By acquiring the AioContext we avoid race conditions with the dataplane
thread which may also be accessing the BlockDriverState.
Fix up eject, change, and block_passwd in a single patch because
qmp_eject() and qmp_change_blockdev() both call eject_device(). Also
fix block_passwd while we're tackling a command that takes a block
encryption password.
Signed-off-by: Stefan Hajnoczi stefa...@redhat.com
---
blockdev.c | 36 +---
hw/block/dataplane/virtio-blk.c | 1 +
2 files changed, 30 insertions(+), 7 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index a7f1e09..7bf88d4 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1617,14 +1617,18 @@ exit:
static void eject_device(BlockBackend *blk, int force, Error **errp)
{
BlockDriverState *bs = blk_bs(blk);
+AioContext *aio_context;
+
+aio_context = bdrv_get_aio_context(bs);
+aio_context_acquire(aio_context);
if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
-return;
+goto out;
}
if (!blk_dev_has_removable_media(blk)) {
error_setg(errp, Device '%s' is not removable,
bdrv_get_device_name(bs));
-return;
+goto out;
}
if (blk_dev_is_medium_locked(blk) !blk_dev_is_tray_open(blk)) {
@@ -1632,11 +1636,14 @@ static void eject_device(BlockBackend *blk, int force,
Error **errp)
if (!force) {
error_setg(errp, Device '%s' is locked,
bdrv_get_device_name(bs));
-return;
+goto out;
}
}
bdrv_close(bs);
+
+out:
+aio_context_release(aio_context);
}
void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
@@ -1658,6 +1665,7 @@ void qmp_block_passwd(bool has_device, const char *device,
{
Error *local_err = NULL;
BlockDriverState *bs;
+AioContext *aio_context;
int err;
bs = bdrv_lookup_bs(has_device ? device : NULL,
@@ -1668,16 +1676,23 @@ void qmp_block_passwd(bool has_device, const char
*device,
return;
}
+aio_context = bdrv_get_aio_context(bs);
+aio_context_acquire(aio_context);
+
err = bdrv_set_key(bs, password);
if (err == -EINVAL) {
error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
-return;
+goto out;
} else if (err 0) {
error_set(errp, QERR_INVALID_PASSWORD);
-return;
+goto out;
}
+
+out:
+aio_context_release(aio_context);
}
+/* Assumes AioContext is held */
static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
int bdrv_flags, BlockDriver *drv,
const char *password, Error **errp)
@@ -1710,6 +1725,7 @@ void qmp_change_blockdev(const char *device, const char
*filename,
{
BlockBackend *blk;
BlockDriverState *bs;
+AioContext *aio_context;
BlockDriver *drv = NULL;
int bdrv_flags;
Error *err = NULL;
@@ -1721,24 +1737,30 @@ void qmp_change_blockdev(const char *device, const char
*filename,
}
bs = blk_bs(blk);
+aio_context = bdrv_get_aio_context(bs);
+aio_context_acquire(aio_context);
+
if (format) {
drv = bdrv_find_whitelisted_format(format, bs-read_only);
if (!drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
-return;
+goto out;
}
}
eject_device(blk, 0, err);
if (err) {
error_propagate(errp, err);
-return;
+goto out;
}
bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, errp);
+
+out:
+aio_context_release(aio_context);
}
/* throttling disk I/O limits */
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 5ab64c5..2548113 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -198,6 +198,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev,
VirtIOBlkConf *conf,
blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_DRIVE_DEL, s-blocker);
blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_BACKUP_SOURCE, s-blocker);
blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_COMMIT, s-blocker);
+blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_EJECT, s-blocker);
blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
s-blocker);
blk_op_unblock(conf-conf.blk, BLOCK_OP_TYPE_MIRROR, s-blocker);
--
2.1.0
