Commit 70c4fb26 authored by Eric Blake's avatar Eric Blake Committed by Stefan Hajnoczi
Browse files

nbd: Convert to byte-based interface 



The NBD protocol doesn't have any notion of sectors, so it is
a fairly easy conversion to use byte-based read and write.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1468624988-423-19-git-send-email-eblake@redhat.com
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 02aefe43

block/nbd-client.c

+17 −13
Original line number Diff line number Diff line
@@ -218,17 +218,20 @@ static void nbd_coroutine_end(NbdClientSession *s, 
    }

}



int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num,

                        int nb_sectors, QEMUIOVector *qiov)

int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,

                         uint64_t bytes, QEMUIOVector *qiov, int flags)

{

    NbdClientSession *client = nbd_get_client_session(bs);

    struct nbd_request request = { .type = NBD_CMD_READ };

    struct nbd_request request = {

        .type = NBD_CMD_READ,

        .from = offset,

        .len = bytes,

    };

    struct nbd_reply reply;

    ssize_t ret;



    assert(nb_sectors <= NBD_MAX_SECTORS);

    request.from = sector_num * 512;

    request.len = nb_sectors * 512;

    assert(bytes <= NBD_MAX_BUFFER_SIZE);

    assert(!flags);



    nbd_coroutine_start(client, &request);

    ret = nbd_co_send_request(bs, &request, NULL);
@@ -239,14 +242,17 @@ int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num, 
    }

    nbd_coroutine_end(client, &request);

    return -reply.error;



}



int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num,

                         int nb_sectors, QEMUIOVector *qiov, int flags)

int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,

                          uint64_t bytes, QEMUIOVector *qiov, int flags)

{

    NbdClientSession *client = nbd_get_client_session(bs);

    struct nbd_request request = { .type = NBD_CMD_WRITE };

    struct nbd_request request = {

        .type = NBD_CMD_WRITE,

        .from = offset,

        .len = bytes,

    };

    struct nbd_reply reply;

    ssize_t ret;
@@ -255,9 +261,7 @@ int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num, 
        request.type |= NBD_CMD_FLAG_FUA;

    }



    assert(nb_sectors <= NBD_MAX_SECTORS);

    request.from = sector_num * 512;

    request.len = nb_sectors * 512;

    assert(bytes <= NBD_MAX_BUFFER_SIZE);



    nbd_coroutine_start(client, &request);

    ret = nbd_co_send_request(bs, &request, qiov);

block/nbd-client.h

+4 −4
Original line number Diff line number Diff line
@@ -46,10 +46,10 @@ void nbd_client_close(BlockDriverState *bs); 


int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);

int nbd_client_co_flush(BlockDriverState *bs);

int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num,

                         int nb_sectors, QEMUIOVector *qiov, int flags);

int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num,

                        int nb_sectors, QEMUIOVector *qiov);

int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,

                          uint64_t bytes, QEMUIOVector *qiov, int flags);

int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,

                         uint64_t bytes, QEMUIOVector *qiov, int flags);



void nbd_client_detach_aio_context(BlockDriverState *bs);

void nbd_client_attach_aio_context(BlockDriverState *bs,

block/nbd.c

+6 −6
Original line number Diff line number Diff line
@@ -438,8 +438,8 @@ static BlockDriver bdrv_nbd = { 
    .instance_size              = sizeof(BDRVNBDState),

    .bdrv_parse_filename        = nbd_parse_filename,

    .bdrv_file_open             = nbd_open,

    .bdrv_co_readv              = nbd_client_co_readv,

    .bdrv_co_writev_flags       = nbd_client_co_writev,

    .bdrv_co_preadv             = nbd_client_co_preadv,

    .bdrv_co_pwritev            = nbd_client_co_pwritev,

    .bdrv_close                 = nbd_close,

    .bdrv_co_flush_to_os        = nbd_co_flush,

    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
@@ -456,8 +456,8 @@ static BlockDriver bdrv_nbd_tcp = { 
    .instance_size              = sizeof(BDRVNBDState),

    .bdrv_parse_filename        = nbd_parse_filename,

    .bdrv_file_open             = nbd_open,

    .bdrv_co_readv              = nbd_client_co_readv,

    .bdrv_co_writev_flags       = nbd_client_co_writev,

    .bdrv_co_preadv             = nbd_client_co_preadv,

    .bdrv_co_pwritev            = nbd_client_co_pwritev,

    .bdrv_close                 = nbd_close,

    .bdrv_co_flush_to_os        = nbd_co_flush,

    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
@@ -474,8 +474,8 @@ static BlockDriver bdrv_nbd_unix = { 
    .instance_size              = sizeof(BDRVNBDState),

    .bdrv_parse_filename        = nbd_parse_filename,

    .bdrv_file_open             = nbd_open,

    .bdrv_co_readv              = nbd_client_co_readv,

    .bdrv_co_writev_flags       = nbd_client_co_writev,

    .bdrv_co_preadv             = nbd_client_co_preadv,

    .bdrv_co_pwritev            = nbd_client_co_pwritev,

    .bdrv_close                 = nbd_close,

    .bdrv_co_flush_to_os        = nbd_co_flush,

    .bdrv_co_pdiscard           = nbd_client_co_pdiscard,

include/block/nbd.h

+0 −1
Original line number Diff line number Diff line
@@ -77,7 +77,6 @@ enum { 


/* Maximum size of a single READ/WRITE data buffer */

#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)

#define NBD_MAX_SECTORS (NBD_MAX_BUFFER_SIZE / BDRV_SECTOR_SIZE)



/* Maximum size of an export name. The NBD spec requires 256 and

 * suggests that servers support up to 4096, but we stick to only the