From: Liu Yuan <tailai...@taobao.com>
Flush operation is supposed to flush the write-back cache of
sheepdog cluster.
By issuing flush operation, we can assure the Guest of data
reaching the sheepdog cluster storage.
Cc: Kevin Wolf <kw...@redhat.com>
Reviewd-by: MORITA Kazutaka <morita.kazut...@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai...@taobao.com>
---
block/sheepdog.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 00276f6f..c08c69b 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -32,9 +32,11 @@
#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_FLAG_CMD_WRITE 0x01
#define SD_FLAG_CMD_COW 0x02
+#define SD_FLAG_CMD_CACHE 0x04
#define SD_RES_SUCCESS 0x00 /* Success */
#define SD_RES_UNKNOWN 0x01 /* Unknown error */
@@ -179,6 +181,8 @@ typedef struct SheepdogInode {
uint32_t data_vdi_id[MAX_DATA_OBJS];
} SheepdogInode;
+static int cache_enabled;
+
/*
* 64 bit FNV-1a non-zero initial basis
*/
@@ -900,6 +904,10 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState
*s, AIOReq *aio_req,
hdr.flags = SD_FLAG_CMD_WRITE | flags;
}
+ if (cache_enabled) {
+ hdr.flags |= SD_FLAG_CMD_CACHE;
+ }
+
hdr.oid = oid;
hdr.cow_oid = old_oid;
hdr.copies = s->inode.nr_copies;
@@ -965,6 +973,11 @@ static int read_write_object(int fd, char *buf, uint64_t
oid, int copies,
rlen = datalen;
hdr.opcode = SD_OP_READ_OBJ;
}
+
+ if (cache_enabled) {
+ hdr.flags |= SD_FLAG_CMD_CACHE;
+ }
+
hdr.oid = oid;
hdr.data_length = datalen;
hdr.offset = offset;
@@ -1011,6 +1024,10 @@ static int sd_open(BlockDriverState *bs, const char
*filename, int flags)
QLIST_INIT(&s->outstanding_aio_head);
s->fd = -1;
+ if (flags & BDRV_O_CACHE_WB) {
+ cache_enabled = 1;
+ }
+
memset(vdi, 0, sizeof(vdi));
memset(tag, 0, sizeof(tag));
if (parse_vdiname(s, filename, vdi, &snapid, tag) < 0) {
@@ -1575,6 +1592,38 @@ static coroutine_fn int sd_co_readv(BlockDriverState
*bs, int64_t sector_num,
return acb->ret;
}
+static int coroutine_fn sd_co_flush_to_disk(BlockDriverState *bs)
+{
+ BDRVSheepdogState *s = bs->opaque;
+ SheepdogObjReq hdr = { 0 };
+ SheepdogObjRsp *rsp = (SheepdogObjRsp *)&hdr;
+ SheepdogInode *inode = &s->inode;
+ int fd, ret;
+ unsigned int wlen = 0, rlen = 0;
+
+ fd = connect_to_sdog(s->addr, s->port);
+ if (fd < 0) {
+ return -1;
+ }
+
+ hdr.opcode = SD_OP_FLUSH_VDI;
+ hdr.oid = vid_to_vdi_oid(inode->vdi_id);
+
+ ret = do_req(fd, (SheepdogReq *)&hdr, NULL, &wlen, &rlen);
+ closesocket(fd);
+ if (ret) {
+ error_report("failed to send a request to the sheep");
+ return -1;
+ }
+
+ if (rsp->result != SD_RES_SUCCESS) {
+ error_report("%s", sd_strerror(rsp->result));
+ return -1;
+ }
+
+ return 0;
+}
+
static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
{
BDRVSheepdogState *s = bs->opaque;
@@ -1904,6 +1953,7 @@ BlockDriver bdrv_sheepdog = {
.bdrv_co_readv = sd_co_readv,
.bdrv_co_writev = sd_co_writev,
+ .bdrv_co_flush_to_disk = sd_co_flush_to_disk,
.bdrv_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
--
1.7.8.2
