This patch adds native support for accessing images on NFS shares without
the requirement to actually mount the entire NFS share on the host.
NFS Images can simply be specified by an url of the form:
nfs://<host>/<export>/<filename>
For example:
qemu-img create -f qcow2 nfs://10.0.0.1/qemu-images/test.qcow2
You need libnfs from Ronnie Sahlberg available at:
git://github.com/sahlberg/libnfs.git
for this to work.
During configure it is automatically probed for libnfs and support
is enabled on-the-fly. You can forbid or enforce libnfs support
with --disable-libnfs or --enable-libnfs respectively.
Due to NFS restrictions you might need to execute your binaries
as root, allow them to open priviledged ports (<1024) or specify
insecure option on the NFS server.
LibNFS currently support NFS version 3 only.
Signed-off-by: Peter Lieven <p...@kamp.de>
---
v2->v3:
- rebased the stefanha/block
- use pkg_config to check for libnfs (ignoring cflags which are broken in
1.8.0) [Stefan]
- fixed NFSClient declaration [Stefan]
- renamed Task variables to task [Stefan]
- renamed NFSTask to NFSRPC [Ronnie]
- do not update bs->total_sectors in nfs_co_writev [Stefan]
- return -ENOMEM on all async call failures [Stefan,Ronnie]
- fully implement ftruncate
- use util/uri.c for URL parsing [Stefan]
- reworked nfs_file_open_common to nfs_client_open which works on NFSClient
[Stefan]
- added a comment ot the connect message that libnfs support NFSv3 only at the
moment.
- DID NOT add full implementation of bdrv_get_allocated_file_size because
we are not in a coroutine context and I cannot do an async call here.
I could do a sync call if there would be a guarantee that no requests
are in flight. [Stefan]
v1->v2:
- fixed block/Makefile.objs [Ronnie]
- do not always register a read handler [Ronnie]
- add support for reading beyond EOF [Fam]
- fixed struct and paramter naming [Fam]
- fixed overlong lines and whitespace errors [Fam]
- return return status from libnfs whereever possible [Fam]
- added comment why we set allocated_file_size to -ENOTSUP after write [Fam]
- avoid segfault when parsing filname [Fam]
- remove unused close_bh from NFSClient [Fam]
- avoid dividing and mutliplying total_size by BDRV_SECTOR_SIZE in
nfs_file_create [Fam]
MAINTAINERS | 5 +
block/Makefile.objs | 1 +
block/nfs.c | 402 +++++++++++++++++++++++++++++++++++++++++++++++++++
configure | 26 ++++
4 files changed, 434 insertions(+)
create mode 100644 block/nfs.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a5ab8f8..09996ab 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -935,6 +935,11 @@ M: Peter Lieven <p...@kamp.de>
S: Supported
F: block/iscsi.c
+NFS
+M: Peter Lieven <p...@kamp.de>
+S: Maintained
+F: block/nfs.c
+
SSH
M: Richard W.M. Jones <rjo...@redhat.com>
S: Supported
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/nfs.c b/block/nfs.c
new file mode 100644
index 0000000..5d34565
--- /dev/null
+++ b/block/nfs.c
@@ -0,0 +1,402 @@
+/*
+ * QEMU Block driver for native access to files on NFS shares
+ *
+ * Copyright (c) 2013 Peter Lieven <p...@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-zdr.h>
+#include <nfsc/libnfs.h>
+#include <nfsc/libnfs-raw.h>
+#include <nfsc/libnfs-raw-mount.h>
+
+typedef struct NFSClient {
+ struct nfs_context *context;
+ struct nfsfh *fh;
+ int events;
+ bool has_zero_init;
+ int64_t allocated_file_size;
+} NFSClient;
+
+typedef struct NFSRPC {
+ int status;
+ int complete;
+ QEMUIOVector *iov;
+ 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 status, struct nfs_context *nfs, void *data,
+ void *private_data)
+{
+ NFSRPC *task = private_data;
+ task->complete = 1;
+ task->status = status;
+ if (task->status > 0 && task->iov) {
+ if (task->status <= task->iov->size) {
+ qemu_iovec_from_buf(task->iov, 0, data, task->status);
+ } else {
+ task->status = -EIO;
+ }
+ }
+ 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.status < 0) {
+ return task.status;
+ }
+
+ 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.status != nb_sectors * BDRV_SECTOR_SIZE) {
+ return task.status < 0 ? task.status : -EIO;
+ }
+
+ /* set to -ENOTSUP since bdrv_allocated_file_size is only used
+ * in qemu-img open. So we can use the cached value for allocate
+ * filesize obtained from fstat at open time */
+ client->allocated_file_size = -ENOTSUP;
+ 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.status;
+}
+
+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;
+ URI *uri;
+ char *file = NULL, *strp = NULL;
+ struct stat st;
+
+ uri = uri_parse(filename);
+ if (!uri) {
+ error_setg(errp, "Invalid URL specified.\n");
+ goto fail;
+ }
+ strp = strrchr(uri->path, '/');
+ if (strp == NULL) {
+ error_setg(errp, "Invalid URL specified.\n");
+ 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;
+ }
+
+ 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);
+ client->allocated_file_size = st.st_blocks * st.st_blksize;
+ goto out;
+fail:
+ nfs_client_close(client);
+out:
+ 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_nofail(&runtime_opts);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (error_is_set(&local_err)) {
+ qerror_report_err(local_err);
+ error_free(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 *filename, 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, filename, O_CREAT, errp);
+ if (ret < 0) {
+ goto out;
+ }
+ ret = nfs_ftruncate(client->context, client->fh, total_size);
+out:
+ nfs_client_close(client);
+ 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;
+ return client->allocated_file_size;
+}
+
+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/configure b/configure
index d97556c..bae1d2b 100755
--- a/configure
+++ b/configure
@@ -251,6 +251,7 @@ vss_win32_sdk=""
win_sdk="no"
want_tools="yes"
libiscsi=""
+libnfs=""
coroutine=""
coroutine_pool=""
seccomp=""
@@ -839,6 +840,10 @@ for opt do
;;
--enable-libiscsi) libiscsi="yes"
;;
+ --disable-libnfs) libnfs="no"
+ ;;
+ --enable-libnfs) libnfs="yes"
+ ;;
--enable-profiler) profiler="yes"
;;
--disable-cocoa) cocoa="no"
@@ -1210,6 +1215,8 @@ echo " --enable-spice enable spice"
echo " --enable-rbd enable building the rados block device (rbd)"
echo " --disable-libiscsi disable iscsi support"
echo " --enable-libiscsi enable iscsi support"
+echo " --disable-libnfs disable nfs support"
+echo " --enable-libnfs enable nfs support"
echo " --disable-smartcard-nss disable smartcard nss support"
echo " --enable-smartcard-nss enable smartcard nss support"
echo " --disable-libusb disable libusb (for usb passthrough)"
@@ -3596,6 +3603,20 @@ 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 $pkg_config --atleast-version=1.8.0 libnfs; then
+ libnfs="yes"
+ libnfs_libs=$($pkg_config --libs libnfs)
+ LIBS="$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
@@ -3825,6 +3846,7 @@ 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 $seccomp"
@@ -4161,6 +4183,10 @@ if test "$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
--
1.7.9.5
