#include "trace.h"
#include "nbd-internal.h"
+#define NBD_META_ID_BASE_ALLOCATION 0
+#define NBD_META_ID_DIRTY_BITMAP 1
+
+/* NBD_MAX_BITMAP_EXTENTS: 1 mb of extents data. An empirical
+ * constant. If an increase is needed, note that the NBD protocol
+ * recommends no larger than 32 mb, so that the client won't consider
+ * the reply as a denial of service attack. */
+#define NBD_MAX_BITMAP_EXTENTS (0x100000 / 8)
+
static int system_errno_to_nbd_errno(int err)
{
switch (err) {
BlockBackend *blk;
char *name;
char *description;
- off_t dev_offset;
- off_t size;
+ uint64_t dev_offset;
+ uint64_t size;
uint16_t nbdflags;
QTAILQ_HEAD(, NBDClient) clients;
QTAILQ_ENTRY(NBDExport) next;
BlockBackend *eject_notifier_blk;
Notifier eject_notifier;
+
+ BdrvDirtyBitmap *export_bitmap;
+ char *export_bitmap_context;
};
static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
+/* NBDExportMetaContexts represents a list of contexts to be exported,
+ * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
+ * NBD_OPT_LIST_META_CONTEXT. */
+typedef struct NBDExportMetaContexts {
+ NBDExport *exp;
+ bool valid; /* means that negotiation of the option finished without
+ errors */
+ bool base_allocation; /* export base:allocation context (block status) */
+ bool bitmap; /* export qemu:dirty-bitmap:<export bitmap name> */
+} NBDExportMetaContexts;
+
struct NBDClient {
int refcount;
void (*close_fn)(NBDClient *client, bool negotiated);
bool closing;
bool structured_reply;
+ NBDExportMetaContexts export_meta;
uint32_t opt; /* Current option being negotiated */
uint32_t optlen; /* remaining length of data in ioc for the option being
return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO : 1;
}
+/* Drop size bytes from the unparsed payload of the current option.
+ * 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_opt_skip(NBDClient *client, size_t size, Error **errp)
+{
+ if (size > client->optlen) {
+ return nbd_opt_invalid(client, errp,
+ "Inconsistent lengths in option %s",
+ nbd_opt_lookup(client->opt));
+ }
+ client->optlen -= size;
+ return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1;
+}
+
+/* nbd_opt_read_name
+ *
+ * Read a string with the format:
+ * uint32_t len (<= NBD_MAX_NAME_SIZE)
+ * len bytes string (not 0-terminated)
+ *
+ * @name should be enough to store NBD_MAX_NAME_SIZE+1.
+ * If @length is non-null, it will be set to the actual string length.
+ *
+ * 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_opt_read_name(NBDClient *client, char *name, uint32_t *length,
+ Error **errp)
+{
+ int ret;
+ uint32_t len;
+
+ ret = nbd_opt_read(client, &len, sizeof(len), errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ len = cpu_to_be32(len);
+
+ if (len > NBD_MAX_NAME_SIZE) {
+ return nbd_opt_invalid(client, errp,
+ "Invalid name length: %" PRIu32, len);
+ }
+
+ ret = nbd_opt_read(client, name, len, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ name[len] = '\0';
+
+ if (length) {
+ *length = len;
+ }
+
+ return 1;
+}
+
/* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
* Return -errno on error, 0 on success. */
static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
}
+static void nbd_check_meta_export(NBDClient *client)
+{
+ client->export_meta.valid &= client->exp == client->export_meta.exp;
+}
+
/* Send a reply to NBD_OPT_EXPORT_NAME.
* Return -errno on error, 0 on success. */
static int nbd_negotiate_handle_export_name(NBDClient *client,
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
nbd_export_get(client->exp);
+ nbd_check_meta_export(client);
return 0;
}
if (rc < 0) {
return rc;
}
- cpu_to_be16s(&info);
+ info = cpu_to_be16(info);
if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) {
return -EIO;
}
2 bytes: N, number of requests (can be 0)
N * 2 bytes: N requests
*/
- rc = nbd_opt_read(client, &namelen, sizeof(namelen), errp);
- if (rc <= 0) {
- return rc;
- }
- be32_to_cpus(&namelen);
- if (namelen >= sizeof(name)) {
- return nbd_opt_invalid(client, errp, "name too long for qemu");
- }
- rc = nbd_opt_read(client, name, namelen, errp);
+ rc = nbd_opt_read_name(client, name, &namelen, errp);
if (rc <= 0) {
return rc;
}
- name[namelen] = '\0';
trace_nbd_negotiate_handle_export_name_request(name);
rc = nbd_opt_read(client, &requests, sizeof(requests), errp);
if (rc <= 0) {
return rc;
}
- be16_to_cpus(&requests);
+ requests = be16_to_cpu(requests);
trace_nbd_negotiate_handle_info_requests(requests);
while (requests--) {
rc = nbd_opt_read(client, &request, sizeof(request), errp);
if (rc <= 0) {
return rc;
}
- be16_to_cpus(&request);
+ request = be16_to_cpu(request);
trace_nbd_negotiate_handle_info_request(request,
nbd_info_lookup(request));
/* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
/* maximum - At most 32M, but smaller as appropriate. */
sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE);
trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
- cpu_to_be32s(&sizes[0]);
- cpu_to_be32s(&sizes[1]);
- cpu_to_be32s(&sizes[2]);
+ sizes[0] = cpu_to_be32(sizes[0]);
+ sizes[1] = cpu_to_be32(sizes[1]);
+ sizes[2] = cpu_to_be32(sizes[2]);
rc = nbd_negotiate_send_info(client, NBD_INFO_BLOCK_SIZE,
sizeof(sizes), sizes, errp);
if (rc < 0) {
client->exp = exp;
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
nbd_export_get(client->exp);
+ nbd_check_meta_export(client);
rc = 1;
}
return rc;
return QIO_CHANNEL(tioc);
}
+/* nbd_negotiate_send_meta_context
+ *
+ * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
+ *
+ * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
+ */
+static int nbd_negotiate_send_meta_context(NBDClient *client,
+ const char *context,
+ uint32_t context_id,
+ Error **errp)
+{
+ NBDOptionReplyMetaContext opt;
+ struct iovec iov[] = {
+ {.iov_base = &opt, .iov_len = sizeof(opt)},
+ {.iov_base = (void *)context, .iov_len = strlen(context)}
+ };
+
+ if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
+ context_id = 0;
+ }
+
+ trace_nbd_negotiate_meta_query_reply(context, context_id);
+ set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT,
+ sizeof(opt) - sizeof(opt.h) + iov[1].iov_len);
+ stl_be_p(&opt.context_id, context_id);
+
+ return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : 0;
+}
+
+/* Read strlen(@pattern) bytes, and set @match to true if they match @pattern.
+ * @match is never set to false.
+ *
+ * Return -errno on I/O error, 0 if option was completely handled by
+ * sending a reply about inconsistent lengths, or 1 on success.
+ *
+ * Note: return code = 1 doesn't mean that we've read exactly @pattern.
+ * It only means that there are no errors.
+ */
+static int nbd_meta_pattern(NBDClient *client, const char *pattern, bool *match,
+ Error **errp)
+{
+ int ret;
+ char *query;
+ size_t len = strlen(pattern);
+
+ assert(len);
+
+ query = g_malloc(len);
+ ret = nbd_opt_read(client, query, len, errp);
+ if (ret <= 0) {
+ g_free(query);
+ return ret;
+ }
+
+ if (strncmp(query, pattern, len) == 0) {
+ trace_nbd_negotiate_meta_query_parse(pattern);
+ *match = true;
+ } else {
+ trace_nbd_negotiate_meta_query_skip("pattern not matched");
+ }
+ g_free(query);
+
+ return 1;
+}
+
+/*
+ * Read @len bytes, and set @match to true if they match @pattern, or if @len
+ * is 0 and the client is performing _LIST_. @match is never set to false.
+ *
+ * Return -errno on I/O error, 0 if option was completely handled by
+ * sending a reply about inconsistent lengths, or 1 on success.
+ *
+ * Note: return code = 1 doesn't mean that we've read exactly @pattern.
+ * It only means that there are no errors.
+ */
+static int nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern,
+ uint32_t len, bool *match, Error **errp)
+{
+ if (len == 0) {
+ if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
+ *match = true;
+ }
+ trace_nbd_negotiate_meta_query_parse("empty");
+ return 1;
+ }
+
+ if (len != strlen(pattern)) {
+ trace_nbd_negotiate_meta_query_skip("different lengths");
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ return nbd_meta_pattern(client, pattern, match, errp);
+}
+
+/* nbd_meta_base_query
+ *
+ * Handle queries to 'base' namespace. For now, only the base:allocation
+ * context is available. 'len' is the amount of text remaining to be read from
+ * the current name, after the 'base:' 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_base_query(NBDClient *client, NBDExportMetaContexts *meta,
+ uint32_t len, Error **errp)
+{
+ return nbd_meta_empty_or_pattern(client, "allocation", len,
+ &meta->base_allocation, errp);
+}
+
+/* nbd_meta_bitmap_query
+ *
+ * Handle query to 'qemu:' namespace.
+ * @len is the amount of text remaining to be read from the current name, after
+ * the 'qemu:' 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_qemu_query(NBDClient *client, NBDExportMetaContexts *meta,
+ uint32_t len, Error **errp)
+{
+ bool dirty_bitmap = false;
+ size_t dirty_bitmap_len = strlen("dirty-bitmap:");
+ int ret;
+
+ if (!meta->exp->export_bitmap) {
+ trace_nbd_negotiate_meta_query_skip("no dirty-bitmap exported");
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ if (len == 0) {
+ if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
+ meta->bitmap = true;
+ }
+ trace_nbd_negotiate_meta_query_parse("empty");
+ return 1;
+ }
+
+ if (len < dirty_bitmap_len) {
+ trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ len -= dirty_bitmap_len;
+ ret = nbd_meta_pattern(client, "dirty-bitmap:", &dirty_bitmap, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ if (!dirty_bitmap) {
+ trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
+
+ return nbd_meta_empty_or_pattern(
+ client, meta->exp->export_bitmap_context +
+ strlen("qemu:dirty_bitmap:"), len, &meta->bitmap, errp);
+}
+
+/* nbd_negotiate_meta_query
+ *
+ * Parse namespace name and call corresponding function to parse body of the
+ * query.
+ *
+ * The only supported namespace now is 'base'.
+ *
+ * The function aims not wasting time and memory to read long unknown namespace
+ * names.
+ *
+ * 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_negotiate_meta_query(NBDClient *client,
+ NBDExportMetaContexts *meta, Error **errp)
+{
+ /*
+ * Both 'qemu' and 'base' namespaces have length = 5 including a
+ * colon. If another length namespace is later introduced, this
+ * should certainly be refactored.
+ */
+ int ret;
+ size_t ns_len = 5;
+ char ns[5];
+ uint32_t len;
+
+ ret = nbd_opt_read(client, &len, sizeof(len), errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ len = cpu_to_be32(len);
+
+ if (len < ns_len) {
+ trace_nbd_negotiate_meta_query_skip("length too short");
+ return nbd_opt_skip(client, len, errp);
+ }
+
+ len -= ns_len;
+ ret = nbd_opt_read(client, ns, ns_len, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ if (!strncmp(ns, "base:", ns_len)) {
+ trace_nbd_negotiate_meta_query_parse("base:");
+ return nbd_meta_base_query(client, meta, len, errp);
+ } else if (!strncmp(ns, "qemu:", ns_len)) {
+ trace_nbd_negotiate_meta_query_parse("qemu:");
+ return nbd_meta_qemu_query(client, meta, len, errp);
+ }
+
+ trace_nbd_negotiate_meta_query_skip("unknown namespace");
+ return nbd_opt_skip(client, len, errp);
+}
+
+/* nbd_negotiate_meta_queries
+ * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
+ *
+ * Return -errno on I/O error, or 0 if option was completely handled. */
+static int nbd_negotiate_meta_queries(NBDClient *client,
+ NBDExportMetaContexts *meta, Error **errp)
+{
+ int ret;
+ char export_name[NBD_MAX_NAME_SIZE + 1];
+ NBDExportMetaContexts local_meta;
+ uint32_t nb_queries;
+ int i;
+
+ if (!client->structured_reply) {
+ return nbd_opt_invalid(client, errp,
+ "request option '%s' when structured reply "
+ "is not negotiated",
+ nbd_opt_lookup(client->opt));
+ }
+
+ if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
+ /* Only change the caller's meta on SET. */
+ meta = &local_meta;
+ }
+
+ memset(meta, 0, sizeof(*meta));
+
+ ret = nbd_opt_read_name(client, export_name, NULL, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ meta->exp = nbd_export_find(export_name);
+ if (meta->exp == NULL) {
+ return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
+ "export '%s' not present", export_name);
+ }
+
+ ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ nb_queries = cpu_to_be32(nb_queries);
+ trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt),
+ export_name, nb_queries);
+
+ if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
+ /* enable all known contexts */
+ meta->base_allocation = true;
+ meta->bitmap = !!meta->exp->export_bitmap;
+ } else {
+ for (i = 0; i < nb_queries; ++i) {
+ ret = nbd_negotiate_meta_query(client, meta, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ }
+ }
+
+ if (meta->base_allocation) {
+ ret = nbd_negotiate_send_meta_context(client, "base:allocation",
+ NBD_META_ID_BASE_ALLOCATION,
+ errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ if (meta->bitmap) {
+ ret = nbd_negotiate_send_meta_context(client,
+ meta->exp->export_bitmap_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;
+ }
+
+ return ret;
+}
+
/* nbd_negotiate_options
* Process all NBD_OPT_* client option commands, during fixed newstyle
* negotiation.
error_prepend(errp, "read failed: ");
return -EIO;
}
- be32_to_cpus(&flags);
+ flags = be32_to_cpu(flags);
trace_nbd_negotiate_options_flags(flags);
if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
fixedNewstyle = true;
return -EINVAL;
default:
- ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD, errp,
- "Option 0x%" PRIx32
- "not permitted before TLS", option);
/* Let the client keep trying, unless they asked to
- * quit. In this mode, we've already sent an error, so
- * we can't ack the abort. */
+ * quit. Always try to give an error back to the
+ * client; but when replying to OPT_ABORT, be aware
+ * that the client may hang up before receiving the
+ * error, in which case we are fine ignoring the
+ * resulting EPIPE. */
+ ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD,
+ option == NBD_OPT_ABORT ? NULL : errp,
+ "Option 0x%" PRIx32
+ " not permitted before TLS", option);
if (option == NBD_OPT_ABORT) {
return 1;
}
}
break;
+ case NBD_OPT_LIST_META_CONTEXT:
+ case NBD_OPT_SET_META_CONTEXT:
+ ret = nbd_negotiate_meta_queries(client, &client->export_meta,
+ errp);
+ break;
+
default:
ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp,
"Unsupported option %" PRIu32 " (%s)",
int ret;
const uint16_t myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA |
- NBD_FLAG_SEND_WRITE_ZEROES);
- bool oldStyle;
+ NBD_FLAG_SEND_WRITE_ZEROES | NBD_FLAG_SEND_CACHE);
/* Old style negotiation header, no room for options
[ 0 .. 7] passwd ("NBDMAGIC")
trace_nbd_negotiate_begin();
memcpy(buf, "NBDMAGIC", 8);
- oldStyle = client->exp != NULL && !client->tlscreds;
- if (oldStyle) {
- trace_nbd_negotiate_old_style(client->exp->size,
- client->exp->nbdflags | myflags);
- stq_be_p(buf + 8, NBD_CLIENT_MAGIC);
- stq_be_p(buf + 16, client->exp->size);
- stl_be_p(buf + 24, client->exp->nbdflags | myflags);
+ stq_be_p(buf + 8, NBD_OPTS_MAGIC);
+ stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
- if (nbd_write(client->ioc, buf, sizeof(buf), errp) < 0) {
- error_prepend(errp, "write failed: ");
- return -EINVAL;
- }
- } else {
- stq_be_p(buf + 8, NBD_OPTS_MAGIC);
- stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
-
- if (nbd_write(client->ioc, buf, 18, errp) < 0) {
- error_prepend(errp, "write failed: ");
- return -EINVAL;
- }
- ret = nbd_negotiate_options(client, myflags, errp);
- if (ret != 0) {
- if (ret < 0) {
- error_prepend(errp, "option negotiation failed: ");
- }
- return ret;
+ if (nbd_write(client->ioc, buf, 18, errp) < 0) {
+ error_prepend(errp, "write failed: ");
+ return -EINVAL;
+ }
+ ret = nbd_negotiate_options(client, myflags, errp);
+ if (ret != 0) {
+ if (ret < 0) {
+ error_prepend(errp, "option negotiation failed: ");
}
+ return ret;
}
assert(!client->optlen);
nbd_export_close(exp);
}
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
- uint16_t nbdflags, void (*close)(NBDExport *),
- bool writethrough, BlockBackend *on_eject_blk,
- Error **errp)
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+ uint64_t size, const char *name, const char *desc,
+ const char *bitmap, uint16_t nbdflags,
+ void (*close)(NBDExport *), bool writethrough,
+ BlockBackend *on_eject_blk, Error **errp)
{
AioContext *ctx;
BlockBackend *blk;
* that BDRV_O_INACTIVE is cleared and the image is ready for write
* access since the export could be available before migration handover.
*/
+ assert(name);
ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
bdrv_invalidate_cache(bs, NULL);
exp->refcount = 1;
QTAILQ_INIT(&exp->clients);
exp->blk = blk;
+ assert(dev_offset <= INT64_MAX);
exp->dev_offset = dev_offset;
+ exp->name = g_strdup(name);
+ exp->description = g_strdup(desc);
exp->nbdflags = nbdflags;
- exp->size = size < 0 ? blk_getlength(blk) : size;
- if (exp->size < 0) {
- error_setg_errno(errp, -exp->size,
- "Failed to determine the NBD export's length");
- goto fail;
+ assert(size <= INT64_MAX - dev_offset);
+ exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
+
+ if (bitmap) {
+ BdrvDirtyBitmap *bm = NULL;
+ BlockDriverState *bs = blk_bs(blk);
+
+ 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);
+ goto fail;
+ }
+
+ if ((nbdflags & NBD_FLAG_READ_ONLY) && bdrv_is_writable(bs) &&
+ bdrv_dirty_bitmap_enabled(bm)) {
+ error_setg(errp,
+ "Enabled bitmap '%s' incompatible with readonly export",
+ bitmap);
+ goto fail;
+ }
+
+ if (bdrv_dirty_bitmap_user_locked(bm)) {
+ error_setg(errp, "Bitmap '%s' is in use", bitmap);
+ goto fail;
+ }
+
+ bdrv_dirty_bitmap_set_qmp_locked(bm, true);
+ exp->export_bitmap = bm;
+ exp->export_bitmap_context = g_strdup_printf("qemu:dirty-bitmap:%s",
+ bitmap);
}
- exp->size -= exp->size % BDRV_SECTOR_SIZE;
exp->close = close;
exp->ctx = blk_get_aio_context(blk);
exp->eject_notifier.notify = nbd_eject_notifier;
blk_add_remove_bs_notifier(on_eject_blk, &exp->eject_notifier);
}
+ QTAILQ_INSERT_TAIL(&exports, exp, next);
+ nbd_export_get(exp);
return exp;
fail:
blk_unref(blk);
+ g_free(exp->name);
+ g_free(exp->description);
g_free(exp);
return NULL;
}
return NULL;
}
-void nbd_export_set_name(NBDExport *exp, const char *name)
-{
- if (exp->name == name) {
- return;
- }
-
- nbd_export_get(exp);
- if (exp->name != NULL) {
- g_free(exp->name);
- exp->name = NULL;
- QTAILQ_REMOVE(&exports, exp, next);
- nbd_export_put(exp);
- }
- if (name != NULL) {
- nbd_export_get(exp);
- exp->name = g_strdup(name);
- QTAILQ_INSERT_TAIL(&exports, exp, next);
- }
- nbd_export_put(exp);
-}
-
-void nbd_export_set_description(NBDExport *exp, const char *description)
-{
- g_free(exp->description);
- exp->description = g_strdup(description);
-}
-
void nbd_export_close(NBDExport *exp)
{
NBDClient *client, *next;
nbd_export_get(exp);
+ /*
+ * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
+ * close mode that stops advertising the export to new clients but
+ * still permits existing clients to run to completion? Because of
+ * that possibility, nbd_export_close() can be called more than
+ * once on an export.
+ */
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
client_close(client, true);
}
- nbd_export_set_name(exp, NULL);
- nbd_export_set_description(exp, NULL);
+ if (exp->name) {
+ nbd_export_put(exp);
+ g_free(exp->name);
+ exp->name = NULL;
+ QTAILQ_REMOVE(&exports, exp, next);
+ }
+ g_free(exp->description);
+ exp->description = NULL;
nbd_export_put(exp);
}
exp->blk = NULL;
}
+ if (exp->export_bitmap) {
+ bdrv_dirty_bitmap_set_qmp_locked(exp->export_bitmap, false);
+ g_free(exp->export_bitmap_context);
+ }
+
g_free(exp);
}
}
return ret;
}
+/*
+ * Populate @extents from block status. Update @bytes to be the actual
+ * length encoded (which may be smaller than the original), and update
+ * @nb_extents to the number of extents used.
+ *
+ * Returns zero on success and -errno on bdrv_block_status_above failure.
+ */
+static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
+ uint64_t *bytes, NBDExtent *extents,
+ unsigned int *nb_extents)
+{
+ uint64_t remaining_bytes = *bytes;
+ NBDExtent *extent = extents, *extents_end = extents + *nb_extents;
+ bool first_extent = true;
+
+ assert(*nb_extents);
+ while (remaining_bytes) {
+ uint32_t flags;
+ int64_t num;
+ int ret = bdrv_block_status_above(bs, NULL, offset, remaining_bytes,
+ &num, NULL, NULL);
+
+ if (ret < 0) {
+ return ret;
+ }
+
+ flags = (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) |
+ (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0);
+ offset += num;
+ remaining_bytes -= num;
+
+ if (first_extent) {
+ extent->flags = flags;
+ extent->length = num;
+ first_extent = false;
+ continue;
+ }
+
+ if (flags == extent->flags) {
+ /* extend current extent */
+ extent->length += num;
+ } else {
+ if (extent + 1 == extents_end) {
+ break;
+ }
+
+ /* start new extent */
+ extent++;
+ extent->flags = flags;
+ extent->length = num;
+ }
+ }
+
+ extents_end = extent + 1;
+
+ for (extent = extents; extent < extents_end; extent++) {
+ extent->flags = cpu_to_be32(extent->flags);
+ extent->length = cpu_to_be32(extent->length);
+ }
+
+ *bytes -= remaining_bytes;
+ *nb_extents = extents_end - extents;
+
+ return 0;
+}
+
+/* nbd_co_send_extents
+ *
+ * @length is only for tracing purposes (and may be smaller or larger
+ * than the client's original request). @last controls whether
+ * NBD_REPLY_FLAG_DONE is sent. @extents should already be in
+ * big-endian format.
+ */
+static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
+ NBDExtent *extents, unsigned int nb_extents,
+ uint64_t length, bool last,
+ uint32_t context_id, Error **errp)
+{
+ NBDStructuredMeta chunk;
+
+ struct iovec iov[] = {
+ {.iov_base = &chunk, .iov_len = sizeof(chunk)},
+ {.iov_base = extents, .iov_len = nb_extents * sizeof(extents[0])}
+ };
+
+ trace_nbd_co_send_extents(handle, nb_extents, context_id, length, last);
+ set_be_chunk(&chunk.h, last ? NBD_REPLY_FLAG_DONE : 0,
+ NBD_REPLY_TYPE_BLOCK_STATUS,
+ handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
+ stl_be_p(&chunk.context_id, context_id);
+
+ return nbd_co_send_iov(client, iov, 2, errp);
+}
+
+/* Get block status from the exported device and send it to the client */
+static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
+ BlockDriverState *bs, uint64_t offset,
+ uint32_t length, bool dont_fragment,
+ bool last, uint32_t context_id,
+ Error **errp)
+{
+ int ret;
+ unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
+ NBDExtent *extents = g_new(NBDExtent, nb_extents);
+ uint64_t final_length = length;
+
+ ret = blockstatus_to_extents(bs, offset, &final_length, extents,
+ &nb_extents);
+ if (ret < 0) {
+ g_free(extents);
+ return nbd_co_send_structured_error(
+ client, handle, -ret, "can't get block status", errp);
+ }
+
+ ret = nbd_co_send_extents(client, handle, extents, nb_extents,
+ final_length, last, context_id, errp);
+
+ g_free(extents);
+
+ return ret;
+}
+
+/*
+ * Populate @extents from a dirty bitmap. Unless @dont_fragment, the
+ * final extent may exceed the original @length. Store in @length the
+ * byte length encoded (which may be smaller or larger than the
+ * original), and return the number of extents used.
+ */
+static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
+ uint64_t *length, NBDExtent *extents,
+ unsigned int nb_extents,
+ bool dont_fragment)
+{
+ uint64_t begin = offset, end = offset;
+ uint64_t overall_end = offset + *length;
+ unsigned int 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);
+
+ assert(begin < overall_end && nb_extents);
+ while (begin < overall_end && i < nb_extents) {
+ bool next_dirty = !dirty;
+
+ if (dirty) {
+ end = bdrv_dirty_bitmap_next_zero(bitmap, begin, UINT64_MAX);
+ } else {
+ bdrv_set_dirty_iter(it, begin);
+ end = bdrv_dirty_iter_next(it);
+ }
+ if (end == -1 || end - begin > UINT32_MAX) {
+ /* Cap to an aligned value < 4G beyond begin. */
+ end = MIN(bdrv_dirty_bitmap_size(bitmap),
+ begin + UINT32_MAX + 1 -
+ bdrv_dirty_bitmap_granularity(bitmap));
+ next_dirty = dirty;
+ }
+ if (dont_fragment && end > overall_end) {
+ end = overall_end;
+ }
+
+ extents[i].length = cpu_to_be32(end - begin);
+ extents[i].flags = cpu_to_be32(dirty ? NBD_STATE_DIRTY : 0);
+ i++;
+ begin = end;
+ dirty = next_dirty;
+ }
+
+ bdrv_dirty_iter_free(it);
+
+ bdrv_dirty_bitmap_unlock(bitmap);
+
+ assert(offset < end);
+ *length = end - offset;
+ return i;
+}
+
+static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
+ BdrvDirtyBitmap *bitmap, uint64_t offset,
+ uint32_t length, bool dont_fragment, bool last,
+ uint32_t context_id, Error **errp)
+{
+ int ret;
+ unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
+ NBDExtent *extents = g_new(NBDExtent, nb_extents);
+ uint64_t final_length = length;
+
+ nb_extents = bitmap_to_extents(bitmap, offset, &final_length, extents,
+ nb_extents, dont_fragment);
+
+ ret = nbd_co_send_extents(client, handle, extents, nb_extents,
+ final_length, last, 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
return -EIO;
}
- if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE) {
+ if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE ||
+ request->type == NBD_CMD_CACHE)
+ {
if (request->len > NBD_MAX_BUFFER_SIZE) {
error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)",
request->len, NBD_MAX_BUFFER_SIZE);
return -EROFS;
}
if (request->from > client->exp->size ||
- request->from + request->len > client->exp->size) {
+ request->len > client->exp->size - request->from) {
error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
", Size: %" PRIu64, request->from, request->len,
- (uint64_t)client->exp->size);
+ client->exp->size);
return (request->type == NBD_CMD_WRITE ||
request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
}
valid_flags |= NBD_CMD_FLAG_DF;
} else if (request->type == NBD_CMD_WRITE_ZEROES) {
valid_flags |= NBD_CMD_FLAG_NO_HOLE;
+ } else if (request->type == NBD_CMD_BLOCK_STATUS) {
+ valid_flags |= NBD_CMD_FLAG_REQ_ONE;
}
if (request->flags & ~valid_flags) {
error_setg(errp, "unsupported flags for command %s (got 0x%x)",
int ret;
NBDExport *exp = client->exp;
- assert(request->type == NBD_CMD_READ);
+ assert(request->type == NBD_CMD_READ || request->type == NBD_CMD_CACHE);
/* XXX: NBD Protocol only documents use of FUA with WRITE */
if (request->flags & NBD_CMD_FLAG_FUA) {
}
if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) &&
- request->len) {
+ request->len && request->type != NBD_CMD_CACHE)
+ {
return nbd_co_send_sparse_read(client, request->handle, request->from,
data, request->len, errp);
}
ret = blk_pread(exp->blk, request->from + exp->dev_offset, data,
request->len);
- if (ret < 0) {
+ if (ret < 0 || request->type == NBD_CMD_CACHE) {
return nbd_send_generic_reply(client, request->handle, ret,
"reading from file failed", errp);
}
switch (request->type) {
case NBD_CMD_READ:
+ case NBD_CMD_CACHE:
return nbd_do_cmd_read(client, request, data, errp);
case NBD_CMD_WRITE:
return nbd_send_generic_reply(client, request->handle, ret,
"discard failed", errp);
+ case NBD_CMD_BLOCK_STATUS:
+ if (!request->len) {
+ return nbd_send_generic_reply(client, request->handle, -EINVAL,
+ "need non-zero length", errp);
+ }
+ if (client->export_meta.valid &&
+ (client->export_meta.base_allocation ||
+ client->export_meta.bitmap))
+ {
+ bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE;
+
+ if (client->export_meta.base_allocation) {
+ ret = nbd_co_send_block_status(client, request->handle,
+ blk_bs(exp->blk), request->from,
+ request->len, dont_fragment,
+ !client->export_meta.bitmap,
+ NBD_META_ID_BASE_ALLOCATION,
+ errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ if (client->export_meta.bitmap) {
+ ret = nbd_co_send_bitmap(client, request->handle,
+ client->exp->export_bitmap,
+ request->from, request->len,
+ dont_fragment,
+ true, NBD_META_ID_DIRTY_BITMAP, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return ret;
+ } else {
+ return nbd_send_generic_reply(client, request->handle, -EINVAL,
+ "CMD_BLOCK_STATUS not negotiated",
+ errp);
+ }
+
default:
msg = g_strdup_printf("invalid request type (%" PRIu32 ") received",
request->type);
static coroutine_fn void nbd_co_client_start(void *opaque)
{
NBDClient *client = opaque;
- NBDExport *exp = client->exp;
Error *local_err = NULL;
- if (exp) {
- nbd_export_get(exp);
- QTAILQ_INSERT_TAIL(&exp->clients, client, next);
- }
qemu_co_mutex_init(&client->send_lock);
if (nbd_negotiate(client, &local_err)) {
}
/*
- * Create a new client listener on the given export @exp, using the
- * given channel @sioc. Begin servicing it in a coroutine. When the
- * connection closes, call @close_fn with an indication of whether the
- * client completed negotiation.
+ * Create a new client listener using the given channel @sioc.
+ * Begin servicing it in a coroutine. When the connection closes, call
+ * @close_fn with an indication of whether the client completed negotiation.
*/
-void nbd_client_new(NBDExport *exp,
- QIOChannelSocket *sioc,
+void nbd_client_new(QIOChannelSocket *sioc,
QCryptoTLSCreds *tlscreds,
const char *tlsaclname,
void (*close_fn)(NBDClient *, bool))
client = g_new0(NBDClient, 1);
client->refcount = 1;
- client->exp = exp;
client->tlscreds = tlscreds;
if (tlscreds) {
object_ref(OBJECT(client->tlscreds));
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