@@ -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
new file mode 100644
@@ -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 <http://www.gnu.org/licenses/>.
+ */
+#include <netdb.h>
+#include <netinet/tcp.h>
+
+#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);
Sheepdog is a distributed storage system for QEMU. It provides highly available block level storage volumes to VMs like Amazon EBS. This patch adds a qemu block driver for Sheepdog. Sheepdog features are: - No node in the cluster is special (no metadata node, no control node, etc) - Linear scalability in performance and capacity - No single point of failure - Autonomous management (zero configuration) - Useful volume management support such as snapshot and cloning - Thin provisioning - Autonomous load balancing The more details are available at the project site: http://www.osrg.net/sheepdog/ Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> --- Changes from v4 to v5 are: - address the comments to the sheepdog driver (Thanks Kevin, Chris!) -- fix a coding style -- fix aio_cancel handling -- fix an overflow bug in coping hostname -- add comments to the non-trivial functions - remove already applied patches from the patchset Changes from v3 to v4 are: - fix error handling in bdrv_snapshot_goto. Changes from v2 to v3 are: - add drv->bdrv_close() and drv->bdrv_open() before and after bdrv_snapshot_goto() call of the protocol. - address the review comments on the sheepdog driver code. Changes from v1 to v2 are: - rebase onto git://repo.or.cz/qemu/kevin.git block - modify the sheepdog driver as a protocol driver - add new patch to call the snapshot handler of the protocol Makefile.objs | 2 +- block/sheepdog.c | 1905 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 1906 insertions(+), 1 deletions(-) create mode 100644 block/sheepdog.c