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qemu/block/rbd.c
Peter Lieven c56ac27d2a block/rbd: add write zeroes support 
This patch wittingly sets BDRV_REQ_NO_FALLBACK and silently ignores
BDRV_REQ_MAY_UNMAP for older librbd versions.

The rationale for this is as follows (citing Ilya Dryomov current RBD
maintainer):

---8<---
a) remove the BDRV_REQ_MAY_UNMAP check in qemu_rbd_co_pwrite_zeroes()
   and as a consequence always unmap if librbd is too old

   It's not clear what qemu's expectation is but in general Write
   Zeroes is allowed to unmap.  The only guarantee is that subsequent
   reads return zeroes, everything else is a hint.  This is how it is
   specified in the kernel and in the NVMe spec.

   In particular, block/nvme.c implements it as follows:

   if (flags & BDRV_REQ_MAY_UNMAP) {
       cdw12 |= (1 << 25);
   }

   This sets the Deallocate bit.  But if it's not set, the device may
   still deallocate:

   """
   If the Deallocate bit (CDW12.DEAC) is set to '1' in a Write Zeroes
   command, and the namespace supports clearing all bytes to 0h in the
   values read (e.g., bits 2:0 in the DLFEAT field are set to 001b)
   from a deallocated logical block and its metadata (excluding
   protection information), then for each specified logical block, the
   controller:
   - should deallocate that logical block;

   ...

   If the Deallocate bit is cleared to '0' in a Write Zeroes command,
   and the namespace supports clearing all bytes to 0h in the values
   read (e.g., bits 2:0 in the DLFEAT field are set to 001b) from
   a deallocated logical block and its metadata (excluding protection
   information), then, for each specified logical block, the
   controller:
   - may deallocate that logical block;
   """

   https://nvmexpress.org/wp-content/uploads/NVM-Express-NVM-Command-Set-Specification-2021.06.02-Ratified-1.pdf

b) set BDRV_REQ_NO_FALLBACK in supported_zero_flags

   Again, it's not clear what qemu expects here, but without it we end
   up in a ridiculous situation where specifying the "don't allow slow
   fallback" switch immediately fails all efficient zeroing requests on
   a device where Write Zeroes is always efficient:

   $ qemu-io -c 'help write' | grep -- '-[zun]'
    -n, -- with -z, don't allow slow fallback
    -u, -- with -z, allow unmapping
    -z, -- write zeroes using blk_co_pwrite_zeroes

   $ qemu-io -f rbd -c 'write -z -u -n 0 1M' rbd:foo/bar
   write failed: Operation not supported
--->8---

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Message-Id: <20210702172356.11574-6-idryomov@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09 12:26:05 +02:00

1522 lines
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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 "\".
*/
#define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)
#define RBD_MAX_SNAPS 100
#define RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN 8
static const char rbd_luks_header_verification[
RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN] = {
'L', 'U', 'K', 'S', 0xBA, 0xBE, 0, 1
};
static const char rbd_luks2_header_verification[
RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN] = {
'L', 'U', 'K', 'S', 0xBA, 0xBE, 0, 2
};
typedef enum {
RBD_AIO_READ,
RBD_AIO_WRITE,
RBD_AIO_DISCARD,
RBD_AIO_FLUSH,
RBD_AIO_WRITE_ZEROES
} RBDAIOCmd;
typedef struct BDRVRBDState {
rados_t cluster;
rados_ioctx_t io_ctx;
rbd_image_t image;
char *image_name;
char *snap;
char *namespace;
uint64_t image_size;
uint64_t object_size;
} BDRVRBDState;
typedef struct RBDTask {
BlockDriverState *bs;
Coroutine *co;
bool complete;
int64_t ret;
} RBDTask;
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_strchr(char *src, char delim)
{
char *p;
for (p = src; *p; ++p) {
if (*p == delim) {
return p;
}
if (*p == '\\' && p[1] != '\0') {
++p;
}
}
return NULL;
}
static char *qemu_rbd_next_tok(char *src, char delim, char **p)
{
char *end;
*p = NULL;
end = qemu_rbd_strchr(src, delim);
if (end) {
*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, *image_name;
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 (qemu_rbd_strchr(p, '@')) {
image_name = qemu_rbd_next_tok(p, '@', &p);
found_str = qemu_rbd_next_tok(p, ':', &p);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "snapshot", found_str);
} else {
image_name = qemu_rbd_next_tok(p, ':', &p);
}
/* Check for namespace in the image_name */
if (qemu_rbd_strchr(image_name, '/')) {
found_str = qemu_rbd_next_tok(image_name, '/', &image_name);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "namespace", found_str);
} else {
qdict_put_str(options, "namespace", "");
}
qemu_rbd_unescape(image_name);
qdict_put_str(options, "image", image_name);
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",
qstring_from_gstring(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;
}
#ifdef LIBRBD_SUPPORTS_ENCRYPTION
static int qemu_rbd_convert_luks_options(
RbdEncryptionOptionsLUKSBase *luks_opts,
char **passphrase,
size_t *passphrase_len,
Error **errp)
{
return qcrypto_secret_lookup(luks_opts->key_secret, (uint8_t **)passphrase,
passphrase_len, errp);
}
static int qemu_rbd_convert_luks_create_options(
RbdEncryptionCreateOptionsLUKSBase *luks_opts,
rbd_encryption_algorithm_t *alg,
char **passphrase,
size_t *passphrase_len,
Error **errp)
{
int r = 0;
r = qemu_rbd_convert_luks_options(
qapi_RbdEncryptionCreateOptionsLUKSBase_base(luks_opts),
passphrase, passphrase_len, errp);
if (r < 0) {
return r;
}
if (luks_opts->has_cipher_alg) {
switch (luks_opts->cipher_alg) {
case QCRYPTO_CIPHER_ALG_AES_128: {
*alg = RBD_ENCRYPTION_ALGORITHM_AES128;
break;
}
case QCRYPTO_CIPHER_ALG_AES_256: {
*alg = RBD_ENCRYPTION_ALGORITHM_AES256;
break;
}
default: {
r = -ENOTSUP;
error_setg_errno(errp, -r, "unknown encryption algorithm: %u",
luks_opts->cipher_alg);
return r;
}
}
} else {
/* default alg */
*alg = RBD_ENCRYPTION_ALGORITHM_AES256;
}
return 0;
}
static int qemu_rbd_encryption_format(rbd_image_t image,
RbdEncryptionCreateOptions *encrypt,
Error **errp)
{
int r = 0;
g_autofree char *passphrase = NULL;
size_t passphrase_len;
rbd_encryption_format_t format;
rbd_encryption_options_t opts;
rbd_encryption_luks1_format_options_t luks_opts;
rbd_encryption_luks2_format_options_t luks2_opts;
size_t opts_size;
uint64_t raw_size, effective_size;
r = rbd_get_size(image, &raw_size);
if (r < 0) {
error_setg_errno(errp, -r, "cannot get raw image size");
return r;
}
switch (encrypt->format) {
case RBD_IMAGE_ENCRYPTION_FORMAT_LUKS: {
memset(&luks_opts, 0, sizeof(luks_opts));
format = RBD_ENCRYPTION_FORMAT_LUKS1;
opts = &luks_opts;
opts_size = sizeof(luks_opts);
r = qemu_rbd_convert_luks_create_options(
qapi_RbdEncryptionCreateOptionsLUKS_base(&encrypt->u.luks),
&luks_opts.alg, &passphrase, &passphrase_len, errp);
if (r < 0) {
return r;
}
luks_opts.passphrase = passphrase;
luks_opts.passphrase_size = passphrase_len;
break;
}
case RBD_IMAGE_ENCRYPTION_FORMAT_LUKS2: {
memset(&luks2_opts, 0, sizeof(luks2_opts));
format = RBD_ENCRYPTION_FORMAT_LUKS2;
opts = &luks2_opts;
opts_size = sizeof(luks2_opts);
r = qemu_rbd_convert_luks_create_options(
qapi_RbdEncryptionCreateOptionsLUKS2_base(
&encrypt->u.luks2),
&luks2_opts.alg, &passphrase, &passphrase_len, errp);
if (r < 0) {
return r;
}
luks2_opts.passphrase = passphrase;
luks2_opts.passphrase_size = passphrase_len;
break;
}
default: {
r = -ENOTSUP;
error_setg_errno(
errp, -r, "unknown image encryption format: %u",
encrypt->format);
return r;
}
}
r = rbd_encryption_format(image, format, opts, opts_size);
if (r < 0) {
error_setg_errno(errp, -r, "encryption format fail");
return r;
}
r = rbd_get_size(image, &effective_size);
if (r < 0) {
error_setg_errno(errp, -r, "cannot get effective image size");
return r;
}
r = rbd_resize(image, raw_size + (raw_size - effective_size));
if (r < 0) {
error_setg_errno(errp, -r, "cannot resize image after format");
return r;
}
return 0;
}
static int qemu_rbd_encryption_load(rbd_image_t image,
RbdEncryptionOptions *encrypt,
Error **errp)
{
int r = 0;
g_autofree char *passphrase = NULL;
size_t passphrase_len;
rbd_encryption_luks1_format_options_t luks_opts;
rbd_encryption_luks2_format_options_t luks2_opts;
rbd_encryption_format_t format;
rbd_encryption_options_t opts;
size_t opts_size;
switch (encrypt->format) {
case RBD_IMAGE_ENCRYPTION_FORMAT_LUKS: {
memset(&luks_opts, 0, sizeof(luks_opts));
format = RBD_ENCRYPTION_FORMAT_LUKS1;
opts = &luks_opts;
opts_size = sizeof(luks_opts);
r = qemu_rbd_convert_luks_options(
qapi_RbdEncryptionOptionsLUKS_base(&encrypt->u.luks),
&passphrase, &passphrase_len, errp);
if (r < 0) {
return r;
}
luks_opts.passphrase = passphrase;
luks_opts.passphrase_size = passphrase_len;
break;
}
case RBD_IMAGE_ENCRYPTION_FORMAT_LUKS2: {
memset(&luks2_opts, 0, sizeof(luks2_opts));
format = RBD_ENCRYPTION_FORMAT_LUKS2;
opts = &luks2_opts;
opts_size = sizeof(luks2_opts);
r = qemu_rbd_convert_luks_options(
qapi_RbdEncryptionOptionsLUKS2_base(&encrypt->u.luks2),
&passphrase, &passphrase_len, errp);
if (r < 0) {
return r;
}
luks2_opts.passphrase = passphrase;
luks2_opts.passphrase_size = passphrase_len;
break;
}
default: {
r = -ENOTSUP;
error_setg_errno(
errp, -r, "unknown image encryption format: %u",
encrypt->format);
return r;
}
}
r = rbd_encryption_load(image, format, opts, opts_size);
if (r < 0) {
error_setg_errno(errp, -r, "encryption load fail");
return r;
}
return 0;
}
#endif
/* 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;
}
#ifndef LIBRBD_SUPPORTS_ENCRYPTION
if (opts->has_encrypt) {
error_setg(errp, "RBD library does not support image encryption");
return -ENOTSUP;
}
#endif
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;
}
#ifdef LIBRBD_SUPPORTS_ENCRYPTION
if (opts->has_encrypt) {
rbd_image_t image;
ret = rbd_open(io_ctx, opts->location->image, &image, NULL);
if (ret < 0) {
error_setg_errno(errp, -ret,
"error opening image '%s' for encryption format",
opts->location->image);
goto out;
}
ret = qemu_rbd_encryption_format(image, opts->encrypt, errp);
rbd_close(image);
if (ret < 0) {
/* encryption format fail, try removing the image */
rbd_remove(io_ctx, opts->location->image);
goto out;
}
}
#endif
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 qemu_rbd_extract_encryption_create_options(
QemuOpts *opts,
RbdEncryptionCreateOptions **spec,
Error **errp)
{
QDict *opts_qdict;
QDict *encrypt_qdict;
Visitor *v;
int ret = 0;
opts_qdict = qemu_opts_to_qdict(opts, NULL);
qdict_extract_subqdict(opts_qdict, &encrypt_qdict, "encrypt.");
qobject_unref(opts_qdict);
if (!qdict_size(encrypt_qdict)) {
*spec = NULL;
goto exit;
}
/* Convert options into a QAPI object */
v = qobject_input_visitor_new_flat_confused(encrypt_qdict, errp);
if (!v) {
ret = -EINVAL;
goto exit;
}
visit_type_RbdEncryptionCreateOptions(v, NULL, spec, errp);
visit_free(v);
if (!*spec) {
ret = -EINVAL;
goto exit;
}
exit:
qobject_unref(encrypt_qdict);
return ret;
}
static int coroutine_fn qemu_rbd_co_create_opts(BlockDriver *drv,
const char *filename,
QemuOpts *opts,
Error **errp)
{
BlockdevCreateOptions *create_options;
BlockdevCreateOptionsRbd *rbd_opts;
BlockdevOptionsRbd *loc;
RbdEncryptionCreateOptions *encrypt = NULL;
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;
}
ret = qemu_rbd_extract_encryption_create_options(opts, &encrypt, errp);
if (ret < 0) {
goto exit;
}
rbd_opts->encrypt = encrypt;
rbd_opts->has_encrypt = !!encrypt;
/*
* 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->q_namespace = g_strdup(qdict_get_try_str(options, "namespace"));
loc->has_q_namespace = !!loc->q_namespace;
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;
}
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 out;
}
r = rados_create(cluster, opts->user);
if (r < 0) {
error_setg_errno(errp, -r, "error initializing");
goto out;
}
/* 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;
}
/*
* Set the namespace after opening the io context on the pool,
* if nspace == NULL or if nspace == "", it is just as we did nothing
*/
rados_ioctx_set_namespace(*io_ctx, opts->q_namespace);
r = 0;
goto out;
failed_shutdown:
rados_shutdown(*cluster);
out:
g_free(mon_host);
return r;
}
static int qemu_rbd_convert_options(QDict *options, BlockdevOptionsRbd **opts,
Error **errp)
{
Visitor *v;
/* 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, errp);
visit_free(v);
if (!opts) {
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;
rbd_image_info_t info;
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;
}
if (opts->has_encrypt) {
#ifdef LIBRBD_SUPPORTS_ENCRYPTION
r = qemu_rbd_encryption_load(s->image, opts->encrypt, errp);
if (r < 0) {
goto failed_post_open;
}
#else
r = -ENOTSUP;
error_setg(errp, "RBD library does not support image encryption");
goto failed_post_open;
#endif
}
r = rbd_stat(s->image, &info, sizeof(info));
if (r < 0) {
error_setg_errno(errp, -r, "error getting image info from %s",
s->image_name);
goto failed_post_open;
}
s->image_size = info.size;
s->object_size = info.obj_size;
/* 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) {
goto failed_post_open;
}
}
#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK;
#endif
/* When extending regular files, we get zeros from the OS */
bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
r = 0;
goto out;
failed_post_open:
rbd_close(s->image);
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 void qemu_rbd_finish_bh(void *opaque)
{
RBDTask *task = opaque;
task->complete = 1;
aio_co_wake(task->co);
}
/*
* This is the completion callback function for all rbd aio calls
* started from qemu_rbd_start_co().
*
* 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 qemu_rbd_finish_bh() which runs in a qemu context.
*/
static void qemu_rbd_completion_cb(rbd_completion_t c, RBDTask *task)
{
task->ret = rbd_aio_get_return_value(c);
rbd_aio_release(c);
aio_bh_schedule_oneshot(bdrv_get_aio_context(task->bs),
qemu_rbd_finish_bh, task);
}
static int coroutine_fn qemu_rbd_start_co(BlockDriverState *bs,
uint64_t offset,
uint64_t bytes,
QEMUIOVector *qiov,
int flags,
RBDAIOCmd cmd)
{
BDRVRBDState *s = bs->opaque;
RBDTask task = { .bs = bs, .co = qemu_coroutine_self() };
rbd_completion_t c;
int r;
assert(!qiov || qiov->size == bytes);
r = rbd_aio_create_completion(&task,
(rbd_callback_t) qemu_rbd_completion_cb, &c);
if (r < 0) {
return r;
}
switch (cmd) {
case RBD_AIO_READ:
r = rbd_aio_readv(s->image, qiov->iov, qiov->niov, offset, c);
break;
case RBD_AIO_WRITE:
r = rbd_aio_writev(s->image, qiov->iov, qiov->niov, offset, c);
break;
case RBD_AIO_DISCARD:
r = rbd_aio_discard(s->image, offset, bytes, c);
break;
case RBD_AIO_FLUSH:
r = rbd_aio_flush(s->image, c);
break;
#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
case RBD_AIO_WRITE_ZEROES: {
int zero_flags = 0;
#ifdef RBD_WRITE_ZEROES_FLAG_THICK_PROVISION
if (!(flags & BDRV_REQ_MAY_UNMAP)) {
zero_flags = RBD_WRITE_ZEROES_FLAG_THICK_PROVISION;
}
#endif
r = rbd_aio_write_zeroes(s->image, offset, bytes, c, zero_flags, 0);
break;
}
#endif
default:
r = -EINVAL;
}
if (r < 0) {
error_report("rbd request failed early: cmd %d offset %" PRIu64
" bytes %" PRIu64 " flags %d r %d (%s)", cmd, offset,
bytes, flags, r, strerror(-r));
rbd_aio_release(c);
return r;
}
while (!task.complete) {
qemu_coroutine_yield();
}
if (task.ret < 0) {
error_report("rbd request failed: cmd %d offset %" PRIu64 " bytes %"
PRIu64 " flags %d task.ret %" PRIi64 " (%s)", cmd, offset,
bytes, flags, task.ret, strerror(-task.ret));
return task.ret;
}
/* zero pad short reads */
if (cmd == RBD_AIO_READ && task.ret < qiov->size) {
qemu_iovec_memset(qiov, task.ret, 0, qiov->size - task.ret);
}
return 0;
}
static int
coroutine_fn qemu_rbd_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov,
int flags)
{
return qemu_rbd_start_co(bs, offset, bytes, qiov, flags, RBD_AIO_READ);
}
static int
coroutine_fn qemu_rbd_co_pwritev(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov,
int flags)
{
BDRVRBDState *s = bs->opaque;
/*
* 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 (offset + bytes > s->image_size) {
int r = qemu_rbd_resize(bs, offset + bytes);
if (r < 0) {
return r;
}
}
return qemu_rbd_start_co(bs, offset, bytes, qiov, flags, RBD_AIO_WRITE);
}
static int coroutine_fn qemu_rbd_co_flush(BlockDriverState *bs)
{
return qemu_rbd_start_co(bs, 0, 0, NULL, 0, RBD_AIO_FLUSH);
}
static int coroutine_fn qemu_rbd_co_pdiscard(BlockDriverState *bs,
int64_t offset, int count)
{
return qemu_rbd_start_co(bs, offset, count, NULL, 0, RBD_AIO_DISCARD);
}
#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
static int
coroutine_fn qemu_rbd_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
int count, BdrvRequestFlags flags)
{
return qemu_rbd_start_co(bs, offset, count, NULL, flags,
RBD_AIO_WRITE_ZEROES);
}
#endif
static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVRBDState *s = bs->opaque;
bdi->cluster_size = s->object_size;
return 0;
}
static ImageInfoSpecific *qemu_rbd_get_specific_info(BlockDriverState *bs,
Error **errp)
{
BDRVRBDState *s = bs->opaque;
ImageInfoSpecific *spec_info;
char buf[RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN] = {0};
int r;
if (s->image_size >= RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN) {
r = rbd_read(s->image, 0,
RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN, buf);
if (r < 0) {
error_setg_errno(errp, -r, "cannot read image start for probe");
return NULL;
}
}
spec_info = g_new(ImageInfoSpecific, 1);
*spec_info = (ImageInfoSpecific){
.type = IMAGE_INFO_SPECIFIC_KIND_RBD,
.u.rbd.data = g_new0(ImageInfoSpecificRbd, 1),
};
if (memcmp(buf, rbd_luks_header_verification,
RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN) == 0) {
spec_info->u.rbd.data->encryption_format =
RBD_IMAGE_ENCRYPTION_FORMAT_LUKS;
spec_info->u.rbd.data->has_encryption_format = true;
} else if (memcmp(buf, rbd_luks2_header_verification,
RBD_ENCRYPTION_LUKS_HEADER_VERIFICATION_LEN) == 0) {
spec_info->u.rbd.data->encryption_format =
RBD_IMAGE_ENCRYPTION_FORMAT_LUKS2;
spec_info->u.rbd.data->has_encryption_format = true;
} else {
spec_info->u.rbd.data->has_encryption_format = false;
}
return spec_info;
}
static int64_t qemu_rbd_getlength(BlockDriverState *bs)
{
BDRVRBDState *s = bs->opaque;
int r;
r = rbd_get_size(s->image, &s->image_size);
if (r < 0) {
return r;
}
return s->image_size;
}
static int coroutine_fn qemu_rbd_co_truncate(BlockDriverState *bs,
int64_t offset,
bool exact,
PreallocMode prealloc,
BdrvRequestFlags flags,
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;
}
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");
}
}
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",
},
{
.name = "encrypt.format",
.type = QEMU_OPT_STRING,
.help = "Encrypt the image, format choices: 'luks', 'luks2'",
},
{
.name = "encrypt.cipher-alg",
.type = QEMU_OPT_STRING,
.help = "Name of encryption cipher algorithm"
" (allowed values: aes-128, aes-256)",
},
{
.name = "encrypt.key-secret",
.type = QEMU_OPT_STRING,
.help = "ID of secret providing LUKS passphrase",
},
{ /* end of list */ }
}
};
static const char *const qemu_rbd_strong_runtime_opts[] = {
"pool",
"namespace",
"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_get_info = qemu_rbd_getinfo,
.bdrv_get_specific_info = qemu_rbd_get_specific_info,
.create_opts = &qemu_rbd_create_opts,
.bdrv_getlength = qemu_rbd_getlength,
.bdrv_co_truncate = qemu_rbd_co_truncate,
.protocol_name = "rbd",
.bdrv_co_preadv = qemu_rbd_co_preadv,
.bdrv_co_pwritev = qemu_rbd_co_pwritev,
.bdrv_co_flush_to_disk = qemu_rbd_co_flush,
.bdrv_co_pdiscard = qemu_rbd_co_pdiscard,
#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
.bdrv_co_pwrite_zeroes = qemu_rbd_co_pwrite_zeroes,
#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,
.bdrv_co_invalidate_cache = qemu_rbd_co_invalidate_cache,
.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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