1 files changed, 376 insertions, 139 deletions

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 8b37e7f8e789..e7ddbce48321 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -59,6 +59,17 @@ void pnfs_generic_commit_release(void *calldata)
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
 
+static struct pnfs_layout_segment *
+pnfs_free_bucket_lseg(struct pnfs_commit_bucket *bucket)
+{
+	if (list_empty(&bucket->committing) && list_empty(&bucket->written)) {
+		struct pnfs_layout_segment *freeme = bucket->lseg;
+		bucket->lseg = NULL;
+		return freeme;
+	}
+	return NULL;
+}
+
 /* The generic layer is about to remove the req from the commit list.
  * If this will make the bucket empty, it will need to put the lseg reference.
  * Note this must be called holding nfsi->commit_mutex
@@ -78,8 +89,7 @@ pnfs_generic_clear_request_commit(struct nfs_page *req,
 		bucket = list_first_entry(&req->wb_list,
 					  struct pnfs_commit_bucket,
 					  written);
-		freeme = bucket->wlseg;
-		bucket->wlseg = NULL;
+		freeme = pnfs_free_bucket_lseg(bucket);
 	}
 out:
 	nfs_request_remove_commit_list(req, cinfo);
@@ -87,10 +97,154 @@ out:
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
 
+struct pnfs_commit_array *
+pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
+{
+	struct pnfs_commit_array *p;
+	struct pnfs_commit_bucket *b;
+
+	p = kmalloc(struct_size(p, buckets, n), gfp_flags);
+	if (!p)
+		return NULL;
+	p->nbuckets = n;
+	INIT_LIST_HEAD(&p->cinfo_list);
+	INIT_LIST_HEAD(&p->lseg_list);
+	p->lseg = NULL;
+	for (b = &p->buckets[0]; n != 0; b++, n--) {
+		INIT_LIST_HEAD(&b->written);
+		INIT_LIST_HEAD(&b->committing);
+		b->lseg = NULL;
+		b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
+	}
+	return p;
+}
+EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);
+
+void
+pnfs_free_commit_array(struct pnfs_commit_array *p)
+{
+	kfree_rcu(p, rcu);
+}
+EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
+
+static struct pnfs_commit_array *
+pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (array->lseg == lseg)
+			return array;
+	}
+	return NULL;
+}
+
+struct pnfs_commit_array *
+pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_commit_array *new,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	if (array)
+		return array;
+	new->lseg = lseg;
+	refcount_set(&new->refcount, 1);
+	list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
+	list_add(&new->lseg_list, &lseg->pls_commits);
+	return new;
+}
+EXPORT_SYMBOL_GPL(pnfs_add_commit_array);
+
+static struct pnfs_commit_array *
+pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	rcu_read_lock();
+	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	if (!array) {
+		rcu_read_unlock();
+		fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
+		rcu_read_lock();
+		array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	}
+	rcu_read_unlock();
+	return array;
+}
+
+static void
+pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
+{
+	list_del_rcu(&array->cinfo_list);
+	list_del(&array->lseg_list);
+	pnfs_free_commit_array(array);
+}
+
+static void
+pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
+{
+	if (refcount_dec_and_test(&array->refcount))
+		pnfs_release_commit_array_locked(array);
+}
+
+static void
+pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
+{
+	if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
+		pnfs_release_commit_array_locked(array);
+		spin_unlock(&inode->i_lock);
+	}
+}
+
+static struct pnfs_commit_array *
+pnfs_get_commit_array(struct pnfs_commit_array *array)
+{
+	if (refcount_inc_not_zero(&array->refcount))
+		return array;
+	return NULL;
+}
+
+static void
+pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
+{
+	array->lseg = NULL;
+	list_del_init(&array->lseg_list);
+	pnfs_put_commit_array_locked(array);
+}
+
+void
+pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array, *tmp;
+
+	list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
+		pnfs_remove_and_free_commit_array(array);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);
+
+void
+pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
+{
+	struct pnfs_commit_array *array, *tmp;
+
+	list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
+		pnfs_remove_and_free_commit_array(array);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);
+
+/*
+ * Locks the nfs_page requests for commit and moves them to
+ * @bucket->committing.
+ */
 static int
-pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
-				 struct nfs_commit_info *cinfo,
-				 int max)
+pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
+				struct nfs_commit_info *cinfo,
+				int max)
 {
 	struct list_head *src = &bucket->written;
 	struct list_head *dst = &bucket->committing;
@@ -101,158 +255,254 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 	if (ret) {
 		cinfo->ds->nwritten -= ret;
 		cinfo->ds->ncommitting += ret;
-		if (bucket->clseg == NULL)
-			bucket->clseg = pnfs_get_lseg(bucket->wlseg);
-		if (list_empty(src)) {
-			pnfs_put_lseg(bucket->wlseg);
-			bucket->wlseg = NULL;
-		}
 	}
 	return ret;
 }
 
+static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
+				  struct pnfs_commit_bucket *buckets,
+				  unsigned int nbuckets,
+				  int max)
+{
+	unsigned int i;
+	int rv = 0, cnt;
+
+	for (i = 0; i < nbuckets && max != 0; i++) {
+		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
+		rv += cnt;
+		max -= cnt;
+	}
+	return rv;
+}
+
 /* Move reqs from written to committing lists, returning count
  * of number moved.
  */
-int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
-				   int max)
+int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
 {
-	int i, rv = 0, cnt;
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	int rv = 0, cnt;
 
-	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
-	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
-		cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
-						       cinfo, max);
-		max -= cnt;
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
+				array->nbuckets, max);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
 		rv += cnt;
+		max -= cnt;
+		if (!max)
+			break;
 	}
+	rcu_read_unlock();
 	return rv;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
 
-/* Pull everything off the committing lists and dump into @dst.  */
-void pnfs_generic_recover_commit_reqs(struct list_head *dst,
-				      struct nfs_commit_info *cinfo)
+static unsigned int
+pnfs_bucket_recover_commit_reqs(struct list_head *dst,
+			        struct pnfs_commit_bucket *buckets,
+				unsigned int nbuckets,
+				struct nfs_commit_info *cinfo)
 {
 	struct pnfs_commit_bucket *b;
 	struct pnfs_layout_segment *freeme;
-	int nwritten;
-	int i;
+	unsigned int nwritten, ret = 0;
+	unsigned int i;
 
-	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
 restart:
-	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
 		nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
 		if (!nwritten)
 			continue;
-		cinfo->ds->nwritten -= nwritten;
-		if (list_empty(&b->written)) {
-			freeme = b->wlseg;
-			b->wlseg = NULL;
+		ret += nwritten;
+		freeme = pnfs_free_bucket_lseg(b);
+		if (freeme) {
 			pnfs_put_lseg(freeme);
 			goto restart;
 		}
 	}
+	return ret;
+}
+
+/* Pull everything off the committing lists and dump into @dst.  */
+void pnfs_generic_recover_commit_reqs(struct list_head *dst,
+				      struct nfs_commit_info *cinfo)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	unsigned int nwritten;
+
+	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		nwritten = pnfs_bucket_recover_commit_reqs(dst,
+							   array->buckets,
+							   array->nbuckets,
+							   cinfo);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
+		fl_cinfo->nwritten -= nwritten;
+	}
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
 
-static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
+static struct nfs_page *
+pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
+		unsigned int nbuckets, struct page *page)
+{
+	struct nfs_page *req;
+	struct pnfs_commit_bucket *b;
+	unsigned int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
+		list_for_each_entry(req, &b->written, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+		list_for_each_entry(req, &b->committing, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+	}
+	return NULL;
+}
+
+/* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+struct nfs_page *
+pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	struct nfs_page *req;
+
+	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
+		req = pnfs_bucket_search_commit_reqs(array->buckets,
+				array->nbuckets, page);
+		if (req)
+			return req;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
+
+static struct pnfs_layout_segment *
+pnfs_bucket_get_committing(struct list_head *head,
+			   struct pnfs_commit_bucket *bucket,
+			   struct nfs_commit_info *cinfo)
+{
+	struct list_head *pos;
+
+	list_for_each(pos, &bucket->committing)
+		cinfo->ds->ncommitting--;
+	list_splice_init(&bucket->committing, head);
+	return pnfs_free_bucket_lseg(bucket);
+}
+
+static struct nfs_commit_data *
+pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
+			     struct nfs_commit_info *cinfo)
+{
+	struct nfs_commit_data *data = nfs_commitdata_alloc(false);
+
+	if (!data)
+		return NULL;
+	data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
+	if (!data->lseg)
+		data->lseg = pnfs_get_lseg(bucket->lseg);
+	return data;
+}
+
+static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
+				      unsigned int nbuckets,
+				      struct nfs_commit_info *cinfo,
+				      unsigned int idx)
+{
 	struct pnfs_commit_bucket *bucket;
 	struct pnfs_layout_segment *freeme;
-	struct list_head *pos;
 	LIST_HEAD(pages);
-	int i;
 
-	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
-	for (i = idx; i < fl_cinfo->nbuckets; i++) {
-		bucket = &fl_cinfo->buckets[i];
+	for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
 		if (list_empty(&bucket->committing))
 			continue;
-		freeme = bucket->clseg;
-		bucket->clseg = NULL;
-		list_for_each(pos, &bucket->committing)
-			cinfo->ds->ncommitting--;
-		list_splice_init(&bucket->committing, &pages);
+		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+		freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
 		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
-		nfs_retry_commit(&pages, freeme, cinfo, i);
+		nfs_retry_commit(&pages, freeme, cinfo, idx);
 		pnfs_put_lseg(freeme);
-		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
 	}
-	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 }
 
 static unsigned int
-pnfs_generic_alloc_ds_commits(struct nfs_commit_info *cinfo,
-			      struct list_head *list)
+pnfs_bucket_alloc_ds_commits(struct list_head *list,
+			     struct pnfs_commit_bucket *buckets,
+			     unsigned int nbuckets,
+			     struct nfs_commit_info *cinfo)
 {
-	struct pnfs_ds_commit_info *fl_cinfo;
 	struct pnfs_commit_bucket *bucket;
 	struct nfs_commit_data *data;
-	int i;
+	unsigned int i;
 	unsigned int nreq = 0;
 
-	fl_cinfo = cinfo->ds;
-	bucket = fl_cinfo->buckets;
-	for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
+	for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
 		if (list_empty(&bucket->committing))
 			continue;
-		data = nfs_commitdata_alloc(false);
-		if (!data)
-			break;
-		data->ds_commit_index = i;
-		list_add(&data->pages, list);
-		nreq++;
+		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+		if (!list_empty(&bucket->committing)) {
+			data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
+			if (!data)
+				goto out_error;
+			data->ds_commit_index = i;
+			list_add_tail(&data->list, list);
+			atomic_inc(&cinfo->mds->rpcs_out);
+			nreq++;
+		}
+		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 	}
-
+	return nreq;
+out_error:
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 	/* Clean up on error */
-	pnfs_generic_retry_commit(cinfo, i);
+	pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
 	return nreq;
 }
 
-static inline
-void pnfs_fetch_commit_bucket_list(struct list_head *pages,
-		struct nfs_commit_data *data,
-		struct nfs_commit_info *cinfo)
+static unsigned int
+pnfs_alloc_ds_commits_list(struct list_head *list,
+			   struct pnfs_ds_commit_info *fl_cinfo,
+			   struct nfs_commit_info *cinfo)
 {
-	struct pnfs_commit_bucket *bucket;
-	struct list_head *pos;
-
-	bucket = &cinfo->ds->buckets[data->ds_commit_index];
-	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
-	list_for_each(pos, &bucket->committing)
-		cinfo->ds->ncommitting--;
-	list_splice_init(&bucket->committing, pages);
-	data->lseg = bucket->clseg;
-	bucket->clseg = NULL;
-	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
-
-}
+	struct pnfs_commit_array *array;
+	unsigned int ret = 0;
 
-/* Helper function for pnfs_generic_commit_pagelist to catch an empty
- * page list. This can happen when two commits race.
- *
- * This must be called instead of nfs_init_commit - call one or the other, but
- * not both!
- */
-static bool
-pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages,
-					  struct nfs_commit_data *data,
-					  struct nfs_commit_info *cinfo)
-{
-	if (list_empty(pages)) {
-		if (atomic_dec_and_test(&cinfo->mds->rpcs_out))
-			wake_up_var(&cinfo->mds->rpcs_out);
-		/* don't call nfs_commitdata_release - it tries to put
-		 * the open_context which is not acquired until nfs_init_commit
-		 * which has not been called on @data */
-		WARN_ON_ONCE(data->context);
-		nfs_commit_free(data);
-		return true;
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
+				array->nbuckets, cinfo);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
 	}
-
-	return false;
+	rcu_read_unlock();
+	return ret;
 }
 
 /* This follows nfs_commit_list pretty closely */
@@ -262,6 +512,7 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 			     int (*initiate_commit)(struct nfs_commit_data *data,
 						    int how))
 {
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 	struct nfs_commit_data *data, *tmp;
 	LIST_HEAD(list);
 	unsigned int nreq = 0;
@@ -269,40 +520,25 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 	if (!list_empty(mds_pages)) {
 		data = nfs_commitdata_alloc(true);
 		data->ds_commit_index = -1;
-		list_add(&data->pages, &list);
+		list_splice_init(mds_pages, &data->pages);
+		list_add_tail(&data->list, &list);
+		atomic_inc(&cinfo->mds->rpcs_out);
 		nreq++;
 	}
 
-	nreq += pnfs_generic_alloc_ds_commits(cinfo, &list);
-
+	nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
 	if (nreq == 0)
 		goto out;
 
-	atomic_add(nreq, &cinfo->mds->rpcs_out);
-
-	list_for_each_entry_safe(data, tmp, &list, pages) {
-		list_del_init(&data->pages);
+	list_for_each_entry_safe(data, tmp, &list, list) {
+		list_del(&data->list);
 		if (data->ds_commit_index < 0) {
-			/* another commit raced with us */
-			if (pnfs_generic_commit_cancel_empty_pagelist(mds_pages,
-				data, cinfo))
-				continue;
-
-			nfs_init_commit(data, mds_pages, NULL, cinfo);
+			nfs_init_commit(data, NULL, NULL, cinfo);
 			nfs_initiate_commit(NFS_CLIENT(inode), data,
 					    NFS_PROTO(data->inode),
 					    data->mds_ops, how, 0);
 		} else {
-			LIST_HEAD(pages);
-
-			pnfs_fetch_commit_bucket_list(&pages, data, cinfo);
-
-			/* another commit raced with us */
-			if (pnfs_generic_commit_cancel_empty_pagelist(&pages,
-				data, cinfo))
-				continue;
-
-			nfs_init_commit(data, &pages, data->lseg, cinfo);
+			nfs_init_commit(data, NULL, data->lseg, cinfo);
 			initiate_commit(data, how);
 		}
 	}
@@ -930,32 +1166,33 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
 				u32 ds_commit_idx)
 {
 	struct list_head *list;
-	struct pnfs_commit_bucket *buckets;
+	struct pnfs_commit_array *array;
+	struct pnfs_commit_bucket *bucket;
 
 	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
-	buckets = cinfo->ds->buckets;
-	list = &buckets[ds_commit_idx].written;
-	if (list_empty(list)) {
-		if (!pnfs_is_valid_lseg(lseg)) {
-			mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
-			cinfo->completion_ops->resched_write(cinfo, req);
-			return;
-		}
-		/* Non-empty buckets hold a reference on the lseg.  That ref
-		 * is normally transferred to the COMMIT call and released
-		 * there.  It could also be released if the last req is pulled
-		 * off due to a rewrite, in which case it will be done in
-		 * pnfs_common_clear_request_commit
-		 */
-		WARN_ON_ONCE(buckets[ds_commit_idx].wlseg != NULL);
-		buckets[ds_commit_idx].wlseg = pnfs_get_lseg(lseg);
-	}
+	array = pnfs_lookup_commit_array(cinfo->ds, lseg);
+	if (!array || !pnfs_is_valid_lseg(lseg))
+		goto out_resched;
+	bucket = &array->buckets[ds_commit_idx];
+	list = &bucket->written;
+	/* Non-empty buckets hold a reference on the lseg.  That ref
+	 * is normally transferred to the COMMIT call and released
+	 * there.  It could also be released if the last req is pulled
+	 * off due to a rewrite, in which case it will be done in
+	 * pnfs_common_clear_request_commit
+	 */
+	if (!bucket->lseg)
+		bucket->lseg = pnfs_get_lseg(lseg);
 	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
 	cinfo->ds->nwritten++;
 
 	nfs_request_add_commit_list_locked(req, list, cinfo);
 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 	nfs_mark_page_unstable(req->wb_page, cinfo);
+	return;
+out_resched:
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	cinfo->completion_ops->resched_write(cinfo, req);
 }
 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);