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 "<imgname>.rbd"
- an object that points to a format 2 header is named "rbd_id.<imgname>"

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 <idryomov@gmail.com>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index bda4dea..3bf93a2 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1965,7 +1965,9 @@ static struct ceph_osd_request *rbd_osd_req_create(
        osd_req->r_priv = obj_request;
 
        osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
-       ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
+       if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
+                            obj_request->object_name))
+               goto fail;
 
        if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
                goto fail;
@@ -2017,7 +2019,9 @@ rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
        osd_req->r_priv = obj_request;
 
        osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
-       ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
+       if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
+                            obj_request->object_name))
+               goto fail;
 
        if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
                goto fail;

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 6fee7e0..6f28dd9 100644 (file)
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1758,9 +1758,7 @@ static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
        rd_req->r_flags = CEPH_OSD_FLAG_READ;
        osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
        rd_req->r_base_oloc.pool = pool;
-       snprintf(rd_req->r_base_oid.name, sizeof(rd_req->r_base_oid.name),
-                "%llx.00000000", ci->i_vino.ino);
-       rd_req->r_base_oid.name_len = strlen(rd_req->r_base_oid.name);
+       ceph_oid_printf(&rd_req->r_base_oid, "%llx.00000000", ci->i_vino.ino);
 
        err = ceph_osdc_alloc_messages(rd_req, GFP_NOFS);
        if (err)
@@ -1777,7 +1775,7 @@ static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
                          CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK;
        osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
        wr_req->r_base_oloc.pool = pool;
-       wr_req->r_base_oid = rd_req->r_base_oid;
+       ceph_oid_copy(&wr_req->r_base_oid, &rd_req->r_base_oid);
 
        err = ceph_osdc_alloc_messages(wr_req, GFP_NOFS);
        if (err)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 5d46d10..9d47039 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -715,7 +715,7 @@ static void ceph_aio_retry_work(struct work_struct *work)
                        CEPH_OSD_FLAG_ONDISK |
                        CEPH_OSD_FLAG_WRITE;
        req->r_base_oloc = orig_req->r_base_oloc;
-       req->r_base_oid = orig_req->r_base_oid;
+       ceph_oid_copy(&req->r_base_oid, &orig_req->r_base_oid);
 
        ret = ceph_osdc_alloc_messages(req, GFP_NOFS);
        if (ret) {

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index f851d8d..db29670 100644 (file)
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -213,7 +213,7 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg)
                 ceph_ino(inode), dl.object_no);
 
        oloc.pool = ceph_file_layout_pg_pool(ci->i_layout);
-       ceph_oid_set_name(&oid, dl.object_name);
+       ceph_oid_printf(&oid, "%s", dl.object_name);
 
        r = ceph_oloc_oid_to_pg(osdc->osdmap, &oloc, &oid, &pgid);
        if (r < 0) {

diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index e55c08b..777a294 100644 (file)
--- 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: <imgname> in "<imgname>.rbd"/"rbd_id.<imgname>" 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 &&

diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
index b902fbc..6f84132 100644 (file)
--- a/net/ceph/debugfs.c
+++ b/net/ceph/debugfs.c
@@ -161,7 +161,7 @@ static int osdc_show(struct seq_file *s, void *pp)
                           req->r_osd ? req->r_osd->o_osd : -1,
                           req->r_pgid.pool, req->r_pgid.seed);
 
-               seq_printf(s, "%.*s", req->r_base_oid.name_len,
+               seq_printf(s, "%*pE", req->r_base_oid.name_len,
                           req->r_base_oid.name);
 
                if (req->r_reassert_version.epoch)

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 75e27bd..95910ae 100644 (file)
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -334,7 +334,10 @@ static void ceph_osdc_release_request(struct kref *kref)
        for (which = 0; which < req->r_num_ops; which++)
                osd_req_op_data_release(req, which);
 
+       ceph_oid_destroy(&req->r_base_oid);
+       ceph_oid_destroy(&req->r_target_oid);
        ceph_put_snap_context(req->r_snapc);
+
        if (req->r_mempool)
                mempool_free(req, req->r_osdc->req_mempool);
        else if (req->r_num_ops <= CEPH_OSD_SLAB_OPS)
@@ -401,7 +404,9 @@ struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
        INIT_LIST_HEAD(&req->r_req_lru_item);
        INIT_LIST_HEAD(&req->r_osd_item);
 
+       ceph_oid_init(&req->r_base_oid);
        req->r_base_oloc.pool = -1;
+       ceph_oid_init(&req->r_target_oid);
        req->r_target_oloc.pool = -1;
 
        dout("%s req %p\n", __func__, req);
@@ -415,6 +420,8 @@ int ceph_osdc_alloc_messages(struct ceph_osd_request *req, gfp_t gfp)
        struct ceph_msg *msg;
        int msg_size;
 
+       WARN_ON(ceph_oid_empty(&req->r_base_oid));
+
        /* create request message */
        msg_size = 4 + 4 + 4; /* client_inc, osdmap_epoch, flags */
        msg_size += 4 + 4 + 4 + 8; /* mtime, reassert_version */
@@ -859,10 +866,7 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
        }
 
        req->r_base_oloc.pool = ceph_file_layout_pg_pool(*layout);
-
-       snprintf(req->r_base_oid.name, sizeof(req->r_base_oid.name),
-                "%llx.%08llx", vino.ino, objnum);
-       req->r_base_oid.name_len = strlen(req->r_base_oid.name);
+       ceph_oid_printf(&req->r_base_oid, "%llx.%08llx", vino.ino, objnum);
 
        r = ceph_osdc_alloc_messages(req, GFP_NOFS);
        if (r)
@@ -1410,7 +1414,7 @@ static int __calc_request_pg(struct ceph_osdmap *osdmap,
                req->r_target_oloc = req->r_base_oloc; /* struct */
                need_check_tiering = true;
        }
-       if (req->r_target_oid.name_len == 0) {
+       if (ceph_oid_empty(&req->r_target_oid)) {
                ceph_oid_copy(&req->r_target_oid, &req->r_base_oid);
                need_check_tiering = true;
        }
@@ -2501,7 +2505,7 @@ void ceph_osdc_build_request(struct ceph_osd_request *req, u64 off,
        /* oid */
        ceph_encode_32(&p, req->r_base_oid.name_len);
        memcpy(p, req->r_base_oid.name, req->r_base_oid.name_len);
-       dout("oid '%.*s' len %d\n", req->r_base_oid.name_len,
+       dout("oid %*pE len %d\n", req->r_base_oid.name_len,
             req->r_base_oid.name, req->r_base_oid.name_len);
        p += req->r_base_oid.name_len;
 

diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 243574c..4668b87 100644 (file)
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1381,8 +1381,99 @@ bad:
        return ERR_PTR(err);
 }
 
+void ceph_oid_copy(struct ceph_object_id *dest,
+                  const struct ceph_object_id *src)
+{
+       WARN_ON(!ceph_oid_empty(dest));
+
+       if (src->name != src->inline_name) {
+               /* very rare, see ceph_object_id definition */
+               dest->name = kmalloc(src->name_len + 1,
+                                    GFP_NOIO | __GFP_NOFAIL);
+       }
 
+       memcpy(dest->name, src->name, src->name_len + 1);
+       dest->name_len = src->name_len;
+}
+EXPORT_SYMBOL(ceph_oid_copy);
 
+static __printf(2, 0)
+int oid_printf_vargs(struct ceph_object_id *oid, const char *fmt, va_list ap)
+{
+       int len;
+
+       WARN_ON(!ceph_oid_empty(oid));
+
+       len = vsnprintf(oid->inline_name, sizeof(oid->inline_name), fmt, ap);
+       if (len >= sizeof(oid->inline_name))
+               return len;
+
+       oid->name_len = len;
+       return 0;
+}
+
+/*
+ * If oid doesn't fit into inline buffer, BUG.
+ */
+void ceph_oid_printf(struct ceph_object_id *oid, const char *fmt, ...)
+{
+       va_list ap;
+
+       va_start(ap, fmt);
+       BUG_ON(oid_printf_vargs(oid, fmt, ap));
+       va_end(ap);
+}
+EXPORT_SYMBOL(ceph_oid_printf);
+
+static __printf(3, 0)
+int oid_aprintf_vargs(struct ceph_object_id *oid, gfp_t gfp,
+                     const char *fmt, va_list ap)
+{
+       va_list aq;
+       int len;
+
+       va_copy(aq, ap);
+       len = oid_printf_vargs(oid, fmt, aq);
+       va_end(aq);
+
+       if (len) {
+               char *external_name;
+
+               external_name = kmalloc(len + 1, gfp);
+               if (!external_name)
+                       return -ENOMEM;
+
+               oid->name = external_name;
+               WARN_ON(vsnprintf(oid->name, len + 1, fmt, ap) != len);
+               oid->name_len = len;
+       }
+
+       return 0;
+}
+
+/*
+ * If oid doesn't fit into inline buffer, allocate.
+ */
+int ceph_oid_aprintf(struct ceph_object_id *oid, gfp_t gfp,
+                    const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
+
+       va_start(ap, fmt);
+       ret = oid_aprintf_vargs(oid, gfp, fmt, ap);
+       va_end(ap);
+
+       return ret;
+}
+EXPORT_SYMBOL(ceph_oid_aprintf);
+
+void ceph_oid_destroy(struct ceph_object_id *oid)
+{
+       if (oid->name != oid->inline_name)
+               kfree(oid->name);
+}
+EXPORT_SYMBOL(ceph_oid_destroy);
 
 /*
  * calculate file layout from given offset, length.
@@ -1474,7 +1565,7 @@ int ceph_oloc_oid_to_pg(struct ceph_osdmap *osdmap,
        pg_out->seed = ceph_str_hash(pi->object_hash, oid->name,
                                     oid->name_len);
 
-       dout("%s '%.*s' pgid %llu.%x\n", __func__, oid->name_len, oid->name,
+       dout("%s %*pE pgid %llu.%x\n", __func__, oid->name_len, oid->name,
             pg_out->pool, pg_out->seed);
        return 0;
 }