--- /dev/null
+/*
+ * 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_DISCARD_OBJ 0x05
+
+#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 AIOCBOverwrapping(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;
+
+ QLIST_ENTRY(SheepdogAIOCB) aiocb_siblings;
+};
+
+typedef struct BDRVSheepdogState {
+ BlockDriverState *bs;
+ AioContext *aio_context;
+
+ SheepdogInode inode;
+
+ uint32_t min_dirty_data_idx;
+ uint32_t max_dirty_data_idx;
+
+ 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 overwrapping_queue;
+ QLIST_HEAD(inflight_aiocb_head, SheepdogAIOCB) inflight_aiocb_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"},
+ {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;
+
+ 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, 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, 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, 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, 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;
+ s->max_dirty_data_idx = MAX(idx, s->max_dirty_data_idx);
+ s->min_dirty_data_idx = MIN(idx, s->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;
+ case SD_RES_SUCCESS:
+ idx = data_oid_to_idx(aio_req->oid);
+ s->inode.data_vdi_id[idx] = 0;
+ 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, 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_DISCARD_OBJ;
+ 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,
+ 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, 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, 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, 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));
+ s->min_dirty_data_idx = UINT32_MAX;
+ s->max_dirty_data_idx = 0;
+
+ 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->overwrapping_queue);
+ qemu_opts_del(opts);
+ g_free(buf);
+ return 0;
+out:
+ aio_set_fd_handler(bdrv_get_aio_context(bs), s->fd, NULL, NULL, NULL);
+ if (s->fd >= 0) {
+ closesocket(s->fd);
+ }
+ qemu_opts_del(opts);
+ g_free(buf);
+ return ret;
+}
+
+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,
+ NULL, 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, NULL,
+ 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, 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 = 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, 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, 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_overwrapping_aiocb(BDRVSheepdogState *s, SheepdogAIOCB *aiocb)
+{
+ SheepdogAIOCB *cb;
+
+ QLIST_FOREACH(cb, &s->inflight_aiocb_head, aiocb_siblings) {
+ if (AIOCBOverwrapping(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_overwrapping_aiocb(s, acb)) {
+ qemu_co_queue_wait(&s->overwrapping_queue);
+ goto retry;
+ }
+
+ ret = sd_co_rw_vector(acb);
+ if (ret <= 0) {
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_queue);
+ qemu_aio_unref(acb);
+ return ret;
+ }
+
+ qemu_coroutine_yield();
+
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_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_overwrapping_aiocb(s, acb)) {
+ qemu_co_queue_wait(&s->overwrapping_queue);
+ goto retry;
+ }
+
+ ret = sd_co_rw_vector(acb);
+ if (ret <= 0) {
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_queue);
+ qemu_aio_unref(acb);
+ return ret;
+ }
+
+ qemu_coroutine_yield();
+
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_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;
+ QEMUIOVector dummy;
+ BDRVSheepdogState *s = bs->opaque;
+ int ret;
+
+ if (!s->discard_supported) {
+ return 0;
+ }
+
+ acb = sd_aio_setup(bs, &dummy, sector_num, nb_sectors);
+ acb->aiocb_type = AIOCB_DISCARD_OBJ;
+ acb->aio_done_func = sd_finish_aiocb;
+
+retry:
+ if (check_overwrapping_aiocb(s, acb)) {
+ qemu_co_queue_wait(&s->overwrapping_queue);
+ goto retry;
+ }
+
+ ret = sd_co_rw_vector(acb);
+ if (ret <= 0) {
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_queue);
+ qemu_aio_unref(acb);
+ return ret;
+ }
+
+ qemu_coroutine_yield();
+
+ QLIST_REMOVE(acb, aiocb_siblings);
+ qemu_co_queue_restart_all(&s->overwrapping_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_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_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_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);
Code Review / kvmfornfv.git / blobdiff