X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=block.c;h=a387c1ad684a34208620e723004374880bda5027;hb=bc72ad67543f5c5d39c005ff0ca72da37642a1fb;hp=4ad663d3fae8e75e4c3eeddd5f6fc516bc8b3554;hpb=4ceb193d30fe9b1cda0dc73bddb8051659926fb9;p=qemu.git

diff --git a/block.c b/block.c
index 4ad663d3f..a387c1ad6 100644
--- a/block.c
+++ b/block.c
@@ -99,9 +99,6 @@ static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
     QLIST_HEAD_INITIALIZER(bdrv_drivers);
 
-/* The device to use for VM snapshots */
-static BlockDriverState *bs_snapshots;
-
 /* If non-zero, use only whitelisted block drivers */
 static int use_bdrv_whitelist;
 
@@ -130,11 +127,11 @@ void bdrv_io_limits_disable(BlockDriverState *bs)
 {
     bs->io_limits_enabled = false;
 
-    while (qemu_co_queue_next(&bs->throttled_reqs));
+    do {} while (qemu_co_enter_next(&bs->throttled_reqs));
 
     if (bs->block_timer) {
-        qemu_del_timer(bs->block_timer);
-        qemu_free_timer(bs->block_timer);
+        timer_del(bs->block_timer);
+        timer_free(bs->block_timer);
         bs->block_timer = NULL;
     }
 
@@ -146,13 +143,12 @@ static void bdrv_block_timer(void *opaque)
 {
     BlockDriverState *bs = opaque;
 
-    qemu_co_queue_next(&bs->throttled_reqs);
+    qemu_co_enter_next(&bs->throttled_reqs);
 }
 
 void bdrv_io_limits_enable(BlockDriverState *bs)
 {
-    qemu_co_queue_init(&bs->throttled_reqs);
-    bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs);
+    bs->block_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, bdrv_block_timer, bs);
     bs->io_limits_enabled = true;
 }
 
@@ -184,8 +180,8 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
      */
 
     while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) {
-        qemu_mod_timer(bs->block_timer,
-                       wait_time + qemu_get_clock_ns(vm_clock));
+        timer_mod(bs->block_timer,
+                       wait_time + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
         qemu_co_queue_wait_insert_head(&bs->throttled_reqs);
     }
 
@@ -308,6 +304,8 @@ BlockDriverState *bdrv_new(const char *device_name)
     }
     bdrv_iostatus_disable(bs);
     notifier_list_init(&bs->close_notifiers);
+    notifier_with_return_list_init(&bs->before_write_notifiers);
+    qemu_co_queue_init(&bs->throttled_reqs);
 
     return bs;
 }
@@ -328,28 +326,40 @@ BlockDriver *bdrv_find_format(const char *format_name)
     return NULL;
 }
 
-static int bdrv_is_whitelisted(BlockDriver *drv)
+static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
 {
-    static const char *whitelist[] = {
-        CONFIG_BDRV_WHITELIST
+    static const char *whitelist_rw[] = {
+        CONFIG_BDRV_RW_WHITELIST
+    };
+    static const char *whitelist_ro[] = {
+        CONFIG_BDRV_RO_WHITELIST
     };
     const char **p;
 
-    if (!whitelist[0])
+    if (!whitelist_rw[0] && !whitelist_ro[0]) {
         return 1;               /* no whitelist, anything goes */
+    }
 
-    for (p = whitelist; *p; p++) {
+    for (p = whitelist_rw; *p; p++) {
         if (!strcmp(drv->format_name, *p)) {
             return 1;
         }
     }
+    if (read_only) {
+        for (p = whitelist_ro; *p; p++) {
+            if (!strcmp(drv->format_name, *p)) {
+                return 1;
+            }
+        }
+    }
     return 0;
 }
 
-BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
+BlockDriver *bdrv_find_whitelisted_format(const char *format_name,
+                                          bool read_only)
 {
     BlockDriver *drv = bdrv_find_format(format_name);
-    return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
+    return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL;
 }
 
 typedef struct CreateCo {
@@ -407,7 +417,7 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
 {
     BlockDriver *drv;
 
-    drv = bdrv_find_protocol(filename);
+    drv = bdrv_find_protocol(filename, true);
     if (drv == NULL) {
         return -ENOENT;
     }
@@ -472,7 +482,8 @@ static BlockDriver *find_hdev_driver(const char *filename)
     return drv;
 }
 
-BlockDriver *bdrv_find_protocol(const char *filename)
+BlockDriver *bdrv_find_protocol(const char *filename,
+                                bool allow_protocol_prefix)
 {
     BlockDriver *drv1;
     char protocol[128];
@@ -493,9 +504,10 @@ BlockDriver *bdrv_find_protocol(const char *filename)
         return drv1;
     }
 
-    if (!path_has_protocol(filename)) {
+    if (!path_has_protocol(filename) || !allow_protocol_prefix) {
         return bdrv_find_format("file");
     }
+
     p = strchr(filename, ':');
     assert(p != NULL);
     len = p - filename;
@@ -667,21 +679,23 @@ static int bdrv_open_flags(BlockDriverState *bs, int flags)
  * Removes all processed options from *options.
  */
 static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
-    const char *filename, QDict *options,
-    int flags, BlockDriver *drv)
+    QDict *options, int flags, BlockDriver *drv)
 {
     int ret, open_flags;
+    const char *filename;
 
     assert(drv != NULL);
     assert(bs->file == NULL);
     assert(options != NULL && bs->options != options);
 
-    trace_bdrv_open_common(bs, filename, flags, drv->format_name);
-
-    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
-        return -ENOTSUP;
+    if (file != NULL) {
+        filename = file->filename;
+    } else {
+        filename = qdict_get_try_str(options, "filename");
     }
 
+    trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
+
     /* bdrv_open() with directly using a protocol as drv. This layer is already
      * opened, so assign it to bs (while file becomes a closed BlockDriverState)
      * and return immediately. */
@@ -692,9 +706,16 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
 
     bs->open_flags = flags;
     bs->buffer_alignment = 512;
+    bs->zero_beyond_eof = true;
+    open_flags = bdrv_open_flags(bs, flags);
+    bs->read_only = !(open_flags & BDRV_O_RDWR);
+
+    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
+        return -ENOTSUP;
+    }
 
     assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
-    if ((flags & BDRV_O_RDWR) && (flags & BDRV_O_COPY_ON_READ)) {
+    if (!bs->read_only && (flags & BDRV_O_COPY_ON_READ)) {
         bdrv_enable_copy_on_read(bs);
     }
 
@@ -708,16 +729,20 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     bs->opaque = g_malloc0(drv->instance_size);
 
     bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
-    open_flags = bdrv_open_flags(bs, flags);
-
-    bs->read_only = !(open_flags & BDRV_O_RDWR);
 
     /* Open the image, either directly or using a protocol */
     if (drv->bdrv_file_open) {
         assert(file == NULL);
         assert(drv->bdrv_parse_filename || filename != NULL);
-        ret = drv->bdrv_file_open(bs, filename, options, open_flags);
+        ret = drv->bdrv_file_open(bs, options, open_flags);
     } else {
+        if (file == NULL) {
+            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't use '%s' as a "
+                          "block driver for the protocol level",
+                          drv->format_name);
+            ret = -EINVAL;
+            goto free_and_fail;
+        }
         assert(file != NULL);
         bs->file = file;
         ret = drv->bdrv_open(bs, options, open_flags);
@@ -762,6 +787,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
     BlockDriverState *bs;
     BlockDriver *drv;
     const char *drvname;
+    bool allow_protocol_prefix = false;
     int ret;
 
     /* NULL means an empty set of options */
@@ -773,13 +799,29 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
     bs->options = options;
     options = qdict_clone_shallow(options);
 
+    /* Fetch the file name from the options QDict if necessary */
+    if (!filename) {
+        filename = qdict_get_try_str(options, "filename");
+    } else if (filename && !qdict_haskey(options, "filename")) {
+        qdict_put(options, "filename", qstring_from_str(filename));
+        allow_protocol_prefix = true;
+    } else {
+        qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't specify 'file' and "
+                      "'filename' options at the same time");
+        ret = -EINVAL;
+        goto fail;
+    }
+
     /* Find the right block driver */
     drvname = qdict_get_try_str(options, "driver");
     if (drvname) {
-        drv = bdrv_find_whitelisted_format(drvname);
+        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
         qdict_del(options, "driver");
     } else if (filename) {
-        drv = bdrv_find_protocol(filename);
+        drv = bdrv_find_protocol(filename, allow_protocol_prefix);
+        if (!drv) {
+            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Unknown protocol");
+        }
     } else {
         qerror_report(ERROR_CLASS_GENERIC_ERROR,
                       "Must specify either driver or file");
@@ -801,6 +843,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
             ret = -EINVAL;
             goto fail;
         }
+        qdict_del(options, "filename");
     } else if (!drv->bdrv_parse_filename && !filename) {
         qerror_report(ERROR_CLASS_GENERIC_ERROR,
                       "The '%s' block driver requires a file name",
@@ -809,7 +852,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
         goto fail;
     }
 
-    ret = bdrv_open_common(bs, NULL, filename, options, flags, drv);
+    ret = bdrv_open_common(bs, NULL, options, flags, drv);
     if (ret < 0) {
         goto fail;
     }
@@ -838,18 +881,35 @@ fail:
     return ret;
 }
 
-int bdrv_open_backing_file(BlockDriverState *bs)
+/*
+ * Opens the backing file for a BlockDriverState if not yet open
+ *
+ * options is a QDict of options to pass to the block drivers, or NULL for an
+ * empty set of options. The reference to the QDict is transferred to this
+ * function (even on failure), so if the caller intends to reuse the dictionary,
+ * it needs to use QINCREF() before calling bdrv_file_open.
+ */
+int bdrv_open_backing_file(BlockDriverState *bs, QDict *options)
 {
     char backing_filename[PATH_MAX];
     int back_flags, ret;
     BlockDriver *back_drv = NULL;
 
     if (bs->backing_hd != NULL) {
+        QDECREF(options);
         return 0;
     }
 
+    /* NULL means an empty set of options */
+    if (options == NULL) {
+        options = qdict_new();
+    }
+
     bs->open_flags &= ~BDRV_O_NO_BACKING;
-    if (bs->backing_file[0] == '\0') {
+    if (qdict_haskey(options, "file.filename")) {
+        backing_filename[0] = '\0';
+    } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
+        QDECREF(options);
         return 0;
     }
 
@@ -864,7 +924,8 @@ int bdrv_open_backing_file(BlockDriverState *bs)
     /* backing files always opened read-only */
     back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT);
 
-    ret = bdrv_open(bs->backing_hd, backing_filename, NULL,
+    ret = bdrv_open(bs->backing_hd,
+                    *backing_filename ? backing_filename : NULL, options,
                     back_flags, back_drv);
     if (ret < 0) {
         bdrv_delete(bs->backing_hd);
@@ -910,6 +971,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     char tmp_filename[PATH_MAX + 1];
     BlockDriverState *file = NULL;
     QDict *file_options = NULL;
+    const char *drvname;
 
     /* NULL means an empty set of options */
     if (options == NULL) {
@@ -993,12 +1055,18 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     extract_subqdict(options, &file_options, "file.");
 
     ret = bdrv_file_open(&file, filename, file_options,
-                         bdrv_open_flags(bs, flags));
+                         bdrv_open_flags(bs, flags | BDRV_O_UNMAP));
     if (ret < 0) {
         goto fail;
     }
 
     /* Find the right image format driver */
+    drvname = qdict_get_try_str(options, "driver");
+    if (drvname) {
+        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
+        qdict_del(options, "driver");
+    }
+
     if (!drv) {
         ret = find_image_format(file, filename, &drv);
     }
@@ -1008,7 +1076,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     }
 
     /* Open the image */
-    ret = bdrv_open_common(bs, file, filename, options, flags, drv);
+    ret = bdrv_open_common(bs, file, options, flags, drv);
     if (ret < 0) {
         goto unlink_and_fail;
     }
@@ -1020,7 +1088,10 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
 
     /* If there is a backing file, use it */
     if ((flags & BDRV_O_NO_BACKING) == 0) {
-        ret = bdrv_open_backing_file(bs);
+        QDict *backing_options;
+
+        extract_subqdict(options, &backing_options, "backing.");
+        ret = bdrv_open_backing_file(bs, backing_options);
         if (ret < 0) {
             goto close_and_fail;
         }
@@ -1236,8 +1307,8 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
             if (local_err != NULL) {
                 error_propagate(errp, local_err);
             } else {
-                error_set(errp, QERR_OPEN_FILE_FAILED,
-                          reopen_state->bs->filename);
+                error_setg(errp, "failed while preparing to reopen image '%s'",
+                           reopen_state->bs->filename);
             }
             goto error;
         }
@@ -1302,17 +1373,15 @@ void bdrv_reopen_abort(BDRVReopenState *reopen_state)
 
 void bdrv_close(BlockDriverState *bs)
 {
-    bdrv_flush(bs);
     if (bs->job) {
         block_job_cancel_sync(bs->job);
     }
-    bdrv_drain_all();
+    bdrv_drain_all(); /* complete I/O */
+    bdrv_flush(bs);
+    bdrv_drain_all(); /* in case flush left pending I/O */
     notifier_list_notify(&bs->close_notifiers, bs);
 
     if (bs->drv) {
-        if (bs == bs_snapshots) {
-            bs_snapshots = NULL;
-        }
         if (bs->backing_hd) {
             bdrv_delete(bs->backing_hd);
             bs->backing_hd = NULL;
@@ -1334,6 +1403,7 @@ void bdrv_close(BlockDriverState *bs)
         bs->valid_key = 0;
         bs->sg = 0;
         bs->growable = 0;
+        bs->zero_beyond_eof = false;
         QDECREF(bs->options);
         bs->options = NULL;
 
@@ -1360,6 +1430,35 @@ void bdrv_close_all(void)
     }
 }
 
+/* Check if any requests are in-flight (including throttled requests) */
+static bool bdrv_requests_pending(BlockDriverState *bs)
+{
+    if (!QLIST_EMPTY(&bs->tracked_requests)) {
+        return true;
+    }
+    if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+        return true;
+    }
+    if (bs->file && bdrv_requests_pending(bs->file)) {
+        return true;
+    }
+    if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
+        return true;
+    }
+    return false;
+}
+
+static bool bdrv_requests_pending_all(void)
+{
+    BlockDriverState *bs;
+    QTAILQ_FOREACH(bs, &bdrv_states, list) {
+        if (bdrv_requests_pending(bs)) {
+            return true;
+        }
+    }
+    return false;
+}
+
 /*
  * Wait for pending requests to complete across all BlockDriverStates
  *
@@ -1374,27 +1473,22 @@ void bdrv_close_all(void)
  */
 void bdrv_drain_all(void)
 {
+    /* Always run first iteration so any pending completion BHs run */
+    bool busy = true;
     BlockDriverState *bs;
-    bool busy;
-
-    do {
-        busy = qemu_aio_wait();
 
+    while (busy) {
         /* FIXME: We do not have timer support here, so this is effectively
          * a busy wait.
          */
         QTAILQ_FOREACH(bs, &bdrv_states, list) {
-            if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
-                qemu_co_queue_restart_all(&bs->throttled_reqs);
+            while (qemu_co_enter_next(&bs->throttled_reqs)) {
                 busy = true;
             }
         }
-    } while (busy);
 
-    /* If requests are still pending there is a bug somewhere */
-    QTAILQ_FOREACH(bs, &bdrv_states, list) {
-        assert(QLIST_EMPTY(&bs->tracked_requests));
-        assert(qemu_co_queue_empty(&bs->throttled_reqs));
+        busy = bdrv_requests_pending_all();
+        busy |= aio_poll(qemu_get_aio_context(), busy);
     }
 }
 
@@ -1539,12 +1633,11 @@ void bdrv_delete(BlockDriverState *bs)
     assert(!bs->job);
     assert(!bs->in_use);
 
+    bdrv_close(bs);
+
     /* remove from list, if necessary */
     bdrv_make_anon(bs);
 
-    bdrv_close(bs);
-
-    assert(bs != bs_snapshots);
     g_free(bs);
 }
 
@@ -1588,9 +1681,6 @@ void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
 {
     bs->dev_ops = ops;
     bs->dev_opaque = opaque;
-    if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) {
-        bs_snapshots = NULL;
-    }
 }
 
 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
@@ -1792,16 +1882,6 @@ int bdrv_commit_all(void)
     return 0;
 }
 
-struct BdrvTrackedRequest {
-    BlockDriverState *bs;
-    int64_t sector_num;
-    int nb_sectors;
-    bool is_write;
-    QLIST_ENTRY(BdrvTrackedRequest) list;
-    Coroutine *co; /* owner, used for deadlock detection */
-    CoQueue wait_queue; /* coroutines blocked on this request */
-};
-
 /**
  * Remove an active request from the tracked requests list
  *
@@ -2115,6 +2195,7 @@ typedef struct RwCo {
     QEMUIOVector *qiov;
     bool is_write;
     int ret;
+    BdrvRequestFlags flags;
 } RwCo;
 
 static void coroutine_fn bdrv_rw_co_entry(void *opaque)
@@ -2123,10 +2204,12 @@ static void coroutine_fn bdrv_rw_co_entry(void *opaque)
 
     if (!rwco->is_write) {
         rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
-                                     rwco->nb_sectors, rwco->qiov, 0);
+                                     rwco->nb_sectors, rwco->qiov,
+                                     rwco->flags);
     } else {
         rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
-                                      rwco->nb_sectors, rwco->qiov, 0);
+                                      rwco->nb_sectors, rwco->qiov,
+                                      rwco->flags);
     }
 }
 
@@ -2134,7 +2217,8 @@ static void coroutine_fn bdrv_rw_co_entry(void *opaque)
  * Process a vectored synchronous request using coroutines
  */
 static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num,
-                       QEMUIOVector *qiov, bool is_write)
+                       QEMUIOVector *qiov, bool is_write,
+                       BdrvRequestFlags flags)
 {
     Coroutine *co;
     RwCo rwco = {
@@ -2144,6 +2228,7 @@ static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num,
         .qiov = qiov,
         .is_write = is_write,
         .ret = NOT_DONE,
+        .flags = flags,
     };
     assert((qiov->size & (BDRV_SECTOR_SIZE - 1)) == 0);
 
@@ -2175,7 +2260,7 @@ static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num,
  * Process a synchronous request using coroutines
  */
 static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
-                      int nb_sectors, bool is_write)
+                      int nb_sectors, bool is_write, BdrvRequestFlags flags)
 {
     QEMUIOVector qiov;
     struct iovec iov = {
@@ -2184,14 +2269,14 @@ static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
     };
 
     qemu_iovec_init_external(&qiov, &iov, 1);
-    return bdrv_rwv_co(bs, sector_num, &qiov, is_write);
+    return bdrv_rwv_co(bs, sector_num, &qiov, is_write, flags);
 }
 
 /* return < 0 if error. See bdrv_write() for the return codes */
 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
               uint8_t *buf, int nb_sectors)
 {
-    return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
+    return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
 }
 
 /* Just like bdrv_read(), but with I/O throttling temporarily disabled */
@@ -2203,7 +2288,7 @@ int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
 
     enabled = bs->io_limits_enabled;
     bs->io_limits_enabled = false;
-    ret = bdrv_read(bs, 0, buf, 1);
+    ret = bdrv_read(bs, sector_num, buf, nb_sectors);
     bs->io_limits_enabled = enabled;
     return ret;
 }
@@ -2217,12 +2302,18 @@ int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
                const uint8_t *buf, int nb_sectors)
 {
-    return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true);
+    return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
 }
 
 int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov)
 {
-    return bdrv_rwv_co(bs, sector_num, qiov, true);
+    return bdrv_rwv_co(bs, sector_num, qiov, true, 0);
+}
+
+int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
+{
+    return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
+                      BDRV_REQ_ZERO_WRITE);
 }
 
 int bdrv_pread(BlockDriverState *bs, int64_t offset,
@@ -2480,7 +2571,35 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
         }
     }
 
-    ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+    if (!(bs->zero_beyond_eof && bs->growable)) {
+        ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+    } else {
+        /* Read zeros after EOF of growable BDSes */
+        int64_t len, total_sectors, max_nb_sectors;
+
+        len = bdrv_getlength(bs);
+        if (len < 0) {
+            ret = len;
+            goto out;
+        }
+
+        total_sectors = len >> BDRV_SECTOR_BITS;
+        max_nb_sectors = MAX(0, total_sectors - sector_num);
+        if (max_nb_sectors > 0) {
+            ret = drv->bdrv_co_readv(bs, sector_num,
+                                     MIN(nb_sectors, max_nb_sectors), qiov);
+        } else {
+            ret = 0;
+        }
+
+        /* Reading beyond end of file is supposed to produce zeroes */
+        if (ret == 0 && total_sectors < sector_num + nb_sectors) {
+            uint64_t offset = MAX(0, total_sectors - sector_num);
+            uint64_t bytes = (sector_num + nb_sectors - offset) *
+                              BDRV_SECTOR_SIZE;
+            qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
+        }
+    }
 
 out:
     tracked_request_end(&req);
@@ -2572,7 +2691,11 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
 
     tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
 
-    if (flags & BDRV_REQ_ZERO_WRITE) {
+    ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);
+
+    if (ret < 0) {
+        /* Do nothing, write notifier decided to fail this request */
+    } else if (flags & BDRV_REQ_ZERO_WRITE) {
         ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors);
     } else {
         ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
@@ -2859,13 +2982,24 @@ int bdrv_get_flags(BlockDriverState *bs)
     return bs->open_flags;
 }
 
-void bdrv_flush_all(void)
+int bdrv_flush_all(void)
 {
     BlockDriverState *bs;
+    int result = 0;
 
     QTAILQ_FOREACH(bs, &bdrv_states, list) {
-        bdrv_flush(bs);
+        int ret = bdrv_flush(bs);
+        if (ret < 0 && !result) {
+            result = ret;
+        }
     }
+
+    return result;
+}
+
+int bdrv_has_zero_init_1(BlockDriverState *bs)
+{
+    return 1;
 }
 
 int bdrv_has_zero_init(BlockDriverState *bs)
@@ -2876,7 +3010,8 @@ int bdrv_has_zero_init(BlockDriverState *bs)
         return bs->drv->bdrv_has_zero_init(bs);
     }
 
-    return 1;
+    /* safe default */
+    return 0;
 }
 
 typedef struct BdrvCoIsAllocatedData {
@@ -3052,128 +3187,6 @@ int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
     return data.ret;
 }
 
-BlockInfo *bdrv_query_info(BlockDriverState *bs)
-{
-    BlockInfo *info = g_malloc0(sizeof(*info));
-    info->device = g_strdup(bs->device_name);
-    info->type = g_strdup("unknown");
-    info->locked = bdrv_dev_is_medium_locked(bs);
-    info->removable = bdrv_dev_has_removable_media(bs);
-
-    if (bdrv_dev_has_removable_media(bs)) {
-        info->has_tray_open = true;
-        info->tray_open = bdrv_dev_is_tray_open(bs);
-    }
-
-    if (bdrv_iostatus_is_enabled(bs)) {
-        info->has_io_status = true;
-        info->io_status = bs->iostatus;
-    }
-
-    if (bs->dirty_bitmap) {
-        info->has_dirty = true;
-        info->dirty = g_malloc0(sizeof(*info->dirty));
-        info->dirty->count = bdrv_get_dirty_count(bs) * BDRV_SECTOR_SIZE;
-        info->dirty->granularity =
-            ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bs->dirty_bitmap));
-    }
-
-    if (bs->drv) {
-        info->has_inserted = true;
-        info->inserted = g_malloc0(sizeof(*info->inserted));
-        info->inserted->file = g_strdup(bs->filename);
-        info->inserted->ro = bs->read_only;
-        info->inserted->drv = g_strdup(bs->drv->format_name);
-        info->inserted->encrypted = bs->encrypted;
-        info->inserted->encryption_key_missing = bdrv_key_required(bs);
-
-        if (bs->backing_file[0]) {
-            info->inserted->has_backing_file = true;
-            info->inserted->backing_file = g_strdup(bs->backing_file);
-        }
-
-        info->inserted->backing_file_depth = bdrv_get_backing_file_depth(bs);
-
-        if (bs->io_limits_enabled) {
-            info->inserted->bps =
-                           bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
-            info->inserted->bps_rd =
-                           bs->io_limits.bps[BLOCK_IO_LIMIT_READ];
-            info->inserted->bps_wr =
-                           bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE];
-            info->inserted->iops =
-                           bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
-            info->inserted->iops_rd =
-                           bs->io_limits.iops[BLOCK_IO_LIMIT_READ];
-            info->inserted->iops_wr =
-                           bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE];
-        }
-    }
-    return info;
-}
-
-BlockInfoList *qmp_query_block(Error **errp)
-{
-    BlockInfoList *head = NULL, **p_next = &head;
-    BlockDriverState *bs;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, list) {
-        BlockInfoList *info = g_malloc0(sizeof(*info));
-        info->value = bdrv_query_info(bs);
-
-        *p_next = info;
-        p_next = &info->next;
-    }
-
-    return head;
-}
-
-BlockStats *bdrv_query_stats(const BlockDriverState *bs)
-{
-    BlockStats *s;
-
-    s = g_malloc0(sizeof(*s));
-
-    if (bs->device_name[0]) {
-        s->has_device = true;
-        s->device = g_strdup(bs->device_name);
-    }
-
-    s->stats = g_malloc0(sizeof(*s->stats));
-    s->stats->rd_bytes = bs->nr_bytes[BDRV_ACCT_READ];
-    s->stats->wr_bytes = bs->nr_bytes[BDRV_ACCT_WRITE];
-    s->stats->rd_operations = bs->nr_ops[BDRV_ACCT_READ];
-    s->stats->wr_operations = bs->nr_ops[BDRV_ACCT_WRITE];
-    s->stats->wr_highest_offset = bs->wr_highest_sector * BDRV_SECTOR_SIZE;
-    s->stats->flush_operations = bs->nr_ops[BDRV_ACCT_FLUSH];
-    s->stats->wr_total_time_ns = bs->total_time_ns[BDRV_ACCT_WRITE];
-    s->stats->rd_total_time_ns = bs->total_time_ns[BDRV_ACCT_READ];
-    s->stats->flush_total_time_ns = bs->total_time_ns[BDRV_ACCT_FLUSH];
-
-    if (bs->file) {
-        s->has_parent = true;
-        s->parent = bdrv_query_stats(bs->file);
-    }
-
-    return s;
-}
-
-BlockStatsList *qmp_query_blockstats(Error **errp)
-{
-    BlockStatsList *head = NULL, **p_next = &head;
-    BlockDriverState *bs;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, list) {
-        BlockStatsList *info = g_malloc0(sizeof(*info));
-        info->value = bdrv_query_stats(bs);
-
-        *p_next = info;
-        p_next = &info->next;
-    }
-
-    return head;
-}
-
 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
 {
     if (bs->backing_hd && bs->backing_hd->encrypted)
@@ -3260,13 +3273,11 @@ int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 
 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 {
-    BlockDriver *drv = bs->drv;
-
-    if (!drv || !drv->bdrv_debug_event) {
+    if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
         return;
     }
 
-    drv->bdrv_debug_event(bs, event);
+    bs->drv->bdrv_debug_event(bs, event);
 }
 
 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
@@ -3309,129 +3320,11 @@ bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
     return false;
 }
 
-/**************************************************************/
-/* handling of snapshots */
-
-int bdrv_can_snapshot(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
-        return 0;
-    }
-
-    if (!drv->bdrv_snapshot_create) {
-        if (bs->file != NULL) {
-            return bdrv_can_snapshot(bs->file);
-        }
-        return 0;
-    }
-
-    return 1;
-}
-
 int bdrv_is_snapshot(BlockDriverState *bs)
 {
     return !!(bs->open_flags & BDRV_O_SNAPSHOT);
 }
 
-BlockDriverState *bdrv_snapshots(void)
-{
-    BlockDriverState *bs;
-
-    if (bs_snapshots) {
-        return bs_snapshots;
-    }
-
-    bs = NULL;
-    while ((bs = bdrv_next(bs))) {
-        if (bdrv_can_snapshot(bs)) {
-            bs_snapshots = bs;
-            return bs;
-        }
-    }
-    return NULL;
-}
-
-int bdrv_snapshot_create(BlockDriverState *bs,
-                         QEMUSnapshotInfo *sn_info)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv)
-        return -ENOMEDIUM;
-    if (drv->bdrv_snapshot_create)
-        return drv->bdrv_snapshot_create(bs, sn_info);
-    if (bs->file)
-        return bdrv_snapshot_create(bs->file, sn_info);
-    return -ENOTSUP;
-}
-
-int bdrv_snapshot_goto(BlockDriverState *bs,
-                       const char *snapshot_id)
-{
-    BlockDriver *drv = bs->drv;
-    int ret, open_ret;
-
-    if (!drv)
-        return -ENOMEDIUM;
-    if (drv->bdrv_snapshot_goto)
-        return drv->bdrv_snapshot_goto(bs, snapshot_id);
-
-    if (bs->file) {
-        drv->bdrv_close(bs);
-        ret = bdrv_snapshot_goto(bs->file, snapshot_id);
-        open_ret = drv->bdrv_open(bs, NULL, bs->open_flags);
-        if (open_ret < 0) {
-            bdrv_delete(bs->file);
-            bs->drv = NULL;
-            return open_ret;
-        }
-        return ret;
-    }
-
-    return -ENOTSUP;
-}
-
-int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv)
-        return -ENOMEDIUM;
-    if (drv->bdrv_snapshot_delete)
-        return drv->bdrv_snapshot_delete(bs, snapshot_id);
-    if (bs->file)
-        return bdrv_snapshot_delete(bs->file, snapshot_id);
-    return -ENOTSUP;
-}
-
-int bdrv_snapshot_list(BlockDriverState *bs,
-                       QEMUSnapshotInfo **psn_info)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv)
-        return -ENOMEDIUM;
-    if (drv->bdrv_snapshot_list)
-        return drv->bdrv_snapshot_list(bs, psn_info);
-    if (bs->file)
-        return bdrv_snapshot_list(bs->file, psn_info);
-    return -ENOTSUP;
-}
-
-int bdrv_snapshot_load_tmp(BlockDriverState *bs,
-        const char *snapshot_name)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv) {
-        return -ENOMEDIUM;
-    }
-    if (!bs->read_only) {
-        return -EINVAL;
-    }
-    if (drv->bdrv_snapshot_load_tmp) {
-        return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
-    }
-    return -ENOTSUP;
-}
-
 /* backing_file can either be relative, or absolute, or a protocol.  If it is
  * relative, it must be relative to the chain.  So, passing in bs->filename
  * from a BDS as backing_file should not be done, as that may be relative to
@@ -3527,69 +3420,6 @@ BlockDriverState *bdrv_find_base(BlockDriverState *bs)
     return curr_bs;
 }
 
-#define NB_SUFFIXES 4
-
-char *get_human_readable_size(char *buf, int buf_size, int64_t size)
-{
-    static const char suffixes[NB_SUFFIXES] = "KMGT";
-    int64_t base;
-    int i;
-
-    if (size <= 999) {
-        snprintf(buf, buf_size, "%" PRId64, size);
-    } else {
-        base = 1024;
-        for(i = 0; i < NB_SUFFIXES; i++) {
-            if (size < (10 * base)) {
-                snprintf(buf, buf_size, "%0.1f%c",
-                         (double)size / base,
-                         suffixes[i]);
-                break;
-            } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
-                snprintf(buf, buf_size, "%" PRId64 "%c",
-                         ((size + (base >> 1)) / base),
-                         suffixes[i]);
-                break;
-            }
-            base = base * 1024;
-        }
-    }
-    return buf;
-}
-
-char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
-{
-    char buf1[128], date_buf[128], clock_buf[128];
-    struct tm tm;
-    time_t ti;
-    int64_t secs;
-
-    if (!sn) {
-        snprintf(buf, buf_size,
-                 "%-10s%-20s%7s%20s%15s",
-                 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
-    } else {
-        ti = sn->date_sec;
-        localtime_r(&ti, &tm);
-        strftime(date_buf, sizeof(date_buf),
-                 "%Y-%m-%d %H:%M:%S", &tm);
-        secs = sn->vm_clock_nsec / 1000000000;
-        snprintf(clock_buf, sizeof(clock_buf),
-                 "%02d:%02d:%02d.%03d",
-                 (int)(secs / 3600),
-                 (int)((secs / 60) % 60),
-                 (int)(secs % 60),
-                 (int)((sn->vm_clock_nsec / 1000000) % 1000));
-        snprintf(buf, buf_size,
-                 "%-10s%-20s%7s%20s%15s",
-                 sn->id_str, sn->name,
-                 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
-                 date_buf,
-                 clock_buf);
-    }
-    return buf;
-}
-
 /**************************************************************/
 /* async I/Os */
 
@@ -3917,7 +3747,7 @@ static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
     double   elapsed_time;
     int      bps_ret, iops_ret;
 
-    now = qemu_get_clock_ns(vm_clock);
+    now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     if (now > bs->slice_end) {
         bs->slice_start = now;
         bs->slice_end   = now + BLOCK_IO_SLICE_TIME;
@@ -3937,7 +3767,7 @@ static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
             *wait = max_wait;
         }
 
-        now = qemu_get_clock_ns(vm_clock);
+        now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
         if (bs->slice_end < now + max_wait) {
             bs->slice_end = now + max_wait;
         }
@@ -4279,6 +4109,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
     }
 
     /* Write back cached data to the OS even with cache=unsafe */
+    BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
     if (bs->drv->bdrv_co_flush_to_os) {
         ret = bs->drv->bdrv_co_flush_to_os(bs);
         if (ret < 0) {
@@ -4291,6 +4122,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
         goto flush_parent;
     }
 
+    BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
     if (bs->drv->bdrv_co_flush_to_disk) {
         ret = bs->drv->bdrv_co_flush_to_disk(bs);
     } else if (bs->drv->bdrv_aio_flush) {
@@ -4705,7 +4537,7 @@ void bdrv_img_create(const char *filename, const char *fmt,
         return;
     }
 
-    proto_drv = bdrv_find_protocol(filename);
+    proto_drv = bdrv_find_protocol(filename, true);
     if (!proto_drv) {
         error_setg(errp, "Unknown protocol '%s'", filename);
         return;
@@ -4810,8 +4642,12 @@ void bdrv_img_create(const char *filename, const char *fmt,
             error_setg(errp,"Formatting or formatting option not supported for "
                             "file format '%s'", fmt);
         } else if (ret == -EFBIG) {
-            error_setg(errp, "The image size is too large for file format '%s'",
-                       fmt);
+            const char *cluster_size_hint = "";
+            if (get_option_parameter(create_options, BLOCK_OPT_CLUSTER_SIZE)) {
+                cluster_size_hint = " (try using a larger cluster size)";
+            }
+            error_setg(errp, "The image size is too large for file format '%s'%s",
+                       fmt, cluster_size_hint);
         } else {
             error_setg(errp, "%s: error while creating %s: %s", filename, fmt,
                        strerror(-ret));
@@ -4832,3 +4668,9 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs)
     /* Currently BlockDriverState always uses the main loop AioContext */
     return qemu_get_aio_context();
 }
+
+void bdrv_add_before_write_notifier(BlockDriverState *bs,
+                                    NotifierWithReturn *notifier)
+{
+    notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
+}