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authorChristian Brunner <chb@muc.de>2010-12-06 20:53:01 +0100
committerKevin Wolf <kwolf@redhat.com>2010-12-14 15:44:21 +0100
commitf27aaf4b531bc0eb4f3e1f7accf4931cae36db0d (patch)
tree8208efd05b17d43d518c8235f2321a24f65ecc2b /block/rbd.c
parent2a81998a1af40cbc13a5ab1030ec7f05d13d742c (diff)
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ceph/rbd block driver for qemu-kvm
RBD is an block driver for the distributed file system Ceph (http://ceph.newdream.net/). This driver uses librados (which is part of the Ceph server) for direct access to the Ceph object store and is running entirely in userspace (Yehuda also wrote a driver for the linux kernel, that can be used to access rbd volumes as a block device). Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net> Signed-off-by: Christian Brunner <chb@muc.de> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/rbd.c')
-rw-r--r--block/rbd.c1059
1 files changed, 1059 insertions, 0 deletions
diff --git a/block/rbd.c b/block/rbd.c
new file mode 100644
index 0000000..249a590
--- /dev/null
+++ b/block/rbd.c
@@ -0,0 +1,1059 @@
+/*
+ * QEMU Block driver for RADOS (Ceph)
+ *
+ * Copyright (C) 2010 Christian Brunner <chb@muc.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qemu-error.h"
+
+#include "rbd_types.h"
+#include "block_int.h"
+
+#include <rados/librados.h>
+
+
+
+/*
+ * When specifying the image filename use:
+ *
+ * rbd:poolname/devicename
+ *
+ * poolname must be the name of an existing rados pool
+ *
+ * devicename is the basename for all objects used to
+ * emulate the raw device.
+ *
+ * Metadata information (image size, ...) is stored in an
+ * object with the name "devicename.rbd".
+ *
+ * The raw device is split into 4MB sized objects by default.
+ * The sequencenumber is encoded in a 12 byte long hex-string,
+ * and is attached to the devicename, separated by a dot.
+ * e.g. "devicename.1234567890ab"
+ *
+ */
+
+#define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)
+
+typedef struct RBDAIOCB {
+ BlockDriverAIOCB common;
+ QEMUBH *bh;
+ int ret;
+ QEMUIOVector *qiov;
+ char *bounce;
+ int write;
+ int64_t sector_num;
+ int aiocnt;
+ int error;
+ struct BDRVRBDState *s;
+ int cancelled;
+} RBDAIOCB;
+
+typedef struct RADOSCB {
+ int rcbid;
+ RBDAIOCB *acb;
+ struct BDRVRBDState *s;
+ int done;
+ int64_t segsize;
+ char *buf;
+ int ret;
+} RADOSCB;
+
+#define RBD_FD_READ 0
+#define RBD_FD_WRITE 1
+
+typedef struct BDRVRBDState {
+ int fds[2];
+ rados_pool_t pool;
+ rados_pool_t header_pool;
+ char name[RBD_MAX_OBJ_NAME_SIZE];
+ char block_name[RBD_MAX_BLOCK_NAME_SIZE];
+ uint64_t size;
+ uint64_t objsize;
+ int qemu_aio_count;
+ int event_reader_pos;
+ RADOSCB *event_rcb;
+} BDRVRBDState;
+
+typedef struct rbd_obj_header_ondisk RbdHeader1;
+
+static void rbd_aio_bh_cb(void *opaque);
+
+static int rbd_next_tok(char *dst, int dst_len,
+ char *src, char delim,
+ const char *name,
+ char **p)
+{
+ int l;
+ char *end;
+
+ *p = NULL;
+
+ if (delim != '\0') {
+ end = strchr(src, delim);
+ if (end) {
+ *p = end + 1;
+ *end = '\0';
+ }
+ }
+ l = strlen(src);
+ if (l >= dst_len) {
+ error_report("%s too long", name);
+ return -EINVAL;
+ } else if (l == 0) {
+ error_report("%s too short", name);
+ return -EINVAL;
+ }
+
+ pstrcpy(dst, dst_len, src);
+
+ return 0;
+}
+
+static int rbd_parsename(const char *filename,
+ char *pool, int pool_len,
+ char *snap, int snap_len,
+ char *name, int name_len)
+{
+ const char *start;
+ char *p, *buf;
+ int ret;
+
+ if (!strstart(filename, "rbd:", &start)) {
+ return -EINVAL;
+ }
+
+ buf = qemu_strdup(start);
+ p = buf;
+
+ ret = rbd_next_tok(pool, pool_len, p, '/', "pool name", &p);
+ if (ret < 0 || !p) {
+ ret = -EINVAL;
+ goto done;
+ }
+ ret = rbd_next_tok(name, name_len, p, '@', "object name", &p);
+ if (ret < 0) {
+ goto done;
+ }
+ if (!p) {
+ *snap = '\0';
+ goto done;
+ }
+
+ ret = rbd_next_tok(snap, snap_len, p, '\0', "snap name", &p);
+
+done:
+ qemu_free(buf);
+ return ret;
+}
+
+static int create_tmap_op(uint8_t op, const char *name, char **tmap_desc)
+{
+ uint32_t len = strlen(name);
+ uint32_t len_le = cpu_to_le32(len);
+ /* total_len = encoding op + name + empty buffer */
+ uint32_t total_len = 1 + (sizeof(uint32_t) + len) + sizeof(uint32_t);
+ uint8_t *desc = NULL;
+
+ desc = qemu_malloc(total_len);
+
+ *tmap_desc = (char *)desc;
+
+ *desc = op;
+ desc++;
+ memcpy(desc, &len_le, sizeof(len_le));
+ desc += sizeof(len_le);
+ memcpy(desc, name, len);
+ desc += len;
+ len = 0; /* no need for endian conversion for 0 */
+ memcpy(desc, &len, sizeof(len));
+ desc += sizeof(len);
+
+ return (char *)desc - *tmap_desc;
+}
+
+static void free_tmap_op(char *tmap_desc)
+{
+ qemu_free(tmap_desc);
+}
+
+static int rbd_register_image(rados_pool_t pool, const char *name)
+{
+ char *tmap_desc;
+ const char *dir = RBD_DIRECTORY;
+ int ret;
+
+ ret = create_tmap_op(CEPH_OSD_TMAP_SET, name, &tmap_desc);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = rados_tmap_update(pool, dir, tmap_desc, ret);
+ free_tmap_op(tmap_desc);
+
+ return ret;
+}
+
+static int touch_rbd_info(rados_pool_t pool, const char *info_oid)
+{
+ int r = rados_write(pool, info_oid, 0, NULL, 0);
+ if (r < 0) {
+ return r;
+ }
+ return 0;
+}
+
+static int rbd_assign_bid(rados_pool_t pool, uint64_t *id)
+{
+ uint64_t out[1];
+ const char *info_oid = RBD_INFO;
+
+ *id = 0;
+
+ int r = touch_rbd_info(pool, info_oid);
+ if (r < 0) {
+ return r;
+ }
+
+ r = rados_exec(pool, info_oid, "rbd", "assign_bid", NULL,
+ 0, (char *)out, sizeof(out));
+ if (r < 0) {
+ return r;
+ }
+
+ le64_to_cpus(out);
+ *id = out[0];
+
+ return 0;
+}
+
+static int rbd_create(const char *filename, QEMUOptionParameter *options)
+{
+ int64_t bytes = 0;
+ int64_t objsize;
+ uint64_t size;
+ time_t mtime;
+ uint8_t obj_order = RBD_DEFAULT_OBJ_ORDER;
+ char pool[RBD_MAX_SEG_NAME_SIZE];
+ char n[RBD_MAX_SEG_NAME_SIZE];
+ char name[RBD_MAX_OBJ_NAME_SIZE];
+ char snap_buf[RBD_MAX_SEG_NAME_SIZE];
+ char *snap = NULL;
+ RbdHeader1 header;
+ rados_pool_t p;
+ uint64_t bid;
+ uint32_t hi, lo;
+ int ret;
+
+ if (rbd_parsename(filename,
+ pool, sizeof(pool),
+ snap_buf, sizeof(snap_buf),
+ name, sizeof(name)) < 0) {
+ return -EINVAL;
+ }
+ if (snap_buf[0] != '\0') {
+ snap = snap_buf;
+ }
+
+ snprintf(n, sizeof(n), "%s%s", name, RBD_SUFFIX);
+
+ /* Read out options */
+ while (options && options->name) {
+ if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
+ bytes = options->value.n;
+ } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
+ if (options->value.n) {
+ objsize = options->value.n;
+ if ((objsize - 1) & objsize) { /* not a power of 2? */
+ error_report("obj size needs to be power of 2");
+ return -EINVAL;
+ }
+ if (objsize < 4096) {
+ error_report("obj size too small");
+ return -EINVAL;
+ }
+ obj_order = ffs(objsize) - 1;
+ }
+ }
+ options++;
+ }
+
+ memset(&header, 0, sizeof(header));
+ pstrcpy(header.text, sizeof(header.text), RBD_HEADER_TEXT);
+ pstrcpy(header.signature, sizeof(header.signature), RBD_HEADER_SIGNATURE);
+ pstrcpy(header.version, sizeof(header.version), RBD_HEADER_VERSION);
+ header.image_size = cpu_to_le64(bytes);
+ header.options.order = obj_order;
+ header.options.crypt_type = RBD_CRYPT_NONE;
+ header.options.comp_type = RBD_COMP_NONE;
+ header.snap_seq = 0;
+ header.snap_count = 0;
+
+ if (rados_initialize(0, NULL) < 0) {
+ error_report("error initializing");
+ return -EIO;
+ }
+
+ if (rados_open_pool(pool, &p)) {
+ error_report("error opening pool %s", pool);
+ rados_deinitialize();
+ return -EIO;
+ }
+
+ /* check for existing rbd header file */
+ ret = rados_stat(p, n, &size, &mtime);
+ if (ret == 0) {
+ ret=-EEXIST;
+ goto done;
+ }
+
+ ret = rbd_assign_bid(p, &bid);
+ if (ret < 0) {
+ error_report("failed assigning block id");
+ rados_deinitialize();
+ return -EIO;
+ }
+ hi = bid >> 32;
+ lo = bid & 0xFFFFFFFF;
+ snprintf(header.block_name, sizeof(header.block_name), "rb.%x.%x", hi, lo);
+
+ /* create header file */
+ ret = rados_write(p, n, 0, (const char *)&header, sizeof(header));
+ if (ret < 0) {
+ goto done;
+ }
+
+ ret = rbd_register_image(p, name);
+done:
+ rados_close_pool(p);
+ rados_deinitialize();
+
+ return ret;
+}
+
+/*
+ * This aio completion is being called from rbd_aio_event_reader() and
+ * runs in qemu context. It schedules a bh, but just in case the aio
+ * was not cancelled before.
+ */
+static void rbd_complete_aio(RADOSCB *rcb)
+{
+ RBDAIOCB *acb = rcb->acb;
+ int64_t r;
+
+ acb->aiocnt--;
+
+ if (acb->cancelled) {
+ if (!acb->aiocnt) {
+ qemu_vfree(acb->bounce);
+ qemu_aio_release(acb);
+ }
+ goto done;
+ }
+
+ r = rcb->ret;
+
+ if (acb->write) {
+ if (r < 0) {
+ acb->ret = r;
+ acb->error = 1;
+ } else if (!acb->error) {
+ acb->ret += rcb->segsize;
+ }
+ } else {
+ if (r == -ENOENT) {
+ memset(rcb->buf, 0, rcb->segsize);
+ if (!acb->error) {
+ acb->ret += rcb->segsize;
+ }
+ } else if (r < 0) {
+ memset(rcb->buf, 0, rcb->segsize);
+ acb->ret = r;
+ acb->error = 1;
+ } else if (r < rcb->segsize) {
+ memset(rcb->buf + r, 0, rcb->segsize - r);
+ if (!acb->error) {
+ acb->ret += rcb->segsize;
+ }
+ } else if (!acb->error) {
+ acb->ret += r;
+ }
+ }
+ /* Note that acb->bh can be NULL in case where the aio was cancelled */
+ if (!acb->aiocnt) {
+ acb->bh = qemu_bh_new(rbd_aio_bh_cb, acb);
+ qemu_bh_schedule(acb->bh);
+ }
+done:
+ qemu_free(rcb);
+}
+
+/*
+ * aio fd read handler. It runs in the qemu context and calls the
+ * completion handling of completed rados aio operations.
+ */
+static void rbd_aio_event_reader(void *opaque)
+{
+ BDRVRBDState *s = opaque;
+
+ ssize_t ret;
+
+ do {
+ char *p = (char *)&s->event_rcb;
+
+ /* now read the rcb pointer that was sent from a non qemu thread */
+ if ((ret = read(s->fds[RBD_FD_READ], p + s->event_reader_pos,
+ sizeof(s->event_rcb) - s->event_reader_pos)) > 0) {
+ if (ret > 0) {
+ s->event_reader_pos += ret;
+ if (s->event_reader_pos == sizeof(s->event_rcb)) {
+ s->event_reader_pos = 0;
+ rbd_complete_aio(s->event_rcb);
+ s->qemu_aio_count --;
+ }
+ }
+ }
+ } while (ret < 0 && errno == EINTR);
+}
+
+static int rbd_aio_flush_cb(void *opaque)
+{
+ BDRVRBDState *s = opaque;
+
+ return (s->qemu_aio_count > 0);
+}
+
+
+static int rbd_set_snapc(rados_pool_t pool, const char *snap, RbdHeader1 *header)
+{
+ uint32_t snap_count = le32_to_cpu(header->snap_count);
+ rados_snap_t *snaps = NULL;
+ rados_snap_t seq;
+ uint32_t i;
+ uint64_t snap_names_len = le64_to_cpu(header->snap_names_len);
+ int r;
+ rados_snap_t snapid = 0;
+
+ if (snap_count) {
+ const char *header_snap = (const char *)&header->snaps[snap_count];
+ const char *end = header_snap + snap_names_len;
+ snaps = qemu_malloc(sizeof(rados_snap_t) * header->snap_count);
+
+ for (i=0; i < snap_count; i++) {
+ snaps[i] = le64_to_cpu(header->snaps[i].id);
+
+ if (snap && strcmp(snap, header_snap) == 0) {
+ snapid = snaps[i];
+ }
+
+ header_snap += strlen(header_snap) + 1;
+ if (header_snap > end) {
+ error_report("bad header, snapshot list broken");
+ }
+ }
+ }
+
+ if (snap && !snapid) {
+ error_report("snapshot not found");
+ qemu_free(snaps);
+ return -ENOENT;
+ }
+ seq = le32_to_cpu(header->snap_seq);
+
+ r = rados_set_snap_context(pool, seq, snaps, snap_count);
+
+ rados_set_snap(pool, snapid);
+
+ qemu_free(snaps);
+
+ return r;
+}
+
+#define BUF_READ_START_LEN 4096
+
+static int rbd_read_header(BDRVRBDState *s, char **hbuf)
+{
+ char *buf = NULL;
+ char n[RBD_MAX_SEG_NAME_SIZE];
+ uint64_t len = BUF_READ_START_LEN;
+ int r;
+
+ snprintf(n, sizeof(n), "%s%s", s->name, RBD_SUFFIX);
+
+ buf = qemu_malloc(len);
+
+ r = rados_read(s->header_pool, n, 0, buf, len);
+ if (r < 0) {
+ goto failed;
+ }
+
+ if (r < len) {
+ goto done;
+ }
+
+ qemu_free(buf);
+ buf = qemu_malloc(len);
+
+ r = rados_stat(s->header_pool, n, &len, NULL);
+ if (r < 0) {
+ goto failed;
+ }
+
+ r = rados_read(s->header_pool, n, 0, buf, len);
+ if (r < 0) {
+ goto failed;
+ }
+
+done:
+ *hbuf = buf;
+ return 0;
+
+failed:
+ qemu_free(buf);
+ return r;
+}
+
+static int rbd_open(BlockDriverState *bs, const char *filename, int flags)
+{
+ BDRVRBDState *s = bs->opaque;
+ RbdHeader1 *header;
+ char pool[RBD_MAX_SEG_NAME_SIZE];
+ char snap_buf[RBD_MAX_SEG_NAME_SIZE];
+ char *snap = NULL;
+ char *hbuf = NULL;
+ int r;
+
+ if (rbd_parsename(filename, pool, sizeof(pool),
+ snap_buf, sizeof(snap_buf),
+ s->name, sizeof(s->name)) < 0) {
+ return -EINVAL;
+ }
+ if (snap_buf[0] != '\0') {
+ snap = snap_buf;
+ }
+
+ if ((r = rados_initialize(0, NULL)) < 0) {
+ error_report("error initializing");
+ return r;
+ }
+
+ if ((r = rados_open_pool(pool, &s->pool))) {
+ error_report("error opening pool %s", pool);
+ rados_deinitialize();
+ return r;
+ }
+
+ if ((r = rados_open_pool(pool, &s->header_pool))) {
+ error_report("error opening pool %s", pool);
+ rados_deinitialize();
+ return r;
+ }
+
+ if ((r = rbd_read_header(s, &hbuf)) < 0) {
+ error_report("error reading header from %s", s->name);
+ goto failed;
+ }
+
+ if (memcmp(hbuf + 64, RBD_HEADER_SIGNATURE, 4)) {
+ error_report("Invalid header signature");
+ r = -EMEDIUMTYPE;
+ goto failed;
+ }
+
+ if (memcmp(hbuf + 68, RBD_HEADER_VERSION, 8)) {
+ error_report("Unknown image version");
+ r = -EMEDIUMTYPE;
+ goto failed;
+ }
+
+ header = (RbdHeader1 *) hbuf;
+ s->size = le64_to_cpu(header->image_size);
+ s->objsize = 1ULL << header->options.order;
+ memcpy(s->block_name, header->block_name, sizeof(header->block_name));
+
+ r = rbd_set_snapc(s->pool, snap, header);
+ if (r < 0) {
+ error_report("failed setting snap context: %s", strerror(-r));
+ goto failed;
+ }
+
+ bs->read_only = (snap != NULL);
+
+ s->event_reader_pos = 0;
+ r = qemu_pipe(s->fds);
+ if (r < 0) {
+ error_report("error opening eventfd");
+ goto failed;
+ }
+ fcntl(s->fds[0], F_SETFL, O_NONBLOCK);
+ fcntl(s->fds[1], F_SETFL, O_NONBLOCK);
+ qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], rbd_aio_event_reader, NULL,
+ rbd_aio_flush_cb, NULL, s);
+
+ qemu_free(hbuf);
+
+ return 0;
+
+failed:
+ qemu_free(hbuf);
+
+ rados_close_pool(s->header_pool);
+ rados_close_pool(s->pool);
+ rados_deinitialize();
+ return r;
+}
+
+static void rbd_close(BlockDriverState *bs)
+{
+ BDRVRBDState *s = bs->opaque;
+
+ close(s->fds[0]);
+ close(s->fds[1]);
+ qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], NULL , NULL, NULL, NULL,
+ NULL);
+
+ rados_close_pool(s->header_pool);
+ rados_close_pool(s->pool);
+ rados_deinitialize();
+}
+
+/*
+ * Cancel aio. Since we don't reference acb in a non qemu threads,
+ * it is safe to access it here.
+ */
+static void rbd_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+ RBDAIOCB *acb = (RBDAIOCB *) blockacb;
+ acb->cancelled = 1;
+}
+
+static AIOPool rbd_aio_pool = {
+ .aiocb_size = sizeof(RBDAIOCB),
+ .cancel = rbd_aio_cancel,
+};
+
+/*
+ * This is the callback function for rados_aio_read and _write
+ *
+ * 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
+ * write to the block notification pipe, and do the rest of the
+ * io completion handling from rbd_aio_event_reader() which
+ * runs in a qemu context.
+ */
+static void rbd_finish_aiocb(rados_completion_t c, RADOSCB *rcb)
+{
+ int ret;
+ rcb->ret = rados_aio_get_return_value(c);
+ rados_aio_release(c);
+ while (1) {
+ fd_set wfd;
+ int fd = rcb->s->fds[RBD_FD_WRITE];
+
+ /* send the rcb pointer to the qemu thread that is responsible
+ for the aio completion. Must do it in a qemu thread context */
+ ret = write(fd, (void *)&rcb, sizeof(rcb));
+ 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);
+ }
+
+ if (ret < 0) {
+ error_report("failed writing to acb->s->fds\n");
+ qemu_free(rcb);
+ }
+}
+
+/* Callback when all queued rados_aio requests are complete */
+
+static void rbd_aio_bh_cb(void *opaque)
+{
+ RBDAIOCB *acb = opaque;
+
+ if (!acb->write) {
+ qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
+ }
+ qemu_vfree(acb->bounce);
+ acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
+ qemu_bh_delete(acb->bh);
+ acb->bh = NULL;
+
+ qemu_aio_release(acb);
+}
+
+static BlockDriverAIOCB *rbd_aio_rw_vector(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BlockDriverCompletionFunc *cb,
+ void *opaque, int write)
+{
+ RBDAIOCB *acb;
+ RADOSCB *rcb;
+ rados_completion_t c;
+ char n[RBD_MAX_SEG_NAME_SIZE];
+ int64_t segnr, segoffs, segsize, last_segnr;
+ int64_t off, size;
+ char *buf;
+
+ BDRVRBDState *s = bs->opaque;
+
+ acb = qemu_aio_get(&rbd_aio_pool, bs, cb, opaque);
+ acb->write = write;
+ acb->qiov = qiov;
+ acb->bounce = qemu_blockalign(bs, qiov->size);
+ acb->aiocnt = 0;
+ acb->ret = 0;
+ acb->error = 0;
+ acb->s = s;
+ acb->cancelled = 0;
+ acb->bh = NULL;
+
+ if (write) {
+ qemu_iovec_to_buffer(acb->qiov, acb->bounce);
+ }
+
+ buf = acb->bounce;
+
+ off = sector_num * BDRV_SECTOR_SIZE;
+ size = nb_sectors * BDRV_SECTOR_SIZE;
+ segnr = off / s->objsize;
+ segoffs = off % s->objsize;
+ segsize = s->objsize - segoffs;
+
+ last_segnr = ((off + size - 1) / s->objsize);
+ acb->aiocnt = (last_segnr - segnr) + 1;
+
+ s->qemu_aio_count += acb->aiocnt; /* All the RADOSCB */
+
+ while (size > 0) {
+ if (size < segsize) {
+ segsize = size;
+ }
+
+ snprintf(n, sizeof(n), "%s.%012" PRIx64, s->block_name,
+ segnr);
+
+ rcb = qemu_malloc(sizeof(RADOSCB));
+ rcb->done = 0;
+ rcb->acb = acb;
+ rcb->segsize = segsize;
+ rcb->buf = buf;
+ rcb->s = acb->s;
+
+ if (write) {
+ rados_aio_create_completion(rcb, NULL,
+ (rados_callback_t) rbd_finish_aiocb,
+ &c);
+ rados_aio_write(s->pool, n, segoffs, buf, segsize, c);
+ } else {
+ rados_aio_create_completion(rcb,
+ (rados_callback_t) rbd_finish_aiocb,
+ NULL, &c);
+ rados_aio_read(s->pool, n, segoffs, buf, segsize, c);
+ }
+
+ buf += segsize;
+ size -= segsize;
+ segoffs = 0;
+ segsize = s->objsize;
+ segnr++;
+ }
+
+ return &acb->common;
+}
+
+static BlockDriverAIOCB *rbd_aio_readv(BlockDriverState * bs,
+ int64_t sector_num, QEMUIOVector * qiov,
+ int nb_sectors,
+ BlockDriverCompletionFunc * cb,
+ void *opaque)
+{
+ return rbd_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+}
+
+static BlockDriverAIOCB *rbd_aio_writev(BlockDriverState * bs,
+ int64_t sector_num, QEMUIOVector * qiov,
+ int nb_sectors,
+ BlockDriverCompletionFunc * cb,
+ void *opaque)
+{
+ return rbd_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
+}
+
+static int rbd_getinfo(BlockDriverState * bs, BlockDriverInfo * bdi)
+{
+ BDRVRBDState *s = bs->opaque;
+ bdi->cluster_size = s->objsize;
+ return 0;
+}
+
+static int64_t rbd_getlength(BlockDriverState * bs)
+{
+ BDRVRBDState *s = bs->opaque;
+
+ return s->size;
+}
+
+static int rbd_snap_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
+{
+ BDRVRBDState *s = bs->opaque;
+ char inbuf[512], outbuf[128];
+ uint64_t snap_id;
+ int r;
+ char *p = inbuf;
+ char *end = inbuf + sizeof(inbuf);
+ char n[RBD_MAX_SEG_NAME_SIZE];
+ char *hbuf = NULL;
+ RbdHeader1 *header;
+
+ 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 = rados_selfmanaged_snap_create(s->header_pool, &snap_id);
+ if (r < 0) {
+ error_report("failed to create snap id: %s", strerror(-r));
+ return r;
+ }
+
+ *(uint32_t *)p = strlen(sn_info->name);
+ cpu_to_le32s((uint32_t *)p);
+ p += sizeof(uint32_t);
+ strncpy(p, sn_info->name, end - p);
+ p += strlen(p);
+ if (p + sizeof(snap_id) > end) {
+ error_report("invalid input parameter");
+ return -EINVAL;
+ }
+
+ *(uint64_t *)p = snap_id;
+ cpu_to_le64s((uint64_t *)p);
+
+ snprintf(n, sizeof(n), "%s%s", s->name, RBD_SUFFIX);
+
+ r = rados_exec(s->header_pool, n, "rbd", "snap_add", inbuf,
+ sizeof(inbuf), outbuf, sizeof(outbuf));
+ if (r < 0) {
+ error_report("rbd.snap_add execution failed failed: %s", strerror(-r));
+ return r;
+ }
+
+ sprintf(sn_info->id_str, "%s", sn_info->name);
+
+ r = rbd_read_header(s, &hbuf);
+ if (r < 0) {
+ error_report("failed reading header: %s", strerror(-r));
+ return r;
+ }
+
+ header = (RbdHeader1 *) hbuf;
+ r = rbd_set_snapc(s->pool, sn_info->name, header);
+ if (r < 0) {
+ error_report("failed setting snap context: %s", strerror(-r));
+ goto failed;
+ }
+
+ return 0;
+
+failed:
+ qemu_free(header);
+ return r;
+}
+
+static int decode32(char **p, const char *end, uint32_t *v)
+{
+ if (*p + 4 > end) {
+ return -ERANGE;
+ }
+
+ *v = *(uint32_t *)(*p);
+ le32_to_cpus(v);
+ *p += 4;
+ return 0;
+}
+
+static int decode64(char **p, const char *end, uint64_t *v)
+{
+ if (*p + 8 > end) {
+ return -ERANGE;
+ }
+
+ *v = *(uint64_t *)(*p);
+ le64_to_cpus(v);
+ *p += 8;
+ return 0;
+}
+
+static int decode_str(char **p, const char *end, char **s)
+{
+ uint32_t len;
+ int r;
+
+ if ((r = decode32(p, end, &len)) < 0) {
+ return r;
+ }
+
+ *s = qemu_malloc(len + 1);
+ memcpy(*s, *p, len);
+ *p += len;
+ (*s)[len] = '\0';
+
+ return len;
+}
+
+static int rbd_snap_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
+{
+ BDRVRBDState *s = bs->opaque;
+ char n[RBD_MAX_SEG_NAME_SIZE];
+ QEMUSnapshotInfo *sn_info, *sn_tab = NULL;
+ RbdHeader1 *header;
+ char *hbuf = NULL;
+ char *outbuf = NULL, *end, *buf;
+ uint64_t len;
+ uint64_t snap_seq;
+ uint32_t snap_count;
+ int r, i;
+
+ /* read header to estimate how much space we need to read the snap
+ * list */
+ if ((r = rbd_read_header(s, &hbuf)) < 0) {
+ goto done_err;
+ }
+ header = (RbdHeader1 *)hbuf;
+ len = le64_to_cpu(header->snap_names_len);
+ len += 1024; /* should have already been enough, but new snapshots might
+ already been created since we read the header. just allocate
+ a bit more, so that in most cases it'll suffice anyway */
+ qemu_free(hbuf);
+
+ snprintf(n, sizeof(n), "%s%s", s->name, RBD_SUFFIX);
+ while (1) {
+ qemu_free(outbuf);
+ outbuf = qemu_malloc(len);
+
+ r = rados_exec(s->header_pool, n, "rbd", "snap_list", NULL, 0,
+ outbuf, len);
+ if (r < 0) {
+ error_report("rbd.snap_list execution failed failed: %s", strerror(-r));
+ goto done_err;
+ }
+ if (r != len) {
+ break;
+ }
+
+ /* if we're here, we probably raced with some snaps creation */
+ len *= 2;
+ }
+ buf = outbuf;
+ end = buf + len;
+
+ if ((r = decode64(&buf, end, &snap_seq)) < 0) {
+ goto done_err;
+ }
+ if ((r = decode32(&buf, end, &snap_count)) < 0) {
+ goto done_err;
+ }
+
+ sn_tab = qemu_mallocz(snap_count * sizeof(QEMUSnapshotInfo));
+ for (i = 0; i < snap_count; i++) {
+ uint64_t id, image_size;
+ char *snap_name;
+
+ if ((r = decode64(&buf, end, &id)) < 0) {
+ goto done_err;
+ }
+ if ((r = decode64(&buf, end, &image_size)) < 0) {
+ goto done_err;
+ }
+ if ((r = decode_str(&buf, end, &snap_name)) < 0) {
+ goto done_err;
+ }
+
+ 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);
+ qemu_free(snap_name);
+
+ sn_info->vm_state_size = image_size;
+ sn_info->date_sec = 0;
+ sn_info->date_nsec = 0;
+ sn_info->vm_clock_nsec = 0;
+ }
+ *psn_tab = sn_tab;
+ qemu_free(outbuf);
+ return snap_count;
+done_err:
+ qemu_free(sn_tab);
+ qemu_free(outbuf);
+ return r;
+}
+
+static QEMUOptionParameter rbd_create_options[] = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_CLUSTER_SIZE,
+ .type = OPT_SIZE,
+ .help = "RBD object size"
+ },
+ {NULL}
+};
+
+static BlockDriver bdrv_rbd = {
+ .format_name = "rbd",
+ .instance_size = sizeof(BDRVRBDState),
+ .bdrv_file_open = rbd_open,
+ .bdrv_close = rbd_close,
+ .bdrv_create = rbd_create,
+ .bdrv_get_info = rbd_getinfo,
+ .create_options = rbd_create_options,
+ .bdrv_getlength = rbd_getlength,
+ .protocol_name = "rbd",
+
+ .bdrv_aio_readv = rbd_aio_readv,
+ .bdrv_aio_writev = rbd_aio_writev,
+
+ .bdrv_snapshot_create = rbd_snap_create,
+ .bdrv_snapshot_list = rbd_snap_list,
+};
+
+static void bdrv_rbd_init(void)
+{
+ bdrv_register(&bdrv_rbd);
+}
+
+block_init(bdrv_rbd_init);