = offset;
trace_v9fs_attach_return(pdu->tag, pdu->id,
qid.type, qid.version, qid.path);
+ s->root_fid = fid;
+ /* disable migration */
+ error_set(&s->migration_blocker, QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
+ s->ctx.fs_root, s->tag);
+ migrate_add_blocker(s->migration_blocker);
out:
put_fid(pdu, fidp);
out_nofid:
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index 7f88356..8b612da 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -246,8 +246,7 @@ typedef struct V9fsState
V9fsFidState *fid_list;
FileOperations *ops;
FsContext ctx;
- uint16_t tag_len;
- uint8_t *tag;
+ char *tag;
size_t config_size;
enum p9_proto_version proto_version;
int32_t msize;
@@ -256,6 +255,8 @@ typedef struct V9fsState
* on rename.
*/
CoRwlock rename_lock;
+ int32_t root_fid;
+ Error *migration_blocker;
} V9fsState;
typedef struct V9fsStatState {
diff --git a/qerror.c b/qerror.c
index fdf62b9..25bc91e 100644
--- a/qerror.c
+++ b/qerror.c
@@ -235,6 +235,11 @@ static const QErrorStringTable qerror_table[] = {
"supported by this qemu version: %(feature)",
},
{
+ .error_fmt = QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
+ .desc = "Migration is disabled when VirtFS export path '%(path)' "
+ "is mounted in the guest using mount_tag '%(tag)'",
+ },
+ {
.error_fmt = QERR_VNC_SERVER_FAILED,
.desc = "Could not start VNC server on %(target)",
},
diff --git a/qerror.h b/qerror.h
index 2d3d43b..6414cd9 100644
--- a/qerror.h
+++ b/qerror.h
@@ -192,6 +192,9 @@ QError *qobject_to_qerror(const QObject *obj);
#define QERR_UNKNOWN_BLOCK_FORMAT_FEATURE \
"{ 'class': 'UnknownBlockFormatFeature', 'data': { 'device': %s, 'format':
%s, 'feature': %s } }"
+#define QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION \
+ "{ 'class': 'VirtFSFeatureBlocksMigration', 'data': { 'path': %s, 'tag':
%s } }"
+
#define QERR_VNC_SERVER_FAILED \
"{ 'class': 'VNCServerFailed', 'data': { 'target': %s } }"
--
1.7.5.4
