Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
include/block/nbd.h | 2 +
nbd/server.c | 207 ++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 203 insertions(+), 6 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index fcdcd54502..f0b459283f 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -315,6 +315,8 @@ void nbd_client_put(NBDClient *client);
void nbd_server_start(SocketAddress *addr, const char *tls_creds,
Error **errp);
+void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
+ const char *bitmap_export_name, Error **errp);
/* nbd_read
* Reads @size bytes from @ioc. Returns 0 on success.
diff --git a/nbd/server.c b/nbd/server.c
index 8fe53ffd4b..6554919ef2 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -23,6 +23,12 @@
#include "nbd-internal.h"
#define NBD_META_ID_BASE_ALLOCATION 0
+#define NBD_META_ID_DIRTY_BITMAP 1
+
+#define NBD_MAX_BITMAP_EXTENTS (0x100000 / 8) /* 1 mb of extents data */
+#define MAX_EXTENT_LENGTH QEMU_ALIGN_DOWN(INT32_MAX, 512)
+
+#define NBD_STATE_DIRTY 1
static int system_errno_to_nbd_errno(int err)
{
@@ -80,6 +86,9 @@ struct NBDExport {
BlockBackend *eject_notifier_blk;
Notifier eject_notifier;
+
+ BdrvDirtyBitmap *export_bitmap;
+ char *export_bitmap_name;
};
static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
@@ -92,6 +101,7 @@ typedef struct NBDExportMetaContexts {
bool valid; /* means that negotiation of the option finished without
errors */
bool base_allocation; /* export base:allocation context (block status) */
+ bool dirty_bitmap; /* export qemu-dirty-bitmap:<export_bitmap_name> */
} NBDExportMetaContexts;
struct NBDClient {
@@ -786,12 +796,32 @@ static int nbd_meta_base_query(NBDClient *client,
NBDExportMetaContexts *meta,
&meta->base_allocation, errp);
}
+/* nbd_meta_bitmap_query
+ *
+ * Handle query to 'qemu-dirty-bitmap' namespace.
+ * 'len' is the amount of text remaining to be read from the current name,
after
+ * the 'qemu-dirty-bitmap:' portion has been stripped.
+ *
+ * Return -errno on I/O error, 0 if option was completely handled by
+ * sending a reply about inconsistent lengths, or 1 on success. */
+static int nbd_meta_bitmap_query(NBDClient *client, NBDExportMetaContexts
*meta,
+ uint32_t len, Error **errp)
+{
+ if (!client->exp->export_bitmap) {
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ return nbd_meta_single_query(client, client->exp->export_bitmap_name, len,
+ &meta->dirty_bitmap, errp);
+}
+
struct {
const char *ns;
int (*func)(NBDClient *, NBDExportMetaContexts *, uint32_t, Error **);
} meta_namespace_handlers[] = {
/* namespaces should go in non-decreasing order by name length */
{.ns = "base:", .func = nbd_meta_base_query},
+ {.ns = "qemu-dirty-bitmap:", .func = nbd_meta_bitmap_query},
};
/* nbd_negotiate_meta_query
@@ -921,6 +951,17 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
}
}
+ if (meta->dirty_bitmap) {
+ char *context = g_strdup_printf("qemu-dirty-bitmap:%s",
+ exp->export_bitmap_name);
+ ret = nbd_negotiate_send_meta_context(client, context,
+ NBD_META_ID_DIRTY_BITMAP,
+ errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
if (ret == 0) {
meta->valid = true;
@@ -1549,6 +1590,11 @@ void nbd_export_put(NBDExport *exp)
exp->blk = NULL;
}
+ if (exp->export_bitmap) {
+ bdrv_dirty_bitmap_set_qmp_locked(exp->export_bitmap, false);
+ g_free(exp->export_bitmap_name);
+ }
+
g_free(exp);
}
}
@@ -1790,6 +1836,9 @@ static int blockstatus_to_extent_be(BlockDriverState *bs,
uint64_t offset,
}
/* nbd_co_send_extents
+ *
+ * NBD_REPLY_FLAG_DONE is not set, don't forget to send it.
+ *
* @extents should be in big-endian */
static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
NBDExtent *extents, unsigned nb_extents,
@@ -1802,7 +1851,7 @@ static int nbd_co_send_extents(NBDClient *client,
uint64_t handle,
{.iov_base = extents, .iov_len = nb_extents * sizeof(extents[0])}
};
- set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_BLOCK_STATUS,
+ set_be_chunk(&chunk.h, 0, NBD_REPLY_TYPE_BLOCK_STATUS,
handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
stl_be_p(&chunk.context_id, context_id);
@@ -1827,6 +1876,91 @@ static int nbd_co_send_block_status(NBDClient *client,
uint64_t handle,
return nbd_co_send_extents(client, handle, &extent, 1, context_id, errp);
}
+/* Set several extents, describing region of given @length with given @flags.
+ * Do not set more than @nb_extents, return number of set extents.
+ */
+static unsigned add_extents(NBDExtent *extents, unsigned nb_extents,
+ uint64_t length, uint32_t flags)
+{
+ unsigned i = 0;
+ uint32_t max_extent_be = cpu_to_be32(MAX_EXTENT_LENGTH);
+ uint32_t flags_be = cpu_to_be32(flags);
+
+ for (i = 0; i < nb_extents && length > MAX_EXTENT_LENGTH;
+ i++, length -= MAX_EXTENT_LENGTH)
+ {
+ extents[i].length = max_extent_be;
+ extents[i].flags = flags_be;
+ }
+
+ if (length > 0 && i < nb_extents) {
+ extents[i].length = cpu_to_be32(length);
+ extents[i].flags = flags_be;
+ i++;
+ }
+
+ return i;
+}
+
+static unsigned bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
+ uint64_t length, NBDExtent *extents,
+ unsigned nb_extents)
+{
+ uint64_t begin = offset, end;
+ uint64_t overall_end = offset + length;
+ unsigned i = 0;
+ BdrvDirtyBitmapIter *it;
+ bool dirty;
+
+ bdrv_dirty_bitmap_lock(bitmap);
+
+ it = bdrv_dirty_iter_new(bitmap);
+ dirty = bdrv_get_dirty_locked(NULL, bitmap, offset);
+
+ while (begin < overall_end && i < nb_extents) {
+ if (dirty) {
+ end = bdrv_dirty_bitmap_next_zero(bitmap, begin);
+ } else {
+ bdrv_set_dirty_iter(it, begin);
+ end = bdrv_dirty_iter_next(it);
+ }
+ if (end == -1) {
+ end = overall_end;
+ }
+
+ i += add_extents(extents + i, nb_extents - i, end - begin,
+ dirty ? NBD_STATE_DIRTY : 0);
+ begin = end;
+ dirty = !dirty;
+ }
+
+ bdrv_dirty_iter_free(it);
+
+ bdrv_dirty_bitmap_unlock(bitmap);
+
+ return i;
+}
+
+static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
+ BdrvDirtyBitmap *bitmap, uint64_t offset,
+ uint64_t length, uint32_t context_id,
+ Error **errp)
+{
+ int ret;
+ unsigned nb_extents;
+ NBDExtent *extents = g_new(NBDExtent, NBD_MAX_BITMAP_EXTENTS);
+
+ nb_extents = bitmap_to_extents(bitmap, offset, length, extents,
+ NBD_MAX_BITMAP_EXTENTS);
+
+ ret = nbd_co_send_extents(client, handle, extents, nb_extents, context_id,
+ errp);
+
+ g_free(extents);
+
+ return ret;
+}
+
/* nbd_co_receive_request
* Collect a client request. Return 0 if request looks valid, -EIO to drop
* connection right away, and any other negative value to report an error to
@@ -2040,11 +2174,32 @@ static coroutine_fn int nbd_handle_request(NBDClient
*client,
"discard failed", errp);
case NBD_CMD_BLOCK_STATUS:
- if (client->export_meta.valid && client->export_meta.base_allocation) {
- return nbd_co_send_block_status(client, request->handle,
- blk_bs(exp->blk), request->from,
- request->len,
- NBD_META_ID_BASE_ALLOCATION, errp);
+ if (client->export_meta.valid &&
+ (client->export_meta.base_allocation ||
+ client->export_meta.dirty_bitmap))
+ {
+ if (client->export_meta.base_allocation) {
+ ret = nbd_co_send_block_status(client, request->handle,
+ blk_bs(exp->blk), request->from,
+ request->len,
+ NBD_META_ID_BASE_ALLOCATION,
+ errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ if (client->export_meta.dirty_bitmap) {
+ ret = nbd_co_send_bitmap(client, request->handle,
+ client->exp->export_bitmap,
+ request->from, request->len,
+ NBD_META_ID_DIRTY_BITMAP, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return nbd_co_send_structured_done(client, request->handle, errp);
} else {
return nbd_send_generic_reply(client, request->handle, -EINVAL,
"CMD_BLOCK_STATUS not negotiated",
@@ -2196,3 +2351,43 @@ void nbd_client_new(NBDExport *exp,
co = qemu_coroutine_create(nbd_co_client_start, client);
qemu_coroutine_enter(co);
}
+
+void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
+ const char *bitmap_export_name, Error **errp)
+{
+ BdrvDirtyBitmap *bm = NULL;
+ BlockDriverState *bs = blk_bs(exp->blk);
+
+ if (exp->export_bitmap) {
+ error_setg(errp, "Export bitmap is already set");
+ return;
+ }
+
+ while (true) {
+ bm = bdrv_find_dirty_bitmap(bs, bitmap);
+ if (bm != NULL || bs->backing == NULL) {
+ break;
+ }
+
+ bs = bs->backing->bs;
+ }
+
+ if (bm == NULL) {
+ error_setg(errp, "Bitmap '%s' is not found", bitmap);
+ return;
+ }
+
+ if (bdrv_dirty_bitmap_enabled(bm)) {
+ error_setg(errp, "Bitmap '%s' is enabled", bitmap);
+ return;
+ }
+
+ if (bdrv_dirty_bitmap_qmp_locked(bm)) {
+ error_setg(errp, "Bitmap '%s' is locked", bitmap);
+ return;
+ }
+
+ bdrv_dirty_bitmap_set_qmp_locked(bm, true);
+ exp->export_bitmap = bm;
+ exp->export_bitmap_name = g_strdup(bitmap_export_name);
+}
--
2.11.1
