Commit 99a3c89d authored by Josh Durgin's avatar Josh Durgin Committed by Kevin Wolf
Browse files

rbd: make qemu's cache setting override any ceph setting 



To be safe, when cache=none is used ceph settings should not be able
to override it to turn on caching. This was previously possible with
rbd_cache=true in the rbd device configuration or a ceph configuration
file. Similarly, rbd settings could have turned off caching when qemu
requested it, although this would just be a performance problem.

Fix this by changing rbd's cache setting to match qemu after all other
ceph settings have been applied.

Signed-off-by: default avatarJosh Durgin <jdurgin@redhat.com>
Reviewed-by: default avatarJeff Cody <jcody@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 5a8ac6d9

block/rbd.c

+12 −12
Original line number Diff line number Diff line
@@ -460,6 +460,18 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, 
        s->snap = g_strdup(snap_buf);

    }



    if (strstr(conf, "conf=") == NULL) {

        /* try default location, but ignore failure */

        rados_conf_read_file(s->cluster, NULL);

    }



    if (conf[0] != '\0') {

        r = qemu_rbd_set_conf(s->cluster, conf, errp);

        if (r < 0) {

            goto failed_shutdown;

        }

    }



    /*

     * Fallback to more conservative semantics if setting cache

     * options fails. Ignore errors from setting rbd_cache because the
@@ -473,18 +485,6 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, 
        rados_conf_set(s->cluster, "rbd_cache", "true");

    }



    if (strstr(conf, "conf=") == NULL) {

        /* try default location, but ignore failure */

        rados_conf_read_file(s->cluster, NULL);

    }



    if (conf[0] != '\0') {

        r = qemu_rbd_set_conf(s->cluster, conf, errp);

        if (r < 0) {

            goto failed_shutdown;

        }

    }



    r = rados_connect(s->cluster);

    if (r < 0) {

        error_setg(errp, "error connecting");