kclient: avoid zero_user_segment on old kernels

zero_user_segment appeared in 2.6.25.

diff --git a/src/kernel/osd_client.c b/src/kernel/osd_client.c
index ce3a936e56eca5a9a2802dc0366b348cb340aab2..f69d1fbb95e730818dfa56feda38488807f99002 100644 (file)
--- a/src/kernel/osd_client.c
+++ b/src/kernel/osd_client.c
@@ -871,7 +871,7 @@ out:
 }
 
 /*
- * read a single page.
+ * Read a single page.  Return number of bytes read (or zeroed).
  */
 int ceph_osdc_readpage(struct ceph_osd_client *osdc, struct ceph_vino vino,
                       struct ceph_file_layout *layout,
@@ -904,7 +904,11 @@ int ceph_osdc_readpage(struct ceph_osd_client *osdc, struct ceph_vino vino,
        }
        if (read < PAGE_CACHE_SIZE) {
                dout(10, "readpage zeroing %p from %d\n", page, read);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
                zero_user_segment(page, read, PAGE_CACHE_SIZE);
+#else
+               zero_user_page(page, read, PAGE_CACHE_SIZE-read, KM_USER0);
+#endif
        }
 
        ceph_osdc_put_request(req);
@@ -987,13 +991,24 @@ int ceph_osdc_readpages(struct ceph_osd_client *osdc,
                        page = req->r_pages[i];
                        dout(20, "readpages zeroing %d %p from %d\n", i, page,
                             (int)(read & ~PAGE_CACHE_MASK));
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
                        zero_user_segment(page, read & ~PAGE_CACHE_MASK,
                                          PAGE_CACHE_SIZE);
+#else
+                       zero_user_page(page, read & ~PAGE_CACHE_MASK,
+                                      PAGE_CACHE_SIZE - (read & ~PAGE_CACHE_MASK),
+                                      KM_USER0);
+#endif
+
                }
                for (i = read << PAGE_CACHE_SHIFT; i < contig_pages; i++) {
                        page = req->r_pages[i];
                        dout(20, "readpages zeroing %d %p\n", i, page);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
                        zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+#else
+                       zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
+#endif
                }
        }