diff options
Diffstat (limited to 'src/block/sheepdog.c')
| -rw-r--r-- | src/block/sheepdog.c | 2910 |
1 files changed, 2910 insertions, 0 deletions
diff --git a/src/block/sheepdog.c b/src/block/sheepdog.c new file mode 100644 index 0000000..d80e4ed --- /dev/null +++ b/src/block/sheepdog.c @@ -0,0 +1,2910 @@ +/* + * 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/>. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "qemu/uri.h" +#include "qemu/error-report.h" +#include "qemu/sockets.h" +#include "block/block_int.h" +#include "qemu/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 +/* 0x04 is used internally by Sheepdog */ + +#define SD_OP_NEW_VDI 0x11 +#define SD_OP_LOCK_VDI 0x12 +#define SD_OP_RELEASE_VDI 0x13 +#define SD_OP_GET_VDI_INFO 0x14 +#define SD_OP_READ_VDIS 0x15 +#define SD_OP_FLUSH_VDI 0x16 +#define SD_OP_DEL_VDI 0x17 +#define SD_OP_GET_CLUSTER_DEFAULT 0x18 + +#define SD_FLAG_CMD_WRITE 0x01 +#define SD_FLAG_CMD_COW 0x02 +#define SD_FLAG_CMD_CACHE 0x04 /* Writeback mode for cache */ +#define SD_FLAG_CMD_DIRECT 0x08 /* Don't use cache */ + +#define SD_RES_SUCCESS 0x00 /* Success */ +#define SD_RES_UNKNOWN 0x01 /* Unknown error */ +#define SD_RES_NO_OBJ 0x02 /* No object found */ +#define SD_RES_EIO 0x03 /* I/O error */ +#define SD_RES_VDI_EXIST 0x04 /* Vdi exists already */ +#define SD_RES_INVALID_PARMS 0x05 /* Invalid parameters */ +#define SD_RES_SYSTEM_ERROR 0x06 /* System error */ +#define SD_RES_VDI_LOCKED 0x07 /* Vdi is locked */ +#define SD_RES_NO_VDI 0x08 /* No vdi found */ +#define SD_RES_NO_BASE_VDI 0x09 /* No base vdi found */ +#define SD_RES_VDI_READ 0x0A /* Cannot read requested vdi */ +#define SD_RES_VDI_WRITE 0x0B /* Cannot write requested vdi */ +#define SD_RES_BASE_VDI_READ 0x0C /* Cannot read base vdi */ +#define SD_RES_BASE_VDI_WRITE 0x0D /* Cannot write base vdi */ +#define SD_RES_NO_TAG 0x0E /* Requested tag is not found */ +#define SD_RES_STARTUP 0x0F /* Sheepdog is on starting up */ +#define SD_RES_VDI_NOT_LOCKED 0x10 /* Vdi is not locked */ +#define SD_RES_SHUTDOWN 0x11 /* Sheepdog is shutting down */ +#define SD_RES_NO_MEM 0x12 /* Cannot allocate memory */ +#define SD_RES_FULL_VDI 0x13 /* we already have the maximum vdis */ +#define SD_RES_VER_MISMATCH 0x14 /* Protocol version mismatch */ +#define SD_RES_NO_SPACE 0x15 /* Server has no room for new objects */ +#define SD_RES_WAIT_FOR_FORMAT 0x16 /* Waiting for a format operation */ +#define SD_RES_WAIT_FOR_JOIN 0x17 /* Waiting for other nodes joining */ +#define SD_RES_JOIN_FAILED 0x18 /* Target node had failed to join sheepdog */ +#define SD_RES_HALT 0x19 /* Sheepdog is stopped serving IO request */ +#define SD_RES_READONLY 0x1A /* Object is read-only */ + +/* + * Object ID rules + * + * 0 - 19 (20 bits): data object space + * 20 - 31 (12 bits): reserved data object space + * 32 - 55 (24 bits): vdi object space + * 56 - 59 ( 4 bits): reserved vdi object space + * 60 - 63 ( 4 bits): object type identifier space + */ + +#define VDI_SPACE_SHIFT 32 +#define VDI_BIT (UINT64_C(1) << 63) +#define VMSTATE_BIT (UINT64_C(1) << 62) +#define MAX_DATA_OBJS (UINT64_C(1) << 20) +#define MAX_CHILDREN 1024 +#define SD_MAX_VDI_LEN 256 +#define SD_MAX_VDI_TAG_LEN 256 +#define SD_NR_VDIS (1U << 24) +#define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22) +#define SD_MAX_VDI_SIZE (SD_DATA_OBJ_SIZE * MAX_DATA_OBJS) +#define SD_DEFAULT_BLOCK_SIZE_SHIFT 22 +/* + * For erasure coding, we use at most SD_EC_MAX_STRIP for data strips and + * (SD_EC_MAX_STRIP - 1) for parity strips + * + * SD_MAX_COPIES is sum of number of data strips and parity strips. + */ +#define SD_EC_MAX_STRIP 16 +#define SD_MAX_COPIES (SD_EC_MAX_STRIP * 2 - 1) + +#define SD_INODE_SIZE (sizeof(SheepdogInode)) +#define CURRENT_VDI_ID 0 + +#define LOCK_TYPE_NORMAL 0 +#define LOCK_TYPE_SHARED 1 /* for iSCSI multipath */ + +typedef struct SheepdogReq { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint32_t opcode_specific[8]; +} SheepdogReq; + +typedef struct SheepdogRsp { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint32_t result; + uint32_t opcode_specific[7]; +} SheepdogRsp; + +typedef struct SheepdogObjReq { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint64_t oid; + uint64_t cow_oid; + uint8_t copies; + uint8_t copy_policy; + uint8_t reserved[6]; + uint64_t offset; +} SheepdogObjReq; + +typedef struct SheepdogObjRsp { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint32_t result; + uint8_t copies; + uint8_t copy_policy; + uint8_t reserved[2]; + uint32_t pad[6]; +} SheepdogObjRsp; + +typedef struct SheepdogVdiReq { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint64_t vdi_size; + uint32_t base_vdi_id; + uint8_t copies; + uint8_t copy_policy; + uint8_t store_policy; + uint8_t block_size_shift; + uint32_t snapid; + uint32_t type; + uint32_t pad[2]; +} SheepdogVdiReq; + +typedef struct SheepdogVdiRsp { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint32_t result; + uint32_t rsvd; + uint32_t vdi_id; + uint32_t pad[5]; +} SheepdogVdiRsp; + +typedef struct SheepdogClusterRsp { + uint8_t proto_ver; + uint8_t opcode; + uint16_t flags; + uint32_t epoch; + uint32_t id; + uint32_t data_length; + uint32_t result; + uint8_t nr_copies; + uint8_t copy_policy; + uint8_t block_size_shift; + uint8_t __pad1; + uint32_t __pad2[6]; +} SheepdogClusterRsp; + +typedef struct SheepdogInode { + char name[SD_MAX_VDI_LEN]; + char tag[SD_MAX_VDI_TAG_LEN]; + uint64_t ctime; + uint64_t snap_ctime; + uint64_t vm_clock_nsec; + uint64_t vdi_size; + uint64_t vm_state_size; + uint16_t copy_policy; + uint8_t nr_copies; + uint8_t block_size_shift; + uint32_t snap_id; + uint32_t vdi_id; + uint32_t parent_vdi_id; + uint32_t child_vdi_id[MAX_CHILDREN]; + uint32_t data_vdi_id[MAX_DATA_OBJS]; +} SheepdogInode; + +#define SD_INODE_HEADER_SIZE offsetof(SheepdogInode, data_vdi_id) + +/* + * 64 bit FNV-1a non-zero initial basis + */ +#define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL) + +/* + * 64 bit Fowler/Noll/Vo FNV-1a hash code + */ +static inline uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval) +{ + unsigned char *bp = buf; + unsigned char *be = bp + len; + while (bp < be) { + hval ^= (uint64_t) *bp++; + hval += (hval << 1) + (hval << 4) + (hval << 5) + + (hval << 7) + (hval << 8) + (hval << 40); + } + return hval; +} + +static inline bool is_data_obj_writable(SheepdogInode *inode, unsigned int idx) +{ + return inode->vdi_id == inode->data_vdi_id[idx]; +} + +static inline bool is_data_obj(uint64_t oid) +{ + return !(VDI_BIT & oid); +} + +static inline uint64_t data_oid_to_idx(uint64_t oid) +{ + return oid & (MAX_DATA_OBJS - 1); +} + +static inline uint32_t oid_to_vid(uint64_t oid) +{ + return (oid & ~VDI_BIT) >> VDI_SPACE_SHIFT; +} + +static inline uint64_t vid_to_vdi_oid(uint32_t vid) +{ + return VDI_BIT | ((uint64_t)vid << VDI_SPACE_SHIFT); +} + +static inline uint64_t vid_to_vmstate_oid(uint32_t vid, uint32_t idx) +{ + return VMSTATE_BIT | ((uint64_t)vid << VDI_SPACE_SHIFT) | idx; +} + +static inline uint64_t vid_to_data_oid(uint32_t vid, uint32_t idx) +{ + return ((uint64_t)vid << VDI_SPACE_SHIFT) | idx; +} + +static inline bool is_snapshot(struct SheepdogInode *inode) +{ + return !!inode->snap_ctime; +} + +#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; + bool create; + + QLIST_ENTRY(AIOReq) aio_siblings; +} AIOReq; + +enum AIOCBState { + AIOCB_WRITE_UDATA, + AIOCB_READ_UDATA, + AIOCB_FLUSH_CACHE, + AIOCB_DISCARD_OBJ, +}; + +#define AIOCBOverlapping(x, y) \ + (!(x->max_affect_data_idx < y->min_affect_data_idx \ + || y->max_affect_data_idx < x->min_affect_data_idx)) + +struct SheepdogAIOCB { + BlockAIOCB common; + + QEMUIOVector *qiov; + + int64_t sector_num; + int nb_sectors; + + int ret; + enum AIOCBState aiocb_type; + + Coroutine *coroutine; + void (*aio_done_func)(SheepdogAIOCB *); + + bool cancelable; + int nr_pending; + + uint32_t min_affect_data_idx; + uint32_t max_affect_data_idx; + + /* + * The difference between affect_data_idx and dirty_data_idx: + * affect_data_idx represents range of index of all request types. + * dirty_data_idx represents range of index updated by COW requests. + * dirty_data_idx is used for updating an inode object. + */ + uint32_t min_dirty_data_idx; + uint32_t max_dirty_data_idx; + + QLIST_ENTRY(SheepdogAIOCB) aiocb_siblings; +}; + +typedef struct BDRVSheepdogState { + BlockDriverState *bs; + AioContext *aio_context; + + SheepdogInode inode; + + char name[SD_MAX_VDI_LEN]; + bool is_snapshot; + uint32_t cache_flags; + bool discard_supported; + + char *host_spec; + bool is_unix; + int fd; + + CoMutex lock; + Coroutine *co_send; + Coroutine *co_recv; + + uint32_t aioreq_seq_num; + + /* Every aio request must be linked to either of these queues. */ + QLIST_HEAD(inflight_aio_head, AIOReq) inflight_aio_head; + QLIST_HEAD(failed_aio_head, AIOReq) failed_aio_head; + + CoQueue overlapping_queue; + QLIST_HEAD(inflight_aiocb_head, SheepdogAIOCB) inflight_aiocb_head; +} BDRVSheepdogState; + +typedef struct BDRVSheepdogReopenState { + int fd; + int cache_flags; +} BDRVSheepdogReopenState; + +static const char * sd_strerror(int err) +{ + int i; + + static const struct { + int err; + const char *desc; + } errors[] = { + {SD_RES_SUCCESS, "Success"}, + {SD_RES_UNKNOWN, "Unknown error"}, + {SD_RES_NO_OBJ, "No object found"}, + {SD_RES_EIO, "I/O error"}, + {SD_RES_VDI_EXIST, "VDI exists already"}, + {SD_RES_INVALID_PARMS, "Invalid parameters"}, + {SD_RES_SYSTEM_ERROR, "System error"}, + {SD_RES_VDI_LOCKED, "VDI is already locked"}, + {SD_RES_NO_VDI, "No vdi found"}, + {SD_RES_NO_BASE_VDI, "No base VDI found"}, + {SD_RES_VDI_READ, "Failed read the requested VDI"}, + {SD_RES_VDI_WRITE, "Failed to write the requested VDI"}, + {SD_RES_BASE_VDI_READ, "Failed to read the base VDI"}, + {SD_RES_BASE_VDI_WRITE, "Failed to write the base VDI"}, + {SD_RES_NO_TAG, "Failed to find the requested tag"}, + {SD_RES_STARTUP, "The system is still booting"}, + {SD_RES_VDI_NOT_LOCKED, "VDI isn't locked"}, + {SD_RES_SHUTDOWN, "The system is shutting down"}, + {SD_RES_NO_MEM, "Out of memory on the server"}, + {SD_RES_FULL_VDI, "We already have the maximum vdis"}, + {SD_RES_VER_MISMATCH, "Protocol version mismatch"}, + {SD_RES_NO_SPACE, "Server has no space for new objects"}, + {SD_RES_WAIT_FOR_FORMAT, "Sheepdog is waiting for a format operation"}, + {SD_RES_WAIT_FOR_JOIN, "Sheepdog is waiting for other nodes joining"}, + {SD_RES_JOIN_FAILED, "Target node had failed to join sheepdog"}, + {SD_RES_HALT, "Sheepdog is stopped serving IO request"}, + {SD_RES_READONLY, "Object is read-only"}, + }; + + for (i = 0; i < ARRAY_SIZE(errors); ++i) { + if (errors[i].err == err) { + return errors[i].desc; + } + } + + return "Invalid error code"; +} + +/* + * Sheepdog I/O handling: + * + * 1. In sd_co_rw_vector, we send the I/O requests to the server and + * link the requests to the inflight_list in the + * BDRVSheepdogState. The function 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, bool create, + uint64_t base_oid, unsigned int iov_offset) +{ + AIOReq *aio_req; + + aio_req = g_malloc(sizeof(*aio_req)); + aio_req->aiocb = acb; + aio_req->iov_offset = iov_offset; + aio_req->oid = oid; + aio_req->base_oid = base_oid; + aio_req->offset = offset; + aio_req->data_len = data_len; + aio_req->flags = flags; + aio_req->id = s->aioreq_seq_num++; + aio_req->create = create; + + acb->nr_pending++; + return aio_req; +} + +static inline void free_aio_req(BDRVSheepdogState *s, AIOReq *aio_req) +{ + SheepdogAIOCB *acb = aio_req->aiocb; + + acb->cancelable = false; + QLIST_REMOVE(aio_req, aio_siblings); + g_free(aio_req); + + acb->nr_pending--; +} + +static void coroutine_fn sd_finish_aiocb(SheepdogAIOCB *acb) +{ + qemu_coroutine_enter(acb->coroutine, NULL); + qemu_aio_unref(acb); +} + +/* + * Check whether the specified acb can be canceled + * + * We can cancel aio when any request belonging to the acb is: + * - Not processed by the sheepdog server. + * - Not linked to the inflight queue. + */ +static bool sd_acb_cancelable(const SheepdogAIOCB *acb) +{ + BDRVSheepdogState *s = acb->common.bs->opaque; + AIOReq *aioreq; + + if (!acb->cancelable) { + return false; + } + + QLIST_FOREACH(aioreq, &s->inflight_aio_head, aio_siblings) { + if (aioreq->aiocb == acb) { + return false; + } + } + + return true; +} + +static void sd_aio_cancel(BlockAIOCB *blockacb) +{ + SheepdogAIOCB *acb = (SheepdogAIOCB *)blockacb; + BDRVSheepdogState *s = acb->common.bs->opaque; + AIOReq *aioreq, *next; + + if (sd_acb_cancelable(acb)) { + /* Remove outstanding requests from failed queue. */ + QLIST_FOREACH_SAFE(aioreq, &s->failed_aio_head, aio_siblings, + next) { + if (aioreq->aiocb == acb) { + free_aio_req(s, aioreq); + } + } + + assert(acb->nr_pending == 0); + if (acb->common.cb) { + acb->common.cb(acb->common.opaque, -ECANCELED); + } + sd_finish_aiocb(acb); + } +} + +static const AIOCBInfo sd_aiocb_info = { + .aiocb_size = sizeof(SheepdogAIOCB), + .cancel_async = sd_aio_cancel, +}; + +static SheepdogAIOCB *sd_aio_setup(BlockDriverState *bs, QEMUIOVector *qiov, + int64_t sector_num, int nb_sectors) +{ + SheepdogAIOCB *acb; + uint32_t object_size; + BDRVSheepdogState *s = bs->opaque; + + object_size = (UINT32_C(1) << s->inode.block_size_shift); + + acb = qemu_aio_get(&sd_aiocb_info, bs, NULL, NULL); + + acb->qiov = qiov; + + acb->sector_num = sector_num; + acb->nb_sectors = nb_sectors; + + acb->aio_done_func = NULL; + acb->cancelable = true; + acb->coroutine = qemu_coroutine_self(); + acb->ret = 0; + acb->nr_pending = 0; + + acb->min_affect_data_idx = acb->sector_num * BDRV_SECTOR_SIZE / object_size; + acb->max_affect_data_idx = (acb->sector_num * BDRV_SECTOR_SIZE + + acb->nb_sectors * BDRV_SECTOR_SIZE) / object_size; + + acb->min_dirty_data_idx = UINT32_MAX; + acb->max_dirty_data_idx = 0; + + return acb; +} + +/* Return -EIO in case of error, file descriptor on success */ +static int connect_to_sdog(BDRVSheepdogState *s, Error **errp) +{ + int fd; + + if (s->is_unix) { + fd = unix_connect(s->host_spec, errp); + } else { + fd = inet_connect(s->host_spec, errp); + + if (fd >= 0) { + int ret = socket_set_nodelay(fd); + if (ret < 0) { + error_report("%s", strerror(errno)); + } + } + } + + if (fd >= 0) { + qemu_set_nonblock(fd); + } else { + fd = -EIO; + } + + return fd; +} + +/* Return 0 on success and -errno in case of error */ +static coroutine_fn int send_co_req(int sockfd, SheepdogReq *hdr, void *data, + unsigned int *wlen) +{ + int ret; + + ret = qemu_co_send(sockfd, hdr, sizeof(*hdr)); + if (ret != sizeof(*hdr)) { + error_report("failed to send a req, %s", strerror(errno)); + ret = -socket_error(); + return ret; + } + + ret = qemu_co_send(sockfd, data, *wlen); + if (ret != *wlen) { + ret = -socket_error(); + error_report("failed to send a req, %s", strerror(errno)); + } + + return ret; +} + +static void restart_co_req(void *opaque) +{ + Coroutine *co = opaque; + + qemu_coroutine_enter(co, NULL); +} + +typedef struct SheepdogReqCo { + int sockfd; + AioContext *aio_context; + SheepdogReq *hdr; + void *data; + unsigned int *wlen; + unsigned int *rlen; + int ret; + bool finished; +} SheepdogReqCo; + +static coroutine_fn void do_co_req(void *opaque) +{ + int ret; + Coroutine *co; + SheepdogReqCo *srco = opaque; + int sockfd = srco->sockfd; + SheepdogReq *hdr = srco->hdr; + void *data = srco->data; + unsigned int *wlen = srco->wlen; + unsigned int *rlen = srco->rlen; + + co = qemu_coroutine_self(); + aio_set_fd_handler(srco->aio_context, sockfd, false, + NULL, restart_co_req, co); + + ret = send_co_req(sockfd, hdr, data, wlen); + if (ret < 0) { + goto out; + } + + aio_set_fd_handler(srco->aio_context, sockfd, false, + restart_co_req, NULL, co); + + ret = qemu_co_recv(sockfd, hdr, sizeof(*hdr)); + if (ret != sizeof(*hdr)) { + error_report("failed to get a rsp, %s", strerror(errno)); + ret = -errno; + goto out; + } + + if (*rlen > hdr->data_length) { + *rlen = hdr->data_length; + } + + if (*rlen) { + ret = qemu_co_recv(sockfd, data, *rlen); + if (ret != *rlen) { + error_report("failed to get the data, %s", strerror(errno)); + ret = -errno; + goto out; + } + } + ret = 0; +out: + /* there is at most one request for this sockfd, so it is safe to + * set each handler to NULL. */ + aio_set_fd_handler(srco->aio_context, sockfd, false, + NULL, NULL, NULL); + + srco->ret = ret; + srco->finished = true; +} + +/* + * Send the request to the sheep in a synchronous manner. + * + * Return 0 on success, -errno in case of error. + */ +static int do_req(int sockfd, AioContext *aio_context, SheepdogReq *hdr, + void *data, unsigned int *wlen, unsigned int *rlen) +{ + Coroutine *co; + SheepdogReqCo srco = { + .sockfd = sockfd, + .aio_context = aio_context, + .hdr = hdr, + .data = data, + .wlen = wlen, + .rlen = rlen, + .ret = 0, + .finished = false, + }; + + if (qemu_in_coroutine()) { + do_co_req(&srco); + } else { + co = qemu_coroutine_create(do_co_req); + qemu_coroutine_enter(co, &srco); + while (!srco.finished) { + aio_poll(aio_context, true); + } + } + + return srco.ret; +} + +static void coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, + struct iovec *iov, int niov, + enum AIOCBState aiocb_type); +static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req); +static int reload_inode(BDRVSheepdogState *s, uint32_t snapid, const char *tag); +static int get_sheep_fd(BDRVSheepdogState *s, Error **errp); +static void co_write_request(void *opaque); + +static coroutine_fn void reconnect_to_sdog(void *opaque) +{ + BDRVSheepdogState *s = opaque; + AIOReq *aio_req, *next; + + aio_set_fd_handler(s->aio_context, s->fd, false, NULL, + NULL, NULL); + close(s->fd); + s->fd = -1; + + /* Wait for outstanding write requests to be completed. */ + while (s->co_send != NULL) { + co_write_request(opaque); + } + + /* Try to reconnect the sheepdog server every one second. */ + while (s->fd < 0) { + Error *local_err = NULL; + s->fd = get_sheep_fd(s, &local_err); + if (s->fd < 0) { + DPRINTF("Wait for connection to be established\n"); + error_report_err(local_err); + co_aio_sleep_ns(bdrv_get_aio_context(s->bs), QEMU_CLOCK_REALTIME, + 1000000000ULL); + } + }; + + /* + * Now we have to resend all the request in the inflight queue. However, + * resend_aioreq() can yield and newly created requests can be added to the + * inflight queue before the coroutine is resumed. To avoid mixing them, we + * have to move all the inflight requests to the failed queue before + * resend_aioreq() is called. + */ + QLIST_FOREACH_SAFE(aio_req, &s->inflight_aio_head, aio_siblings, next) { + QLIST_REMOVE(aio_req, aio_siblings); + QLIST_INSERT_HEAD(&s->failed_aio_head, aio_req, aio_siblings); + } + + /* Resend all the failed aio requests. */ + while (!QLIST_EMPTY(&s->failed_aio_head)) { + aio_req = QLIST_FIRST(&s->failed_aio_head); + QLIST_REMOVE(aio_req, aio_siblings); + QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings); + resend_aioreq(s, aio_req); + } +} + +/* + * Receive responses of the I/O requests. + * + * This function is registered as a fd handler, and called from the + * main loop when s->fd is ready for reading responses. + */ +static void coroutine_fn aio_read_response(void *opaque) +{ + SheepdogObjRsp rsp; + BDRVSheepdogState *s = opaque; + int fd = s->fd; + int ret; + AIOReq *aio_req = NULL; + SheepdogAIOCB *acb; + uint64_t idx; + + /* read a header */ + ret = qemu_co_recv(fd, &rsp, sizeof(rsp)); + if (ret != sizeof(rsp)) { + error_report("failed to get the header, %s", strerror(errno)); + goto err; + } + + /* find the right aio_req from the inflight aio list */ + QLIST_FOREACH(aio_req, &s->inflight_aio_head, aio_siblings) { + if (aio_req->id == rsp.id) { + break; + } + } + if (!aio_req) { + error_report("cannot find aio_req %x", rsp.id); + goto err; + } + + acb = aio_req->aiocb; + + switch (acb->aiocb_type) { + case AIOCB_WRITE_UDATA: + /* this coroutine context is no longer suitable for co_recv + * because we may send data to update vdi objects */ + s->co_recv = NULL; + if (!is_data_obj(aio_req->oid)) { + break; + } + idx = data_oid_to_idx(aio_req->oid); + + if (aio_req->create) { + /* + * If the object is newly created one, we need to update + * the vdi object (metadata object). min_dirty_data_idx + * and max_dirty_data_idx are changed to include updated + * index between them. + */ + if (rsp.result == SD_RES_SUCCESS) { + s->inode.data_vdi_id[idx] = s->inode.vdi_id; + acb->max_dirty_data_idx = MAX(idx, acb->max_dirty_data_idx); + acb->min_dirty_data_idx = MIN(idx, acb->min_dirty_data_idx); + } + } + break; + case AIOCB_READ_UDATA: + ret = qemu_co_recvv(fd, acb->qiov->iov, acb->qiov->niov, + aio_req->iov_offset, rsp.data_length); + if (ret != rsp.data_length) { + error_report("failed to get the data, %s", strerror(errno)); + goto err; + } + break; + case AIOCB_FLUSH_CACHE: + if (rsp.result == SD_RES_INVALID_PARMS) { + DPRINTF("disable cache since the server doesn't support it\n"); + s->cache_flags = SD_FLAG_CMD_DIRECT; + rsp.result = SD_RES_SUCCESS; + } + break; + case AIOCB_DISCARD_OBJ: + switch (rsp.result) { + case SD_RES_INVALID_PARMS: + error_report("sheep(%s) doesn't support discard command", + s->host_spec); + rsp.result = SD_RES_SUCCESS; + s->discard_supported = false; + break; + default: + break; + } + } + + switch (rsp.result) { + case SD_RES_SUCCESS: + break; + case SD_RES_READONLY: + if (s->inode.vdi_id == oid_to_vid(aio_req->oid)) { + ret = reload_inode(s, 0, ""); + if (ret < 0) { + goto err; + } + } + if (is_data_obj(aio_req->oid)) { + aio_req->oid = vid_to_data_oid(s->inode.vdi_id, + data_oid_to_idx(aio_req->oid)); + } else { + aio_req->oid = vid_to_vdi_oid(s->inode.vdi_id); + } + resend_aioreq(s, aio_req); + goto out; + default: + acb->ret = -EIO; + error_report("%s", sd_strerror(rsp.result)); + break; + } + + free_aio_req(s, aio_req); + if (!acb->nr_pending) { + /* + * We've finished all requests which belong to the AIOCB, so + * we can switch back to sd_co_readv/writev now. + */ + acb->aio_done_func(acb); + } +out: + s->co_recv = NULL; + return; +err: + s->co_recv = NULL; + reconnect_to_sdog(opaque); +} + +static void co_read_response(void *opaque) +{ + BDRVSheepdogState *s = opaque; + + if (!s->co_recv) { + s->co_recv = qemu_coroutine_create(aio_read_response); + } + + qemu_coroutine_enter(s->co_recv, opaque); +} + +static void co_write_request(void *opaque) +{ + BDRVSheepdogState *s = opaque; + + qemu_coroutine_enter(s->co_send, NULL); +} + +/* + * Return a socket descriptor to read/write objects. + * + * We cannot use this descriptor for other operations because + * the block driver may be on waiting response from the server. + */ +static int get_sheep_fd(BDRVSheepdogState *s, Error **errp) +{ + int fd; + + fd = connect_to_sdog(s, errp); + if (fd < 0) { + return fd; + } + + aio_set_fd_handler(s->aio_context, fd, false, + co_read_response, NULL, s); + return fd; +} + +static int sd_parse_uri(BDRVSheepdogState *s, const char *filename, + char *vdi, uint32_t *snapid, char *tag) +{ + URI *uri; + QueryParams *qp = NULL; + int ret = 0; + + uri = uri_parse(filename); + if (!uri) { + return -EINVAL; + } + + /* transport */ + if (!strcmp(uri->scheme, "sheepdog")) { + s->is_unix = false; + } else if (!strcmp(uri->scheme, "sheepdog+tcp")) { + s->is_unix = false; + } else if (!strcmp(uri->scheme, "sheepdog+unix")) { + s->is_unix = true; + } else { + ret = -EINVAL; + goto out; + } + + if (uri->path == NULL || !strcmp(uri->path, "/")) { + ret = -EINVAL; + goto out; + } + pstrcpy(vdi, SD_MAX_VDI_LEN, uri->path + 1); + + qp = query_params_parse(uri->query); + if (qp->n > 1 || (s->is_unix && !qp->n) || (!s->is_unix && qp->n)) { + ret = -EINVAL; + goto out; + } + + if (s->is_unix) { + /* sheepdog+unix:///vdiname?socket=path */ + if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { + ret = -EINVAL; + goto out; + } + s->host_spec = g_strdup(qp->p[0].value); + } else { + /* sheepdog[+tcp]://[host:port]/vdiname */ + s->host_spec = g_strdup_printf("%s:%d", uri->server ?: SD_DEFAULT_ADDR, + uri->port ?: SD_DEFAULT_PORT); + } + + /* snapshot tag */ + if (uri->fragment) { + *snapid = strtoul(uri->fragment, NULL, 10); + if (*snapid == 0) { + pstrcpy(tag, SD_MAX_VDI_TAG_LEN, uri->fragment); + } + } else { + *snapid = CURRENT_VDI_ID; /* search current vdi */ + } + +out: + if (qp) { + query_params_free(qp); + } + uri_free(uri); + return ret; +} + +/* + * Parse a filename (old syntax) + * + * filename must be one of the following formats: + * 1. [vdiname] + * 2. [vdiname]:[snapid] + * 3. [vdiname]:[tag] + * 4. [hostname]:[port]:[vdiname] + * 5. [hostname]:[port]:[vdiname]:[snapid] + * 6. [hostname]:[port]:[vdiname]:[tag] + * + * You can boot from the snapshot images by specifying `snapid` or + * `tag'. + * + * You can run VMs outside the Sheepdog cluster by specifying + * `hostname' and `port' (experimental). + */ +static int parse_vdiname(BDRVSheepdogState *s, const char *filename, + char *vdi, uint32_t *snapid, char *tag) +{ + char *p, *q, *uri; + const char *host_spec, *vdi_spec; + int nr_sep, ret; + + strstart(filename, "sheepdog:", (const char **)&filename); + p = q = g_strdup(filename); + + /* count the number of separators */ + nr_sep = 0; + while (*p) { + if (*p == ':') { + nr_sep++; + } + p++; + } + p = q; + + /* use the first two tokens as host_spec. */ + if (nr_sep >= 2) { + host_spec = p; + p = strchr(p, ':'); + p++; + p = strchr(p, ':'); + *p++ = '\0'; + } else { + host_spec = ""; + } + + vdi_spec = p; + + p = strchr(vdi_spec, ':'); + if (p) { + *p++ = '#'; + } + + uri = g_strdup_printf("sheepdog://%s/%s", host_spec, vdi_spec); + + ret = sd_parse_uri(s, uri, vdi, snapid, tag); + + g_free(q); + g_free(uri); + + return ret; +} + +static int find_vdi_name(BDRVSheepdogState *s, const char *filename, + uint32_t snapid, const char *tag, uint32_t *vid, + bool lock, Error **errp) +{ + int ret, fd; + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + unsigned int wlen, rlen = 0; + char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN]; + + fd = connect_to_sdog(s, errp); + if (fd < 0) { + return fd; + } + + /* This pair of strncpy calls ensures that the buffer is zero-filled, + * which is desirable since we'll soon be sending those bytes, and + * don't want the send_req to read uninitialized data. + */ + strncpy(buf, filename, SD_MAX_VDI_LEN); + strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN); + + memset(&hdr, 0, sizeof(hdr)); + if (lock) { + hdr.opcode = SD_OP_LOCK_VDI; + hdr.type = LOCK_TYPE_NORMAL; + } else { + hdr.opcode = SD_OP_GET_VDI_INFO; + } + wlen = SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN; + hdr.proto_ver = SD_PROTO_VER; + hdr.data_length = wlen; + hdr.snapid = snapid; + hdr.flags = SD_FLAG_CMD_WRITE; + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + if (ret) { + error_setg_errno(errp, -ret, "cannot get vdi info"); + goto out; + } + + if (rsp->result != SD_RES_SUCCESS) { + error_setg(errp, "cannot get vdi info, %s, %s %" PRIu32 " %s", + sd_strerror(rsp->result), filename, snapid, tag); + if (rsp->result == SD_RES_NO_VDI) { + ret = -ENOENT; + } else if (rsp->result == SD_RES_VDI_LOCKED) { + ret = -EBUSY; + } else { + ret = -EIO; + } + goto out; + } + *vid = rsp->vdi_id; + + ret = 0; +out: + closesocket(fd); + return ret; +} + +static void coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req, + struct iovec *iov, int niov, + enum AIOCBState aiocb_type) +{ + int nr_copies = s->inode.nr_copies; + SheepdogObjReq hdr; + unsigned int wlen = 0; + int ret; + uint64_t oid = aio_req->oid; + unsigned int datalen = aio_req->data_len; + uint64_t offset = aio_req->offset; + uint8_t flags = aio_req->flags; + uint64_t old_oid = aio_req->base_oid; + bool create = aio_req->create; + + if (!nr_copies) { + error_report("bug"); + } + + memset(&hdr, 0, sizeof(hdr)); + + switch (aiocb_type) { + case AIOCB_FLUSH_CACHE: + hdr.opcode = SD_OP_FLUSH_VDI; + break; + case AIOCB_READ_UDATA: + hdr.opcode = SD_OP_READ_OBJ; + hdr.flags = flags; + break; + case AIOCB_WRITE_UDATA: + if (create) { + hdr.opcode = SD_OP_CREATE_AND_WRITE_OBJ; + } else { + hdr.opcode = SD_OP_WRITE_OBJ; + } + wlen = datalen; + hdr.flags = SD_FLAG_CMD_WRITE | flags; + break; + case AIOCB_DISCARD_OBJ: + hdr.opcode = SD_OP_WRITE_OBJ; + hdr.flags = SD_FLAG_CMD_WRITE | flags; + s->inode.data_vdi_id[data_oid_to_idx(oid)] = 0; + offset = offsetof(SheepdogInode, + data_vdi_id[data_oid_to_idx(oid)]); + oid = vid_to_vdi_oid(s->inode.vdi_id); + wlen = datalen = sizeof(uint32_t); + break; + } + + if (s->cache_flags) { + hdr.flags |= s->cache_flags; + } + + hdr.oid = oid; + hdr.cow_oid = old_oid; + hdr.copies = s->inode.nr_copies; + + hdr.data_length = datalen; + hdr.offset = offset; + + hdr.id = aio_req->id; + + qemu_co_mutex_lock(&s->lock); + s->co_send = qemu_coroutine_self(); + aio_set_fd_handler(s->aio_context, s->fd, false, + co_read_response, co_write_request, s); + socket_set_cork(s->fd, 1); + + /* send a header */ + ret = qemu_co_send(s->fd, &hdr, sizeof(hdr)); + if (ret != sizeof(hdr)) { + error_report("failed to send a req, %s", strerror(errno)); + goto out; + } + + if (wlen) { + ret = qemu_co_sendv(s->fd, iov, niov, aio_req->iov_offset, wlen); + if (ret != wlen) { + error_report("failed to send a data, %s", strerror(errno)); + } + } +out: + socket_set_cork(s->fd, 0); + aio_set_fd_handler(s->aio_context, s->fd, false, + co_read_response, NULL, s); + s->co_send = NULL; + qemu_co_mutex_unlock(&s->lock); +} + +static int read_write_object(int fd, AioContext *aio_context, char *buf, + uint64_t oid, uint8_t copies, + unsigned int datalen, uint64_t offset, + bool write, bool create, uint32_t cache_flags) +{ + SheepdogObjReq hdr; + SheepdogObjRsp *rsp = (SheepdogObjRsp *)&hdr; + unsigned int wlen, rlen; + int ret; + + memset(&hdr, 0, sizeof(hdr)); + + if (write) { + wlen = datalen; + rlen = 0; + hdr.flags = SD_FLAG_CMD_WRITE; + if (create) { + hdr.opcode = SD_OP_CREATE_AND_WRITE_OBJ; + } else { + hdr.opcode = SD_OP_WRITE_OBJ; + } + } else { + wlen = 0; + rlen = datalen; + hdr.opcode = SD_OP_READ_OBJ; + } + + hdr.flags |= cache_flags; + + hdr.oid = oid; + hdr.data_length = datalen; + hdr.offset = offset; + hdr.copies = copies; + + ret = do_req(fd, aio_context, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + if (ret) { + error_report("failed to send a request to the sheep"); + return ret; + } + + switch (rsp->result) { + case SD_RES_SUCCESS: + return 0; + default: + error_report("%s", sd_strerror(rsp->result)); + return -EIO; + } +} + +static int read_object(int fd, AioContext *aio_context, char *buf, + uint64_t oid, uint8_t copies, + unsigned int datalen, uint64_t offset, + uint32_t cache_flags) +{ + return read_write_object(fd, aio_context, buf, oid, copies, + datalen, offset, false, + false, cache_flags); +} + +static int write_object(int fd, AioContext *aio_context, char *buf, + uint64_t oid, uint8_t copies, + unsigned int datalen, uint64_t offset, bool create, + uint32_t cache_flags) +{ + return read_write_object(fd, aio_context, buf, oid, copies, + datalen, offset, true, + create, cache_flags); +} + +/* update inode with the latest state */ +static int reload_inode(BDRVSheepdogState *s, uint32_t snapid, const char *tag) +{ + Error *local_err = NULL; + SheepdogInode *inode; + int ret = 0, fd; + uint32_t vid = 0; + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + return -EIO; + } + + inode = g_malloc(SD_INODE_HEADER_SIZE); + + ret = find_vdi_name(s, s->name, snapid, tag, &vid, false, &local_err); + if (ret) { + error_report_err(local_err); + goto out; + } + + ret = read_object(fd, s->aio_context, (char *)inode, vid_to_vdi_oid(vid), + s->inode.nr_copies, SD_INODE_HEADER_SIZE, 0, + s->cache_flags); + if (ret < 0) { + goto out; + } + + if (inode->vdi_id != s->inode.vdi_id) { + memcpy(&s->inode, inode, SD_INODE_HEADER_SIZE); + } + +out: + g_free(inode); + closesocket(fd); + + return ret; +} + +static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req) +{ + SheepdogAIOCB *acb = aio_req->aiocb; + + aio_req->create = false; + + /* check whether this request becomes a CoW one */ + if (acb->aiocb_type == AIOCB_WRITE_UDATA && is_data_obj(aio_req->oid)) { + int idx = data_oid_to_idx(aio_req->oid); + + if (is_data_obj_writable(&s->inode, idx)) { + goto out; + } + + if (s->inode.data_vdi_id[idx]) { + aio_req->base_oid = vid_to_data_oid(s->inode.data_vdi_id[idx], idx); + aio_req->flags |= SD_FLAG_CMD_COW; + } + aio_req->create = true; + } +out: + if (is_data_obj(aio_req->oid)) { + add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, + acb->aiocb_type); + } else { + struct iovec iov; + iov.iov_base = &s->inode; + iov.iov_len = sizeof(s->inode); + add_aio_request(s, aio_req, &iov, 1, AIOCB_WRITE_UDATA); + } +} + +static void sd_detach_aio_context(BlockDriverState *bs) +{ + BDRVSheepdogState *s = bs->opaque; + + aio_set_fd_handler(s->aio_context, s->fd, false, NULL, + NULL, NULL); +} + +static void sd_attach_aio_context(BlockDriverState *bs, + AioContext *new_context) +{ + BDRVSheepdogState *s = bs->opaque; + + s->aio_context = new_context; + aio_set_fd_handler(new_context, s->fd, false, + co_read_response, NULL, s); +} + +/* TODO Convert to fine grained options */ +static QemuOptsList runtime_opts = { + .name = "sheepdog", + .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), + .desc = { + { + .name = "filename", + .type = QEMU_OPT_STRING, + .help = "URL to the sheepdog image", + }, + { /* end of list */ } + }, +}; + +static int sd_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + int ret, fd; + uint32_t vid = 0; + BDRVSheepdogState *s = bs->opaque; + char vdi[SD_MAX_VDI_LEN], tag[SD_MAX_VDI_TAG_LEN]; + uint32_t snapid; + char *buf = NULL; + QemuOpts *opts; + Error *local_err = NULL; + const char *filename; + + s->bs = bs; + s->aio_context = bdrv_get_aio_context(bs); + + opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto out; + } + + filename = qemu_opt_get(opts, "filename"); + + QLIST_INIT(&s->inflight_aio_head); + QLIST_INIT(&s->failed_aio_head); + QLIST_INIT(&s->inflight_aiocb_head); + s->fd = -1; + + memset(vdi, 0, sizeof(vdi)); + memset(tag, 0, sizeof(tag)); + + if (strstr(filename, "://")) { + ret = sd_parse_uri(s, filename, vdi, &snapid, tag); + } else { + ret = parse_vdiname(s, filename, vdi, &snapid, tag); + } + if (ret < 0) { + error_setg(errp, "Can't parse filename"); + goto out; + } + s->fd = get_sheep_fd(s, errp); + if (s->fd < 0) { + ret = s->fd; + goto out; + } + + ret = find_vdi_name(s, vdi, snapid, tag, &vid, true, errp); + if (ret) { + goto out; + } + + /* + * QEMU block layer emulates writethrough cache as 'writeback + flush', so + * we always set SD_FLAG_CMD_CACHE (writeback cache) as default. + */ + s->cache_flags = SD_FLAG_CMD_CACHE; + if (flags & BDRV_O_NOCACHE) { + s->cache_flags = SD_FLAG_CMD_DIRECT; + } + s->discard_supported = true; + + if (snapid || tag[0] != '\0') { + DPRINTF("%" PRIx32 " snapshot inode was open.\n", vid); + s->is_snapshot = true; + } + + fd = connect_to_sdog(s, errp); + if (fd < 0) { + ret = fd; + goto out; + } + + buf = g_malloc(SD_INODE_SIZE); + ret = read_object(fd, s->aio_context, buf, vid_to_vdi_oid(vid), + 0, SD_INODE_SIZE, 0, s->cache_flags); + + closesocket(fd); + + if (ret) { + error_setg(errp, "Can't read snapshot inode"); + goto out; + } + + memcpy(&s->inode, buf, sizeof(s->inode)); + + bs->total_sectors = s->inode.vdi_size / BDRV_SECTOR_SIZE; + pstrcpy(s->name, sizeof(s->name), vdi); + qemu_co_mutex_init(&s->lock); + qemu_co_queue_init(&s->overlapping_queue); + qemu_opts_del(opts); + g_free(buf); + return 0; +out: + aio_set_fd_handler(bdrv_get_aio_context(bs), s->fd, + false, NULL, NULL, NULL); + if (s->fd >= 0) { + closesocket(s->fd); + } + qemu_opts_del(opts); + g_free(buf); + return ret; +} + +static int sd_reopen_prepare(BDRVReopenState *state, BlockReopenQueue *queue, + Error **errp) +{ + BDRVSheepdogState *s = state->bs->opaque; + BDRVSheepdogReopenState *re_s; + int ret = 0; + + re_s = state->opaque = g_new0(BDRVSheepdogReopenState, 1); + + re_s->cache_flags = SD_FLAG_CMD_CACHE; + if (state->flags & BDRV_O_NOCACHE) { + re_s->cache_flags = SD_FLAG_CMD_DIRECT; + } + + re_s->fd = get_sheep_fd(s, errp); + if (re_s->fd < 0) { + ret = re_s->fd; + return ret; + } + + return ret; +} + +static void sd_reopen_commit(BDRVReopenState *state) +{ + BDRVSheepdogReopenState *re_s = state->opaque; + BDRVSheepdogState *s = state->bs->opaque; + + if (s->fd) { + aio_set_fd_handler(s->aio_context, s->fd, false, + NULL, NULL, NULL); + closesocket(s->fd); + } + + s->fd = re_s->fd; + s->cache_flags = re_s->cache_flags; + + g_free(state->opaque); + state->opaque = NULL; + + return; +} + +static void sd_reopen_abort(BDRVReopenState *state) +{ + BDRVSheepdogReopenState *re_s = state->opaque; + BDRVSheepdogState *s = state->bs->opaque; + + if (re_s == NULL) { + return; + } + + if (re_s->fd) { + aio_set_fd_handler(s->aio_context, re_s->fd, false, + NULL, NULL, NULL); + closesocket(re_s->fd); + } + + g_free(state->opaque); + state->opaque = NULL; + + return; +} + +static int do_sd_create(BDRVSheepdogState *s, uint32_t *vdi_id, int snapshot, + Error **errp) +{ + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + int fd, ret; + unsigned int wlen, rlen = 0; + char buf[SD_MAX_VDI_LEN]; + + fd = connect_to_sdog(s, errp); + if (fd < 0) { + return fd; + } + + /* FIXME: would it be better to fail (e.g., return -EIO) when filename + * does not fit in buf? For now, just truncate and avoid buffer overrun. + */ + memset(buf, 0, sizeof(buf)); + pstrcpy(buf, sizeof(buf), s->name); + + memset(&hdr, 0, sizeof(hdr)); + hdr.opcode = SD_OP_NEW_VDI; + hdr.base_vdi_id = s->inode.vdi_id; + + wlen = SD_MAX_VDI_LEN; + + hdr.flags = SD_FLAG_CMD_WRITE; + hdr.snapid = snapshot; + + hdr.data_length = wlen; + hdr.vdi_size = s->inode.vdi_size; + hdr.copy_policy = s->inode.copy_policy; + hdr.copies = s->inode.nr_copies; + hdr.block_size_shift = s->inode.block_size_shift; + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr, buf, &wlen, &rlen); + + closesocket(fd); + + if (ret) { + error_setg_errno(errp, -ret, "create failed"); + return ret; + } + + if (rsp->result != SD_RES_SUCCESS) { + error_setg(errp, "%s, %s", sd_strerror(rsp->result), s->inode.name); + return -EIO; + } + + if (vdi_id) { + *vdi_id = rsp->vdi_id; + } + + return 0; +} + +static int sd_prealloc(const char *filename, Error **errp) +{ + BlockDriverState *bs = NULL; + BDRVSheepdogState *base = NULL; + unsigned long buf_size; + uint32_t idx, max_idx; + uint32_t object_size; + int64_t vdi_size; + void *buf = NULL; + int ret; + + ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, + errp); + if (ret < 0) { + goto out_with_err_set; + } + + vdi_size = bdrv_getlength(bs); + if (vdi_size < 0) { + ret = vdi_size; + goto out; + } + + base = bs->opaque; + object_size = (UINT32_C(1) << base->inode.block_size_shift); + buf_size = MIN(object_size, SD_DATA_OBJ_SIZE); + buf = g_malloc0(buf_size); + + max_idx = DIV_ROUND_UP(vdi_size, buf_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 * buf_size, buf, buf_size); + if (ret < 0) { + goto out; + } + ret = bdrv_pwrite(bs, idx * buf_size, buf, buf_size); + if (ret < 0) { + goto out; + } + } + +out: + if (ret < 0) { + error_setg_errno(errp, -ret, "Can't pre-allocate"); + } +out_with_err_set: + if (bs) { + bdrv_unref(bs); + } + g_free(buf); + + return ret; +} + +/* + * Sheepdog support two kinds of redundancy, full replication and erasure + * coding. + * + * # create a fully replicated vdi with x copies + * -o redundancy=x (1 <= x <= SD_MAX_COPIES) + * + * # create a erasure coded vdi with x data strips and y parity strips + * -o redundancy=x:y (x must be one of {2,4,8,16} and 1 <= y < SD_EC_MAX_STRIP) + */ +static int parse_redundancy(BDRVSheepdogState *s, const char *opt) +{ + struct SheepdogInode *inode = &s->inode; + const char *n1, *n2; + long copy, parity; + char p[10]; + + pstrcpy(p, sizeof(p), opt); + n1 = strtok(p, ":"); + n2 = strtok(NULL, ":"); + + if (!n1) { + return -EINVAL; + } + + copy = strtol(n1, NULL, 10); + if (copy > SD_MAX_COPIES || copy < 1) { + return -EINVAL; + } + if (!n2) { + inode->copy_policy = 0; + inode->nr_copies = copy; + return 0; + } + + if (copy != 2 && copy != 4 && copy != 8 && copy != 16) { + return -EINVAL; + } + + parity = strtol(n2, NULL, 10); + if (parity >= SD_EC_MAX_STRIP || parity < 1) { + return -EINVAL; + } + + /* + * 4 bits for parity and 4 bits for data. + * We have to compress upper data bits because it can't represent 16 + */ + inode->copy_policy = ((copy / 2) << 4) + parity; + inode->nr_copies = copy + parity; + + return 0; +} + +static int parse_block_size_shift(BDRVSheepdogState *s, QemuOpts *opt) +{ + struct SheepdogInode *inode = &s->inode; + uint64_t object_size; + int obj_order; + + object_size = qemu_opt_get_size_del(opt, BLOCK_OPT_OBJECT_SIZE, 0); + if (object_size) { + if ((object_size - 1) & object_size) { /* not a power of 2? */ + return -EINVAL; + } + obj_order = ctz32(object_size); + if (obj_order < 20 || obj_order > 31) { + return -EINVAL; + } + inode->block_size_shift = (uint8_t)obj_order; + } + + return 0; +} + +static int sd_create(const char *filename, QemuOpts *opts, + Error **errp) +{ + int ret = 0; + uint32_t vid = 0; + char *backing_file = NULL; + char *buf = NULL; + BDRVSheepdogState *s; + char tag[SD_MAX_VDI_TAG_LEN]; + uint32_t snapid; + uint64_t max_vdi_size; + bool prealloc = false; + + s = g_new0(BDRVSheepdogState, 1); + + memset(tag, 0, sizeof(tag)); + if (strstr(filename, "://")) { + ret = sd_parse_uri(s, filename, s->name, &snapid, tag); + } else { + ret = parse_vdiname(s, filename, s->name, &snapid, tag); + } + if (ret < 0) { + error_setg(errp, "Can't parse filename"); + goto out; + } + + s->inode.vdi_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), + BDRV_SECTOR_SIZE); + backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); + buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); + if (!buf || !strcmp(buf, "off")) { + prealloc = false; + } else if (!strcmp(buf, "full")) { + prealloc = true; + } else { + error_setg(errp, "Invalid preallocation mode: '%s'", buf); + ret = -EINVAL; + goto out; + } + + g_free(buf); + buf = qemu_opt_get_del(opts, BLOCK_OPT_REDUNDANCY); + if (buf) { + ret = parse_redundancy(s, buf); + if (ret < 0) { + error_setg(errp, "Invalid redundancy mode: '%s'", buf); + goto out; + } + } + ret = parse_block_size_shift(s, opts); + if (ret < 0) { + error_setg(errp, "Invalid object_size." + " obect_size needs to be power of 2" + " and be limited from 2^20 to 2^31"); + goto out; + } + + if (backing_file) { + BlockDriverState *bs; + BDRVSheepdogState *base; + BlockDriver *drv; + + /* Currently, only Sheepdog backing image is supported. */ + drv = bdrv_find_protocol(backing_file, true, NULL); + if (!drv || strcmp(drv->protocol_name, "sheepdog") != 0) { + error_setg(errp, "backing_file must be a sheepdog image"); + ret = -EINVAL; + goto out; + } + + bs = NULL; + ret = bdrv_open(&bs, backing_file, NULL, NULL, BDRV_O_PROTOCOL, errp); + if (ret < 0) { + goto out; + } + + base = bs->opaque; + + if (!is_snapshot(&base->inode)) { + error_setg(errp, "cannot clone from a non snapshot vdi"); + bdrv_unref(bs); + ret = -EINVAL; + goto out; + } + s->inode.vdi_id = base->inode.vdi_id; + bdrv_unref(bs); + } + + s->aio_context = qemu_get_aio_context(); + + /* if block_size_shift is not specified, get cluster default value */ + if (s->inode.block_size_shift == 0) { + SheepdogVdiReq hdr; + SheepdogClusterRsp *rsp = (SheepdogClusterRsp *)&hdr; + Error *local_err = NULL; + int fd; + unsigned int wlen = 0, rlen = 0; + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report("%s", error_get_pretty(local_err)); + error_free(local_err); + ret = -EIO; + goto out; + } + + memset(&hdr, 0, sizeof(hdr)); + hdr.opcode = SD_OP_GET_CLUSTER_DEFAULT; + hdr.proto_ver = SD_PROTO_VER; + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr, + NULL, &wlen, &rlen); + closesocket(fd); + if (ret) { + error_setg_errno(errp, -ret, "failed to get cluster default"); + goto out; + } + if (rsp->result == SD_RES_SUCCESS) { + s->inode.block_size_shift = rsp->block_size_shift; + } else { + s->inode.block_size_shift = SD_DEFAULT_BLOCK_SIZE_SHIFT; + } + } + + max_vdi_size = (UINT64_C(1) << s->inode.block_size_shift) * MAX_DATA_OBJS; + + if (s->inode.vdi_size > max_vdi_size) { + error_setg(errp, "An image is too large." + " The maximum image size is %"PRIu64 "GB", + max_vdi_size / 1024 / 1024 / 1024); + ret = -EINVAL; + goto out; + } + + ret = do_sd_create(s, &vid, 0, errp); + if (ret) { + goto out; + } + + if (prealloc) { + ret = sd_prealloc(filename, errp); + } +out: + g_free(backing_file); + g_free(buf); + g_free(s); + return ret; +} + +static void sd_close(BlockDriverState *bs) +{ + Error *local_err = NULL; + BDRVSheepdogState *s = bs->opaque; + SheepdogVdiReq hdr; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + unsigned int wlen, rlen = 0; + int fd, ret; + + DPRINTF("%s\n", s->name); + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + return; + } + + memset(&hdr, 0, sizeof(hdr)); + + hdr.opcode = SD_OP_RELEASE_VDI; + hdr.type = LOCK_TYPE_NORMAL; + hdr.base_vdi_id = s->inode.vdi_id; + wlen = strlen(s->name) + 1; + hdr.data_length = wlen; + hdr.flags = SD_FLAG_CMD_WRITE; + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr, + s->name, &wlen, &rlen); + + closesocket(fd); + + if (!ret && rsp->result != SD_RES_SUCCESS && + rsp->result != SD_RES_VDI_NOT_LOCKED) { + error_report("%s, %s", sd_strerror(rsp->result), s->name); + } + + aio_set_fd_handler(bdrv_get_aio_context(bs), s->fd, + false, NULL, NULL, NULL); + closesocket(s->fd); + g_free(s->host_spec); +} + +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) +{ + Error *local_err = NULL; + BDRVSheepdogState *s = bs->opaque; + int ret, fd; + unsigned int datalen; + uint64_t max_vdi_size; + + max_vdi_size = (UINT64_C(1) << s->inode.block_size_shift) * MAX_DATA_OBJS; + if (offset < s->inode.vdi_size) { + error_report("shrinking is not supported"); + return -EINVAL; + } else if (offset > max_vdi_size) { + error_report("too big image size"); + return -EINVAL; + } + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + return fd; + } + + /* 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, s->aio_context, (char *)&s->inode, + vid_to_vdi_oid(s->inode.vdi_id), s->inode.nr_copies, + datalen, 0, false, s->cache_flags); + close(fd); + + if (ret < 0) { + error_report("failed to update an inode."); + } + + return ret; +} + +/* + * 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 coroutine_fn sd_write_done(SheepdogAIOCB *acb) +{ + BDRVSheepdogState *s = acb->common.bs->opaque; + struct iovec iov; + AIOReq *aio_req; + uint32_t offset, data_len, mn, mx; + + mn = acb->min_dirty_data_idx; + mx = acb->max_dirty_data_idx; + if (mn <= mx) { + /* we need to update the vdi object. */ + offset = sizeof(s->inode) - sizeof(s->inode.data_vdi_id) + + mn * sizeof(s->inode.data_vdi_id[0]); + data_len = (mx - mn + 1) * sizeof(s->inode.data_vdi_id[0]); + + acb->min_dirty_data_idx = UINT32_MAX; + acb->max_dirty_data_idx = 0; + + iov.iov_base = &s->inode; + iov.iov_len = sizeof(s->inode); + aio_req = alloc_aio_req(s, acb, vid_to_vdi_oid(s->inode.vdi_id), + data_len, offset, 0, false, 0, offset); + QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings); + add_aio_request(s, aio_req, &iov, 1, AIOCB_WRITE_UDATA); + + acb->aio_done_func = sd_finish_aiocb; + acb->aiocb_type = AIOCB_WRITE_UDATA; + return; + } + + sd_finish_aiocb(acb); +} + +/* Delete current working VDI on the snapshot chain */ +static bool sd_delete(BDRVSheepdogState *s) +{ + Error *local_err = NULL; + unsigned int wlen = SD_MAX_VDI_LEN, rlen = 0; + SheepdogVdiReq hdr = { + .opcode = SD_OP_DEL_VDI, + .base_vdi_id = s->inode.vdi_id, + .data_length = wlen, + .flags = SD_FLAG_CMD_WRITE, + }; + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr; + int fd, ret; + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + return false; + } + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr, + s->name, &wlen, &rlen); + closesocket(fd); + if (ret) { + return false; + } + switch (rsp->result) { + case SD_RES_NO_VDI: + error_report("%s was already deleted", s->name); + /* fall through */ + case SD_RES_SUCCESS: + break; + default: + error_report("%s, %s", sd_strerror(rsp->result), s->name); + return false; + } + + return true; +} + +/* + * Create a writable VDI from a snapshot + */ +static int sd_create_branch(BDRVSheepdogState *s) +{ + Error *local_err = NULL; + int ret, fd; + uint32_t vid; + char *buf; + bool deleted; + + DPRINTF("%" PRIx32 " is snapshot.\n", s->inode.vdi_id); + + buf = g_malloc(SD_INODE_SIZE); + + /* + * Even If deletion fails, we will just create extra snapshot based on + * the working VDI which was supposed to be deleted. So no need to + * false bail out. + */ + deleted = sd_delete(s); + ret = do_sd_create(s, &vid, !deleted, &local_err); + if (ret) { + error_report_err(local_err); + goto out; + } + + DPRINTF("%" PRIx32 " is created.\n", vid); + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + ret = fd; + goto out; + } + + ret = read_object(fd, s->aio_context, buf, vid_to_vdi_oid(vid), + s->inode.nr_copies, SD_INODE_SIZE, 0, s->cache_flags); + + closesocket(fd); + + if (ret < 0) { + goto out; + } + + memcpy(&s->inode, buf, sizeof(s->inode)); + + s->is_snapshot = false; + ret = 0; + 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 inflight_list in BDRVSheepdogState, and exits without + * waiting the response. The responses are received in the + * `aio_read_response' function which is called from the main loop as + * a fd handler. + * + * Returns 1 when we need to wait a response, 0 when there is no sent + * request and -errno in error cases. + */ +static int coroutine_fn sd_co_rw_vector(void *p) +{ + SheepdogAIOCB *acb = p; + int ret = 0; + unsigned long len, done = 0, total = acb->nb_sectors * BDRV_SECTOR_SIZE; + unsigned long idx; + uint32_t object_size; + uint64_t oid; + uint64_t offset; + BDRVSheepdogState *s = acb->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; + } + } + + object_size = (UINT32_C(1) << inode->block_size_shift); + idx = acb->sector_num * BDRV_SECTOR_SIZE / object_size; + offset = (acb->sector_num * BDRV_SECTOR_SIZE) % object_size; + + /* + * Make sure we don't free the aiocb before we are done with all requests. + * This additional reference is dropped at the end of this function. + */ + acb->nr_pending++; + + while (done != total) { + uint8_t flags = 0; + uint64_t old_oid = 0; + bool create = false; + + oid = vid_to_data_oid(inode->data_vdi_id[idx], idx); + + len = MIN(total - done, object_size - offset); + + switch (acb->aiocb_type) { + case AIOCB_READ_UDATA: + if (!inode->data_vdi_id[idx]) { + qemu_iovec_memset(acb->qiov, done, 0, len); + goto done; + } + break; + case AIOCB_WRITE_UDATA: + if (!inode->data_vdi_id[idx]) { + create = true; + } else if (!is_data_obj_writable(inode, idx)) { + /* Copy-On-Write */ + create = true; + old_oid = oid; + flags = SD_FLAG_CMD_COW; + } + break; + case AIOCB_DISCARD_OBJ: + /* + * We discard the object only when the whole object is + * 1) allocated 2) trimmed. Otherwise, simply skip it. + */ + if (len != object_size || inode->data_vdi_id[idx] == 0) { + goto done; + } + break; + default: + break; + } + + if (create) { + DPRINTF("update ino (%" PRIu32 ") %" PRIu64 " %" PRIu64 " %ld\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 %" PRIx64 "\n", oid); + } + + aio_req = alloc_aio_req(s, acb, oid, len, offset, flags, create, + old_oid, + acb->aiocb_type == AIOCB_DISCARD_OBJ ? + 0 : done); + QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings); + + add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, + acb->aiocb_type); + done: + offset = 0; + idx++; + done += len; + } +out: + if (!--acb->nr_pending) { + return acb->ret; + } + return 1; +} + +static bool check_overlapping_aiocb(BDRVSheepdogState *s, SheepdogAIOCB *aiocb) +{ + SheepdogAIOCB *cb; + + QLIST_FOREACH(cb, &s->inflight_aiocb_head, aiocb_siblings) { + if (AIOCBOverlapping(aiocb, cb)) { + return true; + } + } + + QLIST_INSERT_HEAD(&s->inflight_aiocb_head, aiocb, aiocb_siblings); + return false; +} + +static coroutine_fn int sd_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + SheepdogAIOCB *acb; + int ret; + int64_t offset = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE; + BDRVSheepdogState *s = bs->opaque; + + if (offset > s->inode.vdi_size) { + ret = sd_truncate(bs, offset); + if (ret < 0) { + return ret; + } + } + + acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors); + acb->aio_done_func = sd_write_done; + acb->aiocb_type = AIOCB_WRITE_UDATA; + +retry: + if (check_overlapping_aiocb(s, acb)) { + qemu_co_queue_wait(&s->overlapping_queue); + goto retry; + } + + ret = sd_co_rw_vector(acb); + if (ret <= 0) { + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + qemu_aio_unref(acb); + return ret; + } + + qemu_coroutine_yield(); + + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + + return acb->ret; +} + +static coroutine_fn int sd_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + SheepdogAIOCB *acb; + int ret; + BDRVSheepdogState *s = bs->opaque; + + acb = sd_aio_setup(bs, qiov, sector_num, nb_sectors); + acb->aiocb_type = AIOCB_READ_UDATA; + acb->aio_done_func = sd_finish_aiocb; + +retry: + if (check_overlapping_aiocb(s, acb)) { + qemu_co_queue_wait(&s->overlapping_queue); + goto retry; + } + + ret = sd_co_rw_vector(acb); + if (ret <= 0) { + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + qemu_aio_unref(acb); + return ret; + } + + qemu_coroutine_yield(); + + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + return acb->ret; +} + +static int coroutine_fn sd_co_flush_to_disk(BlockDriverState *bs) +{ + BDRVSheepdogState *s = bs->opaque; + SheepdogAIOCB *acb; + AIOReq *aio_req; + + if (s->cache_flags != SD_FLAG_CMD_CACHE) { + return 0; + } + + acb = sd_aio_setup(bs, NULL, 0, 0); + acb->aiocb_type = AIOCB_FLUSH_CACHE; + acb->aio_done_func = sd_finish_aiocb; + + aio_req = alloc_aio_req(s, acb, vid_to_vdi_oid(s->inode.vdi_id), + 0, 0, 0, false, 0, 0); + QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings); + add_aio_request(s, aio_req, NULL, 0, acb->aiocb_type); + + qemu_coroutine_yield(); + return acb->ret; +} + +static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) +{ + Error *local_err = NULL; + BDRVSheepdogState *s = bs->opaque; + int ret, fd; + uint32_t new_vid; + SheepdogInode *inode; + unsigned int datalen; + + DPRINTF("sn_info: name %s id_str %s s: name %s vm_state_size %" PRId64 " " + "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; + /* It appears that inode.tag does not require a NUL terminator, + * which means this use of strncpy is ok. + */ + strncpy(s->inode.tag, sn_info->name, sizeof(s->inode.tag)); + /* we don't need to update entire object */ + datalen = SD_INODE_SIZE - sizeof(s->inode.data_vdi_id); + inode = g_malloc(datalen); + + /* refresh inode. */ + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + ret = fd; + goto cleanup; + } + + ret = write_object(fd, s->aio_context, (char *)&s->inode, + vid_to_vdi_oid(s->inode.vdi_id), s->inode.nr_copies, + datalen, 0, false, s->cache_flags); + if (ret < 0) { + error_report("failed to write snapshot's inode."); + goto cleanup; + } + + ret = do_sd_create(s, &new_vid, 1, &local_err); + if (ret < 0) { + error_report("failed to create inode for snapshot: %s", + error_get_pretty(local_err)); + error_free(local_err); + goto cleanup; + } + + ret = read_object(fd, s->aio_context, (char *)inode, + vid_to_vdi_oid(new_vid), s->inode.nr_copies, datalen, 0, + s->cache_flags); + + if (ret < 0) { + error_report("failed to read new inode info. %s", strerror(errno)); + goto cleanup; + } + + memcpy(&s->inode, inode, datalen); + DPRINTF("s->inode: name %s snap_id %x oid %x\n", + s->inode.name, s->inode.snap_id, s->inode.vdi_id); + +cleanup: + g_free(inode); + closesocket(fd); + return ret; +} + +/* + * We implement rollback(loadvm) operation to the specified snapshot by + * 1) switch to the snapshot + * 2) rely on sd_create_branch to delete working VDI and + * 3) create a new working VDI based on the specified snapshot + */ +static int sd_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) +{ + BDRVSheepdogState *s = bs->opaque; + BDRVSheepdogState *old_s; + char tag[SD_MAX_VDI_TAG_LEN]; + uint32_t snapid = 0; + int ret = 0; + + old_s = g_new(BDRVSheepdogState, 1); + + memcpy(old_s, s, sizeof(BDRVSheepdogState)); + + snapid = strtoul(snapshot_id, NULL, 10); + if (snapid) { + tag[0] = 0; + } else { + pstrcpy(tag, sizeof(tag), snapshot_id); + } + + ret = reload_inode(s, snapid, tag); + if (ret) { + goto out; + } + + ret = sd_create_branch(s); + if (ret) { + goto out; + } + + g_free(old_s); + + return 0; +out: + /* recover bdrv_sd_state */ + memcpy(s, old_s, sizeof(BDRVSheepdogState)); + g_free(old_s); + + error_report("failed to open. recover old bdrv_sd_state."); + + return ret; +} + +static int sd_snapshot_delete(BlockDriverState *bs, + const char *snapshot_id, + const char *name, + Error **errp) +{ + /* FIXME: Delete specified snapshot id. */ + return 0; +} + +static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) +{ + Error *local_err = NULL; + BDRVSheepdogState *s = bs->opaque; + SheepdogReq req; + int fd, nr = 1024, ret, max = BITS_TO_LONGS(SD_NR_VDIS) * sizeof(long); + QEMUSnapshotInfo *sn_tab = NULL; + unsigned wlen, rlen; + int found = 0; + 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, &local_err); + if (fd < 0) { + error_report_err(local_err); + ret = fd; + goto out; + } + + rlen = max; + wlen = 0; + + memset(&req, 0, sizeof(req)); + + req.opcode = SD_OP_READ_VDIS; + req.data_length = max; + + ret = do_req(fd, s->aio_context, (SheepdogReq *)&req, + vdi_inuse, &wlen, &rlen); + + closesocket(fd); + if (ret) { + goto out; + } + + sn_tab = g_new0(QEMUSnapshotInfo, nr); + + /* calculate a vdi id with hash function */ + hval = fnv_64a_buf(s->name, strlen(s->name), FNV1A_64_INIT); + start_nr = hval & (SD_NR_VDIS - 1); + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + ret = fd; + goto out; + } + + for (vid = start_nr; found < nr; vid = (vid + 1) % SD_NR_VDIS) { + if (!test_bit(vid, vdi_inuse)) { + break; + } + + /* we don't need to read entire object */ + ret = read_object(fd, s->aio_context, (char *)&inode, + vid_to_vdi_oid(vid), + 0, SD_INODE_SIZE - sizeof(inode.data_vdi_id), 0, + s->cache_flags); + + if (ret) { + continue; + } + + if (!strcmp(inode.name, s->name) && is_snapshot(&inode)) { + sn_tab[found].date_sec = inode.snap_ctime >> 32; + sn_tab[found].date_nsec = inode.snap_ctime & 0xffffffff; + sn_tab[found].vm_state_size = inode.vm_state_size; + sn_tab[found].vm_clock_nsec = inode.vm_clock_nsec; + + snprintf(sn_tab[found].id_str, sizeof(sn_tab[found].id_str), + "%" PRIu32, inode.snap_id); + pstrcpy(sn_tab[found].name, + MIN(sizeof(sn_tab[found].name), sizeof(inode.tag)), + inode.tag); + found++; + } + } + + closesocket(fd); +out: + *psn_tab = sn_tab; + + g_free(vdi_inuse); + + if (ret < 0) { + return ret; + } + + return found; +} + +static int do_load_save_vmstate(BDRVSheepdogState *s, uint8_t *data, + int64_t pos, int size, int load) +{ + Error *local_err = NULL; + bool create; + int fd, ret = 0, remaining = size; + unsigned int data_len; + uint64_t vmstate_oid; + uint64_t offset; + uint32_t vdi_index; + uint32_t vdi_id = load ? s->inode.parent_vdi_id : s->inode.vdi_id; + uint32_t object_size = (UINT32_C(1) << s->inode.block_size_shift); + + fd = connect_to_sdog(s, &local_err); + if (fd < 0) { + error_report_err(local_err); + return fd; + } + + while (remaining) { + vdi_index = pos / object_size; + offset = pos % object_size; + + data_len = MIN(remaining, object_size - offset); + + vmstate_oid = vid_to_vmstate_oid(vdi_id, vdi_index); + + create = (offset == 0); + if (load) { + ret = read_object(fd, s->aio_context, (char *)data, vmstate_oid, + s->inode.nr_copies, data_len, offset, + s->cache_flags); + } else { + ret = write_object(fd, s->aio_context, (char *)data, vmstate_oid, + s->inode.nr_copies, data_len, offset, create, + s->cache_flags); + } + + if (ret < 0) { + error_report("failed to save vmstate %s", strerror(errno)); + goto cleanup; + } + + pos += data_len; + data += data_len; + remaining -= data_len; + } + ret = size; +cleanup: + closesocket(fd); + return ret; +} + +static int sd_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, + int64_t pos) +{ + BDRVSheepdogState *s = bs->opaque; + void *buf; + int ret; + + buf = qemu_blockalign(bs, qiov->size); + qemu_iovec_to_buf(qiov, 0, buf, qiov->size); + ret = do_load_save_vmstate(s, (uint8_t *) buf, pos, qiov->size, 0); + qemu_vfree(buf); + + return ret; +} + +static int sd_load_vmstate(BlockDriverState *bs, uint8_t *data, + int64_t pos, int size) +{ + BDRVSheepdogState *s = bs->opaque; + + return do_load_save_vmstate(s, data, pos, size, 1); +} + + +static coroutine_fn int sd_co_discard(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) +{ + SheepdogAIOCB *acb; + BDRVSheepdogState *s = bs->opaque; + int ret; + QEMUIOVector discard_iov; + struct iovec iov; + uint32_t zero = 0; + + if (!s->discard_supported) { + return 0; + } + + memset(&discard_iov, 0, sizeof(discard_iov)); + memset(&iov, 0, sizeof(iov)); + iov.iov_base = &zero; + iov.iov_len = sizeof(zero); + discard_iov.iov = &iov; + discard_iov.niov = 1; + acb = sd_aio_setup(bs, &discard_iov, sector_num, nb_sectors); + acb->aiocb_type = AIOCB_DISCARD_OBJ; + acb->aio_done_func = sd_finish_aiocb; + +retry: + if (check_overlapping_aiocb(s, acb)) { + qemu_co_queue_wait(&s->overlapping_queue); + goto retry; + } + + ret = sd_co_rw_vector(acb); + if (ret <= 0) { + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + qemu_aio_unref(acb); + return ret; + } + + qemu_coroutine_yield(); + + QLIST_REMOVE(acb, aiocb_siblings); + qemu_co_queue_restart_all(&s->overlapping_queue); + + return acb->ret; +} + +static coroutine_fn int64_t +sd_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors, + int *pnum) +{ + BDRVSheepdogState *s = bs->opaque; + SheepdogInode *inode = &s->inode; + uint32_t object_size = (UINT32_C(1) << inode->block_size_shift); + uint64_t offset = sector_num * BDRV_SECTOR_SIZE; + unsigned long start = offset / object_size, + end = DIV_ROUND_UP((sector_num + nb_sectors) * + BDRV_SECTOR_SIZE, object_size); + unsigned long idx; + int64_t ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; + + for (idx = start; idx < end; idx++) { + if (inode->data_vdi_id[idx] == 0) { + break; + } + } + if (idx == start) { + /* Get the longest length of unallocated sectors */ + ret = 0; + for (idx = start + 1; idx < end; idx++) { + if (inode->data_vdi_id[idx] != 0) { + break; + } + } + } + + *pnum = (idx - start) * object_size / BDRV_SECTOR_SIZE; + if (*pnum > nb_sectors) { + *pnum = nb_sectors; + } + return ret; +} + +static int64_t sd_get_allocated_file_size(BlockDriverState *bs) +{ + BDRVSheepdogState *s = bs->opaque; + SheepdogInode *inode = &s->inode; + uint32_t object_size = (UINT32_C(1) << inode->block_size_shift); + unsigned long i, last = DIV_ROUND_UP(inode->vdi_size, object_size); + uint64_t size = 0; + + for (i = 0; i < last; i++) { + if (inode->data_vdi_id[i] == 0) { + continue; + } + size += object_size; + } + return size; +} + +static QemuOptsList sd_create_opts = { + .name = "sheepdog-create-opts", + .head = QTAILQ_HEAD_INITIALIZER(sd_create_opts.head), + .desc = { + { + .name = BLOCK_OPT_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Virtual disk size" + }, + { + .name = BLOCK_OPT_BACKING_FILE, + .type = QEMU_OPT_STRING, + .help = "File name of a base image" + }, + { + .name = BLOCK_OPT_PREALLOC, + .type = QEMU_OPT_STRING, + .help = "Preallocation mode (allowed values: off, full)" + }, + { + .name = BLOCK_OPT_REDUNDANCY, + .type = QEMU_OPT_STRING, + .help = "Redundancy of the image" + }, + { + .name = BLOCK_OPT_OBJECT_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Object size of the image" + }, + { /* end of list */ } + } +}; + +static BlockDriver bdrv_sheepdog = { + .format_name = "sheepdog", + .protocol_name = "sheepdog", + .instance_size = sizeof(BDRVSheepdogState), + .bdrv_needs_filename = true, + .bdrv_file_open = sd_open, + .bdrv_reopen_prepare = sd_reopen_prepare, + .bdrv_reopen_commit = sd_reopen_commit, + .bdrv_reopen_abort = sd_reopen_abort, + .bdrv_close = sd_close, + .bdrv_create = sd_create, + .bdrv_has_zero_init = bdrv_has_zero_init_1, + .bdrv_getlength = sd_getlength, + .bdrv_get_allocated_file_size = sd_get_allocated_file_size, + .bdrv_truncate = sd_truncate, + + .bdrv_co_readv = sd_co_readv, + .bdrv_co_writev = sd_co_writev, + .bdrv_co_flush_to_disk = sd_co_flush_to_disk, + .bdrv_co_discard = sd_co_discard, + .bdrv_co_get_block_status = sd_co_get_block_status, + + .bdrv_snapshot_create = sd_snapshot_create, + .bdrv_snapshot_goto = sd_snapshot_goto, + .bdrv_snapshot_delete = sd_snapshot_delete, + .bdrv_snapshot_list = sd_snapshot_list, + + .bdrv_save_vmstate = sd_save_vmstate, + .bdrv_load_vmstate = sd_load_vmstate, + + .bdrv_detach_aio_context = sd_detach_aio_context, + .bdrv_attach_aio_context = sd_attach_aio_context, + + .create_opts = &sd_create_opts, +}; + +static BlockDriver bdrv_sheepdog_tcp = { + .format_name = "sheepdog", + .protocol_name = "sheepdog+tcp", + .instance_size = sizeof(BDRVSheepdogState), + .bdrv_needs_filename = true, + .bdrv_file_open = sd_open, + .bdrv_reopen_prepare = sd_reopen_prepare, + .bdrv_reopen_commit = sd_reopen_commit, + .bdrv_reopen_abort = sd_reopen_abort, + .bdrv_close = sd_close, + .bdrv_create = sd_create, + .bdrv_has_zero_init = bdrv_has_zero_init_1, + .bdrv_getlength = sd_getlength, + .bdrv_get_allocated_file_size = sd_get_allocated_file_size, + .bdrv_truncate = sd_truncate, + + .bdrv_co_readv = sd_co_readv, + .bdrv_co_writev = sd_co_writev, + .bdrv_co_flush_to_disk = sd_co_flush_to_disk, + .bdrv_co_discard = sd_co_discard, + .bdrv_co_get_block_status = sd_co_get_block_status, + + .bdrv_snapshot_create = sd_snapshot_create, + .bdrv_snapshot_goto = sd_snapshot_goto, + .bdrv_snapshot_delete = sd_snapshot_delete, + .bdrv_snapshot_list = sd_snapshot_list, + + .bdrv_save_vmstate = sd_save_vmstate, + .bdrv_load_vmstate = sd_load_vmstate, + + .bdrv_detach_aio_context = sd_detach_aio_context, + .bdrv_attach_aio_context = sd_attach_aio_context, + + .create_opts = &sd_create_opts, +}; + +static BlockDriver bdrv_sheepdog_unix = { + .format_name = "sheepdog", + .protocol_name = "sheepdog+unix", + .instance_size = sizeof(BDRVSheepdogState), + .bdrv_needs_filename = true, + .bdrv_file_open = sd_open, + .bdrv_reopen_prepare = sd_reopen_prepare, + .bdrv_reopen_commit = sd_reopen_commit, + .bdrv_reopen_abort = sd_reopen_abort, + .bdrv_close = sd_close, + .bdrv_create = sd_create, + .bdrv_has_zero_init = bdrv_has_zero_init_1, + .bdrv_getlength = sd_getlength, + .bdrv_get_allocated_file_size = sd_get_allocated_file_size, + .bdrv_truncate = sd_truncate, + + .bdrv_co_readv = sd_co_readv, + .bdrv_co_writev = sd_co_writev, + .bdrv_co_flush_to_disk = sd_co_flush_to_disk, + .bdrv_co_discard = sd_co_discard, + .bdrv_co_get_block_status = sd_co_get_block_status, + + .bdrv_snapshot_create = sd_snapshot_create, + .bdrv_snapshot_goto = sd_snapshot_goto, + .bdrv_snapshot_delete = sd_snapshot_delete, + .bdrv_snapshot_list = sd_snapshot_list, + + .bdrv_save_vmstate = sd_save_vmstate, + .bdrv_load_vmstate = sd_load_vmstate, + + .bdrv_detach_aio_context = sd_detach_aio_context, + .bdrv_attach_aio_context = sd_attach_aio_context, + + .create_opts = &sd_create_opts, +}; + +static void bdrv_sheepdog_init(void) +{ + bdrv_register(&bdrv_sheepdog); + bdrv_register(&bdrv_sheepdog_tcp); + bdrv_register(&bdrv_sheepdog_unix); +} +block_init(bdrv_sheepdog_init); |
