In general, I like the approach. I am concerned about passing a void* + length to specify the option value since you really can't protect against the user providing data in the incorrect format. For example, if the backend treated RBD_OPTION_STRIPE_UNIT as a 4byte int, what happens if someone passes a 2- or 8-byte int or a 4-byte char* string? Therefore, I would vote for passing strings a la librados rados_conf_set. Perhaps rbd_create4 and rbd_clone3 should move the order and features options to rbd_image_options_t as well? -- Jason Dillaman ----- Original Message ----- > From: "Mykola Golub" <mgolub@xxxxxxxxxxxx> > To: ceph-devel@xxxxxxxxxxxxxxx > Cc: "Jason Dillaman" <dillaman@xxxxxxxxxx>, "Josh Durgin" <jdurgin@xxxxxxxxxx> > Sent: Wednesday, September 30, 2015 2:50:45 AM > Subject: CEPH_RBD_API: options on image create > > Hi, > > It was mentioned several times eralier that it would be nice to pass > options as key/value configuration pairs on image create instead of > expanding rbd_create/rbd_clone/rbd_copy for every possible > configuration override. > > What do you think about this API? > > Introduce rbd_image_options_t and functions to manipulate it: > > int rbd_image_options_create(rbd_image_options_t* opts); > > void rbd_image_options_destroy(rbd_image_options_t opts); > > int rbd_image_options_set(rbd_image_options_t opts, int optname, > const void* optval, size_t optlen); > > int rbd_image_options_get(rbd_image_options_t opts, int optname, > void* optval, size_t* optlen); > > void rbd_image_options_iterate(rbd_image_options_t opts, > void (*func)(int* optname, void* optval, > size_t* optlen)); > > Functions that return a value return 0 on success, and -ERROR on > failure. > > optname is a constant like RBD_OPTION_STRIPE_UNIT, > RBD_OPTION_STRIPE_COUNT... > > Pass options as additional argument to rbd_create, rbd_clone (and may > be rbd_copy) functions: > > int rbd_create4(rados_ioctx_t io, const char *name, uint64_t size, > uint64_t features, int *order, rbd_image_options_t opts); > > int rbd_clone3(rados_ioctx_t p_ioctx, const char *p_name, > const char *p_snapname, rados_ioctx_t c_ioctx, > const char *c_name, uint64_t features, int *c_order, > rbd_image_options_t opts); > > int rbd_copy3(rbd_image_t src, rbd_image_t dest, rbd_image_options_t opts); > // possibly > > > Example: > > rbd_image_options_t opts; > int r; > r = rbd_image_options_create(&opts); > assert(r == 0); > uint64_t stripe_unit = 65536; > r = rbd_image_options_set(opts, RBD_OPTION_STRIPE_UNIT, > &stripe_unit, size_of(stripe_unit)); > assert(r == 0); > uint64_t stripe_count = 16; > r = rbd_image_options_set(opts, RBD_OPTION_STRIPE_COUNT, > &stripe_count, size_of(stripe_count)); > assert(r == 0); > const char* journal_object_pool = "journal"; > r = rbd_image_options_set(opts, RBD_OPTION_JOURNAL_OBJECT_POOL, > journal_object_pool, strlen(journal_object_pool) + > 1); > assert(r == 0); > r = rbd_create4(io, name, size, features, int *order, rbd_image_options_t > opts); > > cleanup: > rbd_image_options_destroy(opts); > > -- > Mykola Golub > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
