@@ -9,3 +9,4 @@ block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LIBISCSI) += iscsi.o
block-obj-$(CONFIG_CURL) += curl.o
block-obj-$(CONFIG_RBD) += rbd.o
+block-obj-$(CONFIG_GLUSTERFS) += gluster.o
new file mode 100644
@@ -0,0 +1,623 @@
+/*
+ * GlusterFS backend for QEMU
+ *
+ * (AIO implementation is derived from block/rbd.c)
+ *
+ * Copyright (C) 2012 Bharata B Rao <bharata@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+#include "block_int.h"
+#include <glusterfs/api/glfs.h>
+
+typedef struct GlusterAIOCB {
+ BlockDriverAIOCB common;
+ bool canceled;
+ int64_t size;
+ int ret;
+} GlusterAIOCB;
+
+typedef struct BDRVGlusterState {
+ struct glfs *glfs;
+ int fds[2];
+ struct glfs_fd *fd;
+ int qemu_aio_count;
+} BDRVGlusterState;
+
+#define GLUSTER_FD_READ 0
+#define GLUSTER_FD_WRITE 1
+
+typedef struct GlusterURI {
+ char *server;
+ int port;
+ char *volname;
+ char *image;
+ char *transport;
+} GlusterURI;
+
+static void qemu_gluster_uri_free(GlusterURI *uri)
+{
+ g_free(uri->server);
+ g_free(uri->volname);
+ g_free(uri->image);
+ g_free(uri->transport);
+ g_free(uri);
+}
+
+/*
+ * We don't validate the transport option obtained here but
+ * instead depend on gluster to flag an error.
+ */
+static int parse_transport(GlusterURI *uri, char *transport)
+{
+ char *token, *saveptr;
+ int ret = -EINVAL;
+
+ if (!transport) {
+ uri->transport = g_strdup("socket");
+ ret = 0;
+ goto out;
+ }
+
+ token = strtok_r(transport, "=", &saveptr);
+ if (!token) {
+ goto out;
+ }
+ if (strcmp(token, "transport")) {
+ goto out;
+ }
+ token = strtok_r(NULL, "=", &saveptr);
+ if (!token) {
+ goto out;
+ }
+ uri->transport = g_strdup(token);
+ ret = 0;
+out:
+ return ret;
+}
+
+static int parse_server(GlusterURI *uri, char *server)
+{
+ int ret = -EINVAL;
+ char *token, *saveptr;
+ char *p, *q = server;
+
+ p = strchr(server, '[');
+ if (p) {
+ /* [ipv6] */
+ if (p != server) {
+ /* [ not in the beginning */
+ goto out;
+ }
+ q++;
+ p = strrchr(p, ']');
+ if (!p) {
+ /* No matching ] */
+ goto out;
+ }
+ *p++ = '\0';
+ uri->server = g_strdup(q);
+
+ if (*p) {
+ if (*p != ':') {
+ /* [ipv6] followed by something other than : */
+ goto out;
+ }
+ uri->port = strtoul(++p, NULL, 0);
+ if (uri->port < 0) {
+ goto out;
+ }
+ } else {
+ /* port not specified, use default */
+ uri->port = 0;
+ }
+
+ } else {
+ /* ipv4 or hostname */
+ if (*server == ':') {
+ /* port specified w/o a server */
+ goto out;
+ }
+ token = strtok_r(server, ":", &saveptr);
+ if (!token) {
+ goto out;
+ }
+ uri->server = g_strdup(token);
+ token = strtok_r(NULL, ":", &saveptr);
+ if (token) {
+ uri->port = strtoul(token, NULL, 0);
+ if (uri->port < 0) {
+ goto out;
+ }
+ } else {
+ uri->port = 0;
+ }
+ }
+ ret = 0;
+out:
+ return ret;
+}
+
+/*
+ * file=gluster://server:[port]/volname/image[?transport=socket]
+ *
+ * 'gluster' is the protocol.
+ *
+ * 'server' specifies the server where the volume file specification for
+ * the given volume resides. This can be either hostname or ipv4 address
+ * or ipv6 address. ipv6 address needs to be with in square brackets [ ].
+ *
+ *'port' is the port number on which gluster management daemon (glusterd) is
+ * listening. This is optional and if not specified, QEMU will send 0 which
+ * will make libgfapi to use the default port.
+ *
+ * 'volname' is the name of the gluster volume which contains the VM image.
+ *
+ * 'image' is the path to the actual VM image in the gluster volume.
+ *
+ * 'transport' specifies the transport used to connect to glusterd. This is
+ * optional and if not specified, socket transport is used.
+ *
+ * Examples:
+ *
+ * file=gluster://1.2.3.4/testvol/a.img
+ * file=gluster://1.2.3.4:5000/testvol/dir/a.img?transport=socket
+ * file=gluster://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
+ * file=gluster://[1:2:3:4:5:6:7:8]:5000/testvol/dir/a.img?transport=socket
+ * file=gluster://server.domain.com:5000/testvol/dir/a.img
+ *
+ * We just do minimal checking of the gluster options and mostly ensure
+ * that all the expected elements of the URI are present. We depend on libgfapi
+ * APIs to return appropriate errors in case of invalid arguments.
+ */
+static int qemu_gluster_parseuri(GlusterURI *uri, const char *filename)
+{
+ char *token, *saveptr;
+ char *p, *r;
+ int ret = -EINVAL;
+
+ p = r = g_strdup(filename);
+ if (strncmp(p, "gluster://", 10)) {
+ goto out;
+ }
+
+ /* Discard the protocol */
+ p += 10;
+
+ /* server */
+ token = strtok_r(p, "/", &saveptr);
+ if (!token) {
+ goto out;
+ }
+
+ ret = parse_server(uri, token);
+ if (ret < 0) {
+ goto out;
+ }
+
+ /* volname */
+ token = strtok_r(NULL, "/", &saveptr);
+ if (!token) {
+ ret = -EINVAL;
+ goto out;
+ }
+ uri->volname = g_strdup(token);
+
+ /* image */
+ token = strtok_r(NULL, "?", &saveptr);
+ if (!token) {
+ ret = -EINVAL;
+ goto out;
+ }
+ uri->image = g_strdup(token);
+
+ /* transport */
+ token = strtok_r(NULL, "?", &saveptr);
+ ret = parse_transport(uri, token);
+ if (ret < 0) {
+ goto out;
+ }
+
+ /* Flag error for extra options */
+ token = strtok_r(NULL, "?", &saveptr);
+ if (token) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = 0;
+out:
+ g_free(r);
+ return ret;
+}
+
+static struct glfs *qemu_gluster_init(GlusterURI *uri, const char *filename)
+{
+ struct glfs *glfs = NULL;
+ int ret;
+
+ ret = qemu_gluster_parseuri(uri, filename);
+ if (ret < 0) {
+ error_report("Usage: file=gluster://server:[port]/volname/image"
+ "[?transport=socket]");
+ errno = -ret;
+ goto out;
+ }
+
+ glfs = glfs_new(uri->volname);
+ if (!glfs) {
+ goto out;
+ }
+
+ ret = glfs_set_volfile_server(glfs, uri->transport, uri->server,
+ uri->port);
+ if (ret < 0) {
+ goto out;
+ }
+
+ /*
+ * TODO: Use GF_LOG_ERROR instead of hard code value of 4 here when
+ * GlusterFS exports it in a header.
+ */
+ 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", uri->server, uri->port,
+ uri->volname, uri->image, uri->transport);
+ goto out;
+ }
+ return glfs;
+
+out:
+ if (glfs) {
+ glfs_fini(glfs);
+ }
+ return NULL;
+}
+
+static void qemu_gluster_complete_aio(GlusterAIOCB *acb)
+{
+ int ret;
+
+ if (acb->canceled) {
+ qemu_aio_release(acb);
+ return;
+ }
+
+ if (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 */
+ }
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
+}
+
+static void qemu_gluster_aio_event_reader(void *opaque)
+{
+ BDRVGlusterState *s = opaque;
+ GlusterAIOCB *event_acb;
+ int event_reader_pos = 0;
+ ssize_t ret;
+
+ do {
+ char *p = (char *)&event_acb;
+
+ ret = read(s->fds[GLUSTER_FD_READ], p + event_reader_pos,
+ sizeof(event_acb) - event_reader_pos);
+ if (ret > 0) {
+ event_reader_pos += ret;
+ if (event_reader_pos == sizeof(event_acb)) {
+ event_reader_pos = 0;
+ qemu_gluster_complete_aio(event_acb);
+ s->qemu_aio_count--;
+ }
+ }
+ } 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 = 0;
+ int ret = 0;
+ GlusterURI *uri = g_malloc0(sizeof(GlusterURI));
+
+ s->glfs = qemu_gluster_init(uri, filename);
+ if (!s->glfs) {
+ ret = -errno;
+ goto out;
+ }
+
+ open_flags |= O_BINARY;
+ open_flags &= ~O_ACCMODE;
+ 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, uri->image, open_flags);
+ if (!s->fd) {
+ ret = -errno;
+ goto out;
+ }
+
+ ret = qemu_pipe(s->fds);
+ if (ret < 0) {
+ goto out;
+ }
+ fcntl(s->fds[0], F_SETFL, O_NONBLOCK);
+ fcntl(s->fds[1], 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_uri_free(uri);
+ 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;
+ GlusterURI *uri = g_malloc0(sizeof(GlusterURI));
+
+ glfs = qemu_gluster_init(uri, 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, uri->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_uri_free(uri);
+ if (glfs) {
+ glfs_fini(glfs);
+ }
+ return ret;
+}
+
+static void qemu_gluster_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+ GlusterAIOCB *acb = (GlusterAIOCB *)blockacb;
+
+ acb->common.cb(acb->common.opaque, -ECANCELED);
+ acb->canceled = true;
+}
+
+static AIOPool gluster_aio_pool = {
+ .aiocb_size = sizeof(GlusterAIOCB),
+ .cancel = qemu_gluster_aio_cancel,
+};
+
+static int qemu_gluster_send_pipe(BDRVGlusterState *s, GlusterAIOCB *acb)
+{
+ int ret = 0;
+ while (1) {
+ fd_set wfd;
+ int fd = s->fds[GLUSTER_FD_WRITE];
+
+ ret = write(fd, (void *)&acb, sizeof(acb));
+ if (ret >= 0) {
+ break;
+ }
+ if (errno == EINTR) {
+ continue;
+ }
+ if (errno != EAGAIN) {
+ break;
+ }
+
+ FD_ZERO(&wfd);
+ FD_SET(fd, &wfd);
+ do {
+ ret = select(fd + 1, NULL, &wfd, NULL, NULL);
+ } while (ret < 0 && errno == EINTR);
+ }
+ return ret;
+}
+
+static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
+{
+ GlusterAIOCB *acb = (GlusterAIOCB *)arg;
+ BDRVGlusterState *s = acb->common.bs->opaque;
+
+ acb->ret = ret;
+ if (qemu_gluster_send_pipe(s, acb) < 0) {
+ /*
+ * Gluster AIO callback thread failed to notify the waiting
+ * QEMU thread about IO completion. Nothing much can be done
+ * here but to abruptly abort.
+ *
+ * FIXME: Check if the read side of the fd handler can somehow
+ * be notified of this failure paving the way for a graceful exit.
+ */
+ error_report("Gluster failed to notify QEMU about IO completion");
+ abort();
+ }
+}
+
+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->canceled = false;
+
+ 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->canceled = false;
+ 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;
+ struct stat st;
+ int ret;
+
+ ret = glfs_fstat(s->fd, &st);
+ if (ret < 0) {
+ return -errno;
+ } else {
+ return st.st_size;
+ }
+}
+
+static void qemu_gluster_close(BlockDriverState *bs)
+{
+ BDRVGlusterState *s = bs->opaque;
+
+ 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_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);
+}
+
+block_init(bdrv_gluster_init);