diff options
author | Christian Brunner <chb@muc.de> | 2010-12-06 20:53:01 +0100 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2010-12-14 15:44:21 +0100 |
commit | f27aaf4b531bc0eb4f3e1f7accf4931cae36db0d (patch) | |
tree | 8208efd05b17d43d518c8235f2321a24f65ecc2b /block/rbd.c | |
parent | 2a81998a1af40cbc13a5ab1030ec7f05d13d742c (diff) | |
download | qemu-f27aaf4b531bc0eb4f3e1f7accf4931cae36db0d.zip qemu-f27aaf4b531bc0eb4f3e1f7accf4931cae36db0d.tar.gz qemu-f27aaf4b531bc0eb4f3e1f7accf4931cae36db0d.tar.bz2 |
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.c | 1059 |
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); |