/* * GlusterFS backend for QEMU * * Copyright (C) 2012 Bharata B Rao * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include "qemu/osdep.h" #include "qemu/units.h" #include #include "block/block_int.h" #include "block/qdict.h" #include "qapi/error.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qerror.h" #include "qemu/uri.h" #include "qemu/error-report.h" #include "qemu/module.h" #include "qemu/option.h" #include "qemu/cutils.h" #ifdef CONFIG_GLUSTERFS_FTRUNCATE_HAS_STAT # define glfs_ftruncate(fd, offset) glfs_ftruncate(fd, offset, NULL, NULL) #endif #define GLUSTER_OPT_FILENAME "filename" #define GLUSTER_OPT_VOLUME "volume" #define GLUSTER_OPT_PATH "path" #define GLUSTER_OPT_TYPE "type" #define GLUSTER_OPT_SERVER_PATTERN "server." #define GLUSTER_OPT_HOST "host" #define GLUSTER_OPT_PORT "port" #define GLUSTER_OPT_TO "to" #define GLUSTER_OPT_IPV4 "ipv4" #define GLUSTER_OPT_IPV6 "ipv6" #define GLUSTER_OPT_SOCKET "socket" #define GLUSTER_OPT_DEBUG "debug" #define GLUSTER_DEFAULT_PORT 24007 #define GLUSTER_DEBUG_DEFAULT 4 #define GLUSTER_DEBUG_MAX 9 #define GLUSTER_OPT_LOGFILE "logfile" #define GLUSTER_LOGFILE_DEFAULT "-" /* handled in libgfapi as /dev/stderr */ /* * Several versions of GlusterFS (3.12? -> 6.0.1) fail when the transfer size * is greater or equal to 1024 MiB, so we are limiting the transfer size to 512 * MiB to avoid this rare issue. */ #define GLUSTER_MAX_TRANSFER (512 * MiB) #define GERR_INDEX_HINT "hint: check in 'server' array index '%d'\n" typedef struct GlusterAIOCB { int64_t size; int ret; Coroutine *coroutine; AioContext *aio_context; } GlusterAIOCB; typedef struct BDRVGlusterState { struct glfs *glfs; struct glfs_fd *fd; char *logfile; bool supports_seek_data; int debug; } BDRVGlusterState; typedef struct BDRVGlusterReopenState { struct glfs *glfs; struct glfs_fd *fd; } BDRVGlusterReopenState; typedef struct GlfsPreopened { char *volume; glfs_t *fs; int ref; } GlfsPreopened; typedef struct ListElement { QLIST_ENTRY(ListElement) list; GlfsPreopened saved; } ListElement; static QLIST_HEAD(, ListElement) glfs_list; static QemuOptsList qemu_gluster_create_opts = { .name = "qemu-gluster-create-opts", .head = QTAILQ_HEAD_INITIALIZER(qemu_gluster_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, { .name = BLOCK_OPT_PREALLOC, .type = QEMU_OPT_STRING, .help = "Preallocation mode (allowed values: off" #ifdef CONFIG_GLUSTERFS_FALLOCATE ", falloc" #endif #ifdef CONFIG_GLUSTERFS_ZEROFILL ", full" #endif ")" }, { .name = GLUSTER_OPT_DEBUG, .type = QEMU_OPT_NUMBER, .help = "Gluster log level, valid range is 0-9", }, { .name = GLUSTER_OPT_LOGFILE, .type = QEMU_OPT_STRING, .help = "Logfile path of libgfapi", }, { /* end of list */ } } }; static QemuOptsList runtime_opts = { .name = "gluster", .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), .desc = { { .name = GLUSTER_OPT_FILENAME, .type = QEMU_OPT_STRING, .help = "URL to the gluster image", }, { .name = GLUSTER_OPT_DEBUG, .type = QEMU_OPT_NUMBER, .help = "Gluster log level, valid range is 0-9", }, { .name = GLUSTER_OPT_LOGFILE, .type = QEMU_OPT_STRING, .help = "Logfile path of libgfapi", }, { /* end of list */ } }, }; static QemuOptsList runtime_json_opts = { .name = "gluster_json", .head = QTAILQ_HEAD_INITIALIZER(runtime_json_opts.head), .desc = { { .name = GLUSTER_OPT_VOLUME, .type = QEMU_OPT_STRING, .help = "name of gluster volume where VM image resides", }, { .name = GLUSTER_OPT_PATH, .type = QEMU_OPT_STRING, .help = "absolute path to image file in gluster volume", }, { .name = GLUSTER_OPT_DEBUG, .type = QEMU_OPT_NUMBER, .help = "Gluster log level, valid range is 0-9", }, { /* end of list */ } }, }; static QemuOptsList runtime_type_opts = { .name = "gluster_type", .head = QTAILQ_HEAD_INITIALIZER(runtime_type_opts.head), .desc = { { .name = GLUSTER_OPT_TYPE, .type = QEMU_OPT_STRING, .help = "inet|unix", }, { /* end of list */ } }, }; static QemuOptsList runtime_unix_opts = { .name = "gluster_unix", .head = QTAILQ_HEAD_INITIALIZER(runtime_unix_opts.head), .desc = { { .name = GLUSTER_OPT_SOCKET, .type = QEMU_OPT_STRING, .help = "socket file path (legacy)", }, { .name = GLUSTER_OPT_PATH, .type = QEMU_OPT_STRING, .help = "socket file path (QAPI)", }, { /* end of list */ } }, }; static QemuOptsList runtime_inet_opts = { .name = "gluster_inet", .head = QTAILQ_HEAD_INITIALIZER(runtime_inet_opts.head), .desc = { { .name = GLUSTER_OPT_TYPE, .type = QEMU_OPT_STRING, .help = "inet|unix", }, { .name = GLUSTER_OPT_HOST, .type = QEMU_OPT_STRING, .help = "host address (hostname/ipv4/ipv6 addresses)", }, { .name = GLUSTER_OPT_PORT, .type = QEMU_OPT_STRING, .help = "port number on which glusterd is listening (default 24007)", }, { .name = "to", .type = QEMU_OPT_NUMBER, .help = "max port number, not supported by gluster", }, { .name = "ipv4", .type = QEMU_OPT_BOOL, .help = "ipv4 bool value, not supported by gluster", }, { .name = "ipv6", .type = QEMU_OPT_BOOL, .help = "ipv6 bool value, not supported by gluster", }, { /* end of list */ } }, }; static void glfs_set_preopened(const char *volume, glfs_t *fs) { ListElement *entry = NULL; entry = g_new(ListElement, 1); entry->saved.volume = g_strdup(volume); entry->saved.fs = fs; entry->saved.ref = 1; QLIST_INSERT_HEAD(&glfs_list, entry, list); } static glfs_t *glfs_find_preopened(const char *volume) { ListElement *entry = NULL; QLIST_FOREACH(entry, &glfs_list, list) { if (strcmp(entry->saved.volume, volume) == 0) { entry->saved.ref++; return entry->saved.fs; } } return NULL; } static void glfs_clear_preopened(glfs_t *fs) { ListElement *entry = NULL; ListElement *next; if (fs == NULL) { return; } QLIST_FOREACH_SAFE(entry, &glfs_list, list, next) { if (entry->saved.fs == fs) { if (--entry->saved.ref) { return; } QLIST_REMOVE(entry, list); glfs_fini(entry->saved.fs); g_free(entry->saved.volume); g_free(entry); } } } static int parse_volume_options(BlockdevOptionsGluster *gconf, char *path) { char *p, *q; if (!path) { return -EINVAL; } /* volume */ p = q = path + strspn(path, "/"); p += strcspn(p, "/"); if (*p == '\0') { return -EINVAL; } gconf->volume = g_strndup(q, p - q); /* path */ p += strspn(p, "/"); if (*p == '\0') { return -EINVAL; } gconf->path = g_strdup(p); return 0; } /* * file=gluster[+transport]://[host[:port]]/volume/path[?socket=...] * * 'gluster' is the protocol. * * 'transport' specifies the transport type used to connect to gluster * management daemon (glusterd). Valid transport types are * tcp or unix. If a transport type isn't specified, then tcp type is assumed. * * 'host' specifies the host where the volume file specification for * the given volume resides. This can be either hostname or ipv4 address. * If transport type is 'unix', then 'host' field should not be specified. * The 'socket' field needs to be populated with the path to unix domain * socket. * * 'port' is the port number on which glusterd is listening. This is optional * and if not specified, QEMU will send 0 which will make gluster to use the * default port. If the transport type is unix, then 'port' should not be * specified. * * 'volume' is the name of the gluster volume which contains the VM image. * * 'path' is the path to the actual VM image that resides on gluster volume. * * Examples: * * file=gluster://1.2.3.4/testvol/a.img * file=gluster+tcp://1.2.3.4/testvol/a.img * file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img * file=gluster+tcp://host.domain.com:24007/testvol/dir/a.img * file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket */ static int qemu_gluster_parse_uri(BlockdevOptionsGluster *gconf, const char *filename) { SocketAddress *gsconf; URI *uri; QueryParams *qp = NULL; bool is_unix = false; int ret = 0; uri = uri_parse(filename); if (!uri) { return -EINVAL; } gsconf = g_new0(SocketAddress, 1); QAPI_LIST_PREPEND(gconf->server, gsconf); /* transport */ if (!uri->scheme || !strcmp(uri->scheme, "gluster")) { gsconf->type = SOCKET_ADDRESS_TYPE_INET; } else if (!strcmp(uri->scheme, "gluster+tcp")) { gsconf->type = SOCKET_ADDRESS_TYPE_INET; } else if (!strcmp(uri->scheme, "gluster+unix")) { gsconf->type = SOCKET_ADDRESS_TYPE_UNIX; is_unix = true; } else if (!strcmp(uri->scheme, "gluster+rdma")) { gsconf->type = SOCKET_ADDRESS_TYPE_INET; warn_report("rdma feature is not supported, falling back to tcp"); } else { ret = -EINVAL; goto out; } ret = parse_volume_options(gconf, uri->path); if (ret < 0) { goto out; } qp = query_params_parse(uri->query); if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { ret = -EINVAL; goto out; } if (is_unix) { if (uri->server || uri->port) { ret = -EINVAL; goto out; } if (strcmp(qp->p[0].name, "socket")) { ret = -EINVAL; goto out; } gsconf->u.q_unix.path = g_strdup(qp->p[0].value); } else { gsconf->u.inet.host = g_strdup(uri->server ? uri->server : "localhost"); if (uri->port) { gsconf->u.inet.port = g_strdup_printf("%d", uri->port); } else { gsconf->u.inet.port = g_strdup_printf("%d", GLUSTER_DEFAULT_PORT); } } out: if (qp) { query_params_free(qp); } uri_free(uri); return ret; } static struct glfs *qemu_gluster_glfs_init(BlockdevOptionsGluster *gconf, Error **errp) { struct glfs *glfs; int ret; int old_errno; SocketAddressList *server; unsigned long long port; glfs = glfs_find_preopened(gconf->volume); if (glfs) { return glfs; } glfs = glfs_new(gconf->volume); if (!glfs) { goto out; } glfs_set_preopened(gconf->volume, glfs); for (server = gconf->server; server; server = server->next) { switch (server->value->type) { case SOCKET_ADDRESS_TYPE_UNIX: ret = glfs_set_volfile_server(glfs, "unix", server->value->u.q_unix.path, 0); break; case SOCKET_ADDRESS_TYPE_INET: if (parse_uint_full(server->value->u.inet.port, &port, 10) < 0 || port > 65535) { error_setg(errp, "'%s' is not a valid port number", server->value->u.inet.port); errno = EINVAL; goto out; } ret = glfs_set_volfile_server(glfs, "tcp", server->value->u.inet.host, (int)port); break; case SOCKET_ADDRESS_TYPE_VSOCK: case SOCKET_ADDRESS_TYPE_FD: default: abort(); } if (ret < 0) { goto out; } } ret = glfs_set_logging(glfs, gconf->logfile, gconf->debug); if (ret < 0) { goto out; } ret = glfs_init(glfs); if (ret) { error_setg(errp, "Gluster connection for volume %s, path %s failed" " to connect", gconf->volume, gconf->path); for (server = gconf->server; server; server = server->next) { if (server->value->type == SOCKET_ADDRESS_TYPE_UNIX) { error_append_hint(errp, "hint: failed on socket %s ", server->value->u.q_unix.path); } else { error_append_hint(errp, "hint: failed on host %s and port %s ", server->value->u.inet.host, server->value->u.inet.port); } } error_append_hint(errp, "Please refer to gluster logs for more info\n"); /* glfs_init sometimes doesn't set errno although docs suggest that */ if (errno == 0) { errno = EINVAL; } goto out; } return glfs; out: if (glfs) { old_errno = errno; glfs_clear_preopened(glfs); errno = old_errno; } return NULL; } /* * Convert the json formatted command line into qapi. */ static int qemu_gluster_parse_json(BlockdevOptionsGluster *gconf, QDict *options, Error **errp) { QemuOpts *opts; SocketAddress *gsconf = NULL; SocketAddressList **tail; QDict *backing_options = NULL; Error *local_err = NULL; char *str = NULL; const char *ptr; int i, type, num_servers; /* create opts info from runtime_json_opts list */ opts = qemu_opts_create(&runtime_json_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, options, errp)) { goto out; } num_servers = qdict_array_entries(options, GLUSTER_OPT_SERVER_PATTERN); if (num_servers < 1) { error_setg(&local_err, QERR_MISSING_PARAMETER, "server"); goto out; } ptr = qemu_opt_get(opts, GLUSTER_OPT_VOLUME); if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_VOLUME); goto out; } gconf->volume = g_strdup(ptr); ptr = qemu_opt_get(opts, GLUSTER_OPT_PATH); if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_PATH); goto out; } gconf->path = g_strdup(ptr); qemu_opts_del(opts); tail = &gconf->server; for (i = 0; i < num_servers; i++) { str = g_strdup_printf(GLUSTER_OPT_SERVER_PATTERN"%d.", i); qdict_extract_subqdict(options, &backing_options, str); /* create opts info from runtime_type_opts list */ opts = qemu_opts_create(&runtime_type_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, backing_options, errp)) { goto out; } ptr = qemu_opt_get(opts, GLUSTER_OPT_TYPE); if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_TYPE); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } gsconf = g_new0(SocketAddress, 1); if (!strcmp(ptr, "tcp")) { ptr = "inet"; /* accept legacy "tcp" */ } type = qapi_enum_parse(&SocketAddressType_lookup, ptr, -1, NULL); if (type != SOCKET_ADDRESS_TYPE_INET && type != SOCKET_ADDRESS_TYPE_UNIX) { error_setg(&local_err, "Parameter '%s' may be 'inet' or 'unix'", GLUSTER_OPT_TYPE); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } gsconf->type = type; qemu_opts_del(opts); if (gsconf->type == SOCKET_ADDRESS_TYPE_INET) { /* create opts info from runtime_inet_opts list */ opts = qemu_opts_create(&runtime_inet_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, backing_options, errp)) { goto out; } ptr = qemu_opt_get(opts, GLUSTER_OPT_HOST); if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_HOST); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } gsconf->u.inet.host = g_strdup(ptr); ptr = qemu_opt_get(opts, GLUSTER_OPT_PORT); if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_PORT); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } gsconf->u.inet.port = g_strdup(ptr); /* defend for unsupported fields in InetSocketAddress, * i.e. @ipv4, @ipv6 and @to */ ptr = qemu_opt_get(opts, GLUSTER_OPT_TO); if (ptr) { gsconf->u.inet.has_to = true; } ptr = qemu_opt_get(opts, GLUSTER_OPT_IPV4); if (ptr) { gsconf->u.inet.has_ipv4 = true; } ptr = qemu_opt_get(opts, GLUSTER_OPT_IPV6); if (ptr) { gsconf->u.inet.has_ipv6 = true; } if (gsconf->u.inet.has_to) { error_setg(&local_err, "Parameter 'to' not supported"); goto out; } if (gsconf->u.inet.has_ipv4 || gsconf->u.inet.has_ipv6) { error_setg(&local_err, "Parameters 'ipv4/ipv6' not supported"); goto out; } qemu_opts_del(opts); } else { /* create opts info from runtime_unix_opts list */ opts = qemu_opts_create(&runtime_unix_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, backing_options, errp)) { goto out; } ptr = qemu_opt_get(opts, GLUSTER_OPT_PATH); if (!ptr) { ptr = qemu_opt_get(opts, GLUSTER_OPT_SOCKET); } else if (qemu_opt_get(opts, GLUSTER_OPT_SOCKET)) { error_setg(&local_err, "Conflicting parameters 'path' and 'socket'"); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } if (!ptr) { error_setg(&local_err, QERR_MISSING_PARAMETER, GLUSTER_OPT_PATH); error_append_hint(&local_err, GERR_INDEX_HINT, i); goto out; } gsconf->u.q_unix.path = g_strdup(ptr); qemu_opts_del(opts); } QAPI_LIST_APPEND(tail, gsconf); gsconf = NULL; qobject_unref(backing_options); backing_options = NULL; g_free(str); str = NULL; } return 0; out: error_propagate(errp, local_err); qapi_free_SocketAddress(gsconf); qemu_opts_del(opts); g_free(str); qobject_unref(backing_options); errno = EINVAL; return -errno; } /* Converts options given in @filename and the @options QDict into the QAPI * object @gconf. */ static int qemu_gluster_parse(BlockdevOptionsGluster *gconf, const char *filename, QDict *options, Error **errp) { int ret; if (filename) { ret = qemu_gluster_parse_uri(gconf, filename); if (ret < 0) { error_setg(errp, "invalid URI %s", filename); error_append_hint(errp, "Usage: file=gluster[+transport]://" "[host[:port]]volume/path[?socket=...]" "[,file.debug=N]" "[,file.logfile=/path/filename.log]\n"); return ret; } } else { ret = qemu_gluster_parse_json(gconf, options, errp); if (ret < 0) { error_append_hint(errp, "Usage: " "-drive driver=qcow2,file.driver=gluster," "file.volume=testvol,file.path=/path/a.qcow2" "[,file.debug=9]" "[,file.logfile=/path/filename.log]," "file.server.0.type=inet," "file.server.0.host=1.2.3.4," "file.server.0.port=24007," "file.server.1.transport=unix," "file.server.1.path=/var/run/glusterd.socket ..." "\n"); return ret; } } return 0; } static struct glfs *qemu_gluster_init(BlockdevOptionsGluster *gconf, const char *filename, QDict *options, Error **errp) { int ret; ret = qemu_gluster_parse(gconf, filename, options, errp); if (ret < 0) { errno = -ret; return NULL; } return qemu_gluster_glfs_init(gconf, errp); } /* * AIO callback routine called from GlusterFS thread. */ static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, #ifdef CONFIG_GLUSTERFS_IOCB_HAS_STAT struct glfs_stat *pre, struct glfs_stat *post, #endif void *arg) { GlusterAIOCB *acb = (GlusterAIOCB *)arg; if (!ret || ret == acb->size) { acb->ret = 0; /* Success */ } else if (ret < 0) { acb->ret = -errno; /* Read/Write failed */ } else { acb->ret = -EIO; /* Partial read/write - fail it */ } aio_co_schedule(acb->aio_context, acb->coroutine); } static void qemu_gluster_parse_flags(int bdrv_flags, int *open_flags) { assert(open_flags != NULL); *open_flags |= O_BINARY; if (bdrv_flags & BDRV_O_RDWR) { *open_flags |= O_RDWR; } else { *open_flags |= O_RDONLY; } if ((bdrv_flags & BDRV_O_NOCACHE)) { *open_flags |= O_DIRECT; } } /* * Do SEEK_DATA/HOLE to detect if it is functional. Older broken versions of * gfapi incorrectly return the current offset when SEEK_DATA/HOLE is used. * - Corrected versions return -1 and set errno to EINVAL. * - Versions that support SEEK_DATA/HOLE correctly, will return -1 and set * errno to ENXIO when SEEK_DATA is called with a position of EOF. */ static bool qemu_gluster_test_seek(struct glfs_fd *fd) { off_t ret = 0; #if defined SEEK_HOLE && defined SEEK_DATA off_t eof; eof = glfs_lseek(fd, 0, SEEK_END); if (eof < 0) { /* this should never occur */ return false; } /* this should always fail with ENXIO if SEEK_DATA is supported */ ret = glfs_lseek(fd, eof, SEEK_DATA); #endif return (ret < 0) && (errno == ENXIO); } static int qemu_gluster_open(BlockDriverState *bs, QDict *options, int bdrv_flags, Error **errp) { BDRVGlusterState *s = bs->opaque; int open_flags = 0; int ret = 0; BlockdevOptionsGluster *gconf = NULL; QemuOpts *opts; const char *filename, *logfile; opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, options, errp)) { ret = -EINVAL; goto out; } filename = qemu_opt_get(opts, GLUSTER_OPT_FILENAME); s->debug = qemu_opt_get_number(opts, GLUSTER_OPT_DEBUG, GLUSTER_DEBUG_DEFAULT); if (s->debug < 0) { s->debug = 0; } else if (s->debug > GLUSTER_DEBUG_MAX) { s->debug = GLUSTER_DEBUG_MAX; } gconf = g_new0(BlockdevOptionsGluster, 1); gconf->debug = s->debug; gconf->has_debug = true; logfile = qemu_opt_get(opts, GLUSTER_OPT_LOGFILE); s->logfile = g_strdup(logfile ? logfile : GLUSTER_LOGFILE_DEFAULT); gconf->logfile = g_strdup(s->logfile); gconf->has_logfile = true; s->glfs = qemu_gluster_init(gconf, filename, options, errp); if (!s->glfs) { ret = -errno; goto out; } #ifdef CONFIG_GLUSTERFS_XLATOR_OPT /* Without this, if fsync fails for a recoverable reason (for instance, * ENOSPC), gluster will dump its cache, preventing retries. This means * almost certain data loss. Not all gluster versions support the * 'resync-failed-syncs-after-fsync' key value, but there is no way to * discover during runtime if it is supported (this api returns success for * unknown key/value pairs) */ ret = glfs_set_xlator_option(s->glfs, "*-write-behind", "resync-failed-syncs-after-fsync", "on"); if (ret < 0) { error_setg_errno(errp, errno, "Unable to set xlator key/value pair"); ret = -errno; goto out; } #endif qemu_gluster_parse_flags(bdrv_flags, &open_flags); s->fd = glfs_open(s->glfs, gconf->path, open_flags); ret = s->fd ? 0 : -errno; if (ret == -EACCES || ret == -EROFS) { /* Try to degrade to read-only, but if it doesn't work, still use the * normal error message. */ if (bdrv_apply_auto_read_only(bs, NULL, NULL) == 0) { open_flags = (open_flags & ~O_RDWR) | O_RDONLY; s->fd = glfs_open(s->glfs, gconf->path, open_flags); ret = s->fd ? 0 : -errno; } } s->supports_seek_data = qemu_gluster_test_seek(s->fd); out: qemu_opts_del(opts); qapi_free_BlockdevOptionsGluster(gconf); if (!ret) { return ret; } g_free(s->logfile); if (s->fd) { glfs_close(s->fd); } glfs_clear_preopened(s->glfs); return ret; } static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp) { bs->bl.max_transfer = GLUSTER_MAX_TRANSFER; bs->bl.max_pdiscard = SIZE_MAX; } static int qemu_gluster_reopen_prepare(BDRVReopenState *state, BlockReopenQueue *queue, Error **errp) { int ret = 0; BDRVGlusterState *s; BDRVGlusterReopenState *reop_s; BlockdevOptionsGluster *gconf; int open_flags = 0; assert(state != NULL); assert(state->bs != NULL); s = state->bs->opaque; state->opaque = g_new0(BDRVGlusterReopenState, 1); reop_s = state->opaque; qemu_gluster_parse_flags(state->flags, &open_flags); gconf = g_new0(BlockdevOptionsGluster, 1); gconf->debug = s->debug; gconf->has_debug = true; gconf->logfile = g_strdup(s->logfile); gconf->has_logfile = true; /* * If 'state->bs->exact_filename' is empty, 'state->options' should contain * the JSON parameters already parsed. */ if (state->bs->exact_filename[0] != '\0') { reop_s->glfs = qemu_gluster_init(gconf, state->bs->exact_filename, NULL, errp); } else { reop_s->glfs = qemu_gluster_init(gconf, NULL, state->options, errp); } if (reop_s->glfs == NULL) { ret = -errno; goto exit; } #ifdef CONFIG_GLUSTERFS_XLATOR_OPT ret = glfs_set_xlator_option(reop_s->glfs, "*-write-behind", "resync-failed-syncs-after-fsync", "on"); if (ret < 0) { error_setg_errno(errp, errno, "Unable to set xlator key/value pair"); ret = -errno; goto exit; } #endif reop_s->fd = glfs_open(reop_s->glfs, gconf->path, open_flags); if (reop_s->fd == NULL) { /* reops->glfs will be cleaned up in _abort */ ret = -errno; goto exit; } exit: /* state->opaque will be freed in either the _abort or _commit */ qapi_free_BlockdevOptionsGluster(gconf); return ret; } static void qemu_gluster_reopen_commit(BDRVReopenState *state) { BDRVGlusterReopenState *reop_s = state->opaque; BDRVGlusterState *s = state->bs->opaque; /* close the old */ if (s->fd) { glfs_close(s->fd); } glfs_clear_preopened(s->glfs); /* use the newly opened image / connection */ s->fd = reop_s->fd; s->glfs = reop_s->glfs; g_free(state->opaque); state->opaque = NULL; return; } static void qemu_gluster_reopen_abort(BDRVReopenState *state) { BDRVGlusterReopenState *reop_s = state->opaque; if (reop_s == NULL) { return; } if (reop_s->fd) { glfs_close(reop_s->fd); } glfs_clear_preopened(reop_s->glfs); g_free(state->opaque); state->opaque = NULL; return; } #ifdef CONFIG_GLUSTERFS_ZEROFILL static coroutine_fn int qemu_gluster_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, BdrvRequestFlags flags) { int ret; GlusterAIOCB acb; BDRVGlusterState *s = bs->opaque; acb.size = bytes; acb.ret = 0; acb.coroutine = qemu_coroutine_self(); acb.aio_context = bdrv_get_aio_context(bs); ret = glfs_zerofill_async(s->fd, offset, bytes, gluster_finish_aiocb, &acb); if (ret < 0) { return -errno; } qemu_coroutine_yield(); return acb.ret; } #endif static int qemu_gluster_do_truncate(struct glfs_fd *fd, int64_t offset, PreallocMode prealloc, Error **errp) { int64_t current_length; current_length = glfs_lseek(fd, 0, SEEK_END); if (current_length < 0) { error_setg_errno(errp, errno, "Failed to determine current size"); return -errno; } if (current_length > offset && prealloc != PREALLOC_MODE_OFF) { error_setg(errp, "Cannot use preallocation for shrinking files"); return -ENOTSUP; } if (current_length == offset) { return 0; } switch (prealloc) { #ifdef CONFIG_GLUSTERFS_FALLOCATE case PREALLOC_MODE_FALLOC: if (glfs_fallocate(fd, 0, current_length, offset - current_length)) { error_setg_errno(errp, errno, "Could not preallocate data"); return -errno; } break; #endif /* CONFIG_GLUSTERFS_FALLOCATE */ #ifdef CONFIG_GLUSTERFS_ZEROFILL case PREALLOC_MODE_FULL: if (glfs_ftruncate(fd, offset)) { error_setg_errno(errp, errno, "Could not resize file"); return -errno; } if (glfs_zerofill(fd, current_length, offset - current_length)) { error_setg_errno(errp, errno, "Could not zerofill the new area"); return -errno; } break; #endif /* CONFIG_GLUSTERFS_ZEROFILL */ case PREALLOC_MODE_OFF: if (glfs_ftruncate(fd, offset)) { error_setg_errno(errp, errno, "Could not resize file"); return -errno; } break; default: error_setg(errp, "Unsupported preallocation mode: %s", PreallocMode_str(prealloc)); return -EINVAL; } return 0; } static int qemu_gluster_co_create(BlockdevCreateOptions *options, Error **errp) { BlockdevCreateOptionsGluster *opts = &options->u.gluster; struct glfs *glfs; struct glfs_fd *fd = NULL; int ret = 0; assert(options->driver == BLOCKDEV_DRIVER_GLUSTER); glfs = qemu_gluster_glfs_init(opts->location, errp); if (!glfs) { ret = -errno; goto out; } fd = glfs_creat(glfs, opts->location->path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR); if (!fd) { ret = -errno; goto out; } ret = qemu_gluster_do_truncate(fd, opts->size, opts->preallocation, errp); out: if (fd) { if (glfs_close(fd) != 0 && ret == 0) { ret = -errno; } } glfs_clear_preopened(glfs); return ret; } static int coroutine_fn qemu_gluster_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, Error **errp) { BlockdevCreateOptions *options; BlockdevCreateOptionsGluster *gopts; BlockdevOptionsGluster *gconf; char *tmp = NULL; Error *local_err = NULL; int ret; options = g_new0(BlockdevCreateOptions, 1); options->driver = BLOCKDEV_DRIVER_GLUSTER; gopts = &options->u.gluster; gconf = g_new0(BlockdevOptionsGluster, 1); gopts->location = gconf; gopts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); tmp = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); gopts->preallocation = qapi_enum_parse(&PreallocMode_lookup, tmp, PREALLOC_MODE_OFF, &local_err); g_free(tmp); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } gconf->debug = qemu_opt_get_number_del(opts, GLUSTER_OPT_DEBUG, GLUSTER_DEBUG_DEFAULT); if (gconf->debug < 0) { gconf->debug = 0; } else if (gconf->debug > GLUSTER_DEBUG_MAX) { gconf->debug = GLUSTER_DEBUG_MAX; } gconf->has_debug = true; gconf->logfile = qemu_opt_get_del(opts, GLUSTER_OPT_LOGFILE); if (!gconf->logfile) { gconf->logfile = g_strdup(GLUSTER_LOGFILE_DEFAULT); } gconf->has_logfile = true; ret = qemu_gluster_parse(gconf, filename, NULL, errp); if (ret < 0) { goto fail; } ret = qemu_gluster_co_create(options, errp); if (ret < 0) { goto fail; } ret = 0; fail: qapi_free_BlockdevCreateOptions(options); return ret; } static coroutine_fn int qemu_gluster_co_rw(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int write) { int ret; GlusterAIOCB acb; BDRVGlusterState *s = bs->opaque; size_t size = nb_sectors * BDRV_SECTOR_SIZE; off_t offset = sector_num * BDRV_SECTOR_SIZE; acb.size = size; acb.ret = 0; acb.coroutine = qemu_coroutine_self(); acb.aio_context = bdrv_get_aio_context(bs); if (write) { ret = glfs_pwritev_async(s->fd, qiov->iov, qiov->niov, offset, 0, gluster_finish_aiocb, &acb); } else { ret = glfs_preadv_async(s->fd, qiov->iov, qiov->niov, offset, 0, gluster_finish_aiocb, &acb); } if (ret < 0) { return -errno; } qemu_coroutine_yield(); return acb.ret; } static coroutine_fn int qemu_gluster_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) { BDRVGlusterState *s = bs->opaque; return qemu_gluster_do_truncate(s->fd, offset, prealloc, errp); } static coroutine_fn int qemu_gluster_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 0); } static coroutine_fn int qemu_gluster_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags) { assert(!flags); return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 1); } static void qemu_gluster_close(BlockDriverState *bs) { BDRVGlusterState *s = bs->opaque; g_free(s->logfile); if (s->fd) { glfs_close(s->fd); s->fd = NULL; } glfs_clear_preopened(s->glfs); } static coroutine_fn int qemu_gluster_co_flush_to_disk(BlockDriverState *bs) { int ret; GlusterAIOCB acb; BDRVGlusterState *s = bs->opaque; acb.size = 0; acb.ret = 0; acb.coroutine = qemu_coroutine_self(); acb.aio_context = bdrv_get_aio_context(bs); ret = glfs_fsync_async(s->fd, gluster_finish_aiocb, &acb); if (ret < 0) { ret = -errno; goto error; } qemu_coroutine_yield(); if (acb.ret < 0) { ret = acb.ret; goto error; } return acb.ret; error: /* Some versions of Gluster (3.5.6 -> 3.5.8?) will not retain its cache * after a fsync failure, so we have no way of allowing the guest to safely * continue. Gluster versions prior to 3.5.6 don't retain the cache * either, but will invalidate the fd on error, so this is again our only * option. * * The 'resync-failed-syncs-after-fsync' xlator option for the * write-behind cache will cause later gluster versions to retain its * cache after error, so long as the fd remains open. However, we * currently have no way of knowing if this option is supported. * * TODO: Once gluster provides a way for us to determine if the option * is supported, bypass the closure and setting drv to NULL. */ qemu_gluster_close(bs); bs->drv = NULL; return ret; } #ifdef CONFIG_GLUSTERFS_DISCARD static coroutine_fn int qemu_gluster_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) { int ret; GlusterAIOCB acb; BDRVGlusterState *s = bs->opaque; assert(bytes <= SIZE_MAX); /* rely on max_pdiscard */ acb.size = 0; acb.ret = 0; acb.coroutine = qemu_coroutine_self(); acb.aio_context = bdrv_get_aio_context(bs); ret = glfs_discard_async(s->fd, offset, bytes, gluster_finish_aiocb, &acb); if (ret < 0) { return -errno; } qemu_coroutine_yield(); return acb.ret; } #endif static int64_t qemu_gluster_getlength(BlockDriverState *bs) { BDRVGlusterState *s = bs->opaque; int64_t ret; ret = glfs_lseek(s->fd, 0, SEEK_END); if (ret < 0) { return -errno; } else { return ret; } } static int64_t qemu_gluster_allocated_file_size(BlockDriverState *bs) { BDRVGlusterState *s = bs->opaque; struct stat st; int ret; ret = glfs_fstat(s->fd, &st); if (ret < 0) { return -errno; } else { return st.st_blocks * 512; } } /* * Find allocation range in @bs around offset @start. * May change underlying file descriptor's file offset. * If @start is not in a hole, store @start in @data, and the * beginning of the next hole in @hole, and return 0. * If @start is in a non-trailing hole, store @start in @hole and the * beginning of the next non-hole in @data, and return 0. * If @start is in a trailing hole or beyond EOF, return -ENXIO. * If we can't find out, return a negative errno other than -ENXIO. * * (Shamefully copied from file-posix.c, only minuscule adaptions.) */ static int find_allocation(BlockDriverState *bs, off_t start, off_t *data, off_t *hole) { BDRVGlusterState *s = bs->opaque; if (!s->supports_seek_data) { goto exit; } #if defined SEEK_HOLE && defined SEEK_DATA off_t offs; /* * SEEK_DATA cases: * D1. offs == start: start is in data * D2. offs > start: start is in a hole, next data at offs * D3. offs < 0, errno = ENXIO: either start is in a trailing hole * or start is beyond EOF * If the latter happens, the file has been truncated behind * our back since we opened it. All bets are off then. * Treating like a trailing hole is simplest. * D4. offs < 0, errno != ENXIO: we learned nothing */ offs = glfs_lseek(s->fd, start, SEEK_DATA); if (offs < 0) { return -errno; /* D3 or D4 */ } if (offs < start) { /* This is not a valid return by lseek(). We are safe to just return * -EIO in this case, and we'll treat it like D4. Unfortunately some * versions of gluster server will return offs < start, so an assert * here will unnecessarily abort QEMU. */ return -EIO; } if (offs > start) { /* D2: in hole, next data at offs */ *hole = start; *data = offs; return 0; } /* D1: in data, end not yet known */ /* * SEEK_HOLE cases: * H1. offs == start: start is in a hole * If this happens here, a hole has been dug behind our back * since the previous lseek(). * H2. offs > start: either start is in data, next hole at offs, * or start is in trailing hole, EOF at offs * Linux treats trailing holes like any other hole: offs == * start. Solaris seeks to EOF instead: offs > start (blech). * If that happens here, a hole has been dug behind our back * since the previous lseek(). * H3. offs < 0, errno = ENXIO: start is beyond EOF * If this happens, the file has been truncated behind our * back since we opened it. Treat it like a trailing hole. * H4. offs < 0, errno != ENXIO: we learned nothing * Pretend we know nothing at all, i.e. "forget" about D1. */ offs = glfs_lseek(s->fd, start, SEEK_HOLE); if (offs < 0) { return -errno; /* D1 and (H3 or H4) */ } if (offs < start) { /* This is not a valid return by lseek(). We are safe to just return * -EIO in this case, and we'll treat it like H4. Unfortunately some * versions of gluster server will return offs < start, so an assert * here will unnecessarily abort QEMU. */ return -EIO; } if (offs > start) { /* * D1 and H2: either in data, next hole at offs, or it was in * data but is now in a trailing hole. In the latter case, * all bets are off. Treating it as if it there was data all * the way to EOF is safe, so simply do that. */ *data = start; *hole = offs; return 0; } /* D1 and H1 */ return -EBUSY; #endif exit: return -ENOTSUP; } /* * Returns the allocation status of the specified offset. * * The block layer guarantees 'offset' and 'bytes' are within bounds. * * 'pnum' is set to the number of bytes (including and immediately following * the specified offset) that are known to be in the same * allocated/unallocated state. * * 'bytes' is a soft cap for 'pnum'. If the information is free, 'pnum' may * well exceed it. * * (Based on raw_co_block_status() from file-posix.c.) */ static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file) { BDRVGlusterState *s = bs->opaque; off_t data = 0, hole = 0; int ret = -EINVAL; assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment)); if (!s->fd) { return ret; } if (!want_zero) { *pnum = bytes; *map = offset; *file = bs; return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; } ret = find_allocation(bs, offset, &data, &hole); if (ret == -ENXIO) { /* Trailing hole */ *pnum = bytes; ret = BDRV_BLOCK_ZERO; } else if (ret < 0) { /* No info available, so pretend there are no holes */ *pnum = bytes; ret = BDRV_BLOCK_DATA; } else if (data == offset) { /* On a data extent, compute bytes to the end of the extent, * possibly including a partial sector at EOF. */ *pnum = hole - offset; /* * We are not allowed to return partial sectors, though, so * round up if necessary. */ if (!QEMU_IS_ALIGNED(*pnum, bs->bl.request_alignment)) { int64_t file_length = qemu_gluster_getlength(bs); if (file_length > 0) { /* Ignore errors, this is just a safeguard */ assert(hole == file_length); } *pnum = ROUND_UP(*pnum, bs->bl.request_alignment); } ret = BDRV_BLOCK_DATA; } else { /* On a hole, compute bytes to the beginning of the next extent. */ assert(hole == offset); *pnum = data - offset; ret = BDRV_BLOCK_ZERO; } *map = offset; *file = bs; return ret | BDRV_BLOCK_OFFSET_VALID; } static const char *const gluster_strong_open_opts[] = { GLUSTER_OPT_VOLUME, GLUSTER_OPT_PATH, GLUSTER_OPT_TYPE, GLUSTER_OPT_SERVER_PATTERN, GLUSTER_OPT_HOST, GLUSTER_OPT_PORT, GLUSTER_OPT_TO, GLUSTER_OPT_IPV4, GLUSTER_OPT_IPV6, GLUSTER_OPT_SOCKET, NULL }; static BlockDriver bdrv_gluster = { .format_name = "gluster", .protocol_name = "gluster", .instance_size = sizeof(BDRVGlusterState), .bdrv_needs_filename = false, .bdrv_file_open = qemu_gluster_open, .bdrv_reopen_prepare = qemu_gluster_reopen_prepare, .bdrv_reopen_commit = qemu_gluster_reopen_commit, .bdrv_reopen_abort = qemu_gluster_reopen_abort, .bdrv_close = qemu_gluster_close, .bdrv_co_create = qemu_gluster_co_create, .bdrv_co_create_opts = qemu_gluster_co_create_opts, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_co_truncate = qemu_gluster_co_truncate, .bdrv_co_readv = qemu_gluster_co_readv, .bdrv_co_writev = qemu_gluster_co_writev, .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk, #ifdef CONFIG_GLUSTERFS_DISCARD .bdrv_co_pdiscard = qemu_gluster_co_pdiscard, #endif #ifdef CONFIG_GLUSTERFS_ZEROFILL .bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes, #endif .bdrv_co_block_status = qemu_gluster_co_block_status, .bdrv_refresh_limits = qemu_gluster_refresh_limits, .create_opts = &qemu_gluster_create_opts, .strong_runtime_opts = gluster_strong_open_opts, }; static BlockDriver bdrv_gluster_tcp = { .format_name = "gluster", .protocol_name = "gluster+tcp", .instance_size = sizeof(BDRVGlusterState), .bdrv_needs_filename = false, .bdrv_file_open = qemu_gluster_open, .bdrv_reopen_prepare = qemu_gluster_reopen_prepare, .bdrv_reopen_commit = qemu_gluster_reopen_commit, .bdrv_reopen_abort = qemu_gluster_reopen_abort, .bdrv_close = qemu_gluster_close, .bdrv_co_create = qemu_gluster_co_create, .bdrv_co_create_opts = qemu_gluster_co_create_opts, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_co_truncate = qemu_gluster_co_truncate, .bdrv_co_readv = qemu_gluster_co_readv, .bdrv_co_writev = qemu_gluster_co_writev, .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk, #ifdef CONFIG_GLUSTERFS_DISCARD .bdrv_co_pdiscard = qemu_gluster_co_pdiscard, #endif #ifdef CONFIG_GLUSTERFS_ZEROFILL .bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes, #endif .bdrv_co_block_status = qemu_gluster_co_block_status, .bdrv_refresh_limits = qemu_gluster_refresh_limits, .create_opts = &qemu_gluster_create_opts, .strong_runtime_opts = gluster_strong_open_opts, }; static BlockDriver bdrv_gluster_unix = { .format_name = "gluster", .protocol_name = "gluster+unix", .instance_size = sizeof(BDRVGlusterState), .bdrv_needs_filename = true, .bdrv_file_open = qemu_gluster_open, .bdrv_reopen_prepare = qemu_gluster_reopen_prepare, .bdrv_reopen_commit = qemu_gluster_reopen_commit, .bdrv_reopen_abort = qemu_gluster_reopen_abort, .bdrv_close = qemu_gluster_close, .bdrv_co_create = qemu_gluster_co_create, .bdrv_co_create_opts = qemu_gluster_co_create_opts, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_co_truncate = qemu_gluster_co_truncate, .bdrv_co_readv = qemu_gluster_co_readv, .bdrv_co_writev = qemu_gluster_co_writev, .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk, #ifdef CONFIG_GLUSTERFS_DISCARD .bdrv_co_pdiscard = qemu_gluster_co_pdiscard, #endif #ifdef CONFIG_GLUSTERFS_ZEROFILL .bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes, #endif .bdrv_co_block_status = qemu_gluster_co_block_status, .bdrv_refresh_limits = qemu_gluster_refresh_limits, .create_opts = &qemu_gluster_create_opts, .strong_runtime_opts = gluster_strong_open_opts, }; /* rdma is deprecated (actually never supported for volfile fetch). * Let's maintain it for the protocol compatibility, to make sure things * won't break immediately. For now, gluster+rdma will fall back to gluster+tcp * protocol with a warning. * TODO: remove gluster+rdma interface support */ static BlockDriver bdrv_gluster_rdma = { .format_name = "gluster", .protocol_name = "gluster+rdma", .instance_size = sizeof(BDRVGlusterState), .bdrv_needs_filename = true, .bdrv_file_open = qemu_gluster_open, .bdrv_reopen_prepare = qemu_gluster_reopen_prepare, .bdrv_reopen_commit = qemu_gluster_reopen_commit, .bdrv_reopen_abort = qemu_gluster_reopen_abort, .bdrv_close = qemu_gluster_close, .bdrv_co_create = qemu_gluster_co_create, .bdrv_co_create_opts = qemu_gluster_co_create_opts, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_co_truncate = qemu_gluster_co_truncate, .bdrv_co_readv = qemu_gluster_co_readv, .bdrv_co_writev = qemu_gluster_co_writev, .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk, #ifdef CONFIG_GLUSTERFS_DISCARD .bdrv_co_pdiscard = qemu_gluster_co_pdiscard, #endif #ifdef CONFIG_GLUSTERFS_ZEROFILL .bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes, #endif .bdrv_co_block_status = qemu_gluster_co_block_status, .bdrv_refresh_limits = qemu_gluster_refresh_limits, .create_opts = &qemu_gluster_create_opts, .strong_runtime_opts = gluster_strong_open_opts, }; static void bdrv_gluster_init(void) { bdrv_register(&bdrv_gluster_rdma); bdrv_register(&bdrv_gluster_unix); bdrv_register(&bdrv_gluster_tcp); bdrv_register(&bdrv_gluster); } block_init(bdrv_gluster_init);