Commit 25c14678 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Eric Blake
Browse files

nbd: BLOCK_STATUS constants 

Expose the new constants and structs that will be used by both
server and client implementations of NBD_CMD_BLOCK_STATUS (the
command is currently experimental at
https://github.com/NetworkBlockDevice/nbd/blob/extension-blockstatus/doc/proto.md


but will hopefully be stabilized soon).

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1518702707-7077-4-git-send-email-vsementsov@virtuozzo.com>
[eblake: split from larger patch on server implementation]
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
parent 6bc86957

include/block/nbd.h

+31 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ struct NBDOptionReply { 
} QEMU_PACKED;

typedef struct NBDOptionReply NBDOptionReply;



typedef struct NBDOptionReplyMetaContext {

    NBDOptionReply h; /* h.type = NBD_REP_META_CONTEXT, h.length > 4 */

    uint32_t context_id;

    /* meta context name follows */

} QEMU_PACKED NBDOptionReplyMetaContext;



/* Transmission phase structs

 *

 * Note: these are _NOT_ the same as the network representation of an NBD
@@ -105,6 +111,19 @@ typedef struct NBDStructuredError { 
    uint16_t message_length;

} QEMU_PACKED NBDStructuredError;



/* Header of NBD_REPLY_TYPE_BLOCK_STATUS */

typedef struct NBDStructuredMeta {

    NBDStructuredReplyChunk h; /* h.length >= 12 (at least one extent) */

    uint32_t context_id;

    /* extents follows */

} QEMU_PACKED NBDStructuredMeta;



/* Extent chunk for NBD_REPLY_TYPE_BLOCK_STATUS */

typedef struct NBDExtent {

    uint32_t length;

    uint32_t flags; /* NBD_STATE_* */

} QEMU_PACKED NBDExtent;



/* Transmission (export) flags: sent from server to client during handshake,

   but describe what will happen during transmission */

#define NBD_FLAG_HAS_FLAGS         (1 << 0) /* Flags are there */
@@ -136,6 +155,8 @@ typedef struct NBDStructuredError { 
#define NBD_OPT_INFO              (6)

#define NBD_OPT_GO                (7)

#define NBD_OPT_STRUCTURED_REPLY  (8)

#define NBD_OPT_LIST_META_CONTEXT (9)

#define NBD_OPT_SET_META_CONTEXT  (10)



/* Option reply types. */

#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) | (value))
@@ -143,6 +164,7 @@ typedef struct NBDStructuredError { 
#define NBD_REP_ACK             (1)    /* Data sending finished. */

#define NBD_REP_SERVER          (2)    /* Export description. */

#define NBD_REP_INFO            (3)    /* NBD_OPT_INFO/GO. */

#define NBD_REP_META_CONTEXT    (4)    /* NBD_OPT_{LIST,SET}_META_CONTEXT */



#define NBD_REP_ERR_UNSUP           NBD_REP_ERR(1)  /* Unknown option */

#define NBD_REP_ERR_POLICY          NBD_REP_ERR(2)  /* Server denied */
@@ -163,6 +185,8 @@ typedef struct NBDStructuredError { 
#define NBD_CMD_FLAG_FUA        (1 << 0) /* 'force unit access' during write */

#define NBD_CMD_FLAG_NO_HOLE    (1 << 1) /* don't punch hole on zero run */

#define NBD_CMD_FLAG_DF         (1 << 2) /* don't fragment structured read */

#define NBD_CMD_FLAG_REQ_ONE    (1 << 3) /* only one extent in BLOCK_STATUS

                                          * reply chunk */



/* Supported request types */

enum {
@@ -173,6 +197,7 @@ enum { 
    NBD_CMD_TRIM = 4,

    /* 5 reserved for failed experiment NBD_CMD_CACHE */

    NBD_CMD_WRITE_ZEROES = 6,

    NBD_CMD_BLOCK_STATUS = 7,

};



#define NBD_DEFAULT_PORT	10809
@@ -200,9 +225,15 @@ enum { 
#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_ERR(1)

#define NBD_REPLY_TYPE_ERROR_OFFSET  NBD_REPLY_ERR(2)



/* Flags for extents (NBDExtent.flags) of NBD_REPLY_TYPE_BLOCK_STATUS,

 * for base:allocation meta context */

#define NBD_STATE_HOLE (1 << 0)

#define NBD_STATE_ZERO (1 << 1)



static inline bool nbd_reply_type_is_error(int type)

{

    return type & (1 << 15);

nbd/common.c

+10 −0
Original line number Diff line number Diff line
@@ -75,6 +75,10 @@ const char *nbd_opt_lookup(uint32_t opt) 
        return "go";

    case NBD_OPT_STRUCTURED_REPLY:

        return "structured reply";

    case NBD_OPT_LIST_META_CONTEXT:

        return "list meta context";

    case NBD_OPT_SET_META_CONTEXT:

        return "set meta context";

    default:

        return "<unknown>";

    }
@@ -90,6 +94,8 @@ const char *nbd_rep_lookup(uint32_t rep) 
        return "server";

    case NBD_REP_INFO:

        return "info";

    case NBD_REP_META_CONTEXT:

        return "meta context";

    case NBD_REP_ERR_UNSUP:

        return "unsupported";

    case NBD_REP_ERR_POLICY:
@@ -144,6 +150,8 @@ const char *nbd_cmd_lookup(uint16_t cmd) 
        return "trim";

    case NBD_CMD_WRITE_ZEROES:

        return "write zeroes";

    case NBD_CMD_BLOCK_STATUS:

        return "block status";

    default:

        return "<unknown>";

    }
@@ -159,6 +167,8 @@ const char *nbd_reply_type_lookup(uint16_t type) 
        return "data";

    case NBD_REPLY_TYPE_OFFSET_HOLE:

        return "hole";

    case NBD_REPLY_TYPE_BLOCK_STATUS:

        return "block status";

    case NBD_REPLY_TYPE_ERROR:

        return "generic error";

    case NBD_REPLY_TYPE_ERROR_OFFSET: