From d30291b985d1854565d7f2c82a4457869d5265e8 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Fri, 29 Apr 2016 19:54:20 +0200 Subject: libceph: variable-sized ceph_object_id Currently ceph_object_id can hold object names of up to 100 (CEPH_MAX_OID_NAME_LEN) characters. This is enough for all use cases, expect one - long rbd image names: - a format 1 header is named ".rbd" - an object that points to a format 2 header is named "rbd_id." We operate on these potentially long-named objects during rbd map, and, for format 1 images, during header refresh. (A format 2 header name is a small system-generated string.) Lift this 100 character limit by making ceph_object_id be able to point to an externally-allocated string. Apart from being able to work with almost arbitrarily-long named objects, this allows us to reduce the size of ceph_object_id from >100 bytes to 64 bytes. Signed-off-by: Ilya Dryomov --- include/linux/ceph/osdmap.h | 62 +++++++++++++++++++++++++++------------------ 1 file changed, 37 insertions(+), 25 deletions(-) (limited to 'include/linux/ceph') diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h index e55c08bc3a96..777a29412706 100644 --- a/include/linux/ceph/osdmap.h +++ b/include/linux/ceph/osdmap.h @@ -64,11 +64,47 @@ struct ceph_object_locator { */ #define CEPH_MAX_OID_NAME_LEN 100 +/* + * 51-char inline_name is long enough for all cephfs and all but one + * rbd requests: in ".rbd"/"rbd_id." can be + * arbitrarily long (~PAGE_SIZE). It's done once during rbd map; all + * other rbd requests fit into inline_name. + * + * Makes ceph_object_id 64 bytes on 64-bit. + */ +#define CEPH_OID_INLINE_LEN 52 + +/* + * Both inline and external buffers have space for a NUL-terminator, + * which is carried around. It's not required though - RADOS object + * names don't have to be NUL-terminated and may contain NULs. + */ struct ceph_object_id { - char name[CEPH_MAX_OID_NAME_LEN]; + char *name; + char inline_name[CEPH_OID_INLINE_LEN]; int name_len; }; +static inline void ceph_oid_init(struct ceph_object_id *oid) +{ + oid->name = oid->inline_name; + oid->name_len = 0; +} + +static inline bool ceph_oid_empty(const struct ceph_object_id *oid) +{ + return oid->name == oid->inline_name && !oid->name_len; +} + +void ceph_oid_copy(struct ceph_object_id *dest, + const struct ceph_object_id *src); +__printf(2, 3) +void ceph_oid_printf(struct ceph_object_id *oid, const char *fmt, ...); +__printf(3, 4) +int ceph_oid_aprintf(struct ceph_object_id *oid, gfp_t gfp, + const char *fmt, ...); +void ceph_oid_destroy(struct ceph_object_id *oid); + struct ceph_pg_mapping { struct rb_node node; struct ceph_pg pgid; @@ -113,30 +149,6 @@ struct ceph_osdmap { int crush_scratch_ary[CEPH_PG_MAX_SIZE * 3]; }; -static inline void ceph_oid_set_name(struct ceph_object_id *oid, - const char *name) -{ - int len; - - len = strlen(name); - if (len > sizeof(oid->name)) { - WARN(1, "ceph_oid_set_name '%s' len %d vs %zu, truncating\n", - name, len, sizeof(oid->name)); - len = sizeof(oid->name); - } - - memcpy(oid->name, name, len); - oid->name_len = len; -} - -static inline void ceph_oid_copy(struct ceph_object_id *dest, - struct ceph_object_id *src) -{ - BUG_ON(src->name_len > sizeof(dest->name)); - memcpy(dest->name, src->name, src->name_len); - dest->name_len = src->name_len; -} - static inline int ceph_osd_exists(struct ceph_osdmap *map, int osd) { return osd >= 0 && osd < map->max_osd && -- cgit v1.2.3