From patchwork Mon Jun 7 18:00:21 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: MORITA Kazutaka X-Patchwork-Id: 104791 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o57I3IsJ008545 for ; Mon, 7 Jun 2010 18:03:18 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752635Ab0FGSDP (ORCPT ); Mon, 7 Jun 2010 14:03:15 -0400 Received: from sh.osrg.net ([192.16.179.4]:43235 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751044Ab0FGSDN (ORCPT ); Mon, 7 Jun 2010 14:03:13 -0400 Received: from fs.osrg.net (postfix@fs.osrg.net [10.0.0.12]) by sh.osrg.net (8.14.3/8.14.3/OSRG-NET) with ESMTP id o57I2Tt8026949; Tue, 8 Jun 2010 03:02:30 +0900 Received: from localhost (dfs1401.osrg.net [10.68.14.1]) by fs.osrg.net (Postfix) with ESMTP id 1D75E3E0280; Tue, 8 Jun 2010 03:02:29 +0900 (JST) From: MORITA Kazutaka To: kwolf@redhat.com, chris.krumme@windriver.com Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, sheepdog@lists.wpkg.org Subject: [PATCH v5] block: add sheepdog driver for distributed storage support Date: Tue, 8 Jun 2010 03:00:21 +0900 Message-Id: <1275933621-404-1-git-send-email-morita.kazutaka@lab.ntt.co.jp> X-Mailer: git-send-email 1.5.6.5 X-Dispatcher: imput version 20070423(IM149) Lines: 1974 X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Mon, 07 Jun 2010 18:03:20 +0000 (UTC) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Tue, 08 Jun 2010 03:02:32 +0900 (JST) X-Virus-Scanned: clamav-milter 0.96 at sh X-Virus-Status: Clean Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org diff --git a/Makefile.objs b/Makefile.objs index 54dec26..070db8a 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -14,7 +14,7 @@ block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o block-nested-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o block-nested-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o -block-nested-y += parallels.o nbd.o blkdebug.o +block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o block-nested-$(CONFIG_WIN32) += raw-win32.o block-nested-$(CONFIG_POSIX) += raw-posix.o block-nested-$(CONFIG_CURL) += curl.o diff --git a/block/sheepdog.c b/block/sheepdog.c new file mode 100644 index 0000000..a9477a5 --- /dev/null +++ b/block/sheepdog.c @@ -0,0 +1,1905 @@ +/* + * 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 . + */ +#include +#include + +#include "qemu-common.h" +#include "qemu-error.h" +#include "block_int.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 + +#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_FLAG_CMD_WRITE 0x01 +#define SD_FLAG_CMD_COW 0x02 + +#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 */ + +/* + * 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 indentifier space + */ + +#define VDI_SPACE_SHIFT 32 +#define VDI_BIT (UINT64_C(1) << 63) +#define VMSTATE_BIT (UINT64_C(1) << 62) +#define MAX_DATA_OBJS (1ULL << 20) +#define MAX_CHILDREN 1024 +#define SD_MAX_VDI_LEN 256 +#define SD_NR_VDIS (1U << 24) +#define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22) +#define SECTOR_SIZE 512 + +#define SD_INODE_SIZE (sizeof(SheepdogInode)) +#define CURRENT_VDI_ID 0 + +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; + uint32_t copies; + uint32_t rsvd; + 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; + uint32_t copies; + 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; + uint32_t copies; + uint32_t snapid; + uint32_t pad[3]; +} 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 SheepdogInode { + char name[SD_MAX_VDI_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; + +/* + * 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 int is_data_obj_writeable(SheepdogInode *inode, unsigned int idx) +{ + return inode->vdi_id == inode->data_vdi_id[idx]; +} + +static inline int 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 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; +} + +#undef dprintf +#ifdef DEBUG_SDOG +#define dprintf(fmt, args...) \ + do { \ + fprintf(stdout, "%s %d: " fmt, __func__, __LINE__, ##args); \ + } while (0) +#else +#define dprintf(fmt, args...) +#endif + +#define min_t(type, x, y) ({ \ + type __min1 = (x); \ + type __min2 = (y); \ + __min1 < __min2 ? __min1: __min2; }) + +#define max_t(type, x, y) ({ \ + type __max1 = (x); \ + type __max2 = (y); \ + __max1 > __max2 ? __max1: __max2; }) + +typedef struct SheepdogAIOCB SheepdogAIOCB; + +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; + + QLIST_ENTRY(AIOReq) outstanding_aio_siblings; + QLIST_ENTRY(AIOReq) aioreq_siblings; +} AIOReq; + +enum AIOCBState { + AIOCB_WRITE_UDATA, + AIOCB_READ_UDATA, +}; + +struct SheepdogAIOCB { + BlockDriverAIOCB common; + + QEMUIOVector *qiov; + + int64_t sector_num; + int nb_sectors; + + int ret; + enum AIOCBState aiocb_type; + + QEMUBH *bh; + void (*aio_done_func)(SheepdogAIOCB *); + + int canceled; + + QLIST_HEAD(aioreq_head, AIOReq) aioreq_head; +}; + +typedef struct BDRVSheepdogState { + SheepdogInode inode; + + uint32_t min_dirty_data_idx; + uint32_t max_dirty_data_idx; + + char name[SD_MAX_VDI_LEN]; + int is_current; + + char *addr; + char *port; + int fd; + + uint32_t aioreq_seq_num; + QLIST_HEAD(outstanding_aio_head, AIOReq) outstanding_aio_head; +} BDRVSheepdogState; + +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"}, + }; + + 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 the sd_aio_readv/writev, read/write requests are added to the + * QEMU Bottom Halves. + * + * 2. In sd_readv_writev_bh_cb, the callbacks of BHs, we send the I/O + * requests to the server and link the requests to the + * outstanding_list in the BDRVSheepdogState. we exits the + * function without waiting for receiving the response. + * + * 3. We receive the response in aio_read_response, the fd handler to + * the sheepdog connection. If metadata update is needed, we send + * the write request to the vdi object in sd_write_done, the write + * completion function. The AIOCB callback is not called until all + * the requests belonging to the AIOCB are finished. + */ + +static inline AIOReq *alloc_aio_req(BDRVSheepdogState *s, SheepdogAIOCB *acb, + uint64_t oid, unsigned int data_len, + uint64_t offset, uint8_t flags, + uint64_t base_oid, unsigned int iov_offset) +{ + AIOReq *aio_req; + + aio_req = qemu_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++; + + QLIST_INSERT_HEAD(&s->outstanding_aio_head, aio_req, + outstanding_aio_siblings); + QLIST_INSERT_HEAD(&acb->aioreq_head, aio_req, aioreq_siblings); + + return aio_req; +} + +static inline int free_aio_req(BDRVSheepdogState *s, AIOReq *aio_req) +{ + SheepdogAIOCB *acb = aio_req->aiocb; + QLIST_REMOVE(aio_req, outstanding_aio_siblings); + QLIST_REMOVE(aio_req, aioreq_siblings); + qemu_free(aio_req); + + return !QLIST_EMPTY(&acb->aioreq_head); +} + +static void sd_finish_aiocb(SheepdogAIOCB *acb) +{ + if (!acb->canceled) { + acb->common.cb(acb->common.opaque, acb->ret); + } + qemu_aio_release(acb); +} + +static void sd_aio_cancel(BlockDriverAIOCB *blockacb) +{ + SheepdogAIOCB *acb = (SheepdogAIOCB *)blockacb; + + /* + * Sheepdog cannot cancel the requests which are already sent to + * the servers, so we just complete the request with -EIO here. + */ + acb->common.cb(acb->common.opaque, -EIO); + acb->canceled = 1; +} + +static AIOPool sd_aio_pool = { + .aiocb_size = sizeof(SheepdogAIOCB), + .cancel = sd_aio_cancel, +}; + +static SheepdogAIOCB *sd_aio_setup(BlockDriverState *bs, QEMUIOVector *qiov, + int64_t sector_num, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + SheepdogAIOCB *acb; + + acb = qemu_aio_get(&sd_aio_pool, bs, cb, opaque); + + acb->qiov = qiov; + + acb->sector_num = sector_num; + acb->nb_sectors = nb_sectors; + + acb->aio_done_func = NULL; + acb->canceled = 0; + acb->bh = NULL; + acb->ret = 0; + QLIST_INIT(&acb->aioreq_head); + return acb; +} + +static int sd_schedule_bh(QEMUBHFunc *cb, SheepdogAIOCB *acb) +{ + if (acb->bh) { + error_report("bug: %d %d\n", acb->aiocb_type, acb->aiocb_type); + return -EIO; + } + + acb->bh = qemu_bh_new(cb, acb); + if (!acb->bh) { + error_report("oom: %d %d\n", acb->aiocb_type, acb->aiocb_type); + return -EIO; + } + + qemu_bh_schedule(acb->bh); + + return 0; +} + +/* + * Send/recv data with iovec buffers + * + * This function send/recv data from/to the iovec buffer directly. + * The first `offset' bytes in the iovec buffer are skipped and next + * `len' bytes are used. + * + * For example, + * + * do_send_recv(sockfd, iov, len, offset, 1); + * + * is equals to + * + * char *buf = malloc(size); + * iov_to_buf(iov, iovcnt, buf, offset, size); + * send(sockfd, buf, size, 0); + * free(buf); + */ +static int do_send_recv(int sockfd, struct iovec *iov, int len, int offset, + int write) +{ + struct msghdr msg; + int ret, diff; + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + len += offset; + + while (iov->iov_len < len) { + len -= iov->iov_len; + + iov++; + msg.msg_iovlen++; + } + + diff = iov->iov_len - len; + iov->iov_len -= diff; + + while (msg.msg_iov->iov_len <= offset) { + offset -= msg.msg_iov->iov_len; + + msg.msg_iov++; + msg.msg_iovlen--; + } + + msg.msg_iov->iov_base = (char *) msg.msg_iov->iov_base + offset; + msg.msg_iov->iov_len -= offset; + + if (write) { + ret = sendmsg(sockfd, &msg, 0); + } else { + ret = recvmsg(sockfd, &msg, MSG_WAITALL); + } + + msg.msg_iov->iov_base = (char *) msg.msg_iov->iov_base - offset; + msg.msg_iov->iov_len += offset; + + iov->iov_len += diff; + return ret; +} + +static int connect_to_sdog(const char *addr, const char *port) +{ + char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; + int fd, ret; + struct addrinfo hints, *res, *res0; + + if (!addr) { + addr = SD_DEFAULT_ADDR; + port = SD_DEFAULT_PORT; + } + + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_STREAM; + + ret = getaddrinfo(addr, port, &hints, &res0); + if (ret) { + error_report("unable to get address info %s, %s\n", + addr, strerror(errno)); + return -1; + } + + for (res = res0; res; res = res->ai_next) { + ret = getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf), + sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV); + if (ret) { + continue; + } + + fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol); + if (fd < 0) { + continue; + } + + reconnect: + ret = connect(fd, res->ai_addr, res->ai_addrlen); + if (ret < 0) { + if (errno == EINTR) { + goto reconnect; + } + break; + } + + dprintf("connected to %s:%s\n", addr, port); + goto success; + } + fd = -1; + error_report("failed connect to %s:%s\n", addr, port); +success: + freeaddrinfo(res0); + return fd; +} + +static int do_readv_writev(int sockfd, struct iovec *iov, int len, + int iov_offset, int write) +{ + int ret; +again: + ret = do_send_recv(sockfd, iov, len, iov_offset, write); + if (ret < 0) { + if (errno == EINTR || errno == EAGAIN) { + goto again; + } + error_report("failed to recv a rsp, %s\n", strerror(errno)); + return 1; + } + + iov_offset += ret; + len -= ret; + if (len) { + goto again; + } + + return 0; +} + +static int do_readv(int sockfd, struct iovec *iov, int len, int iov_offset) +{ + return do_readv_writev(sockfd, iov, len, iov_offset, 0); +} + +static int do_writev(int sockfd, struct iovec *iov, int len, int iov_offset) +{ + return do_readv_writev(sockfd, iov, len, iov_offset, 1); +} + +static int do_read_write(int sockfd, void *buf, int len, int write) +{ + struct iovec iov; + + iov.iov_base = buf; + iov.iov_len = len; + + return do_readv_writev(sockfd, &iov, len, 0, write); +} + +static int do_read(int sockfd, void *buf, int len) +{ + return do_read_write(sockfd, buf, len, 0); +} + +static int do_write(int sockfd, void *buf, int len) +{ + return do_read_write(sockfd, buf, len, 1); +} + +static int send_req(int sockfd, SheepdogReq *hdr, void *data, + unsigned int *wlen) +{ + int ret; + struct iovec iov[2]; + + iov[0].iov_base = hdr; + iov[0].iov_len = sizeof(*hdr); + + if (*wlen) { + iov[1].iov_base = data; + iov[1].iov_len = *wlen; + } + + ret = do_writev(sockfd, iov, sizeof(*hdr) + *wlen, 0); + if (ret) { + error_report("failed to send a req, %s\n", strerror(errno)); + ret = -1; + } + + return ret; +} + +static int do_req(int sockfd, SheepdogReq *hdr, void *data, + unsigned int *wlen, unsigned int *rlen) +{ + int ret; + + ret = send_req(sockfd, hdr, data, wlen); + if (ret) { + ret = -1; + goto out; + } + + ret = do_read(sockfd, hdr, sizeof(*hdr)); + if (ret) { + error_report("failed to get a rsp, %s\n", strerror(errno)); + ret = -1; + goto out; + } + + if (*rlen > hdr->data_length) { + *rlen = hdr->data_length; + } + + if (*rlen) { + ret = do_read(sockfd, data, *rlen); + if (ret) { + error_report("failed to get the data, %s\n", strerror(errno)); + ret = -1; + goto out; + } + } + ret = 0; +out: + return ret; +} + +static int add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, + struct iovec *iov, int niov, int create, + enum AIOCBState aiocb_type); + +/* + * This function searchs pending requests to the object `oid', and + * sends them. + */ +static void send_pending_req(BDRVSheepdogState *s, uint64_t oid, uint32_t id) +{ + AIOReq *aio_req, *next; + SheepdogAIOCB *acb; + int ret; + + QLIST_FOREACH_SAFE(aio_req, &s->outstanding_aio_head, + outstanding_aio_siblings, next) { + if (id == aio_req->id) { + continue; + } + if (aio_req->oid != oid) { + continue; + } + + acb = aio_req->aiocb; + ret = add_aio_request(s, aio_req, acb->qiov->iov, + acb->qiov->niov, 0, acb->aiocb_type); + if (ret < 0) { + error_report("add_aio_request is failed\n"); + free_aio_req(s, aio_req); + if (QLIST_EMPTY(&acb->aioreq_head)) { + sd_finish_aiocb(acb); + } + } + } +} + +/* + * 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 aio_read_response(void *opaque) +{ + SheepdogObjRsp rsp; + BDRVSheepdogState *s = opaque; + int fd = s->fd; + int ret; + AIOReq *aio_req = NULL; + SheepdogAIOCB *acb; + int rest; + unsigned long idx; + + if (QLIST_EMPTY(&s->outstanding_aio_head)) { + return; + } + + /* read a header */ + ret = do_read(fd, &rsp, sizeof(rsp)); + if (ret) { + error_report("failed to get the header, %s\n", strerror(errno)); + return; + } + + /* find the right aio_req from the outstanding_aio list */ + QLIST_FOREACH(aio_req, &s->outstanding_aio_head, outstanding_aio_siblings) { + if (aio_req->id == rsp.id) { + break; + } + } + if (!aio_req) { + error_report("cannot find aio_req %x\n", rsp.id); + return; + } + + 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 (s->inode.data_vdi_id[idx] != s->inode.vdi_id) { + /* + * 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. + */ + s->inode.data_vdi_id[idx] = s->inode.vdi_id; + s->max_dirty_data_idx = max_t(uint32_t, idx, s->max_dirty_data_idx); + s->min_dirty_data_idx = min_t(uint32_t, idx, s->min_dirty_data_idx); + + /* + * Some requests may be blocked because simultaneous + * create requests are not allowed, so we search the + * pending requests here. + */ + send_pending_req(s, vid_to_data_oid(s->inode.vdi_id, idx), rsp.id); + } + break; + case AIOCB_READ_UDATA: + ret = do_readv(fd, acb->qiov->iov, rsp.data_length, + aio_req->iov_offset); + if (ret) { + error_report("failed to get the data, %s\n", strerror(errno)); + return; + } + break; + } + + if (rsp.result != SD_RES_SUCCESS) { + acb->ret = -EIO; + error_report("%s\n", sd_strerror(rsp.result)); + } + + rest = free_aio_req(s, aio_req); + if (!rest) { + /* + * We've finished all requests which belong to the AIOCB, so + * we can call the callback now. + */ + acb->aio_done_func(acb); + } +} + +static int aio_flush_request(void *opaque) +{ + BDRVSheepdogState *s = opaque; + + return !QLIST_EMPTY(&s->outstanding_aio_head); +} + +static int set_nonblocking(int fd) +{ + int ret; + + ret = fcntl(fd, F_GETFL); + if (ret < 0) { + error_report("can't fcntl (F_GETFL), %s\n", strerror(errno)); + close(fd); + } else { + ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK); + if (ret < 0) { + error_report("can't fcntl (O_NONBLOCK), %s\n", strerror(errno)); + } + } + + return ret; +} + +static int set_nodelay(int fd) +{ + int ret, opt; + + opt = 1; + ret = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)); + return ret; +} + +/* + * Return a socket discriptor to read/write objects. + * + * We cannot use this discriptor for other operations because + * the block driver may be on waiting response from the server. + */ +static int get_sheep_fd(BDRVSheepdogState *s) +{ + int ret, fd; + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + error_report("%s\n", strerror(errno)); + return -1; + } + + ret = set_nonblocking(fd); + if (ret) { + error_report("%s\n", strerror(errno)); + close(fd); + return -1; + } + + ret = set_nodelay(fd); + if (ret) { + error_report("%s\n", strerror(errno)); + close(fd); + return -1; + } + + qemu_aio_set_fd_handler(fd, aio_read_response, NULL, aio_flush_request, + NULL, s); + s->fd = fd; + + return fd; +} + +/* + * Parse a filename + * + * filename must be one of the following formats: + * 1. [vdiname] + * 2. [vdiname]:[snapid] + * 3. [hostname]:[port]:[vdiname] + * 4. [hostname]:[port]:[vdiname]:[snapid] + * + * You can boot from the snapshot images by specifying `snapid`. + * + * You can run VMs outside the Sheepdog cluster by specifying + * `hostname' and `port' (experimental). + */ +static int parse_vdiname(BDRVSheepdogState *s, const char *filename, + char *vdi, int vdi_len, uint32_t *snapid) +{ + char *p, *q; + int nr_sep; + + p = q = qemu_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 hostname and port number. */ + if (nr_sep >= 2) { + s->addr = p; + p = strchr(p, ':'); + *p++ = '\0'; + + s->port = p; + p = strchr(p, ':'); + *p++ = '\0'; + } else { + s->addr = NULL; + s->port = 0; + } + + strncpy(vdi, p, vdi_len); + + p = strchr(vdi, ':'); + if (p) { + *p++ = '\0'; + *snapid = strtoul(p, NULL, 10); + } else { + *snapid = CURRENT_VDI_ID; /* search current vdi */ + } + + if (s->addr == NULL) { + qemu_free(q); + } + + return 0; +} + +static int find_vdi_name(BDRVSheepdogState *s, char *filename, uint32_t snapid, + uint32_t *vid, int for_snapshot) +{ + int ret, fd; + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + unsigned int wlen, rlen = 0; + char buf[SD_MAX_VDI_LEN]; + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + return -1; + } + + memset(&hdr, 0, sizeof(hdr)); + snprintf(buf, sizeof(buf), "%s", filename); + if (for_snapshot) { + hdr.opcode = SD_OP_GET_VDI_INFO; + } else { + hdr.opcode = SD_OP_LOCK_VDI; + } + wlen = SD_MAX_VDI_LEN; + hdr.proto_ver = SD_PROTO_VER; + hdr.data_length = SD_MAX_VDI_LEN; + hdr.snapid = snapid; + hdr.flags = SD_FLAG_CMD_WRITE; + + ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + if (ret) { + ret = -1; + goto out; + } + + if (rsp->result != SD_RES_SUCCESS) { + error_report("%s, %s\n", sd_strerror(rsp->result), filename); + ret = -1; + goto out; + } + *vid = rsp->vdi_id; + + ret = 0; +out: + close(fd); + return ret; +} + +static int add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, + struct iovec *iov, int niov, int create, + enum AIOCBState aiocb_type) +{ + int nr_copies = s->inode.nr_copies; + SheepdogObjReq hdr; + unsigned int wlen; + int ret, opt; + 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; + + if (!nr_copies) { + error_report("bug\n"); + } + + memset(&hdr, 0, sizeof(hdr)); + + if (aiocb_type == AIOCB_READ_UDATA) { + wlen = 0; + hdr.opcode = SD_OP_READ_OBJ; + hdr.flags = flags; + } else if (create) { + wlen = datalen; + hdr.opcode = SD_OP_CREATE_AND_WRITE_OBJ; + hdr.flags = SD_FLAG_CMD_WRITE | flags; + } else { + wlen = datalen; + hdr.opcode = SD_OP_WRITE_OBJ; + hdr.flags = SD_FLAG_CMD_WRITE | 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; + + opt = 1; + setsockopt(s->fd, SOL_TCP, TCP_CORK, &opt, sizeof(opt)); + + /* send a header */ + ret = do_write(s->fd, &hdr, sizeof(hdr)); + if (ret) { + error_report("failed to send a req, %s\n", strerror(errno)); + return -EIO; + } + + if (wlen) { + ret = do_writev(s->fd, iov, wlen, aio_req->iov_offset); + if (ret) { + error_report("failed to send a data, %s\n", strerror(errno)); + return -EIO; + } + } + opt = 0; + setsockopt(s->fd, SOL_TCP, TCP_CORK, &opt, sizeof(opt)); + + return 0; +} + +static int read_write_object(int fd, char *buf, uint64_t oid, int copies, + unsigned int datalen, uint64_t offset, + int write, int create) +{ + 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.oid = oid; + hdr.data_length = datalen; + hdr.offset = offset; + hdr.copies = copies; + + ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + if (ret) { + error_report("failed to send a request to the sheep\n"); + return -1; + } + + switch (rsp->result) { + case SD_RES_SUCCESS: + return 0; + default: + error_report("%s\n", sd_strerror(rsp->result)); + return -1; + } +} + +static int read_object(int fd, char *buf, uint64_t oid, int copies, + unsigned int datalen, uint64_t offset) +{ + return read_write_object(fd, buf, oid, copies, datalen, offset, 0, 0); +} + +static int write_object(int fd, char *buf, uint64_t oid, int copies, + unsigned int datalen, uint64_t offset, int create) +{ + return read_write_object(fd, buf, oid, copies, datalen, offset, 1, create); +} + +static int sd_open(BlockDriverState *bs, const char *filename, int flags) +{ + int ret, fd; + uint32_t vid = 0; + BDRVSheepdogState *s = bs->opaque; + char vdi[SD_MAX_VDI_LEN]; + uint32_t snapid; + char *buf; + + strstart(filename, "sheepdog:", (const char **)&filename); + + buf = qemu_malloc(SD_INODE_SIZE); + + memset(vdi, 0, sizeof(vdi)); + if (parse_vdiname(s, filename, vdi, sizeof(vdi), &snapid) < 0) { + goto out; + } + s->fd = get_sheep_fd(s); + if (s->fd < 0) { + goto out; + } + + ret = find_vdi_name(s, vdi, snapid, &vid, 0); + if (ret) { + goto out; + } + + if (snapid) { + dprintf("%" PRIx32 " non current inode was open.\n", vid); + } else { + s->is_current = 1; + } + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + error_report("failed to connect\n"); + goto out; + } + + ret = read_object(fd, buf, vid_to_vdi_oid(vid), 0, SD_INODE_SIZE, 0); + + close(fd); + + if (ret) { + goto out; + } + + memcpy(&s->inode, buf, sizeof(s->inode)); + s->min_dirty_data_idx = UINT32_MAX; + s->max_dirty_data_idx = 0; + + bs->total_sectors = s->inode.vdi_size >> 9; + strncpy(s->name, vdi, sizeof(s->name)); + qemu_free(buf); + + QLIST_INIT(&s->outstanding_aio_head); + return 0; +out: + qemu_free(buf); + return -1; +} + +static int do_sd_create(char *filename, char *tag, int64_t total_sectors, + uint32_t base_vid, uint32_t *vdi_id, int snapshot, + const char *addr, const char *port) +{ + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + int fd, ret; + unsigned int wlen, rlen = 0; + char buf[SD_MAX_VDI_LEN]; + + fd = connect_to_sdog(addr, port); + if (fd < 0) { + return -1; + } + + strncpy(buf, filename, SD_MAX_VDI_LEN); + + memset(&hdr, 0, sizeof(hdr)); + hdr.opcode = SD_OP_NEW_VDI; + hdr.base_vdi_id = base_vid; + + wlen = SD_MAX_VDI_LEN; + + hdr.flags = SD_FLAG_CMD_WRITE; + hdr.snapid = snapshot; + + hdr.data_length = wlen; + hdr.vdi_size = total_sectors * SECTOR_SIZE; + + ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + + close(fd); + + if (ret) { + return -1; + } + + if (rsp->result != SD_RES_SUCCESS) { + error_report("%s, %s\n", sd_strerror(rsp->result), filename); + return -1; + } + + if (vdi_id) { + *vdi_id = rsp->vdi_id; + } + + return 0; +} + +static int sd_create(const char *filename, QEMUOptionParameter *options) +{ + int ret; + uint32_t vid = 0; + int64_t total_sectors = 0; + char *backing_file = NULL; + + strstart(filename, "sheepdog:", (const char **)&filename); + + while (options && options->name) { + if (!strcmp(options->name, BLOCK_OPT_SIZE)) { + total_sectors = options->value.n / SECTOR_SIZE; + } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { + backing_file = options->value.s; + } + options++; + } + + if (backing_file) { + BlockDriverState *bs; + BDRVSheepdogState *s; + BlockDriver *drv; + + /* Currently, only Sheepdog backing image is supported. */ + drv = bdrv_find_protocol(backing_file); + if (!drv || strcmp(drv->protocol_name, "sheepdog") != 0) { + error_report("backing_file must be a sheepdog image\n"); + return -EINVAL; + } + + ret = bdrv_file_open(&bs, backing_file, 0); + if (ret < 0) + return -EIO; + + s = bs->opaque; + + if (!s->inode.snap_ctime) { + error_report("cannot clone from a current vdi\n"); + bdrv_delete(bs); + return -EINVAL; + } + + vid = s->inode.vdi_id; + bdrv_delete(bs); + } + + return do_sd_create((char *)filename, NULL, total_sectors, vid, NULL, 0, + NULL, NULL); +} + +static void sd_close(BlockDriverState *bs) +{ + BDRVSheepdogState *s = bs->opaque; + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + unsigned int wlen, rlen = 0; + int fd, ret; + + dprintf("%s\n", s->name); + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + return; + } + + memset(&hdr, 0, sizeof(hdr)); + + hdr.opcode = SD_OP_RELEASE_VDI; + wlen = strlen(s->name) + 1; + hdr.data_length = wlen; + hdr.flags = SD_FLAG_CMD_WRITE; + + ret = do_req(fd, (SheepdogReq *)&hdr, s->name, &wlen, &rlen); + + close(fd); + + if (!ret && rsp->result != SD_RES_SUCCESS && + rsp->result != SD_RES_VDI_NOT_LOCKED) { + error_report("%s, %s\n", sd_strerror(rsp->result), s->name); + } + + close(s->fd); + qemu_free(s->addr); +} + +/* + * This function is called after writing data objects. If we need to + * update metadata, this sends a write request to the vdi object. + * Otherwise, this calls the AIOCB callback. + */ +static void sd_write_done(SheepdogAIOCB *acb) +{ + int ret; + BDRVSheepdogState *s = acb->common.bs->opaque; + struct iovec iov; + AIOReq *aio_req; + uint32_t offset, data_len, mn, mx; + + mn = s->min_dirty_data_idx; + mx = s->max_dirty_data_idx; + if (mn <= mx) { + /* we need to update the vdi object. */ + 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]); + + s->min_dirty_data_idx = UINT32_MAX; + s->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, 0, offset); + ret = add_aio_request(s, aio_req, &iov, 1, 0, AIOCB_WRITE_UDATA); + if (ret) { + free_aio_req(s, aio_req); + acb->ret = -EIO; + goto out; + } + + acb->aio_done_func = sd_finish_aiocb; + acb->aiocb_type = AIOCB_WRITE_UDATA; + return; + } +out: + sd_finish_aiocb(acb); +} + +/* + * Create a writable VDI from a snapshot + */ +static int sd_create_branch(BDRVSheepdogState *s) +{ + int ret, fd; + uint32_t vid; + char *buf; + + dprintf("%" PRIx32 " is not current.\n", s->inode.vdi_id); + + buf = qemu_malloc(SD_INODE_SIZE); + + ret = do_sd_create(s->name, NULL, s->inode.vdi_size >> 9, + s->inode.vdi_id, &vid, 1, s->addr, s->port); + if (ret) { + goto out; + } + + dprintf("%" PRIx32 " is created.\n", vid); + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + error_report("failed to connect\n"); + goto out; + } + + ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies, + SD_INODE_SIZE, 0); + + close(fd); + + if (ret < 0) { + goto out; + } + + memcpy(&s->inode, buf, sizeof(s->inode)); + + s->is_current = 1; + ret = 0; + dprintf("%" PRIx32 " was newly created.\n", s->inode.vdi_id); + +out: + qemu_free(buf); + + return ret; +} + +/* + * Send I/O requests to the server. + * + * This function sends requests to the server, links the requests to + * the outstanding_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. + */ +static void sd_readv_writev_bh_cb(void *p) +{ + SheepdogAIOCB *acb = p; + int ret = 0; + unsigned long len, done = 0, total = acb->nb_sectors * SECTOR_SIZE; + unsigned long idx = acb->sector_num * SECTOR_SIZE / SD_DATA_OBJ_SIZE; + uint64_t oid; + uint64_t offset = (acb->sector_num * SECTOR_SIZE) % SD_DATA_OBJ_SIZE; + BDRVSheepdogState *s = acb->common.bs->opaque; + SheepdogInode *inode = &s->inode; + AIOReq *aio_req; + + qemu_bh_delete(acb->bh); + acb->bh = NULL; + + if (acb->aiocb_type == AIOCB_WRITE_UDATA && !s->is_current) { + /* + * 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; + goto out; + } + } + + while (done != total) { + uint8_t flags = 0; + uint64_t old_oid = 0; + int create = 0; + + oid = vid_to_data_oid(inode->data_vdi_id[idx], idx); + + len = min_t(unsigned long, total - done, SD_DATA_OBJ_SIZE - offset); + + if (!inode->data_vdi_id[idx]) { + if (acb->aiocb_type == AIOCB_READ_UDATA) { + goto done; + } + + create = 1; + } else if (acb->aiocb_type == AIOCB_WRITE_UDATA + && !is_data_obj_writeable(inode, idx)) { + /* Copy-On-Write */ + create = 1; + old_oid = oid; + flags = SD_FLAG_CMD_COW; + } + + if (create) { + dprintf("update ino (%" PRIu32") %" PRIu64 " %" PRIu64 + " %" PRIu64 "\n", inode->vdi_id, oid, + vid_to_data_oid(inode->data_vdi_id[idx], idx), idx); + oid = vid_to_data_oid(inode->vdi_id, idx); + dprintf("new oid %lx\n", oid); + } + + aio_req = alloc_aio_req(s, acb, oid, len, offset, flags, old_oid, done); + + if (create) { + AIOReq *areq; + QLIST_FOREACH(areq, &s->outstanding_aio_head, + outstanding_aio_siblings) { + if (areq == aio_req) { + continue; + } + if (areq->oid == oid) { + /* + * Sheepdog cannot handle simultaneous create + * requests to the same object. So we cannot send + * the request until the previous request + * finishes. + */ + aio_req->flags = 0; + aio_req->base_oid = 0; + goto done; + } + } + } + + ret = add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, + create, acb->aiocb_type); + if (ret < 0) { + error_report("add_aio_request is failed\n"); + free_aio_req(s, aio_req); + acb->ret = -EIO; + goto out; + } + done: + offset = 0; + idx++; + done += len; + } +out: + if (QLIST_EMPTY(&acb->aioreq_head)) { + sd_finish_aiocb(acb); + } +} + +static BlockDriverAIOCB *sd_aio_writev(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + SheepdogAIOCB *acb; + + acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors, cb, opaque); + acb->aio_done_func = sd_write_done; + acb->aiocb_type = AIOCB_WRITE_UDATA; + + sd_schedule_bh(sd_readv_writev_bh_cb, acb); + return &acb->common; +} + +static BlockDriverAIOCB *sd_aio_readv(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + SheepdogAIOCB *acb; + int i; + + acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors, cb, opaque); + acb->aiocb_type = AIOCB_READ_UDATA; + acb->aio_done_func = sd_finish_aiocb; + + /* + * TODO: we can do better; we don't need to initialize + * blindly. + */ + for (i = 0; i < qiov->niov; i++) { + memset(qiov->iov[i].iov_base, 0, qiov->iov[i].iov_len); + } + + sd_schedule_bh(sd_readv_writev_bh_cb, acb); + return &acb->common; +} + +static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) +{ + BDRVSheepdogState *s = bs->opaque; + int ret, fd; + uint32_t new_vid; + SheepdogInode *inode; + unsigned int datalen; + uint64_t offset; + + dprintf("sn_info: name %s id_str %s s: name %s vm_state_size %d " + "is_current %d\n", sn_info->name, sn_info->id_str, + s->name, sn_info->vm_state_size, s->is_current); + + if (!s->is_current) { + error_report("You can't create a snapshot of a non current VDI, " + "%s (%" PRIu32 ").\n", s->name, s->inode.vdi_id); + + return -EINVAL; + } + + dprintf("%s %s\n", 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; + offset = 0; + /* we don't need to read entire object */ + datalen = SD_INODE_SIZE - sizeof(s->inode.data_vdi_id); + + /* refresh inode. */ + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + ret = -EIO; + goto cleanup; + } + + ret = write_object(fd, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id), + s->inode.nr_copies, datalen, offset, 0); + if (ret < 0) { + error_report("failed to write snapshot's inode.\n"); + ret = -EIO; + goto cleanup; + } + + ret = do_sd_create(s->name, NULL, s->inode.vdi_size >> 9, + s->inode.vdi_id, &new_vid, 1, s->addr, s->port); + if (ret < 0) { + error_report("failed to create inode for snapshot. %s\n", + strerror(errno)); + ret = -EIO; + goto cleanup; + } + + inode = (SheepdogInode *)qemu_malloc(datalen); + + ret = read_object(fd, (char *)inode, vid_to_vdi_oid(new_vid), + s->inode.nr_copies, datalen, offset); + + if (ret < 0) { + error_report("failed to read new inode info. %s\n", strerror(errno)); + ret = -EIO; + goto cleanup; + } + + memcpy(&s->inode, inode, datalen); + dprintf("s->inode: name %s snap_id %x oid %x\n", + s->inode.name, s->inode.snap_id, s->inode.vdi_id); + +cleanup: + close(fd); + return ret; +} + +static int sd_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) +{ + BDRVSheepdogState *s = bs->opaque; + BDRVSheepdogState *old_s; + char vdi[SD_MAX_VDI_LEN]; + char *buf = NULL; + uint32_t vid; + uint32_t snapid = 0; + int ret = -ENOENT, fd; + + old_s = qemu_malloc(sizeof(BDRVSheepdogState)); + + memcpy(old_s, s, sizeof(BDRVSheepdogState)); + + snapid = strtoul(snapshot_id, NULL, 10); + if (!snapid) { + error_report("Invalid snapshot_id\n"); + goto out; + } + + buf = qemu_malloc(SD_INODE_SIZE); + strncpy(vdi, s->name, sizeof(vdi)); + ret = find_vdi_name(s, vdi, snapid, &vid, 1); + if (ret) { + error_report("Failed to find_vdi_name\n"); + ret = -ENOENT; + goto out; + } + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + error_report("failed to connect\n"); + goto out; + } + + ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies, + SD_INODE_SIZE, 0); + + close(fd); + + if (ret) { + ret = -ENOENT; + goto out; + } + + memcpy(&s->inode, buf, sizeof(s->inode)); + + if (!s->inode.vm_state_size) { + error_report("Invalid snapshot\n"); + ret = -ENOENT; + goto out; + } + + s->is_current = 0; + + qemu_free(buf); + qemu_free(old_s); + + return 0; +out: + /* recover bdrv_sd_state */ + memcpy(s, old_s, sizeof(BDRVSheepdogState)); + qemu_free(buf); + qemu_free(old_s); + + error_report("failed to open. recover old bdrv_sd_state.\n"); + + return ret; +} + +static int sd_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) +{ + /* FIXME: Delete specified snapshot id. */ + return 0; +} + +#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) +#define BITS_PER_BYTE 8 +#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) +#define DECLARE_BITMAP(name,bits) \ + unsigned long name[BITS_TO_LONGS(bits)] + +#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long)) + +static inline int test_bit(unsigned int nr, const unsigned long *addr) +{ + return ((1UL << (nr % BITS_PER_LONG)) & + (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; +} + +static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) +{ + BDRVSheepdogState *s = bs->opaque; + SheepdogReq req; + int i, fd, nr = 1024, ret, max = BITS_TO_LONGS(SD_NR_VDIS) * sizeof(long); + QEMUSnapshotInfo *sn_tab = NULL; + unsigned wlen, rlen; + int found = 0; + static SheepdogInode inode; + unsigned long *vdi_inuse; + unsigned int start_nr; + uint64_t hval; + + vdi_inuse = qemu_malloc(max); + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + 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, (SheepdogReq *)&req, vdi_inuse, &wlen, &rlen); + + close(fd); + if (ret) { + goto out; + } + + sn_tab = qemu_mallocz(nr * sizeof(*sn_tab)); + + /* 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->addr, s->port); + if (fd < 0) { + error_report("failed to connect\n"); + goto out; + } + + /* TODO: round up */ + for (i = start_nr; i < SD_NR_VDIS && found < nr; i++) { + if (!test_bit(i, vdi_inuse)) { + break; + } + + /* we don't need to read entire object */ + ret = read_object(fd, (char *)&inode, vid_to_vdi_oid(i), + 0, SD_INODE_SIZE - sizeof(inode.data_vdi_id), 0); + + if (ret) { + continue; + } + + if (!strcmp(inode.name, s->name) && inode.snap_ctime) { + 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), "%u", + inode.snap_id); + found++; + } + } + + close(fd); +out: + *psn_tab = sn_tab; + + qemu_free(vdi_inuse); + + return found; +} + +static int do_load_save_vmstate(BDRVSheepdogState *s, uint8_t *data, + int64_t pos, int size, int load) +{ + int fd, create; + int ret = 0; + unsigned int data_len; + uint64_t vmstate_oid; + uint32_t vdi_index; + uint64_t offset; + + fd = connect_to_sdog(s->addr, s->port); + if (fd < 0) { + ret = -EIO; + goto cleanup; + } + + while (size) { + vdi_index = pos / SD_DATA_OBJ_SIZE; + offset = pos % SD_DATA_OBJ_SIZE; + + data_len = min_t(unsigned int, size, SD_DATA_OBJ_SIZE); + + vmstate_oid = vid_to_vmstate_oid(s->inode.vdi_id, vdi_index); + + create = (offset == 0); + if (load) { + ret = read_object(fd, (char *)data, vmstate_oid, + s->inode.nr_copies, data_len, offset); + } else { + ret = write_object(fd, (char *)data, vmstate_oid, + s->inode.nr_copies, data_len, offset, create); + } + + if (ret < 0) { + error_report("failed to save vmstate %s\n", strerror(errno)); + ret = -EIO; + goto cleanup; + } + + pos += data_len; + size -= data_len; + ret += data_len; + } +cleanup: + close(fd); + return ret; +} + +static int sd_save_vmstate(BlockDriverState *bs, const uint8_t *data, + int64_t pos, int size) +{ + BDRVSheepdogState *s = bs->opaque; + + return do_load_save_vmstate(s, (uint8_t *)data, pos, size, 0); +} + +static int sd_load_vmstate(BlockDriverState *bs, uint8_t *data, + int64_t pos, int size) +{ + BDRVSheepdogState *s = bs->opaque; + + return do_load_save_vmstate(s, data, pos, size, 1); +} + + +static QEMUOptionParameter sd_create_options[] = { + { + .name = BLOCK_OPT_SIZE, + .type = OPT_SIZE, + .help = "Virtual disk size" + }, + { + .name = BLOCK_OPT_BACKING_FILE, + .type = OPT_STRING, + .help = "File name of a base image" + }, + { NULL } +}; + +BlockDriver bdrv_sheepdog = { + .format_name = "sheepdog", + .protocol_name = "sheepdog", + .instance_size = sizeof(BDRVSheepdogState), + .bdrv_file_open = sd_open, + .bdrv_close = sd_close, + .bdrv_create = sd_create, + + .bdrv_aio_readv = sd_aio_readv, + .bdrv_aio_writev = sd_aio_writev, + + .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, + + .create_options = sd_create_options, +}; + +static void bdrv_sheepdog_init(void) +{ + bdrv_register(&bdrv_sheepdog); +} +block_init(bdrv_sheepdog_init);