libceph: define ceph_osd_data_length()

One more osd data helper, which returns the length of the
data item, regardless of its type.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 26 insertions, 5 deletions

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index b399e8a18f2b..e197c5c0b3a2 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -117,6 +117,25 @@ void ceph_osd_data_bio_init(struct ceph_osd_data *osd_data,
 EXPORT_SYMBOL(ceph_osd_data_bio_init);
 #endif /* CONFIG_BLOCK */
 
+static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
+{
+        switch (osd_data->type) {
+        case CEPH_OSD_DATA_TYPE_NONE:
+                return 0;
+        case CEPH_OSD_DATA_TYPE_PAGES:
+                return osd_data->length;
+        case CEPH_OSD_DATA_TYPE_PAGELIST:
+                return (u64)osd_data->pagelist->length;
+#ifdef CONFIG_BLOCK
+        case CEPH_OSD_DATA_TYPE_BIO:
+                return (u64)osd_data->bio_length;
+#endif /* CONFIG_BLOCK */
+        default:
+                WARN(true, "unrecognized data type %d\n", (int)osd_data->type);
+                return 0;
+        }
+}
+
 static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
 {
         if (osd_data->type != CEPH_OSD_DATA_TYPE_PAGES)
@@ -1887,17 +1906,19 @@ bad:
 static void ceph_osdc_msg_data_set(struct ceph_msg *msg,
                                 struct ceph_osd_data *osd_data)
 {
+        u64 length = ceph_osd_data_length(osd_data);
+
         if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
-                BUG_ON(osd_data->length > (u64) SIZE_MAX);
-                if (osd_data->length)
+                BUG_ON(length > (u64) SIZE_MAX);
+                if (length)
                         ceph_msg_data_set_pages(msg, osd_data->pages,
-                                osd_data->length, osd_data->alignment);
+                                        length, osd_data->alignment);
         } else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
-                BUG_ON(!osd_data->pagelist->length);
+                BUG_ON(!length);
                 ceph_msg_data_set_pagelist(msg, osd_data->pagelist);
 #ifdef CONFIG_BLOCK
         } else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
-                ceph_msg_data_set_bio(msg, osd_data->bio, osd_data->bio_length);
+                ceph_msg_data_set_bio(msg, osd_data->bio, length);
 #endif
         } else {
                 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_NONE);