kclient: fix division lameness in calc_file_object_mapping

diff --git a/src/kernel/osdmap.c b/src/kernel/osdmap.c
index a1d85f103fff8f3a992e68eb60aeb1105eaed5b2..9dcfee397846e0812e5a3d7b06328bc36242969c 100644 (file)
--- a/src/kernel/osdmap.c
+++ b/src/kernel/osdmap.c
@@ -526,29 +526,34 @@ void calc_file_object_mapping(struct ceph_file_layout *layout,
                              struct ceph_object *oid,
                              __u64 *oxoff, __u64 *oxlen)
 {
-       unsigned su, stripeno, stripepos, objsetno;
-       unsigned su_per_object;
-       unsigned stripe_len = layout->fl_stripe_count * layout->fl_stripe_unit;
-       unsigned first_oxlen;
-       loff_t t;
-
-       /*su_per_object = layout->fl_object_size / layout->fl_stripe_unit; */
-       su_per_object = le32_to_cpu(layout->fl_object_size);
-       do_div(su_per_object, le32_to_cpu(layout->fl_stripe_unit));
-
-       BUG_ON((le32_to_cpu(layout->fl_stripe_unit) & ~PAGE_MASK) != 0);
-       /* su = *off / layout->fl_stripe_unit; */
-       su = *off;
-       do_div(su, le32_to_cpu(layout->fl_stripe_unit));
-       /* stripeno = su / layout->fl_stripe_count;
-          stripepos = su % layout->fl_stripe_count; */
-       stripeno = su;
-       stripepos = do_div(stripeno, le32_to_cpu(layout->fl_stripe_count));
-       /* objsetno = stripeno / su_per_object; */
-       objsetno = stripeno;
-       do_div(objsetno, su_per_object);
-
-       oid->bno = objsetno * le32_to_cpu(layout->fl_stripe_count) + stripepos;
+       u32 osize = le32_to_cpu(layout->fl_object_size);
+       u32 su = le32_to_cpu(layout->fl_stripe_unit);
+       u32 sc = le32_to_cpu(layout->fl_stripe_count);
+       u32 stripe_len = layout->fl_stripe_count * layout->fl_stripe_unit;
+       u32 bl, stripeno, stripepos, objsetno;
+       u32 su_per_object;
+       u32 first_oxlen;
+       u64 t;
+
+       dout(80, "mapping %llu~%llu  osize %u fl_su %u\n", *off, *len,
+            osize, su);
+       su_per_object = osize / layout->fl_stripe_unit;
+       dout(80, "osize %u / su %u = su_per_object %u\n", osize, su,
+            su_per_object);
+
+       BUG_ON((su & ~PAGE_MASK) != 0);
+       /* bl = *off / su; */
+       t = *off;
+       do_div(t, su);
+       bl = t;
+       dout(80, "off %llu / su %u = bl %u\n", *off, su, bl);
+       
+       stripeno = bl / sc;
+       stripepos = bl % sc;
+       objsetno = stripeno / su_per_object;
+
+       oid->bno = objsetno * sc + stripepos;
+       dout(80, "objset %u * sc %u = bno %u\n", objsetno, sc, oid->bno);
        /* *oxoff = *off / layout->fl_stripe_unit; */
        t = *off;
        *oxoff = do_div(t, le32_to_cpu(layout->fl_stripe_unit));
@@ -557,14 +562,14 @@ void calc_file_object_mapping(struct ceph_file_layout *layout,
 
        /* multiple stripe units across this object? */
        t = *len;
-       while (t > stripe_len && *oxoff + *oxlen < 
-              le32_to_cpu(layout->fl_object_size)) {
-               *oxlen += min_t(loff_t, le32_to_cpu(layout->fl_stripe_unit), t);
+       while (t > stripe_len && *oxoff + *oxlen < osize) {
+               *oxlen += min_t(loff_t, su, t);
                t -= stripe_len;
        }
 
        *off += first_oxlen;
        *len -= *oxlen;
+       dout(80, " obj extent %llu~%llu\n", *off, *len);
 }
 
 /*