11:08 a.m.
Add the magic numbers and new structs necessary to implement the NBD
protocol extension of extended headers providing 64-bit lengths. This
corresponds to upstream nbd commits 36abf47d and a9384e2f on the
extension-ext-header branch[1] (commit e6f3b94a for
NBD_FLAG_BLOCK_STATUS_PAYLOAD is saved for a later patch).
[1] https://github.com/NetworkBlockDevice/nbd/blob/extension-ext-header/doc/p...
Signed-off-by: Eric Blake <eblake(a)redhat.com>
Reviewed-by: Laszlo Ersek <lersek(a)redhat.com>
---
v4: tweak comment on block_status_64.count [Laszlo], rebase to earlier
struct renames (for example, nbd_block_descriptor_64 instead of
nbd_structured_reply_block_status_hdr). Seemed obvious enough that I
felt okay keeping Laszlo's R-b.
---
lib/nbd-protocol.h | 55 ++++++++++++++++++++++++++++++++++++++--------
1 file changed, 46 insertions(+), 9 deletions(-)
diff --git a/lib/nbd-protocol.h b/lib/nbd-protocol.h
index 58583d1d..b5a28ae4 100644
--- a/lib/nbd-protocol.h
+++ b/lib/nbd-protocol.h
@@ -124,6 +124,7 @@ struct nbd_fixed_new_option_reply {
#define NBD_OPT_STRUCTURED_REPLY 8
#define NBD_OPT_LIST_META_CONTEXT 9
#define NBD_OPT_SET_META_CONTEXT 10
+#define NBD_OPT_EXTENDED_HEADERS 11
#define NBD_REP_ERR(val) (0x80000000 | (val))
#define NBD_REP_IS_ERR(val) (!!((val) & 0x80000000))
@@ -141,6 +142,7 @@ struct nbd_fixed_new_option_reply {
#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR (7)
#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR (8)
#define NBD_REP_ERR_TOO_BIG NBD_REP_ERR (9)
+#define NBD_REP_ERR_EXT_HEADER_REQD NBD_REP_ERR (10)
#define NBD_INFO_EXPORT 0
#define NBD_INFO_NAME 1
@@ -182,16 +184,26 @@ struct nbd_fixed_new_option_reply_meta_context {
/* followed by a string */
} NBD_ATTRIBUTE_PACKED;
-/* Request (client -> server). */
+/* Compact request (client -> server). */
struct nbd_request {
uint32_t magic; /* NBD_REQUEST_MAGIC. */
- uint16_t flags; /* Request flags. */
- uint16_t type; /* Request type. */
+ uint16_t flags; /* Request flags: NBD_CMD_FLAG_*. */
+ uint16_t type; /* Request type: NBD_CMD_*. */
uint64_t cookie; /* Opaque handle. */
uint64_t offset; /* Request offset. */
uint32_t count; /* Request length. */
} NBD_ATTRIBUTE_PACKED;
+/* Extended request (client -> server). */
+struct nbd_request_ext {
+ uint32_t magic; /* NBD_EXTENDED_REQUEST_MAGIC. */
+ uint16_t flags; /* Request flags: NBD_CMD_FLAG_*. */
+ uint16_t type; /* Request type: NBD_CMD_*. */
+ uint64_t cookie; /* Opaque handle. */
+ uint64_t offset; /* Request offset. */
+ uint64_t count; /* Request effect or payload length. */
+} NBD_ATTRIBUTE_PACKED;
+
/* Simple reply (server -> client). */
struct nbd_simple_reply {
uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */
@@ -208,6 +220,16 @@ struct nbd_structured_reply {
uint32_t length; /* Length of following nbd_chunk_* payload. */
} NBD_ATTRIBUTE_PACKED;
+/* Extended reply (server -> client). */
+struct nbd_extended_reply {
+ uint32_t magic; /* NBD_EXTENDED_REPLY_MAGIC. */
+ uint16_t flags; /* NBD_REPLY_FLAG_* */
+ uint16_t type; /* NBD_REPLY_TYPE_* */
+ uint64_t cookie; /* Opaque handle. */
+ uint64_t offset; /* Client's offset. */
+ uint64_t length; /* Length of following nbd_chunk_* payload. */
+} NBD_ATTRIBUTE_PACKED;
+
struct nbd_chunk_offset_data {
uint64_t offset; /* offset */
/* Followed by data. */
@@ -228,6 +250,17 @@ struct nbd_block_descriptor_32 {
uint32_t status_flags; /* block type (hole etc) */
} NBD_ATTRIBUTE_PACKED;
+struct nbd_chunk_block_status_64 {
+ uint32_t context_id; /* metadata context ID */
+ uint32_t count; /* non-zero descriptor count */
+ /* followed by nbd_block_descriptor_64[count] extents */
+} NBD_ATTRIBUTE_PACKED;
+
+struct nbd_block_descriptor_64 {
+ uint64_t length; /* length of block */
+ uint64_t status_flags; /* block type (hole etc) */
+} NBD_ATTRIBUTE_PACKED;
+
struct nbd_chunk_error {
uint32_t error; /* NBD_E* error number */
uint16_t len; /* Length of human readable error. */
@@ -235,8 +268,10 @@ struct nbd_chunk_error {
} NBD_ATTRIBUTE_PACKED;
#define NBD_REQUEST_MAGIC 0x25609513
+#define NBD_EXTENDED_REQUEST_MAGIC 0x21e41c71
#define NBD_SIMPLE_REPLY_MAGIC 0x67446698
#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
+#define NBD_EXTENDED_REPLY_MAGIC 0x6e8a278c
/* Structured reply flags. */
#define NBD_REPLY_FLAG_DONE (1U << 0)
@@ -245,12 +280,13 @@ struct nbd_chunk_error {
#define NBD_REPLY_TYPE_IS_ERR(val) (!!((val) & (1U<<15)))
/* Structured reply types. */
-#define NBD_REPLY_TYPE_NONE 0
-#define NBD_REPLY_TYPE_OFFSET_DATA 1
-#define NBD_REPLY_TYPE_OFFSET_HOLE 2
-#define NBD_REPLY_TYPE_BLOCK_STATUS 5
-#define NBD_REPLY_TYPE_ERROR NBD_REPLY_TYPE_ERR (1)
-#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_TYPE_ERR (2)
+#define NBD_REPLY_TYPE_NONE 0
+#define NBD_REPLY_TYPE_OFFSET_DATA 1
+#define NBD_REPLY_TYPE_OFFSET_HOLE 2
+#define NBD_REPLY_TYPE_BLOCK_STATUS 5
+#define NBD_REPLY_TYPE_BLOCK_STATUS_EXT 6
+#define NBD_REPLY_TYPE_ERROR NBD_REPLY_TYPE_ERR (1)
+#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_TYPE_ERR (2)
/* NBD commands. */
#define NBD_CMD_READ 0
@@ -267,6 +303,7 @@ struct nbd_chunk_error {
#define NBD_CMD_FLAG_DF (1U << 2)
#define NBD_CMD_FLAG_REQ_ONE (1U << 3)
#define NBD_CMD_FLAG_FAST_ZERO (1U << 4)
+#define NBD_CMD_FLAG_PAYLOAD_LEN (1U << 5)
/* NBD error codes. */
#define NBD_SUCCESS 0
--
2.41.0