From de573f0f0ccb59d3e2d227edc0508b96ffe4a516 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: <276ddced7c9181cce17d0ff9eb080f99dcfe0ac3.1376492227.git.minovotn@redhat.com> References: <276ddced7c9181cce17d0ff9eb080f99dcfe0ac3.1376492227.git.minovotn@redhat.com> From: Asias He Date: Wed, 14 Aug 2013 10:24:11 +0200 Subject: [PATCH 10/22] block: Support GlusterFS as a QEMU block backend. RH-Author: Asias He Message-id: <1376475863-27929-6-git-send-email-asias@redhat.com> Patchwork-id: 53392 O-Subject: [RHEL6.5 qemu-kvm PATCH v4 05/17] block: Support GlusterFS as a QEMU block backend. Bugzilla: 848070 RH-Acked-by: Kevin Wolf RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Jeffrey Cody From: Bharata B Rao This patch adds gluster as the new block backend in QEMU. This gives QEMU the ability to boot VM images from gluster volumes. Its already possible to boot from VM images on gluster volumes using FUSE mount, but this patchset provides the ability to boot VM images from gluster volumes by by-passing the FUSE layer in gluster. This is made possible by using libgfapi routines to perform IO on gluster volumes directly. VM Image on gluster volume is specified like this: 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 Signed-off-by: Bharata B Rao Signed-off-by: Kevin Wolf (cherry picked from commit 8d6d89cb63c57569864ecdeb84d3a1c2ebd031cc) Conflicts: block/Makefile.objs Make qemu_aio_set_fd_handler args work with RHEL6 --- Makefile.objs | 1 + block/gluster.c | 624 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 625 insertions(+) create mode 100644 block/gluster.c Signed-off-by: Michal Novotny --- Makefile.objs | 1 + block/gluster.c | 624 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 625 insertions(+) create mode 100644 block/gluster.c diff --git a/Makefile.objs b/Makefile.objs index 68fbd22..2e9bdc3 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -31,6 +31,7 @@ block-nested-y += stream.o mirror.o commit.o block-nested-$(CONFIG_WIN32) += raw-win32.o block-nested-$(CONFIG_POSIX) += raw-posix.o block-nested-$(CONFIG_CURL) += curl.o +block-nested-$(CONFIG_GLUSTERFS) += gluster.o block-obj-y += $(addprefix block/, $(block-nested-y)) diff --git a/block/gluster.c b/block/gluster.c new file mode 100644 index 0000000..5163c6b --- /dev/null +++ b/block/gluster.c @@ -0,0 +1,624 @@ +/* + * 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_int.h" +#include "qemu_socket.h" +#include "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, NULL, 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 AIOPool gluster_aio_pool = { + .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, 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_aio_pool, 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_aio_pool, 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, 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); -- 1.7.11.7