Merge remote-tracking branch 'remotes/kevin/tags/for-anthony' into staging

Block patches

# gpg: Signature made Sun 09 Feb 2014 08:12:51 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-anthony:
  block: Fix 32 bit truncation in mark_request_serialising()
  blkdebug: Don't leak bs->file on failure
  block: Don't call ROUND_UP with negative values
  block: bdrv_aligned_pwritev: Assert overlap range
  block: Fix memory leaks in bdrv_co_do_pwritev()
  raw: Fix BlockLimits passthrough
  qemu-iotests: add test for qcow2 preallocation with different cluster sizes
  qcow2: check for NULL l2meta
  qcow2: fix offset overflow in qcow2_alloc_clusters_at()
  qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset()
  block/iscsi: always fill bs->bl.opt_transfer_length
  block: Fail gracefully with missing filename
  qemu-iotests: enable support for NFS protocol
  qemu-iotests: enable test 016 and 025 to work with NFS protocol
  qemu-iotests: blacklist test 020 for NFS protocol
  qemu-iotests: change _supported_proto to file for various tests
  block: add native support for NFS
  qemu-iotest: Make 077 raw-only

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

50 files changed, 730 insertions, 84 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index adc5973..026ea4f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -937,6 +937,11 @@ M: Peter Lieven <pl@kamp.de>
 S: Supported
 F: block/iscsi.c
 
+NFS
+M: Peter Lieven <pl@kamp.de>
+S: Maintained
+F: block/nfs.c
+
 SSH
 M: Richard W.M. Jones <rjones@redhat.com>
 S: Supported
diff --git a/block.c b/block.c
index cb21a5f..636aa11 100644
--- a/block.c
+++ b/block.c
@@ -832,6 +832,12 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
         filename = qdict_get_try_str(options, "filename");
     }
 
+    if (drv->bdrv_needs_filename && !filename) {
+        error_setg(errp, "The '%s' block driver requires a file name",
+                   drv->format_name);
+        return -EINVAL;
+    }
+
     trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
 
     node_name = qdict_get_try_str(options, "node-name");
@@ -1031,11 +1037,6 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
             goto fail;
         }
         qdict_del(options, "filename");
-    } else if (drv->bdrv_needs_filename && !filename) {
-        error_setg(errp, "The '%s' block driver requires a file name",
-                   drv->format_name);
-        ret = -EINVAL;
-        goto fail;
     }
 
     if (!drv->bdrv_file_open) {
@@ -2239,11 +2240,11 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
     QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
 }
 
-static void mark_request_serialising(BdrvTrackedRequest *req, size_t align)
+static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
 {
     int64_t overlap_offset = req->offset & ~(align - 1);
-    int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
-                      - overlap_offset;
+    unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
+                               - overlap_offset;
 
     if (!req->serialising) {
         req->bs->serialising_in_flight++;
@@ -2914,8 +2915,8 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
         }
 
         total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE);
-        max_nb_sectors = MAX(0, ROUND_UP(total_sectors - sector_num,
-                                         align >> BDRV_SECTOR_BITS));
+        max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
+                                  align >> BDRV_SECTOR_BITS);
         if (max_nb_sectors > 0) {
             ret = drv->bdrv_co_readv(bs, sector_num,
                                      MIN(nb_sectors, max_nb_sectors), qiov);
@@ -3133,6 +3134,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     waited = wait_serialising_requests(req);
     assert(!waited || !req->serialising);
+    assert(req->overlap_offset <= offset);
+    assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
 
     ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
 
@@ -3278,9 +3281,9 @@ fail:
 
     if (use_local_qiov) {
         qemu_iovec_destroy(&local_qiov);
-        qemu_vfree(head_buf);
-        qemu_vfree(tail_buf);
     }
+    qemu_vfree(head_buf);
+    qemu_vfree(tail_buf);
 
     return ret;
 }
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 4e8c91e..e254a21 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -12,6 +12,7 @@ block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
 ifeq ($(CONFIG_POSIX),y)
 block-obj-y += nbd.o nbd-client.o sheepdog.o
 block-obj-$(CONFIG_LIBISCSI) += iscsi.o
+block-obj-$(CONFIG_LIBNFS) += nfs.o
 block-obj-$(CONFIG_CURL) += curl.o
 block-obj-$(CONFIG_RBD) += rbd.o
 block-obj-$(CONFIG_GLUSTERFS) += gluster.o
diff --git a/block/blkdebug.c b/block/blkdebug.c
index 56c4cd0..8eb0db0 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -396,14 +396,14 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
     if (error_is_set(&local_err)) {
         error_propagate(errp, local_err);
         ret = -EINVAL;
-        goto fail;
+        goto out;
     }
 
     /* Read rules from config file or command line options */
     config = qemu_opt_get(opts, "config");
     ret = read_config(s, config, options, errp);
     if (ret) {
-        goto fail;
+        goto out;
     }
 
     /* Set initial state */
@@ -414,7 +414,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
                           flags, true, false, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
-        goto fail;
+        goto out;
     }
 
     /* Set request alignment */
@@ -424,11 +424,15 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
     } else {
         error_setg(errp, "Invalid alignment");
         ret = -EINVAL;
-        goto fail;
+        goto fail_unref;
     }
 
     ret = 0;
-fail:
+    goto out;
+
+fail_unref:
+    bdrv_unref(bs->file);
+out:
     qemu_opts_del(opts);
     return ret;
 }
diff --git a/block/iscsi.c b/block/iscsi.c
index 6f4af72..8d0f966 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1330,10 +1330,9 @@ static int iscsi_refresh_limits(BlockDriverState *bs)
         }
         bs->bl.write_zeroes_alignment = sector_lun2qemu(iscsilun->bl.opt_unmap_gran,
                                                         iscsilun);
-
-        bs->bl.opt_transfer_length = sector_lun2qemu(iscsilun->bl.opt_xfer_len,
-                                                     iscsilun);
     }
+    bs->bl.opt_transfer_length = sector_lun2qemu(iscsilun->bl.opt_xfer_len,
+                                                 iscsilun);
     return 0;
 }
 
diff --git a/block/nfs.c b/block/nfs.c
new file mode 100644
index 0000000..ef731f0
--- /dev/null
+++ b/block/nfs.c
@@ -0,0 +1,439 @@
+/*
+ * QEMU Block driver for native access to files on NFS shares
+ *
+ * Copyright (c) 2014 Peter Lieven <pl@kamp.de>
+ *
+ * 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 "config-host.h"
+
+#include <poll.h>
+#include "qemu-common.h"
+#include "qemu/config-file.h"
+#include "qemu/error-report.h"
+#include "block/block_int.h"
+#include "trace.h"
+#include "qemu/iov.h"
+#include "qemu/uri.h"
+#include "sysemu/sysemu.h"
+#include <nfsc/libnfs.h>
+
+typedef struct NFSClient {
+    struct nfs_context *context;
+    struct nfsfh *fh;
+    int events;
+    bool has_zero_init;
+} NFSClient;
+
+typedef struct NFSRPC {
+    int ret;
+    int complete;
+    QEMUIOVector *iov;
+    struct stat *st;
+    Coroutine *co;
+    QEMUBH *bh;
+} NFSRPC;
+
+static void nfs_process_read(void *arg);
+static void nfs_process_write(void *arg);
+
+static void nfs_set_events(NFSClient *client)
+{
+    int ev = nfs_which_events(client->context);
+    if (ev != client->events) {
+        qemu_aio_set_fd_handler(nfs_get_fd(client->context),
+                      (ev & POLLIN) ? nfs_process_read : NULL,
+                      (ev & POLLOUT) ? nfs_process_write : NULL,
+                      client);
+
+    }
+    client->events = ev;
+}
+
+static void nfs_process_read(void *arg)
+{
+    NFSClient *client = arg;
+    nfs_service(client->context, POLLIN);
+    nfs_set_events(client);
+}
+
+static void nfs_process_write(void *arg)
+{
+    NFSClient *client = arg;
+    nfs_service(client->context, POLLOUT);
+    nfs_set_events(client);
+}
+
+static void nfs_co_init_task(NFSClient *client, NFSRPC *task)
+{
+    *task = (NFSRPC) {
+        .co         = qemu_coroutine_self(),
+    };
+}
+
+static void nfs_co_generic_bh_cb(void *opaque)
+{
+    NFSRPC *task = opaque;
+    qemu_bh_delete(task->bh);
+    qemu_coroutine_enter(task->co, NULL);
+}
+
+static void
+nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
+                  void *private_data)
+{
+    NFSRPC *task = private_data;
+    task->complete = 1;
+    task->ret = ret;
+    if (task->ret > 0 && task->iov) {
+        if (task->ret <= task->iov->size) {
+            qemu_iovec_from_buf(task->iov, 0, data, task->ret);
+        } else {
+            task->ret = -EIO;
+        }
+    }
+    if (task->ret == 0 && task->st) {
+        memcpy(task->st, data, sizeof(struct stat));
+    }
+    if (task->co) {
+        task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task);
+        qemu_bh_schedule(task->bh);
+    }
+}
+
+static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
+                                     int64_t sector_num, int nb_sectors,
+                                     QEMUIOVector *iov)
+{
+    NFSClient *client = bs->opaque;
+    NFSRPC task;
+
+    nfs_co_init_task(client, &task);
+    task.iov = iov;
+
+    if (nfs_pread_async(client->context, client->fh,
+                        sector_num * BDRV_SECTOR_SIZE,
+                        nb_sectors * BDRV_SECTOR_SIZE,
+                        nfs_co_generic_cb, &task) != 0) {
+        return -ENOMEM;
+    }
+
+    while (!task.complete) {
+        nfs_set_events(client);
+        qemu_coroutine_yield();
+    }
+
+    if (task.ret < 0) {
+        return task.ret;
+    }
+
+    /* zero pad short reads */
+    if (task.ret < iov->size) {
+        qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
+    }
+
+    return 0;
+}
+
+static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
+                                        int64_t sector_num, int nb_sectors,
+                                        QEMUIOVector *iov)
+{
+    NFSClient *client = bs->opaque;
+    NFSRPC task;
+    char *buf = NULL;
+
+    nfs_co_init_task(client, &task);
+
+    buf = g_malloc(nb_sectors * BDRV_SECTOR_SIZE);
+    qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
+
+    if (nfs_pwrite_async(client->context, client->fh,
+                         sector_num * BDRV_SECTOR_SIZE,
+                         nb_sectors * BDRV_SECTOR_SIZE,
+                         buf, nfs_co_generic_cb, &task) != 0) {
+        g_free(buf);
+        return -ENOMEM;
+    }
+
+    while (!task.complete) {
+        nfs_set_events(client);
+        qemu_coroutine_yield();
+    }
+
+    g_free(buf);
+
+    if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
+        return task.ret < 0 ? task.ret : -EIO;
+    }
+
+    return 0;
+}
+
+static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
+{
+    NFSClient *client = bs->opaque;
+    NFSRPC task;
+
+    nfs_co_init_task(client, &task);
+
+    if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
+                        &task) != 0) {
+        return -ENOMEM;
+    }
+
+    while (!task.complete) {
+        nfs_set_events(client);
+        qemu_coroutine_yield();
+    }
+
+    return task.ret;
+}
+
+/* TODO Convert to fine grained options */
+static QemuOptsList runtime_opts = {
+    .name = "nfs",
+    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
+    .desc = {
+        {
+            .name = "filename",
+            .type = QEMU_OPT_STRING,
+            .help = "URL to the NFS file",
+        },
+        { /* end of list */ }
+    },
+};
+
+static void nfs_client_close(NFSClient *client)
+{
+    if (client->context) {
+        if (client->fh) {
+            nfs_close(client->context, client->fh);
+        }
+        qemu_aio_set_fd_handler(nfs_get_fd(client->context), NULL, NULL, NULL);
+        nfs_destroy_context(client->context);
+    }
+    memset(client, 0, sizeof(NFSClient));
+}
+
+static void nfs_file_close(BlockDriverState *bs)
+{
+    NFSClient *client = bs->opaque;
+    nfs_client_close(client);
+}
+
+static int64_t nfs_client_open(NFSClient *client, const char *filename,
+                               int flags, Error **errp)
+{
+    int ret = -EINVAL, i;
+    struct stat st;
+    URI *uri;
+    QueryParams *qp = NULL;
+    char *file = NULL, *strp = NULL;
+
+    uri = uri_parse(filename);
+    if (!uri) {
+        error_setg(errp, "Invalid URL specified");
+        goto fail;
+    }
+    strp = strrchr(uri->path, '/');
+    if (strp == NULL) {
+        error_setg(errp, "Invalid URL specified");
+        goto fail;
+    }
+    file = g_strdup(strp);
+    *strp = 0;
+
+    client->context = nfs_init_context();
+    if (client->context == NULL) {
+        error_setg(errp, "Failed to init NFS context");
+        goto fail;
+    }
+
+    qp = query_params_parse(uri->query);
+    for (i = 0; i < qp->n; i++) {
+        if (!qp->p[i].value) {
+            error_setg(errp, "Value for NFS parameter expected: %s",
+                       qp->p[i].name);
+            goto fail;
+        }
+        if (!strncmp(qp->p[i].name, "uid", 3)) {
+            nfs_set_uid(client->context, atoi(qp->p[i].value));
+        } else if (!strncmp(qp->p[i].name, "gid", 3)) {
+            nfs_set_gid(client->context, atoi(qp->p[i].value));
+        } else if (!strncmp(qp->p[i].name, "tcp-syncnt", 10)) {
+            nfs_set_tcp_syncnt(client->context, atoi(qp->p[i].value));
+        } else {
+            error_setg(errp, "Unknown NFS parameter name: %s",
+                       qp->p[i].name);
+            goto fail;
+        }
+    }
+
+    ret = nfs_mount(client->context, uri->server, uri->path);
+    if (ret < 0) {
+        error_setg(errp, "Failed to mount nfs share: %s",
+                   nfs_get_error(client->context));
+        goto fail;
+    }
+
+    if (flags & O_CREAT) {
+        ret = nfs_creat(client->context, file, 0600, &client->fh);
+        if (ret < 0) {
+            error_setg(errp, "Failed to create file: %s",
+                       nfs_get_error(client->context));
+            goto fail;
+        }
+    } else {
+        ret = nfs_open(client->context, file, flags, &client->fh);
+        if (ret < 0) {
+            error_setg(errp, "Failed to open file : %s",
+                       nfs_get_error(client->context));
+            goto fail;
+        }
+    }
+
+    ret = nfs_fstat(client->context, client->fh, &st);
+    if (ret < 0) {
+        error_setg(errp, "Failed to fstat file: %s",
+                   nfs_get_error(client->context));
+        goto fail;
+    }
+
+    ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
+    client->has_zero_init = S_ISREG(st.st_mode);
+    goto out;
+fail:
+    nfs_client_close(client);
+out:
+    if (qp) {
+        query_params_free(qp);
+    }
+    uri_free(uri);
+    g_free(file);
+    return ret;
+}
+
+static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
+                         Error **errp) {
+    NFSClient *client = bs->opaque;
+    int64_t ret;
+    QemuOpts *opts;
+    Error *local_err = NULL;
+
+    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (error_is_set(&local_err)) {
+        error_propagate(errp, local_err);
+        return -EINVAL;
+    }
+    ret = nfs_client_open(client, qemu_opt_get(opts, "filename"),
+                          (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
+                          errp);
+    if (ret < 0) {
+        return ret;
+    }
+    bs->total_sectors = ret;
+    return 0;
+}
+
+static int nfs_file_create(const char *url, QEMUOptionParameter *options,
+                           Error **errp)
+{
+    int ret = 0;
+    int64_t total_size = 0;
+    NFSClient *client = g_malloc0(sizeof(NFSClient));
+
+    /* Read out options */
+    while (options && options->name) {
+        if (!strcmp(options->name, "size")) {
+            total_size = options->value.n;
+        }
+        options++;
+    }
+
+    ret = nfs_client_open(client, url, O_CREAT, errp);
+    if (ret < 0) {
+        goto out;
+    }
+    ret = nfs_ftruncate(client->context, client->fh, total_size);
+    nfs_client_close(client);
+out:
+    g_free(client);
+    return ret;
+}
+
+static int nfs_has_zero_init(BlockDriverState *bs)
+{
+    NFSClient *client = bs->opaque;
+    return client->has_zero_init;
+}
+
+static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
+{
+    NFSClient *client = bs->opaque;
+    NFSRPC task = {0};
+    struct stat st;
+
+    task.st = &st;
+    if (nfs_fstat_async(client->context, client->fh, nfs_co_generic_cb,
+                        &task) != 0) {
+        return -ENOMEM;
+    }
+
+    while (!task.complete) {
+        nfs_set_events(client);
+        qemu_aio_wait();
+    }
+
+    return (task.ret < 0 ? task.ret : st.st_blocks * st.st_blksize);
+}
+
+static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
+{
+    NFSClient *client = bs->opaque;
+    return nfs_ftruncate(client->context, client->fh, offset);
+}
+
+static BlockDriver bdrv_nfs = {
+    .format_name     = "nfs",
+    .protocol_name   = "nfs",
+
+    .instance_size   = sizeof(NFSClient),
+    .bdrv_needs_filename = true,
+    .bdrv_has_zero_init = nfs_has_zero_init,
+    .bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
+    .bdrv_truncate = nfs_file_truncate,
+
+    .bdrv_file_open  = nfs_file_open,
+    .bdrv_close      = nfs_file_close,
+    .bdrv_create     = nfs_file_create,
+
+    .bdrv_co_readv         = nfs_co_readv,
+    .bdrv_co_writev        = nfs_co_writev,
+    .bdrv_co_flush_to_disk = nfs_co_flush,
+};
+
+static void nfs_block_init(void)
+{
+    bdrv_register(&bdrv_nfs);
+}
+
+block_init(nfs_block_init);
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 8534084..c57f39d 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1182,7 +1182,7 @@ fail:
  * Return 0 on success and -errno in error cases
  */
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m)
+    int *num, uint64_t *host_offset, QCowL2Meta **m)
 {
     BDRVQcowState *s = bs->opaque;
     uint64_t start, remaining;
@@ -1190,15 +1190,13 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
     uint64_t cur_bytes;
     int ret;
 
-    trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset,
-                                      n_start, n_end);
+    trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *num);
 
-    assert(n_start * BDRV_SECTOR_SIZE == offset_into_cluster(s, offset));
-    offset = start_of_cluster(s, offset);
+    assert((offset & ~BDRV_SECTOR_MASK) == 0);
 
 again:
-    start = offset + (n_start << BDRV_SECTOR_BITS);
-    remaining = (n_end - n_start) << BDRV_SECTOR_BITS;
+    start = offset;
+    remaining = *num << BDRV_SECTOR_BITS;
     cluster_offset = 0;
     *host_offset = 0;
     cur_bytes = 0;
@@ -1284,7 +1282,7 @@ again:
         }
     }
 
-    *num = (n_end - n_start) - (remaining >> BDRV_SECTOR_BITS);
+    *num -= remaining >> BDRV_SECTOR_BITS;
     assert(*num > 0);
     assert(*host_offset != 0);
 
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index c974abe..8712d8b 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -676,7 +676,13 @@ int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
     BDRVQcowState *s = bs->opaque;
     uint64_t cluster_index;
     uint64_t old_free_cluster_index;
-    int i, refcount, ret;
+    uint64_t i;
+    int refcount, ret;
+
+    assert(nb_clusters >= 0);
+    if (nb_clusters == 0) {
+        return 0;
+    }
 
     /* Check how many clusters there are free */
     cluster_index = offset >> s->cluster_bits;
diff --git a/block/qcow2.c b/block/qcow2.c
index 99a1ad1..0b4335c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1000,7 +1000,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
 {
     BDRVQcowState *s = bs->opaque;
     int index_in_cluster;
-    int n_end;
     int ret;
     int cur_nr_sectors; /* number of sectors in current iteration */
     uint64_t cluster_offset;
@@ -1024,14 +1023,16 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
 
         trace_qcow2_writev_start_part(qemu_coroutine_self());
         index_in_cluster = sector_num & (s->cluster_sectors - 1);
-        n_end = index_in_cluster + remaining_sectors;
+        cur_nr_sectors = remaining_sectors;
         if (s->crypt_method &&
-            n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) {
-            n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
+            cur_nr_sectors >
+            QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) {
+            cur_nr_sectors =
+                QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster;
         }
 
         ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
-            index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta);
+            &cur_nr_sectors, &cluster_offset, &l2meta);
         if (ret < 0) {
             goto fail;
         }
@@ -1403,34 +1404,34 @@ static int preallocate(BlockDriverState *bs)
     int ret;
     QCowL2Meta *meta;
 
-    nb_sectors = bdrv_getlength(bs) >> 9;
+    nb_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
     offset = 0;
 
     while (nb_sectors) {
-        num = MIN(nb_sectors, INT_MAX >> 9);
-        ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
+        num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS);
+        ret = qcow2_alloc_cluster_offset(bs, offset, &num,
                                          &host_offset, &meta);
         if (ret < 0) {
             return ret;
         }
 
-        ret = qcow2_alloc_cluster_link_l2(bs, meta);
-        if (ret < 0) {
-            qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters,
-                                    QCOW2_DISCARD_NEVER);
-            return ret;
-        }
-
-        /* There are no dependent requests, but we need to remove our request
-         * from the list of in-flight requests */
         if (meta != NULL) {
+            ret = qcow2_alloc_cluster_link_l2(bs, meta);
+            if (ret < 0) {
+                qcow2_free_any_clusters(bs, meta->alloc_offset,
+                                        meta->nb_clusters, QCOW2_DISCARD_NEVER);
+                return ret;
+            }
+
+            /* There are no dependent requests, but we need to remove our
+             * request from the list of in-flight requests */
             QLIST_REMOVE(meta, next_in_flight);
         }
 
         /* TODO Preallocate data if requested */
 
         nb_sectors -= num;
-        offset += num << 9;
+        offset += num << BDRV_SECTOR_BITS;
     }
 
     /*
@@ -1439,9 +1440,10 @@ static int preallocate(BlockDriverState *bs)
      * EOF). Extend the image to the last allocated sector.
      */
     if (host_offset != 0) {
-        uint8_t buf[512];
-        memset(buf, 0, 512);
-        ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1);
+        uint8_t buf[BDRV_SECTOR_SIZE];
+        memset(buf, 0, BDRV_SECTOR_SIZE);
+        ret = bdrv_write(bs->file, (host_offset >> BDRV_SECTOR_BITS) + num - 1,
+                         buf, 1);
         if (ret < 0) {
             return ret;
         }
diff --git a/block/qcow2.h b/block/qcow2.h
index b5b7d13..0b0eac8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -468,7 +468,7 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     int *num, uint64_t *cluster_offset);
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m);
+    int *num, uint64_t *host_offset, QCowL2Meta **m);
 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
                                          uint64_t offset,
                                          int compressed_size);
diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index 978ae7a..af8706d 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -90,6 +90,12 @@ static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return bdrv_get_info(bs->file, bdi);
 }
 
+static int raw_refresh_limits(BlockDriverState *bs)
+{
+    bs->bl = bs->file->bl;
+    return 0;
+}
+
 static int raw_truncate(BlockDriverState *bs, int64_t offset)
 {
     return bdrv_truncate(bs->file, offset);
@@ -150,7 +156,6 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
                     Error **errp)
 {
     bs->sg = bs->file->sg;
-    bs->bl = bs->file->bl;
     return 0;
 }
 
@@ -182,6 +187,7 @@ static BlockDriver bdrv_raw = {
     .bdrv_getlength       = &raw_getlength,
     .has_variable_length  = true,
     .bdrv_get_info        = &raw_get_info,
+    .bdrv_refresh_limits  = &raw_refresh_limits,
     .bdrv_is_inserted     = &raw_is_inserted,
     .bdrv_media_changed   = &raw_media_changed,
     .bdrv_eject           = &raw_eject,
diff --git a/configure b/configure
index 8f3cc20..88133a1 100755
--- a/configure
+++ b/configure
@@ -251,6 +251,7 @@ vss_win32_sdk=""
 win_sdk="no"
 want_tools="yes"
 libiscsi=""
+libnfs=""
 coroutine=""
 coroutine_pool=""
 seccomp=""
@@ -840,6 +841,10 @@ for opt do
   ;;
   --enable-libiscsi) libiscsi="yes"
   ;;
+  --disable-libnfs) libnfs="no"
+  ;;
+  --enable-libnfs) libnfs="yes"
+  ;;
   --enable-profiler) profiler="yes"
   ;;
   --disable-cocoa) cocoa="no"
@@ -1229,6 +1234,8 @@ Advanced options (experts only):
   --enable-rbd             enable building the rados block device (rbd)
   --disable-libiscsi       disable iscsi support
   --enable-libiscsi        enable iscsi support
+  --disable-libnfs         disable nfs support
+  --enable-libnfs          enable nfs support
   --disable-smartcard-nss  disable smartcard nss support
   --enable-smartcard-nss   enable smartcard nss support
   --disable-libusb         disable libusb (for usb passthrough)
@@ -3600,6 +3607,20 @@ elif test "$debug" = "no" ; then
   CFLAGS="-O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $CFLAGS"
 fi
 
+##########################################
+# Do we have libnfs
+if test "$libnfs" != "no" ; then
+  if $pkg_config --atleast-version=1.9.2 libnfs; then
+    libnfs="yes"
+    libnfs_libs=$($pkg_config --libs libnfs)
+    LIBS="$LIBS $libnfs_libs"
+  else
+    if test "$libnfs" = "yes" ; then
+      feature_not_found "libnfs"
+    fi
+    libnfs="no"
+  fi
+fi
 
 # Disable zero malloc errors for official releases unless explicitly told to
 # enable/disable
@@ -3829,6 +3850,7 @@ echo "libiscsi support  $libiscsi (1.4.0)"
 else
 echo "libiscsi support  $libiscsi"
 fi
+echo "libnfs support    $libnfs"
 echo "build guest agent $guest_agent"
 echo "QGA VSS support   $guest_agent_with_vss"
 echo "seccomp support   $seccomp"
@@ -4165,6 +4187,10 @@ if test "$libiscsi" = "yes" ; then
   fi
 fi
 
+if test "$libnfs" = "yes" ; then
+  echo "CONFIG_LIBNFS=y" >> $config_host_mak
+fi
+
 if test "$seccomp" = "yes"; then
   echo "CONFIG_SECCOMP=y" >> $config_host_mak
 fi
diff --git a/qapi-schema.json b/qapi-schema.json
index 05ced9d..7cfb5e5 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4371,6 +4371,7 @@
 # TODO gluster: Wait for structured options
 # TODO iscsi: Wait for structured options
 # TODO nbd: Should take InetSocketAddress for 'host'?
+# TODO nfs: Wait for structured options
 # TODO rbd: Wait for structured options
 # TODO sheepdog: Wait for structured options
 # TODO ssh: Should take InetSocketAddress for 'host'?
diff --git a/tests/qemu-iotests/013 b/tests/qemu-iotests/013
index 389f4b8..ea3cab9 100755
--- a/tests/qemu-iotests/013
+++ b/tests/qemu-iotests/013
@@ -41,7 +41,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # much of this could be generic for any format supporting compression.
 _supported_fmt qcow qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 TEST_OFFSETS="0 4294967296"
diff --git a/tests/qemu-iotests/014 b/tests/qemu-iotests/014
index 0edeb4b..b23c2db 100755
--- a/tests/qemu-iotests/014
+++ b/tests/qemu-iotests/014
@@ -43,7 +43,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # much of this could be generic for any format supporting snapshots
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 TEST_OFFSETS="0 4294967296"
diff --git a/tests/qemu-iotests/016 b/tests/qemu-iotests/016
index b87a32b..7ea9e94 100755
--- a/tests/qemu-iotests/016
+++ b/tests/qemu-iotests/016
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt raw
-_supported_proto file sheepdog
+_supported_proto file sheepdog nfs
 _supported_os Linux
 
 
diff --git a/tests/qemu-iotests/018 b/tests/qemu-iotests/018
index 6f7f054..d8a7d43 100755
--- a/tests/qemu-iotests/018
+++ b/tests/qemu-iotests/018
@@ -41,7 +41,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # Any format supporting backing files
 _supported_fmt qcow qcow2 vmdk qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" "subformat=twoGbMaxExtentFlat"
 
diff --git a/tests/qemu-iotests/019 b/tests/qemu-iotests/019
index b43e70f..e67445c 100755
--- a/tests/qemu-iotests/019
+++ b/tests/qemu-iotests/019
@@ -45,7 +45,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # Any format supporting backing files
 _supported_fmt qcow qcow2 vmdk qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
diff --git a/tests/qemu-iotests/020 b/tests/qemu-iotests/020
index 73a0429..2f258dc 100755
--- a/tests/qemu-iotests/020
+++ b/tests/qemu-iotests/020
@@ -49,6 +49,11 @@ _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
                      "subformat=twoGbMaxExtentSparse"
 
+# NFS does not support bdrv_reopen_prepare thus qemu-img commit fails.
+if [ "$IMGPROTO" = "nfs" ]; then
+    _notrun "image protocol $IMGPROTO does not support bdrv_commit"
+fi
+
 TEST_OFFSETS="0 4294967296"
 
 _make_test_img 6G
diff --git a/tests/qemu-iotests/023 b/tests/qemu-iotests/023
index 090ed23..9ad06b9 100755
--- a/tests/qemu-iotests/023
+++ b/tests/qemu-iotests/023
@@ -41,7 +41,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # much of this could be generic for any format supporting compression.
 _supported_fmt qcow qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 TEST_OFFSETS="0 4294967296"
diff --git a/tests/qemu-iotests/024 b/tests/qemu-iotests/024
index be974f0..9bf99e1 100755
--- a/tests/qemu-iotests/024
+++ b/tests/qemu-iotests/024
@@ -43,7 +43,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # Currently only qcow2 and qed support rebasing
 _supported_fmt qcow2 qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 CLUSTER_SIZE=65536
diff --git a/tests/qemu-iotests/025 b/tests/qemu-iotests/025
index 9426c93..a5f45b4 100755
--- a/tests/qemu-iotests/025
+++ b/tests/qemu-iotests/025
@@ -40,7 +40,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.pattern
 
 _supported_fmt raw qcow2 qed
-_supported_proto file sheepdog rbd
+_supported_proto file sheepdog rbd nfs
 _supported_os Linux
 
 echo "=== Creating image"
diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index c9c5f83..df2884b 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # Currently only qcow2 supports rebasing
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _default_cache_mode "writethrough"
 _supported_cache_modes "writethrough" "none"
diff --git a/tests/qemu-iotests/028 b/tests/qemu-iotests/028
index 93a9fa6..a99e4fa 100755
--- a/tests/qemu-iotests/028
+++ b/tests/qemu-iotests/028
@@ -45,7 +45,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 # Any format supporting backing files except vmdk and qcow which do not support
 # smaller backing files.
 _supported_fmt qcow2 qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 # Choose a size that is not necessarily a cluster size multiple for image
diff --git a/tests/qemu-iotests/031 b/tests/qemu-iotests/031
index c9070b0..1d920ea 100755
--- a/tests/qemu-iotests/031
+++ b/tests/qemu-iotests/031
@@ -41,7 +41,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 CLUSTER_SIZE=65536
diff --git a/tests/qemu-iotests/034 b/tests/qemu-iotests/034
index 7349789..69c7858 100755
--- a/tests/qemu-iotests/034
+++ b/tests/qemu-iotests/034
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow qcow2 vmdk qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
diff --git a/tests/qemu-iotests/036 b/tests/qemu-iotests/036
index e049a64..03b6aa9 100755
--- a/tests/qemu-iotests/036
+++ b/tests/qemu-iotests/036
@@ -44,7 +44,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 # Only qcow2v3 and later supports feature bits
diff --git a/tests/qemu-iotests/037 b/tests/qemu-iotests/037
index e444349..9171d8c 100755
--- a/tests/qemu-iotests/037
+++ b/tests/qemu-iotests/037
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow qcow2 vmdk qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
diff --git a/tests/qemu-iotests/038 b/tests/qemu-iotests/038
index 7bb7906..cfaf00a 100755
--- a/tests/qemu-iotests/038
+++ b/tests/qemu-iotests/038
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow2 qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 CLUSTER_SIZE=2M
diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039
index 6abf472..9b355c0 100755
--- a/tests/qemu-iotests/039
+++ b/tests/qemu-iotests/039
@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _default_cache_mode "writethrough"
 _supported_cache_modes "writethrough"
diff --git a/tests/qemu-iotests/043 b/tests/qemu-iotests/043
index d7f1231..b316b97 100755
--- a/tests/qemu-iotests/043
+++ b/tests/qemu-iotests/043
@@ -41,7 +41,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # Any format supporting backing files
 _supported_fmt qcow2 qed
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 
diff --git a/tests/qemu-iotests/046 b/tests/qemu-iotests/046
index 3f17ceb..2d44bbb 100755
--- a/tests/qemu-iotests/046
+++ b/tests/qemu-iotests/046
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 CLUSTER_SIZE=64k
diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index b23d91b..46345fb 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -172,6 +172,18 @@ run_qemu -drive file="$TEST_IMG",file.driver=file
 run_qemu -drive file="$TEST_IMG",file.driver=qcow2
 
 echo
+echo === Leaving out required options ===
+echo
+
+run_qemu -drive driver=file
+run_qemu -drive driver=nbd
+run_qemu -drive driver=raw
+run_qemu -drive file.driver=file
+run_qemu -drive file.driver=nbd
+run_qemu -drive file.driver=raw
+run_qemu -drive foo=bar
+
+echo
 echo === Parsing protocol from file name ===
 echo
 
diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out
index d0c5173..30e2dbd 100644
--- a/tests/qemu-iotests/051.out
+++ b/tests/qemu-iotests/051.out
@@ -225,6 +225,30 @@ Testing: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2
 QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: could not open disk image TEST_DIR/t.qcow2: Block format 'qcow2' used by device '' doesn't support the option 'filename'
 
 
+=== Leaving out required options ===
+
+Testing: -drive driver=file
+QEMU_PROG: -drive driver=file: could not open disk image ide0-hd0: The 'file' block driver requires a file name
+
+Testing: -drive driver=nbd
+QEMU_PROG: -drive driver=nbd: could not open disk image ide0-hd0: Could not open image: Invalid argument
+
+Testing: -drive driver=raw
+QEMU_PROG: -drive driver=raw: could not open disk image ide0-hd0: Can't use 'raw' as a block driver for the protocol level
+
+Testing: -drive file.driver=file
+QEMU_PROG: -drive file.driver=file: could not open disk image ide0-hd0: The 'file' block driver requires a file name
+
+Testing: -drive file.driver=nbd
+QEMU_PROG: -drive file.driver=nbd: could not open disk image ide0-hd0: Could not open image: Invalid argument
+
+Testing: -drive file.driver=raw
+QEMU_PROG: -drive file.driver=raw: could not open disk image ide0-hd0: Can't use 'raw' as a block driver for the protocol level
+
+Testing: -drive foo=bar
+QEMU_PROG: -drive foo=bar: could not open disk image ide0-hd0: Must specify either driver or file
+
+
 === Parsing protocol from file name ===
 
 Testing: -hda foo:bar
diff --git a/tests/qemu-iotests/052 b/tests/qemu-iotests/052
index 4d4e411..6bdae92 100755
--- a/tests/qemu-iotests/052
+++ b/tests/qemu-iotests/052
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt generic
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _default_cache_mode "writethrough"
 _supported_cache_modes "writethrough"
diff --git a/tests/qemu-iotests/054 b/tests/qemu-iotests/054
index 5a0d1b1..c8b7082 100755
--- a/tests/qemu-iotests/054
+++ b/tests/qemu-iotests/054
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 echo
diff --git a/tests/qemu-iotests/059 b/tests/qemu-iotests/059
index 2d604d3..ca5aa16 100755
--- a/tests/qemu-iotests/059
+++ b/tests/qemu-iotests/059
@@ -40,7 +40,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # This tests vmdk-specific low-level functionality
 _supported_fmt vmdk
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
diff --git a/tests/qemu-iotests/060 b/tests/qemu-iotests/060
index bbb1909..af8ed9f 100755
--- a/tests/qemu-iotests/060
+++ b/tests/qemu-iotests/060
@@ -40,7 +40,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # This tests qocw2-specific low-level functionality
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 rt_offset=65536  # 0x10000 (XXX: just an assumption)
diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
index e42f9bd..d3a6b38 100755
--- a/tests/qemu-iotests/061
+++ b/tests/qemu-iotests/061
@@ -40,7 +40,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # This tests qocw2-specific low-level functionality
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 echo
diff --git a/tests/qemu-iotests/063 b/tests/qemu-iotests/063
index 77503a2..a47493a 100755
--- a/tests/qemu-iotests/063
+++ b/tests/qemu-iotests/063
@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.pattern
 
 _supported_fmt qcow qcow2 vmdk qed raw
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" \
                      "subformat=twoGbMaxExtentFlat" \
diff --git a/tests/qemu-iotests/069 b/tests/qemu-iotests/069
index 50347d9..e661598 100755
--- a/tests/qemu-iotests/069
+++ b/tests/qemu-iotests/069
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt cow qed qcow qcow2 vmdk
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 _unsupported_imgopts "subformat=monolithicFlat" "subformat=twoGbMaxExtentFlat"
 
diff --git a/tests/qemu-iotests/071 b/tests/qemu-iotests/071
index dbc07c6..3924e51 100755
--- a/tests/qemu-iotests/071
+++ b/tests/qemu-iotests/071
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt qcow2
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 function do_run_qemu()
diff --git a/tests/qemu-iotests/072 b/tests/qemu-iotests/072
index a3876c2..58faa8b 100755
--- a/tests/qemu-iotests/072
+++ b/tests/qemu-iotests/072
@@ -39,7 +39,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.filter
 
 _supported_fmt vpc vmdk vhdx vdi qed qcow2 qcow cow
-_supported_proto generic
+_supported_proto file
 _supported_os Linux
 
 IMG_SIZE=64M
diff --git a/tests/qemu-iotests/077 b/tests/qemu-iotests/077
index bbf7b51..4dd1bdd 100755
--- a/tests/qemu-iotests/077
+++ b/tests/qemu-iotests/077
@@ -38,7 +38,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.rc
 . ./common.filter
 
-_supported_fmt generic
+_supported_fmt raw
 _supported_proto generic
 _supported_os Linux
 
diff --git a/tests/qemu-iotests/079 b/tests/qemu-iotests/079
new file mode 100755
index 0000000..2142bbb
--- /dev/null
+++ b/tests/qemu-iotests/079
@@ -0,0 +1,63 @@
+#!/bin/bash
+#
+# Test qcow2 preallocation with different cluster_sizes
+#
+# Copyright (C) 2014 Fujitsu.
+#
+# 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/>.
+#
+
+# creator
+owner=hutao@cn.fujitsu.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+function test_qemu_img()
+{
+    echo qemu-img "$@" | _filter_testdir
+    $QEMU_IMG "$@" 2>&1 | _filter_testdir
+    echo
+}
+
+echo "=== Check option preallocation and cluster_size ==="
+echo
+cluster_sizes="16384 32768 65536 131072 262144 524288 1048576 2097152 4194304"
+
+for s in $cluster_sizes; do
+    test_qemu_img create -f $IMGFMT -o preallocation=metadata,cluster_size=$s "$TEST_IMG" 4G
+done
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/079.out b/tests/qemu-iotests/079.out
new file mode 100644
index 0000000..ef4b8c9
--- /dev/null
+++ b/tests/qemu-iotests/079.out
@@ -0,0 +1,32 @@
+QA output created by 079
+=== Check option preallocation and cluster_size ===
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=16384 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=16384 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=32768 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=32768 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=65536 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=65536 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=131072 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=131072 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=262144 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=262144 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=524288 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=524288 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=1048576 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=1048576 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=2097152 TEST_DIR/t.qcow2 4G
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=2097152 preallocation='metadata' lazy_refcounts=off
+
+qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=4194304 TEST_DIR/t.qcow2 4G
+qemu-img: TEST_DIR/t.qcow2: Cluster size must be a power of two between 512 and 2048k
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=4194304 preallocation='metadata' lazy_refcounts=off
+
+*** done
diff --git a/tests/qemu-iotests/common b/tests/qemu-iotests/common
index 8b4e22c..5795358 100644
--- a/tests/qemu-iotests/common
+++ b/tests/qemu-iotests/common
@@ -144,10 +144,12 @@ check options
     -vpc                test vpc
     -vhdx               test vhdx
     -vmdk               test vmdk
+    -file               test file (default)
     -rbd                test rbd
     -sheepdog           test sheepdog
     -nbd                test nbd
     -ssh                test ssh
+    -nfs                test nfs
     -xdiff              graphical mode diff
     -nocache            use O_DIRECT on backing file
     -misalign           misalign memory allocations
@@ -211,22 +213,36 @@ testlist options
             xpand=false
             ;;
 
+        -file)
+            IMGPROTO=file
+            xpand=false
+            ;;
+
         -rbd)
             IMGPROTO=rbd
             xpand=false
             ;;
+
         -sheepdog)
             IMGPROTO=sheepdog
             xpand=false
             ;;
+
         -nbd)
             IMGPROTO=nbd
             xpand=false
             ;;
+
         -ssh)
             IMGPROTO=ssh
             xpand=false
             ;;
+
+        -nfs)
+            IMGPROTO=nfs
+            xpand=false
+            ;;
+
         -nocache)
             CACHEMODE="none"
             CACHEMODE_IS_DEFAULT=false
@@ -238,10 +254,10 @@ testlist options
             xpand=false
             ;;
 
-    -valgrind)
-        valgrind=true
+        -valgrind)
+            valgrind=true
             xpand=false
-        ;;
+            ;;
 
         -g)        # -g group ... pick from group file
             group=true
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 0f68156..71e9a74 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -61,6 +61,9 @@ elif [ "$IMGPROTO" = "nbd" ]; then
 elif [ "$IMGPROTO" = "ssh" ]; then
     TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
     TEST_IMG="ssh://127.0.0.1$TEST_IMG_FILE"
+elif [ "$IMGPROTO" = "nfs" ]; then
+    TEST_DIR="nfs://127.0.0.1/$TEST_DIR"
+    TEST_IMG=$TEST_DIR/t.$IMGFMT
 else
     TEST_IMG=$IMGPROTO:$TEST_DIR/t.$IMGFMT
 fi
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 03c762f..d8be74a 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -82,3 +82,4 @@
 073 rw auto
 074 rw auto
 077 rw auto
+079 rw auto
diff --git a/trace-events b/trace-events
index 1b668d1..ab11f97 100644
--- a/trace-events
+++ b/trace-events
@@ -495,7 +495,7 @@ qcow2_writev_done_part(void *co, int cur_nr_sectors) "co %p cur_nr_sectors %d"
 qcow2_writev_data(void *co, uint64_t offset) "co %p offset %" PRIx64
 
 # block/qcow2-cluster.c
-qcow2_alloc_clusters_offset(void *co, uint64_t offset, int n_start, int n_end) "co %p offet %" PRIx64 " n_start %d n_end %d"
+qcow2_alloc_clusters_offset(void *co, uint64_t offset, int num) "co %p offet %" PRIx64 " num %d"
 qcow2_handle_copied(void *co, uint64_t guest_offset, uint64_t host_offset, uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %" PRIx64
 qcow2_handle_alloc(void *co, uint64_t guest_offset, uint64_t host_offset, uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %" PRIx64
 qcow2_do_alloc_clusters_offset(void *co, uint64_t guest_offset, uint64_t host_offset, int nb_clusters) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " nb_clusters %d"