Commit 1b8bbb46 authored by MORITA Kazutaka's avatar MORITA Kazutaka Committed by Stefan Hajnoczi
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sheepdog: add support for connecting to unix domain socket 

This patch adds support for a unix domain socket for a connection
between qemu and local sheepdog server.  You can use the unix domain
socket with the following syntax:

 $ qemu sheepdog+unix:///<vdiname

>?socket=<socket path>[#snapid]

Signed-off-by: default avatarMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 25af257d

block/sheepdog.c

+70 −12
Original line number Diff line number Diff line
@@ -299,6 +299,7 @@ typedef struct BDRVSheepdogState { 
    uint32_t cache_flags;



    char *host_spec;

    bool is_unix;

    int fd;



    CoMutex lock;
@@ -451,8 +452,19 @@ static int connect_to_sdog(BDRVSheepdogState *s) 
    int fd;

    Error *err = NULL;



    if (s->is_unix) {

        fd = unix_connect(s->host_spec, &err);

    } else {

        fd = inet_connect(s->host_spec, &err);



        if (err == NULL) {

            int ret = socket_set_nodelay(fd);

            if (ret < 0) {

                error_report("%s", strerror(errno));

            }

        }

    }



    if (err != NULL) {

        qerror_report_err(err);

        error_free(err);
@@ -757,7 +769,7 @@ static int aio_flush_request(void *opaque) 
 */

static int get_sheep_fd(BDRVSheepdogState *s)

{

    int ret, fd;

    int fd;



    fd = connect_to_sdog(s);

    if (fd < 0) {
@@ -766,13 +778,6 @@ static int get_sheep_fd(BDRVSheepdogState *s) 


    socket_set_nonblock(fd);



    ret = socket_set_nodelay(fd);

    if (ret) {

        error_report("%s", strerror(errno));

        closesocket(fd);

        return -errno;

    }



    qemu_aio_set_fd_handler(fd, co_read_response, NULL, aio_flush_request, s);

    return fd;

}
@@ -789,15 +794,42 @@ static int sd_parse_uri(BDRVSheepdogState *s, const char *filename, 
        return -EINVAL;

    }



    /* transport */

    if (!strcmp(uri->scheme, "sheepdog")) {

        s->is_unix = false;

    } else if (!strcmp(uri->scheme, "sheepdog+tcp")) {

        s->is_unix = false;

    } else if (!strcmp(uri->scheme, "sheepdog+unix")) {

        s->is_unix = true;

    } else {

        ret = -EINVAL;

        goto out;

    }



    if (uri->path == NULL || !strcmp(uri->path, "/")) {

        ret = -EINVAL;

        goto out;

    }

    pstrcpy(vdi, SD_MAX_VDI_LEN, uri->path + 1);



    qp = query_params_parse(uri->query);

    if (qp->n > 1 || (s->is_unix && !qp->n) || (!s->is_unix && qp->n)) {

        ret = -EINVAL;

        goto out;

    }



    if (s->is_unix) {

        /* sheepdog+unix:///vdiname?socket=path */

        if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {

            ret = -EINVAL;

            goto out;

        }

        s->host_spec = g_strdup(qp->p[0].value);

    } else {

        /* sheepdog[+tcp]://[host:port]/vdiname */

        s->host_spec = g_strdup_printf("%s:%d", uri->server ?: SD_DEFAULT_ADDR,

                                       uri->port ?: SD_DEFAULT_PORT);

    }



    /* snapshot tag */

    if (uri->fragment) {
@@ -2098,9 +2130,35 @@ static BlockDriver bdrv_sheepdog_tcp = { 
    .create_options = sd_create_options,

};



static BlockDriver bdrv_sheepdog_unix = {

    .format_name    = "sheepdog",

    .protocol_name  = "sheepdog+unix",

    .instance_size  = sizeof(BDRVSheepdogState),

    .bdrv_file_open = sd_open,

    .bdrv_close     = sd_close,

    .bdrv_create    = sd_create,

    .bdrv_getlength = sd_getlength,

    .bdrv_truncate  = sd_truncate,



    .bdrv_co_readv  = sd_co_readv,

    .bdrv_co_writev = sd_co_writev,

    .bdrv_co_flush_to_disk  = sd_co_flush_to_disk,



    .bdrv_snapshot_create   = sd_snapshot_create,

    .bdrv_snapshot_goto     = sd_snapshot_goto,

    .bdrv_snapshot_delete   = sd_snapshot_delete,

    .bdrv_snapshot_list     = sd_snapshot_list,



    .bdrv_save_vmstate  = sd_save_vmstate,

    .bdrv_load_vmstate  = sd_load_vmstate,



    .create_options = sd_create_options,

};



static void bdrv_sheepdog_init(void)

{

    bdrv_register(&bdrv_sheepdog);

    bdrv_register(&bdrv_sheepdog_tcp);

    bdrv_register(&bdrv_sheepdog_unix);

}

block_init(bdrv_sheepdog_init);

qemu-doc.texi

+6 −0
Original line number Diff line number Diff line
@@ -865,6 +865,12 @@ qemu-img create -b sheepdog:///@var{base}#@var{tag} sheepdog:///@var{image} 
where @var{base} is a image name of the source snapshot and @var{tag}

is its tag name.



You can use an unix socket instead of an inet socket:



@example

qemu-system-i386 sheepdog+unix:///@var{image}?socket=@var{path}

@end example



If the Sheepdog daemon doesn't run on the local host, you need to

specify one of the Sheepdog servers to connect to.

@example

qemu-options.hx

+1 −1
Original line number Diff line number Diff line
@@ -2100,7 +2100,7 @@ devices. 


Syntax for specifying a sheepdog device

@example

sheepdog[+tcp]://[host:port]/vdiname[#snapid|#tag]

sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]

@end example



Example