EX-6916 build: fix default_groups handling in ofd

The ofd_procfs_add_brw_stats_symlink() function was missed during
the original kobj_type default_groups change on master because it
is disabled by a LUSTRE_VERSION_CODE > 2.14.53 check.  This causes
a crash at mount time due to accessing the (now) uninitialized
default_attrs fields that are still available in RHEL8.7 kernels.

   Call Trace:
    ofd_device_alloc+0xcb/0x180 [ofd]
    obd_setup+0x10f/0x2c0 [obdclass]
    class_setup+0x575/0x750 [obdclass]
    class_process_config+0xe68/0x1a40 [obdclass]
    class_config_llog_handler+0x92e/0x1410 [obdclass]
    llog_process_thread+0xf16/0x1a30 [obdclass]
    llog_process_thread_daemonize+0x9b/0xe0 [obdclass]
    kthread+0x10b/0x130
    ret_from_fork+0x1f/0x40

Update to using the interop accessor functions provided by LU-16120.

Test-Parameters: trivial testlist=runtests serverdistro=el8.7
Fixes: db7be91e0a ("LU-16120 build: Add support for kobj_type default_groups")
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Change-Id: I0117dc4541230ffc9ff6d366773d859d2fce7057
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50055
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lustre/ofd/ofd_dev.c b/lustre/ofd/ofd_dev.c
index bb1ae40..113ea45 100644 (file)
--- a/lustre/ofd/ofd_dev.c
+++ b/lustre/ofd/ofd_dev.c
@@ -727,28 +727,14 @@ static void ofd_procfs_add_brw_stats_symlink(struct ofd_device *ofd)
        struct obd_device *obd = ofd_obd(ofd);
        struct obd_device *osd_obd = ofd->ofd_osd_exp->exp_obd;
        const struct kobj_type *osd_type;
-       int i;
 
        osd_type = get_ktype(&ofd->ofd_osd->dd_kobj);
-       for (i = 0; osd_type->default_attrs[i]; i++) {
-               if (strcmp(osd_type->default_attrs[i]->name,
-                          "read_cache_enable") == 0) {
-                       ofd->ofd_read_cache_enable =
-                               osd_type->default_attrs[i];
-               }
-
-               if (strcmp(osd_type->default_attrs[i]->name,
-                          "readcache_max_filesize") == 0) {
-                       ofd->ofd_read_cache_max_filesize =
-                               osd_type->default_attrs[i];
-               }
-
-               if (strcmp(osd_type->default_attrs[i]->name,
-                          "writethrough_cache_enable") == 0) {
-                       ofd->ofd_write_cache_enable =
-                               osd_type->default_attrs[i];
-               }
-       }
+       ofd->ofd_read_cache_enable =
+               get_attr_by_name(osd_type, "read_cache_enable");
+       ofd->ofd_read_cache_max_filesize =
+               get_attr_by_name(osd_type, "readcache_max_filesize");
+       ofd->ofd_write_cache_enable =
+               get_attr_by_name(osd_type, "writethrough_cache_enable");
 
        if (obd->obd_proc_entry == NULL)
                return;