On Wed, Jan 29, 2014 at 05:38:29PM +0100, Peter Lieven wrote: > On 29.01.2014 17:19, Benoît Canet wrote: > >Le Wednesday 29 Jan 2014 à 09:50:21 (+0100), Peter Lieven a écrit : > >>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>[?param=value[¶m2=value2[&...]]] > >> > >>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. > >> > >>For additional information on ROOT vs. non-ROOT operation and URL > >>format + parameters see: > >> https://raw.github.com/sahlberg/libnfs/master/README > >> > >>Supported by qemu are the uid, gid and tcp-syncnt URL parameters. > >> > >>LibNFS currently support NFS version 3 only. > >> > >>Signed-off-by: Peter Lieven <p...@kamp.de> > >>--- > >> MAINTAINERS | 5 + > >> block/Makefile.objs | 1 + > >> block/nfs.c | 440 > >> +++++++++++++++++++++++++++++++++++++++++++++++++++ > >> configure | 26 +++ > >> qapi-schema.json | 1 + > >> 5 files changed, 473 insertions(+) > >> create mode 100644 block/nfs.c > >> > >>diff --git a/MAINTAINERS b/MAINTAINERS > >>index fb53242..f8411f9 100644 > >>--- a/MAINTAINERS > >>+++ b/MAINTAINERS > >>@@ -936,6 +936,11 @@ 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..2bbf7a2 > >>--- /dev/null > >>+++ b/block/nfs.c > >>@@ -0,0 +1,440 @@ > >>+/* > >>+ * QEMU Block driver for native access to files on NFS shares > >>+ * > >>+ * Copyright (c) 2014 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.h> > >>+ > >>+typedef struct NFSClient { > >>+ struct nfs_context *context; > >>+ struct nfsfh *fh; > >>+ int events; > >>+ bool has_zero_init; > >>+} NFSClient; > >>+ > >>+typedef struct NFSRPC { > >>+ int status; > >>+ 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 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) { > >It feel very odd to compare something named status with something named size. > > > >>+ qemu_iovec_from_buf(task->iov, 0, data, task->status); > >>+ } else { > >>+ task->status = -EIO; > >>+ } > >>+ } > >>+ if (task->status == 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.status < 0) { > >>+ return task.status; > >>+ } > >>+ > >>+ /* zero pad short reads */ > >>+ if (task.status < iov->size) { > >>+ qemu_iovec_memset(iov, task.status, 0, iov->size - 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; > >>+ } > >>+ > >>+ 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; > >>+} > >>+ > >>+/* 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_.cilclient_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; > >Should this be goto out since we don't have done nfs_init_context yet ? > >>+ } > >>+ strp = strrchr(uri->path, '/'); > >>+ if (strp == NULL) { > >>+ error_setg(errp, "Invalid URL specified"); > >>+ goto fail; > >goto out ? > >>+ } > >>+ 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)) { > >>+ qerror_report_err(local_err); > >I have seen more usage of error_propagate(errp, local_err); in QEMU code. > >Maybe I am missing the point. > > > >>+ 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 *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); > >>+out: > >Should the out: label be after nfs_client_close(client); since the code will > >jump to it on nfs_client_open failure ? > You are right, but it doesn't hurt since you can call nfs_client_close > multiple > times.
Will you send another revision addressing the other comments? Stefan
