Currently, most Ceph configuration options are not exposed via QAPI. While it is possible to specify a dedicated Ceph configuration file, specialized options are often only required for a selection of images on the RBD storage, not all of them. To avoid the need to generate a dedicated Ceph configuration file for each image (or for each required combination of options), support a selection of key-value pairs via QAPI.
Initially, this is just 'rbd_cache_policy'. For example, this is useful with small images used as a pflash for EFI variables. Setting the 'rbd_cache_policy' to 'writeback' yields a substantial improvement there [0]. The function qemu_rbd_extract_key_value_pairs() was copied/adapted from the existing qemu_rbd_extract_encryption_create_options(). [0]: https://bugzilla.proxmox.com/show_bug.cgi?id=3329#c9 Signed-off-by: Fiona Ebner <f.eb...@proxmox.com> --- block/rbd.c | 73 ++++++++++++++++++++++++++++++++++++++++++++ qapi/block-core.json | 37 ++++++++++++++++++++++ 2 files changed, 110 insertions(+) diff --git a/block/rbd.c b/block/rbd.c index 7446e66659..2924f23093 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -298,6 +298,27 @@ static int qemu_rbd_set_auth(rados_t cluster, BlockdevOptionsRbd *opts, return 0; } +static int qemu_rbd_set_key_value_pairs(rados_t cluster, + RbdKeyValuePairs *key_value_pairs, + Error **errp) +{ + if (!key_value_pairs) { + return 0; + } + + if (key_value_pairs->has_rbd_cache_policy) { + RbdCachePolicy value = key_value_pairs->rbd_cache_policy; + int r = rados_conf_set(cluster, "rbd_cache_policy", + RbdCachePolicy_str(value)); + if (r < 0) { + error_setg_errno(errp, -r, "could not set 'rbd_cache_policy'"); + return -EINVAL; + } + } + + return 0; +} + static int qemu_rbd_set_keypairs(rados_t cluster, const char *keypairs_json, Error **errp) { @@ -791,6 +812,44 @@ exit: return ret; } +static int qemu_rbd_extract_key_value_pairs( + QemuOpts *opts, + RbdKeyValuePairs **key_value_pairs, + Error **errp) +{ + QDict *opts_qdict; + QDict *key_value_pairs_qdict; + Visitor *v; + int ret = 0; + + opts_qdict = qemu_opts_to_qdict(opts, NULL); + qdict_extract_subqdict(opts_qdict, &key_value_pairs_qdict, + "key-value-pairs."); + qobject_unref(opts_qdict); + if (!qdict_size(key_value_pairs_qdict)) { + *key_value_pairs = NULL; + goto exit; + } + + /* Convert options into a QAPI object */ + v = qobject_input_visitor_new_flat_confused(key_value_pairs_qdict, errp); + if (!v) { + ret = -EINVAL; + goto exit; + } + + visit_type_RbdKeyValuePairs(v, NULL, key_value_pairs, errp); + visit_free(v); + if (!*key_value_pairs) { + ret = -EINVAL; + goto exit; + } + +exit: + qobject_unref(key_value_pairs_qdict); + return ret; +} + static int coroutine_fn qemu_rbd_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, @@ -800,6 +859,7 @@ static int coroutine_fn qemu_rbd_co_create_opts(BlockDriver *drv, BlockdevCreateOptionsRbd *rbd_opts; BlockdevOptionsRbd *loc; RbdEncryptionCreateOptions *encrypt = NULL; + RbdKeyValuePairs *key_value_pairs = NULL; Error *local_err = NULL; const char *keypairs, *password_secret; QDict *options = NULL; @@ -848,6 +908,13 @@ static int coroutine_fn qemu_rbd_co_create_opts(BlockDriver *drv, loc->image = g_strdup(qdict_get_try_str(options, "image")); keypairs = qdict_get_try_str(options, "=keyvalue-pairs"); + /* These are the key-value pairs coming in via the QAPI. */ + ret = qemu_rbd_extract_key_value_pairs(opts, &key_value_pairs, errp); + if (ret < 0) { + goto exit; + } + loc->key_value_pairs = key_value_pairs; + ret = qemu_rbd_do_create(create_options, keypairs, password_secret, errp); if (ret < 0) { goto exit; @@ -937,6 +1004,12 @@ static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx, goto failed_shutdown; } + /* For the key-value pairs coming via QAPI. */ + r = qemu_rbd_set_key_value_pairs(*cluster, opts->key_value_pairs, errp); + if (r < 0) { + goto failed_shutdown; + } + if (mon_host) { r = rados_conf_set(*cluster, "mon_host", mon_host); if (r < 0) { diff --git a/qapi/block-core.json b/qapi/block-core.json index 91c70e24a7..4666765e66 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -4301,6 +4301,39 @@ 'data': { 'luks': 'RbdEncryptionCreateOptionsLUKS', 'luks2': 'RbdEncryptionCreateOptionsLUKS2' } } +## +# @RbdCachePolicy: +# +# An enumeration of values for the 'rbd_cache_policy' Ceph +# configuration setting. See the Ceph documentation for details. +# +# @writearound: cachable writes return immediately, reads are not +# served from the cache. +# +# @writeback: cachable writes return immediately, reads are served +# from the cache. +# +# @writethrough: writes return only when the data is on disk for all +# replicas, reads are served from the cache. +# +# Since 10.1 +## +{ 'enum' : 'RbdCachePolicy', + 'data' : [ 'writearound', 'writeback', 'writethrough' ] } + + +## +# @RbdKeyValuePairs: +# +# Key-value pairs for Ceph configuration. +# +# @rbd-cache-policy: Ceph configuration option 'rbd_cache_policy'. +# +# Since 10.1 +## +{ 'struct': 'RbdKeyValuePairs', + 'data': { '*rbd-cache-policy': 'RbdCachePolicy' } } + ## # @BlockdevOptionsRbd: # @@ -4327,6 +4360,9 @@ # authentication. This maps to Ceph configuration option "key". # (Since 3.0) # +# @key-value-pairs: Key-value pairs for additional Ceph configuraton. +# (Since 10.1) +# # @server: Monitor host address and port. This maps to the "mon_host" # Ceph option. # @@ -4342,6 +4378,7 @@ '*user': 'str', '*auth-client-required': ['RbdAuthMode'], '*key-secret': 'str', + '*key-value-pairs' : 'RbdKeyValuePairs', '*server': ['InetSocketAddressBase'] } } ## -- 2.39.5
