[Qemu-devel] [PATCH v4 4/7] block: Add checks of blocker in block operations

[Fam Zheng]

Before operate on a BlockDriverState, respective types are checked
against bs->op_blockers and it will error out if there's a blocker.

Signed-off-by: Fam Zheng <f...@redhat.com>
---
 blockdev-nbd.c |  4 ++++
 blockdev.c     | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 922cf56..c49feae 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -92,6 +92,10 @@ void qmp_nbd_server_add(const char *device, bool 
has_writable, bool writable,
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_NBD_SERVER_ADD, errp)) {
+        return;
+    }
+
     if (!has_writable) {
         writable = false;
     }
diff --git a/blockdev.c b/blockdev.c
index eb55b74..1921d27 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1001,6 +1001,11 @@ SnapshotInfo 
*qmp_blockdev_snapshot_delete_internal_sync(const char *device,
         return NULL;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+                           errp)) {
+        return NULL;
+    }
+
     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
     if (error_is_set(&local_err)) {
         error_propagate(errp, local_err);
@@ -1098,6 +1103,10 @@ static void 
internal_snapshot_prepare(BlkTransactionState *common,
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
+        return;
+    }
+
     if (!bdrv_is_inserted(bs)) {
         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
         return;
@@ -1485,6 +1494,10 @@ void qmp_block_passwd(const char *device, const char 
*password, Error **errp)
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_PASSWD, errp)) {
+        return;
+    }
+
     err = bdrv_set_key(bs, password);
     if (err == -EINVAL) {
         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
@@ -1536,6 +1549,10 @@ void qmp_change_blockdev(const char *device, const char 
*filename,
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
+        return;
+    }
+
     if (format) {
         drv = bdrv_find_whitelisted_format(format, bs->read_only);
         if (!drv) {
@@ -1586,6 +1603,10 @@ void qmp_block_set_io_throttle(const char *device, 
int64_t bps, int64_t bps_rd,
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_SET_IO_THROTTLE, errp)) {
+        return;
+    }
+
     memset(&cfg, 0, sizeof(cfg));
     cfg.buckets[THROTTLE_BPS_TOTAL].avg = bps;
     cfg.buckets[THROTTLE_BPS_READ].avg  = bps_rd;
@@ -1684,6 +1705,10 @@ void qmp_block_resize(const char *device, int64_t size, 
Error **errp)
         return;
     }
 
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, errp)) {
+        return;
+    }
+
     if (size < 0) {
         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
         return;
-- 
1.8.4.2