qemu/block/nfs.c
Kevin Wolf 92b92799dc block: Add flags to BlockDriver.bdrv_co_truncate()
This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState that allows drivers to advertise support for request
flags in the context of truncate.

For now, we always pass 0 and no drivers declare support for any flag.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30 17:51:07 +02:00

908 lines
26 KiB
C

/*
* QEMU Block driver for native access to files on NFS shares
*
* Copyright (c) 2014-2017 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 "qemu/osdep.h"
#include <poll.h>
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "block/block_int.h"
#include "block/qdict.h"
#include "trace.h"
#include "qemu/iov.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qemu/uri.h"
#include "qemu/cutils.h"
#include "sysemu/sysemu.h"
#include "sysemu/replay.h"
#include "qapi/qapi-visit-block-core.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qobject-output-visitor.h"
#include <nfsc/libnfs.h>
#define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
#define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
#define QEMU_NFS_MAX_DEBUG_LEVEL 2
typedef struct NFSClient {
struct nfs_context *context;
struct nfsfh *fh;
int events;
bool has_zero_init;
AioContext *aio_context;
QemuMutex mutex;
blkcnt_t st_blocks;
bool cache_used;
NFSServer *server;
char *path;
int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug;
} NFSClient;
typedef struct NFSRPC {
BlockDriverState *bs;
int ret;
int complete;
QEMUIOVector *iov;
struct stat *st;
Coroutine *co;
NFSClient *client;
} NFSRPC;
static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
{
URI *uri = NULL;
QueryParams *qp = NULL;
int ret = -EINVAL, i;
uri = uri_parse(filename);
if (!uri) {
error_setg(errp, "Invalid URI specified");
goto out;
}
if (g_strcmp0(uri->scheme, "nfs") != 0) {
error_setg(errp, "URI scheme must be 'nfs'");
goto out;
}
if (!uri->server) {
error_setg(errp, "missing hostname in URI");
goto out;
}
if (!uri->path) {
error_setg(errp, "missing file path in URI");
goto out;
}
qp = query_params_parse(uri->query);
if (!qp) {
error_setg(errp, "could not parse query parameters");
goto out;
}
qdict_put_str(options, "server.host", uri->server);
qdict_put_str(options, "server.type", "inet");
qdict_put_str(options, "path", uri->path);
for (i = 0; i < qp->n; i++) {
unsigned long long val;
if (!qp->p[i].value) {
error_setg(errp, "Value for NFS parameter expected: %s",
qp->p[i].name);
goto out;
}
if (parse_uint_full(qp->p[i].value, &val, 0)) {
error_setg(errp, "Illegal value for NFS parameter: %s",
qp->p[i].name);
goto out;
}
if (!strcmp(qp->p[i].name, "uid")) {
qdict_put_str(options, "user", qp->p[i].value);
} else if (!strcmp(qp->p[i].name, "gid")) {
qdict_put_str(options, "group", qp->p[i].value);
} else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
qdict_put_str(options, "tcp-syn-count", qp->p[i].value);
} else if (!strcmp(qp->p[i].name, "readahead")) {
qdict_put_str(options, "readahead-size", qp->p[i].value);
} else if (!strcmp(qp->p[i].name, "pagecache")) {
qdict_put_str(options, "page-cache-size", qp->p[i].value);
} else if (!strcmp(qp->p[i].name, "debug")) {
qdict_put_str(options, "debug", qp->p[i].value);
} else {
error_setg(errp, "Unknown NFS parameter name: %s",
qp->p[i].name);
goto out;
}
}
ret = 0;
out:
if (qp) {
query_params_free(qp);
}
if (uri) {
uri_free(uri);
}
return ret;
}
static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
{
const QDictEntry *qe;
for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
if (!strcmp(qe->key, "host") ||
!strcmp(qe->key, "path") ||
!strcmp(qe->key, "user") ||
!strcmp(qe->key, "group") ||
!strcmp(qe->key, "tcp-syn-count") ||
!strcmp(qe->key, "readahead-size") ||
!strcmp(qe->key, "page-cache-size") ||
!strcmp(qe->key, "debug") ||
strstart(qe->key, "server.", NULL))
{
error_setg(errp, "Option %s cannot be used with a filename",
qe->key);
return true;
}
}
return false;
}
static void nfs_parse_filename(const char *filename, QDict *options,
Error **errp)
{
if (nfs_has_filename_options_conflict(options, errp)) {
return;
}
nfs_parse_uri(filename, options, errp);
}
static void nfs_process_read(void *arg);
static void nfs_process_write(void *arg);
/* Called with QemuMutex held. */
static void nfs_set_events(NFSClient *client)
{
int ev = nfs_which_events(client->context);
if (ev != client->events) {
aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
false,
(ev & POLLIN) ? nfs_process_read : NULL,
(ev & POLLOUT) ? nfs_process_write : NULL,
NULL, client);
}
client->events = ev;
}
static void nfs_process_read(void *arg)
{
NFSClient *client = arg;
qemu_mutex_lock(&client->mutex);
nfs_service(client->context, POLLIN);
nfs_set_events(client);
qemu_mutex_unlock(&client->mutex);
}
static void nfs_process_write(void *arg)
{
NFSClient *client = arg;
qemu_mutex_lock(&client->mutex);
nfs_service(client->context, POLLOUT);
nfs_set_events(client);
qemu_mutex_unlock(&client->mutex);
}
static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
{
*task = (NFSRPC) {
.co = qemu_coroutine_self(),
.bs = bs,
.client = bs->opaque,
};
}
static void nfs_co_generic_bh_cb(void *opaque)
{
NFSRPC *task = opaque;
task->complete = 1;
aio_co_wake(task->co);
}
/* Called (via nfs_service) with QemuMutex held. */
static void
nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
void *private_data)
{
NFSRPC *task = private_data;
task->ret = ret;
assert(!task->st);
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) {
error_report("NFS Error: %s", nfs_get_error(nfs));
}
replay_bh_schedule_oneshot_event(task->client->aio_context,
nfs_co_generic_bh_cb, task);
}
static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *iov,
int flags)
{
NFSClient *client = bs->opaque;
NFSRPC task;
nfs_co_init_task(bs, &task);
task.iov = iov;
qemu_mutex_lock(&client->mutex);
if (nfs_pread_async(client->context, client->fh,
offset, bytes, nfs_co_generic_cb, &task) != 0) {
qemu_mutex_unlock(&client->mutex);
return -ENOMEM;
}
nfs_set_events(client);
qemu_mutex_unlock(&client->mutex);
while (!task.complete) {
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_pwritev(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *iov,
int flags)
{
NFSClient *client = bs->opaque;
NFSRPC task;
char *buf = NULL;
bool my_buffer = false;
nfs_co_init_task(bs, &task);
if (iov->niov != 1) {
buf = g_try_malloc(bytes);
if (bytes && buf == NULL) {
return -ENOMEM;
}
qemu_iovec_to_buf(iov, 0, buf, bytes);
my_buffer = true;
} else {
buf = iov->iov[0].iov_base;
}
qemu_mutex_lock(&client->mutex);
if (nfs_pwrite_async(client->context, client->fh,
offset, bytes, buf,
nfs_co_generic_cb, &task) != 0) {
qemu_mutex_unlock(&client->mutex);
if (my_buffer) {
g_free(buf);
}
return -ENOMEM;
}
nfs_set_events(client);
qemu_mutex_unlock(&client->mutex);
while (!task.complete) {
qemu_coroutine_yield();
}
if (my_buffer) {
g_free(buf);
}
if (task.ret != bytes) {
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(bs, &task);
qemu_mutex_lock(&client->mutex);
if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
&task) != 0) {
qemu_mutex_unlock(&client->mutex);
return -ENOMEM;
}
nfs_set_events(client);
qemu_mutex_unlock(&client->mutex);
while (!task.complete) {
qemu_coroutine_yield();
}
return task.ret;
}
static void nfs_detach_aio_context(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
false, NULL, NULL, NULL, NULL);
client->events = 0;
}
static void nfs_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
NFSClient *client = bs->opaque;
client->aio_context = new_context;
nfs_set_events(client);
}
static void nfs_client_close(NFSClient *client)
{
if (client->context) {
qemu_mutex_lock(&client->mutex);
aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
false, NULL, NULL, NULL, NULL);
qemu_mutex_unlock(&client->mutex);
if (client->fh) {
nfs_close(client->context, client->fh);
client->fh = NULL;
}
#ifdef LIBNFS_FEATURE_UMOUNT
nfs_umount(client->context);
#endif
nfs_destroy_context(client->context);
client->context = NULL;
}
g_free(client->path);
qemu_mutex_destroy(&client->mutex);
qapi_free_NFSServer(client->server);
client->server = NULL;
}
static void nfs_file_close(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
nfs_client_close(client);
}
static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts,
int flags, int open_flags, Error **errp)
{
int64_t ret = -EINVAL;
struct stat st;
char *file = NULL, *strp = NULL;
qemu_mutex_init(&client->mutex);
client->path = g_strdup(opts->path);
strp = strrchr(client->path, '/');
if (strp == NULL) {
error_setg(errp, "Invalid URL specified");
goto fail;
}
file = g_strdup(strp);
*strp = 0;
/* Steal the NFSServer object from opts; set the original pointer to NULL
* to avoid use after free and double free. */
client->server = opts->server;
opts->server = NULL;
client->context = nfs_init_context();
if (client->context == NULL) {
error_setg(errp, "Failed to init NFS context");
goto fail;
}
if (opts->has_user) {
client->uid = opts->user;
nfs_set_uid(client->context, client->uid);
}
if (opts->has_group) {
client->gid = opts->group;
nfs_set_gid(client->context, client->gid);
}
if (opts->has_tcp_syn_count) {
client->tcp_syncnt = opts->tcp_syn_count;
nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
}
#ifdef LIBNFS_FEATURE_READAHEAD
if (opts->has_readahead_size) {
if (open_flags & BDRV_O_NOCACHE) {
error_setg(errp, "Cannot enable NFS readahead "
"if cache.direct = on");
goto fail;
}
client->readahead = opts->readahead_size;
if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
warn_report("Truncating NFS readahead size to %d",
QEMU_NFS_MAX_READAHEAD_SIZE);
client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
}
nfs_set_readahead(client->context, client->readahead);
#ifdef LIBNFS_FEATURE_PAGECACHE
nfs_set_pagecache_ttl(client->context, 0);
#endif
client->cache_used = true;
}
#endif
#ifdef LIBNFS_FEATURE_PAGECACHE
if (opts->has_page_cache_size) {
if (open_flags & BDRV_O_NOCACHE) {
error_setg(errp, "Cannot enable NFS pagecache "
"if cache.direct = on");
goto fail;
}
client->pagecache = opts->page_cache_size;
if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
warn_report("Truncating NFS pagecache size to %d pages",
QEMU_NFS_MAX_PAGECACHE_SIZE);
client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
}
nfs_set_pagecache(client->context, client->pagecache);
nfs_set_pagecache_ttl(client->context, 0);
client->cache_used = true;
}
#endif
#ifdef LIBNFS_FEATURE_DEBUG
if (opts->has_debug) {
client->debug = opts->debug;
/* limit the maximum debug level to avoid potential flooding
* of our log files. */
if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
warn_report("Limiting NFS debug level to %d",
QEMU_NFS_MAX_DEBUG_LEVEL);
client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
}
nfs_set_debug(client->context, client->debug);
}
#endif
ret = nfs_mount(client->context, client->server->host, client->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->st_blocks = st.st_blocks;
client->has_zero_init = S_ISREG(st.st_mode);
*strp = '/';
goto out;
fail:
nfs_client_close(client);
out:
g_free(file);
return ret;
}
static BlockdevOptionsNfs *nfs_options_qdict_to_qapi(QDict *options,
Error **errp)
{
BlockdevOptionsNfs *opts = NULL;
Visitor *v;
const QDictEntry *e;
Error *local_err = NULL;
v = qobject_input_visitor_new_flat_confused(options, errp);
if (!v) {
return NULL;
}
visit_type_BlockdevOptionsNfs(v, NULL, &opts, &local_err);
visit_free(v);
if (local_err) {
error_propagate(errp, local_err);
return NULL;
}
/* Remove the processed options from the QDict (the visitor processes
* _all_ options in the QDict) */
while ((e = qdict_first(options))) {
qdict_del(options, e->key);
}
return opts;
}
static int64_t nfs_client_open_qdict(NFSClient *client, QDict *options,
int flags, int open_flags, Error **errp)
{
BlockdevOptionsNfs *opts;
int ret;
opts = nfs_options_qdict_to_qapi(options, errp);
if (opts == NULL) {
ret = -EINVAL;
goto fail;
}
ret = nfs_client_open(client, opts, flags, open_flags, errp);
fail:
qapi_free_BlockdevOptionsNfs(opts);
return ret;
}
static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp) {
NFSClient *client = bs->opaque;
int64_t ret;
client->aio_context = bdrv_get_aio_context(bs);
ret = nfs_client_open_qdict(client, options,
(flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
bs->open_flags, errp);
if (ret < 0) {
return ret;
}
bs->total_sectors = ret;
ret = 0;
return ret;
}
static QemuOptsList nfs_create_opts = {
.name = "nfs-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
{ /* end of list */ }
}
};
static int nfs_file_co_create(BlockdevCreateOptions *options, Error **errp)
{
BlockdevCreateOptionsNfs *opts = &options->u.nfs;
NFSClient *client = g_new0(NFSClient, 1);
int ret;
assert(options->driver == BLOCKDEV_DRIVER_NFS);
client->aio_context = qemu_get_aio_context();
ret = nfs_client_open(client, opts->location, O_CREAT, 0, errp);
if (ret < 0) {
goto out;
}
ret = nfs_ftruncate(client->context, client->fh, opts->size);
nfs_client_close(client);
out:
g_free(client);
return ret;
}
static int coroutine_fn nfs_file_co_create_opts(BlockDriver *drv,
const char *url,
QemuOpts *opts,
Error **errp)
{
BlockdevCreateOptions *create_options;
BlockdevCreateOptionsNfs *nfs_opts;
QDict *options;
int ret;
create_options = g_new0(BlockdevCreateOptions, 1);
create_options->driver = BLOCKDEV_DRIVER_NFS;
nfs_opts = &create_options->u.nfs;
/* Read out options */
nfs_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
options = qdict_new();
ret = nfs_parse_uri(url, options, errp);
if (ret < 0) {
goto out;
}
nfs_opts->location = nfs_options_qdict_to_qapi(options, errp);
if (nfs_opts->location == NULL) {
ret = -EINVAL;
goto out;
}
ret = nfs_file_co_create(create_options, errp);
if (ret < 0) {
goto out;
}
ret = 0;
out:
qobject_unref(options);
qapi_free_BlockdevCreateOptions(create_options);
return ret;
}
static int nfs_has_zero_init(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
return client->has_zero_init;
}
/* Called (via nfs_service) with QemuMutex held. */
static void
nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
void *private_data)
{
NFSRPC *task = private_data;
task->ret = ret;
if (task->ret == 0) {
memcpy(task->st, data, sizeof(struct stat));
}
if (task->ret < 0) {
error_report("NFS Error: %s", nfs_get_error(nfs));
}
/* Set task->complete before reading bs->wakeup. */
atomic_mb_set(&task->complete, 1);
bdrv_wakeup(task->bs);
}
static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
NFSRPC task = {0};
struct stat st;
if (bdrv_is_read_only(bs) &&
!(bs->open_flags & BDRV_O_NOCACHE)) {
return client->st_blocks * 512;
}
task.bs = bs;
task.st = &st;
if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
&task) != 0) {
return -ENOMEM;
}
nfs_set_events(client);
BDRV_POLL_WHILE(bs, !task.complete);
return (task.ret < 0 ? task.ret : st.st_blocks * 512);
}
static int coroutine_fn
nfs_file_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
PreallocMode prealloc, BdrvRequestFlags flags,
Error **errp)
{
NFSClient *client = bs->opaque;
int ret;
if (prealloc != PREALLOC_MODE_OFF) {
error_setg(errp, "Unsupported preallocation mode '%s'",
PreallocMode_str(prealloc));
return -ENOTSUP;
}
ret = nfs_ftruncate(client->context, client->fh, offset);
if (ret < 0) {
error_setg_errno(errp, -ret, "Failed to truncate file");
return ret;
}
return 0;
}
/* Note that this will not re-establish a connection with the NFS server
* - it is effectively a NOP. */
static int nfs_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
NFSClient *client = state->bs->opaque;
struct stat st;
int ret = 0;
if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
error_setg(errp, "Cannot open a read-only mount as read-write");
return -EACCES;
}
if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
error_setg(errp, "Cannot disable cache if libnfs readahead or"
" pagecache is enabled");
return -EINVAL;
}
/* Update cache for read-only reopens */
if (!(state->flags & BDRV_O_RDWR)) {
ret = nfs_fstat(client->context, client->fh, &st);
if (ret < 0) {
error_setg(errp, "Failed to fstat file: %s",
nfs_get_error(client->context));
return ret;
}
client->st_blocks = st.st_blocks;
}
return 0;
}
static void nfs_refresh_filename(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
if (client->uid && !client->gid) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
client->uid);
} else if (!client->uid && client->gid) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
client->gid);
} else if (client->uid && client->gid) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
client->server->host, client->path, client->uid, client->gid);
} else {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nfs://%s%s", client->server->host, client->path);
}
}
static char *nfs_dirname(BlockDriverState *bs, Error **errp)
{
NFSClient *client = bs->opaque;
if (client->uid || client->gid) {
bdrv_refresh_filename(bs);
error_setg(errp, "Cannot generate a base directory for NFS node '%s'",
bs->filename);
return NULL;
}
return g_strdup_printf("nfs://%s%s/", client->server->host, client->path);
}
#ifdef LIBNFS_FEATURE_PAGECACHE
static void coroutine_fn nfs_co_invalidate_cache(BlockDriverState *bs,
Error **errp)
{
NFSClient *client = bs->opaque;
nfs_pagecache_invalidate(client->context, client->fh);
}
#endif
static const char *nfs_strong_runtime_opts[] = {
"path",
"user",
"group",
"server.",
NULL
};
static BlockDriver bdrv_nfs = {
.format_name = "nfs",
.protocol_name = "nfs",
.instance_size = sizeof(NFSClient),
.bdrv_parse_filename = nfs_parse_filename,
.create_opts = &nfs_create_opts,
.bdrv_has_zero_init = nfs_has_zero_init,
.bdrv_has_zero_init_truncate = nfs_has_zero_init,
.bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
.bdrv_co_truncate = nfs_file_co_truncate,
.bdrv_file_open = nfs_file_open,
.bdrv_close = nfs_file_close,
.bdrv_co_create = nfs_file_co_create,
.bdrv_co_create_opts = nfs_file_co_create_opts,
.bdrv_reopen_prepare = nfs_reopen_prepare,
.bdrv_co_preadv = nfs_co_preadv,
.bdrv_co_pwritev = nfs_co_pwritev,
.bdrv_co_flush_to_disk = nfs_co_flush,
.bdrv_detach_aio_context = nfs_detach_aio_context,
.bdrv_attach_aio_context = nfs_attach_aio_context,
.bdrv_refresh_filename = nfs_refresh_filename,
.bdrv_dirname = nfs_dirname,
.strong_runtime_opts = nfs_strong_runtime_opts,
#ifdef LIBNFS_FEATURE_PAGECACHE
.bdrv_co_invalidate_cache = nfs_co_invalidate_cache,
#endif
};
static void nfs_block_init(void)
{
bdrv_register(&bdrv_nfs);
}
block_init(nfs_block_init);