+static int mdd_changelog_user_register(const struct lu_env *env,
+ struct mdd_device *mdd, int *id)
+{
+ struct llog_ctxt *ctxt;
+ struct llog_changelog_user_rec *rec;
+ int rc;
+ ENTRY;
+
+ ctxt = llog_get_context(mdd2obd_dev(mdd),
+ LLOG_CHANGELOG_USER_ORIG_CTXT);
+ if (ctxt == NULL)
+ RETURN(-ENXIO);
+
+ OBD_ALLOC_PTR(rec);
+ if (rec == NULL) {
+ llog_ctxt_put(ctxt);
+ RETURN(-ENOMEM);
+ }
+
+ /* Assume we want it on since somebody registered */
+ rc = mdd_changelog_on(env, mdd, 1);
+ if (rc)
+ GOTO(out, rc);
+
+ rec->cur_hdr.lrh_len = sizeof(*rec);
+ rec->cur_hdr.lrh_type = CHANGELOG_USER_REC;
+ cfs_spin_lock(&mdd->mdd_cl.mc_user_lock);
+ if (mdd->mdd_cl.mc_lastuser == (unsigned int)(-1)) {
+ cfs_spin_unlock(&mdd->mdd_cl.mc_user_lock);
+ CERROR("Maximum number of changelog users exceeded!\n");
+ GOTO(out, rc = -EOVERFLOW);
+ }
+ *id = rec->cur_id = ++mdd->mdd_cl.mc_lastuser;
+ rec->cur_endrec = mdd->mdd_cl.mc_index;
+ cfs_spin_unlock(&mdd->mdd_cl.mc_user_lock);
+
+ rc = llog_cat_add(env, ctxt->loc_handle, &rec->cur_hdr, NULL, NULL);
+
+ CDEBUG(D_IOCTL, "Registered changelog user %d\n", *id);
+out:
+ OBD_FREE_PTR(rec);
+ llog_ctxt_put(ctxt);
+ RETURN(rc);
+}
+
+struct mdd_changelog_user_data {
+ __u64 mcud_endrec; /**< purge record for this user */
+ __u64 mcud_minrec; /**< lowest changelog recno still referenced */
+ __u32 mcud_id;
+ __u32 mcud_minid; /**< user id with lowest rec reference */
+ __u32 mcud_usercount;
+ int mcud_found:1;
+};
+#define MCUD_UNREGISTER -1LL
+
+/** Two things:
+ * 1. Find the smallest record everyone is willing to purge
+ * 2. Update the last purgeable record for this user
+ */
+static int mdd_changelog_user_purge_cb(const struct lu_env *env,
+ struct llog_handle *llh,
+ struct llog_rec_hdr *hdr, void *data)
+{
+ struct llog_changelog_user_rec *rec;
+ struct mdd_changelog_user_data *mcud = data;
+ int rc;
+
+ ENTRY;
+
+ LASSERT(llh->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN);
+
+ rec = (struct llog_changelog_user_rec *)hdr;
+
+ mcud->mcud_usercount++;
+
+ /* If we have a new endrec for this id, use it for the following
+ min check instead of its old value */
+ if (rec->cur_id == mcud->mcud_id)
+ rec->cur_endrec = max(rec->cur_endrec, mcud->mcud_endrec);
+
+ /* Track the minimum referenced record */
+ if (mcud->mcud_minid == 0 || mcud->mcud_minrec > rec->cur_endrec) {
+ mcud->mcud_minid = rec->cur_id;
+ mcud->mcud_minrec = rec->cur_endrec;
+ }
+
+ if (rec->cur_id != mcud->mcud_id)
+ RETURN(0);
+
+ /* Update this user's record */
+ mcud->mcud_found = 1;
+
+ /* Special case: unregister this user */
+ if (mcud->mcud_endrec == MCUD_UNREGISTER) {
+ struct llog_cookie cookie;
+
+ cookie.lgc_lgl = llh->lgh_id;
+ cookie.lgc_index = hdr->lrh_index;
+
+ rc = llog_cat_cancel_records(env, llh->u.phd.phd_cat_handle,
+ 1, &cookie);
+ if (rc == 0)
+ mcud->mcud_usercount--;
+
+ RETURN(rc);
+ }
+
+ /* Update the endrec */
+ CDEBUG(D_IOCTL, "Rewriting changelog user %d endrec to "LPU64"\n",
+ mcud->mcud_id, rec->cur_endrec);
+
+ /* hdr+1 is loc of data */
+ hdr->lrh_len -= sizeof(*hdr) + sizeof(struct llog_rec_tail);
+ rc = llog_write(env, llh, hdr, NULL, 0, (void *)(hdr + 1),
+ hdr->lrh_index);
+
+ RETURN(rc);
+}
+
+static int mdd_changelog_user_purge(const struct lu_env *env,
+ struct mdd_device *mdd, int id,
+ long long endrec)
+{
+ struct mdd_changelog_user_data data;
+ struct llog_ctxt *ctxt;
+ int rc;
+ ENTRY;
+
+ CDEBUG(D_IOCTL, "Purge request: id=%d, endrec=%lld\n", id, endrec);
+
+ data.mcud_id = id;
+ data.mcud_minid = 0;
+ data.mcud_minrec = 0;
+ data.mcud_usercount = 0;
+ data.mcud_endrec = endrec;
+ cfs_spin_lock(&mdd->mdd_cl.mc_lock);
+ endrec = mdd->mdd_cl.mc_index;
+ cfs_spin_unlock(&mdd->mdd_cl.mc_lock);
+ if ((data.mcud_endrec == 0) ||
+ ((data.mcud_endrec > endrec) &&
+ (data.mcud_endrec != MCUD_UNREGISTER)))
+ data.mcud_endrec = endrec;
+
+ ctxt = llog_get_context(mdd2obd_dev(mdd),
+ LLOG_CHANGELOG_USER_ORIG_CTXT);
+ if (ctxt == NULL)
+ return -ENXIO;
+
+ LASSERT(ctxt->loc_handle->lgh_hdr->llh_flags & LLOG_F_IS_CAT);
+
+ rc = llog_cat_process(env, ctxt->loc_handle,
+ mdd_changelog_user_purge_cb, (void *)&data,
+ 0, 0);
+ if ((rc >= 0) && (data.mcud_minrec > 0)) {
+ CDEBUG(D_IOCTL, "Purging changelog entries up to "LPD64
+ ", referenced by "CHANGELOG_USER_PREFIX"%d\n",
+ data.mcud_minrec, data.mcud_minid);
+ rc = mdd_changelog_llog_cancel(env, mdd, data.mcud_minrec);
+ } else {
+ CWARN("Could not determine changelog records to purge; rc=%d\n",
+ rc);
+ }
+
+ llog_ctxt_put(ctxt);
+
+ if (!data.mcud_found) {
+ CWARN("No entry for user %d. Last changelog reference is "
+ LPD64" by changelog user %d\n", data.mcud_id,
+ data.mcud_minrec, data.mcud_minid);
+ rc = -ENOENT;
+ }
+
+ if (!rc && data.mcud_usercount == 0)
+ /* No more users; turn changelogs off */
+ rc = mdd_changelog_on(env, mdd, 0);
+
+ RETURN (rc);
+}
+
+/** mdd_iocontrol
+ * May be called remotely from mdt_iocontrol_handle or locally from
+ * mdt_iocontrol. Data may be freeform - remote handling doesn't enforce
+ * an obd_ioctl_data format (but local ioctl handler does).
+ * \param cmd - ioc
+ * \param len - data len
+ * \param karg - ioctl data, in kernel space
+ */
+static int mdd_iocontrol(const struct lu_env *env, struct md_device *m,
+ unsigned int cmd, int len, void *karg)
+{
+ struct mdd_device *mdd;
+ struct obd_ioctl_data *data = karg;
+ int rc;
+ ENTRY;
+
+ mdd = lu2mdd_dev(&m->md_lu_dev);
+
+ /* Doesn't use obd_ioctl_data */
+ switch (cmd) {
+ case OBD_IOC_CHANGELOG_CLEAR: {
+ struct changelog_setinfo *cs = karg;
+ rc = mdd_changelog_user_purge(env, mdd, cs->cs_id,
+ cs->cs_recno);
+ RETURN(rc);
+ }
+ case OBD_IOC_GET_MNTOPT: {
+ mntopt_t *mntopts = (mntopt_t *)karg;
+ *mntopts = mdd->mdd_dt_conf.ddp_mntopts;
+ RETURN(0);
+ }
+ case OBD_IOC_START_LFSCK: {
+ struct lfsck_start *start = karg;
+ struct md_lfsck *lfsck = &mdd->mdd_lfsck;
+
+ /* Return the kernel service version. */
+ /* XXX: version can be used for compatibility in the future. */
+ start->ls_version = lfsck->ml_version;
+ rc = mdd_lfsck_start(env, lfsck, start);
+ RETURN(rc);
+ }
+ case OBD_IOC_STOP_LFSCK: {
+ rc = mdd_lfsck_stop(env, &mdd->mdd_lfsck);
+ RETURN(rc);
+ }
+ }
+
+ /* Below ioctls use obd_ioctl_data */
+ if (len != sizeof(*data)) {
+ CERROR("Bad ioctl size %d\n", len);
+ RETURN(-EINVAL);
+ }
+ if (data->ioc_version != OBD_IOCTL_VERSION) {
+ CERROR("Bad magic %x != %x\n", data->ioc_version,
+ OBD_IOCTL_VERSION);
+ RETURN(-EINVAL);
+ }
+
+ switch (cmd) {
+ case OBD_IOC_CHANGELOG_REG:
+ rc = mdd_changelog_user_register(env, mdd, &data->ioc_u32_1);
+ break;
+ case OBD_IOC_CHANGELOG_DEREG:
+ rc = mdd_changelog_user_purge(env, mdd, data->ioc_u32_1,
+ MCUD_UNREGISTER);
+ break;
+ default:
+ rc = -ENOTTY;
+ }
+
+ RETURN (rc);
+}
+