Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-0…

…7-15' into staging

Block patches for 4.1-rc1:
- Fixes for the NVMe block driver, the gluster block driver, and for
  running multiple block jobs concurrently on a single chain

# gpg: Signature made Mon 15 Jul 2019 14:51:43 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-07-15:
  gluster: fix .bdrv_reopen_prepare when backing file is a JSON object
  iotests: Add read-only test case to 030
  iotests: Add new case to 030
  iotests: Add @use_log to VM.run_job()
  iotests: Compare error messages in 030
  iotests: Fix throttling in 030
  block: Deep-clear inherits_from
  block/stream: Swap backing file change order
  block/stream: Fix error path
  block: Add BDS.never_freeze
  nvme: Set number of queues later in nvme_init()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

block.c

@@ -2472,18 +2472,20 @@ void bdrv_root_unref_child(BdrvChild *child)
     bdrv_unref(child_bs);
 }
 
-void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
+/**
+ * Clear all inherits_from pointers from children and grandchildren of
+ * @root that point to @root, where necessary.
+ */
+static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child)
 {
-    if (child == NULL) {
-        return;
-    }
-
-    if (child->bs->inherits_from == parent) {
-        BdrvChild *c;
+    BdrvChild *c;
 
-        /* Remove inherits_from only when the last reference between parent and
-         * child->bs goes away. */
-        QLIST_FOREACH(c, &parent->children, next) {
+    if (child->bs->inherits_from == root) {
+        /*
+         * Remove inherits_from only when the last reference between root and
+         * child->bs goes away.
+         */
+        QLIST_FOREACH(c, &root->children, next) {
             if (c != child && c->bs == child->bs) {
                 break;
             }
@@ -2493,6 +2495,18 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
         }
     }
 
+    QLIST_FOREACH(c, &child->bs->children, next) {
+        bdrv_unset_inherits_from(root, c);
+    }
+}
+
+void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
+{
+    if (child == NULL) {
+        return;
+    }
+
+    bdrv_unset_inherits_from(parent, child);
     bdrv_root_unref_child(child);
 }
 
@@ -4416,6 +4430,14 @@ int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
         return -EPERM;
     }
 
+    for (i = bs; i != base; i = backing_bs(i)) {
+        if (i->backing && backing_bs(i)->never_freeze) {
+            error_setg(errp, "Cannot freeze '%s' link to '%s'",
+                       i->backing->name, backing_bs(i)->node_name);
+            return -EPERM;
+        }
+    }
+
     for (i = bs; i != base; i = backing_bs(i)) {
         if (i->backing) {
             i->backing->frozen = true;

block/commit.c

@@ -298,6 +298,10 @@ void commit_start(const char *job_id, BlockDriverState *bs,
     if (!filter_node_name) {
         commit_top_bs->implicit = true;
     }
+
+    /* So that we can always drop this node */
+    commit_top_bs->never_freeze = true;
+
     commit_top_bs->total_sectors = top->total_sectors;
 
     bdrv_append(commit_top_bs, top, &local_err);

block/gluster.c

@@ -931,7 +931,17 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
     gconf->has_debug = true;
     gconf->logfile = g_strdup(s->logfile);
     gconf->has_logfile = true;
-    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename, NULL, errp);
+
+    /*
+     * If 'state->bs->exact_filename' is empty, 'state->options' should contain
+     * the JSON parameters already parsed.
+     */
+    if (state->bs->exact_filename[0] != '\0') {
+        reop_s->glfs = qemu_gluster_init(gconf, state->bs->exact_filename, NULL,
+                                         errp);
+    } else {
+        reop_s->glfs = qemu_gluster_init(gconf, NULL, state->options, errp);
+    }
     if (reop_s->glfs == NULL) {
         ret = -errno;
         goto exit;

block/mirror.c

@@ -1551,6 +1551,10 @@ static BlockJob *mirror_start_job(
     if (!filter_node_name) {
         mirror_top_bs->implicit = true;
     }
+
+    /* So that we can always drop this node */
+    mirror_top_bs->never_freeze = true;
+
     mirror_top_bs->total_sectors = bs->total_sectors;
     mirror_top_bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
     mirror_top_bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |

block/nvme.c

@@ -613,12 +613,12 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
 
     /* Set up admin queue. */
     s->queues = g_new(NVMeQueuePair *, 1);
-    s->nr_queues = 1;
     s->queues[0] = nvme_create_queue_pair(bs, 0, NVME_QUEUE_SIZE, errp);
     if (!s->queues[0]) {
         ret = -EINVAL;
         goto out;
     }
+    s->nr_queues = 1;
     QEMU_BUILD_BUG_ON(NVME_QUEUE_SIZE & 0xF000);
     s->regs->aqa = cpu_to_le32((NVME_QUEUE_SIZE << 16) | NVME_QUEUE_SIZE);
     s->regs->asq = cpu_to_le64(s->queues[0]->sq.iova);

block/stream.c

@@ -78,8 +78,8 @@ static int stream_prepare(Job *job)
                 base_fmt = base->drv->format_name;
             }
         }
-        ret = bdrv_change_backing_file(bs, base_id, base_fmt);
         bdrv_set_backing_hd(bs, base, &local_err);
+        ret = bdrv_change_backing_file(bs, base_id, base_fmt);
         if (local_err) {
             error_report_err(local_err);
             return -EPERM;
@@ -284,5 +284,5 @@ void stream_start(const char *job_id, BlockDriverState *bs,
     if (bs_read_only) {
         bdrv_reopen_set_read_only(bs, true, NULL);
     }
-    bdrv_unfreeze_backing_chain(bs, base);
+    bdrv_unfreeze_backing_chain(bs, bottom);
 }

include/block/block_int.h

@@ -885,6 +885,9 @@ struct BlockDriverState {
 
     /* Only read/written by whoever has set active_flush_req to true.  */
     unsigned int flushed_gen;             /* Flushed write generation */
+
+    /* BdrvChild links to this node may never be frozen */
+    bool never_freeze;
 };
 
 struct BlockBackendRootState {