/* * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ #include "qemu/osdep.h" #include "qemu-common.h" #include "qapi/error.h" #include "qapi/qapi-visit-sockets.h" #include "qapi/qapi-visit-block-core.h" #include "qapi/qmp/qdict.h" #include "qapi/qobject-input-visitor.h" #include "qapi/qobject-output-visitor.h" #include "qemu/uri.h" #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "qemu/module.h" #include "qemu/option.h" #include "qemu/sockets.h" #include "block/block_int.h" #include "block/qdict.h" #include "sysemu/block-backend.h" #include "qemu/bitops.h" #include "qemu/cutils.h" #include "trace.h" #define SD_PROTO_VER 0x01 #define SD_DEFAULT_ADDR "localhost" #define SD_DEFAULT_PORT 7000 #define SD_OP_CREATE_AND_WRITE_OBJ 0x01 #define SD_OP_READ_OBJ 0x02 #define SD_OP_WRITE_OBJ 0x03 /* 0x04 is used internally by Sheepdog */ #define SD_OP_NEW_VDI 0x11 #define SD_OP_LOCK_VDI 0x12 #define SD_OP_RELEASE_VDI 0x13 #define SD_OP_GET_VDI_INFO 0x14 #define SD_OP_READ_VDIS 0x15 #define SD_OP_FLUSH_VDI 0x16 #define SD_OP_DEL_VDI 0x17 #define SD_OP_GET_CLUSTER_DEFAULT 0x18 #define SD_FLAG_CMD_WRITE 0x01 #define SD_FLAG_CMD_COW 0x02 #define SD_FLAG_CMD_CACHE 0x04 /* Writeback mode for cache */ #define SD_FLAG_CMD_DIRECT 0x08 /* Don't use cache */ #define SD_RES_SUCCESS 0x00 /* Success */ #define SD_RES_UNKNOWN 0x01 /* Unknown error */ #define SD_RES_NO_OBJ 0x02 /* No object found */ #define SD_RES_EIO 0x03 /* I/O error */ #define SD_RES_VDI_EXIST 0x04 /* Vdi exists already */ #define SD_RES_INVALID_PARMS 0x05 /* Invalid parameters */ #define SD_RES_SYSTEM_ERROR 0x06 /* System error */ #define SD_RES_VDI_LOCKED 0x07 /* Vdi is locked */ #define SD_RES_NO_VDI 0x08 /* No vdi found */ #define SD_RES_NO_BASE_VDI 0x09 /* No base vdi found */ #define SD_RES_VDI_READ 0x0A /* Cannot read requested vdi */ #define SD_RES_VDI_WRITE 0x0B /* Cannot write requested vdi */ #define SD_RES_BASE_VDI_READ 0x0C /* Cannot read base vdi */ #define SD_RES_BASE_VDI_WRITE 0x0D /* Cannot write base vdi */ #define SD_RES_NO_TAG 0x0E /* Requested tag is not found */ #define SD_RES_STARTUP 0x0F /* Sheepdog is on starting up */ #define SD_RES_VDI_NOT_LOCKED 0x10 /* Vdi is not locked */ #define SD_RES_SHUTDOWN 0x11 /* Sheepdog is shutting down */ #define SD_RES_NO_MEM 0x12 /* Cannot allocate memory */ #define SD_RES_FULL_VDI 0x13 /* we already have the maximum vdis */ #define SD_RES_VER_MISMATCH 0x14 /* Protocol version mismatch */ #define SD_RES_NO_SPACE 0x15 /* Server has no room for new objects */ #define SD_RES_WAIT_FOR_FORMAT 0x16 /* Waiting for a format operation */ #define SD_RES_WAIT_FOR_JOIN 0x17 /* Waiting for other nodes joining */ #define SD_RES_JOIN_FAILED 0x18 /* Target node had failed to join sheepdog */ #define SD_RES_HALT 0x19 /* Sheepdog is stopped serving IO request */ #define SD_RES_READONLY 0x1A /* Object is read-only */ /* * Object ID rules * * 0 - 19 (20 bits): data object space * 20 - 31 (12 bits): reserved data object space * 32 - 55 (24 bits): vdi object space * 56 - 59 ( 4 bits): reserved vdi object space * 60 - 63 ( 4 bits): object type identifier space */ #define VDI_SPACE_SHIFT 32 #define VDI_BIT (UINT64_C(1) << 63) #define VMSTATE_BIT (UINT64_C(1) << 62) #define MAX_DATA_OBJS (UINT64_C(1) << 20) #define MAX_CHILDREN 1024 #define SD_MAX_VDI_LEN 256 #define SD_MAX_VDI_TAG_LEN 256 #define SD_NR_VDIS (1U << 24) #define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22) #define SD_MAX_VDI_SIZE (SD_DATA_OBJ_SIZE * MAX_DATA_OBJS) #define SD_DEFAULT_BLOCK_SIZE_SHIFT 22 /* * For erasure coding, we use at most SD_EC_MAX_STRIP for data strips and * (SD_EC_MAX_STRIP - 1) for parity strips * * SD_MAX_COPIES is sum of number of data strips and parity strips. */ #define SD_EC_MAX_STRIP 16 #define SD_MAX_COPIES (SD_EC_MAX_STRIP * 2 - 1) #define SD_INODE_SIZE (sizeof(SheepdogInode)) #define CURRENT_VDI_ID 0 #define LOCK_TYPE_NORMAL 0 #define LOCK_TYPE_SHARED 1 /* for iSCSI multipath */ typedef struct SheepdogReq { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint32_t opcode_specific[8]; } SheepdogReq; typedef struct SheepdogRsp { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint32_t result; uint32_t opcode_specific[7]; } SheepdogRsp; typedef struct SheepdogObjReq { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint64_t oid; uint64_t cow_oid; uint8_t copies; uint8_t copy_policy; uint8_t reserved[6]; uint64_t offset; } SheepdogObjReq; typedef struct SheepdogObjRsp { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint32_t result; uint8_t copies; uint8_t copy_policy; uint8_t reserved[2]; uint32_t pad[6]; } SheepdogObjRsp; typedef struct SheepdogVdiReq { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint64_t vdi_size; uint32_t base_vdi_id; uint8_t copies; uint8_t copy_policy; uint8_t store_policy; uint8_t block_size_shift; uint32_t snapid; uint32_t type; uint32_t pad[2]; } SheepdogVdiReq; typedef struct SheepdogVdiRsp { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint32_t result; uint32_t rsvd; uint32_t vdi_id; uint32_t pad[5]; } SheepdogVdiRsp; typedef struct SheepdogClusterRsp { uint8_t proto_ver; uint8_t opcode; uint16_t flags; uint32_t epoch; uint32_t id; uint32_t data_length; uint32_t result; uint8_t nr_copies; uint8_t copy_policy; uint8_t block_size_shift; uint8_t __pad1; uint32_t __pad2[6]; } SheepdogClusterRsp; typedef struct SheepdogInode { char name[SD_MAX_VDI_LEN]; char tag[SD_MAX_VDI_TAG_LEN]; uint64_t ctime; uint64_t snap_ctime; uint64_t vm_clock_nsec; uint64_t vdi_size; uint64_t vm_state_size; uint16_t copy_policy; uint8_t nr_copies; uint8_t block_size_shift; uint32_t snap_id; uint32_t vdi_id; uint32_t parent_vdi_id; uint32_t child_vdi_id[MAX_CHILDREN]; uint32_t data_vdi_id[MAX_DATA_OBJS]; } SheepdogInode; #define SD_INODE_HEADER_SIZE offsetof(SheepdogInode, data_vdi_id) /* * 64 bit FNV-1a non-zero initial basis */ #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL) /* * 64 bit Fowler/Noll/Vo FNV-1a hash code */ static inline uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval) { unsigned char *bp = buf; unsigned char *be = bp + len; while (bp < be) { hval ^= (uint64_t) *bp++; hval += (hval << 1) + (hval << 4) + (hval << 5) + (hval << 7) + (hval << 8) + (hval << 40); } return hval; } static inline bool is_data_obj_writable(SheepdogInode *inode, unsigned int idx) { return inode->vdi_id == inode->data_vdi_id[idx]; } static inline bool is_data_obj(uint64_t oid) { return !(VDI_BIT & oid); } static inline uint64_t data_oid_to_idx(uint64_t oid) { return oid & (MAX_DATA_OBJS - 1); } static inline uint32_t oid_to_vid(uint64_t oid) { return (oid & ~VDI_BIT) >> VDI_SPACE_SHIFT; } static inline uint64_t vid_to_vdi_oid(uint32_t vid) { return VDI_BIT | ((uint64_t)vid << VDI_SPACE_SHIFT); } static inline uint64_t vid_to_vmstate_oid(uint32_t vid, uint32_t idx) { return VMSTATE_BIT | ((uint64_t)vid << VDI_SPACE_SHIFT) | idx; } static inline uint64_t vid_to_data_oid(uint32_t vid, uint32_t idx) { return ((uint64_t)vid << VDI_SPACE_SHIFT) | idx; } static inline bool is_snapshot(struct SheepdogInode *inode) { return !!inode->snap_ctime; } static inline size_t count_data_objs(const struct SheepdogInode *inode) { return DIV_ROUND_UP(inode->vdi_size, (1UL << inode->block_size_shift)); } typedef struct SheepdogAIOCB SheepdogAIOCB; typedef struct BDRVSheepdogState BDRVSheepdogState; typedef struct AIOReq { SheepdogAIOCB *aiocb; unsigned int iov_offset; uint64_t oid; uint64_t base_oid; uint64_t offset; unsigned int data_len; uint8_t flags; uint32_t id; bool create; QLIST_ENTRY(AIOReq) aio_siblings; } AIOReq; enum AIOCBState { AIOCB_WRITE_UDATA, AIOCB_READ_UDATA, AIOCB_FLUSH_CACHE, AIOCB_DISCARD_OBJ, }; #define AIOCBOverlapping(x, y) \ (!(x->max_affect_data_idx < y->min_affect_data_idx \ || y->max_affect_data_idx < x->min_affect_data_idx)) struct SheepdogAIOCB { BDRVSheepdogState *s; QEMUIOVector *qiov; int64_t sector_num; int nb_sectors; int ret; enum AIOCBState aiocb_type; Coroutine *coroutine; int nr_pending; uint32_t min_affect_data_idx; uint32_t max_affect_data_idx; /* * The difference between affect_data_idx and dirty_data_idx: * affect_data_idx represents range of index of all request types. * dirty_data_idx represents range of index updated by COW requests. * dirty_data_idx is used for updating an inode object. */ uint32_t min_dirty_data_idx; uint32_t max_dirty_data_idx; QLIST_ENTRY(SheepdogAIOCB) aiocb_siblings; }; struct BDRVSheepdogState { BlockDriverState *bs; AioContext *aio_context; SheepdogInode inode; char name[SD_MAX_VDI_LEN]; bool is_snapshot; uint32_t cache_flags; bool discard_supported; SocketAddress *addr; int fd; CoMutex lock; Coroutine *co_send; Coroutine *co_recv; uint32_t aioreq_seq_num; /* Every aio request must be linked to either of these queues. */ QLIST_HEAD(, AIOReq) inflight_aio_head; QLIST_HEAD(, AIOReq) failed_aio_head; CoMutex queue_lock; CoQueue overlapping_queue; QLIST_HEAD(, SheepdogAIOCB) inflight_aiocb_head; }; typedef struct BDRVSheepdogReopenState { int fd; int cache_flags; } BDRVSheepdogReopenState; static const char *sd_strerror(int err) { int i; static const struct { int err; const char *desc; } errors[] = { {SD_RES_SUCCESS, "Success"}, {SD_RES_UNKNOWN, "Unknown error"}, {SD_RES_NO_OBJ, "No object found"}, {SD_RES_EIO, "I/O error"}, {SD_RES_VDI_EXIST, "VDI exists already"}, {SD_RES_INVALID_PARMS, "Invalid parameters"}, {SD_RES_SYSTEM_ERROR, "System error"}, {SD_RES_VDI_LOCKED, "VDI is already locked"}, {SD_RES_NO_VDI, "No vdi found"}, {SD_RES_NO_BASE_VDI, "No base VDI found"}, {SD_RES_VDI_READ, "Failed read the requested VDI"}, {SD_RES_VDI_WRITE, "Failed to write the requested VDI"}, {SD_RES_BASE_VDI_READ, "Failed to read the base VDI"}, {SD_RES_BASE_VDI_WRITE, "Failed to write the base VDI"}, {SD_RES_NO_TAG, "Failed to find the requested tag"}, {SD_RES_STARTUP, "The system is still booting"}, {SD_RES_VDI_NOT_LOCKED, "VDI isn't locked"}, {SD_RES_SHUTDOWN, "The system is shutting down"}, {SD_RES_NO_MEM, "Out of memory on the server"}, {SD_RES_FULL_VDI, "We already have the maximum vdis"}, {SD_RES_VER_MISMATCH, "Protocol version mismatch"}, {SD_RES_NO_SPACE, "Server has no space for new objects"}, {SD_RES_WAIT_FOR_FORMAT, "Sheepdog is waiting for a format operation"}, {SD_RES_WAIT_FOR_JOIN, "Sheepdog is waiting for other nodes joining"}, {SD_RES_JOIN_FAILED, "Target node had failed to join sheepdog"}, {SD_RES_HALT, "Sheepdog is stopped serving IO request"}, {SD_RES_READONLY, "Object is read-only"}, }; for (i = 0; i < ARRAY_SIZE(errors); ++i) { if (errors[i].err == err) { return errors[i].desc; } } return "Invalid error code"; } /* * Sheepdog I/O handling: * * 1. In sd_co_rw_vector, we send the I/O requests to the server and * link the requests to the inflight_list in the * BDRVSheepdogState. The function yields while waiting for * receiving the response. * * 2. We receive the response in aio_read_response, the fd handler to * the sheepdog connection. We switch back to sd_co_readv/sd_writev * after all the requests belonging to the AIOCB are finished. If * needed, sd_co_writev will send another requests for the vdi object. */ static inline AIOReq *alloc_aio_req(BDRVSheepdogState *s, SheepdogAIOCB *acb, uint64_t oid, unsigned int data_len, uint64_t offset, uint8_t flags, bool create, uint64_t base_oid, unsigned int iov_offset) { AIOReq *aio_req; aio_req = g_malloc(sizeof(*aio_req)); aio_req->aiocb = acb; aio_req->iov_offset = iov_offset; aio_req->oid = oid; aio_req->base_oid = base_oid; aio_req->offset = offset; aio_req->data_len = data_len; aio_req->flags = flags; aio_req->id = s->aioreq_seq_num++; aio_req->create = create; acb->nr_pending++; return aio_req; } static void wait_for_overlapping_aiocb(BDRVSheepdogState *s, SheepdogAIOCB *acb) { SheepdogAIOCB *cb; retry: QLIST_FOREACH(cb, &s->inflight_aiocb_head, aiocb_siblings) { if (AIOCBOverlapping(acb, cb)) { qemu_co_queue_wait(&s->overlapping_queue, &s->queue_lock); goto retry; } } } static void sd_aio_setup(SheepdogAIOCB *acb, BDRVSheepdogState *s, QEMUIOVector *qiov, int64_t sector_num, int nb_sectors, int type) { uint32_t object_size; object_size = (UINT32_C(1) << s->inode.block_size_shift); acb->s = s; acb->qiov = qiov; acb->sector_num = sector_num; acb->nb_sectors = nb_sectors; acb->coroutine = qemu_coroutine_self(); acb->ret = 0; acb->nr_pending = 0; acb->min_affect_data_idx = acb->sector_num * BDRV_SECTOR_SIZE / object_size; acb->max_affect_data_idx = (acb->sector_num * BDRV_SECTOR_SIZE + acb->nb_sectors * BDRV_SECTOR_SIZE) / object_size; acb->min_dirty_data_idx = UINT32_MAX; acb->max_dirty_data_idx = 0; acb->aiocb_type = type; if (type == AIOCB_FLUSH_CACHE) { return; } qemu_co_mutex_lock(&s->queue_lock); wait_for_overlapping_aiocb(s, acb); QLIST_INSERT_HEAD(&s->inflight_aiocb_head, acb, aiocb_siblings); qemu_co_mutex_unlock(&s->queue_lock); } static SocketAddress *sd_server_config(QDict *options, Error **errp) { QDict *server = NULL; Visitor *iv = NULL; SocketAddress *saddr = NULL; Error *local_err = NULL; qdict_extract_subqdict(options, &server, "server."); iv = qobject_input_visitor_new_flat_confused(server, errp); if (!iv) { goto done; } visit_type_SocketAddress(iv, NULL, &saddr, &local_err); if (local_err) { error_propagate(errp, local_err); goto done; } done: visit_free(iv); qobject_unref(server); return saddr; } /* Return -EIO in case of error, file descriptor on success */ static int connect_to_sdog(BDRVSheepdogState *s, Error **errp) { int fd; fd = socket_connect(s->addr, errp); if (s->addr->type == SOCKET_ADDRESS_TYPE_INET && fd >= 0) { int ret = socket_set_nodelay(fd); if (ret < 0) { warn_report("can't set TCP_NODELAY: %s", strerror(errno)); } } if (fd >= 0) { qemu_set_nonblock(fd); } else { fd = -EIO; } return fd; } /* Return 0 on success and -errno in case of error */ static coroutine_fn int send_co_req(int sockfd, SheepdogReq *hdr, void *data, unsigned int *wlen) { int ret; ret = qemu_co_send(sockfd, hdr, sizeof(*hdr)); if (ret != sizeof(*hdr)) { error_report("failed to send a req, %s", strerror(errno)); return -errno; } ret = qemu_co_send(sockfd, data, *wlen); if (ret != *wlen) { error_report("failed to send a req, %s", strerror(errno)); return -errno; } return ret; } typedef struct SheepdogReqCo { int sockfd; BlockDriverState *bs; AioContext *aio_context; SheepdogReq *hdr; void *data; unsigned int *wlen; unsigned int *rlen; int ret; bool finished; Coroutine *co; } SheepdogReqCo; static void restart_co_req(void *opaque) { SheepdogReqCo *srco = opaque; aio_co_wake(srco->co); } static coroutine_fn void do_co_req(void *opaque) { int ret; SheepdogReqCo *srco = opaque; int sockfd = srco->sockfd; SheepdogReq *hdr = srco->hdr; void *data = srco->data; unsigned int *wlen = srco->wlen; unsigned int *rlen = srco->rlen; srco->co = qemu_coroutine_self(); aio_set_fd_handler(srco->aio_context, sockfd, false, NULL, restart_co_req, NULL, srco); ret = send_co_req(sockfd, hdr, data, wlen); if (ret < 0) { goto out; } aio_set_fd_handler(srco->aio_context, sockfd, false, restart_co_req, NULL, NULL, srco); ret = qemu_co_recv(sockfd, hdr, sizeof(*hdr)); if (ret != sizeof(*hdr)) { error_report("failed to get a rsp, %s", strerror(errno)); ret = -errno; goto out; } if (*rlen > hdr->data_length) { *rlen = hdr->data_length; } if (*rlen) { ret = qemu_co_recv(sockfd, data, *rlen); if (ret != *rlen) { error_report("failed to get the data, %s", strerror(errno)); ret = -errno; goto out; } } ret = 0; out: /* there is at most one request for this sockfd, so it is safe to * set each handler to NULL. */ aio_set_fd_handler(srco->aio_context, sockfd, false, NULL, NULL, NULL, NULL); srco->co = NULL; srco->ret = ret; /* Set srco->finished before reading bs->wakeup. */ atomic_mb_set(&srco->finished, true); if (srco->bs) { bdrv_wakeup(srco->bs); } } /* * Send the request to the sheep in a synchronous manner. * * Return 0 on success, -errno in case of error. */ static int do_req(int sockfd, BlockDriverState *bs, SheepdogReq *hdr, void *data, unsigned int *wlen, unsigned int *rlen) { Coroutine *co; SheepdogReqCo srco = { .sockfd = sockfd, .aio_context = bs ? bdrv_get_aio_context(bs) : qemu_get_aio_context(), .bs = bs, .hdr = hdr, .data = data, .wlen = wlen, .rlen = rlen, .ret = 0, .finished = false, }; if (qemu_in_coroutine()) { do_co_req(&srco); } else { co = qemu_coroutine_create(do_co_req, &srco); if (bs) { bdrv_coroutine_enter(bs, co); BDRV_POLL_WHILE(bs, !srco.finished); } else { qemu_coroutine_enter(co); while (!srco.finished) { aio_poll(qemu_get_aio_context(), true); } } } return srco.ret; } static void coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, struct iovec *iov, int niov, enum AIOCBState aiocb_type); static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req); static int reload_inode(BDRVSheepdogState *s, uint32_t snapid, const char *tag); static int get_sheep_fd(BDRVSheepdogState *s, Error **errp); static void co_write_request(void *opaque); static coroutine_fn void reconnect_to_sdog(void *opaque) { BDRVSheepdogState *s = opaque; AIOReq *aio_req, *next; aio_set_fd_handler(s->aio_context, s->fd, false, NULL, NULL, NULL, NULL); close(s->fd); s->fd = -1; /* Wait for outstanding write requests to be completed. */ while (s->co_send != NULL) { co_write_request(opaque); } /* Try to reconnect the sheepdog server every one second. */ while (s->fd < 0) { Error *local_err = NULL; s->fd = get_sheep_fd(s, &local_err); if (s->fd < 0) { trace_sheepdog_reconnect_to_sdog(); error_report_err(local_err); qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000000ULL); } }; /* * Now we have to resend all the request in the inflight queue. However, * resend_aioreq() can yield and newly created requests can be added to the * inflight queue before the coroutine is resumed. To avoid mixing them, we * have to move all the inflight requests to the failed queue before * resend_aioreq() is called. */ qemu_co_mutex_lock(&s->queue_lock); QLIST_FOREACH_SAFE(aio_req, &s->inflight_aio_head, aio_siblings, next) { QLIST_REMOVE(aio_req, aio_siblings); QLIST_INSERT_HEAD(&s->failed_aio_head, aio_req, aio_siblings); } /* Resend all the failed aio requests. */ while (!QLIST_EMPTY(&s->failed_aio_head)) { aio_req = QLIST_FIRST(&s->failed_aio_head); QLIST_REMOVE(aio_req, aio_siblings); qemu_co_mutex_unlock(&s->queue_lock); resend_aioreq(s, aio_req); qemu_co_mutex_lock(&s->queue_lock); } qemu_co_mutex_unlock(&s->queue_lock); } /* * Receive responses of the I/O requests. * * This function is registered as a fd handler, and called from the * main loop when s->fd is ready for reading responses. */ static void coroutine_fn aio_read_response(void *opaque) { SheepdogObjRsp rsp; BDRVSheepdogState *s = opaque; int fd = s->fd; int ret; AIOReq *aio_req = NULL; SheepdogAIOCB *acb; uint64_t idx; /* read a header */ ret = qemu_co_recv(fd, &rsp, sizeof(rsp)); if (ret != sizeof(rsp)) { error_report("failed to get the header, %s", strerror(errno)); goto err; } /* find the right aio_req from the inflight aio list */ QLIST_FOREACH(aio_req, &s->inflight_aio_head, aio_siblings) { if (aio_req->id == rsp.id) { break; } } if (!aio_req) { error_report("cannot find aio_req %x", rsp.id); goto err; } acb = aio_req->aiocb; switch (acb->aiocb_type) { case AIOCB_WRITE_UDATA: if (!is_data_obj(aio_req->oid)) { break; } idx = data_oid_to_idx(aio_req->oid); if (aio_req->create) { /* * If the object is newly created one, we need to update * the vdi object (metadata object). min_dirty_data_idx * and max_dirty_data_idx are changed to include updated * index between them. */ if (rsp.result == SD_RES_SUCCESS) { s->inode.data_vdi_id[idx] = s->inode.vdi_id; acb->max_dirty_data_idx = MAX(idx, acb->max_dirty_data_idx); acb->min_dirty_data_idx = MIN(idx, acb->min_dirty_data_idx); } } break; case AIOCB_READ_UDATA: ret = qemu_co_recvv(fd, acb->qiov->iov, acb->qiov->niov, aio_req->iov_offset, rsp.data_length); if (ret != rsp.data_length) { error_report("failed to get the data, %s", strerror(errno)); goto err; } break; case AIOCB_FLUSH_CACHE: if (rsp.result == SD_RES_INVALID_PARMS) { trace_sheepdog_aio_read_response(); s->cache_flags = SD_FLAG_CMD_DIRECT; rsp.result = SD_RES_SUCCESS; } break; case AIOCB_DISCARD_OBJ: switch (rsp.result) { case SD_RES_INVALID_PARMS: error_report("server doesn't support discard command"); rsp.result = SD_RES_SUCCESS; s->discard_supported = false; break; default: break; } } /* No more data for this aio_req (reload_inode below uses its own file * descriptor handler which doesn't use co_recv). */ s->co_recv = NULL; qemu_co_mutex_lock(&s->queue_lock); QLIST_REMOVE(aio_req, aio_siblings); qemu_co_mutex_unlock(&s->queue_lock); switch (rsp.result) { case SD_RES_SUCCESS: break; case SD_RES_READONLY: if (s->inode.vdi_id == oid_to_vid(aio_req->oid)) { ret = reload_inode(s, 0, ""); if (ret < 0) { goto err; } } if (is_data_obj(aio_req->oid)) { aio_req->oid = vid_to_data_oid(s->inode.vdi_id, data_oid_to_idx(aio_req->oid)); } else { aio_req->oid = vid_to_vdi_oid(s->inode.vdi_id); } resend_aioreq(s, aio_req); return; default: acb->ret = -EIO; error_report("%s", sd_strerror(rsp.result)); break; } g_free(aio_req); if (!--acb->nr_pending) { /* * We've finished all requests which belong to the AIOCB, so * we can switch back to sd_co_readv/writev now. */ aio_co_wake(acb->coroutine); } return; err: reconnect_to_sdog(opaque); } static void co_read_response(void *opaque) { BDRVSheepdogState *s = opaque; if (!s->co_recv) { s->co_recv = qemu_coroutine_create(aio_read_response, opaque); } aio_co_enter(s->aio_context, s->co_recv); } static void co_write_request(void *opaque) { BDRVSheepdogState *s = opaque; aio_co_wake(s->co_send); } /* * Return a socket descriptor to read/write objects. * * We cannot use this descriptor for other operations because * the block driver may be on waiting response from the server. */ static int get_sheep_fd(BDRVSheepdogState *s, Error **errp) { int fd; fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } aio_set_fd_handler(s->aio_context, fd, false, co_read_response, NULL, NULL, s); return fd; } /* * Parse numeric snapshot ID in @str * If @str can't be parsed as number, return false. * Else, if the number is zero or too large, set *@snapid to zero and * return true. * Else, set *@snapid to the number and return true. */ static bool sd_parse_snapid(const char *str, uint32_t *snapid) { unsigned long ul; int ret; ret = qemu_strtoul(str, NULL, 10, &ul); if (ret == -ERANGE) { ul = ret = 0; } if (ret) { return false; } if (ul > UINT32_MAX) { ul = 0; } *snapid = ul; return true; } static bool sd_parse_snapid_or_tag(const char *str, uint32_t *snapid, char tag[]) { if (!sd_parse_snapid(str, snapid)) { *snapid = 0; if (g_strlcpy(tag, str, SD_MAX_VDI_TAG_LEN) >= SD_MAX_VDI_TAG_LEN) { return false; } } else if (!*snapid) { return false; } else { tag[0] = 0; } return true; } typedef struct { const char *path; /* non-null iff transport is tcp */ const char *host; /* valid when transport is tcp */ int port; /* valid when transport is tcp */ char vdi[SD_MAX_VDI_LEN]; char tag[SD_MAX_VDI_TAG_LEN]; uint32_t snap_id; /* Remainder is only for sd_config_done() */ URI *uri; QueryParams *qp; } SheepdogConfig; static void sd_config_done(SheepdogConfig *cfg) { if (cfg->qp) { query_params_free(cfg->qp); } uri_free(cfg->uri); } static void sd_parse_uri(SheepdogConfig *cfg, const char *filename, Error **errp) { Error *err = NULL; QueryParams *qp = NULL; bool is_unix; URI *uri; memset(cfg, 0, sizeof(*cfg)); cfg->uri = uri = uri_parse(filename); if (!uri) { error_setg(&err, "invalid URI '%s'", filename); goto out; } /* transport */ if (!g_strcmp0(uri->scheme, "sheepdog")) { is_unix = false; } else if (!g_strcmp0(uri->scheme, "sheepdog+tcp")) { is_unix = false; } else if (!g_strcmp0(uri->scheme, "sheepdog+unix")) { is_unix = true; } else { error_setg(&err, "URI scheme must be 'sheepdog', 'sheepdog+tcp'," " or 'sheepdog+unix'"); goto out; } if (uri->path == NULL || !strcmp(uri->path, "/")) { error_setg(&err, "missing file path in URI"); goto out; } if (g_strlcpy(cfg->vdi, uri->path + 1, SD_MAX_VDI_LEN) >= SD_MAX_VDI_LEN) { error_setg(&err, "VDI name is too long"); goto out; } cfg->qp = qp = query_params_parse(uri->query); if (is_unix) { /* sheepdog+unix:///vdiname?socket=path */ if (uri->server || uri->port) { error_setg(&err, "URI scheme %s doesn't accept a server address", uri->scheme); goto out; } if (!qp->n) { error_setg(&err, "URI scheme %s requires query parameter 'socket'", uri->scheme); goto out; } if (qp->n != 1 || strcmp(qp->p[0].name, "socket")) { error_setg(&err, "unexpected query parameters"); goto out; } cfg->path = qp->p[0].value; } else { /* sheepdog[+tcp]://[host:port]/vdiname */ if (qp->n) { error_setg(&err, "unexpected query parameters"); goto out; } cfg->host = uri->server; cfg->port = uri->port; } /* snapshot tag */ if (uri->fragment) { if (!sd_parse_snapid_or_tag(uri->fragment, &cfg->snap_id, cfg->tag)) { error_setg(&err, "'%s' is not a valid snapshot ID", uri->fragment); goto out; } } else { cfg->snap_id = CURRENT_VDI_ID; /* search current vdi */ } out: if (err) { error_propagate(errp, err); sd_config_done(cfg); } } /* * Parse a filename (old syntax) * * filename must be one of the following formats: * 1. [vdiname] * 2. [vdiname]:[snapid] * 3. [vdiname]:[tag] * 4. [hostname]:[port]:[vdiname] * 5. [hostname]:[port]:[vdiname]:[snapid] * 6. [hostname]:[port]:[vdiname]:[tag] * * You can boot from the snapshot images by specifying `snapid` or * `tag'. * * You can run VMs outside the Sheepdog cluster by specifying * `hostname' and `port' (experimental). */ static void parse_vdiname(SheepdogConfig *cfg, const char *filename, Error **errp) { Error *err = NULL; char *p, *q, *uri; const char *host_spec, *vdi_spec; int nr_sep; strstart(filename, "sheepdog:", &filename); p = q = g_strdup(filename); /* count the number of separators */ nr_sep = 0; while (*p) { if (*p == ':') { nr_sep++; } p++; } p = q; /* use the first two tokens as host_spec. */ if (nr_sep >= 2) { host_spec = p; p = strchr(p, ':'); p++; p = strchr(p, ':'); *p++ = '\0'; } else { host_spec = ""; } vdi_spec = p; p = strchr(vdi_spec, ':'); if (p) { *p++ = '#'; } uri = g_strdup_printf("sheepdog://%s/%s", host_spec, vdi_spec); /* * FIXME We to escape URI meta-characters, e.g. "x?y=z" * produces "sheepdog://x?y=z". Because of that ... */ sd_parse_uri(cfg, uri, &err); if (err) { /* * ... this can fail, but the error message is misleading. * Replace it by the traditional useless one until the * escaping is fixed. */ error_free(err); error_setg(errp, "Can't parse filename"); } g_free(q); g_free(uri); } static void sd_parse_filename(const char *filename, QDict *options, Error **errp) { Error *err = NULL; SheepdogConfig cfg; char buf[32]; if (strstr(filename, "://")) { sd_parse_uri(&cfg, filename, &err); } else { parse_vdiname(&cfg, filename, &err); } if (err) { error_propagate(errp, err); return; } if (cfg.path) { qdict_set_default_str(options, "server.path", cfg.path); qdict_set_default_str(options, "server.type", "unix"); } else { qdict_set_default_str(options, "server.type", "inet"); qdict_set_default_str(options, "server.host", cfg.host ?: SD_DEFAULT_ADDR); snprintf(buf, sizeof(buf), "%d", cfg.port ?: SD_DEFAULT_PORT); qdict_set_default_str(options, "server.port", buf); } qdict_set_default_str(options, "vdi", cfg.vdi); qdict_set_default_str(options, "tag", cfg.tag); if (cfg.snap_id) { snprintf(buf, sizeof(buf), "%d", cfg.snap_id); qdict_set_default_str(options, "snap-id", buf); } sd_config_done(&cfg); } static int find_vdi_name(BDRVSheepdogState *s, const char *filename, uint32_t snapid, const char *tag, uint32_t *vid, bool lock, Error **errp) { int ret, fd; SheepdogVdiReq hdr; SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; unsigned int wlen, rlen = 0; char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN] QEMU_NONSTRING; fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } /* This pair of strncpy calls ensures that the buffer is zero-filled, * which is desirable since we'll soon be sending those bytes, and * don't want the send_req to read uninitialized data. */ strncpy(buf, filename, SD_MAX_VDI_LEN); strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN); memset(&hdr, 0, sizeof(hdr)); if (lock) { hdr.opcode = SD_OP_LOCK_VDI; hdr.type = LOCK_TYPE_NORMAL; } else { hdr.opcode = SD_OP_GET_VDI_INFO; } wlen = SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN; hdr.proto_ver = SD_PROTO_VER; hdr.data_length = wlen; hdr.snapid = snapid; hdr.flags = SD_FLAG_CMD_WRITE; ret = do_req(fd, s->bs, (SheepdogReq *)&hdr, buf, &wlen, &rlen); if (ret) { error_setg_errno(errp, -ret, "cannot get vdi info"); goto out; } if (rsp->result != SD_RES_SUCCESS) { error_setg(errp, "cannot get vdi info, %s, %s %" PRIu32 " %s", sd_strerror(rsp->result), filename, snapid, tag); if (rsp->result == SD_RES_NO_VDI) { ret = -ENOENT; } else if (rsp->result == SD_RES_VDI_LOCKED) { ret = -EBUSY; } else { ret = -EIO; } goto out; } *vid = rsp->vdi_id; ret = 0; out: closesocket(fd); return ret; } static void coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, struct iovec *iov, int niov, enum AIOCBState aiocb_type) { int nr_copies = s->inode.nr_copies; SheepdogObjReq hdr; unsigned int wlen = 0; int ret; uint64_t oid = aio_req->oid; unsigned int datalen = aio_req->data_len; uint64_t offset = aio_req->offset; uint8_t flags = aio_req->flags; uint64_t old_oid = aio_req->base_oid; bool create = aio_req->create; qemu_co_mutex_lock(&s->queue_lock); QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings); qemu_co_mutex_unlock(&s->queue_lock); if (!nr_copies) { error_report("bug"); } memset(&hdr, 0, sizeof(hdr)); switch (aiocb_type) { case AIOCB_FLUSH_CACHE: hdr.opcode = SD_OP_FLUSH_VDI; break; case AIOCB_READ_UDATA: hdr.opcode = SD_OP_READ_OBJ; hdr.flags = flags; break; case AIOCB_WRITE_UDATA: if (create) { hdr.opcode = SD_OP_CREATE_AND_WRITE_OBJ; } else { hdr.opcode = SD_OP_WRITE_OBJ; } wlen = datalen; hdr.flags = SD_FLAG_CMD_WRITE | flags; break; case AIOCB_DISCARD_OBJ: hdr.opcode = SD_OP_WRITE_OBJ; hdr.flags = SD_FLAG_CMD_WRITE | flags; s->inode.data_vdi_id[data_oid_to_idx(oid)] = 0; offset = offsetof(SheepdogInode, data_vdi_id[data_oid_to_idx(oid)]); oid = vid_to_vdi_oid(s->inode.vdi_id); wlen = datalen = sizeof(uint32_t); break; } if (s->cache_flags) { hdr.flags |= s->cache_flags; } hdr.oid = oid; hdr.cow_oid = old_oid; hdr.copies = s->inode.nr_copies; hdr.data_length = datalen; hdr.offset = offset; hdr.id = aio_req->id; qemu_co_mutex_lock(&s->lock); s->co_send = qemu_coroutine_self(); aio_set_fd_handler(s->aio_context, s->fd, false, co_read_response, co_write_request, NULL, s); socket_set_cork(s->fd, 1); /* send a header */ ret = qemu_co_send(s->fd, &hdr, sizeof(hdr)); if (ret != sizeof(hdr)) { error_report("failed to send a req, %s", strerror(errno)); goto out; } if (wlen) { ret = qemu_co_sendv(s->fd, iov, niov, aio_req->iov_offset, wlen); if (ret != wlen) { error_report("failed to send a data, %s", strerror(errno)); } } out: socket_set_cork(s->fd, 0); aio_set_fd_handler(s->aio_context, s->fd, false, co_read_response, NULL, NULL, s); s->co_send = NULL; qemu_co_mutex_unlock(&s->lock); } static int read_write_object(int fd, BlockDriverState *bs, char *buf, uint64_t oid, uint8_t copies, unsigned int datalen, uint64_t offset, bool write, bool create, uint32_t cache_flags) { SheepdogObjReq hdr; SheepdogObjRsp *rsp = (SheepdogObjRsp *)&hdr; unsigned int wlen, rlen; int ret; memset(&hdr, 0, sizeof(hdr)); if (write) { wlen = datalen; rlen = 0; hdr.flags = SD_FLAG_CMD_WRITE; if (create) { hdr.opcode = SD_OP_CREATE_AND_WRITE_OBJ; } else { hdr.opcode = SD_OP_WRITE_OBJ; } } else { wlen = 0; rlen = datalen; hdr.opcode = SD_OP_READ_OBJ; } hdr.flags |= cache_flags; hdr.oid = oid; hdr.data_length = datalen; hdr.offset = offset; hdr.copies = copies; ret = do_req(fd, bs, (SheepdogReq *)&hdr, buf, &wlen, &rlen); if (ret) { error_report("failed to send a request to the sheep"); return ret; } switch (rsp->result) { case SD_RES_SUCCESS: return 0; default: error_report("%s", sd_strerror(rsp->result)); return -EIO; } } static int read_object(int fd, BlockDriverState *bs, char *buf, uint64_t oid, uint8_t copies, unsigned int datalen, uint64_t offset, uint32_t cache_flags) { return read_write_object(fd, bs, buf, oid, copies, datalen, offset, false, false, cache_flags); } static int write_object(int fd, BlockDriverState *bs, char *buf, uint64_t oid, uint8_t copies, unsigned int datalen, uint64_t offset, bool create, uint32_t cache_flags) { return read_write_object(fd, bs, buf, oid, copies, datalen, offset, true, create, cache_flags); } /* update inode with the latest state */ static int reload_inode(BDRVSheepdogState *s, uint32_t snapid, const char *tag) { Error *local_err = NULL; SheepdogInode *inode; int ret = 0, fd; uint32_t vid = 0; fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); return -EIO; } inode = g_malloc(SD_INODE_HEADER_SIZE); ret = find_vdi_name(s, s->name, snapid, tag, &vid, false, &local_err); if (ret) { error_report_err(local_err); goto out; } ret = read_object(fd, s->bs, (char *)inode, vid_to_vdi_oid(vid), s->inode.nr_copies, SD_INODE_HEADER_SIZE, 0, s->cache_flags); if (ret < 0) { goto out; } if (inode->vdi_id != s->inode.vdi_id) { memcpy(&s->inode, inode, SD_INODE_HEADER_SIZE); } out: g_free(inode); closesocket(fd); return ret; } static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req) { SheepdogAIOCB *acb = aio_req->aiocb; aio_req->create = false; /* check whether this request becomes a CoW one */ if (acb->aiocb_type == AIOCB_WRITE_UDATA && is_data_obj(aio_req->oid)) { int idx = data_oid_to_idx(aio_req->oid); if (is_data_obj_writable(&s->inode, idx)) { goto out; } if (s->inode.data_vdi_id[idx]) { aio_req->base_oid = vid_to_data_oid(s->inode.data_vdi_id[idx], idx); aio_req->flags |= SD_FLAG_CMD_COW; } aio_req->create = true; } out: if (is_data_obj(aio_req->oid)) { add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, acb->aiocb_type); } else { struct iovec iov; iov.iov_base = &s->inode; iov.iov_len = sizeof(s->inode); add_aio_request(s, aio_req, &iov, 1, AIOCB_WRITE_UDATA); } } static void sd_detach_aio_context(BlockDriverState *bs) { BDRVSheepdogState *s = bs->opaque; aio_set_fd_handler(s->aio_context, s->fd, false, NULL, NULL, NULL, NULL); } static void sd_attach_aio_context(BlockDriverState *bs, AioContext *new_context) { BDRVSheepdogState *s = bs->opaque; s->aio_context = new_context; aio_set_fd_handler(new_context, s->fd, false, co_read_response, NULL, NULL, s); } static QemuOptsList runtime_opts = { .name = "sheepdog", .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), .desc = { { .name = "vdi", .type = QEMU_OPT_STRING, }, { .name = "snap-id", .type = QEMU_OPT_NUMBER, }, { .name = "tag", .type = QEMU_OPT_STRING, }, { /* end of list */ } }, }; static int sd_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { int ret, fd; uint32_t vid = 0; BDRVSheepdogState *s = bs->opaque; const char *vdi, *snap_id_str, *tag; uint64_t snap_id; char *buf = NULL; QemuOpts *opts; Error *local_err = NULL; s->bs = bs; s->aio_context = bdrv_get_aio_context(bs); opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); qemu_opts_absorb_qdict(opts, options, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto err_no_fd; } s->addr = sd_server_config(options, errp); if (!s->addr) { ret = -EINVAL; goto err_no_fd; } vdi = qemu_opt_get(opts, "vdi"); snap_id_str = qemu_opt_get(opts, "snap-id"); snap_id = qemu_opt_get_number(opts, "snap-id", CURRENT_VDI_ID); tag = qemu_opt_get(opts, "tag"); if (!vdi) { error_setg(errp, "parameter 'vdi' is missing"); ret = -EINVAL; goto err_no_fd; } if (strlen(vdi) >= SD_MAX_VDI_LEN) { error_setg(errp, "value of parameter 'vdi' is too long"); ret = -EINVAL; goto err_no_fd; } if (snap_id > UINT32_MAX) { snap_id = 0; } if (snap_id_str && !snap_id) { error_setg(errp, "'snap-id=%s' is not a valid snapshot ID", snap_id_str); ret = -EINVAL; goto err_no_fd; } if (!tag) { tag = ""; } if (strlen(tag) >= SD_MAX_VDI_TAG_LEN) { error_setg(errp, "value of parameter 'tag' is too long"); ret = -EINVAL; goto err_no_fd; } QLIST_INIT(&s->inflight_aio_head); QLIST_INIT(&s->failed_aio_head); QLIST_INIT(&s->inflight_aiocb_head); s->fd = get_sheep_fd(s, errp); if (s->fd < 0) { ret = s->fd; goto err_no_fd; } ret = find_vdi_name(s, vdi, (uint32_t)snap_id, tag, &vid, true, errp); if (ret) { goto err; } /* * QEMU block layer emulates writethrough cache as 'writeback + flush', so * we always set SD_FLAG_CMD_CACHE (writeback cache) as default. */ s->cache_flags = SD_FLAG_CMD_CACHE; if (flags & BDRV_O_NOCACHE) { s->cache_flags = SD_FLAG_CMD_DIRECT; } s->discard_supported = true; if (snap_id || tag[0]) { trace_sheepdog_open(vid); s->is_snapshot = true; } fd = connect_to_sdog(s, errp); if (fd < 0) { ret = fd; goto err; } buf = g_malloc(SD_INODE_SIZE); ret = read_object(fd, s->bs, buf, vid_to_vdi_oid(vid), 0, SD_INODE_SIZE, 0, s->cache_flags); closesocket(fd); if (ret) { error_setg(errp, "Can't read snapshot inode"); goto err; } memcpy(&s->inode, buf, sizeof(s->inode)); bs->total_sectors = s->inode.vdi_size / BDRV_SECTOR_SIZE; bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; pstrcpy(s->name, sizeof(s->name), vdi); qemu_co_mutex_init(&s->lock); qemu_co_mutex_init(&s->queue_lock); qemu_co_queue_init(&s->overlapping_queue); qemu_opts_del(opts); g_free(buf); return 0; err: aio_set_fd_handler(bdrv_get_aio_context(bs), s->fd, false, NULL, NULL, NULL, NULL); closesocket(s->fd); err_no_fd: qemu_opts_del(opts); g_free(buf); return ret; } static int sd_reopen_prepare(BDRVReopenState *state, BlockReopenQueue *queue, Error **errp) { BDRVSheepdogState *s = state->bs->opaque; BDRVSheepdogReopenState *re_s; int ret = 0; re_s = state->opaque = g_new0(BDRVSheepdogReopenState, 1); re_s->cache_flags = SD_FLAG_CMD_CACHE; if (state->flags & BDRV_O_NOCACHE) { re_s->cache_flags = SD_FLAG_CMD_DIRECT; } re_s->fd = get_sheep_fd(s, errp); if (re_s->fd < 0) { ret = re_s->fd; return ret; } return ret; } static void sd_reopen_commit(BDRVReopenState *state) { BDRVSheepdogReopenState *re_s = state->opaque; BDRVSheepdogState *s = state->bs->opaque; if (s->fd) { aio_set_fd_handler(s->aio_context, s->fd, false, NULL, NULL, NULL, NULL); closesocket(s->fd); } s->fd = re_s->fd; s->cache_flags = re_s->cache_flags; g_free(state->opaque); state->opaque = NULL; return; } static void sd_reopen_abort(BDRVReopenState *state) { BDRVSheepdogReopenState *re_s = state->opaque; BDRVSheepdogState *s = state->bs->opaque; if (re_s == NULL) { return; } if (re_s->fd) { aio_set_fd_handler(s->aio_context, re_s->fd, false, NULL, NULL, NULL, NULL); closesocket(re_s->fd); } g_free(state->opaque); state->opaque = NULL; return; } static int do_sd_create(BDRVSheepdogState *s, uint32_t *vdi_id, int snapshot, Error **errp) { SheepdogVdiReq hdr; SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; int fd, ret; unsigned int wlen, rlen = 0; char buf[SD_MAX_VDI_LEN]; fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } /* FIXME: would it be better to fail (e.g., return -EIO) when filename * does not fit in buf? For now, just truncate and avoid buffer overrun. */ memset(buf, 0, sizeof(buf)); pstrcpy(buf, sizeof(buf), s->name); memset(&hdr, 0, sizeof(hdr)); hdr.opcode = SD_OP_NEW_VDI; hdr.base_vdi_id = s->inode.vdi_id; wlen = SD_MAX_VDI_LEN; hdr.flags = SD_FLAG_CMD_WRITE; hdr.snapid = snapshot; hdr.data_length = wlen; hdr.vdi_size = s->inode.vdi_size; hdr.copy_policy = s->inode.copy_policy; hdr.copies = s->inode.nr_copies; hdr.block_size_shift = s->inode.block_size_shift; ret = do_req(fd, NULL, (SheepdogReq *)&hdr, buf, &wlen, &rlen); closesocket(fd); if (ret) { error_setg_errno(errp, -ret, "create failed"); return ret; } if (rsp->result != SD_RES_SUCCESS) { error_setg(errp, "%s, %s", sd_strerror(rsp->result), s->inode.name); return -EIO; } if (vdi_id) { *vdi_id = rsp->vdi_id; } return 0; } static int sd_prealloc(BlockDriverState *bs, int64_t old_size, int64_t new_size, Error **errp) { BlockBackend *blk = NULL; BDRVSheepdogState *base = bs->opaque; unsigned long buf_size; uint32_t idx, max_idx; uint32_t object_size; void *buf = NULL; int ret; blk = blk_new_with_bs(bs, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, errp); if (!blk) { ret = -EPERM; goto out_with_err_set; } blk_set_allow_write_beyond_eof(blk, true); object_size = (UINT32_C(1) << base->inode.block_size_shift); buf_size = MIN(object_size, SD_DATA_OBJ_SIZE); buf = g_malloc0(buf_size); max_idx = DIV_ROUND_UP(new_size, buf_size); for (idx = old_size / buf_size; idx < max_idx; idx++) { /* * The created image can be a cloned image, so we need to read * a data from the source image. */ ret = blk_pread(blk, idx * buf_size, buf, buf_size); if (ret < 0) { goto out; } ret = blk_pwrite(blk, idx * buf_size, buf, buf_size, 0); if (ret < 0) { goto out; } } ret = 0; out: if (ret < 0) { error_setg_errno(errp, -ret, "Can't pre-allocate"); } out_with_err_set: blk_unref(blk); g_free(buf); return ret; } static int sd_create_prealloc(BlockdevOptionsSheepdog *location, int64_t size, Error **errp) { BlockDriverState *bs; Visitor *v; QObject *obj = NULL; QDict *qdict; int ret; v = qobject_output_visitor_new(&obj); visit_type_BlockdevOptionsSheepdog(v, NULL, &location, &error_abort); visit_free(v); qdict = qobject_to(QDict, obj); qdict_flatten(qdict); qdict_put_str(qdict, "driver", "sheepdog"); bs = bdrv_open(NULL, NULL, qdict, BDRV_O_PROTOCOL | BDRV_O_RDWR, errp); if (bs == NULL) { ret = -EIO; goto fail; } ret = sd_prealloc(bs, 0, size, errp); fail: bdrv_unref(bs); qobject_unref(qdict); return ret; } static int parse_redundancy(BDRVSheepdogState *s, SheepdogRedundancy *opt) { struct SheepdogInode *inode = &s->inode; switch (opt->type) { case SHEEPDOG_REDUNDANCY_TYPE_FULL: if (opt->u.full.copies > SD_MAX_COPIES || opt->u.full.copies < 1) { return -EINVAL; } inode->copy_policy = 0; inode->nr_copies = opt->u.full.copies; return 0; case SHEEPDOG_REDUNDANCY_TYPE_ERASURE_CODED: { int64_t copy = opt->u.erasure_coded.data_strips; int64_t parity = opt->u.erasure_coded.parity_strips; if (copy != 2 && copy != 4 && copy != 8 && copy != 16) { return -EINVAL; } if (parity >= SD_EC_MAX_STRIP || parity < 1) { return -EINVAL; } /* * 4 bits for parity and 4 bits for data. * We have to compress upper data bits because it can't represent 16 */ inode->copy_policy = ((copy / 2) << 4) + parity; inode->nr_copies = copy + parity; return 0; } default: g_assert_not_reached(); } return -EINVAL; } /* * Sheepdog support two kinds of redundancy, full replication and erasure * coding. * * # create a fully replicated vdi with x copies * -o redundancy=x (1 <= x <= SD_MAX_COPIES) * * # create a erasure coded vdi with x data strips and y parity strips * -o redundancy=x:y (x must be one of {2,4,8,16} and 1 <= y < SD_EC_MAX_STRIP) */ static SheepdogRedundancy *parse_redundancy_str(const char *opt) { SheepdogRedundancy *redundancy; const char *n1, *n2; long copy, parity; char p[10]; int ret; pstrcpy(p, sizeof(p), opt); n1 = strtok(p, ":"); n2 = strtok(NULL, ":"); if (!n1) { return NULL; } ret = qemu_strtol(n1, NULL, 10, ©); if (ret < 0) { return NULL; } redundancy = g_new0(SheepdogRedundancy, 1); if (!n2) { *redundancy = (SheepdogRedundancy) { .type = SHEEPDOG_REDUNDANCY_TYPE_FULL, .u.full.copies = copy, }; } else { ret = qemu_strtol(n2, NULL, 10, &parity); if (ret < 0) { g_free(redundancy); return NULL; } *redundancy = (SheepdogRedundancy) { .type = SHEEPDOG_REDUNDANCY_TYPE_ERASURE_CODED, .u.erasure_coded = { .data_strips = copy, .parity_strips = parity, }, }; } return redundancy; } static int parse_block_size_shift(BDRVSheepdogState *s, BlockdevCreateOptionsSheepdog *opts) { struct SheepdogInode *inode = &s->inode; uint64_t object_size; int obj_order; if (opts->has_object_size) { object_size = opts->object_size; if ((object_size - 1) & object_size) { /* not a power of 2? */ return -EINVAL; } obj_order = ctz32(object_size); if (obj_order < 20 || obj_order > 31) { return -EINVAL; } inode->block_size_shift = (uint8_t)obj_order; } return 0; } static int sd_co_create(BlockdevCreateOptions *options, Error **errp) { BlockdevCreateOptionsSheepdog *opts = &options->u.sheepdog; int ret = 0; uint32_t vid = 0; char *backing_file = NULL; char *buf = NULL; BDRVSheepdogState *s; uint64_t max_vdi_size; bool prealloc = false; assert(options->driver == BLOCKDEV_DRIVER_SHEEPDOG); s = g_new0(BDRVSheepdogState, 1); /* Steal SocketAddress from QAPI, set NULL to prevent double free */ s->addr = opts->location->server; opts->location->server = NULL; if (strlen(opts->location->vdi) >= sizeof(s->name)) { error_setg(errp, "'vdi' string too long"); ret = -EINVAL; goto out; } pstrcpy(s->name, sizeof(s->name), opts->location->vdi); s->inode.vdi_size = opts->size; backing_file = opts->backing_file; if (!opts->has_preallocation) { opts->preallocation = PREALLOC_MODE_OFF; } switch (opts->preallocation) { case PREALLOC_MODE_OFF: prealloc = false; break; case PREALLOC_MODE_FULL: prealloc = true; break; default: error_setg(errp, "Preallocation mode not supported for Sheepdog"); ret = -EINVAL; goto out; } if (opts->has_redundancy) { ret = parse_redundancy(s, opts->redundancy); if (ret < 0) { error_setg(errp, "Invalid redundancy mode"); goto out; } } ret = parse_block_size_shift(s, opts); if (ret < 0) { error_setg(errp, "Invalid object_size." " obect_size needs to be power of 2" " and be limited from 2^20 to 2^31"); goto out; } if (opts->has_backing_file) { BlockBackend *blk; BDRVSheepdogState *base; BlockDriver *drv; /* Currently, only Sheepdog backing image is supported. */ drv = bdrv_find_protocol(opts->backing_file, true, NULL); if (!drv || strcmp(drv->protocol_name, "sheepdog") != 0) { error_setg(errp, "backing_file must be a sheepdog image"); ret = -EINVAL; goto out; } blk = blk_new_open(opts->backing_file, NULL, NULL, BDRV_O_PROTOCOL, errp); if (blk == NULL) { ret = -EIO; goto out; } base = blk_bs(blk)->opaque; if (!is_snapshot(&base->inode)) { error_setg(errp, "cannot clone from a non snapshot vdi"); blk_unref(blk); ret = -EINVAL; goto out; } s->inode.vdi_id = base->inode.vdi_id; blk_unref(blk); } s->aio_context = qemu_get_aio_context(); /* if block_size_shift is not specified, get cluster default value */ if (s->inode.block_size_shift == 0) { SheepdogVdiReq hdr; SheepdogClusterRsp *rsp = (SheepdogClusterRsp *)&hdr; int fd; unsigned int wlen = 0, rlen = 0; fd = connect_to_sdog(s, errp); if (fd < 0) { ret = fd; goto out; } memset(&hdr, 0, sizeof(hdr)); hdr.opcode = SD_OP_GET_CLUSTER_DEFAULT; hdr.proto_ver = SD_PROTO_VER; ret = do_req(fd, NULL, (SheepdogReq *)&hdr, NULL, &wlen, &rlen); closesocket(fd); if (ret) { error_setg_errno(errp, -ret, "failed to get cluster default"); goto out; } if (rsp->result == SD_RES_SUCCESS) { s->inode.block_size_shift = rsp->block_size_shift; } else { s->inode.block_size_shift = SD_DEFAULT_BLOCK_SIZE_SHIFT; } } max_vdi_size = (UINT64_C(1) << s->inode.block_size_shift) * MAX_DATA_OBJS; if (s->inode.vdi_size > max_vdi_size) { error_setg(errp, "An image is too large." " The maximum image size is %"PRIu64 "GB", max_vdi_size / 1024 / 1024 / 1024); ret = -EINVAL; goto out; } ret = do_sd_create(s, &vid, 0, errp); if (ret) { goto out; } if (prealloc) { ret = sd_create_prealloc(opts->location, opts->size, errp); } out: g_free(backing_file); g_free(buf); g_free(s->addr); g_free(s); return ret; } static int coroutine_fn sd_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, Error **errp) { BlockdevCreateOptions *create_options = NULL; QDict *qdict, *location_qdict; Visitor *v; char *redundancy; Error *local_err = NULL; int ret; redundancy = qemu_opt_get_del(opts, BLOCK_OPT_REDUNDANCY); qdict = qemu_opts_to_qdict(opts, NULL); qdict_put_str(qdict, "driver", "sheepdog"); location_qdict = qdict_new(); qdict_put(qdict, "location", location_qdict); sd_parse_filename(filename, location_qdict, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } qdict_flatten(qdict); /* Change legacy command line options into QMP ones */ static const QDictRenames opt_renames[] = { { BLOCK_OPT_BACKING_FILE, "backing-file" }, { BLOCK_OPT_OBJECT_SIZE, "object-size" }, { NULL, NULL }, }; if (!qdict_rename_keys(qdict, opt_renames, errp)) { ret = -EINVAL; goto fail; } /* Get the QAPI object */ v = qobject_input_visitor_new_flat_confused(qdict, errp); if (!v) { ret = -EINVAL; goto fail; } visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); visit_free(v); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } assert(create_options->driver == BLOCKDEV_DRIVER_SHEEPDOG); create_options->u.sheepdog.size = ROUND_UP(create_options->u.sheepdog.size, BDRV_SECTOR_SIZE); if (redundancy) { create_options->u.sheepdog.has_redundancy = true; create_options->u.sheepdog.redundancy = parse_redundancy_str(redundancy); if (create_options->u.sheepdog.redundancy == NULL) { error_setg(errp, "Invalid redundancy mode"); ret = -EINVAL; goto fail; } } ret = sd_co_create(create_options, errp); fail: qapi_free_BlockdevCreateOptions(create_options); qobject_unref(qdict); g_free(redundancy); return ret; } static void sd_close(BlockDriverState *bs) { Error *local_err = NULL; BDRVSheepdogState *s = bs->opaque; SheepdogVdiReq hdr; SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; unsigned int wlen, rlen = 0; int fd, ret; trace_sheepdog_close(s->name); fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); return; } memset(&hdr, 0, sizeof(hdr)); hdr.opcode = SD_OP_RELEASE_VDI; hdr.type = LOCK_TYPE_NORMAL; hdr.base_vdi_id = s->inode.vdi_id; wlen = strlen(s->name) + 1; hdr.data_length = wlen; hdr.flags = SD_FLAG_CMD_WRITE; ret = do_req(fd, s->bs, (SheepdogReq *)&hdr, s->name, &wlen, &rlen); closesocket(fd); if (!ret && rsp->result != SD_RES_SUCCESS && rsp->result != SD_RES_VDI_NOT_LOCKED) { error_report("%s, %s", sd_strerror(rsp->result), s->name); } aio_set_fd_handler(bdrv_get_aio_context(bs), s->fd, false, NULL, NULL, NULL, NULL); closesocket(s->fd); qapi_free_SocketAddress(s->addr); } static int64_t sd_getlength(BlockDriverState *bs) { BDRVSheepdogState *s = bs->opaque; return s->inode.vdi_size; } static int coroutine_fn sd_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) { BDRVSheepdogState *s = bs->opaque; int ret, fd; unsigned int datalen; uint64_t max_vdi_size; int64_t old_size = s->inode.vdi_size; if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_FULL) { error_setg(errp, "Unsupported preallocation mode '%s'", PreallocMode_str(prealloc)); return -ENOTSUP; } max_vdi_size = (UINT64_C(1) << s->inode.block_size_shift) * MAX_DATA_OBJS; if (offset < old_size) { error_setg(errp, "shrinking is not supported"); return -EINVAL; } else if (offset > max_vdi_size) { error_setg(errp, "too big image size"); return -EINVAL; } fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } /* we don't need to update entire object */ datalen = SD_INODE_HEADER_SIZE; s->inode.vdi_size = offset; ret = write_object(fd, s->bs, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id), s->inode.nr_copies, datalen, 0, false, s->cache_flags); close(fd); if (ret < 0) { error_setg_errno(errp, -ret, "failed to update an inode"); return ret; } if (prealloc == PREALLOC_MODE_FULL) { ret = sd_prealloc(bs, old_size, offset, errp); if (ret < 0) { return ret; } } return 0; } /* * This function is called after writing data objects. If we need to * update metadata, this sends a write request to the vdi object. */ static void coroutine_fn sd_write_done(SheepdogAIOCB *acb) { BDRVSheepdogState *s = acb->s; struct iovec iov; AIOReq *aio_req; uint32_t offset, data_len, mn, mx; mn = acb->min_dirty_data_idx; mx = acb->max_dirty_data_idx; if (mn <= mx) { /* we need to update the vdi object. */ ++acb->nr_pending; offset = sizeof(s->inode) - sizeof(s->inode.data_vdi_id) + mn * sizeof(s->inode.data_vdi_id[0]); data_len = (mx - mn + 1) * sizeof(s->inode.data_vdi_id[0]); acb->min_dirty_data_idx = UINT32_MAX; acb->max_dirty_data_idx = 0; iov.iov_base = &s->inode; iov.iov_len = sizeof(s->inode); aio_req = alloc_aio_req(s, acb, vid_to_vdi_oid(s->inode.vdi_id), data_len, offset, 0, false, 0, offset); add_aio_request(s, aio_req, &iov, 1, AIOCB_WRITE_UDATA); if (--acb->nr_pending) { qemu_coroutine_yield(); } } } /* Delete current working VDI on the snapshot chain */ static bool sd_delete(BDRVSheepdogState *s) { Error *local_err = NULL; unsigned int wlen = SD_MAX_VDI_LEN, rlen = 0; SheepdogVdiReq hdr = { .opcode = SD_OP_DEL_VDI, .base_vdi_id = s->inode.vdi_id, .data_length = wlen, .flags = SD_FLAG_CMD_WRITE, }; SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; int fd, ret; fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); return false; } ret = do_req(fd, s->bs, (SheepdogReq *)&hdr, s->name, &wlen, &rlen); closesocket(fd); if (ret) { return false; } switch (rsp->result) { case SD_RES_NO_VDI: error_report("%s was already deleted", s->name); /* fall through */ case SD_RES_SUCCESS: break; default: error_report("%s, %s", sd_strerror(rsp->result), s->name); return false; } return true; } /* * Create a writable VDI from a snapshot */ static int sd_create_branch(BDRVSheepdogState *s) { Error *local_err = NULL; int ret, fd; uint32_t vid; char *buf; bool deleted; trace_sheepdog_create_branch_snapshot(s->inode.vdi_id); buf = g_malloc(SD_INODE_SIZE); /* * Even If deletion fails, we will just create extra snapshot based on * the working VDI which was supposed to be deleted. So no need to * false bail out. */ deleted = sd_delete(s); ret = do_sd_create(s, &vid, !deleted, &local_err); if (ret) { error_report_err(local_err); goto out; } trace_sheepdog_create_branch_created(vid); fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); ret = fd; goto out; } ret = read_object(fd, s->bs, buf, vid_to_vdi_oid(vid), s->inode.nr_copies, SD_INODE_SIZE, 0, s->cache_flags); closesocket(fd); if (ret < 0) { goto out; } memcpy(&s->inode, buf, sizeof(s->inode)); s->is_snapshot = false; ret = 0; trace_sheepdog_create_branch_new(s->inode.vdi_id); out: g_free(buf); return ret; } /* * Send I/O requests to the server. * * This function sends requests to the server, links the requests to * the inflight_list in BDRVSheepdogState, and exits without * waiting the response. The responses are received in the * `aio_read_response' function which is called from the main loop as * a fd handler. * * Returns 1 when we need to wait a response, 0 when there is no sent * request and -errno in error cases. */ static void coroutine_fn sd_co_rw_vector(SheepdogAIOCB *acb) { int ret = 0; unsigned long len, done = 0, total = acb->nb_sectors * BDRV_SECTOR_SIZE; unsigned long idx; uint32_t object_size; uint64_t oid; uint64_t offset; BDRVSheepdogState *s = acb->s; SheepdogInode *inode = &s->inode; AIOReq *aio_req; if (acb->aiocb_type == AIOCB_WRITE_UDATA && s->is_snapshot) { /* * In the case we open the snapshot VDI, Sheepdog creates the * writable VDI when we do a write operation first. */ ret = sd_create_branch(s); if (ret) { acb->ret = -EIO; return; } } object_size = (UINT32_C(1) << inode->block_size_shift); idx = acb->sector_num * BDRV_SECTOR_SIZE / object_size; offset = (acb->sector_num * BDRV_SECTOR_SIZE) % object_size; /* * Make sure we don't free the aiocb before we are done with all requests. * This additional reference is dropped at the end of this function. */ acb->nr_pending++; while (done != total) { uint8_t flags = 0; uint64_t old_oid = 0; bool create = false; oid = vid_to_data_oid(inode->data_vdi_id[idx], idx); len = MIN(total - done, object_size - offset); switch (acb->aiocb_type) { case AIOCB_READ_UDATA: if (!inode->data_vdi_id[idx]) { qemu_iovec_memset(acb->qiov, done, 0, len); goto done; } break; case AIOCB_WRITE_UDATA: if (!inode->data_vdi_id[idx]) { create = true; } else if (!is_data_obj_writable(inode, idx)) { /* Copy-On-Write */ create = true; old_oid = oid; flags = SD_FLAG_CMD_COW; } break; case AIOCB_DISCARD_OBJ: /* * We discard the object only when the whole object is * 1) allocated 2) trimmed. Otherwise, simply skip it. */ if (len != object_size || inode->data_vdi_id[idx] == 0) { goto done; } break; default: break; } if (create) { trace_sheepdog_co_rw_vector_update(inode->vdi_id, oid, vid_to_data_oid(inode->data_vdi_id[idx], idx), idx); oid = vid_to_data_oid(inode->vdi_id, idx); trace_sheepdog_co_rw_vector_new(oid); } aio_req = alloc_aio_req(s, acb, oid, len, offset, flags, create, old_oid, acb->aiocb_type == AIOCB_DISCARD_OBJ ? 0 : done); add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, acb->aiocb_type); done: offset = 0; idx++; done += len; } if (--acb->nr_pending) { qemu_coroutine_yield(); } } static void sd_aio_complete(SheepdogAIOCB *acb) { BDRVSheepdogState *s; if (acb->aiocb_type == AIOCB_FLUSH_CACHE) { return; } s = acb->s; qemu_co_mutex_lock(&s->queue_lock); QLIST_REMOVE(acb, aiocb_siblings); qemu_co_queue_restart_all(&s->overlapping_queue); qemu_co_mutex_unlock(&s->queue_lock); } static coroutine_fn int sd_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags) { SheepdogAIOCB acb; int ret; int64_t offset = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE; BDRVSheepdogState *s = bs->opaque; assert(!flags); if (offset > s->inode.vdi_size) { ret = sd_co_truncate(bs, offset, false, PREALLOC_MODE_OFF, 0, NULL); if (ret < 0) { return ret; } } sd_aio_setup(&acb, s, qiov, sector_num, nb_sectors, AIOCB_WRITE_UDATA); sd_co_rw_vector(&acb); sd_write_done(&acb); sd_aio_complete(&acb); return acb.ret; } static coroutine_fn int sd_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { SheepdogAIOCB acb; BDRVSheepdogState *s = bs->opaque; sd_aio_setup(&acb, s, qiov, sector_num, nb_sectors, AIOCB_READ_UDATA); sd_co_rw_vector(&acb); sd_aio_complete(&acb); return acb.ret; } static int coroutine_fn sd_co_flush_to_disk(BlockDriverState *bs) { BDRVSheepdogState *s = bs->opaque; SheepdogAIOCB acb; AIOReq *aio_req; if (s->cache_flags != SD_FLAG_CMD_CACHE) { return 0; } sd_aio_setup(&acb, s, NULL, 0, 0, AIOCB_FLUSH_CACHE); acb.nr_pending++; aio_req = alloc_aio_req(s, &acb, vid_to_vdi_oid(s->inode.vdi_id), 0, 0, 0, false, 0, 0); add_aio_request(s, aio_req, NULL, 0, acb.aiocb_type); if (--acb.nr_pending) { qemu_coroutine_yield(); } sd_aio_complete(&acb); return acb.ret; } static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) { Error *local_err = NULL; BDRVSheepdogState *s = bs->opaque; int ret, fd; uint32_t new_vid; SheepdogInode *inode; unsigned int datalen; trace_sheepdog_snapshot_create_info(sn_info->name, sn_info->id_str, s->name, sn_info->vm_state_size, s->is_snapshot); if (s->is_snapshot) { error_report("You can't create a snapshot of a snapshot VDI, " "%s (%" PRIu32 ").", s->name, s->inode.vdi_id); return -EINVAL; } trace_sheepdog_snapshot_create(sn_info->name, sn_info->id_str); s->inode.vm_state_size = sn_info->vm_state_size; s->inode.vm_clock_nsec = sn_info->vm_clock_nsec; /* It appears that inode.tag does not require a NUL terminator, * which means this use of strncpy is ok. */ strncpy(s->inode.tag, sn_info->name, sizeof(s->inode.tag)); /* we don't need to update entire object */ datalen = SD_INODE_HEADER_SIZE; inode = g_malloc(datalen); /* refresh inode. */ fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); ret = fd; goto cleanup; } ret = write_object(fd, s->bs, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id), s->inode.nr_copies, datalen, 0, false, s->cache_flags); if (ret < 0) { error_report("failed to write snapshot's inode."); goto cleanup; } ret = do_sd_create(s, &new_vid, 1, &local_err); if (ret < 0) { error_reportf_err(local_err, "failed to create inode for snapshot: "); goto cleanup; } ret = read_object(fd, s->bs, (char *)inode, vid_to_vdi_oid(new_vid), s->inode.nr_copies, datalen, 0, s->cache_flags); if (ret < 0) { error_report("failed to read new inode info. %s", strerror(errno)); goto cleanup; } memcpy(&s->inode, inode, datalen); trace_sheepdog_snapshot_create_inode(s->inode.name, s->inode.snap_id, s->inode.vdi_id); cleanup: g_free(inode); closesocket(fd); return ret; } /* * We implement rollback(loadvm) operation to the specified snapshot by * 1) switch to the snapshot * 2) rely on sd_create_branch to delete working VDI and * 3) create a new working VDI based on the specified snapshot */ static int sd_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) { BDRVSheepdogState *s = bs->opaque; BDRVSheepdogState *old_s; char tag[SD_MAX_VDI_TAG_LEN]; uint32_t snapid = 0; int ret; if (!sd_parse_snapid_or_tag(snapshot_id, &snapid, tag)) { return -EINVAL; } old_s = g_new(BDRVSheepdogState, 1); memcpy(old_s, s, sizeof(BDRVSheepdogState)); ret = reload_inode(s, snapid, tag); if (ret) { goto out; } ret = sd_create_branch(s); if (ret) { goto out; } g_free(old_s); return 0; out: /* recover bdrv_sd_state */ memcpy(s, old_s, sizeof(BDRVSheepdogState)); g_free(old_s); error_report("failed to open. recover old bdrv_sd_state."); return ret; } #define NR_BATCHED_DISCARD 128 static int remove_objects(BDRVSheepdogState *s, Error **errp) { int fd, i = 0, nr_objs = 0; int ret; SheepdogInode *inode = &s->inode; fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } nr_objs = count_data_objs(inode); while (i < nr_objs) { int start_idx, nr_filled_idx; while (i < nr_objs && !inode->data_vdi_id[i]) { i++; } start_idx = i; nr_filled_idx = 0; while (i < nr_objs && nr_filled_idx < NR_BATCHED_DISCARD) { if (inode->data_vdi_id[i]) { inode->data_vdi_id[i] = 0; nr_filled_idx++; } i++; } ret = write_object(fd, s->bs, (char *)&inode->data_vdi_id[start_idx], vid_to_vdi_oid(s->inode.vdi_id), inode->nr_copies, (i - start_idx) * sizeof(uint32_t), offsetof(struct SheepdogInode, data_vdi_id[start_idx]), false, s->cache_flags); if (ret < 0) { error_setg(errp, "Failed to discard snapshot inode"); goto out; } } ret = 0; out: closesocket(fd); return ret; } static int sd_snapshot_delete(BlockDriverState *bs, const char *snapshot_id, const char *name, Error **errp) { /* * FIXME should delete the snapshot matching both @snapshot_id and * @name, but @name not used here */ unsigned long snap_id = 0; char snap_tag[SD_MAX_VDI_TAG_LEN]; int fd, ret; char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN]; BDRVSheepdogState *s = bs->opaque; unsigned int wlen = SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN, rlen = 0; uint32_t vid; SheepdogVdiReq hdr = { .opcode = SD_OP_DEL_VDI, .data_length = wlen, .flags = SD_FLAG_CMD_WRITE, }; SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; ret = remove_objects(s, errp); if (ret) { return ret; } memset(buf, 0, sizeof(buf)); memset(snap_tag, 0, sizeof(snap_tag)); pstrcpy(buf, SD_MAX_VDI_LEN, s->name); /* TODO Use sd_parse_snapid() once this mess is cleaned up */ ret = qemu_strtoul(snapshot_id, NULL, 10, &snap_id); if (ret || snap_id > UINT32_MAX) { /* * FIXME Since qemu_strtoul() returns -EINVAL when * @snapshot_id is null, @snapshot_id is mandatory. Correct * would be to require at least one of @snapshot_id and @name. */ error_setg(errp, "Invalid snapshot ID: %s", snapshot_id ? snapshot_id : ""); return -EINVAL; } if (snap_id) { hdr.snapid = (uint32_t) snap_id; } else { /* FIXME I suspect we should use @name here */ /* FIXME don't truncate silently */ pstrcpy(snap_tag, sizeof(snap_tag), snapshot_id); pstrcpy(buf + SD_MAX_VDI_LEN, SD_MAX_VDI_TAG_LEN, snap_tag); } ret = find_vdi_name(s, s->name, snap_id, snap_tag, &vid, true, errp); if (ret) { return ret; } fd = connect_to_sdog(s, errp); if (fd < 0) { return fd; } ret = do_req(fd, s->bs, (SheepdogReq *)&hdr, buf, &wlen, &rlen); closesocket(fd); if (ret) { error_setg_errno(errp, -ret, "Couldn't send request to server"); return ret; } switch (rsp->result) { case SD_RES_NO_VDI: error_setg(errp, "Can't find the snapshot"); return -ENOENT; case SD_RES_SUCCESS: break; default: error_setg(errp, "%s", sd_strerror(rsp->result)); return -EIO; } return 0; } static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) { Error *local_err = NULL; BDRVSheepdogState *s = bs->opaque; SheepdogReq req; int fd, nr = 1024, ret, max = BITS_TO_LONGS(SD_NR_VDIS) * sizeof(long); QEMUSnapshotInfo *sn_tab = NULL; unsigned wlen, rlen; int found = 0; SheepdogInode *inode; unsigned long *vdi_inuse; unsigned int start_nr; uint64_t hval; uint32_t vid; vdi_inuse = g_malloc(max); inode = g_malloc(SD_INODE_HEADER_SIZE); fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); ret = fd; goto out; } rlen = max; wlen = 0; memset(&req, 0, sizeof(req)); req.opcode = SD_OP_READ_VDIS; req.data_length = max; ret = do_req(fd, s->bs, &req, vdi_inuse, &wlen, &rlen); closesocket(fd); if (ret) { goto out; } sn_tab = g_new0(QEMUSnapshotInfo, nr); /* calculate a vdi id with hash function */ hval = fnv_64a_buf(s->name, strlen(s->name), FNV1A_64_INIT); start_nr = hval & (SD_NR_VDIS - 1); fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); ret = fd; goto out; } for (vid = start_nr; found < nr; vid = (vid + 1) % SD_NR_VDIS) { if (!test_bit(vid, vdi_inuse)) { break; } /* we don't need to read entire object */ ret = read_object(fd, s->bs, (char *)inode, vid_to_vdi_oid(vid), 0, SD_INODE_HEADER_SIZE, 0, s->cache_flags); if (ret) { continue; } if (!strcmp(inode->name, s->name) && is_snapshot(inode)) { sn_tab[found].date_sec = inode->snap_ctime >> 32; sn_tab[found].date_nsec = inode->snap_ctime & 0xffffffff; sn_tab[found].vm_state_size = inode->vm_state_size; sn_tab[found].vm_clock_nsec = inode->vm_clock_nsec; snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str), "%" PRIu32, inode->snap_id); pstrcpy(sn_tab[found].name, MIN(sizeof(sn_tab[found].name), sizeof(inode->tag)), inode->tag); found++; } } closesocket(fd); out: *psn_tab = sn_tab; g_free(vdi_inuse); g_free(inode); if (ret < 0) { return ret; } return found; } static int do_load_save_vmstate(BDRVSheepdogState *s, uint8_t *data, int64_t pos, int size, int load) { Error *local_err = NULL; bool create; int fd, ret = 0, remaining = size; unsigned int data_len; uint64_t vmstate_oid; uint64_t offset; uint32_t vdi_index; uint32_t vdi_id = load ? s->inode.parent_vdi_id : s->inode.vdi_id; uint32_t object_size = (UINT32_C(1) << s->inode.block_size_shift); fd = connect_to_sdog(s, &local_err); if (fd < 0) { error_report_err(local_err); return fd; } while (remaining) { vdi_index = pos / object_size; offset = pos % object_size; data_len = MIN(remaining, object_size - offset); vmstate_oid = vid_to_vmstate_oid(vdi_id, vdi_index); create = (offset == 0); if (load) { ret = read_object(fd, s->bs, (char *)data, vmstate_oid, s->inode.nr_copies, data_len, offset, s->cache_flags); } else { ret = write_object(fd, s->bs, (char *)data, vmstate_oid, s->inode.nr_copies, data_len, offset, create, s->cache_flags); } if (ret < 0) { error_report("failed to save vmstate %s", strerror(errno)); goto cleanup; } pos += data_len; data += data_len; remaining -= data_len; } ret = size; cleanup: closesocket(fd); return ret; } static int sd_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) { BDRVSheepdogState *s = bs->opaque; void *buf; int ret; buf = qemu_blockalign(bs, qiov->size); qemu_iovec_to_buf(qiov, 0, buf, qiov->size); ret = do_load_save_vmstate(s, (uint8_t *) buf, pos, qiov->size, 0); qemu_vfree(buf); return ret; } static int sd_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) { BDRVSheepdogState *s = bs->opaque; void *buf; int ret; buf = qemu_blockalign(bs, qiov->size); ret = do_load_save_vmstate(s, buf, pos, qiov->size, 1); qemu_iovec_from_buf(qiov, 0, buf, qiov->size); qemu_vfree(buf); return ret; } static coroutine_fn int sd_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) { SheepdogAIOCB acb; BDRVSheepdogState *s = bs->opaque; QEMUIOVector discard_iov; struct iovec iov; uint32_t zero = 0; if (!s->discard_supported) { return 0; } memset(&discard_iov, 0, sizeof(discard_iov)); memset(&iov, 0, sizeof(iov)); iov.iov_base = &zero; iov.iov_len = sizeof(zero); discard_iov.iov = &iov; discard_iov.niov = 1; if (!QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE)) { return -ENOTSUP; } sd_aio_setup(&acb, s, &discard_iov, offset >> BDRV_SECTOR_BITS, bytes >> BDRV_SECTOR_BITS, AIOCB_DISCARD_OBJ); sd_co_rw_vector(&acb); sd_aio_complete(&acb); return acb.ret; } static coroutine_fn int sd_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file) { BDRVSheepdogState *s = bs->opaque; SheepdogInode *inode = &s->inode; uint32_t object_size = (UINT32_C(1) << inode->block_size_shift); unsigned long start = offset / object_size, end = DIV_ROUND_UP(offset + bytes, object_size); unsigned long idx; *map = offset; int ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; for (idx = start; idx < end; idx++) { if (inode->data_vdi_id[idx] == 0) { break; } } if (idx == start) { /* Get the longest length of unallocated sectors */ ret = 0; for (idx = start + 1; idx < end; idx++) { if (inode->data_vdi_id[idx] != 0) { break; } } } *pnum = (idx - start) * object_size; if (*pnum > bytes) { *pnum = bytes; } if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) { *file = bs; } return ret; } static int64_t sd_get_allocated_file_size(BlockDriverState *bs) { BDRVSheepdogState *s = bs->opaque; SheepdogInode *inode = &s->inode; uint32_t object_size = (UINT32_C(1) << inode->block_size_shift); unsigned long i, last = DIV_ROUND_UP(inode->vdi_size, object_size); uint64_t size = 0; for (i = 0; i < last; i++) { if (inode->data_vdi_id[i] == 0) { continue; } size += object_size; } return size; } static QemuOptsList sd_create_opts = { .name = "sheepdog-create-opts", .head = QTAILQ_HEAD_INITIALIZER(sd_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, { .name = BLOCK_OPT_BACKING_FILE, .type = QEMU_OPT_STRING, .help = "File name of a base image" }, { .name = BLOCK_OPT_PREALLOC, .type = QEMU_OPT_STRING, .help = "Preallocation mode (allowed values: off, full)" }, { .name = BLOCK_OPT_REDUNDANCY, .type = QEMU_OPT_STRING, .help = "Redundancy of the image" }, { .name = BLOCK_OPT_OBJECT_SIZE, .type = QEMU_OPT_SIZE, .help = "Object size of the image" }, { /* end of list */ } } }; static const char *const sd_strong_runtime_opts[] = { "vdi", "snap-id", "tag", "server.", NULL }; static BlockDriver bdrv_sheepdog = { .format_name = "sheepdog", .protocol_name = "sheepdog", .instance_size = sizeof(BDRVSheepdogState), .bdrv_parse_filename = sd_parse_filename, .bdrv_file_open = sd_open, .bdrv_reopen_prepare = sd_reopen_prepare, .bdrv_reopen_commit = sd_reopen_commit, .bdrv_reopen_abort = sd_reopen_abort, .bdrv_close = sd_close, .bdrv_co_create = sd_co_create, .bdrv_co_create_opts = sd_co_create_opts, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_getlength = sd_getlength, .bdrv_get_allocated_file_size = sd_get_allocated_file_size, .bdrv_co_truncate = sd_co_truncate, .bdrv_co_readv = sd_co_readv, .bdrv_co_writev = sd_co_writev, .bdrv_co_flush_to_disk = sd_co_flush_to_disk, .bdrv_co_pdiscard = sd_co_pdiscard, .bdrv_co_block_status = sd_co_block_status, .bdrv_snapshot_create = sd_snapshot_create, .bdrv_snapshot_goto = sd_snapshot_goto, .bdrv_snapshot_delete = sd_snapshot_delete, .bdrv_snapshot_list = sd_snapshot_list, .bdrv_save_vmstate = sd_save_vmstate, .bdrv_load_vmstate = sd_load_vmstate, .bdrv_detach_aio_context = sd_detach_aio_context, .bdrv_attach_aio_context = sd_attach_aio_context, .create_opts = &sd_create_opts, .strong_runtime_opts = sd_strong_runtime_opts, }; static BlockDriver bdrv_sheepdog_tcp = { .format_name = "sheepdog", .protocol_name = "sheepdog+tcp", .instance_size = sizeof(BDRVSheepdogState), .bdrv_parse_filename = sd_parse_filename, .bdrv_file_open = sd_open, .bdrv_reopen_prepare = sd_reopen_prepare, .bdrv_reopen_commit = sd_reopen_commit, .bdrv_reopen_abort = sd_reopen_abort, .bdrv_close = sd_close, .bdrv_co_create = sd_co_create, .bdrv_co_create_opts = sd_co_create_opts, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_getlength = sd_getlength, .bdrv_get_allocated_file_size = sd_get_allocated_file_size, .bdrv_co_truncate = sd_co_truncate, .bdrv_co_readv = sd_co_readv, .bdrv_co_writev = sd_co_writev, .bdrv_co_flush_to_disk = sd_co_flush_to_disk, .bdrv_co_pdiscard = sd_co_pdiscard, .bdrv_co_block_status = sd_co_block_status, .bdrv_snapshot_create = sd_snapshot_create, .bdrv_snapshot_goto = sd_snapshot_goto, .bdrv_snapshot_delete = sd_snapshot_delete, .bdrv_snapshot_list = sd_snapshot_list, .bdrv_save_vmstate = sd_save_vmstate, .bdrv_load_vmstate = sd_load_vmstate, .bdrv_detach_aio_context = sd_detach_aio_context, .bdrv_attach_aio_context = sd_attach_aio_context, .create_opts = &sd_create_opts, .strong_runtime_opts = sd_strong_runtime_opts, }; static BlockDriver bdrv_sheepdog_unix = { .format_name = "sheepdog", .protocol_name = "sheepdog+unix", .instance_size = sizeof(BDRVSheepdogState), .bdrv_parse_filename = sd_parse_filename, .bdrv_file_open = sd_open, .bdrv_reopen_prepare = sd_reopen_prepare, .bdrv_reopen_commit = sd_reopen_commit, .bdrv_reopen_abort = sd_reopen_abort, .bdrv_close = sd_close, .bdrv_co_create = sd_co_create, .bdrv_co_create_opts = sd_co_create_opts, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_getlength = sd_getlength, .bdrv_get_allocated_file_size = sd_get_allocated_file_size, .bdrv_co_truncate = sd_co_truncate, .bdrv_co_readv = sd_co_readv, .bdrv_co_writev = sd_co_writev, .bdrv_co_flush_to_disk = sd_co_flush_to_disk, .bdrv_co_pdiscard = sd_co_pdiscard, .bdrv_co_block_status = sd_co_block_status, .bdrv_snapshot_create = sd_snapshot_create, .bdrv_snapshot_goto = sd_snapshot_goto, .bdrv_snapshot_delete = sd_snapshot_delete, .bdrv_snapshot_list = sd_snapshot_list, .bdrv_save_vmstate = sd_save_vmstate, .bdrv_load_vmstate = sd_load_vmstate, .bdrv_detach_aio_context = sd_detach_aio_context, .bdrv_attach_aio_context = sd_attach_aio_context, .create_opts = &sd_create_opts, .strong_runtime_opts = sd_strong_runtime_opts, }; static void bdrv_sheepdog_init(void) { bdrv_register(&bdrv_sheepdog); bdrv_register(&bdrv_sheepdog_tcp); bdrv_register(&bdrv_sheepdog_unix); } block_init(bdrv_sheepdog_init);