thebestvibedev/tromcho.net
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Implement client writeback cache

Browse Source 
- Disabled by default, enable with client_enable_writeback=true
- Even then only enabled in FIO when -direct is disabled and in QEMU when
  block device cache is enabled in settings
- Can also be enabled in other clients like vitastor-cli using parameter
  client_writeback_allowed=true, but not recommended
This commit is contained in:
Vitaliy Filippov
2023-09-16 17:52:17 +03:00
parent cd543a90bc
commit 38db53f5ee
14 changed files with 999 additions and 360 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/qemu_driver.c
+88 -17
View File
@@ -388,6 +388,43 @@ static void vitastor_aio_set_fd_handler(void *vcli, int fd, int unused1, IOHandl
);
}
typedef struct str_array
{
const char **items;
int len, alloc;
} str_array;
static void strarray_push(str_array *a, const char *str)
{
if (a->len >= a->alloc)
{
a->alloc = !a->alloc ? 4 : 2*a->alloc;
a->items = (const char**)realloc(a->items, a->alloc*sizeof(char*));
if (!a->items)
{
fprintf(stderr, "bad alloc\n");
abort();
}
}
a->items[a->len++] = str;
}
static void strarray_push_kv(str_array *a, const char *key, const char *value)
{
if (key && value)
{
strarray_push(a, key);
strarray_push(a, value);
}
}
static void strarray_free(str_array *a)
{
free(a->items);
a->items = NULL;
a->len = a->alloc = 0;
}
static int vitastor_file_open(BlockDriverState *bs, QDict *options, int flags, Error **errp)
{
VitastorRPC task;
@@ -406,23 +443,19 @@ static int vitastor_file_open(BlockDriverState *bs, QDict *options, int flags, E
client->rdma_gid_index = qdict_get_try_int(options, "rdma-gid-index", 0);
client->rdma_mtu = qdict_get_try_int(options, "rdma-mtu", 0);
client->ctx = bdrv_get_aio_context(bs);
#if defined VITASTOR_C_API_VERSION && VITASTOR_C_API_VERSION >= 2
client->proxy = vitastor_c_create_qemu_uring(
vitastor_aio_set_fd_handler, client, client->config_path, client->etcd_host, client->etcd_prefix,
client->use_rdma, client->rdma_device, client->rdma_port_num, client->rdma_gid_index, client->rdma_mtu, 0
);
if (!client->proxy)
{
fprintf(stderr, "vitastor: failed to create io_uring: %s - I/O will be slower\n", strerror(errno));
client->uring_eventfd = -1;
#endif
client->proxy = vitastor_c_create_qemu(
vitastor_aio_set_fd_handler, client, client->config_path, client->etcd_host, client->etcd_prefix,
client->use_rdma, client->rdma_device, client->rdma_port_num, client->rdma_gid_index, client->rdma_mtu, 0
);
#if defined VITASTOR_C_API_VERSION && VITASTOR_C_API_VERSION >= 2
}
else
str_array opt = {};
strarray_push_kv(&opt, "config_path", qdict_get_try_str(options, "config-path"));
strarray_push_kv(&opt, "etcd_address", qdict_get_try_str(options, "etcd-host"));
strarray_push_kv(&opt, "etcd_prefix", qdict_get_try_str(options, "etcd-prefix"));
strarray_push_kv(&opt, "use_rdma", qdict_get_try_str(options, "use-rdma"));
strarray_push_kv(&opt, "rdma_device", qdict_get_try_str(options, "rdma-device"));
strarray_push_kv(&opt, "rdma_port_num", qdict_get_try_str(options, "rdma-port-num"));
strarray_push_kv(&opt, "rdma_gid_index", qdict_get_try_str(options, "rdma-gid-index"));
strarray_push_kv(&opt, "rdma_mtu", qdict_get_try_str(options, "rdma-mtu"));
strarray_push_kv(&opt, "client_writeback_allowed", (flags & BDRV_O_NOCACHE) ? "0" : "1");
client->proxy = vitastor_c_create_uring_json(opt.items, opt.len);
strarray_free(&opt);
if (client->proxy)
{
client->uring_eventfd = vitastor_c_uring_register_eventfd(client->proxy);
if (client->uring_eventfd < 0)
@@ -434,7 +467,45 @@ static int vitastor_file_open(BlockDriverState *bs, QDict *options, int flags, E
}
universal_aio_set_fd_handler(client->ctx, client->uring_eventfd, vitastor_uring_handler, NULL, client);
}
else
{
// Writeback cache is unusable without io_uring because the client can't correctly flush on exit
fprintf(stderr, "vitastor: failed to create io_uring: %s - I/O will be slower%s\n",
strerror(errno), (flags & BDRV_O_NOCACHE ? "" : " and writeback cache will be disabled"));
client->uring_eventfd = -1;
#if defined VITASTOR_C_API_VERSION && VITASTOR_C_API_VERSION >= 2
client->proxy = vitastor_c_create_qemu_uring(
vitastor_aio_set_fd_handler, client, client->config_path, client->etcd_host, client->etcd_prefix,
client->use_rdma, client->rdma_device, client->rdma_port_num, client->rdma_gid_index, client->rdma_mtu, 0
);
if (!client->proxy)
{
fprintf(stderr, "vitastor: failed to create io_uring: %s - I/O will be slower\n", strerror(errno));
client->uring_eventfd = -1;
client->proxy = vitastor_c_create_qemu(
vitastor_aio_set_fd_handler, client, client->config_path, client->etcd_host, client->etcd_prefix,
client->use_rdma, client->rdma_device, client->rdma_port_num, client->rdma_gid_index, client->rdma_mtu, 0
);
}
else
{
client->uring_eventfd = vitastor_c_uring_register_eventfd(client->proxy);
if (client->uring_eventfd < 0)
{
fprintf(stderr, "vitastor: failed to create io_uring eventfd: %s\n", strerror(errno));
error_setg(errp, "failed to create io_uring eventfd");
vitastor_close(bs);
return -1;
}
universal_aio_set_fd_handler(client->ctx, client->uring_eventfd, vitastor_uring_handler, NULL, client);
}
#else
client->proxy = vitastor_c_create_qemu(
vitastor_aio_set_fd_handler, client, client->config_path, client->etcd_host, client->etcd_prefix,
client->use_rdma, client->rdma_device, client->rdma_port_num, client->rdma_gid_index, client->rdma_mtu, 0
);
#endif
}
image = client->image = g_strdup(qdict_get_try_str(options, "image"));
client->readonly = (flags & BDRV_O_RDWR) ? 1 : 0;
// Get image metadata (size and readonly flag) or just wait until the client is ready