+ * Helper function to handle quota request from slave.
+ *
+ * \param env - is the environment passed by the caller
+ * \param lqe - is the lquota_entry subject to the quota request
+ * \param qmt - is the master device
+ * \param uuid - is the uuid associated with the slave
+ * \param qb_flags - are the quota request flags as packed in the quota_body
+ * \param qb_count - is the amount of quota space the slave wants to
+ * acquire/release
+ * \param qb_usage - is the current space usage on the slave
+ * \param repbody - is the quota_body of reply
+ *
+ * \retval 0 : success
+ * \retval -EDQUOT : out of quota
+ * -EINPROGRESS : inform client to retry write/create
+ * -ve : other appropriate errors
+ */
+int qmt_dqacq0(const struct lu_env *env, struct lquota_entry *lqe,
+ struct qmt_device *qmt, struct obd_uuid *uuid, __u32 qb_flags,
+ __u64 qb_count, __u64 qb_usage, struct quota_body *repbody)
+{
+ struct qmt_thread_info *qti = qmt_info(env);
+ __u64 now, count;
+ struct dt_object *slv_obj = NULL;
+ __u64 slv_granted, slv_granted_bck;
+ struct thandle *th = NULL;
+ int rc, ret;
+ ENTRY;
+
+ LASSERT(uuid != NULL);
+
+ /* initialize reply */
+ memset(repbody, 0, sizeof(*repbody));
+ memcpy(&repbody->qb_id, &lqe->lqe_id, sizeof(repbody->qb_id));
+
+ if (OBD_FAIL_CHECK(OBD_FAIL_QUOTA_RECOVERABLE_ERR))
+ RETURN(-cfs_fail_val);
+
+ /* look-up index file associated with acquiring slave */
+ slv_obj = lquota_disk_slv_find(env, qmt->qmt_child, LQE_ROOT(lqe),
+ lu_object_fid(&LQE_GLB_OBJ(lqe)->do_lu),
+ uuid);
+ if (IS_ERR(slv_obj))
+ GOTO(out, rc = PTR_ERR(slv_obj));
+
+ /* pack slave fid in reply just for sanity check */
+ memcpy(&repbody->qb_slv_fid, lu_object_fid(&slv_obj->do_lu),
+ sizeof(struct lu_fid));
+
+ /* allocate & start transaction with enough credits to update
+ * global & slave indexes */
+ th = qmt_trans_start_with_slv(env, lqe, slv_obj, &qti->qti_restore);
+ if (IS_ERR(th))
+ GOTO(out, rc = PTR_ERR(th));
+
+ lqe_write_lock(lqe);
+ LQUOTA_DEBUG(lqe, "dqacq starts uuid:%s flags:0x%x wanted:"LPU64
+ " usage:"LPU64, obd_uuid2str(uuid), qb_flags, qb_count,
+ qb_usage);
+
+ /* Legal race, limits have been removed on master, but slave didn't
+ * receive the change yet. Just return EINPROGRESS until the slave gets
+ * notified. */
+ if (!lqe->lqe_enforced && !req_is_rel(qb_flags))
+ GOTO(out_locked, rc = -EINPROGRESS);
+
+ /* recompute qunit in case it was never initialized */
+ qmt_revalidate(env, lqe);
+
+ /* slave just wants to acquire per-ID lock */
+ if (req_is_acq(qb_flags) && qb_count == 0)
+ GOTO(out_locked, rc = 0);
+
+ /* fetch how much quota space is already granted to this slave */
+ rc = qmt_slv_read(env, lqe, slv_obj, &slv_granted);
+ if (rc) {
+ LQUOTA_ERROR(lqe, "Failed to get granted for slave %s, rc=%d",
+ obd_uuid2str(uuid), rc);
+ GOTO(out_locked, rc);
+ }
+ /* recall how much space this slave currently owns in order to restore
+ * it in case of failure */
+ slv_granted_bck = slv_granted;
+
+ /* record current time for soft limit & grace time management */
+ now = (__u64)cfs_time_current_sec();
+
+ if (req_is_rel(qb_flags)) {
+ /* Slave would like to release quota space */
+ if (slv_granted < qb_count ||
+ lqe->lqe_granted < qb_count) {
+ /* can't release more than granted */
+ LQUOTA_ERROR(lqe, "Release too much! uuid:%s release:"
+ LPU64" granted:"LPU64", total:"LPU64,
+ obd_uuid2str(uuid), qb_count,
+ slv_granted, lqe->lqe_granted);
+ GOTO(out_locked, rc = -EINVAL);
+ }
+
+ repbody->qb_count = qb_count;
+ /* put released space back to global pool */
+ QMT_REL(lqe, slv_granted, qb_count);
+ GOTO(out_write, rc = 0);
+ }
+
+ if (req_has_rep(qb_flags) && slv_granted < qb_usage) {
+ /* Slave is reporting space usage in quota request and it turns
+ * out to be using more quota space than owned, so we adjust
+ * granted space regardless of the current state of affairs */
+ repbody->qb_count = qb_usage - slv_granted;
+ QMT_GRANT(lqe, slv_granted, repbody->qb_count);
+ }
+
+ if (!req_is_acq(qb_flags) && !req_is_preacq(qb_flags))
+ GOTO(out_write, rc = 0);
+
+ qmt_adjust_edquot(lqe, now);
+ if (lqe->lqe_edquot)
+ /* no hope to claim further space back */
+ GOTO(out_write, rc = -EDQUOT);
+
+ if (qmt_space_exhausted(lqe, now)) {
+ /* might have some free space once rebalancing is completed */
+ rc = req_is_acq(qb_flags) ? -EINPROGRESS : -EDQUOT;
+ GOTO(out_write, rc);
+ }
+
+ if (req_is_preacq(qb_flags)) {
+ /* slave would like to pre-acquire quota space. To do so, it
+ * reports in qb_count how much spare quota space it owns and we
+ * can grant back quota space which is consistent with qunit
+ * value. */
+
+ if (qb_count >= lqe->lqe_qunit)
+ /* slave already own the maximum it should */
+ GOTO(out_write, rc = 0);
+
+ count = qmt_alloc_expand(lqe, slv_granted, qb_count);
+ if (count == 0)
+ GOTO(out_write, rc = -EDQUOT);
+
+ repbody->qb_count += count;
+ QMT_GRANT(lqe, slv_granted, count);
+ GOTO(out_write, rc = 0);
+ }
+
+ /* processing acquire request with clients waiting */
+ if (lqe->lqe_hardlimit != 0 &&
+ lqe->lqe_granted + qb_count > lqe->lqe_hardlimit) {
+ /* cannot grant as much as asked, but can still afford to grant
+ * some quota space back */
+ count = lqe->lqe_hardlimit - lqe->lqe_granted;
+ repbody->qb_count += count;
+ QMT_GRANT(lqe, slv_granted, count);
+ GOTO(out_write, rc = 0);
+ }
+
+ /* Whouhou! we can satisfy the slave request! */
+ repbody->qb_count += qb_count;
+ QMT_GRANT(lqe, slv_granted, qb_count);
+
+ /* Try to expand the acquired count for DQACQ */
+ count = qmt_alloc_expand(lqe, slv_granted, 0);
+ if (count != 0) {
+ /* can even grant more than asked, it is like xmas ... */
+ repbody->qb_count += count;
+ QMT_GRANT(lqe, slv_granted, count);
+ GOTO(out_write, rc = 0);
+ }
+
+ GOTO(out_write, rc = 0);
+out_write:
+ if (repbody->qb_count == 0)
+ GOTO(out_locked, rc);
+
+ /* start/stop grace timer if required */
+ if (lqe->lqe_softlimit != 0) {
+ if (lqe->lqe_granted > lqe->lqe_softlimit &&
+ lqe->lqe_gracetime == 0)
+ /* first time over soft limit, let's start grace
+ * timer */
+ lqe->lqe_gracetime = now + qmt_lqe_grace(lqe);
+ else if (lqe->lqe_granted <= lqe->lqe_softlimit &&
+ lqe->lqe_gracetime != 0)
+ /* Clear grace timer */
+ lqe->lqe_gracetime = 0;
+ }
+
+ /* Update slave index first since it is easier to roll back */
+ ret = qmt_slv_write(env, th, lqe, slv_obj, LQUOTA_BUMP_VER,
+ &repbody->qb_slv_ver, slv_granted);
+ if (ret) {
+ /* restore initial quota settings */
+ qmt_restore(lqe, &qti->qti_restore);
+ /* reset qb_count */
+ repbody->qb_count = 0;
+ GOTO(out_locked, rc = ret);
+ }
+
+ /* Update global index, no version bump needed */
+ ret = qmt_glb_write(env, th, lqe, 0, NULL);
+ if (ret) {
+ rc = ret;
+ /* restore initial quota settings */
+ qmt_restore(lqe, &qti->qti_restore);
+ /* reset qb_count */
+ repbody->qb_count = 0;
+
+ /* restore previous granted value */
+ ret = qmt_slv_write(env, th, lqe, slv_obj, 0, NULL,
+ slv_granted_bck);
+ if (ret) {
+ LQUOTA_ERROR(lqe, "failed to restore initial slave "
+ "value rc:%d ret%d", rc, ret);
+ LBUG();
+ }
+ qmt_adjust_edquot(lqe, now);
+ GOTO(out_locked, rc);
+ }
+
+ /* Total granted has been changed, let's try to adjust the qunit
+ * size according to the total granted & limits. */
+ qmt_adjust_qunit(env, lqe);
+
+ /* clear/set edquot flag and notify slaves via glimpse if needed */
+ qmt_adjust_edquot(lqe, now);
+out_locked:
+ LQUOTA_DEBUG(lqe, "dqacq ends count:"LPU64" ver:"LPU64" rc:%d",
+ repbody->qb_count, repbody->qb_slv_ver, rc);
+ lqe_write_unlock(lqe);
+out:
+ if (th != NULL && !IS_ERR(th))
+ dt_trans_stop(env, qmt->qmt_child, th);
+
+ if (slv_obj != NULL && !IS_ERR(slv_obj))
+ lu_object_put(env, &slv_obj->do_lu);
+
+ if ((req_is_acq(qb_flags) || req_is_preacq(qb_flags)) &&
+ OBD_FAIL_CHECK(OBD_FAIL_QUOTA_EDQUOT)) {
+ /* introduce inconsistency between granted value in slave index
+ * and slave index copy of slave */
+ repbody->qb_count = 0;
+ rc = -EDQUOT;
+ }
+
+ RETURN(rc);
+}
+
+/*
git://git.whamcloud.com / fs / lustre-release.git / commitdiff