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LU-12758 quota: clear default flag for new ID
[fs/lustre-release.git] / lustre / quota / qmt_handler.c
index 19e706f..9d2a4cc 100644 (file)
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2012 Intel, Inc.
+ * Copyright (c) 2012, 2017, Intel Corporation.
  * Use is subject to license terms.
  *
  * Author: Johann Lombardi <johann.lombardi@intel.com>
  * Author: Niu    Yawei    <yawei.niu@intel.com>
  */
 
-#ifndef EXPORT_SYMTAB
-# define EXPORT_SYMTAB
-#endif
-
 #define DEBUG_SUBSYSTEM S_LQUOTA
 
 #include <obd_class.h>
 #include "qmt_internal.h"
 
 /*
- * Fetch grace time for either inode or block.
+ * Retrieve quota settings for a given identifier.
  *
  * \param env     - is the environment passed by the caller
  * \param qmt     - is the quota master target
- * \param pool_id - is the 16-bit pool identifier
  * \param restype - is the pool type, either block (i.e. LQUOTA_RES_DT) or inode
  *                  (i.e. LQUOTA_RES_MD)
  * \param qtype   - is the quota type
+ * \param id      - is the quota indentifier for which we want to acces quota
+ *                  settings.
+ * \param hard    - is the output variable where to copy the hard limit
+ * \param soft    - is the output variable where to copy the soft limit
  * \param time    - is the output variable where to copy the grace time
  */
-static int qmt_getinfo(const struct lu_env *env, struct qmt_device *qmt,
-                      __u16 pool_id, __u8 restype, __u8 qtype, __u64 *time)
+static int qmt_get(const struct lu_env *env, struct qmt_device *qmt,
+                  __u8 restype, __u8 qtype, union lquota_id *id,
+                  __u64 *hard, __u64 *soft, __u64 *time, bool is_default)
 {
-       struct qmt_thread_info  *qti = qmt_info(env);
-       union lquota_id         *id  = &qti->qti_id_bis;
        struct lquota_entry     *lqe;
        ENTRY;
 
-       /* Global grace time is stored in quota settings of ID 0. */
-       id->qid_uid = 0;
+       LASSERT(!is_default || id->qid_uid == 0);
 
-       /* look-up quota entry storing grace time */
-       lqe = qmt_pool_lqe_lookup(env, qmt, pool_id, restype, qtype, id);
+       /* look-up lqe structure containing quota settings */
+       lqe = qmt_pool_lqe_lookup(env, qmt, restype, qtype, id);
        if (IS_ERR(lqe))
                RETURN(PTR_ERR(lqe));
 
+       /* copy quota settings */
        lqe_read_lock(lqe);
-       LQUOTA_DEBUG(lqe, "getinfo");
-       /* copy grace time */
-       *time = lqe->lqe_gracetime;
+       LQUOTA_DEBUG(lqe, "fetch settings");
+       if (hard != NULL)
+               *hard = lqe->lqe_hardlimit;
+       if (soft != NULL)
+               *soft = lqe->lqe_softlimit;
+       if (time != NULL) {
+               *time = lqe->lqe_gracetime;
+               if (lqe->lqe_is_default)
+                       *time |= (__u64)LQUOTA_FLAG_DEFAULT <<
+                                                       LQUOTA_GRACE_BITS;
+       }
        lqe_read_unlock(lqe);
 
        lqe_putref(lqe);
        RETURN(0);
 }
 
-/*
- * Update grace time for either inode or block.
- * Global grace time is stored in quota settings of ID 0.
- *
- * \param env     - is the environment passed by the caller
- * \param qmt     - is the quota master target
- * \param pool_id - is the 16-bit pool identifier
- * \param restype - is the pool type, either block (i.e. LQUOTA_RES_DT) or inode
- *                  (i.e. LQUOTA_RES_MD)
- * \param qtype   - is the quota type
- * \param time    - is the new grace time
- */
-static int qmt_setinfo(const struct lu_env *env, struct qmt_device *qmt,
-                      __u16 pool_id, __u8 restype, __u8 qtype, __u64 time)
-{
-       struct qmt_thread_info  *qti = qmt_info(env);
-       union lquota_id         *id  = &qti->qti_id_bis;
-       struct lquota_entry     *lqe;
-       struct thandle          *th = NULL;
-       int                      rc;
-       ENTRY;
-
-       /* Global grace time is stored in quota settings of ID 0. */
-       id->qid_uid = 0;
-
-       /* look-up quota entry storing the global grace time */
-       lqe = qmt_pool_lqe_lookup(env, qmt, pool_id, restype, qtype, id);
-       if (IS_ERR(lqe))
-               RETURN(PTR_ERR(lqe));
-
-       /* allocate & start transaction with enough credits to update grace
-        * time in the global index file */
-       th = qmt_trans_start(env, lqe, &qti->qti_restore);
-       if (IS_ERR(th))
-               GOTO(out_nolock, rc = PTR_ERR(th));
-
-       /* write lock quota entry storing the grace time */
-       lqe_write_lock(lqe);
-       if (lqe->lqe_gracetime == time)
-               /* grace time is the same */
-               GOTO(out, rc = 0);
-
-       LQUOTA_DEBUG(lqe, "setinfo time:"LPU64, time);
-
-       /* set new grace time */
-       lqe->lqe_gracetime = time;
-       /* always set enforced bit for ID 0 to make sure it does not go away */
-       lqe->lqe_enforced  = true;
-
-       /* write new grace time to disk, no need for version bump */
-       rc = qmt_glb_write(env, th, lqe, 0, NULL);
-       if (rc) {
-               /* restore initial grace time */
-               qmt_restore(lqe, &qti->qti_restore);
-               GOTO(out, rc);
-       }
-       EXIT;
-out:
-       lqe_write_unlock(lqe);
-out_nolock:
-       lqe_putref(lqe);
-       if (th != NULL && !IS_ERR(th))
-               dt_trans_stop(env, qmt->qmt_child, th);
-       return rc;
-}
+struct qmt_entry_iter_data {
+       const struct lu_env *qeid_env;
+       struct qmt_device   *qeid_qmt;
+};
 
-/*
- * Retrieve quota settings for a given identifier.
- *
- * \param env     - is the environment passed by the caller
- * \param qmt     - is the quota master target
- * \param pool_id - is the 16-bit pool identifier
- * \param restype - is the pool type, either block (i.e. LQUOTA_RES_DT) or inode
- *                  (i.e. LQUOTA_RES_MD)
- * \param qtype   - is the quota type
- * \param id      - is the quota indentifier for which we want to acces quota
- *                  settings.
- * \param hard    - is the output variable where to copy the hard limit
- * \param soft    - is the output variable where to copy the soft limit
- * \param time    - is the output variable where to copy the grace time
- */
-static int qmt_getquota(const struct lu_env *env, struct qmt_device *qmt,
-                       __u16 pool_id, __u8 restype, __u8 qtype,
-                       union lquota_id *id, __u64 *hard, __u64 *soft,
-                       __u64 *time)
+static int qmt_entry_iter_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
+                            struct hlist_node *hnode, void *d)
 {
+       struct qmt_entry_iter_data *iter = (struct qmt_entry_iter_data *)d;
        struct lquota_entry     *lqe;
-       ENTRY;
 
-       /* look-up lqe structure containing quota settings */
-       lqe = qmt_pool_lqe_lookup(env, qmt, pool_id, restype, qtype, id);
-       if (IS_ERR(lqe))
-               RETURN(PTR_ERR(lqe));
+       lqe = hlist_entry(hnode, struct lquota_entry, lqe_hash);
+       LASSERT(atomic_read(&lqe->lqe_ref) > 0);
 
-       /* copy quota settings */
-       lqe_read_lock(lqe);
-       LQUOTA_DEBUG(lqe, "getquota");
-       *hard = lqe->lqe_hardlimit;
-       *soft = lqe->lqe_softlimit;
-       *time = lqe->lqe_gracetime;
-       lqe_read_unlock(lqe);
+       if (lqe->lqe_id.qid_uid == 0 || !lqe->lqe_is_default)
+               return 0;
 
-       lqe_putref(lqe);
-       RETURN(0);
+       return qmt_set_with_lqe(iter->qeid_env, iter->qeid_qmt, lqe, 0, 0, 0, 0,
+                               true, true);
 }
 
 /*
- * Update quota settings for a given identifier.
+ * Update quota settings for a given lqe.
  *
- * \param env     - is the environment passed by the caller
- * \param qmt     - is the quota master target
- * \param pool_id - is the 16-bit pool identifier
- * \param restype - is the pool type, either block (i.e. LQUOTA_RES_DT) or inode
- *                  (i.e. LQUOTA_RES_MD)
- * \param qtype   - is the quota type
- * \param id      - is the quota indentifier for which we want to modify quota
- *                  settings.
- * \param hard    - is the new hard limit
- * \param soft    - is the new soft limit
- * \param time    - is the new grace time
- * \param valid   - is the list of settings to change
+ * \param env        - is the environment passed by the caller
+ * \param qmt        - is the quota master target
+ * \param lqe        - is the lquota_entry for which we want to modify quota
+ *                     settings.
+ * \param hard       - is the new hard limit
+ * \param soft       - is the new soft limit
+ * \param time       - is the new grace time
+ * \param valid      - is the list of settings to change
+ * \param is_default - true for default quota setting
+ * \param is_updated - true if the lqe is updated and no need to write back
  */
-static int qmt_setquota(const struct lu_env *env, struct qmt_device *qmt,
-                       __u16 pool_id, __u8 restype, __u8 qtype,
-                       union lquota_id *id, __u64 hard, __u64 soft, __u64 time,
-                       __u32 valid)
+
+int qmt_set_with_lqe(const struct lu_env *env, struct qmt_device *qmt,
+                    struct lquota_entry *lqe, __u64 hard, __u64 soft,
+                    __u64 time, __u32 valid, bool is_default, bool is_updated)
 {
        struct qmt_thread_info  *qti = qmt_info(env);
-       struct lquota_entry     *lqe;
        struct thandle          *th = NULL;
-       __u64                    grace, ver;
-       bool                     dirtied = false, bump_version = false;
+       time64_t now;
+       __u64                    ver;
+       bool                     dirtied = false;
        int                      rc = 0;
        ENTRY;
 
-       /* fetch global grace time */
-       rc = qmt_getinfo(env, qmt, pool_id, restype, qtype, &grace);
-       if (rc)
-               RETURN(rc);
-
-       /* look-up quota entry associated with this ID */
-       lqe = qmt_pool_lqe_lookup(env, qmt, pool_id, restype, qtype, id);
-       if (IS_ERR(lqe))
-               RETURN(PTR_ERR(lqe));
+       /* need to write back to global quota file? */
+       if (!is_updated) {
+               /* allocate & start transaction with enough credits to update
+                * quota  settings in the global index file */
+               th = qmt_trans_start(env, lqe, &qti->qti_restore);
+               if (IS_ERR(th))
+                       GOTO(out_nolock, rc = PTR_ERR(th));
+       }
 
-       /* allocate & start transaction with enough credits to update quota
-        * settings in the global index file */
-       th = qmt_trans_start(env, lqe, &qti->qti_restore);
-       if (IS_ERR(th))
-               GOTO(out_nolock, rc = PTR_ERR(th));
+       now = ktime_get_real_seconds();
 
        lqe_write_lock(lqe);
-       LQUOTA_DEBUG(lqe, "setquota valid:%x hard:"LPU64" soft:"LPU64
-                    " time:"LPU64, valid, hard, soft, time);
+       LQUOTA_DEBUG(lqe, "changing quota settings valid:%x hard:%llu soft:"
+                    "%llu time:%llu", valid, hard, soft, time);
+
+       if (is_default && lqe->lqe_id.qid_uid != 0) {
+               LQUOTA_DEBUG(lqe, "set qid %llu to use default quota setting",
+                            lqe->lqe_id.qid_uid);
+
+               qmt_lqe_set_default(env, lqe->lqe_site->lqs_parent, lqe, false);
+               GOTO(quota_set, 0);
+       }
 
        if ((valid & QIF_TIMES) != 0 && lqe->lqe_gracetime != time) {
                /* change time settings */
@@ -237,8 +159,6 @@ static int qmt_setquota(const struct lu_env *env, struct qmt_device *qmt,
 
        if ((valid & QIF_LIMITS) != 0 &&
            (lqe->lqe_hardlimit != hard || lqe->lqe_softlimit != soft)) {
-               bool enforced = lqe->lqe_enforced;
-
                rc = qmt_validate_limits(lqe, hard, soft);
                if (rc)
                        GOTO(out, rc);
@@ -247,6 +167,10 @@ static int qmt_setquota(const struct lu_env *env, struct qmt_device *qmt,
                lqe->lqe_hardlimit = hard;
                lqe->lqe_softlimit = soft;
 
+quota_set:
+               /* recompute qunit in case it was never initialized */
+               qmt_revalidate(env, lqe);
+
                /* clear grace time */
                if (lqe->lqe_softlimit == 0 ||
                    lqe->lqe_granted <= lqe->lqe_softlimit)
@@ -255,46 +179,110 @@ static int qmt_setquota(const struct lu_env *env, struct qmt_device *qmt,
                        lqe->lqe_gracetime = 0;
                else if ((valid & QIF_TIMES) == 0)
                        /* set grace only if user hasn't provided his own */
-                        lqe->lqe_gracetime = cfs_time_current_sec() + grace;
+                        lqe->lqe_gracetime = now + qmt_lqe_grace(lqe);
 
                /* change enforced status based on new parameters */
-               if (lqe->lqe_hardlimit == 0 && lqe->lqe_softlimit == 0)
+               if (lqe->lqe_id.qid_uid == 0 || (lqe->lqe_hardlimit == 0 &&
+                   lqe->lqe_softlimit == 0))
                        lqe->lqe_enforced = false;
                else
                        lqe->lqe_enforced = true;
 
-               if ((enforced && !lqe->lqe_enforced) ||
-                   (!enforced && lqe->lqe_enforced))
-                       /* if enforced status has changed, we need to inform
-                        * slave, therefore we need to bump the version */
-                        bump_version = true;
+               dirtied = true;
+       }
+
+       if (!is_default && lqe->lqe_is_default) {
+               LQUOTA_DEBUG(lqe, "the qid %llu has been set quota"
+                            " explicitly, clear the default flag",
+                            lqe->lqe_id.qid_uid);
 
+               qmt_lqe_clear_default(lqe);
                dirtied = true;
        }
 
        if (dirtied) {
-               /* write new quota settings to disk */
-               rc = qmt_glb_write(env, th, lqe,
-                                  bump_version ? LQUOTA_BUMP_VER : 0, &ver);
-               if (rc) {
-                       /* restore initial quota settings */
-                       qmt_restore(lqe, &qti->qti_restore);
-                       GOTO(out, rc);
+               if (!is_updated) {
+                       /* write new quota settings to disk */
+                       rc = qmt_glb_write(env, th, lqe, LQUOTA_BUMP_VER, &ver);
+                       if (rc) {
+                               /* restore initial quota settings */
+                               qmt_restore(lqe, &qti->qti_restore);
+                               GOTO(out, rc);
+                       }
+               } else {
+                       ver = dt_version_get(env, LQE_GLB_OBJ(lqe));
                }
+
+               /* compute new qunit value now that we have modified the quota
+                * settings */
+               qmt_adjust_qunit(env, lqe);
+
+               /* clear/set edquot flag as needed */
+               qmt_adjust_edquot(lqe, now);
        }
        EXIT;
 out:
        lqe_write_unlock(lqe);
-out_nolock:
-       lqe_putref(lqe);
 
+out_nolock:
        if (th != NULL && !IS_ERR(th))
                dt_trans_stop(env, qmt->qmt_child, th);
 
+       if (rc == 0 && dirtied) {
+               qmt_glb_lock_notify(env, lqe, ver);
+               if (lqe->lqe_id.qid_uid == 0) {
+                       struct qmt_entry_iter_data iter_data;
+
+                       LQUOTA_DEBUG(lqe, "notify all lqe with default quota");
+                       iter_data.qeid_env = env;
+                       iter_data.qeid_qmt = qmt;
+                       cfs_hash_for_each_safe(lqe->lqe_site->lqs_hash,
+                                              qmt_entry_iter_cb, &iter_data);
+               }
+       }
+
        return rc;
 }
 
 /*
+ * Update quota settings for a given identifier.
+ *
+ * \param env        - is the environment passed by the caller
+ * \param qmt        - is the quota master target
+ * \param restype    - is the pool type, either block (i.e. LQUOTA_RES_DT) or
+ *                     inode (i.e. LQUOTA_RES_MD)
+ * \param qtype      - is the quota type
+ * \param id         - is the quota indentifier for which we want to modify
+ *                     quota settings.
+ * \param hard       - is the new hard limit
+ * \param soft       - is the new soft limit
+ * \param time       - is the new grace time
+ * \param valid      - is the list of settings to change
+ * \param is_default - true for default quota setting
+ * \param is_updated - true if the lqe is updated and no need to write back
+ */
+static int qmt_set(const struct lu_env *env, struct qmt_device *qmt,
+                  __u8 restype, __u8 qtype, union lquota_id *id,
+                  __u64 hard, __u64 soft, __u64 time, __u32 valid,
+                  bool is_default, bool is_updated)
+{
+       struct lquota_entry *lqe;
+       int rc;
+       ENTRY;
+
+       /* look-up quota entry associated with this ID */
+       lqe = qmt_pool_lqe_lookup(env, qmt, restype, qtype, id);
+       if (IS_ERR(lqe))
+                       RETURN(PTR_ERR(lqe));
+
+       rc = qmt_set_with_lqe(env, qmt, lqe, hard, soft, time, valid,
+                             is_default, is_updated);
+
+       lqe_putref(lqe);
+       RETURN(rc);
+}
+
+/*
  * Handle quotactl request.
  *
  * \param env   - is the environment passed by the caller
@@ -309,62 +297,68 @@ static int qmt_quotactl(const struct lu_env *env, struct lu_device *ld,
        struct qmt_device       *qmt = lu2qmt_dev(ld);
        struct obd_dqblk        *dqb = &oqctl->qc_dqblk;
        int                      rc = 0;
+       bool                     is_default = false;
        ENTRY;
 
        LASSERT(qmt != NULL);
 
-       if (oqctl->qc_type >= MAXQUOTAS)
+       if (oqctl->qc_type >= LL_MAXQUOTAS)
                /* invalid quota type */
                RETURN(-EINVAL);
 
        switch (oqctl->qc_cmd) {
 
        case Q_GETINFO:  /* read grace times */
+               /* Global grace time is stored in quota settings of ID 0. */
+               id->qid_uid = 0;
+
                /* read inode grace time */
-               rc = qmt_getinfo(env, qmt, 0, LQUOTA_RES_MD, oqctl->qc_type,
-                                &oqctl->qc_dqinfo.dqi_igrace);
+               rc = qmt_get(env, qmt, LQUOTA_RES_MD, oqctl->qc_type, id,
+                            NULL, NULL, &oqctl->qc_dqinfo.dqi_igrace, false);
                if (rc)
                        break;
 
                /* read block grace time */
-               rc = qmt_getinfo(env, qmt, 0, LQUOTA_RES_DT, oqctl->qc_type,
-                                &oqctl->qc_dqinfo.dqi_bgrace);
+               rc = qmt_get(env, qmt, LQUOTA_RES_DT, oqctl->qc_type, id,
+                            NULL, NULL, &oqctl->qc_dqinfo.dqi_bgrace, false);
                break;
 
        case Q_SETINFO:  /* modify grace times */
                /* setinfo should be using dqi->dqi_valid, but lfs incorrectly
                 * sets the valid flags in dqb->dqb_valid instead, try to live
                 * with that ... */
+
+               /* Global grace time is stored in quota settings of ID 0. */
+               id->qid_uid = 0;
+
                if ((dqb->dqb_valid & QIF_ITIME) != 0) {
                        /* set inode grace time */
-                       rc = qmt_setinfo(env, qmt, 0, LQUOTA_RES_MD,
-                                        oqctl->qc_type,
-                                        oqctl->qc_dqinfo.dqi_igrace);
+                       rc = qmt_set(env, qmt, LQUOTA_RES_MD, oqctl->qc_type,
+                                    id, 0, 0, oqctl->qc_dqinfo.dqi_igrace,
+                                    QIF_TIMES, false, false);
                        if (rc)
                                break;
                }
 
                if ((dqb->dqb_valid & QIF_BTIME) != 0)
                        /* set block grace time */
-                       rc = qmt_setinfo(env, qmt, 0, LQUOTA_RES_DT,
-                                        oqctl->qc_type,
-                                        oqctl->qc_dqinfo.dqi_bgrace);
+                       rc = qmt_set(env, qmt, LQUOTA_RES_DT, oqctl->qc_type,
+                                    id, 0, 0, oqctl->qc_dqinfo.dqi_bgrace,
+                                    QIF_TIMES, false, false);
                break;
 
+       case LUSTRE_Q_GETDEFAULT:
+               is_default = true;
+               /* fallthrough */
+
        case Q_GETQUOTA: /* consult quota limit */
-               /* There is no quota limit for root user & group */
-               if (oqctl->qc_id == 0) {
-                       memset(dqb, 0, sizeof(*dqb));
-                       dqb->dqb_valid = QIF_LIMITS | QIF_TIMES;
-                       break;
-               }
                /* extract quota ID from quotactl request */
                id->qid_uid = oqctl->qc_id;
 
                /* look-up inode quota settings */
-               rc = qmt_getquota(env, qmt, 0, LQUOTA_RES_MD, oqctl->qc_type,
-                                 id, &dqb->dqb_ihardlimit,
-                                 &dqb->dqb_isoftlimit, &dqb->dqb_itime);
+               rc = qmt_get(env, qmt, LQUOTA_RES_MD, oqctl->qc_type, id,
+                            &dqb->dqb_ihardlimit, &dqb->dqb_isoftlimit,
+                            &dqb->dqb_itime, is_default);
                if (rc)
                        break;
 
@@ -373,9 +367,9 @@ static int qmt_quotactl(const struct lu_env *env, struct lu_device *ld,
                dqb->dqb_curinodes = 0;
 
                /* look-up block quota settings */
-               rc = qmt_getquota(env, qmt, 0, LQUOTA_RES_DT, oqctl->qc_type,
-                                 id, &dqb->dqb_bhardlimit,
-                                 &dqb->dqb_bsoftlimit, &dqb->dqb_btime);
+               rc = qmt_get(env, qmt, LQUOTA_RES_DT, oqctl->qc_type, id,
+                            &dqb->dqb_bhardlimit, &dqb->dqb_bsoftlimit,
+                            &dqb->dqb_btime, is_default);
                if (rc)
                        break;
 
@@ -384,40 +378,34 @@ static int qmt_quotactl(const struct lu_env *env, struct lu_device *ld,
                dqb->dqb_curspace = 0;
                break;
 
+       case LUSTRE_Q_SETDEFAULT:
+               is_default = true;
+               /* fallthrough */
+
        case Q_SETQUOTA: /* change quota limits */
-               if (oqctl->qc_id == 0)
-                       /* can't enforce a quota limit for root user & group */
-                       RETURN(-EPERM);
                /* extract quota ID from quotactl request */
                id->qid_uid = oqctl->qc_id;
 
                if ((dqb->dqb_valid & QIF_IFLAGS) != 0) {
                        /* update inode quota settings */
-                       rc = qmt_setquota(env, qmt, 0, LQUOTA_RES_MD,
-                                         oqctl->qc_type, id,
-                                         dqb->dqb_ihardlimit,
-                                         dqb->dqb_isoftlimit, dqb->dqb_itime,
-                                         dqb->dqb_valid & QIF_IFLAGS);
+                       rc = qmt_set(env, qmt, LQUOTA_RES_MD, oqctl->qc_type,
+                                    id, dqb->dqb_ihardlimit,
+                                    dqb->dqb_isoftlimit, dqb->dqb_itime,
+                                    dqb->dqb_valid & QIF_IFLAGS, is_default,
+                                    false);
                        if (rc)
                                break;
                }
 
                if ((dqb->dqb_valid & QIF_BFLAGS) != 0)
                        /* update block quota settings */
-                       rc = qmt_setquota(env, qmt, 0, LQUOTA_RES_DT,
-                                         oqctl->qc_type, id,
-                                         dqb->dqb_bhardlimit,
-                                         dqb->dqb_bsoftlimit, dqb->dqb_btime,
-                                         dqb->dqb_valid & QIF_BFLAGS);
+                       rc = qmt_set(env, qmt, LQUOTA_RES_DT, oqctl->qc_type,
+                                    id, dqb->dqb_bhardlimit,
+                                    dqb->dqb_bsoftlimit, dqb->dqb_btime,
+                                    dqb->dqb_valid & QIF_BFLAGS, is_default,
+                                    false);
                break;
 
-       case Q_QUOTAON:
-       case Q_QUOTAOFF:   /* quota is always turned on on the master */
-               RETURN(0);
-
-       case LUSTRE_Q_INVALIDATE: /* not supported any more */
-               RETURN(-ENOTSUPP);
-
        default:
                CERROR("%s: unsupported quotactl command: %d\n",
                       qmt->qmt_svname, oqctl->qc_cmd);
@@ -428,6 +416,255 @@ static int qmt_quotactl(const struct lu_env *env, struct lu_device *ld,
 }
 
 /*
+ * 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:%llu"
+                    " usage:%llu", 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 = -ESRCH);
+
+       /* 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 = ktime_get_real_seconds();
+
+       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:"
+                                    "%llu granted:%llu, total:%llu",
+                                    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:%llu ver:%llu 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))
+               dt_object_put(env, slv_obj);
+
+       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);
+}
+
+/*
  * Handle quota request from slave.
  *
  * \param env  - is the environment passed by the caller
@@ -437,7 +674,13 @@ static int qmt_quotactl(const struct lu_env *env, struct lu_device *ld,
 static int qmt_dqacq(const struct lu_env *env, struct lu_device *ld,
                     struct ptlrpc_request *req)
 {
+       struct qmt_device       *qmt = lu2qmt_dev(ld);
        struct quota_body       *qbody, *repbody;
+       struct obd_uuid         *uuid;
+       struct ldlm_lock        *lock;
+       struct lquota_entry     *lqe;
+       int                      pool_type, qtype;
+       int                      rc;
        ENTRY;
 
        qbody = req_capsule_client_get(&req->rq_pill, &RMF_QUOTA_BODY);
@@ -448,9 +691,82 @@ static int qmt_dqacq(const struct lu_env *env, struct lu_device *ld,
        if (repbody == NULL)
                RETURN(err_serious(-EFAULT));
 
-       /* XXX: to be implemented */
+       /* verify if global lock is stale */
+       if (!lustre_handle_is_used(&qbody->qb_glb_lockh))
+               RETURN(-ENOLCK);
 
-       RETURN(0);
+       lock = ldlm_handle2lock(&qbody->qb_glb_lockh);
+       if (lock == NULL)
+               RETURN(-ENOLCK);
+       LDLM_LOCK_PUT(lock);
+
+       uuid = &req->rq_export->exp_client_uuid;
+
+       if (req_is_rel(qbody->qb_flags) + req_is_acq(qbody->qb_flags) +
+           req_is_preacq(qbody->qb_flags) > 1) {
+               CERROR("%s: malformed quota request with conflicting flags set "
+                      "(%x) from slave %s\n", qmt->qmt_svname,
+                      qbody->qb_flags, obd_uuid2str(uuid));
+               RETURN(-EPROTO);
+       }
+
+       if (req_is_acq(qbody->qb_flags) || req_is_preacq(qbody->qb_flags)) {
+               /* acquire and pre-acquire should use a valid ID lock */
+
+               if (!lustre_handle_is_used(&qbody->qb_lockh))
+                       RETURN(-ENOLCK);
+
+               lock = ldlm_handle2lock(&qbody->qb_lockh);
+               if (lock == NULL)
+                       /* no lock associated with this handle */
+                       RETURN(-ENOLCK);
+
+               LDLM_DEBUG(lock, "%sacquire request",
+                          req_is_preacq(qbody->qb_flags) ? "pre" : "");
+
+               if (!obd_uuid_equals(&lock->l_export->exp_client_uuid, uuid)) {
+                       /* sorry, no way to cheat ... */
+                       LDLM_LOCK_PUT(lock);
+                       RETURN(-ENOLCK);
+               }
+
+               if (ldlm_is_ast_sent(lock)) {
+                       struct ptlrpc_service_part *svc;
+                       time64_t timeout;
+
+                       svc = req->rq_rqbd->rqbd_svcpt;
+                       timeout = at_est2timeout(at_get(&svc->scp_at_estimate));
+                       timeout += (ldlm_bl_timeout(lock) >> 1);
+
+                       /* lock is being cancelled, prolong timeout */
+                       ldlm_refresh_waiting_lock(lock, timeout);
+               }
+               LDLM_LOCK_PUT(lock);
+       }
+
+       /* extract quota information from global index FID packed in the
+        * request */
+       rc = lquota_extract_fid(&qbody->qb_fid, &pool_type, &qtype);
+       if (rc)
+               RETURN(-EINVAL);
+
+       /* Find the quota entry associated with the quota id */
+       lqe = qmt_pool_lqe_lookup(env, qmt, pool_type, qtype,
+                                 &qbody->qb_id);
+       if (IS_ERR(lqe))
+               RETURN(PTR_ERR(lqe));
+
+       /* process quota request */
+       rc = qmt_dqacq0(env, lqe, qmt, uuid, qbody->qb_flags, qbody->qb_count,
+                       qbody->qb_usage, repbody);
+
+       if (lustre_handle_is_used(&qbody->qb_lockh))
+               /* return current qunit value only to slaves owning an per-ID
+                * quota lock. For enqueue, the qunit value will be returned in
+                * the LVB */
+                repbody->qb_qunit = lqe->lqe_qunit;
+       lqe_putref(lqe);
+       RETURN(rc);
 }
 
 /* Vector of quota request handlers. This vector is used by the MDT to forward