/* * GlusterFS backend for QEMU * * Copyright (C) 2012 Bharata B Rao * * Pipe handling mechanism in AIO implementation is derived from * block/rbd.c. Hence, * * Copyright (C) 2010-2011 Christian Brunner , * Josh Durgin * * 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 #include "block/block_int.h" #include "qemu/sockets.h" #include "qemu/uri.h" typedef struct GlusterAIOCB { BlockDriverAIOCB common; int64_t size; int ret; bool *finished; QEMUBH *bh; } GlusterAIOCB; typedef struct BDRVGlusterState { struct glfs *glfs; int fds[2]; struct glfs_fd *fd; int qemu_aio_count; int event_reader_pos; GlusterAIOCB *event_acb; } BDRVGlusterState; #define GLUSTER_FD_READ 0 #define GLUSTER_FD_WRITE 1 typedef struct GlusterConf { char *server; int port; char *volname; char *image; char *transport; } GlusterConf; static void qemu_gluster_gconf_free(GlusterConf *gconf) { g_free(gconf->server); g_free(gconf->volname); g_free(gconf->image); g_free(gconf->transport); g_free(gconf); } static int parse_volume_options(GlusterConf *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->volname = g_strndup(q, p - q); /* image */ p += strspn(p, "/"); if (*p == '\0') { return -EINVAL; } gconf->image = g_strdup(p); return 0; } /* * file=gluster[+transport]://[server[:port]]/volname/image[?socket=...] * * 'gluster' is the protocol. * * 'transport' specifies the transport type used to connect to gluster * management daemon (glusterd). Valid transport types are * tcp, unix and rdma. If a transport type isn't specified, then tcp * type is assumed. * * 'server' specifies the server where the volume file specification for * the given volume resides. This can be either hostname, ipv4 address * or ipv6 address. ipv6 address needs to be within square brackets [ ]. * If transport type is 'unix', then 'server' field should not be specifed. * 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. * * 'volname' is the name of the gluster volume which contains the VM image. * * 'image' 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://[1:2:3:4:5:6:7:8]/testvol/dir/a.img * file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img * file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img * file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket * file=gluster+rdma://1.2.3.4:24007/testvol/a.img */ static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename) { URI *uri; QueryParams *qp = NULL; bool is_unix = false; int ret = 0; uri = uri_parse(filename); if (!uri) { return -EINVAL; } /* transport */ if (!strcmp(uri->scheme, "gluster")) { gconf->transport = g_strdup("tcp"); } else if (!strcmp(uri->scheme, "gluster+tcp")) { gconf->transport = g_strdup("tcp"); } else if (!strcmp(uri->scheme, "gluster+unix")) { gconf->transport = g_strdup("unix"); is_unix = true; } else if (!strcmp(uri->scheme, "gluster+rdma")) { gconf->transport = g_strdup("rdma"); } 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; } gconf->server = g_strdup(qp->p[0].value); } else { gconf->server = g_strdup(uri->server); gconf->port = uri->port; } out: if (qp) { query_params_free(qp); } uri_free(uri); return ret; } static struct glfs *qemu_gluster_init(GlusterConf *gconf, const char *filename) { struct glfs *glfs = NULL; int ret; int old_errno; ret = qemu_gluster_parseuri(gconf, filename); if (ret < 0) { error_report("Usage: file=gluster[+transport]://[server[:port]]/" "volname/image[?socket=...]"); errno = -ret; goto out; } glfs = glfs_new(gconf->volname); if (!glfs) { goto out; } ret = glfs_set_volfile_server(glfs, gconf->transport, gconf->server, gconf->port); if (ret < 0) { goto out; } /* * TODO: Use GF_LOG_ERROR instead of hard code value of 4 here when * GlusterFS makes GF_LOG_* macros available to libgfapi users. */ ret = glfs_set_logging(glfs, "-", 4); if (ret < 0) { goto out; } ret = glfs_init(glfs); if (ret) { error_report("Gluster connection failed for server=%s port=%d " "volume=%s image=%s transport=%s\n", gconf->server, gconf->port, gconf->volname, gconf->image, gconf->transport); goto out; } return glfs; out: if (glfs) { old_errno = errno; glfs_fini(glfs); errno = old_errno; } return NULL; } static void qemu_gluster_complete_aio(GlusterAIOCB *acb, BDRVGlusterState *s) { int ret; bool *finished = acb->finished; BlockDriverCompletionFunc *cb = acb->common.cb; void *opaque = acb->common.opaque; if (!acb->ret || acb->ret == acb->size) { ret = 0; /* Success */ } else if (acb->ret < 0) { ret = acb->ret; /* Read/Write failed */ } else { ret = -EIO; /* Partial read/write - fail it */ } s->qemu_aio_count--; qemu_aio_release(acb); cb(opaque, ret); if (finished) { *finished = true; } } static void qemu_gluster_aio_event_reader(void *opaque) { BDRVGlusterState *s = opaque; ssize_t ret; do { char *p = (char *)&s->event_acb; ret = read(s->fds[GLUSTER_FD_READ], p + s->event_reader_pos, sizeof(s->event_acb) - s->event_reader_pos); if (ret > 0) { s->event_reader_pos += ret; if (s->event_reader_pos == sizeof(s->event_acb)) { s->event_reader_pos = 0; qemu_gluster_complete_aio(s->event_acb, s); } } } while (ret < 0 && errno == EINTR); } static int qemu_gluster_aio_flush_cb(void *opaque) { BDRVGlusterState *s = opaque; return (s->qemu_aio_count > 0); } static int qemu_gluster_open(BlockDriverState *bs, const char *filename, int bdrv_flags) { BDRVGlusterState *s = bs->opaque; int open_flags = O_BINARY; int ret = 0; GlusterConf *gconf = g_malloc0(sizeof(GlusterConf)); s->glfs = qemu_gluster_init(gconf, filename); if (!s->glfs) { ret = -errno; goto out; } 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; } s->fd = glfs_open(s->glfs, gconf->image, open_flags); if (!s->fd) { ret = -errno; goto out; } ret = qemu_pipe(s->fds); if (ret < 0) { ret = -errno; goto out; } fcntl(s->fds[GLUSTER_FD_READ], F_SETFL, O_NONBLOCK); qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], qemu_gluster_aio_event_reader, NULL, qemu_gluster_aio_flush_cb, s); out: qemu_gluster_gconf_free(gconf); if (!ret) { return ret; } if (s->fd) { glfs_close(s->fd); } if (s->glfs) { glfs_fini(s->glfs); } return ret; } static int qemu_gluster_create(const char *filename, QEMUOptionParameter *options) { struct glfs *glfs; struct glfs_fd *fd; int ret = 0; int64_t total_size = 0; GlusterConf *gconf = g_malloc0(sizeof(GlusterConf)); glfs = qemu_gluster_init(gconf, filename); if (!glfs) { ret = -errno; goto out; } while (options && options->name) { if (!strcmp(options->name, BLOCK_OPT_SIZE)) { total_size = options->value.n / BDRV_SECTOR_SIZE; } options++; } fd = glfs_creat(glfs, gconf->image, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR); if (!fd) { ret = -errno; } else { if (glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) { ret = -errno; } if (glfs_close(fd) != 0) { ret = -errno; } } out: qemu_gluster_gconf_free(gconf); if (glfs) { glfs_fini(glfs); } return ret; } static void qemu_gluster_aio_cancel(BlockDriverAIOCB *blockacb) { GlusterAIOCB *acb = (GlusterAIOCB *)blockacb; bool finished = false; acb->finished = &finished; while (!finished) { qemu_aio_wait(); } } static const AIOCBInfo gluster_aiocb_info = { .aiocb_size = sizeof(GlusterAIOCB), .cancel = qemu_gluster_aio_cancel, }; static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg) { GlusterAIOCB *acb = (GlusterAIOCB *)arg; BlockDriverState *bs = acb->common.bs; BDRVGlusterState *s = bs->opaque; int retval; acb->ret = ret; retval = qemu_write_full(s->fds[GLUSTER_FD_WRITE], &acb, sizeof(acb)); if (retval != sizeof(acb)) { /* * Gluster AIO callback thread failed to notify the waiting * QEMU thread about IO completion. * * Complete this IO request and make the disk inaccessible for * subsequent reads and writes. */ error_report("Gluster failed to notify QEMU about IO completion"); qemu_mutex_lock_iothread(); /* We are in gluster thread context */ acb->common.cb(acb->common.opaque, -EIO); qemu_aio_release(acb); s->qemu_aio_count--; close(s->fds[GLUSTER_FD_READ]); close(s->fds[GLUSTER_FD_WRITE]); qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL, NULL); bs->drv = NULL; /* Make the disk inaccessible */ qemu_mutex_unlock_iothread(); } } static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque, int write) { int ret; GlusterAIOCB *acb; BDRVGlusterState *s = bs->opaque; size_t size; off_t offset; offset = sector_num * BDRV_SECTOR_SIZE; size = nb_sectors * BDRV_SECTOR_SIZE; s->qemu_aio_count++; acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque); acb->size = size; acb->ret = 0; acb->finished = NULL; 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) { goto out; } return &acb->common; out: s->qemu_aio_count--; qemu_aio_release(acb); return NULL; } static BlockDriverAIOCB *qemu_gluster_aio_readv(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); } static BlockDriverAIOCB *qemu_gluster_aio_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); } static BlockDriverAIOCB *qemu_gluster_aio_flush(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque) { int ret; GlusterAIOCB *acb; BDRVGlusterState *s = bs->opaque; acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque); acb->size = 0; acb->ret = 0; acb->finished = NULL; s->qemu_aio_count++; ret = glfs_fsync_async(s->fd, &gluster_finish_aiocb, acb); if (ret < 0) { goto out; } return &acb->common; out: s->qemu_aio_count--; qemu_aio_release(acb); return NULL; } 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; } } static void qemu_gluster_close(BlockDriverState *bs) { BDRVGlusterState *s = bs->opaque; close(s->fds[GLUSTER_FD_READ]); close(s->fds[GLUSTER_FD_WRITE]); qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL, NULL); if (s->fd) { glfs_close(s->fd); s->fd = NULL; } glfs_fini(s->glfs); } static QEMUOptionParameter qemu_gluster_create_options[] = { { .name = BLOCK_OPT_SIZE, .type = OPT_SIZE, .help = "Virtual disk size" }, { NULL } }; static BlockDriver bdrv_gluster = { .format_name = "gluster", .protocol_name = "gluster", .instance_size = sizeof(BDRVGlusterState), .bdrv_file_open = qemu_gluster_open, .bdrv_close = qemu_gluster_close, .bdrv_create = qemu_gluster_create, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_aio_readv = qemu_gluster_aio_readv, .bdrv_aio_writev = qemu_gluster_aio_writev, .bdrv_aio_flush = qemu_gluster_aio_flush, .create_options = qemu_gluster_create_options, }; static BlockDriver bdrv_gluster_tcp = { .format_name = "gluster", .protocol_name = "gluster+tcp", .instance_size = sizeof(BDRVGlusterState), .bdrv_file_open = qemu_gluster_open, .bdrv_close = qemu_gluster_close, .bdrv_create = qemu_gluster_create, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_aio_readv = qemu_gluster_aio_readv, .bdrv_aio_writev = qemu_gluster_aio_writev, .bdrv_aio_flush = qemu_gluster_aio_flush, .create_options = qemu_gluster_create_options, }; static BlockDriver bdrv_gluster_unix = { .format_name = "gluster", .protocol_name = "gluster+unix", .instance_size = sizeof(BDRVGlusterState), .bdrv_file_open = qemu_gluster_open, .bdrv_close = qemu_gluster_close, .bdrv_create = qemu_gluster_create, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_aio_readv = qemu_gluster_aio_readv, .bdrv_aio_writev = qemu_gluster_aio_writev, .bdrv_aio_flush = qemu_gluster_aio_flush, .create_options = qemu_gluster_create_options, }; static BlockDriver bdrv_gluster_rdma = { .format_name = "gluster", .protocol_name = "gluster+rdma", .instance_size = sizeof(BDRVGlusterState), .bdrv_file_open = qemu_gluster_open, .bdrv_close = qemu_gluster_close, .bdrv_create = qemu_gluster_create, .bdrv_getlength = qemu_gluster_getlength, .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size, .bdrv_aio_readv = qemu_gluster_aio_readv, .bdrv_aio_writev = qemu_gluster_aio_writev, .bdrv_aio_flush = qemu_gluster_aio_flush, .create_options = qemu_gluster_create_options, }; 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);