Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-03-14-v2' into queue-block

Block patches for pi day, v2.

# gpg: Signature made Mon Mar 14 17:35:29 2016 CET using RSA key ID E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"

* mreitz/tags/pull-block-for-kevin-2016-03-14-v2:
  iotests: Add test for QMP event rates
  monitor: Use QEMU_CLOCK_VIRTUAL for the event queue in qtest mode
  monitor: Separate QUORUM_REPORT_BAD events according to the node name
  quorum: Fix crash in quorum_aio_cb()
  iotests: Correct 081's reference output
  block: Remove unused typedef of BlockDriverDirtyHandler
  block: Move block dirty bitmap code to separate files
  typedefs: Add BdrvDirtyBitmap
  block: Include hbitmap.h in block.h
  backup: Use Bitmap to replace "s->bitmap"

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

13 files changed, 603 insertions, 413 deletions

diff --git a/block.c b/block.c
index cf5eb34382..59a18a3a66 100644
--- a/block.c
+++ b/block.c
@@ -53,23 +53,6 @@
 #include <windows.h>
 #endif
 
-/**
- * A BdrvDirtyBitmap can be in three possible states:
- * (1) successor is NULL and disabled is false: full r/w mode
- * (2) successor is NULL and disabled is true: read only mode ("disabled")
- * (3) successor is set: frozen mode.
- *     A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
- *     or enabled. A frozen bitmap can only abdicate() or reclaim().
- */
-struct BdrvDirtyBitmap {
-    HBitmap *bitmap;            /* Dirty sector bitmap implementation */
-    BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
-    char *name;                 /* Optional non-empty unique ID */
-    int64_t size;               /* Size of the bitmap (Number of sectors) */
-    bool disabled;              /* Bitmap is read-only */
-    QLIST_ENTRY(BdrvDirtyBitmap) list;
-};
-
 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
 
 struct BdrvStates bdrv_states = QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -88,9 +71,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
                              BlockDriverState *parent,
                              const BdrvChildRole *child_role, Error **errp);
 
-static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
-static void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs);
-
 /* If non-zero, use only whitelisted block drivers */
 static int use_bdrv_whitelist;
 
@@ -3445,346 +3425,6 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked)
     }
 }
 
-BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
-{
-    BdrvDirtyBitmap *bm;
-
-    assert(name);
-    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
-        if (bm->name && !strcmp(name, bm->name)) {
-            return bm;
-        }
-    }
-    return NULL;
-}
-
-void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
-{
-    assert(!bdrv_dirty_bitmap_frozen(bitmap));
-    g_free(bitmap->name);
-    bitmap->name = NULL;
-}
-
-BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
-                                          uint32_t granularity,
-                                          const char *name,
-                                          Error **errp)
-{
-    int64_t bitmap_size;
-    BdrvDirtyBitmap *bitmap;
-    uint32_t sector_granularity;
-
-    assert((granularity & (granularity - 1)) == 0);
-
-    if (name && bdrv_find_dirty_bitmap(bs, name)) {
-        error_setg(errp, "Bitmap already exists: %s", name);
-        return NULL;
-    }
-    sector_granularity = granularity >> BDRV_SECTOR_BITS;
-    assert(sector_granularity);
-    bitmap_size = bdrv_nb_sectors(bs);
-    if (bitmap_size < 0) {
-        error_setg_errno(errp, -bitmap_size, "could not get length of device");
-        errno = -bitmap_size;
-        return NULL;
-    }
-    bitmap = g_new0(BdrvDirtyBitmap, 1);
-    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
-    bitmap->size = bitmap_size;
-    bitmap->name = g_strdup(name);
-    bitmap->disabled = false;
-    QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
-    return bitmap;
-}
-
-bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
-{
-    return bitmap->successor;
-}
-
-bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
-{
-    return !(bitmap->disabled || bitmap->successor);
-}
-
-DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
-{
-    if (bdrv_dirty_bitmap_frozen(bitmap)) {
-        return DIRTY_BITMAP_STATUS_FROZEN;
-    } else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
-        return DIRTY_BITMAP_STATUS_DISABLED;
-    } else {
-        return DIRTY_BITMAP_STATUS_ACTIVE;
-    }
-}
-
-/**
- * Create a successor bitmap destined to replace this bitmap after an operation.
- * Requires that the bitmap is not frozen and has no successor.
- */
-int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
-                                       BdrvDirtyBitmap *bitmap, Error **errp)
-{
-    uint64_t granularity;
-    BdrvDirtyBitmap *child;
-
-    if (bdrv_dirty_bitmap_frozen(bitmap)) {
-        error_setg(errp, "Cannot create a successor for a bitmap that is "
-                   "currently frozen");
-        return -1;
-    }
-    assert(!bitmap->successor);
-
-    /* Create an anonymous successor */
-    granularity = bdrv_dirty_bitmap_granularity(bitmap);
-    child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
-    if (!child) {
-        return -1;
-    }
-
-    /* Successor will be on or off based on our current state. */
-    child->disabled = bitmap->disabled;
-
-    /* Install the successor and freeze the parent */
-    bitmap->successor = child;
-    return 0;
-}
-
-/**
- * For a bitmap with a successor, yield our name to the successor,
- * delete the old bitmap, and return a handle to the new bitmap.
- */
-BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
-                                            BdrvDirtyBitmap *bitmap,
-                                            Error **errp)
-{
-    char *name;
-    BdrvDirtyBitmap *successor = bitmap->successor;
-
-    if (successor == NULL) {
-        error_setg(errp, "Cannot relinquish control if "
-                   "there's no successor present");
-        return NULL;
-    }
-
-    name = bitmap->name;
-    bitmap->name = NULL;
-    successor->name = name;
-    bitmap->successor = NULL;
-    bdrv_release_dirty_bitmap(bs, bitmap);
-
-    return successor;
-}
-
-/**
- * In cases of failure where we can no longer safely delete the parent,
- * we may wish to re-join the parent and child/successor.
- * The merged parent will be un-frozen, but not explicitly re-enabled.
- */
-BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
-                                           BdrvDirtyBitmap *parent,
-                                           Error **errp)
-{
-    BdrvDirtyBitmap *successor = parent->successor;
-
-    if (!successor) {
-        error_setg(errp, "Cannot reclaim a successor when none is present");
-        return NULL;
-    }
-
-    if (!hbitmap_merge(parent->bitmap, successor->bitmap)) {
-        error_setg(errp, "Merging of parent and successor bitmap failed");
-        return NULL;
-    }
-    bdrv_release_dirty_bitmap(bs, successor);
-    parent->successor = NULL;
-
-    return parent;
-}
-
-/**
- * Truncates _all_ bitmaps attached to a BDS.
- */
-static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
-{
-    BdrvDirtyBitmap *bitmap;
-    uint64_t size = bdrv_nb_sectors(bs);
-
-    QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
-        assert(!bdrv_dirty_bitmap_frozen(bitmap));
-        hbitmap_truncate(bitmap->bitmap, size);
-        bitmap->size = size;
-    }
-}
-
-static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
-                                                  BdrvDirtyBitmap *bitmap,
-                                                  bool only_named)
-{
-    BdrvDirtyBitmap *bm, *next;
-    QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
-        if ((!bitmap || bm == bitmap) && (!only_named || bm->name)) {
-            assert(!bdrv_dirty_bitmap_frozen(bm));
-            QLIST_REMOVE(bm, list);
-            hbitmap_free(bm->bitmap);
-            g_free(bm->name);
-            g_free(bm);
-
-            if (bitmap) {
-                return;
-            }
-        }
-    }
-}
-
-void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
-{
-    bdrv_do_release_matching_dirty_bitmap(bs, bitmap, false);
-}
-
-/**
- * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
- * There must not be any frozen bitmaps attached.
- */
-static void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
-{
-    bdrv_do_release_matching_dirty_bitmap(bs, NULL, true);
-}
-
-void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
-{
-    assert(!bdrv_dirty_bitmap_frozen(bitmap));
-    bitmap->disabled = true;
-}
-
-void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
-{
-    assert(!bdrv_dirty_bitmap_frozen(bitmap));
-    bitmap->disabled = false;
-}
-
-BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
-{
-    BdrvDirtyBitmap *bm;
-    BlockDirtyInfoList *list = NULL;
-    BlockDirtyInfoList **plist = &list;
-
-    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
-        BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
-        BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
-        info->count = bdrv_get_dirty_count(bm);
-        info->granularity = bdrv_dirty_bitmap_granularity(bm);
-        info->has_name = !!bm->name;
-        info->name = g_strdup(bm->name);
-        info->status = bdrv_dirty_bitmap_status(bm);
-        entry->value = info;
-        *plist = entry;
-        plist = &entry->next;
-    }
-
-    return list;
-}
-
-int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector)
-{
-    if (bitmap) {
-        return hbitmap_get(bitmap->bitmap, sector);
-    } else {
-        return 0;
-    }
-}
-
-/**
- * Chooses a default granularity based on the existing cluster size,
- * but clamped between [4K, 64K]. Defaults to 64K in the case that there
- * is no cluster size information available.
- */
-uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
-{
-    BlockDriverInfo bdi;
-    uint32_t granularity;
-
-    if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) {
-        granularity = MAX(4096, bdi.cluster_size);
-        granularity = MIN(65536, granularity);
-    } else {
-        granularity = 65536;
-    }
-
-    return granularity;
-}
-
-uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap)
-{
-    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
-}
-
-void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, HBitmapIter *hbi)
-{
-    hbitmap_iter_init(hbi, bitmap->bitmap, 0);
-}
-
-void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                           int64_t cur_sector, int nr_sectors)
-{
-    assert(bdrv_dirty_bitmap_enabled(bitmap));
-    hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
-}
-
-void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                             int64_t cur_sector, int nr_sectors)
-{
-    assert(bdrv_dirty_bitmap_enabled(bitmap));
-    hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
-}
-
-void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
-{
-    assert(bdrv_dirty_bitmap_enabled(bitmap));
-    if (!out) {
-        hbitmap_reset_all(bitmap->bitmap);
-    } else {
-        HBitmap *backup = bitmap->bitmap;
-        bitmap->bitmap = hbitmap_alloc(bitmap->size,
-                                       hbitmap_granularity(backup));
-        *out = backup;
-    }
-}
-
-void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
-{
-    HBitmap *tmp = bitmap->bitmap;
-    assert(bdrv_dirty_bitmap_enabled(bitmap));
-    bitmap->bitmap = in;
-    hbitmap_free(tmp);
-}
-
-void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
-                    int nr_sectors)
-{
-    BdrvDirtyBitmap *bitmap;
-    QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
-        if (!bdrv_dirty_bitmap_enabled(bitmap)) {
-            continue;
-        }
-        hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
-    }
-}
-
-/**
- * Advance an HBitmapIter to an arbitrary offset.
- */
-void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset)
-{
-    assert(hbi->hb);
-    hbitmap_iter_init(hbi, hbi->hb, offset);
-}
-
-int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
-{
-    return hbitmap_count(bitmap->bitmap);
-}
-
 /* Get a reference to bs */
 void bdrv_ref(BlockDriverState *bs)
 {
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 58ef2ef3f2..cdd865597a 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -20,7 +20,7 @@ block-obj-$(CONFIG_RBD) += rbd.o
 block-obj-$(CONFIG_GLUSTERFS) += gluster.o
 block-obj-$(CONFIG_ARCHIPELAGO) += archipelago.o
 block-obj-$(CONFIG_LIBSSH2) += ssh.o
-block-obj-y += accounting.o
+block-obj-y += accounting.o dirty-bitmap.o
 block-obj-y += write-threshold.o
 
 common-obj-y += stream.o
diff --git a/block/backup.c b/block/backup.c
index 0f1b1bc084..ab3e345e92 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -20,6 +20,7 @@
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
 #include "sysemu/block-backend.h"
+#include "qemu/bitmap.h"
 
 #define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
 #define SLICE_TIME 100000000ULL /* ns */
@@ -42,7 +43,7 @@ typedef struct BackupBlockJob {
     BlockdevOnError on_target_error;
     CoRwlock flush_rwlock;
     uint64_t sectors_read;
-    HBitmap *bitmap;
+    unsigned long *done_bitmap;
     int64_t cluster_size;
     QLIST_HEAD(, CowRequest) inflight_reqs;
 } BackupBlockJob;
@@ -116,7 +117,7 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
     cow_request_begin(&cow_request, job, start, end);
 
     for (; start < end; start++) {
-        if (hbitmap_get(job->bitmap, start)) {
+        if (test_bit(start, job->done_bitmap)) {
             trace_backup_do_cow_skip(job, start);
             continue; /* already copied */
         }
@@ -167,7 +168,7 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
             goto out;
         }
 
-        hbitmap_set(job->bitmap, start, 1);
+        set_bit(start, job->done_bitmap);
 
         /* Publish progress, guest I/O counts as progress too.  Note that the
          * offset field is an opaque progress value, it is not a disk offset.
@@ -399,7 +400,7 @@ static void coroutine_fn backup_run(void *opaque)
     start = 0;
     end = DIV_ROUND_UP(job->common.len, job->cluster_size);
 
-    job->bitmap = hbitmap_alloc(end, 0);
+    job->done_bitmap = bitmap_new(end);
 
     bdrv_set_enable_write_cache(target, true);
     if (target->blk) {
@@ -480,7 +481,7 @@ static void coroutine_fn backup_run(void *opaque)
     /* wait until pending backup_do_cow() calls have completed */
     qemu_co_rwlock_wrlock(&job->flush_rwlock);
     qemu_co_rwlock_unlock(&job->flush_rwlock);
-    hbitmap_free(job->bitmap);
+    g_free(job->done_bitmap);
 
     if (target->blk) {
         blk_iostatus_disable(target->blk);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
new file mode 100644
index 0000000000..556e1d15c4
--- /dev/null
+++ b/block/dirty-bitmap.c
@@ -0,0 +1,387 @@
+/*
+ * Block Dirty Bitmap
+ *
+ * Copyright (c) 2016 Red Hat. Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+#include "config-host.h"
+#include "qemu-common.h"
+#include "trace.h"
+#include "block/block_int.h"
+#include "block/blockjob.h"
+
+/**
+ * A BdrvDirtyBitmap can be in three possible states:
+ * (1) successor is NULL and disabled is false: full r/w mode
+ * (2) successor is NULL and disabled is true: read only mode ("disabled")
+ * (3) successor is set: frozen mode.
+ *     A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
+ *     or enabled. A frozen bitmap can only abdicate() or reclaim().
+ */
+struct BdrvDirtyBitmap {
+    HBitmap *bitmap;            /* Dirty sector bitmap implementation */
+    BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
+    char *name;                 /* Optional non-empty unique ID */
+    int64_t size;               /* Size of the bitmap (Number of sectors) */
+    bool disabled;              /* Bitmap is read-only */
+    QLIST_ENTRY(BdrvDirtyBitmap) list;
+};
+
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
+{
+    BdrvDirtyBitmap *bm;
+
+    assert(name);
+    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+        if (bm->name && !strcmp(name, bm->name)) {
+            return bm;
+        }
+    }
+    return NULL;
+}
+
+void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
+{
+    assert(!bdrv_dirty_bitmap_frozen(bitmap));
+    g_free(bitmap->name);
+    bitmap->name = NULL;
+}
+
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+                                          uint32_t granularity,
+                                          const char *name,
+                                          Error **errp)
+{
+    int64_t bitmap_size;
+    BdrvDirtyBitmap *bitmap;
+    uint32_t sector_granularity;
+
+    assert((granularity & (granularity - 1)) == 0);
+
+    if (name && bdrv_find_dirty_bitmap(bs, name)) {
+        error_setg(errp, "Bitmap already exists: %s", name);
+        return NULL;
+    }
+    sector_granularity = granularity >> BDRV_SECTOR_BITS;
+    assert(sector_granularity);
+    bitmap_size = bdrv_nb_sectors(bs);
+    if (bitmap_size < 0) {
+        error_setg_errno(errp, -bitmap_size, "could not get length of device");
+        errno = -bitmap_size;
+        return NULL;
+    }
+    bitmap = g_new0(BdrvDirtyBitmap, 1);
+    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
+    bitmap->size = bitmap_size;
+    bitmap->name = g_strdup(name);
+    bitmap->disabled = false;
+    QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
+    return bitmap;
+}
+
+bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
+{
+    return bitmap->successor;
+}
+
+bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
+{
+    return !(bitmap->disabled || bitmap->successor);
+}
+
+DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
+{
+    if (bdrv_dirty_bitmap_frozen(bitmap)) {
+        return DIRTY_BITMAP_STATUS_FROZEN;
+    } else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
+        return DIRTY_BITMAP_STATUS_DISABLED;
+    } else {
+        return DIRTY_BITMAP_STATUS_ACTIVE;
+    }
+}
+
+/**
+ * Create a successor bitmap destined to replace this bitmap after an operation.
+ * Requires that the bitmap is not frozen and has no successor.
+ */
+int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
+                                       BdrvDirtyBitmap *bitmap, Error **errp)
+{
+    uint64_t granularity;
+    BdrvDirtyBitmap *child;
+
+    if (bdrv_dirty_bitmap_frozen(bitmap)) {
+        error_setg(errp, "Cannot create a successor for a bitmap that is "
+                   "currently frozen");
+        return -1;
+    }
+    assert(!bitmap->successor);
+
+    /* Create an anonymous successor */
+    granularity = bdrv_dirty_bitmap_granularity(bitmap);
+    child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
+    if (!child) {
+        return -1;
+    }
+
+    /* Successor will be on or off based on our current state. */
+    child->disabled = bitmap->disabled;
+
+    /* Install the successor and freeze the parent */
+    bitmap->successor = child;
+    return 0;
+}
+
+/**
+ * For a bitmap with a successor, yield our name to the successor,
+ * delete the old bitmap, and return a handle to the new bitmap.
+ */
+BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
+                                            BdrvDirtyBitmap *bitmap,
+                                            Error **errp)
+{
+    char *name;
+    BdrvDirtyBitmap *successor = bitmap->successor;
+
+    if (successor == NULL) {
+        error_setg(errp, "Cannot relinquish control if "
+                   "there's no successor present");
+        return NULL;
+    }
+
+    name = bitmap->name;
+    bitmap->name = NULL;
+    successor->name = name;
+    bitmap->successor = NULL;
+    bdrv_release_dirty_bitmap(bs, bitmap);
+
+    return successor;
+}
+
+/**
+ * In cases of failure where we can no longer safely delete the parent,
+ * we may wish to re-join the parent and child/successor.
+ * The merged parent will be un-frozen, but not explicitly re-enabled.
+ */
+BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
+                                           BdrvDirtyBitmap *parent,
+                                           Error **errp)
+{
+    BdrvDirtyBitmap *successor = parent->successor;
+
+    if (!successor) {
+        error_setg(errp, "Cannot reclaim a successor when none is present");
+        return NULL;
+    }
+
+    if (!hbitmap_merge(parent->bitmap, successor->bitmap)) {
+        error_setg(errp, "Merging of parent and successor bitmap failed");
+        return NULL;
+    }
+    bdrv_release_dirty_bitmap(bs, successor);
+    parent->successor = NULL;
+
+    return parent;
+}
+
+/**
+ * Truncates _all_ bitmaps attached to a BDS.
+ */
+void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
+{
+    BdrvDirtyBitmap *bitmap;
+    uint64_t size = bdrv_nb_sectors(bs);
+
+    QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
+        assert(!bdrv_dirty_bitmap_frozen(bitmap));
+        hbitmap_truncate(bitmap->bitmap, size);
+        bitmap->size = size;
+    }
+}
+
+static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
+                                                  BdrvDirtyBitmap *bitmap,
+                                                  bool only_named)
+{
+    BdrvDirtyBitmap *bm, *next;
+    QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
+        if ((!bitmap || bm == bitmap) && (!only_named || bm->name)) {
+            assert(!bdrv_dirty_bitmap_frozen(bm));
+            QLIST_REMOVE(bm, list);
+            hbitmap_free(bm->bitmap);
+            g_free(bm->name);
+            g_free(bm);
+
+            if (bitmap) {
+                return;
+            }
+        }
+    }
+}
+
+void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
+{
+    bdrv_do_release_matching_dirty_bitmap(bs, bitmap, false);
+}
+
+/**
+ * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
+ * There must not be any frozen bitmaps attached.
+ */
+void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
+{
+    bdrv_do_release_matching_dirty_bitmap(bs, NULL, true);
+}
+
+void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+    assert(!bdrv_dirty_bitmap_frozen(bitmap));
+    bitmap->disabled = true;
+}
+
+void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+    assert(!bdrv_dirty_bitmap_frozen(bitmap));
+    bitmap->disabled = false;
+}
+
+BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
+{
+    BdrvDirtyBitmap *bm;
+    BlockDirtyInfoList *list = NULL;
+    BlockDirtyInfoList **plist = &list;
+
+    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+        BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
+        BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
+        info->count = bdrv_get_dirty_count(bm);
+        info->granularity = bdrv_dirty_bitmap_granularity(bm);
+        info->has_name = !!bm->name;
+        info->name = g_strdup(bm->name);
+        info->status = bdrv_dirty_bitmap_status(bm);
+        entry->value = info;
+        *plist = entry;
+        plist = &entry->next;
+    }
+
+    return list;
+}
+
+int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                   int64_t sector)
+{
+    if (bitmap) {
+        return hbitmap_get(bitmap->bitmap, sector);
+    } else {
+        return 0;
+    }
+}
+
+/**
+ * Chooses a default granularity based on the existing cluster size,
+ * but clamped between [4K, 64K]. Defaults to 64K in the case that there
+ * is no cluster size information available.
+ */
+uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
+{
+    BlockDriverInfo bdi;
+    uint32_t granularity;
+
+    if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) {
+        granularity = MAX(4096, bdi.cluster_size);
+        granularity = MIN(65536, granularity);
+    } else {
+        granularity = 65536;
+    }
+
+    return granularity;
+}
+
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap)
+{
+    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
+}
+
+void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, HBitmapIter *hbi)
+{
+    hbitmap_iter_init(hbi, bitmap->bitmap, 0);
+}
+
+void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                           int64_t cur_sector, int nr_sectors)
+{
+    assert(bdrv_dirty_bitmap_enabled(bitmap));
+    hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                             int64_t cur_sector, int nr_sectors)
+{
+    assert(bdrv_dirty_bitmap_enabled(bitmap));
+    hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
+{
+    assert(bdrv_dirty_bitmap_enabled(bitmap));
+    if (!out) {
+        hbitmap_reset_all(bitmap->bitmap);
+    } else {
+        HBitmap *backup = bitmap->bitmap;
+        bitmap->bitmap = hbitmap_alloc(bitmap->size,
+                                       hbitmap_granularity(backup));
+        *out = backup;
+    }
+}
+
+void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
+{
+    HBitmap *tmp = bitmap->bitmap;
+    assert(bdrv_dirty_bitmap_enabled(bitmap));
+    bitmap->bitmap = in;
+    hbitmap_free(tmp);
+}
+
+void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
+                    int nr_sectors)
+{
+    BdrvDirtyBitmap *bitmap;
+    QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
+        if (!bdrv_dirty_bitmap_enabled(bitmap)) {
+            continue;
+        }
+        hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+    }
+}
+
+/**
+ * Advance an HBitmapIter to an arbitrary offset.
+ */
+void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset)
+{
+    assert(hbi->hb);
+    hbitmap_iter_init(hbi, hbi->hb, offset);
+}
+
+int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
+{
+    return hbitmap_count(bitmap->bitmap);
+}
diff --git a/block/quorum.c b/block/quorum.c
index b16171b57e..3d473515a8 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -655,8 +655,9 @@ static BlockAIOCB *read_quorum_children(QuorumAIOCB *acb)
     }
 
     for (i = 0; i < s->num_children; i++) {
-        bdrv_aio_readv(s->children[i]->bs, acb->sector_num, &acb->qcrs[i].qiov,
-                       acb->nb_sectors, quorum_aio_cb, &acb->qcrs[i]);
+        acb->qcrs[i].aiocb = bdrv_aio_readv(s->children[i]->bs, acb->sector_num,
+                                            &acb->qcrs[i].qiov, acb->nb_sectors,
+                                            quorum_aio_cb, &acb->qcrs[i]);
     }
 
     return &acb->common;
@@ -671,9 +672,10 @@ static BlockAIOCB *read_fifo_child(QuorumAIOCB *acb)
     qemu_iovec_init(&acb->qcrs[acb->child_iter].qiov, acb->qiov->niov);
     qemu_iovec_clone(&acb->qcrs[acb->child_iter].qiov, acb->qiov,
                      acb->qcrs[acb->child_iter].buf);
-    bdrv_aio_readv(s->children[acb->child_iter]->bs, acb->sector_num,
-                   &acb->qcrs[acb->child_iter].qiov, acb->nb_sectors,
-                   quorum_aio_cb, &acb->qcrs[acb->child_iter]);
+    acb->qcrs[acb->child_iter].aiocb =
+        bdrv_aio_readv(s->children[acb->child_iter]->bs, acb->sector_num,
+                       &acb->qcrs[acb->child_iter].qiov, acb->nb_sectors,
+                       quorum_aio_cb, &acb->qcrs[acb->child_iter]);
 
     return &acb->common;
 }
diff --git a/include/block/block.h b/include/block/block.h
index 3900c4d8c3..eaa64262d9 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -6,8 +6,10 @@
 #include "qemu/option.h"
 #include "qemu/coroutine.h"
 #include "block/accounting.h"
+#include "block/dirty-bitmap.h"
 #include "qapi/qmp/qobject.h"
 #include "qapi-types.h"
+#include "qemu/hbitmap.h"
 
 /* block.c */
 typedef struct BlockDriver BlockDriver;
@@ -319,8 +321,6 @@ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
                                         const char *node_name, Error **errp);
 
 /* async block I/O */
-typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
-                                     int sector_num);
 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
                            QEMUIOVector *iov, int nb_sectors,
                            BlockCompletionFunc *cb, void *opaque);
@@ -474,42 +474,6 @@ void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 
-struct HBitmapIter;
-typedef struct BdrvDirtyBitmap BdrvDirtyBitmap;
-BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
-                                          uint32_t granularity,
-                                          const char *name,
-                                          Error **errp);
-int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
-                                       BdrvDirtyBitmap *bitmap,
-                                       Error **errp);
-BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
-                                            BdrvDirtyBitmap *bitmap,
-                                            Error **errp);
-BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
-                                           BdrvDirtyBitmap *bitmap,
-                                           Error **errp);
-BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
-                                        const char *name);
-void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap);
-void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
-void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
-void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
-BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
-uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs);
-uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap);
-bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap);
-bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap);
-DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap);
-int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector);
-void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                           int64_t cur_sector, int nr_sectors);
-void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
-                             int64_t cur_sector, int nr_sectors);
-void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi);
-void bdrv_set_dirty_iter(struct HBitmapIter *hbi, int64_t offset);
-int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
-
 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
new file mode 100644
index 0000000000..80afe603f6
--- /dev/null
+++ b/include/block/dirty-bitmap.h
@@ -0,0 +1,44 @@
+#ifndef BLOCK_DIRTY_BITMAP_H
+#define BLOCK_DIRTY_BITMAP_H
+
+#include "qemu-common.h"
+#include "qemu/hbitmap.h"
+
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+                                          uint32_t granularity,
+                                          const char *name,
+                                          Error **errp);
+int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
+                                       BdrvDirtyBitmap *bitmap,
+                                       Error **errp);
+BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
+                                            BdrvDirtyBitmap *bitmap,
+                                            Error **errp);
+BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
+                                           BdrvDirtyBitmap *bitmap,
+                                           Error **errp);
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
+                                        const char *name);
+void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap);
+void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
+void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs);
+void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
+void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
+BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
+uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs);
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap);
+DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap);
+int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                   int64_t sector);
+void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                           int64_t cur_sector, int nr_sectors);
+void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                             int64_t cur_sector, int nr_sectors);
+void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi);
+void bdrv_set_dirty_iter(struct HBitmapIter *hbi, int64_t offset);
+int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
+void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
+
+#endif
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 9a5ead69a1..fd039e0e81 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -10,6 +10,7 @@ typedef struct AddressSpace AddressSpace;
 typedef struct AioContext AioContext;
 typedef struct AllwinnerAHCIState AllwinnerAHCIState;
 typedef struct AudioState AudioState;
+typedef struct BdrvDirtyBitmap BdrvDirtyBitmap;
 typedef struct BlockBackend BlockBackend;
 typedef struct BlockBackendRootState BlockBackendRootState;
 typedef struct BlockDriverState BlockDriverState;
diff --git a/monitor.c b/monitor.c
index e99ca8c91e..894f862dd3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -76,6 +76,7 @@
 #include "qapi-event.h"
 #include "qmp-introspect.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/qtest.h"
 
 /* for hmp_info_irq/pic */
 #if defined(TARGET_SPARC)
@@ -232,6 +233,8 @@ static const mon_cmd_t qmp_cmds[];
 
 Monitor *cur_mon;
 
+static QEMUClockType event_clock_type = QEMU_CLOCK_REALTIME;
+
 static void monitor_command_cb(void *opaque, const char *cmdline,
                                void *readline_opaque);
 
@@ -513,7 +516,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp)
              * monitor_qapi_event_handler() in evconf->rate ns.  Any
              * events arriving before then will be delayed until then.
              */
-            int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+            int64_t now = qemu_clock_get_ns(event_clock_type);
 
             monitor_qapi_event_emit(event, qdict);
 
@@ -522,7 +525,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp)
             evstate->data = data;
             QINCREF(evstate->data);
             evstate->qdict = NULL;
-            evstate->timer = timer_new_ns(QEMU_CLOCK_REALTIME,
+            evstate->timer = timer_new_ns(event_clock_type,
                                           monitor_qapi_event_handler,
                                           evstate);
             g_hash_table_add(monitor_qapi_event_state, evstate);
@@ -547,7 +550,7 @@ static void monitor_qapi_event_handler(void *opaque)
     qemu_mutex_lock(&monitor_lock);
 
     if (evstate->qdict) {
-        int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+        int64_t now = qemu_clock_get_ns(event_clock_type);
 
         monitor_qapi_event_emit(evstate->event, evstate->qdict);
         QDECREF(evstate->qdict);
@@ -572,6 +575,10 @@ static unsigned int qapi_event_throttle_hash(const void *key)
         hash += g_str_hash(qdict_get_str(evstate->data, "id"));
     }
 
+    if (evstate->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
+        hash += g_str_hash(qdict_get_str(evstate->data, "node-name"));
+    }
+
     return hash;
 }
 
@@ -589,11 +596,20 @@ static gboolean qapi_event_throttle_equal(const void *a, const void *b)
                        qdict_get_str(evb->data, "id"));
     }
 
+    if (eva->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
+        return !strcmp(qdict_get_str(eva->data, "node-name"),
+                       qdict_get_str(evb->data, "node-name"));
+    }
+
     return TRUE;
 }
 
 static void monitor_qapi_event_init(void)
 {
+    if (qtest_enabled()) {
+        event_clock_type = QEMU_CLOCK_VIRTUAL;
+    }
+
     monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash,
                                                 qapi_event_throttle_equal);
     qmp_event_set_func_emit(monitor_qapi_event_queue);
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 70632314c8..97df69d71c 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -31,7 +31,7 @@ QMP_VERSION
 {"return": {}}
 {"return": {}}
 {"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "QUORUM_REPORT_BAD", "data": {"node-name": "drive2", "sectors-count": 20480, "sector-num": 0}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "QUORUM_REPORT_BAD", "data": {"node-name": "drive2", "sectors-count": 20480, "sector-num": 0, "type": "read"}}
 read 10485760/10485760 bytes at offset 0
 10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": ""}
diff --git a/tests/qemu-iotests/148 b/tests/qemu-iotests/148
new file mode 100644
index 0000000000..30bc37958e
--- /dev/null
+++ b/tests/qemu-iotests/148
@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+#
+# Test the rate limit of QMP events
+#
+# Copyright (C) 2016 Igalia, S.L.
+# Author: Alberto Garcia <berto@igalia.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import os
+import iotests
+
+imgs = (os.path.join(iotests.test_dir, 'quorum0.img'),
+        os.path.join(iotests.test_dir, 'quorum1.img'),
+        os.path.join(iotests.test_dir, 'quorum2.img'))
+
+img_conf = (os.path.join(iotests.test_dir, 'quorum0.conf'),
+            os.path.join(iotests.test_dir, 'quorum1.conf'),
+            os.path.join(iotests.test_dir, 'quorum2.conf'))
+
+event_rate = 1000000000
+sector_size = 512
+offset = 10
+
+class TestQuorumEvents(iotests.QMPTestCase):
+
+    def create_blkdebug_file(self, blkdebug_file, bad_sector):
+        file = open(blkdebug_file, 'w')
+        file.write('''
+[inject-error]
+event = "read_aio"
+errno = "5"
+sector = "%d"
+''' % bad_sector)
+        file.close()
+
+    def setUp(self):
+        driveopts = ['driver=quorum', 'vote-threshold=2']
+        for i in range(len(imgs)):
+            iotests.qemu_img('create', '-f', iotests.imgfmt, imgs[i], '1M')
+            self.create_blkdebug_file(img_conf[i], i + offset)
+            driveopts.append('children.%d.driver=%s' % (i, iotests.imgfmt))
+            driveopts.append('children.%d.file.driver=blkdebug' % i)
+            driveopts.append('children.%d.file.config=%s' % (i, img_conf[i]))
+            driveopts.append('children.%d.file.image.filename=%s' % (i, imgs[i]))
+            driveopts.append('children.%d.node-name=img%d' % (i, i))
+        self.vm = iotests.VM()
+        self.vm.add_drive(None, opts = ','.join(driveopts))
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        for i in range(len(imgs)):
+            os.remove(imgs[i])
+            os.remove(img_conf[i])
+
+    def do_check_event(self, node, sector = 0):
+        if node == None:
+            self.assertEqual(self.vm.get_qmp_event(), None)
+            return
+
+        for event in self.vm.get_qmp_events(wait=True):
+            if event['event'] == 'QUORUM_REPORT_BAD':
+                self.assert_qmp(event, 'data/node-name', node)
+                self.assert_qmp(event, 'data/sector-num', sector)
+
+    def testQuorum(self):
+        if not 'quorum' in iotests.qemu_img_pipe('--help'):
+            return
+
+        # Generate an error and get an event
+        self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                            (offset * sector_size, sector_size))
+        self.vm.qtest("clock_step 10")
+        self.do_check_event('img0', offset)
+
+        # I/O errors in the same child: only one event is emitted
+        delay = 10
+        for i in range(3):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                (offset * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event(None)
+
+        # Wait enough so the event is finally emitted
+        self.vm.qtest("clock_step %d" % (2 * event_rate))
+        self.do_check_event('img0', offset)
+
+        # I/O errors in the same child: all events are emitted
+        delay = 2 * event_rate
+        for i in range(3):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                (offset * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img0', offset)
+
+        # I/O errors in different children: all events are emitted
+        delay = 10
+        for i in range(len(imgs)):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                ((offset + i) * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img%d' % i, offset + i)
+
+        # I/O errors in different children: all events are emitted
+        delay = 2 * event_rate
+        for i in range(len(imgs)):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                ((offset + i) * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img%d' % i, offset + i)
+
+        # No more pending events
+        self.do_check_event(None)
+
+if __name__ == '__main__':
+    iotests.main(supported_fmts=["raw"])
diff --git a/tests/qemu-iotests/148.out b/tests/qemu-iotests/148.out
new file mode 100644
index 0000000000..ae1213e6f8
--- /dev/null
+++ b/tests/qemu-iotests/148.out
@@ -0,0 +1,5 @@
+.
+----------------------------------------------------------------------
+Ran 1 tests
+
+OK
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 1211149249..faf0f21397 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -149,3 +149,4 @@
 144 rw auto quick
 145 auto quick
 146 auto quick
+148 rw auto quick