Re: [Qemu-devel] [PATCH v4 2/4] rbd: allow configuration of rados from the rbd filename

[Christian Brunner <chb@muc.de>]

Looks good to me:

Reviewed-by: Christian Brunner <chb@muc.de>

2011/5/24 Josh Durgin <josh.durgin@dreamhost.com>:
> The new format is rbd:pool/image[@snapshot][:option1=value1[:option2=value2...]]
> Each option is used to configure rados, and may be any Ceph option, or "conf".
> The "conf" option specifies a Ceph configuration file to read.
>
> This allows rbd volumes from more than one Ceph cluster to be used by
> specifying different monitor addresses, as well as having different
> logging levels or locations for different volumes.
>
> Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
> ---
>  block/rbd.c |  119 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
>  1 files changed, 102 insertions(+), 17 deletions(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index 1c8e7c7..ff74e8b 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -23,13 +23,17 @@
>  /*
>  * When specifying the image filename use:
>  *
> - * rbd:poolname/devicename
> + * rbd:poolname/devicename[@snapshotname][:option1=value1[:option2=value2...]]
>  *
>  * poolname must be the name of an existing rados pool
>  *
>  * devicename is the basename for all objects used to
>  * emulate the raw device.
>  *
> + * Each option given is used to configure rados, and may be
> + * any Ceph option, or "conf". The "conf" option specifies
> + * a Ceph configuration file to read.
> + *
>  * Metadata information (image size, ...) is stored in an
>  * object with the name "devicename.rbd".
>  *
> @@ -122,7 +126,8 @@ static int qemu_rbd_next_tok(char *dst, int dst_len,
>  static int qemu_rbd_parsename(const char *filename,
>                               char *pool, int pool_len,
>                               char *snap, int snap_len,
> -                              char *name, int name_len)
> +                              char *name, int name_len,
> +                              char *conf, int conf_len)
>  {
>     const char *start;
>     char *p, *buf;
> @@ -134,28 +139,84 @@ static int qemu_rbd_parsename(const char *filename,
>
>     buf = qemu_strdup(start);
>     p = buf;
> +    *snap = '\0';
> +    *conf = '\0';
>
>     ret = qemu_rbd_next_tok(pool, pool_len, p, '/', "pool name", &p);
>     if (ret < 0 || !p) {
>         ret = -EINVAL;
>         goto done;
>     }
> -    ret = qemu_rbd_next_tok(name, name_len, p, '@', "object name", &p);
> -    if (ret < 0) {
> -        goto done;
> +
> +    if (strchr(p, '@')) {
> +        ret = qemu_rbd_next_tok(name, name_len, p, '@', "object name", &p);
> +        if (ret < 0) {
> +            goto done;
> +        }
> +        ret = qemu_rbd_next_tok(snap, snap_len, p, ':', "snap name", &p);
> +    } else {
> +        ret = qemu_rbd_next_tok(name, name_len, p, ':', "object name", &p);
>     }
> -    if (!p) {
> -        *snap = '\0';
> +    if (ret < 0 || !p) {
>         goto done;
>     }
>
> -    ret = qemu_rbd_next_tok(snap, snap_len, p, '\0', "snap name", &p);
> +    ret = qemu_rbd_next_tok(conf, conf_len, p, '\0', "configuration", &p);
>
>  done:
>     qemu_free(buf);
>     return ret;
>  }
>
> +static int qemu_rbd_set_conf(rados_t cluster, const char *conf)
> +{
> +    char *p, *buf;
> +    char name[RBD_MAX_CONF_NAME_SIZE];
> +    char value[RBD_MAX_CONF_VAL_SIZE];
> +    int ret = 0;
> +
> +    buf = qemu_strdup(conf);
> +    p = buf;
> +
> +    while (p) {
> +        ret = qemu_rbd_next_tok(name, sizeof(name), p,
> +                                '=', "conf option name", &p);
> +        if (ret < 0) {
> +            break;
> +        }
> +
> +        if (!p) {
> +            error_report("conf option %s has no value", name);
> +            ret = -EINVAL;
> +            break;
> +        }
> +
> +        ret = qemu_rbd_next_tok(value, sizeof(value), p,
> +                                ':', "conf option value", &p);
> +        if (ret < 0) {
> +            break;
> +        }
> +
> +        if (strncmp(name, "conf", strlen("conf"))) {
> +            ret = rados_conf_set(cluster, name, value);
> +            if (ret < 0) {
> +                error_report("invalid conf option %s", name);
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else {
> +            ret = rados_conf_read_file(cluster, value);
> +            if (ret < 0) {
> +                error_report("error reading conf file %s", value);
> +                break;
> +            }
> +        }
> +    }
> +
> +    qemu_free(buf);
> +    return ret;
> +}
> +
>  static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options)
>  {
>     int64_t bytes = 0;
> @@ -164,6 +225,7 @@ static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options)
>     char pool[RBD_MAX_POOL_NAME_SIZE];
>     char name[RBD_MAX_IMAGE_NAME_SIZE];
>     char snap_buf[RBD_MAX_SNAP_NAME_SIZE];
> +    char conf[RBD_MAX_CONF_SIZE];
>     char *snap = NULL;
>     rados_t cluster;
>     rados_ioctx_t io_ctx;
> @@ -171,7 +233,8 @@ static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options)
>
>     if (qemu_rbd_parsename(filename, pool, sizeof(pool),
>                            snap_buf, sizeof(snap_buf),
> -                           name, sizeof(name)) < 0) {
> +                           name, sizeof(name),
> +                           conf, sizeof(conf)) < 0) {
>         return -EINVAL;
>     }
>     if (snap_buf[0] != '\0') {
> @@ -204,8 +267,17 @@ static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options)
>         return -EIO;
>     }
>
> -    if (rados_conf_read_file(cluster, NULL) < 0) {
> -        error_report("error reading config file");
> +    if (strstr(conf, "conf=") == NULL) {
> +        if (rados_conf_read_file(cluster, NULL) < 0) {
> +            error_report("error reading config file");
> +            rados_shutdown(cluster);
> +            return -EIO;
> +        }
> +    }
> +
> +    if (conf[0] != '\0' &&
> +        qemu_rbd_set_conf(cluster, conf) < 0) {
> +        error_report("error setting config options");
>         rados_shutdown(cluster);
>         return -EIO;
>     }
> @@ -315,11 +387,13 @@ static int qemu_rbd_open(BlockDriverState *bs, const char *filename, int flags)
>     BDRVRBDState *s = bs->opaque;
>     char pool[RBD_MAX_POOL_NAME_SIZE];
>     char snap_buf[RBD_MAX_SNAP_NAME_SIZE];
> +    char conf[RBD_MAX_CONF_SIZE];
>     int r;
>
>     if (qemu_rbd_parsename(filename, pool, sizeof(pool),
>                            snap_buf, sizeof(snap_buf),
> -                           s->name, sizeof(s->name)) < 0) {
> +                           s->name, sizeof(s->name),
> +                           conf, sizeof(conf)) < 0) {
>         return -EINVAL;
>     }
>     s->snap = NULL;
> @@ -333,11 +407,22 @@ static int qemu_rbd_open(BlockDriverState *bs, const char *filename, int flags)
>         return r;
>     }
>
> -    r = rados_conf_read_file(s->cluster, NULL);
> -    if (r < 0) {
> -        error_report("error reading config file");
> -        rados_shutdown(s->cluster);
> -        return r;
> +    if (strstr(conf, "conf=") == NULL) {
> +        r = rados_conf_read_file(s->cluster, NULL);
> +        if (r < 0) {
> +            error_report("error reading config file");
> +            rados_shutdown(s->cluster);
> +            return r;
> +        }
> +    }
> +
> +    if (conf[0] != '\0') {
> +        r = qemu_rbd_set_conf(s->cluster, conf);
> +        if (r < 0) {
> +            error_report("error setting config options");
> +            rados_shutdown(s->cluster);
> +            return r;
> +        }
>     }
>
>     r = rados_connect(s->cluster);
> --
> 1.7.2.3
>
>
>