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qemu/block/rbd.c
Max Reitz c80d8b06cf block: Add @exact parameter to bdrv_co_truncate() 
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:00:07 +01:00

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/*
* QEMU Block driver for RADOS (Ceph)
*
* Copyright (C) 2010-2011 Christian Brunner <chb@muc.de>,
* Josh Durgin <josh.durgin@dreamhost.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include <rbd/librbd.h>
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "block/block_int.h"
#include "block/qdict.h"
#include "crypto/secret.h"
#include "qemu/cutils.h"
#include "sysemu/replay.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qapi-visit-block-core.h"
/*
* When specifying the image filename use:
*
* rbd:poolname/devicename[@snapshotname][:option1=value1[:option2=value2...]]
*
* poolname must be the name of an existing rados pool.
*
* devicename is the name of the rbd image.
*
* Each option given is used to configure rados, and may be any valid
* Ceph option, "id", or "conf".
*
* The "id" option indicates what user we should authenticate as to
* the Ceph cluster. If it is excluded we will use the Ceph default
* (normally 'admin').
*
* The "conf" option specifies a Ceph configuration file to read. If
* it is not specified, we will read from the default Ceph locations
* (e.g., /etc/ceph/ceph.conf). To avoid reading _any_ configuration
* file, specify conf=/dev/null.
*
* Configuration values containing :, @, or = can be escaped with a
* leading "\".
*/
/* rbd_aio_discard added in 0.1.2 */
#if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 2)
#define LIBRBD_SUPPORTS_DISCARD
#else
#undef LIBRBD_SUPPORTS_DISCARD
#endif
#define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)
#define RBD_MAX_SNAPS 100
/* The LIBRBD_SUPPORTS_IOVEC is defined in librbd.h */
#ifdef LIBRBD_SUPPORTS_IOVEC
#define LIBRBD_USE_IOVEC 1
#else
#define LIBRBD_USE_IOVEC 0
#endif
typedef enum {
RBD_AIO_READ,
RBD_AIO_WRITE,
RBD_AIO_DISCARD,
RBD_AIO_FLUSH
} RBDAIOCmd;
typedef struct RBDAIOCB {
BlockAIOCB common;
int64_t ret;
QEMUIOVector *qiov;
char *bounce;
RBDAIOCmd cmd;
int error;
struct BDRVRBDState *s;
} RBDAIOCB;
typedef struct RADOSCB {
RBDAIOCB *acb;
struct BDRVRBDState *s;
int64_t size;
char *buf;
int64_t ret;
} RADOSCB;
typedef struct BDRVRBDState {
rados_t cluster;
rados_ioctx_t io_ctx;
rbd_image_t image;
char *image_name;
char *snap;
uint64_t image_size;
} BDRVRBDState;
static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
BlockdevOptionsRbd *opts, bool cache,
const char *keypairs, const char *secretid,
Error **errp);
static char *qemu_rbd_next_tok(char *src, char delim, char **p)
{
char *end;
*p = NULL;
for (end = src; *end; ++end) {
if (*end == delim) {
break;
}
if (*end == '\\' && end[1] != '\0') {
end++;
}
}
if (*end == delim) {
*p = end + 1;
*end = '\0';
}
return src;
}
static void qemu_rbd_unescape(char *src)
{
char *p;
for (p = src; *src; ++src, ++p) {
if (*src == '\\' && src[1] != '\0') {
src++;
}
*p = *src;
}
*p = '\0';
}
static void qemu_rbd_parse_filename(const char *filename, QDict *options,
Error **errp)
{
const char *start;
char *p, *buf;
QList *keypairs = NULL;
char *found_str;
if (!strstart(filename, "rbd:", &start)) {
error_setg(errp, "File name must start with 'rbd:'");
return;
}
buf = g_strdup(start);
p = buf;
found_str = qemu_rbd_next_tok(p, '/', &p);
if (!p) {
error_setg(errp, "Pool name is required");
goto done;
}
qemu_rbd_unescape(found_str);
qdict_put_str(options, "pool", found_str);
if (strchr(p, '@')) {
found_str = qemu_rbd_next_tok(p, '@', &p);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "image", found_str);
found_str = qemu_rbd_next_tok(p, ':', &p);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "snapshot", found_str);
} else {
found_str = qemu_rbd_next_tok(p, ':', &p);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "image", found_str);
}
if (!p) {
goto done;
}
/* The following are essentially all key/value pairs, and we treat
* 'id' and 'conf' a bit special. Key/value pairs may be in any order. */
while (p) {
char *name, *value;
name = qemu_rbd_next_tok(p, '=', &p);
if (!p) {
error_setg(errp, "conf option %s has no value", name);
break;
}
qemu_rbd_unescape(name);
value = qemu_rbd_next_tok(p, ':', &p);
qemu_rbd_unescape(value);
if (!strcmp(name, "conf")) {
qdict_put_str(options, "conf", value);
} else if (!strcmp(name, "id")) {
qdict_put_str(options, "user", value);
} else {
/*
* We pass these internally to qemu_rbd_set_keypairs(), so
* we can get away with the simpler list of [ "key1",
* "value1", "key2", "value2" ] rather than a raw dict
* { "key1": "value1", "key2": "value2" } where we can't
* guarantee order, or even a more correct but complex
* [ { "key1": "value1" }, { "key2": "value2" } ]
*/
if (!keypairs) {
keypairs = qlist_new();
}
qlist_append_str(keypairs, name);
qlist_append_str(keypairs, value);
}
}
if (keypairs) {
qdict_put(options, "=keyvalue-pairs",
qobject_to_json(QOBJECT(keypairs)));
}
done:
g_free(buf);
qobject_unref(keypairs);
return;
}
static void qemu_rbd_refresh_limits(BlockDriverState *bs, Error **errp)
{
/* XXX Does RBD support AIO on less than 512-byte alignment? */
bs->bl.request_alignment = 512;
}
static int qemu_rbd_set_auth(rados_t cluster, BlockdevOptionsRbd *opts,
Error **errp)
{
char *key, *acr;
int r;
GString *accu;
RbdAuthModeList *auth;
if (opts->key_secret) {
key = qcrypto_secret_lookup_as_base64(opts->key_secret, errp);
if (!key) {
return -EIO;
}
r = rados_conf_set(cluster, "key", key);
g_free(key);
if (r < 0) {
error_setg_errno(errp, -r, "Could not set 'key'");
return r;
}
}
if (opts->has_auth_client_required) {
accu = g_string_new("");
for (auth = opts->auth_client_required; auth; auth = auth->next) {
if (accu->str[0]) {
g_string_append_c(accu, ';');
}
g_string_append(accu, RbdAuthMode_str(auth->value));
}
acr = g_string_free(accu, FALSE);
r = rados_conf_set(cluster, "auth_client_required", acr);
g_free(acr);
if (r < 0) {
error_setg_errno(errp, -r,
"Could not set 'auth_client_required'");
return r;
}
}
return 0;
}
static int qemu_rbd_set_keypairs(rados_t cluster, const char *keypairs_json,
Error **errp)
{
QList *keypairs;
QString *name;
QString *value;
const char *key;
size_t remaining;
int ret = 0;
if (!keypairs_json) {
return ret;
}
keypairs = qobject_to(QList,
qobject_from_json(keypairs_json, &error_abort));
remaining = qlist_size(keypairs) / 2;
assert(remaining);
while (remaining--) {
name = qobject_to(QString, qlist_pop(keypairs));
value = qobject_to(QString, qlist_pop(keypairs));
assert(name && value);
key = qstring_get_str(name);
ret = rados_conf_set(cluster, key, qstring_get_str(value));
qobject_unref(value);
if (ret < 0) {
error_setg_errno(errp, -ret, "invalid conf option %s", key);
qobject_unref(name);
ret = -EINVAL;
break;
}
qobject_unref(name);
}
qobject_unref(keypairs);
return ret;
}
static void qemu_rbd_memset(RADOSCB *rcb, int64_t offs)
{
if (LIBRBD_USE_IOVEC) {
RBDAIOCB *acb = rcb->acb;
iov_memset(acb->qiov->iov, acb->qiov->niov, offs, 0,
acb->qiov->size - offs);
} else {
memset(rcb->buf + offs, 0, rcb->size - offs);
}
}
static QemuOptsList runtime_opts = {
.name = "rbd",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = "pool",
.type = QEMU_OPT_STRING,
.help = "Rados pool name",
},
{
.name = "image",
.type = QEMU_OPT_STRING,
.help = "Image name in the pool",
},
{
.name = "conf",
.type = QEMU_OPT_STRING,
.help = "Rados config file location",
},
{
.name = "snapshot",
.type = QEMU_OPT_STRING,
.help = "Ceph snapshot name",
},
{
/* maps to 'id' in rados_create() */
.name = "user",
.type = QEMU_OPT_STRING,
.help = "Rados id name",
},
/*
* server.* extracted manually, see qemu_rbd_mon_host()
*/
{ /* end of list */ }
},
};
/* FIXME Deprecate and remove keypairs or make it available in QMP. */
static int qemu_rbd_do_create(BlockdevCreateOptions *options,
const char *keypairs, const char *password_secret,
Error **errp)
{
BlockdevCreateOptionsRbd *opts = &options->u.rbd;
rados_t cluster;
rados_ioctx_t io_ctx;
int obj_order = 0;
int ret;
assert(options->driver == BLOCKDEV_DRIVER_RBD);
if (opts->location->has_snapshot) {
error_setg(errp, "Can't use snapshot name for image creation");
return -EINVAL;
}
if (opts->has_cluster_size) {
int64_t objsize = opts->cluster_size;
if ((objsize - 1) & objsize) { /* not a power of 2? */
error_setg(errp, "obj size needs to be power of 2");
return -EINVAL;
}
if (objsize < 4096) {
error_setg(errp, "obj size too small");
return -EINVAL;
}
obj_order = ctz32(objsize);
}
ret = qemu_rbd_connect(&cluster, &io_ctx, opts->location, false, keypairs,
password_secret, errp);
if (ret < 0) {
return ret;
}
ret = rbd_create(io_ctx, opts->location->image, opts->size, &obj_order);
if (ret < 0) {
error_setg_errno(errp, -ret, "error rbd create");
goto out;
}
ret = 0;
out:
rados_ioctx_destroy(io_ctx);
rados_shutdown(cluster);
return ret;
}
static int qemu_rbd_co_create(BlockdevCreateOptions *options, Error **errp)
{
return qemu_rbd_do_create(options, NULL, NULL, errp);
}
static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
QemuOpts *opts,
Error **errp)
{
BlockdevCreateOptions *create_options;
BlockdevCreateOptionsRbd *rbd_opts;
BlockdevOptionsRbd *loc;
Error *local_err = NULL;
const char *keypairs, *password_secret;
QDict *options = NULL;
int ret = 0;
create_options = g_new0(BlockdevCreateOptions, 1);
create_options->driver = BLOCKDEV_DRIVER_RBD;
rbd_opts = &create_options->u.rbd;
rbd_opts->location = g_new0(BlockdevOptionsRbd, 1);
password_secret = qemu_opt_get(opts, "password-secret");
/* Read out options */
rbd_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
rbd_opts->cluster_size = qemu_opt_get_size_del(opts,
BLOCK_OPT_CLUSTER_SIZE, 0);
rbd_opts->has_cluster_size = (rbd_opts->cluster_size != 0);
options = qdict_new();
qemu_rbd_parse_filename(filename, options, &local_err);
if (local_err) {
ret = -EINVAL;
error_propagate(errp, local_err);
goto exit;
}
/*
* Caution: while qdict_get_try_str() is fine, getting non-string
* types would require more care. When @options come from -blockdev
* or blockdev_add, its members are typed according to the QAPI
* schema, but when they come from -drive, they're all QString.
*/
loc = rbd_opts->location;
loc->pool = g_strdup(qdict_get_try_str(options, "pool"));
loc->conf = g_strdup(qdict_get_try_str(options, "conf"));
loc->has_conf = !!loc->conf;
loc->user = g_strdup(qdict_get_try_str(options, "user"));
loc->has_user = !!loc->user;
loc->image = g_strdup(qdict_get_try_str(options, "image"));
keypairs = qdict_get_try_str(options, "=keyvalue-pairs");
ret = qemu_rbd_do_create(create_options, keypairs, password_secret, errp);
if (ret < 0) {
goto exit;
}
exit:
qobject_unref(options);
qapi_free_BlockdevCreateOptions(create_options);
return ret;
}
/*
* This aio completion is being called from rbd_finish_bh() and runs in qemu
* BH context.
*/
static void qemu_rbd_complete_aio(RADOSCB *rcb)
{
RBDAIOCB *acb = rcb->acb;
int64_t r;
r = rcb->ret;
if (acb->cmd != RBD_AIO_READ) {
if (r < 0) {
acb->ret = r;
acb->error = 1;
} else if (!acb->error) {
acb->ret = rcb->size;
}
} else {
if (r < 0) {
qemu_rbd_memset(rcb, 0);
acb->ret = r;
acb->error = 1;
} else if (r < rcb->size) {
qemu_rbd_memset(rcb, r);
if (!acb->error) {
acb->ret = rcb->size;
}
} else if (!acb->error) {
acb->ret = r;
}
}
g_free(rcb);
if (!LIBRBD_USE_IOVEC) {
if (acb->cmd == RBD_AIO_READ) {
qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
}
qemu_vfree(acb->bounce);
}
acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
qemu_aio_unref(acb);
}
static char *qemu_rbd_mon_host(BlockdevOptionsRbd *opts, Error **errp)
{
const char **vals;
const char *host, *port;
char *rados_str;
InetSocketAddressBaseList *p;
int i, cnt;
if (!opts->has_server) {
return NULL;
}
for (cnt = 0, p = opts->server; p; p = p->next) {
cnt++;
}
vals = g_new(const char *, cnt + 1);
for (i = 0, p = opts->server; p; p = p->next, i++) {
host = p->value->host;
port = p->value->port;
if (strchr(host, ':')) {
vals[i] = g_strdup_printf("[%s]:%s", host, port);
} else {
vals[i] = g_strdup_printf("%s:%s", host, port);
}
}
vals[i] = NULL;
rados_str = i ? g_strjoinv(";", (char **)vals) : NULL;
g_strfreev((char **)vals);
return rados_str;
}
static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
BlockdevOptionsRbd *opts, bool cache,
const char *keypairs, const char *secretid,
Error **errp)
{
char *mon_host = NULL;
Error *local_err = NULL;
int r;
if (secretid) {
if (opts->key_secret) {
error_setg(errp,
"Legacy 'password-secret' clashes with 'key-secret'");
return -EINVAL;
}
opts->key_secret = g_strdup(secretid);
opts->has_key_secret = true;
}
mon_host = qemu_rbd_mon_host(opts, &local_err);
if (local_err) {
error_propagate(errp, local_err);
r = -EINVAL;
goto failed_opts;
}
r = rados_create(cluster, opts->user);
if (r < 0) {
error_setg_errno(errp, -r, "error initializing");
goto failed_opts;
}
/* try default location when conf=NULL, but ignore failure */
r = rados_conf_read_file(*cluster, opts->conf);
if (opts->has_conf && r < 0) {
error_setg_errno(errp, -r, "error reading conf file %s", opts->conf);
goto failed_shutdown;
}
r = qemu_rbd_set_keypairs(*cluster, keypairs, errp);
if (r < 0) {
goto failed_shutdown;
}
if (mon_host) {
r = rados_conf_set(*cluster, "mon_host", mon_host);
if (r < 0) {
goto failed_shutdown;
}
}
r = qemu_rbd_set_auth(*cluster, opts, errp);
if (r < 0) {
goto failed_shutdown;
}
/*
* Fallback to more conservative semantics if setting cache
* options fails. Ignore errors from setting rbd_cache because the
* only possible error is that the option does not exist, and
* librbd defaults to no caching. If write through caching cannot
* be set up, fall back to no caching.
*/
if (cache) {
rados_conf_set(*cluster, "rbd_cache", "true");
} else {
rados_conf_set(*cluster, "rbd_cache", "false");
}
r = rados_connect(*cluster);
if (r < 0) {
error_setg_errno(errp, -r, "error connecting");
goto failed_shutdown;
}
r = rados_ioctx_create(*cluster, opts->pool, io_ctx);
if (r < 0) {
error_setg_errno(errp, -r, "error opening pool %s", opts->pool);
goto failed_shutdown;
}
return 0;
failed_shutdown:
rados_shutdown(*cluster);
failed_opts:
g_free(mon_host);
return r;
}
static int qemu_rbd_convert_options(QDict *options, BlockdevOptionsRbd **opts,
Error **errp)
{
Visitor *v;
Error *local_err = NULL;
/* Convert the remaining options into a QAPI object */
v = qobject_input_visitor_new_flat_confused(options, errp);
if (!v) {
return -EINVAL;
}
visit_type_BlockdevOptionsRbd(v, NULL, opts, &local_err);
visit_free(v);
if (local_err) {
error_propagate(errp, local_err);
return -EINVAL;
}
return 0;
}
static int qemu_rbd_attempt_legacy_options(QDict *options,
BlockdevOptionsRbd **opts,
char **keypairs)
{
char *filename;
int r;
filename = g_strdup(qdict_get_try_str(options, "filename"));
if (!filename) {
return -EINVAL;
}
qdict_del(options, "filename");
qemu_rbd_parse_filename(filename, options, NULL);
/* keypairs freed by caller */
*keypairs = g_strdup(qdict_get_try_str(options, "=keyvalue-pairs"));
if (*keypairs) {
qdict_del(options, "=keyvalue-pairs");
}
r = qemu_rbd_convert_options(options, opts, NULL);
g_free(filename);
return r;
}
static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVRBDState *s = bs->opaque;
BlockdevOptionsRbd *opts = NULL;
const QDictEntry *e;
Error *local_err = NULL;
char *keypairs, *secretid;
int r;
keypairs = g_strdup(qdict_get_try_str(options, "=keyvalue-pairs"));
if (keypairs) {
qdict_del(options, "=keyvalue-pairs");
}
secretid = g_strdup(qdict_get_try_str(options, "password-secret"));
if (secretid) {
qdict_del(options, "password-secret");
}
r = qemu_rbd_convert_options(options, &opts, &local_err);
if (local_err) {
/* If keypairs are present, that means some options are present in
* the modern option format. Don't attempt to parse legacy option
* formats, as we won't support mixed usage. */
if (keypairs) {
error_propagate(errp, local_err);
goto out;
}
/* If the initial attempt to convert and process the options failed,
* we may be attempting to open an image file that has the rbd options
* specified in the older format consisting of all key/value pairs
* encoded in the filename. Go ahead and attempt to parse the
* filename, and see if we can pull out the required options. */
r = qemu_rbd_attempt_legacy_options(options, &opts, &keypairs);
if (r < 0) {
/* Propagate the original error, not the legacy parsing fallback
* error, as the latter was just a best-effort attempt. */
error_propagate(errp, local_err);
goto out;
}
/* Take care whenever deciding to actually deprecate; once this ability
* is removed, we will not be able to open any images with legacy-styled
* backing image strings. */
warn_report("RBD options encoded in the filename as keyvalue pairs "
"is deprecated");
}
/* 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);
}
r = qemu_rbd_connect(&s->cluster, &s->io_ctx, opts,
!(flags & BDRV_O_NOCACHE), keypairs, secretid, errp);
if (r < 0) {
goto out;
}
s->snap = g_strdup(opts->snapshot);
s->image_name = g_strdup(opts->image);
/* rbd_open is always r/w */
r = rbd_open(s->io_ctx, s->image_name, &s->image, s->snap);
if (r < 0) {
error_setg_errno(errp, -r, "error reading header from %s",
s->image_name);
goto failed_open;
}
r = rbd_get_size(s->image, &s->image_size);
if (r < 0) {
error_setg_errno(errp, -r, "error getting image size from %s",
s->image_name);
rbd_close(s->image);
goto failed_open;
}
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
r = bdrv_apply_auto_read_only(bs, "rbd snapshots are read-only", errp);
if (r < 0) {
rbd_close(s->image);
goto failed_open;
}
}
r = 0;
goto out;
failed_open:
rados_ioctx_destroy(s->io_ctx);
g_free(s->snap);
g_free(s->image_name);
rados_shutdown(s->cluster);
out:
qapi_free_BlockdevOptionsRbd(opts);
g_free(keypairs);
g_free(secretid);
return r;
}
/* Since RBD is currently always opened R/W via the API,
* we just need to check if we are using a snapshot or not, in
* order to determine if we will allow it to be R/W */
static int qemu_rbd_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
BDRVRBDState *s = state->bs->opaque;
int ret = 0;
if (s->snap && state->flags & BDRV_O_RDWR) {
error_setg(errp,
"Cannot change node '%s' to r/w when using RBD snapshot",
bdrv_get_device_or_node_name(state->bs));
ret = -EINVAL;
}
return ret;
}
static void qemu_rbd_close(BlockDriverState *bs)
{
BDRVRBDState *s = bs->opaque;
rbd_close(s->image);
rados_ioctx_destroy(s->io_ctx);
g_free(s->snap);
g_free(s->image_name);
rados_shutdown(s->cluster);
}
/* Resize the RBD image and update the 'image_size' with the current size */
static int qemu_rbd_resize(BlockDriverState *bs, uint64_t size)
{
BDRVRBDState *s = bs->opaque;
int r;
r = rbd_resize(s->image, size);
if (r < 0) {
return r;
}
s->image_size = size;
return 0;
}
static const AIOCBInfo rbd_aiocb_info = {
.aiocb_size = sizeof(RBDAIOCB),
};
static void rbd_finish_bh(void *opaque)
{
RADOSCB *rcb = opaque;
qemu_rbd_complete_aio(rcb);
}
/*
* This is the callback function for rbd_aio_read and _write
*
* Note: this function is being called from a non qemu thread so
* we need to be careful about what we do here. Generally we only
* schedule a BH, and do the rest of the io completion handling
* from rbd_finish_bh() which runs in a qemu context.
*/
static void rbd_finish_aiocb(rbd_completion_t c, RADOSCB *rcb)
{
RBDAIOCB *acb = rcb->acb;
rcb->ret = rbd_aio_get_return_value(c);
rbd_aio_release(c);
replay_bh_schedule_oneshot_event(bdrv_get_aio_context(acb->common.bs),
rbd_finish_bh, rcb);
}
static int rbd_aio_discard_wrapper(rbd_image_t image,
uint64_t off,
uint64_t len,
rbd_completion_t comp)
{
#ifdef LIBRBD_SUPPORTS_DISCARD
return rbd_aio_discard(image, off, len, comp);
#else
return -ENOTSUP;
#endif
}
static int rbd_aio_flush_wrapper(rbd_image_t image,
rbd_completion_t comp)
{
#ifdef LIBRBD_SUPPORTS_AIO_FLUSH
return rbd_aio_flush(image, comp);
#else
return -ENOTSUP;
#endif
}
static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
int64_t off,
QEMUIOVector *qiov,
int64_t size,
BlockCompletionFunc *cb,
void *opaque,
RBDAIOCmd cmd)
{
RBDAIOCB *acb;
RADOSCB *rcb = NULL;
rbd_completion_t c;
int r;
BDRVRBDState *s = bs->opaque;
acb = qemu_aio_get(&rbd_aiocb_info, bs, cb, opaque);
acb->cmd = cmd;
acb->qiov = qiov;
assert(!qiov || qiov->size == size);
rcb = g_new(RADOSCB, 1);
if (!LIBRBD_USE_IOVEC) {
if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
acb->bounce = NULL;
} else {
acb->bounce = qemu_try_blockalign(bs, qiov->size);
if (acb->bounce == NULL) {
goto failed;
}
}
if (cmd == RBD_AIO_WRITE) {
qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
}
rcb->buf = acb->bounce;
}
acb->ret = 0;
acb->error = 0;
acb->s = s;
rcb->acb = acb;
rcb->s = acb->s;
rcb->size = size;
r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c);
if (r < 0) {
goto failed;
}
switch (cmd) {
case RBD_AIO_WRITE: {
/*
* RBD APIs don't allow us to write more than actual size, so in order
* to support growing images, we resize the image before write
* operations that exceed the current size.
*/
if (off + size > s->image_size) {
r = qemu_rbd_resize(bs, off + size);
if (r < 0) {
goto failed_completion;
}
}
#ifdef LIBRBD_SUPPORTS_IOVEC
r = rbd_aio_writev(s->image, qiov->iov, qiov->niov, off, c);
#else
r = rbd_aio_write(s->image, off, size, rcb->buf, c);
#endif
break;
}
case RBD_AIO_READ:
#ifdef LIBRBD_SUPPORTS_IOVEC
r = rbd_aio_readv(s->image, qiov->iov, qiov->niov, off, c);
#else
r = rbd_aio_read(s->image, off, size, rcb->buf, c);
#endif
break;
case RBD_AIO_DISCARD:
r = rbd_aio_discard_wrapper(s->image, off, size, c);
break;
case RBD_AIO_FLUSH:
r = rbd_aio_flush_wrapper(s->image, c);
break;
default:
r = -EINVAL;
}
if (r < 0) {
goto failed_completion;
}
return &acb->common;
failed_completion:
rbd_aio_release(c);
failed:
g_free(rcb);
if (!LIBRBD_USE_IOVEC) {
qemu_vfree(acb->bounce);
}
qemu_aio_unref(acb);
return NULL;
}
static BlockAIOCB *qemu_rbd_aio_preadv(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags,
BlockCompletionFunc *cb,
void *opaque)
{
return rbd_start_aio(bs, offset, qiov, bytes, cb, opaque,
RBD_AIO_READ);
}
static BlockAIOCB *qemu_rbd_aio_pwritev(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags,
BlockCompletionFunc *cb,
void *opaque)
{
return rbd_start_aio(bs, offset, qiov, bytes, cb, opaque,
RBD_AIO_WRITE);
}
#ifdef LIBRBD_SUPPORTS_AIO_FLUSH
static BlockAIOCB *qemu_rbd_aio_flush(BlockDriverState *bs,
BlockCompletionFunc *cb,
void *opaque)
{
return rbd_start_aio(bs, 0, NULL, 0, cb, opaque, RBD_AIO_FLUSH);
}
#else
static int qemu_rbd_co_flush(BlockDriverState *bs)
{
#if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 1)
/* rbd_flush added in 0.1.1 */
BDRVRBDState *s = bs->opaque;
return rbd_flush(s->image);
#else
return 0;
#endif
}
#endif
static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVRBDState *s = bs->opaque;
rbd_image_info_t info;
int r;
r = rbd_stat(s->image, &info, sizeof(info));
if (r < 0) {
return r;
}
bdi->cluster_size = info.obj_size;
return 0;
}
static int64_t qemu_rbd_getlength(BlockDriverState *bs)
{
BDRVRBDState *s = bs->opaque;
rbd_image_info_t info;
int r;
r = rbd_stat(s->image, &info, sizeof(info));
if (r < 0) {
return r;
}
return info.size;
}
static int coroutine_fn qemu_rbd_co_truncate(BlockDriverState *bs,
int64_t offset,
bool exact,
PreallocMode prealloc,
Error **errp)
{
int r;
if (prealloc != PREALLOC_MODE_OFF) {
error_setg(errp, "Unsupported preallocation mode '%s'",
PreallocMode_str(prealloc));
return -ENOTSUP;
}
r = qemu_rbd_resize(bs, offset);
if (r < 0) {
error_setg_errno(errp, -r, "Failed to resize file");
return r;
}
return 0;
}
static int qemu_rbd_snap_create(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info)
{
BDRVRBDState *s = bs->opaque;
int r;
if (sn_info->name[0] == '\0') {
return -EINVAL; /* we need a name for rbd snapshots */
}
/*
* rbd snapshots are using the name as the user controlled unique identifier
* we can't use the rbd snapid for that purpose, as it can't be set
*/
if (sn_info->id_str[0] != '\0' &&
strcmp(sn_info->id_str, sn_info->name) != 0) {
return -EINVAL;
}
if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) {
return -ERANGE;
}
r = rbd_snap_create(s->image, sn_info->name);
if (r < 0) {
error_report("failed to create snap: %s", strerror(-r));
return r;
}
return 0;
}
static int qemu_rbd_snap_remove(BlockDriverState *bs,
const char *snapshot_id,
const char *snapshot_name,
Error **errp)
{
BDRVRBDState *s = bs->opaque;
int r;
if (!snapshot_name) {
error_setg(errp, "rbd need a valid snapshot name");
return -EINVAL;
}
/* If snapshot_id is specified, it must be equal to name, see
qemu_rbd_snap_list() */
if (snapshot_id && strcmp(snapshot_id, snapshot_name)) {
error_setg(errp,
"rbd do not support snapshot id, it should be NULL or "
"equal to snapshot name");
return -EINVAL;
}
r = rbd_snap_remove(s->image, snapshot_name);
if (r < 0) {
error_setg_errno(errp, -r, "Failed to remove the snapshot");
}
return r;
}
static int qemu_rbd_snap_rollback(BlockDriverState *bs,
const char *snapshot_name)
{
BDRVRBDState *s = bs->opaque;
return rbd_snap_rollback(s->image, snapshot_name);
}
static int qemu_rbd_snap_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_tab)
{
BDRVRBDState *s = bs->opaque;
QEMUSnapshotInfo *sn_info, *sn_tab = NULL;
int i, snap_count;
rbd_snap_info_t *snaps;
int max_snaps = RBD_MAX_SNAPS;
do {
snaps = g_new(rbd_snap_info_t, max_snaps);
snap_count = rbd_snap_list(s->image, snaps, &max_snaps);
if (snap_count <= 0) {
g_free(snaps);
}
} while (snap_count == -ERANGE);
if (snap_count <= 0) {
goto done;
}
sn_tab = g_new0(QEMUSnapshotInfo, snap_count);
for (i = 0; i < snap_count; i++) {
const char *snap_name = snaps[i].name;
sn_info = sn_tab + i;
pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), snap_name);
pstrcpy(sn_info->name, sizeof(sn_info->name), snap_name);
sn_info->vm_state_size = snaps[i].size;
sn_info->date_sec = 0;
sn_info->date_nsec = 0;
sn_info->vm_clock_nsec = 0;
}
rbd_snap_list_end(snaps);
g_free(snaps);
done:
*psn_tab = sn_tab;
return snap_count;
}
#ifdef LIBRBD_SUPPORTS_DISCARD
static BlockAIOCB *qemu_rbd_aio_pdiscard(BlockDriverState *bs,
int64_t offset,
int bytes,
BlockCompletionFunc *cb,
void *opaque)
{
return rbd_start_aio(bs, offset, NULL, bytes, cb, opaque,
RBD_AIO_DISCARD);
}
#endif
#ifdef LIBRBD_SUPPORTS_INVALIDATE
static void coroutine_fn qemu_rbd_co_invalidate_cache(BlockDriverState *bs,
Error **errp)
{
BDRVRBDState *s = bs->opaque;
int r = rbd_invalidate_cache(s->image);
if (r < 0) {
error_setg_errno(errp, -r, "Failed to invalidate the cache");
}
}
#endif
static QemuOptsList qemu_rbd_create_opts = {
.name = "rbd-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(qemu_rbd_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
{
.name = BLOCK_OPT_CLUSTER_SIZE,
.type = QEMU_OPT_SIZE,
.help = "RBD object size"
},
{
.name = "password-secret",
.type = QEMU_OPT_STRING,
.help = "ID of secret providing the password",
},
{ /* end of list */ }
}
};
static const char *const qemu_rbd_strong_runtime_opts[] = {
"pool",
"image",
"conf",
"snapshot",
"user",
"server.",
"password-secret",
NULL
};
static BlockDriver bdrv_rbd = {
.format_name = "rbd",
.instance_size = sizeof(BDRVRBDState),
.bdrv_parse_filename = qemu_rbd_parse_filename,
.bdrv_refresh_limits = qemu_rbd_refresh_limits,
.bdrv_file_open = qemu_rbd_open,
.bdrv_close = qemu_rbd_close,
.bdrv_reopen_prepare = qemu_rbd_reopen_prepare,
.bdrv_co_create = qemu_rbd_co_create,
.bdrv_co_create_opts = qemu_rbd_co_create_opts,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_has_zero_init_truncate = bdrv_has_zero_init_1,
.bdrv_get_info = qemu_rbd_getinfo,
.create_opts = &qemu_rbd_create_opts,
.bdrv_getlength = qemu_rbd_getlength,
.bdrv_co_truncate = qemu_rbd_co_truncate,
.protocol_name = "rbd",
.bdrv_aio_preadv = qemu_rbd_aio_preadv,
.bdrv_aio_pwritev = qemu_rbd_aio_pwritev,
#ifdef LIBRBD_SUPPORTS_AIO_FLUSH
.bdrv_aio_flush = qemu_rbd_aio_flush,
#else
.bdrv_co_flush_to_disk = qemu_rbd_co_flush,
#endif
#ifdef LIBRBD_SUPPORTS_DISCARD
.bdrv_aio_pdiscard = qemu_rbd_aio_pdiscard,
#endif
.bdrv_snapshot_create = qemu_rbd_snap_create,
.bdrv_snapshot_delete = qemu_rbd_snap_remove,
.bdrv_snapshot_list = qemu_rbd_snap_list,
.bdrv_snapshot_goto = qemu_rbd_snap_rollback,
#ifdef LIBRBD_SUPPORTS_INVALIDATE
.bdrv_co_invalidate_cache = qemu_rbd_co_invalidate_cache,
#endif
.strong_runtime_opts = qemu_rbd_strong_runtime_opts,
};
static void bdrv_rbd_init(void)
{
bdrv_register(&bdrv_rbd);
}
block_init(bdrv_rbd_init);
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