LU-12098 mdd: explicitly clear changelogs on deregister

[fs/lustre-release.git] / lustre / mdd / mdd_device.c

diff --git a/lustre/mdd/mdd_device.c b/lustre/mdd/mdd_device.c
index 4bf260f..c6caae2 100644 (file)
--- a/lustre/mdd/mdd_device.c
+++ b/lustre/mdd/mdd_device.c
@@ -1640,6 +1640,8 @@ int mdd_changelog_user_purge(const struct lu_env *env,
                              mdd_changelog_user_purge_cb, &mcup,
                              0, 0);
 
+       OBD_FAIL_TIMEOUT(OBD_FAIL_LLOG_PURGE_DELAY, cfs_fail_val);
+
        if ((rc == 0) && (mcup.mcup_usercount == 0)) {
                spin_lock(&mdd->mdd_cl.mc_user_lock);
                if (mdd->mdd_cl.mc_users == 0) {
@@ -1887,7 +1889,15 @@ static int mdd_iocontrol(const struct lu_env *env, struct md_device *m,
                if (unlikely(!barrier_entry(mdd->mdd_bottom)))
                        RETURN(-EINPROGRESS);
 
-               rc = mdd_changelog_user_purge(env, mdd, data->ioc_u32_1);
+               /* explicitly clear changelog first, to protect from crash in
+                * the middle of purge that would lead to unregistered consumer
+                * but pending changelog entries
+                */
+               rc = mdd_changelog_clear(env, mdd, data->ioc_u32_1, 0);
+               if (!rc)
+                       rc = mdd_changelog_user_purge(env,
+                                                     mdd, data->ioc_u32_1);
+
                barrier_exit(mdd->mdd_bottom);
                break;
        default: