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qemu/block/sheepdog.c
MORITA Kazutaka 2df4624662 sheepdog: use coroutines 
This makes the sheepdog block driver support bdrv_co_readv/writev
instead of bdrv_aio_readv/writev.

With this patch, Sheepdog network I/O becomes fully asynchronous.  The
block driver yields back when send/recv returns EAGAIN, and is resumed
when the sheepdog network connection is ready for the operation.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-24 14:53:51 +02:00

2120 lines
54 KiB
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/*
* 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 "qemu-common.h"
#include "qemu-error.h"
#include "qemu_socket.h"
#include "block_int.h"
#include "bitops.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 (UINT64_C(1) << 20)
#define MAX_CHILDREN 1024
#define SD_MAX_VDI_LEN 256
#define SD_MAX_VDI_TAG_LEN 256
#define SD_NR_VDIS (1U << 24)
#define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22)
#define SD_MAX_VDI_SIZE (SD_DATA_OBJ_SIZE * MAX_DATA_OBJS)
#define 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];
char tag[SD_MAX_VDI_TAG_LEN];
uint64_t ctime;
uint64_t snap_ctime;
uint64_t vm_clock_nsec;
uint64_t vdi_size;
uint64_t vm_state_size;
uint16_t copy_policy;
uint8_t nr_copies;
uint8_t block_size_shift;
uint32_t snap_id;
uint32_t vdi_id;
uint32_t parent_vdi_id;
uint32_t child_vdi_id[MAX_CHILDREN];
uint32_t data_vdi_id[MAX_DATA_OBJS];
} SheepdogInode;
/*
* 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_writable(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;
}
static inline int is_snapshot(struct SheepdogInode *inode)
{
return !!inode->snap_ctime;
}
#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
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;
Coroutine *coroutine;
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_snapshot;
char *addr;
char *port;
int fd;
CoMutex lock;
Coroutine *co_send;
Coroutine *co_recv;
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 sd_co_rw_vector, we send the I/O requests to the server and
* link the requests to the outstanding_list in the
* BDRVSheepdogState. The function exits without waiting for
* receiving the response.
*
* 2. 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. We switch back to sd_co_readv/writev after
* 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 = g_malloc(sizeof(*aio_req));
aio_req->aiocb = acb;
aio_req->iov_offset = iov_offset;
aio_req->oid = oid;
aio_req->base_oid = base_oid;
aio_req->offset = offset;
aio_req->data_len = data_len;
aio_req->flags = flags;
aio_req->id = s->aioreq_seq_num++;
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);
g_free(aio_req);
return !QLIST_EMPTY(&acb->aioreq_head);
}
static void sd_finish_aiocb(SheepdogAIOCB *acb)
{
if (!acb->canceled) {
qemu_coroutine_enter(acb->coroutine, NULL);
}
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->ret = -EIO;
qemu_coroutine_enter(acb->coroutine, NULL);
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->coroutine = qemu_coroutine_self();
acb->ret = 0;
QLIST_INIT(&acb->aioreq_head);
return acb;
}
#ifdef _WIN32
struct msghdr {
struct iovec *msg_iov;
size_t msg_iovlen;
};
static ssize_t sendmsg(int s, const struct msghdr *msg, int flags)
{
size_t size = 0;
char *buf, *p;
int i, ret;
/* count the msg size */
for (i = 0; i < msg->msg_iovlen; i++) {
size += msg->msg_iov[i].iov_len;
}
buf = g_malloc(size);
p = buf;
for (i = 0; i < msg->msg_iovlen; i++) {
memcpy(p, msg->msg_iov[i].iov_base, msg->msg_iov[i].iov_len);
p += msg->msg_iov[i].iov_len;
}
ret = send(s, buf, size, flags);
g_free(buf);
return ret;
}
static ssize_t recvmsg(int s, struct msghdr *msg, int flags)
{
size_t size = 0;
char *buf, *p;
int i, ret;
/* count the msg size */
for (i = 0; i < msg->msg_iovlen; i++) {
size += msg->msg_iov[i].iov_len;
}
buf = g_malloc(size);
ret = qemu_recv(s, buf, size, flags);
if (ret < 0) {
goto out;
}
p = buf;
for (i = 0; i < msg->msg_iovlen; i++) {
memcpy(msg->msg_iov[i].iov_base, p, msg->msg_iov[i].iov_len);
p += msg->msg_iov[i].iov_len;
}
out:
g_free(buf);
return ret;
}
#endif
/*
* 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, 0);
}
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",
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", 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) {
goto again;
}
if (errno == EAGAIN) {
if (qemu_in_coroutine()) {
qemu_coroutine_yield();
}
goto again;
}
error_report("failed to recv a rsp, %s", 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", 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", 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", 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");
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)) {
goto out;
}
/* read a header */
ret = do_read(fd, &rsp, sizeof(rsp));
if (ret) {
error_report("failed to get the header, %s", strerror(errno));
goto out;
}
/* 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", rsp.id);
goto out;
}
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(idx, s->max_dirty_data_idx);
s->min_dirty_data_idx = MIN(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", strerror(errno));
goto out;
}
break;
}
if (rsp.result != SD_RES_SUCCESS) {
acb->ret = -EIO;
error_report("%s", 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 switch back to sd_co_readv/writev now.
*/
acb->aio_done_func(acb);
}
out:
s->co_recv = NULL;
}
static void co_read_response(void *opaque)
{
BDRVSheepdogState *s = opaque;
if (!s->co_recv) {
s->co_recv = qemu_coroutine_create(aio_read_response);
}
qemu_coroutine_enter(s->co_recv, opaque);
}
static void co_write_request(void *opaque)
{
BDRVSheepdogState *s = opaque;
qemu_coroutine_enter(s->co_send, NULL);
}
static int aio_flush_request(void *opaque)
{
BDRVSheepdogState *s = opaque;
return !QLIST_EMPTY(&s->outstanding_aio_head);
}
#if !defined(SOL_TCP) || !defined(TCP_CORK)
static int set_cork(int fd, int v)
{
return 0;
}
#else
static int set_cork(int fd, int v)
{
return setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
}
#endif
static int set_nodelay(int fd)
{
int ret, opt;
opt = 1;
ret = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *)&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", strerror(errno));
return -1;
}
socket_set_nonblock(fd);
ret = set_nodelay(fd);
if (ret) {
error_report("%s", strerror(errno));
closesocket(fd);
return -1;
}
qemu_aio_set_fd_handler(fd, co_read_response, NULL, aio_flush_request,
NULL, s);
return fd;
}
/*
* Parse a filename
*
* filename must be one of the following formats:
* 1. [vdiname]
* 2. [vdiname]:[snapid]
* 3. [vdiname]:[tag]
* 4. [hostname]:[port]:[vdiname]
* 5. [hostname]:[port]:[vdiname]:[snapid]
* 6. [hostname]:[port]:[vdiname]:[tag]
*
* You can boot from the snapshot images by specifying `snapid` or
* `tag'.
*
* You can run VMs outside the Sheepdog cluster by specifying
* `hostname' and `port' (experimental).
*/
static int parse_vdiname(BDRVSheepdogState *s, const char *filename,
char *vdi, uint32_t *snapid, char *tag)
{
char *p, *q;
int nr_sep;
p = q = g_strdup(filename);
/* count the number of separators */
nr_sep = 0;
while (*p) {
if (*p == ':') {
nr_sep++;
}
p++;
}
p = q;
/* use the first two tokens as 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, SD_MAX_VDI_LEN);
p = strchr(vdi, ':');
if (p) {
*p++ = '\0';
*snapid = strtoul(p, NULL, 10);
if (*snapid == 0) {
strncpy(tag, p, SD_MAX_VDI_TAG_LEN);
}
} else {
*snapid = CURRENT_VDI_ID; /* search current vdi */
}
if (s->addr == NULL) {
g_free(q);
}
return 0;
}
static int find_vdi_name(BDRVSheepdogState *s, char *filename, uint32_t snapid,
char *tag, 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 + SD_MAX_VDI_TAG_LEN];
fd = connect_to_sdog(s->addr, s->port);
if (fd < 0) {
return -1;
}
memset(buf, 0, sizeof(buf));
strncpy(buf, filename, SD_MAX_VDI_LEN);
strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);
memset(&hdr, 0, sizeof(hdr));
if (for_snapshot) {
hdr.opcode = SD_OP_GET_VDI_INFO;
} else {
hdr.opcode = SD_OP_LOCK_VDI;
}
wlen = SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN;
hdr.proto_ver = SD_PROTO_VER;
hdr.data_length = wlen;
hdr.snapid = snapid;
hdr.flags = SD_FLAG_CMD_WRITE;
ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen);
if (ret) {
ret = -1;
goto out;
}
if (rsp->result != SD_RES_SUCCESS) {
error_report("cannot get vdi info, %s, %s %d %s",
sd_strerror(rsp->result), filename, snapid, tag);
ret = -1;
goto out;
}
*vid = rsp->vdi_id;
ret = 0;
out:
closesocket(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;
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");
}
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;
qemu_co_mutex_lock(&s->lock);
s->co_send = qemu_coroutine_self();
qemu_aio_set_fd_handler(s->fd, co_read_response, co_write_request,
aio_flush_request, NULL, s);
set_cork(s->fd, 1);
/* send a header */
ret = do_write(s->fd, &hdr, sizeof(hdr));
if (ret) {
error_report("failed to send a req, %s", 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", strerror(errno));
return -EIO;
}
}
set_cork(s->fd, 0);
qemu_aio_set_fd_handler(s->fd, co_read_response, NULL,
aio_flush_request, NULL, s);
qemu_co_mutex_unlock(&s->lock);
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");
return -1;
}
switch (rsp->result) {
case SD_RES_SUCCESS:
return 0;
default:
error_report("%s", 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], tag[SD_MAX_VDI_TAG_LEN];
uint32_t snapid;
char *buf = NULL;
strstart(filename, "sheepdog:", (const char **)&filename);
QLIST_INIT(&s->outstanding_aio_head);
s->fd = -1;
memset(vdi, 0, sizeof(vdi));
memset(tag, 0, sizeof(tag));
if (parse_vdiname(s, filename, vdi, &snapid, tag) < 0) {
goto out;
}
s->fd = get_sheep_fd(s);
if (s->fd < 0) {
goto out;
}
ret = find_vdi_name(s, vdi, snapid, tag, &vid, 0);
if (ret) {
goto out;
}
if (snapid) {
dprintf("%" PRIx32 " snapshot inode was open.\n", vid);
s->is_snapshot = 1;
}
fd = connect_to_sdog(s->addr, s->port);
if (fd < 0) {
error_report("failed to connect");
goto out;
}
buf = g_malloc(SD_INODE_SIZE);
ret = read_object(fd, buf, vid_to_vdi_oid(vid), 0, SD_INODE_SIZE, 0);
closesocket(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 / SECTOR_SIZE;
strncpy(s->name, vdi, sizeof(s->name));
qemu_co_mutex_init(&s->lock);
g_free(buf);
return 0;
out:
qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL, NULL, NULL);
if (s->fd >= 0) {
closesocket(s->fd);
}
g_free(buf);
return -1;
}
static int do_sd_create(char *filename, int64_t vdi_size,
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 -EIO;
}
memset(buf, 0, sizeof(buf));
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 = vdi_size;
ret = do_req(fd, (SheepdogReq *)&hdr, buf, &wlen, &rlen);
closesocket(fd);
if (ret) {
return -EIO;
}
if (rsp->result != SD_RES_SUCCESS) {
error_report("%s, %s", sd_strerror(rsp->result), filename);
return -EIO;
}
if (vdi_id) {
*vdi_id = rsp->vdi_id;
}
return 0;
}
static int sd_prealloc(const char *filename)
{
BlockDriverState *bs = NULL;
uint32_t idx, max_idx;
int64_t vdi_size;
void *buf = g_malloc0(SD_DATA_OBJ_SIZE);
int ret;
ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR);
if (ret < 0) {
goto out;
}
vdi_size = bdrv_getlength(bs);
if (vdi_size < 0) {
ret = vdi_size;
goto out;
}
max_idx = DIV_ROUND_UP(vdi_size, SD_DATA_OBJ_SIZE);
for (idx = 0; idx < max_idx; idx++) {
/*
* The created image can be a cloned image, so we need to read
* a data from the source image.
*/
ret = bdrv_pread(bs, idx * SD_DATA_OBJ_SIZE, buf, SD_DATA_OBJ_SIZE);
if (ret < 0) {
goto out;
}
ret = bdrv_pwrite(bs, idx * SD_DATA_OBJ_SIZE, buf, SD_DATA_OBJ_SIZE);
if (ret < 0) {
goto out;
}
}
out:
if (bs) {
bdrv_delete(bs);
}
g_free(buf);
return ret;
}
static int sd_create(const char *filename, QEMUOptionParameter *options)
{
int ret;
uint32_t vid = 0, base_vid = 0;
int64_t vdi_size = 0;
char *backing_file = NULL;
BDRVSheepdogState s;
char vdi[SD_MAX_VDI_LEN], tag[SD_MAX_VDI_TAG_LEN];
uint32_t snapid;
int prealloc = 0;
const char *vdiname;
strstart(filename, "sheepdog:", &vdiname);
memset(&s, 0, sizeof(s));
memset(vdi, 0, sizeof(vdi));
memset(tag, 0, sizeof(tag));
if (parse_vdiname(&s, vdiname, vdi, &snapid, tag) < 0) {
error_report("invalid filename");
return -EINVAL;
}
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
vdi_size = options->value.n;
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
backing_file = options->value.s;
} else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
if (!options->value.s || !strcmp(options->value.s, "off")) {
prealloc = 0;
} else if (!strcmp(options->value.s, "full")) {
prealloc = 1;
} else {
error_report("Invalid preallocation mode: '%s'",
options->value.s);
return -EINVAL;
}
}
options++;
}
if (vdi_size > SD_MAX_VDI_SIZE) {
error_report("too big image size");
return -EINVAL;
}
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");
return -EINVAL;
}
ret = bdrv_file_open(&bs, backing_file, 0);
if (ret < 0)
return -EIO;
s = bs->opaque;
if (!is_snapshot(&s->inode)) {
error_report("cannot clone from a non snapshot vdi");
bdrv_delete(bs);
return -EINVAL;
}
base_vid = s->inode.vdi_id;
bdrv_delete(bs);
}
ret = do_sd_create(vdi, vdi_size, base_vid, &vid, 0, s.addr, s.port);
if (!prealloc || ret) {
return ret;
}
return sd_prealloc(filename);
}
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);
closesocket(fd);
if (!ret && rsp->result != SD_RES_SUCCESS &&
rsp->result != SD_RES_VDI_NOT_LOCKED) {
error_report("%s, %s", sd_strerror(rsp->result), s->name);
}
qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL, NULL, NULL);
closesocket(s->fd);
g_free(s->addr);
}
static int64_t sd_getlength(BlockDriverState *bs)
{
BDRVSheepdogState *s = bs->opaque;
return s->inode.vdi_size;
}
static int sd_truncate(BlockDriverState *bs, int64_t offset)
{
BDRVSheepdogState *s = bs->opaque;
int ret, fd;
unsigned int datalen;
if (offset < s->inode.vdi_size) {
error_report("shrinking is not supported");
return -EINVAL;
} else if (offset > SD_MAX_VDI_SIZE) {
error_report("too big image size");
return -EINVAL;
}
fd = connect_to_sdog(s->addr, s->port);
if (fd < 0) {
return -EIO;
}
/* we don't need to update entire object */
datalen = SD_INODE_SIZE - sizeof(s->inode.data_vdi_id);
s->inode.vdi_size = offset;
ret = write_object(fd, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id),
s->inode.nr_copies, datalen, 0, 0);
close(fd);
if (ret < 0) {
error_report("failed to update an inode.");
return -EIO;
}
return 0;
}
/*
* This function is called after writing data objects. If we need to
* update metadata, this sends a write request to the vdi object.
* Otherwise, this switches back to sd_co_readv/writev.
*/
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 snapshot.\n", s->inode.vdi_id);
buf = g_malloc(SD_INODE_SIZE);
ret = do_sd_create(s->name, s->inode.vdi_size, 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");
goto out;
}
ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies,
SD_INODE_SIZE, 0);
closesocket(fd);
if (ret < 0) {
goto out;
}
memcpy(&s->inode, buf, sizeof(s->inode));
s->is_snapshot = 0;
ret = 0;
dprintf("%" PRIx32 " was newly created.\n", s->inode.vdi_id);
out:
g_free(buf);
return ret;
}
/*
* Send I/O requests to the server.
*
* This function sends requests to the server, links the requests to
* the 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.
*
* Returns 1 when we need to wait a response, 0 when there is no sent
* request and -errno in error cases.
*/
static int sd_co_rw_vector(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;
if (acb->aiocb_type == AIOCB_WRITE_UDATA && s->is_snapshot) {
/*
* In the case we open the snapshot VDI, Sheepdog creates the
* writable VDI when we do a write operation first.
*/
ret = sd_create_branch(s);
if (ret) {
acb->ret = -EIO;
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(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_writable(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");
free_aio_req(s, aio_req);
acb->ret = -EIO;
goto out;
}
done:
offset = 0;
idx++;
done += len;
}
out:
if (QLIST_EMPTY(&acb->aioreq_head)) {
return acb->ret;
}
return 1;
}
static int sd_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
SheepdogAIOCB *acb;
int ret;
if (bs->growable && sector_num + nb_sectors > bs->total_sectors) {
/* TODO: shouldn't block here */
if (sd_truncate(bs, (sector_num + nb_sectors) * SECTOR_SIZE) < 0) {
return -EIO;
}
bs->total_sectors = sector_num + nb_sectors;
}
acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors, NULL, NULL);
acb->aio_done_func = sd_write_done;
acb->aiocb_type = AIOCB_WRITE_UDATA;
ret = sd_co_rw_vector(acb);
if (ret <= 0) {
qemu_aio_release(acb);
return ret;
}
qemu_coroutine_yield();
return acb->ret;
}
static int sd_co_readv(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
SheepdogAIOCB *acb;
int i, ret;
acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors, NULL, NULL);
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);
}
ret = sd_co_rw_vector(acb);
if (ret <= 0) {
qemu_aio_release(acb);
return ret;
}
qemu_coroutine_yield();
return acb->ret;
}
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;
dprintf("sn_info: name %s id_str %s s: name %s vm_state_size %d "
"is_snapshot %d\n", sn_info->name, sn_info->id_str,
s->name, sn_info->vm_state_size, s->is_snapshot);
if (s->is_snapshot) {
error_report("You can't create a snapshot of a snapshot VDI, "
"%s (%" PRIu32 ").", s->name, s->inode.vdi_id);
return -EINVAL;
}
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;
strncpy(s->inode.tag, sn_info->name, sizeof(s->inode.tag));
/* we don't need to update 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, 0, 0);
if (ret < 0) {
error_report("failed to write snapshot's inode.");
ret = -EIO;
goto cleanup;
}
ret = do_sd_create(s->name, s->inode.vdi_size, s->inode.vdi_id, &new_vid, 1,
s->addr, s->port);
if (ret < 0) {
error_report("failed to create inode for snapshot. %s",
strerror(errno));
ret = -EIO;
goto cleanup;
}
inode = (SheepdogInode *)g_malloc(datalen);
ret = read_object(fd, (char *)inode, vid_to_vdi_oid(new_vid),
s->inode.nr_copies, datalen, 0);
if (ret < 0) {
error_report("failed to read new inode info. %s", 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:
closesocket(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], tag[SD_MAX_VDI_TAG_LEN];
char *buf = NULL;
uint32_t vid;
uint32_t snapid = 0;
int ret = -ENOENT, fd;
old_s = g_malloc(sizeof(BDRVSheepdogState));
memcpy(old_s, s, sizeof(BDRVSheepdogState));
memset(vdi, 0, sizeof(vdi));
strncpy(vdi, s->name, sizeof(vdi));
memset(tag, 0, sizeof(tag));
snapid = strtoul(snapshot_id, NULL, 10);
if (!snapid) {
strncpy(tag, s->name, sizeof(tag));
}
ret = find_vdi_name(s, vdi, snapid, tag, &vid, 1);
if (ret) {
error_report("Failed to find_vdi_name");
ret = -ENOENT;
goto out;
}
fd = connect_to_sdog(s->addr, s->port);
if (fd < 0) {
error_report("failed to connect");
goto out;
}
buf = g_malloc(SD_INODE_SIZE);
ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies,
SD_INODE_SIZE, 0);
closesocket(fd);
if (ret) {
ret = -ENOENT;
goto out;
}
memcpy(&s->inode, buf, sizeof(s->inode));
if (!s->inode.vm_state_size) {
error_report("Invalid snapshot");
ret = -ENOENT;
goto out;
}
s->is_snapshot = 1;
g_free(buf);
g_free(old_s);
return 0;
out:
/* recover bdrv_sd_state */
memcpy(s, old_s, sizeof(BDRVSheepdogState));
g_free(buf);
g_free(old_s);
error_report("failed to open. recover old bdrv_sd_state.");
return ret;
}
static int sd_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
/* FIXME: Delete specified snapshot id. */
return 0;
}
static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
{
BDRVSheepdogState *s = bs->opaque;
SheepdogReq req;
int fd, nr = 1024, ret, max = BITS_TO_LONGS(SD_NR_VDIS) * sizeof(long);
QEMUSnapshotInfo *sn_tab = NULL;
unsigned wlen, rlen;
int found = 0;
static SheepdogInode inode;
unsigned long *vdi_inuse;
unsigned int start_nr;
uint64_t hval;
uint32_t vid;
vdi_inuse = g_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);
closesocket(fd);
if (ret) {
goto out;
}
sn_tab = g_malloc0(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");
goto out;
}
for (vid = start_nr; found < nr; vid = (vid + 1) % SD_NR_VDIS) {
if (!test_bit(vid, vdi_inuse)) {
break;
}
/* we don't need to read entire object */
ret = read_object(fd, (char *)&inode, vid_to_vdi_oid(vid),
0, SD_INODE_SIZE - sizeof(inode.data_vdi_id), 0);
if (ret) {
continue;
}
if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) {
sn_tab[found].date_sec = inode.snap_ctime >> 32;
sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff;
sn_tab[found].vm_state_size = inode.vm_state_size;
sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec;
snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str), "%u",
inode.snap_id);
strncpy(sn_tab[found].name, inode.tag,
MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)));
found++;
}
}
closesocket(fd);
out:
*psn_tab = sn_tab;
g_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(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", strerror(errno));
ret = -EIO;
goto cleanup;
}
pos += data_len;
size -= data_len;
ret += data_len;
}
cleanup:
closesocket(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"
},
{
.name = BLOCK_OPT_PREALLOC,
.type = OPT_STRING,
.help = "Preallocation mode (allowed values: off, full)"
},
{ 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_getlength = sd_getlength,
.bdrv_truncate = sd_truncate,
.bdrv_co_readv = sd_co_readv,
.bdrv_co_writev = sd_co_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);
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