> Am 17.12.2013 um 17:53 schrieb ronnie sahlberg <ronniesahlb...@gmail.com>:
>
> NFSTask
>
> Task is a very scsi-ish term. Maybe RPC is better ?
>
> NFSrpc ?
will change it in v3
>
>
>
>> On Tue, Dec 17, 2013 at 1:15 AM, Peter Lieven <p...@kamp.de> wrote:
>> 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.
>>
>> Signed-off-by: Peter Lieven <p...@kamp.de>
>> ---
>> 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 | 419
>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>> configure | 38 +++++
>> 4 files changed, 463 insertions(+)
>> create mode 100644 block/nfs.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index c19133f..f53d184 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -899,6 +899,11 @@ 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 f43ecbc..aa8eaf9 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 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..006b8cc
>> --- /dev/null
>> +++ b/block/nfs.c
>> @@ -0,0 +1,419 @@
>> +/*
>> + * 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 "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 NFSTask {
>> + int status;
>> + int complete;
>> + QEMUIOVector *iov;
>> + Coroutine *co;
>> + QEMUBH *bh;
>> +} NFSTask;
>> +
>> +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, NFSTask *Task)
>> +{
>> + *Task = (NFSTask) {
>> + .co = qemu_coroutine_self(),
>> + };
>> +}
>> +
>> +static void nfs_co_generic_bh_cb(void *opaque)
>> +{
>> + NFSTask *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)
>> +{
>> + NFSTask *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;
>> + NFSTask 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 -EIO;
>> + }
>> +
>> + 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;
>> + NFSTask 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 -EIO;
>> + }
>> +
>> + 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;
>> + }
>> +
>> + bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
>> + /* 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;
>> + NFSTask task;
>> +
>> + nfs_co_init_task(client, &task);
>> +
>> + if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
>> + &task) != 0) {
>> + return -EIO;
>> + }
>> +
>> + 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_file_close(BlockDriverState *bs)
>> +{
>> + NFSClient *client = bs->opaque;
>> + 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 int nfs_file_open_common(BlockDriverState *bs, QDict *options, int
>> flags,
>> + int open_flags, Error **errp)
>> +{
>> + NFSClient *client = bs->opaque;
>> + const char *filename;
>> + int ret = 0;
>> + QemuOpts *opts;
>> + Error *local_err = NULL;
>> + char *server = NULL, *path = NULL, *file = NULL, *strp;
>> + struct stat st;
>> +
>> + 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);
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> +
>> + filename = qemu_opt_get(opts, "filename");
>> +
>> + client->context = nfs_init_context();
>> +
>> + if (client->context == NULL) {
>> + error_setg(errp, "Failed to init NFS context");
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> +
>> + if (strlen(filename) <= 6) {
>> + error_setg(errp, "Invalid server in URL");
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> +
>> + server = g_strdup(filename + 6);
>> + if (server[0] == '/' || server[0] == '\0') {
>> + error_setg(errp, "Invalid server in URL");
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> + strp = strchr(server, '/');
>> + if (strp == NULL) {
>> + error_setg(errp, "Invalid URL specified.\n");
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> + path = g_strdup(strp);
>> + *strp = 0;
>> + strp = strrchr(path, '/');
>> + if (strp == NULL) {
>> + error_setg(errp, "Invalid URL specified.\n");
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> + file = g_strdup(strp);
>> + *strp = 0;
>> +
>> + ret = nfs_mount(client->context, server, path);
>> + if (ret < 0) {
>> + error_setg(errp, "Failed to mount nfs share: %s",
>> + nfs_get_error(client->context));
>> + goto fail;
>> + }
>> +
>> + if (open_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 {
>> + open_flags = (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY;
>> + ret = nfs_open(client->context, file, open_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;
>> + }
>> +
>> + /* TODO allow reading beyond EOF */
>> + bs->total_sectors = 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_file_close(bs);
>> +out:
>> + g_free(server);
>> + g_free(path);
>> + g_free(file);
>> + return ret;
>> +}
>> +
>> +static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
>> + Error **errp) {
>> + return nfs_file_open_common(bs, options, flags, 0, errp);
>> +}
>> +
>> +static int nfs_file_create(const char *filename, QEMUOptionParameter
>> *options,
>> + Error **errp)
>> +{
>> + int ret = 0;
>> + int64_t total_size = 0;
>> + BlockDriverState *bs;
>> + NFSClient *client = NULL;
>> + QDict *bs_options;
>> +
>> + bs = bdrv_new("");
>> +
>> + /* Read out options */
>> + while (options && options->name) {
>> + if (!strcmp(options->name, "size")) {
>> + total_size = options->value.n;
>> + }
>> + options++;
>> + }
>> +
>> + bs->opaque = g_malloc0(sizeof(NFSClient));
>> + client = bs->opaque;
>> +
>> + bs_options = qdict_new();
>> + qdict_put(bs_options, "filename", qstring_from_str(filename));
>> + ret = nfs_file_open_common(bs, bs_options, 0, O_CREAT, NULL);
>> + QDECREF(bs_options);
>> + if (ret < 0) {
>> + goto out;
>> + }
>> + ret = nfs_ftruncate(client->context, client->fh, total_size);
>> +out:
>> + nfs_file_close(bs);
>> + g_free(bs->opaque);
>> + bs->opaque = NULL;
>> + bdrv_unref(bs);
>> + 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 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_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 8144d9f..6c9e47a 100755
>> --- a/configure
>> +++ b/configure
>> @@ -250,6 +250,7 @@ vss_win32_sdk=""
>> win_sdk="no"
>> want_tools="yes"
>> libiscsi=""
>> +libnfs=""
>> coroutine=""
>> coroutine_pool=""
>> seccomp=""
>> @@ -833,6 +834,10 @@ for opt do
>> ;;
>> --enable-libiscsi) libiscsi="yes"
>> ;;
>> + --disable-libnfs) libnfs="no"
>> + ;;
>> + --enable-libnfs) libnfs="yes"
>> + ;;
>> --enable-profiler) profiler="yes"
>> ;;
>> --disable-cocoa) cocoa="no"
>> @@ -1202,6 +1207,8 @@ 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)"
>> @@ -3050,6 +3057,32 @@ EOF
>> fi
>> fi
>>
>> +##########################################
>> +# Do we have libnfs
>> +if test "$libnfs" != "no" ; then
>> + cat > $TMPC << EOF
>> +#include <nfsc/libnfs-zdr.h>
>> +#include <nfsc/libnfs.h>
>> +#include <nfsc/libnfs-raw.h>
>> +#include <nfsc/libnfs-raw-mount.h>
>> +int main(void) {
>> + nfs_init_context();
>> + nfs_pread_async(0,0,0,0,0,0);
>> + nfs_pwrite_async(0,0,0,0,0,0,0);
>> + nfs_fstat(0,0,0);
>> + return 0;
>> + }
>> +EOF
>> + if compile_prog "-Werror" "-lnfs" ; then
>> + libnfs="yes"
>> + LIBS="$LIBS -lnfs"
>> + else
>> + if test "$libnfs" = "yes" ; then
>> + feature_not_found "libnfs"
>> + fi
>> + libnfs="no"
>> + fi
>> +fi
>>
>> ##########################################
>> # Do we need libm
>> @@ -3777,6 +3810,7 @@ echo "libusb $libusb"
>> echo "usb net redir $usb_redir"
>> echo "GLX support $glx"
>> echo "libiscsi support $libiscsi"
>> +echo "libnfs support $libnfs"
>> echo "build guest agent $guest_agent"
>> echo "QGA VSS support $guest_agent_with_vss"
>> echo "seccomp support $seccomp"
>> @@ -4107,6 +4141,10 @@ if test "$libiscsi" = "yes" ; then
>> echo "CONFIG_LIBISCSI=y" >> $config_host_mak
>> fi
>>
>> +if test "$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
>>
>>
