From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38597) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W9CP1-0007m1-NT for qemu-devel@nongnu.org; Fri, 31 Jan 2014 06:37:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W9COt-0007FR-53 for qemu-devel@nongnu.org; Fri, 31 Jan 2014 06:36:55 -0500 Received: from mx.ipv6.kamp.de ([2a02:248:0:51::16]:32911 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W9COs-0007E7-Mh for qemu-devel@nongnu.org; Fri, 31 Jan 2014 06:36:47 -0500 Message-ID: <52EB8ABD.6070208@kamp.de> Date: Fri, 31 Jan 2014 12:36:29 +0100 From: Peter Lieven MIME-Version: 1.0 References: <1390985425-13165-1-git-send-email-pl@kamp.de> <1390985425-13165-2-git-send-email-pl@kamp.de> <20140129161959.GG3079@irqsave.net> In-Reply-To: <20140129161959.GG3079@irqsave.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCHv7 1/5] block: add native support for NFS List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?ISO-8859-1?Q?Beno=EEt_Canet?= Cc: Kevin Wolf , Fam Zheng , Stefan Hajnoczi , Jeff Cody , qemu-devel@nongnu.org, Max Reitz , owasserm@redhat.com, Federico Simoncelli , ronniesahlberg@gmail.com, Wenchao Xia 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:////[?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 >> --- >> 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 >> S: Supported >> F: block/iscsi.c >> >> +NFS >> +M: Peter Lieven >> +S: Maintained >> +F: block/nfs.c >> + >> SSH >> M: Richard W.M. Jones >> 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 >> + * >> + * 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 >> +#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 >> + >> +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 ? it doesn't matter nfs_client_close can be called with client->context == NULL. Sorry I entirely missed your other comments. Peter