X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosp%2Fosp_precreate.c;h=805f87db95588fcf180cfed05dff7622bc796357;hp=cac5bf2bf350aba96878874fd401883c1b5857fc;hb=c807e3f33b39409a061fa997cac57ac394c503ba;hpb=2686b25c301f055a15d13f085f5184e6f5cbbe13

diff --git a/lustre/osp/osp_precreate.c b/lustre/osp/osp_precreate.c
index cac5bf2..805f87d 100644
--- a/lustre/osp/osp_precreate.c
+++ b/lustre/osp/osp_precreate.c
@@ -15,11 +15,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,13 +23,12 @@
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, 2014, Intel Corporation.
+ * Copyright (c) 2012, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
  *
- * lustre/osp/osp_sync.c
+ * lustre/osp/osp_precreate.c
  *
  * Lustre OST Proxy Device
  *
@@ -45,6 +40,9 @@
 #define DEBUG_SUBSYSTEM S_MDS
 
 #include <linux/kthread.h>
+
+#include <lustre_obdo.h>
+
 #include "osp_internal.h"
 
 /*
@@ -53,12 +51,11 @@
  * = import is disconnected =
  *
  * = import is inactive =
- *   in this case osp_declare_object_create() returns an error
+ *   in this case osp_declare_create() returns an error
  *
  */
 
-/*
- **
+/**
  * Check whether statfs data is expired
  *
  * OSP device caches statfs data for the target, the function checks
@@ -70,8 +67,7 @@
  */
 static inline int osp_statfs_need_update(struct osp_device *d)
 {
-	return !cfs_time_before(cfs_time_current(),
-				d->opd_statfs_fresh_till);
+	return !ktime_before(ktime_get(), d->opd_statfs_fresh_till);
 }
 
 /*
@@ -80,25 +76,46 @@ static inline int osp_statfs_need_update(struct osp_device *d)
  *
  * each time OSP gets connected to OST, we should start from precreation cleanup
  */
-static inline bool osp_precreate_running(struct osp_device *d)
+static void osp_statfs_timer_cb(cfs_timer_cb_arg_t data)
 {
-	return !!(d->opd_pre_thread.t_flags & SVC_RUNNING);
+	struct osp_device *d = cfs_from_timer(d, data, opd_statfs_timer);
+
+	LASSERT(d);
+	if (d->opd_pre_task)
+		wake_up(&d->opd_pre_waitq);
 }
 
-static inline bool osp_precreate_stopped(struct osp_device *d)
+static void osp_pre_update_msfs(struct osp_device *d, struct obd_statfs *msfs);
+
+/*
+ * The function updates current precreation status if broken, and
+ * updates that cached statfs state if functional, then wakes up waiters.
+ * We don't clear opd_pre_status directly here, but rather leave this
+ * to osp_pre_update_msfs() to do if everything is OK so that we don't
+ * have a race to clear opd_pre_status and then set it to -ENOSPC again.
+ *
+ * \param[in] d		OSP device
+ * \param[in] msfs	statfs data
+ * \param[in] rc	new precreate status for device \a d
+ */
+static void osp_pre_update_status_msfs(struct osp_device *d,
+				       struct obd_statfs *msfs, int rc)
 {
-	return !!(d->opd_pre_thread.t_flags & SVC_STOPPED);
+	if (rc)
+		d->opd_pre_status = rc;
+	else
+		osp_pre_update_msfs(d, msfs);
+
+	wake_up(&d->opd_pre_user_waitq);
 }
 
-static void osp_statfs_timer_cb(unsigned long _d)
+/* Pass in the old statfs data in case the limits have changed */
+void osp_pre_update_status(struct osp_device *d, int rc)
 {
-	struct osp_device *d = (struct osp_device *) _d;
-
-	LASSERT(d);
-	if (d->opd_pre != NULL && osp_precreate_running(d))
-		wake_up(&d->opd_pre_waitq);
+	osp_pre_update_status_msfs(d, &d->opd_statfs, rc);
 }
 
+
 /**
  * RPC interpret callback for OST_STATFS RPC
  *
@@ -116,16 +133,18 @@ static void osp_statfs_timer_cb(unsigned long _d)
  * \retval negative	negated errno on error
  */
 static int osp_statfs_interpret(const struct lu_env *env,
-				struct ptlrpc_request *req,
-				union ptlrpc_async_args *aa, int rc)
+				struct ptlrpc_request *req, void *args, int rc)
 {
-	struct obd_import	*imp = req->rq_import;
-	struct obd_statfs	*msfs;
-	struct osp_device	*d;
+	union ptlrpc_async_args *aa = args;
+	struct obd_import *imp = req->rq_import;
+	struct obd_statfs *msfs;
+	struct obd_statfs *sfs;
+	struct osp_device *d;
+	u64 maxage_ns;
 
 	ENTRY;
 
-	aa = ptlrpc_req_async_args(req);
+	aa = ptlrpc_req_async_args(aa, req);
 	d = aa->pointer_arg[0];
 	LASSERT(d);
 
@@ -136,21 +155,32 @@ static int osp_statfs_interpret(const struct lu_env *env,
 	if (msfs == NULL)
 		GOTO(out, rc = -EPROTO);
 
-	d->opd_statfs = *msfs;
-
-	osp_pre_update_status(d, rc);
+	if (d->opd_pre)
+		osp_pre_update_status_msfs(d, msfs, 0);
+	else
+		d->opd_statfs = *msfs;
 
 	/* schedule next update */
-	d->opd_statfs_fresh_till = cfs_time_shift(d->opd_statfs_maxage);
-	cfs_timer_arm(&d->opd_statfs_timer, d->opd_statfs_fresh_till);
+	maxage_ns = d->opd_statfs_maxage * NSEC_PER_SEC;
+	d->opd_statfs_fresh_till = ktime_add_ns(ktime_get(), maxage_ns);
+	mod_timer(&d->opd_statfs_timer,
+		  jiffies + cfs_time_seconds(d->opd_statfs_maxage));
 	d->opd_statfs_update_in_progress = 0;
 
-	CDEBUG(D_CACHE, "updated statfs %p\n", d);
+	sfs = &d->opd_statfs;
+	CDEBUG(D_CACHE, "%s (%p): %llu blocks, %llu free, %llu avail, "
+	       "%u bsize, %u reserved mb low, %u reserved mb high,"
+	       "%llu files, %llu free files\n", d->opd_obd->obd_name, d,
+	       sfs->os_blocks, sfs->os_bfree, sfs->os_bavail, sfs->os_bsize,
+	       d->opd_reserved_mb_low, d->opd_reserved_mb_high,
+	       sfs->os_files, sfs->os_ffree);
 
 	RETURN(0);
 out:
-	/* couldn't update statfs, try again as soon as possible */
-	if (d->opd_pre != NULL && osp_precreate_running(d))
+	/* couldn't update statfs, try again with a small delay */
+	d->opd_statfs_fresh_till = ktime_add_ns(ktime_get(), 10 * NSEC_PER_SEC);
+	d->opd_statfs_update_in_progress = 0;
+	if (d->opd_pre && d->opd_pre_task)
 		wake_up(&d->opd_pre_waitq);
 
 	if (req->rq_import_generation == imp->imp_generation)
@@ -169,12 +199,13 @@ out:
  *
  * \param[in] d		OSP device
  */
-static int osp_statfs_update(struct osp_device *d)
+static int osp_statfs_update(const struct lu_env *env, struct osp_device *d)
 {
+	u64 expire = obd_timeout * 1000 * NSEC_PER_SEC;
 	struct ptlrpc_request	*req;
 	struct obd_import	*imp;
 	union ptlrpc_async_args	*aa;
-	int			 rc;
+	int rc;
 
 	ENTRY;
 
@@ -183,32 +214,59 @@ static int osp_statfs_update(struct osp_device *d)
 	imp = d->opd_obd->u.cli.cl_import;
 	LASSERT(imp);
 
-	req = ptlrpc_request_alloc(imp, &RQF_OST_STATFS);
+	req = ptlrpc_request_alloc(imp,
+			   d->opd_pre ? &RQF_OST_STATFS : &RQF_MDS_STATFS);
 	if (req == NULL)
 		RETURN(-ENOMEM);
 
-	rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_STATFS);
+	rc = ptlrpc_request_pack(req,
+			 d->opd_pre ? LUSTRE_OST_VERSION : LUSTRE_MDS_VERSION,
+			 d->opd_pre ? OST_STATFS : MDS_STATFS);
 	if (rc) {
 		ptlrpc_request_free(req);
 		RETURN(rc);
 	}
 	ptlrpc_request_set_replen(req);
-	req->rq_request_portal = OST_CREATE_PORTAL;
+	if (d->opd_pre)
+		req->rq_request_portal = OST_CREATE_PORTAL;
 	ptlrpc_at_set_req_timeout(req);
 
-	req->rq_interpret_reply = (ptlrpc_interpterer_t)osp_statfs_interpret;
-	aa = ptlrpc_req_async_args(req);
+	req->rq_interpret_reply = osp_statfs_interpret;
+	aa = ptlrpc_req_async_args(aa, req);
 	aa->pointer_arg[0] = d;
 
 	/*
 	 * no updates till reply
 	 */
-	cfs_timer_disarm(&d->opd_statfs_timer);
-	d->opd_statfs_fresh_till = cfs_time_shift(obd_timeout * 1000);
+	del_timer(&d->opd_statfs_timer);
+	d->opd_statfs_fresh_till = ktime_add_ns(ktime_get(), expire);
 	d->opd_statfs_update_in_progress = 1;
 
 	ptlrpcd_add_req(req);
 
+	/* we still want to sync changes if no new changes are coming */
+	if (ktime_before(ktime_get(), d->opd_sync_next_commit_cb))
+		GOTO(out, rc);
+
+	if (atomic_read(&d->opd_sync_changes)) {
+		struct thandle *th;
+
+		th = dt_trans_create(env, d->opd_storage);
+		if (IS_ERR(th)) {
+			CERROR("%s: can't sync\n", d->opd_obd->obd_name);
+			GOTO(out, rc);
+		}
+		rc = dt_trans_start_local(env, d->opd_storage, th);
+		if (rc == 0) {
+			CDEBUG(D_OTHER, "%s: sync forced, %d changes\n",
+			       d->opd_obd->obd_name,
+			       atomic_read(&d->opd_sync_changes));
+			osp_sync_add_commit_cb_1s(env, d, th);
+		}
+		dt_trans_stop(env, d->opd_storage, th);
+	}
+
+out:
 	RETURN(0);
 }
 
@@ -233,8 +291,8 @@ void osp_statfs_need_now(struct osp_device *d)
 		 * then we should poll OST immediately once object destroy
 		 * is replied
 		 */
-		d->opd_statfs_fresh_till = cfs_time_shift(-1);
-		cfs_timer_disarm(&d->opd_statfs_timer);
+		d->opd_statfs_fresh_till = ktime_sub_ns(ktime_get(), NSEC_PER_SEC);
+		del_timer(&d->opd_statfs_timer);
 		wake_up(&d->opd_pre_waitq);
 	}
 }
@@ -277,7 +335,7 @@ static inline int osp_precreate_near_empty_nolock(const struct lu_env *env,
 
 	/* don't consider new precreation till OST is healty and
 	 * has free space */
-	return ((window - d->opd_pre_reserved < d->opd_pre_grow_count / 2) &&
+	return ((window - d->opd_pre_reserved < d->opd_pre_create_count / 2) &&
 		(d->opd_pre_status == 0));
 }
 
@@ -297,6 +355,9 @@ static inline int osp_precreate_near_empty(const struct lu_env *env,
 {
 	int rc;
 
+	if (d->opd_pre == NULL)
+		return 0;
+
 	/* XXX: do we really need locking here? */
 	spin_lock(&d->opd_pre_lock);
 	rc = osp_precreate_near_empty_nolock(env, d);
@@ -350,20 +411,23 @@ int osp_write_last_oid_seq_files(struct lu_env *env, struct osp_device *osp,
 	struct lu_buf	   *lb_oid = &oti->osi_lb;
 	struct lu_buf	   *lb_oseq = &oti->osi_lb2;
 	loff_t		   oid_off;
+	u64		   oid;
 	loff_t		   oseq_off;
 	struct thandle	  *th;
 	int		      rc;
 	ENTRY;
 
+	if (osp->opd_storage->dd_rdonly)
+		RETURN(0);
+
 	/* Note: through f_oid is only 32 bits, it will also write 64 bits
 	 * for oid to keep compatibility with the previous version. */
-	lb_oid->lb_buf = &fid->f_oid;
-	lb_oid->lb_len = sizeof(u64);
-	oid_off = sizeof(u64) * osp->opd_index;
+	oid = fid->f_oid;
+	osp_objid_buf_prep(lb_oid, &oid_off,
+			   &oid, osp->opd_index);
 
-	lb_oseq->lb_buf = &fid->f_seq;
-	lb_oseq->lb_len = sizeof(u64);
-	oseq_off = sizeof(u64) * osp->opd_index;
+	osp_objseq_buf_prep(lb_oseq, &oseq_off,
+			    &fid->f_seq, osp->opd_index);
 
 	th = dt_trans_create(env, osp->opd_storage);
 	if (IS_ERR(th))
@@ -450,12 +514,13 @@ static int osp_precreate_rollover_new_seq(struct lu_env *env,
 		RETURN(rc);
 	}
 
-	LCONSOLE_INFO("%s: update sequence from "LPX64" to "LPX64"\n",
+	LCONSOLE_INFO("%s: update sequence from %#llx to %#llx\n",
 		      osp->opd_obd->obd_name, fid_seq(last_fid),
 		      fid_seq(fid));
 	/* Update last_xxx to the new seq */
 	spin_lock(&osp->opd_pre_lock);
 	osp->opd_last_used_fid = *fid;
+	osp_fid_to_obdid(fid, &osp->opd_last_id);
 	osp->opd_gap_start_fid = *fid;
 	osp->opd_pre_used_fid = *fid;
 	osp->opd_pre_last_created_fid = *fid;
@@ -492,16 +557,17 @@ static int osp_precreate_fids(const struct lu_env *env, struct osp_device *osp,
 	if (fid_is_idif(fid)) {
 		struct lu_fid	*last_fid;
 		struct ost_id	*oi = &osi->osi_oi;
+		int rc;
 
 		spin_lock(&osp->opd_pre_lock);
 		last_fid = &osp->opd_pre_last_created_fid;
 		fid_to_ostid(last_fid, oi);
 		end = min(ostid_id(oi) + *grow, IDIF_MAX_OID);
 		*grow = end - ostid_id(oi);
-		ostid_set_id(oi, ostid_id(oi) + *grow);
+		rc = ostid_set_id(oi, ostid_id(oi) + *grow);
 		spin_unlock(&osp->opd_pre_lock);
 
-		if (*grow == 0)
+		if (*grow == 0 || rc)
 			return 1;
 
 		ostid_to_fid(fid, oi, osp->opd_index);
@@ -527,9 +593,9 @@ static int osp_precreate_fids(const struct lu_env *env, struct osp_device *osp,
  *
  * The function finds how many objects should be precreated.  Then allocates,
  * prepares and schedules precreate RPC synchronously. Upon reply the function
- * wake ups the threads waiting for the new objects on this target. If the
+ * wakes up the threads waiting for the new objects on this target. If the
  * target wasn't able to create all the objects requested, then the next
- * precreate will be asking less objects (i.e. slow precreate down).
+ * precreate will be asking for fewer objects (i.e. slow precreate down).
  *
  * \param[in] env	LU environment provided by the caller
  * \param[in] d		OSP device
@@ -575,9 +641,9 @@ static int osp_precreate_send(const struct lu_env *env, struct osp_device *d)
 	}
 
 	spin_lock(&d->opd_pre_lock);
-	if (d->opd_pre_grow_count > d->opd_pre_max_grow_count / 2)
-		d->opd_pre_grow_count = d->opd_pre_max_grow_count / 2;
-	grow = d->opd_pre_grow_count;
+	if (d->opd_pre_create_count > d->opd_pre_max_create_count / 2)
+		d->opd_pre_create_count = d->opd_pre_max_create_count / 2;
+	grow = d->opd_pre_create_count;
 	spin_unlock(&d->opd_pre_lock);
 
 	body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
@@ -585,15 +651,9 @@ static int osp_precreate_send(const struct lu_env *env, struct osp_device *d)
 
 	*fid = d->opd_pre_last_created_fid;
 	rc = osp_precreate_fids(env, d, fid, &grow);
-	if (rc == 1) {
+	if (rc == 1)
 		/* Current seq has been used up*/
-		if (!osp_is_fid_client(d)) {
-			osp_pre_update_status(d, -ENOSPC);
-			rc = -ENOSPC;
-		}
-		wake_up(&d->opd_pre_waitq);
-		GOTO(out_req, rc);
-	}
+		GOTO(out_req, rc = -ENOSPC);
 
 	if (!osp_is_fid_client(d)) {
 		/* Non-FID client will always send seq 0 because of
@@ -607,10 +667,16 @@ static int osp_precreate_send(const struct lu_env *env, struct osp_device *d)
 
 	ptlrpc_request_set_replen(req);
 
+	if (OBD_FAIL_CHECK(OBD_FAIL_OSP_FAKE_PRECREATE))
+		GOTO(ready, rc = 0);
+
 	rc = ptlrpc_queue_wait(req);
 	if (rc) {
 		CERROR("%s: can't precreate: rc = %d\n", d->opd_obd->obd_name,
 		       rc);
+		if (req->rq_net_err)
+			/* have osp_precreate_reserve() to wait for repeat */
+			rc = -ENOTCONN;
 		GOTO(out_req, rc);
 	}
 	LASSERT(req->rq_transno == 0);
@@ -620,8 +686,10 @@ static int osp_precreate_send(const struct lu_env *env, struct osp_device *d)
 		GOTO(out_req, rc = -EPROTO);
 
 	ostid_to_fid(fid, &body->oa.o_oi, d->opd_index);
+
+ready:
 	if (osp_fid_diff(fid, &d->opd_pre_used_fid) <= 0) {
-		CERROR("%s: precreate fid "DFID" < local used fid "DFID
+		CERROR("%s: precreate fid "DFID" <= local used fid "DFID
 		       ": rc = %d\n", d->opd_obd->obd_name,
 		       PFID(fid), PFID(&d->opd_pre_used_fid), -ESTALE);
 		GOTO(out_req, rc = -ESTALE);
@@ -633,13 +701,13 @@ static int osp_precreate_send(const struct lu_env *env, struct osp_device *d)
 	if (diff < grow) {
 		/* the OST has not managed to create all the
 		 * objects we asked for */
-		d->opd_pre_grow_count = max(diff, OST_MIN_PRECREATE);
-		d->opd_pre_grow_slow = 1;
+		d->opd_pre_create_count = max(diff, OST_MIN_PRECREATE);
+		d->opd_pre_create_slow = 1;
 	} else {
 		/* the OST is able to keep up with the work,
-		 * we could consider increasing grow_count
+		 * we could consider increasing create_count
 		 * next time if needed */
-		d->opd_pre_grow_slow = 0;
+		d->opd_pre_create_slow = 0;
 	}
 
 	body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
@@ -656,6 +724,9 @@ out_req:
 	osp_pre_update_status(d, rc);
 	wake_up(&d->opd_pre_user_waitq);
 
+	/* pause to let osp_precreate_reserve to go first */
+	CFS_FAIL_TIMEOUT(OBD_FAIL_OSP_PRECREATE_PAUSE, 2);
+
 	ptlrpc_req_finished(req);
 	RETURN(rc);
 }
@@ -770,7 +841,6 @@ static int osp_precreate_cleanup_orphans(struct lu_env *env,
 	struct ptlrpc_request	*req = NULL;
 	struct obd_import	*imp;
 	struct ost_body		*body;
-	struct l_wait_info	 lwi = { 0 };
 	int			 update_status = 0;
 	int			 rc;
 	int			 diff;
@@ -795,11 +865,10 @@ static int osp_precreate_cleanup_orphans(struct lu_env *env,
 	 * catch all osp_precreate_reserve() calls who find
 	 * "!opd_pre_recovering".
 	 */
-	l_wait_event(d->opd_pre_waitq,
-		     (!d->opd_pre_reserved && d->opd_recovery_completed) ||
-		     !osp_precreate_running(d) || d->opd_got_disconnected,
-		     &lwi);
-	if (!osp_precreate_running(d) || d->opd_got_disconnected)
+	wait_event_idle(d->opd_pre_waitq,
+			(!d->opd_pre_reserved && d->opd_recovery_completed) ||
+			!d->opd_pre_task || d->opd_got_disconnected);
+	if (!d->opd_pre_task || d->opd_got_disconnected)
 		GOTO(out, rc = -EAGAIN);
 
 	CDEBUG(D_HA, "%s: going to cleanup orphans since "DFID"\n",
@@ -861,10 +930,10 @@ static int osp_precreate_cleanup_orphans(struct lu_env *env,
 	spin_lock(&d->opd_pre_lock);
 	diff = osp_fid_diff(&d->opd_last_used_fid, last_fid);
 	if (diff > 0) {
-		d->opd_pre_grow_count = OST_MIN_PRECREATE + diff;
+		d->opd_pre_create_count = OST_MIN_PRECREATE + diff;
 		d->opd_pre_last_created_fid = d->opd_last_used_fid;
 	} else {
-		d->opd_pre_grow_count = OST_MIN_PRECREATE;
+		d->opd_pre_create_count = OST_MIN_PRECREATE;
 		d->opd_pre_last_created_fid = *last_fid;
 	}
 	/*
@@ -874,7 +943,7 @@ static int osp_precreate_cleanup_orphans(struct lu_env *env,
 	LASSERT(fid_oid(&d->opd_pre_last_created_fid) <=
 		LUSTRE_DATA_SEQ_MAX_WIDTH);
 	d->opd_pre_used_fid = d->opd_pre_last_created_fid;
-	d->opd_pre_grow_slow = 0;
+	d->opd_pre_create_slow = 0;
 	spin_unlock(&d->opd_pre_lock);
 
 	CDEBUG(D_HA, "%s: Got last_id "DFID" from OST, last_created "DFID
@@ -884,10 +953,6 @@ out:
 	if (req)
 		ptlrpc_req_finished(req);
 
-	spin_lock(&d->opd_pre_lock);
-	d->opd_pre_recovering = 0;
-	spin_unlock(&d->opd_pre_lock);
-
 	/*
 	 * If rc is zero, the pre-creation window should have been emptied.
 	 * Since waking up the herd would be useless without pre-created
@@ -906,6 +971,10 @@ out:
 		} else {
 			wake_up(&d->opd_pre_user_waitq);
 		}
+	} else {
+		spin_lock(&d->opd_pre_lock);
+		d->opd_pre_recovering = 0;
+		spin_unlock(&d->opd_pre_lock);
 	}
 
 	RETURN(rc);
@@ -919,71 +988,106 @@ out:
  * data is used to make this decision. If the latest result of statfs
  * request (rc argument) is not success, then just mark OSP unavailable
  * right away.
-
- * Add a bit of hysteresis so this flag isn't continually flapping,
- * and ensure that new files don't get extremely fragmented due to
- * only a small amount of available space in the filesystem.
- * We want to set the NOSPC flag when there is less than ~0.1% free
- * and clear it when there is at least ~0.2% free space, so:
- *                   avail < ~0.1% max          max = avail + used
- *            1025 * avail < avail + used       used = blocks - free
- *            1024 * avail < used
- *            1024 * avail < blocks - free
- *                   avail < ((blocks - free) >> 10)
- *
- * On very large disk, say 16TB 0.1% will be 16 GB. We don't want to
- * lose that amount of space so in those cases we report no space left
- * if their is less than 1 GB left.
- * the function updates current precreation status used: functional or not
  *
- * \param[in] d		OSP device
- * \param[in] rc	new precreate status for device \a d
+ * The new statfs data is passed in \a msfs and needs to be stored into
+ * opd_statfs, but only after the various flags in os_state are set, so
+ * that the new statfs data is not visible without appropriate flags set.
+ * As such, there is no need to clear the flags here, since this is called
+ * with new statfs data, and they should not be cleared if sent from OST.
  *
- * \retval 0		on success
- * \retval negative	negated errno on error
+ * Add a bit of hysteresis so this flag isn't continually flapping, and
+ * ensure that new files don't get extremely fragmented due to only a
+ * small amount of available space in the filesystem.  We want to set
+ * the ENOSPC/ENOINO flags unconditionally when there is less than the
+ * reserved size free, and still copy them from the old state when there
+ * is less than 2*reserved size free space or inodes.
+ *
+ * \param[in] d		OSP device
+ * \param[in] msfs	statfs data
  */
-void osp_pre_update_status(struct osp_device *d, int rc)
+static void osp_pre_update_msfs(struct osp_device *d, struct obd_statfs *msfs)
 {
-	struct obd_statfs	*msfs = &d->opd_statfs;
-	int			 old = d->opd_pre_status;
-	__u64			 used;
-
-	d->opd_pre_status = rc;
-	if (rc)
-		goto out;
-
-	if (likely(msfs->os_type)) {
-		used = min_t(__u64, (msfs->os_blocks - msfs->os_bfree) >> 10,
-				    1 << 30);
-		if ((msfs->os_ffree < 32) || (msfs->os_bavail < used)) {
-			d->opd_pre_status = -ENOSPC;
-			if (old != -ENOSPC)
-				CDEBUG(D_INFO, "%s: status: "LPU64" blocks, "
-				       LPU64" free, "LPU64" used, "LPU64" "
-				       "avail -> %d: rc = %d\n",
-				       d->opd_obd->obd_name, msfs->os_blocks,
-				       msfs->os_bfree, used, msfs->os_bavail,
-				       d->opd_pre_status, rc);
-			CDEBUG(D_INFO,
-			       "non-commited changes: %lu, in progress: %u\n",
-			       d->opd_syn_changes, d->opd_syn_rpc_in_progress);
-		} else if (old == -ENOSPC) {
-			d->opd_pre_status = 0;
-			spin_lock(&d->opd_pre_lock);
-			d->opd_pre_grow_slow = 0;
-			d->opd_pre_grow_count = OST_MIN_PRECREATE;
-			spin_unlock(&d->opd_pre_lock);
-			wake_up(&d->opd_pre_waitq);
-			CDEBUG(D_INFO, "%s: no space: "LPU64" blocks, "LPU64
-			       " free, "LPU64" used, "LPU64" avail -> %d: "
-			       "rc = %d\n", d->opd_obd->obd_name,
-			       msfs->os_blocks, msfs->os_bfree, used,
-			       msfs->os_bavail, d->opd_pre_status, rc);
+	u32 old_state = d->opd_statfs.os_state;
+	u32 reserved_ino_low = 32;	/* could be tunable in the future */
+	u32 reserved_ino_high = reserved_ino_low * 2;
+	u64 available_mb;
+
+	/* statfs structure not initialized yet */
+	if (unlikely(!msfs->os_type))
+		return;
+
+	/* if the low and high watermarks have not been initialized yet */
+	if (unlikely(d->opd_reserved_mb_high == 0 &&
+		     d->opd_reserved_mb_low == 0)) {
+		/* Use ~0.1% by default to disable object allocation,
+		 * and ~0.2% to enable, size in MB, set both watermark
+		 */
+		spin_lock(&d->opd_pre_lock);
+		if (d->opd_reserved_mb_high == 0 &&
+		    d->opd_reserved_mb_low == 0) {
+			d->opd_reserved_mb_low = ((msfs->os_bsize >> 10) *
+						  msfs->os_blocks) >> 20;
+			if (d->opd_reserved_mb_low == 0)
+				d->opd_reserved_mb_low = 1;
+			d->opd_reserved_mb_high =
+				(d->opd_reserved_mb_low << 1) + 1;
 		}
+		spin_unlock(&d->opd_pre_lock);
 	}
 
-out:
-	wake_up(&d->opd_pre_user_waitq);
+	available_mb = (msfs->os_bavail * (msfs->os_bsize >> 10)) >> 10;
+	if (msfs->os_ffree < reserved_ino_low)
+		msfs->os_state |= OS_STATFS_ENOINO;
+	else if (msfs->os_ffree <= reserved_ino_high)
+		msfs->os_state |= old_state & OS_STATFS_ENOINO;
+	/* else don't clear flags in new msfs->os_state sent from OST */
+
+	CDEBUG(D_INFO,
+	       "%s: blocks=%llu free=%llu avail=%llu avail_mb=%llu hwm_mb=%u files=%llu ffree=%llu state=%x: rc = %d\n",
+	       d->opd_obd->obd_name, msfs->os_blocks, msfs->os_bfree,
+	       msfs->os_bavail, available_mb, d->opd_reserved_mb_high,
+	       msfs->os_files, msfs->os_ffree, msfs->os_state,
+	       d->opd_pre_status);
+	if (available_mb < d->opd_reserved_mb_low)
+		msfs->os_state |= OS_STATFS_ENOSPC;
+	else if (available_mb <= d->opd_reserved_mb_high)
+		msfs->os_state |= old_state & OS_STATFS_ENOSPC;
+	/* else don't clear flags in new msfs->os_state sent from OST */
+
+	if (msfs->os_state & (OS_STATFS_ENOINO | OS_STATFS_ENOSPC)) {
+		d->opd_pre_status = -ENOSPC;
+		if (!(old_state & (OS_STATFS_ENOINO | OS_STATFS_ENOSPC)))
+			CDEBUG(D_INFO, "%s: full: state=%x: rc = %x\n",
+			       d->opd_obd->obd_name, msfs->os_state,
+			       d->opd_pre_status);
+		CDEBUG(D_INFO, "uncommitted changes=%u in_progress=%u\n",
+		       atomic_read(&d->opd_sync_changes),
+		       atomic_read(&d->opd_sync_rpcs_in_progress));
+	} else if (old_state & (OS_STATFS_ENOINO | OS_STATFS_ENOSPC)) {
+		d->opd_pre_status = 0;
+		spin_lock(&d->opd_pre_lock);
+		d->opd_pre_create_slow = 0;
+		d->opd_pre_create_count = OST_MIN_PRECREATE;
+		spin_unlock(&d->opd_pre_lock);
+		wake_up(&d->opd_pre_waitq);
+
+		CDEBUG(D_INFO,
+		       "%s: available: state=%x: rc = %d\n",
+		       d->opd_obd->obd_name, msfs->os_state,
+		       d->opd_pre_status);
+	} else {
+		/* we only get here if rc == 0 in the caller */
+		d->opd_pre_status = 0;
+	}
+
+	/* Object precreation skipped on OST if manually disabled */
+	if (d->opd_pre_max_create_count == 0)
+		msfs->os_state |= OS_STATFS_NOPRECREATE;
+	/* else don't clear flags in new msfs->os_state sent from OST */
+
+	/* copy only new statfs state to make it visible to MDS threads */
+	if (&d->opd_statfs != msfs)
+		d->opd_statfs = *msfs;
 }
 
 /**
@@ -1013,9 +1117,27 @@ int osp_init_pre_fid(struct osp_device *osp)
 
 	LASSERT(osp->opd_pre != NULL);
 
-	/* Return if last_used fid has been initialized */
+	/* Let's check if the current last_seq/fid is valid,
+	 * otherwise request new sequence from the controller */
+	if (osp_is_fid_client(osp) && osp->opd_group != 0) {
+		/* Non-MDT0 can only use normal sequence for
+		 * OST objects */
+		if (fid_is_norm(&osp->opd_last_used_fid))
+			RETURN(0);
+	} else {
+		/* Initially MDT0 will start with IDIF, after
+		 * that it will request new sequence from the
+		 * controller */
+		if (fid_is_idif(&osp->opd_last_used_fid) ||
+		    fid_is_norm(&osp->opd_last_used_fid))
+			RETURN(0);
+	}
+
 	if (!fid_is_zero(&osp->opd_last_used_fid))
-		RETURN(0);
+		CWARN("%s: invalid last used fid "DFID
+		      ", try to get new sequence.\n",
+		      osp->opd_obd->obd_name,
+		      PFID(&osp->opd_last_used_fid));
 
 	rc = lu_env_init(&env, osp->opd_dt_dev.dd_lu_dev.ld_type->ldt_ctx_tags);
 	if (rc) {
@@ -1058,6 +1180,11 @@ out:
 	RETURN(rc);
 }
 
+struct opt_args {
+	struct osp_device	*opta_dev;
+	struct lu_env		opta_env;
+	struct completion	*opta_started;
+};
 /**
  * The core of precreate functionality
  *
@@ -1076,83 +1203,91 @@ out:
  * \retval 0		on success
  * \retval negative	negated errno on error
  */
-static int osp_precreate_thread(void *_arg)
+static int osp_precreate_thread(void *_args)
 {
-	struct osp_device	*d = _arg;
-	struct ptlrpc_thread	*thread = &d->opd_pre_thread;
-	struct l_wait_info	 lwi = { 0 };
-	struct lu_env		 env;
+	struct opt_args		*args = _args;
+	struct osp_device	*d = args->opta_dev;
+	struct lu_env		*env = &args->opta_env;
 	int			 rc;
 
 	ENTRY;
 
-	rc = lu_env_init(&env, d->opd_dt_dev.dd_lu_dev.ld_type->ldt_ctx_tags);
-	if (rc) {
-		CERROR("%s: init env error: rc = %d\n", d->opd_obd->obd_name,
-		       rc);
-		RETURN(rc);
-	}
-
-	spin_lock(&d->opd_pre_lock);
-	thread->t_flags = SVC_RUNNING;
-	spin_unlock(&d->opd_pre_lock);
-	wake_up(&thread->t_ctl_waitq);
-
-	while (osp_precreate_running(d)) {
+	complete(args->opta_started);
+	while (!kthread_should_stop()) {
 		/*
 		 * need to be connected to OST
 		 */
-		while (osp_precreate_running(d)) {
-			l_wait_event(d->opd_pre_waitq,
-				     !osp_precreate_running(d) ||
-				     d->opd_new_connection,
-				     &lwi);
+		while (!kthread_should_stop()) {
+			if ((d->opd_pre == NULL || d->opd_pre_recovering) &&
+			    d->opd_imp_connected &&
+			    !d->opd_got_disconnected)
+				break;
+			wait_event_idle(d->opd_pre_waitq,
+					kthread_should_stop() ||
+					d->opd_new_connection);
 
 			if (!d->opd_new_connection)
 				continue;
 
+			OBD_FAIL_TIMEOUT(OBD_FAIL_OSP_CON_EVENT_DELAY,
+					 cfs_fail_val);
 			d->opd_new_connection = 0;
 			d->opd_got_disconnected = 0;
 			break;
 		}
 
-		if (!osp_precreate_running(d))
+		if (kthread_should_stop())
 			break;
 
-		LASSERT(d->opd_obd->u.cli.cl_seq != NULL);
-		/* Sigh, fid client is not ready yet */
-		if (d->opd_obd->u.cli.cl_seq->lcs_exp == NULL)
-			continue;
+		if (d->opd_pre) {
+			LASSERT(d->opd_obd->u.cli.cl_seq != NULL);
+			/* Sigh, fid client is not ready yet */
+			if (d->opd_obd->u.cli.cl_seq->lcs_exp == NULL)
+				continue;
 
-		/* Init fid for osp_precreate if necessary */
-		rc = osp_init_pre_fid(d);
-		if (rc != 0) {
-			class_export_put(d->opd_exp);
-			d->opd_obd->u.cli.cl_seq->lcs_exp = NULL;
-			CERROR("%s: init pre fid error: rc = %d\n",
-			       d->opd_obd->obd_name, rc);
+			/* Init fid for osp_precreate if necessary */
+			rc = osp_init_pre_fid(d);
+			if (rc != 0) {
+				class_export_put(d->opd_exp);
+				d->opd_obd->u.cli.cl_seq->lcs_exp = NULL;
+				CERROR("%s: init pre fid error: rc = %d\n",
+						d->opd_obd->obd_name, rc);
+				continue;
+			}
+		}
+
+		if (osp_statfs_update(env, d)) {
+			if (wait_event_idle_timeout(d->opd_pre_waitq,
+						    kthread_should_stop(),
+						    cfs_time_seconds(5)) == 0)
+				l_wait_event_abortable(
+					d->opd_pre_waitq,
+					kthread_should_stop());
 			continue;
 		}
 
-		osp_statfs_update(d);
+		if (d->opd_pre) {
+			/*
+			 * Clean up orphans or recreate missing objects.
+			 */
+			rc = osp_precreate_cleanup_orphans(env, d);
+			if (rc != 0) {
+				schedule_timeout_interruptible(cfs_time_seconds(1));
+				continue;
+			}
+		}
 
 		/*
-		 * Clean up orphans or recreate missing objects.
-		 */
-		rc = osp_precreate_cleanup_orphans(&env, d);
-		if (rc != 0)
-			continue;
-		/*
 		 * connected, can handle precreates now
 		 */
-		while (osp_precreate_running(d)) {
-			l_wait_event(d->opd_pre_waitq,
-				     !osp_precreate_running(d) ||
-				     osp_precreate_near_empty(&env, d) ||
-				     osp_statfs_need_update(d) ||
-				     d->opd_got_disconnected, &lwi);
-
-			if (!osp_precreate_running(d))
+		while (!kthread_should_stop()) {
+			wait_event_idle(d->opd_pre_waitq,
+					kthread_should_stop() ||
+					osp_precreate_near_empty(env, d) ||
+					osp_statfs_need_update(d) ||
+					d->opd_got_disconnected);
+
+			if (kthread_should_stop())
 				break;
 
 			/* something happened to the connection
@@ -1161,28 +1296,32 @@ static int osp_precreate_thread(void *_arg)
 				break;
 
 			if (osp_statfs_need_update(d))
-				osp_statfs_update(d);
+				if (osp_statfs_update(env, d))
+					break;
+
+			if (d->opd_pre == NULL)
+				continue;
 
 			/* To avoid handling different seq in precreate/orphan
 			 * cleanup, it will hold precreate until current seq is
 			 * used up. */
-			if (unlikely(osp_precreate_end_seq(&env, d) &&
-			    !osp_create_end_seq(&env, d)))
+			if (unlikely(osp_precreate_end_seq(env, d) &&
+			    !osp_create_end_seq(env, d)))
 				continue;
 
-			if (unlikely(osp_precreate_end_seq(&env, d) &&
-				     osp_create_end_seq(&env, d))) {
-				LCONSOLE_INFO("%s:"LPX64" is used up."
+			if (unlikely(osp_precreate_end_seq(env, d) &&
+				     osp_create_end_seq(env, d))) {
+				LCONSOLE_INFO("%s:%#llx is used up."
 					      " Update to new seq\n",
 					      d->opd_obd->obd_name,
 					 fid_seq(&d->opd_pre_last_created_fid));
-				rc = osp_precreate_rollover_new_seq(&env, d);
+				rc = osp_precreate_rollover_new_seq(env, d);
 				if (rc)
 					continue;
 			}
 
-			if (osp_precreate_near_empty(&env, d)) {
-				rc = osp_precreate_send(&env, d);
+			if (osp_precreate_near_empty(env, d)) {
+				rc = osp_precreate_send(env, d);
 				/* osp_precreate_send() sets opd_pre_status
 				 * in case of error, that prevent the using of
 				 * failed device. */
@@ -1195,9 +1334,8 @@ static int osp_precreate_thread(void *_arg)
 		}
 	}
 
-	thread->t_flags = SVC_STOPPED;
-	lu_env_fini(&env);
-	wake_up(&thread->t_ctl_waitq);
+	lu_env_fini(env);
+	OBD_FREE_PTR(args);
 
 	RETURN(0);
 }
@@ -1228,7 +1366,8 @@ static int osp_precreate_ready_condition(const struct lu_env *env,
 		return 1;
 
 	/* ready if OST reported no space and no destroys in progress */
-	if (d->opd_syn_changes + d->opd_syn_rpc_in_progress == 0 &&
+	if (atomic_read(&d->opd_sync_changes) +
+	    atomic_read(&d->opd_sync_rpcs_in_progress) == 0 &&
 	    d->opd_pre_status == -ENOSPC)
 		return 1;
 
@@ -1236,6 +1375,7 @@ static int osp_precreate_ready_condition(const struct lu_env *env,
 	if (d->opd_pre_status != 0 &&
 	    d->opd_pre_status != -EAGAIN &&
 	    d->opd_pre_status != -ENODEV &&
+	    d->opd_pre_status != -ENOTCONN &&
 	    d->opd_pre_status != -ENOSPC) {
 		/* DEBUG LU-3230 */
 		if (d->opd_pre_status != -EIO)
@@ -1247,21 +1387,6 @@ static int osp_precreate_ready_condition(const struct lu_env *env,
 	return 0;
 }
 
-static int osp_precreate_timeout_condition(void *data)
-{
-	struct osp_device *d = data;
-
-	CDEBUG(D_HA, "%s: slow creates, last="DFID", next="DFID", "
-	      "reserved="LPU64", syn_changes=%lu, "
-	      "syn_rpc_in_progress=%d, status=%d\n",
-	      d->opd_obd->obd_name, PFID(&d->opd_pre_last_created_fid),
-	      PFID(&d->opd_pre_used_fid), d->opd_pre_reserved,
-	      d->opd_syn_changes, d->opd_syn_rpc_in_progress,
-	      d->opd_pre_status);
-
-	return 1;
-}
-
 /**
  * Reserve object in precreate pool
  *
@@ -1286,11 +1411,11 @@ static int osp_precreate_timeout_condition(void *data)
  * \retval		-EAGAIN try later, slow precreation in progress
  * \retval		-EIO when no access to OST
  */
-int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
+int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d,
+			  bool can_block)
 {
-	struct l_wait_info	 lwi;
-	cfs_time_t		 expire = cfs_time_shift(obd_timeout);
-	int			 precreated, rc;
+	time64_t expire = ktime_get_seconds() + obd_timeout;
+	int precreated, rc, synced = 0;
 
 	ENTRY;
 
@@ -1298,6 +1423,10 @@ int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
 		 "Next FID "DFID"\n", PFID(&d->opd_pre_last_created_fid),
 		 PFID(&d->opd_pre_used_fid));
 
+	/* opd_pre_max_create_count 0 to not use specified OST. */
+	if (d->opd_pre_max_create_count == 0)
+		RETURN(-ENOBUFS);
+
 	/*
 	 * wait till:
 	 *  - preallocation is done
@@ -1312,12 +1441,12 @@ int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
 		 * increase number of precreations
 		 */
 		precreated = osp_objs_precreated(env, d);
-		if (d->opd_pre_grow_count < d->opd_pre_max_grow_count &&
-		    d->opd_pre_grow_slow == 0 &&
-		    precreated <= (d->opd_pre_grow_count / 4 + 1)) {
+		if (d->opd_pre_create_count < d->opd_pre_max_create_count &&
+		    d->opd_pre_create_slow == 0 &&
+		    precreated <= (d->opd_pre_create_count / 4 + 1)) {
 			spin_lock(&d->opd_pre_lock);
-			d->opd_pre_grow_slow = 1;
-			d->opd_pre_grow_count *= 2;
+			d->opd_pre_create_slow = 1;
+			d->opd_pre_create_count *= 2;
 			spin_unlock(&d->opd_pre_lock);
 		}
 
@@ -1345,16 +1474,19 @@ int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
 		 * wait till that is done - some space might be released
 		 */
 		if (unlikely(rc == -ENOSPC)) {
-			if (d->opd_syn_changes) {
+			if (atomic_read(&d->opd_sync_changes) && synced == 0) {
 				/* force local commit to release space */
 				dt_commit_async(env, d->opd_storage);
+				osp_sync_check_for_work(d);
+				synced = 1;
 			}
-			if (d->opd_syn_rpc_in_progress) {
-				/* just wait till destroys are done */
-				/* see l_wait_even() few lines below */
+			if (atomic_read(&d->opd_sync_rpcs_in_progress)) {
+				/* just wait till destroys are done
+				 * see wait_event_idle_timeout() below
+				 */
 			}
-			if (d->opd_syn_changes +
-			    d->opd_syn_rpc_in_progress == 0) {
+			if (atomic_read(&d->opd_sync_changes) +
+			    atomic_read(&d->opd_sync_rpcs_in_progress) == 0) {
 				/* no hope for free space */
 				break;
 			}
@@ -1363,15 +1495,32 @@ int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
 		/* XXX: don't wake up if precreation is in progress */
 		wake_up(&d->opd_pre_waitq);
 
-		lwi = LWI_TIMEOUT(expire - cfs_time_current(),
-				osp_precreate_timeout_condition, d);
-		if (cfs_time_aftereq(cfs_time_current(), expire)) {
+		if (ktime_get_seconds() >= expire) {
 			rc = -ETIMEDOUT;
 			break;
 		}
 
-		l_wait_event(d->opd_pre_user_waitq,
-			     osp_precreate_ready_condition(env, d), &lwi);
+		if (!can_block) {
+			LASSERT(d->opd_pre);
+			rc = -ENOBUFS;
+			break;
+		}
+
+		if (wait_event_idle_timeout(
+			    d->opd_pre_user_waitq,
+			    osp_precreate_ready_condition(env, d),
+			    cfs_time_seconds(obd_timeout)) == 0) {
+			CDEBUG(D_HA,
+			       "%s: slow creates, last="DFID", next="DFID", "
+			       "reserved=%llu, sync_changes=%u, "
+			       "sync_rpcs_in_progress=%d, status=%d\n",
+			       d->opd_obd->obd_name,
+			       PFID(&d->opd_pre_last_created_fid),
+			       PFID(&d->opd_pre_used_fid), d->opd_pre_reserved,
+			       atomic_read(&d->opd_sync_changes),
+			       atomic_read(&d->opd_sync_rpcs_in_progress),
+			       d->opd_pre_status);
+		}
 	}
 
 	RETURN(rc);
@@ -1402,6 +1551,7 @@ int osp_precreate_reserve(const struct lu_env *env, struct osp_device *d)
 int osp_precreate_get_fid(const struct lu_env *env, struct osp_device *d,
 			  struct lu_fid *fid)
 {
+	struct lu_fid *pre_used_fid = &d->opd_pre_used_fid;
 	/* grab next id from the pool */
 	spin_lock(&d->opd_pre_lock);
 
@@ -1411,6 +1561,20 @@ int osp_precreate_get_fid(const struct lu_env *env, struct osp_device *d,
 		 PFID(&d->opd_pre_used_fid),
 		 PFID(&d->opd_pre_last_created_fid));
 
+	/*
+	 * When sequence is used up, new one should be allocated in
+	 * osp_precreate_rollover_new_seq. So ASSERT here to avoid
+	 * objid overflow.
+	 */
+	LASSERTF(osp_fid_end_seq(env, pre_used_fid) == 0,
+		 "next fid "DFID" last created fid "DFID"\n",
+		 PFID(&d->opd_pre_used_fid),
+		 PFID(&d->opd_pre_last_created_fid));
+	/* Non IDIF fids shoulnd't get here with oid == 0xFFFFFFFF. */
+	if (fid_is_idif(pre_used_fid) &&
+	    unlikely(fid_oid(pre_used_fid) == LUSTRE_DATA_SEQ_MAX_WIDTH))
+		pre_used_fid->f_seq++;
+
 	d->opd_pre_used_fid.f_oid++;
 	memcpy(fid, &d->opd_pre_used_fid, sizeof(*fid));
 	d->opd_pre_reserved--;
@@ -1426,7 +1590,8 @@ int osp_precreate_get_fid(const struct lu_env *env, struct osp_device *d,
 	 * all reservations are released, see comment in
 	 * osp_precreate_thread() just before orphan cleanup
 	 */
-	if (unlikely(d->opd_pre_reserved == 0 && d->opd_pre_status))
+	if (unlikely(d->opd_pre_reserved == 0 &&
+		     (d->opd_pre_recovering || d->opd_pre_status)))
 		wake_up(&d->opd_pre_waitq);
 
 	return 0;
@@ -1467,8 +1632,6 @@ int osp_object_truncate(const struct lu_env *env, struct dt_object *dt,
 	if (req == NULL)
 		RETURN(-ENOMEM);
 
-	/* XXX: capa support? */
-	/* osc_set_capa_size(req, &RMF_CAPA1, capa); */
 	rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_PUNCH);
 	if (rc) {
 		ptlrpc_request_free(req);
@@ -1479,6 +1642,13 @@ int osp_object_truncate(const struct lu_env *env, struct dt_object *dt,
 	 * XXX: decide how do we do here with resend
 	 * if we don't resend, then client may see wrong file size
 	 * if we do resend, then MDS thread can get stuck for quite long
+	 * and if we don't resend, then client will also get -EAGAIN !!
+	 * (see LU-7975 and sanity/test_27F use cases)
+	 * but let's decide not to resend/delay this truncate request to OST
+	 * and allow Client to decide to resend, in a less agressive way from
+	 * after_reply(), by returning -EINPROGRESS instead of
+	 * -EAGAIN/-EAGAIN upon return from ptlrpc_queue_wait() at the
+	 * end of this routine
 	 */
 	req->rq_no_resend = req->rq_no_delay = 1;
 
@@ -1506,8 +1676,23 @@ int osp_object_truncate(const struct lu_env *env, struct dt_object *dt,
 	ptlrpc_request_set_replen(req);
 
 	rc = ptlrpc_queue_wait(req);
-	if (rc)
-		CERROR("can't punch object: %d\n", rc);
+	if (rc) {
+		/* -EAGAIN/-EWOULDBLOCK means OST is unreachable at the moment
+		 * since we have decided not to resend/delay, but this could
+		 * lead to wrong size to be seen at Client side and even process
+		 * trying to open to exit/fail if not itself handling -EAGAIN.
+		 * So it should be better to return -EINPROGRESS instead and
+		 * leave the decision to resend at Client side in after_reply()
+		 */
+		if (rc == -EAGAIN) {
+			rc = -EINPROGRESS;
+			CDEBUG(D_HA, "returning -EINPROGRESS instead of "
+			       "-EWOULDBLOCK/-EAGAIN to allow Client to "
+			       "resend\n");
+		} else {
+			CERROR("can't punch object: %d\n", rc);
+		}
+	}
 out:
 	ptlrpc_req_finished(req);
 	if (oa)
@@ -1527,9 +1712,6 @@ out:
  */
 int osp_init_precreate(struct osp_device *d)
 {
-	struct l_wait_info	 lwi = { 0 };
-	struct task_struct		*task;
-
 	ENTRY;
 
 	OBD_ALLOC_PTR(d->opd_pre);
@@ -1537,46 +1719,21 @@ int osp_init_precreate(struct osp_device *d)
 		RETURN(-ENOMEM);
 
 	/* initially precreation isn't ready */
+	init_waitqueue_head(&d->opd_pre_user_waitq);
 	d->opd_pre_status = -EAGAIN;
 	fid_zero(&d->opd_pre_used_fid);
 	d->opd_pre_used_fid.f_oid = 1;
 	fid_zero(&d->opd_pre_last_created_fid);
 	d->opd_pre_last_created_fid.f_oid = 1;
+	d->opd_last_id = 0;
 	d->opd_pre_reserved = 0;
 	d->opd_got_disconnected = 1;
-	d->opd_pre_grow_slow = 0;
-	d->opd_pre_grow_count = OST_MIN_PRECREATE;
-	d->opd_pre_min_grow_count = OST_MIN_PRECREATE;
-	d->opd_pre_max_grow_count = OST_MAX_PRECREATE;
-
-	spin_lock_init(&d->opd_pre_lock);
-	init_waitqueue_head(&d->opd_pre_waitq);
-	init_waitqueue_head(&d->opd_pre_user_waitq);
-	init_waitqueue_head(&d->opd_pre_thread.t_ctl_waitq);
-
-	/*
-	 * Initialize statfs-related things
-	 */
-	d->opd_statfs_maxage = 5; /* default update interval */
-	d->opd_statfs_fresh_till = cfs_time_shift(-1000);
-	CDEBUG(D_OTHER, "current %llu, fresh till %llu\n",
-	       (unsigned long long)cfs_time_current(),
-	       (unsigned long long)d->opd_statfs_fresh_till);
-	cfs_timer_init(&d->opd_statfs_timer, osp_statfs_timer_cb, d);
-
-	/*
-	 * start thread handling precreation and statfs updates
-	 */
-	task = kthread_run(osp_precreate_thread, d,
-			   "osp-pre-%u-%u", d->opd_index, d->opd_group);
-	if (IS_ERR(task)) {
-		CERROR("can't start precreate thread %ld\n", PTR_ERR(task));
-		RETURN(PTR_ERR(task));
-	}
-
-	l_wait_event(d->opd_pre_thread.t_ctl_waitq,
-		     osp_precreate_running(d) || osp_precreate_stopped(d),
-		     &lwi);
+	d->opd_pre_create_slow = 0;
+	d->opd_pre_create_count = OST_MIN_PRECREATE;
+	d->opd_pre_min_create_count = OST_MIN_PRECREATE;
+	d->opd_pre_max_create_count = OST_MAX_PRECREATE;
+	d->opd_reserved_mb_high = 0;
+	d->opd_reserved_mb_low = 0;
 
 	RETURN(0);
 }
@@ -1592,25 +1749,86 @@ int osp_init_precreate(struct osp_device *d)
  */
 void osp_precreate_fini(struct osp_device *d)
 {
-	struct ptlrpc_thread *thread;
-
 	ENTRY;
 
-	cfs_timer_disarm(&d->opd_statfs_timer);
-
 	if (d->opd_pre == NULL)
 		RETURN_EXIT;
 
-	thread = &d->opd_pre_thread;
-
-	thread->t_flags = SVC_STOPPING;
-	wake_up(&d->opd_pre_waitq);
-
-	wait_event(thread->t_ctl_waitq, thread->t_flags & SVC_STOPPED);
-
 	OBD_FREE_PTR(d->opd_pre);
 	d->opd_pre = NULL;
 
 	EXIT;
 }
 
+int osp_init_statfs(struct osp_device *d)
+{
+	struct task_struct	*task;
+	struct opt_args		*args;
+	DECLARE_COMPLETION_ONSTACK(started);
+	int			rc;
+
+	ENTRY;
+
+	spin_lock_init(&d->opd_pre_lock);
+	init_waitqueue_head(&d->opd_pre_waitq);
+
+	/*
+	 * Initialize statfs-related things
+	 */
+	d->opd_statfs_maxage = 5; /* defaultupdate interval */
+	d->opd_statfs_fresh_till = ktime_sub_ns(ktime_get(),
+						1000 * NSEC_PER_SEC);
+	CDEBUG(D_OTHER, "current %lldns, fresh till %lldns\n",
+	       ktime_get_ns(),
+	       ktime_to_ns(d->opd_statfs_fresh_till));
+	cfs_timer_setup(&d->opd_statfs_timer, osp_statfs_timer_cb,
+			(unsigned long)d, 0);
+
+	if (d->opd_storage->dd_rdonly)
+		RETURN(0);
+
+	OBD_ALLOC_PTR(args);
+	if (!args)
+		RETURN(0);
+	args->opta_dev = d;
+	args->opta_started = &started;
+	rc = lu_env_init(&args->opta_env,
+			 d->opd_dt_dev.dd_lu_dev.ld_type->ldt_ctx_tags);
+	if (rc) {
+		CERROR("%s: init env error: rc = %d\n", d->opd_obd->obd_name,
+		       rc);
+		OBD_FREE_PTR(args);
+		RETURN(0);
+	}
+
+	/*
+	 * start thread handling precreation and statfs updates
+	 */
+	task = kthread_create(osp_precreate_thread, args,
+			      "osp-pre-%u-%u", d->opd_index, d->opd_group);
+	if (IS_ERR(task)) {
+		CERROR("can't start precreate thread %ld\n", PTR_ERR(task));
+		lu_env_fini(&args->opta_env);
+		OBD_FREE_PTR(args);
+		RETURN(PTR_ERR(task));
+	}
+	d->opd_pre_task = task;
+	wake_up_process(task);
+	wait_for_completion(&started);
+
+	RETURN(0);
+}
+
+void osp_statfs_fini(struct osp_device *d)
+{
+	struct task_struct *task = d->opd_pre_task;
+	ENTRY;
+
+	del_timer(&d->opd_statfs_timer);
+
+	d->opd_pre_task = NULL;
+	if (task)
+		kthread_stop(task);
+
+	EXIT;
+}