@@ -27,6 +27,8 @@
#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
@@ -269,6 +271,7 @@ enum AIOCBState {
AIOCB_WRITE_UDATA,
AIOCB_READ_UDATA,
AIOCB_FLUSH_CACHE,
+ AIOCB_DISCARD_OBJ,
};
struct SheepdogAIOCB {
@@ -298,6 +301,7 @@ typedef struct BDRVSheepdogState {
char name[SD_MAX_VDI_LEN];
bool is_snapshot;
uint32_t cache_flags;
+ bool discard_supported;
char *host_spec;
bool is_unix;
@@ -656,7 +660,7 @@ static void coroutine_fn aio_read_response(void *opaque)
int ret;
AIOReq *aio_req = NULL;
SheepdogAIOCB *acb;
- unsigned long idx;
+ uint64_t idx;
if (QLIST_EMPTY(&s->inflight_aio_head)) {
goto out;
@@ -727,6 +731,21 @@ static void coroutine_fn aio_read_response(void *opaque)
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;
+ }
}
if (rsp.result != SD_RES_SUCCESS) {
@@ -1016,6 +1035,9 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
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) {
@@ -1170,6 +1192,7 @@ static int sd_open(BlockDriverState *bs, const char *filename,
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);
@@ -1633,6 +1656,15 @@ static int coroutine_fn sd_co_rw_vector(void *p)
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 != SD_DATA_OBJ_SIZE || inode->data_vdi_id[idx] == 0) {
+ goto done;
+ }
+ break;
default:
break;
}
@@ -2078,6 +2110,33 @@ static int sd_load_vmstate(BlockDriverState *bs, uint8_t *data,
}
+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;
+
+ ret = sd_co_rw_vector(acb);
+ if (ret <= 0) {
+ qemu_aio_release(acb);
+ return ret;
+ }
+
+ qemu_coroutine_yield();
+
+ return acb->ret;
+}
+
static QEMUOptionParameter sd_create_options[] = {
{
.name = BLOCK_OPT_SIZE,
@@ -2110,6 +2169,7 @@ static 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_co_discard = sd_co_discard,
.bdrv_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
@@ -2135,6 +2195,7 @@ static BlockDriver bdrv_sheepdog_tcp = {
.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_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
@@ -2160,6 +2221,7 @@ static BlockDriver bdrv_sheepdog_unix = {
.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_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,