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-rw-r--r--block/sheepdog.c70
1 files changed, 40 insertions, 30 deletions
diff --git a/block/sheepdog.c b/block/sheepdog.c
index e821746116..462c4b2d5d 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -36,7 +36,8 @@
#define SD_FLAG_CMD_WRITE 0x01
#define SD_FLAG_CMD_COW 0x02
-#define SD_FLAG_CMD_CACHE 0x04
+#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 */
@@ -293,7 +294,7 @@ typedef struct BDRVSheepdogState {
char name[SD_MAX_VDI_LEN];
bool is_snapshot;
- bool cache_enabled;
+ uint32_t cache_flags;
char *addr;
char *port;
@@ -977,8 +978,8 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
hdr.flags = SD_FLAG_CMD_WRITE | flags;
}
- if (s->cache_enabled) {
- hdr.flags |= SD_FLAG_CMD_CACHE;
+ if (s->cache_flags) {
+ hdr.flags |= s->cache_flags;
}
hdr.oid = oid;
@@ -1023,7 +1024,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
static int read_write_object(int fd, char *buf, uint64_t oid, int copies,
unsigned int datalen, uint64_t offset,
- bool write, bool create, bool cache)
+ bool write, bool create, uint32_t cache_flags)
{
SheepdogObjReq hdr;
SheepdogObjRsp *rsp = (SheepdogObjRsp *)&hdr;
@@ -1047,9 +1048,7 @@ static int read_write_object(int fd, char *buf, uint64_t oid, int copies,
hdr.opcode = SD_OP_READ_OBJ;
}
- if (cache) {
- hdr.flags |= SD_FLAG_CMD_CACHE;
- }
+ hdr.flags |= cache_flags;
hdr.oid = oid;
hdr.data_length = datalen;
@@ -1072,18 +1071,19 @@ static int read_write_object(int fd, char *buf, uint64_t oid, int copies,
}
static int read_object(int fd, char *buf, uint64_t oid, int copies,
- unsigned int datalen, uint64_t offset, bool cache)
+ unsigned int datalen, uint64_t offset,
+ uint32_t cache_flags)
{
return read_write_object(fd, buf, oid, copies, datalen, offset, false,
- false, cache);
+ false, cache_flags);
}
static int write_object(int fd, char *buf, uint64_t oid, int copies,
unsigned int datalen, uint64_t offset, bool create,
- bool cache)
+ uint32_t cache_flags)
{
return read_write_object(fd, buf, oid, copies, datalen, offset, true,
- create, cache);
+ create, cache_flags);
}
static int sd_open(BlockDriverState *bs, const char *filename, int flags)
@@ -1118,12 +1118,22 @@ static int sd_open(BlockDriverState *bs, const char *filename, int flags)
goto out;
}
- s->cache_enabled = true;
- s->flush_fd = connect_to_sdog(s->addr, s->port);
- if (s->flush_fd < 0) {
- error_report("failed to connect");
- ret = s->flush_fd;
- 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;
+ }
+
+ if (s->cache_flags == SD_FLAG_CMD_CACHE) {
+ s->flush_fd = connect_to_sdog(s->addr, s->port);
+ if (s->flush_fd < 0) {
+ error_report("failed to connect");
+ ret = s->flush_fd;
+ goto out;
+ }
}
if (snapid || tag[0] != '\0') {
@@ -1140,7 +1150,7 @@ static int sd_open(BlockDriverState *bs, const char *filename, int flags)
buf = g_malloc(SD_INODE_SIZE);
ret = read_object(fd, buf, vid_to_vdi_oid(vid), 0, SD_INODE_SIZE, 0,
- s->cache_enabled);
+ s->cache_flags);
closesocket(fd);
@@ -1387,7 +1397,7 @@ static void sd_close(BlockDriverState *bs)
qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL, NULL);
closesocket(s->fd);
- if (s->cache_enabled) {
+ if (s->cache_flags) {
closesocket(s->flush_fd);
}
g_free(s->addr);
@@ -1423,7 +1433,7 @@ static int sd_truncate(BlockDriverState *bs, int64_t offset)
datalen = SD_INODE_SIZE - sizeof(s->inode.data_vdi_id);
s->inode.vdi_size = offset;
ret = write_object(fd, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id),
- s->inode.nr_copies, datalen, 0, false, s->cache_enabled);
+ s->inode.nr_copies, datalen, 0, false, s->cache_flags);
close(fd);
if (ret < 0) {
@@ -1506,7 +1516,7 @@ static int sd_create_branch(BDRVSheepdogState *s)
}
ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies,
- SD_INODE_SIZE, 0, s->cache_enabled);
+ SD_INODE_SIZE, 0, s->cache_flags);
closesocket(fd);
@@ -1707,7 +1717,7 @@ static int coroutine_fn sd_co_flush_to_disk(BlockDriverState *bs)
int ret;
unsigned int wlen = 0, rlen = 0;
- if (!s->cache_enabled) {
+ if (s->cache_flags != SD_FLAG_CMD_CACHE) {
return 0;
}
@@ -1723,7 +1733,7 @@ static int coroutine_fn sd_co_flush_to_disk(BlockDriverState *bs)
if (rsp->result == SD_RES_INVALID_PARMS) {
dprintf("disable write cache since the server doesn't support it\n");
- s->cache_enabled = false;
+ s->cache_flags = SD_FLAG_CMD_DIRECT;
closesocket(s->flush_fd);
return 0;
}
@@ -1774,7 +1784,7 @@ static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
}
ret = write_object(fd, (char *)&s->inode, vid_to_vdi_oid(s->inode.vdi_id),
- s->inode.nr_copies, datalen, 0, false, s->cache_enabled);
+ s->inode.nr_copies, datalen, 0, false, s->cache_flags);
if (ret < 0) {
error_report("failed to write snapshot's inode.");
goto cleanup;
@@ -1791,7 +1801,7 @@ static int sd_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
inode = (SheepdogInode *)g_malloc(datalen);
ret = read_object(fd, (char *)inode, vid_to_vdi_oid(new_vid),
- s->inode.nr_copies, datalen, 0, s->cache_enabled);
+ s->inode.nr_copies, datalen, 0, s->cache_flags);
if (ret < 0) {
error_report("failed to read new inode info. %s", strerror(errno));
@@ -1845,7 +1855,7 @@ static int sd_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
buf = g_malloc(SD_INODE_SIZE);
ret = read_object(fd, buf, vid_to_vdi_oid(vid), s->inode.nr_copies,
- SD_INODE_SIZE, 0, s->cache_enabled);
+ SD_INODE_SIZE, 0, s->cache_flags);
closesocket(fd);
@@ -1942,7 +1952,7 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
/* we don't need to read entire object */
ret = read_object(fd, (char *)&inode, vid_to_vdi_oid(vid),
0, SD_INODE_SIZE - sizeof(inode.data_vdi_id), 0,
- s->cache_enabled);
+ s->cache_flags);
if (ret) {
continue;
@@ -2003,11 +2013,11 @@ static int do_load_save_vmstate(BDRVSheepdogState *s, uint8_t *data,
if (load) {
ret = read_object(fd, (char *)data, vmstate_oid,
s->inode.nr_copies, data_len, offset,
- s->cache_enabled);
+ s->cache_flags);
} else {
ret = write_object(fd, (char *)data, vmstate_oid,
s->inode.nr_copies, data_len, offset, create,
- s->cache_enabled);
+ s->cache_flags);
}
if (ret < 0) {
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-22 11:33:09 +0000