pNFS: Add a helper to allocate the array of buckets

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/pnfs.h

@@ -366,6 +366,9 @@ bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
 
 /* pnfs_nfs.c */
+struct pnfs_commit_array *pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags);
+void pnfs_free_commit_array(struct pnfs_commit_array *p);
+
 void pnfs_generic_clear_request_commit(struct nfs_page *req,
 				       struct nfs_commit_info *cinfo);
 void pnfs_generic_commit_release(void *calldata);

fs/nfs/pnfs_nfs.c

@@ -87,6 +87,37 @@ pnfs_generic_clear_request_commit(struct nfs_page *req,
 }
 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->wlseg = NULL;
+		b->clseg = 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 int
 pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 				 struct nfs_commit_info *cinfo,

include/linux/nfs_xdr.h

@@ -1270,10 +1270,19 @@ struct pnfs_commit_bucket {
 	struct nfs_writeverf direct_verf;
 };
 
+struct pnfs_commit_array {
+	struct list_head cinfo_list;
+	struct list_head lseg_list;
+	struct pnfs_layout_segment *lseg;
+	struct rcu_head rcu;
+	unsigned int nbuckets;
+	struct pnfs_commit_bucket buckets[];
+};
+
 struct pnfs_ds_commit_info {
-	int nwritten;
-	int ncommitting;
-	int nbuckets;
+	unsigned int nwritten;
+	unsigned int ncommitting;
+	unsigned int nbuckets;
 	struct pnfs_commit_bucket *buckets;
 };