Merge branch 'layoutfixes'

* layoutfixes:
  NFSv4.1/pnfs: Remove redundant wakeup in pnfs_send_layoutreturn()
  NFSv4.1/pnfs: Remove redundant check in pnfs_layoutgets_blocked()
  NFSv4.1/pnfs: Remove redundant lo->plh_block_lgets in layoutreturn
  NFSv4.1/pnfs: Don't prevent layoutgets when doing return-on-close
  NFSv4.1/pnfs: Fix serialisation of layout return and layoutget
  NFSv4.1/pnfs: Remove redundant checks in pnfs_layoutgets_blocked()
  pNFS: Tighten up locking around DS commit buckets

fs/nfs/pnfs.c

@@ -368,7 +368,6 @@ pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo)
 	if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 		return false;
 	lo->plh_return_iomode = 0;
-	lo->plh_block_lgets++;
 	pnfs_get_layout_hdr(lo);
 	clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &lo->plh_flags);
 	return true;
@@ -817,25 +816,12 @@ pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 	return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 }
 
-static bool
-pnfs_layout_returning(const struct pnfs_layout_hdr *lo,
-		      struct pnfs_layout_range *range)
-{
-	return test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
-		(lo->plh_return_iomode == IOMODE_ANY ||
-		 lo->plh_return_iomode == range->iomode);
-}
-
 /* lget is set to 1 if called from inside send_layoutget call chain */
 static bool
-pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo,
-			struct pnfs_layout_range *range, int lget)
+pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 {
 	return lo->plh_block_lgets ||
-		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
-		(list_empty(&lo->plh_segs) &&
-		 (atomic_read(&lo->plh_outstanding) > lget)) ||
-		pnfs_layout_returning(lo, range);
+		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 }
 
 int
@@ -847,7 +833,7 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
 
 	dprintk("--> %s\n", __func__);
 	spin_lock(&lo->plh_inode->i_lock);
-	if (pnfs_layoutgets_blocked(lo, range, 1)) {
+	if (pnfs_layoutgets_blocked(lo)) {
 		status = -EAGAIN;
 	} else if (!nfs4_valid_open_stateid(open_state)) {
 		status = -EBADF;
@@ -956,9 +942,7 @@ pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, nfs4_stateid stateid,
 	if (unlikely(lrp == NULL)) {
 		status = -ENOMEM;
 		spin_lock(&ino->i_lock);
-		lo->plh_block_lgets--;
 		pnfs_clear_layoutreturn_waitbit(lo);
-		rpc_wake_up(&NFS_SERVER(ino)->roc_rpcwaitq);
 		spin_unlock(&ino->i_lock);
 		pnfs_put_layout_hdr(lo);
 		goto out;
@@ -1107,7 +1091,9 @@ bool pnfs_roc(struct inode *ino)
 		}
 	if (!found)
 		goto out_noroc;
-	lo->plh_block_lgets++;
+	if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
+		goto out_noroc;
+	lo->plh_return_iomode = IOMODE_ANY;
 	pnfs_get_layout_hdr(lo); /* matched in pnfs_roc_release */
 	spin_unlock(&ino->i_lock);
 	pnfs_free_lseg_list(&tmp_list);
@@ -1135,7 +1121,7 @@ void pnfs_roc_release(struct inode *ino)
 
 	spin_lock(&ino->i_lock);
 	lo = NFS_I(ino)->layout;
-	lo->plh_block_lgets--;
+	pnfs_clear_layoutreturn_waitbit(lo);
 	if (atomic_dec_and_test(&lo->plh_refcount)) {
 		pnfs_detach_layout_hdr(lo);
 		spin_unlock(&ino->i_lock);
@@ -1438,6 +1424,8 @@ static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key)
 
 static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
 {
+	if (!pnfs_should_retry_layoutget(lo))
+		return false;
 	/*
 	 * send layoutcommit as it can hold up layoutreturn due to lseg
 	 * reference
@@ -1533,8 +1521,7 @@ lookup_again:
 	 * Because we free lsegs before sending LAYOUTRETURN, we need to wait
 	 * for LAYOUTRETURN even if first is true.
 	 */
-	if (!lseg && pnfs_should_retry_layoutget(lo) &&
-	    test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 		spin_unlock(&ino->i_lock);
 		dprintk("%s wait for layoutreturn\n", __func__);
 		if (pnfs_prepare_to_retry_layoutget(lo)) {
@@ -1547,7 +1534,7 @@ lookup_again:
 		goto out_put_layout_hdr;
 	}
 
-	if (pnfs_layoutgets_blocked(lo, &arg, 0))
+	if (pnfs_layoutgets_blocked(lo))
 		goto out_unlock;
 	atomic_inc(&lo->plh_outstanding);
 	spin_unlock(&ino->i_lock);
@@ -1619,12 +1606,7 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 	lseg->pls_range = res->range;
 
 	spin_lock(&ino->i_lock);
-	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
-		dprintk("%s forget reply due to recall\n", __func__);
-		goto out_forget_reply;
-	}
-
-	if (pnfs_layoutgets_blocked(lo, &lgp->args.range, 1)) {
+	if (pnfs_layoutgets_blocked(lo)) {
 		dprintk("%s forget reply due to state\n", __func__);
 		goto out_forget_reply;
 	}

fs/nfs/pnfs_nfs.c

@@ -124,11 +124,12 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 	if (ret) {
 		cinfo->ds->nwritten -= ret;
 		cinfo->ds->ncommitting += ret;
-		bucket->clseg = bucket->wlseg;
-		if (list_empty(src))
+		if (bucket->clseg == NULL)
+			bucket->clseg = pnfs_get_lseg(bucket->wlseg);
+		if (list_empty(src)) {
+			pnfs_put_lseg_locked(bucket->wlseg);
 			bucket->wlseg = NULL;
-		else
-			pnfs_get_lseg(bucket->clseg);
+		}
 	}
 	return ret;
 }
@@ -182,19 +183,23 @@ static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 	struct pnfs_commit_bucket *bucket;
 	struct pnfs_layout_segment *freeme;
+	LIST_HEAD(pages);
 	int i;
 
+	spin_lock(cinfo->lock);
 	for (i = idx; i < fl_cinfo->nbuckets; i++) {
 		bucket = &fl_cinfo->buckets[i];
 		if (list_empty(&bucket->committing))
 			continue;
-		nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo, i);
-		spin_lock(cinfo->lock);
 		freeme = bucket->clseg;
 		bucket->clseg = NULL;
+		list_splice_init(&bucket->committing, &pages);
 		spin_unlock(cinfo->lock);
+		nfs_retry_commit(&pages, freeme, cinfo, i);
 		pnfs_put_lseg(freeme);
+		spin_lock(cinfo->lock);
 	}
+	spin_unlock(cinfo->lock);
 }
 
 static unsigned int
@@ -216,10 +221,6 @@ pnfs_generic_alloc_ds_commits(struct nfs_commit_info *cinfo,
 		if (!data)
 			break;
 		data->ds_commit_index = i;
-		spin_lock(cinfo->lock);
-		data->lseg = bucket->clseg;
-		bucket->clseg = NULL;
-		spin_unlock(cinfo->lock);
 		list_add(&data->pages, list);
 		nreq++;
 	}
@@ -229,6 +230,22 @@ pnfs_generic_alloc_ds_commits(struct nfs_commit_info *cinfo,
 	return nreq;
 }
 
+static inline
+void pnfs_fetch_commit_bucket_list(struct list_head *pages,
+		struct nfs_commit_data *data,
+		struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_bucket *bucket;
+
+	bucket = &cinfo->ds->buckets[data->ds_commit_index];
+	spin_lock(cinfo->lock);
+	list_splice_init(pages, &bucket->committing);
+	data->lseg = bucket->clseg;
+	bucket->clseg = NULL;
+	spin_unlock(cinfo->lock);
+
+}
+
 /* This follows nfs_commit_list pretty closely */
 int
 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
@@ -243,7 +260,7 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 	if (!list_empty(mds_pages)) {
 		data = nfs_commitdata_alloc();
 		if (data != NULL) {
-			data->lseg = NULL;
+			data->ds_commit_index = -1;
 			list_add(&data->pages, &list);
 			nreq++;
 		} else {
@@ -265,19 +282,16 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 
 	list_for_each_entry_safe(data, tmp, &list, pages) {
 		list_del_init(&data->pages);
-		if (!data->lseg) {
+		if (data->ds_commit_index < 0) {
 			nfs_init_commit(data, mds_pages, NULL, cinfo);
 			nfs_initiate_commit(NFS_CLIENT(inode), data,
 					    NFS_PROTO(data->inode),
 					    data->mds_ops, how, 0);
 		} else {
-			struct pnfs_commit_bucket *buckets;
+			LIST_HEAD(pages);
 
-			buckets = cinfo->ds->buckets;
-			nfs_init_commit(data,
-					&buckets[data->ds_commit_index].committing,
-					data->lseg,
-					cinfo);
+			pnfs_fetch_commit_bucket_list(&pages, data, cinfo);
+			nfs_init_commit(data, &pages, data->lseg, cinfo);
 			initiate_commit(data, how);
 		}
 	}