pNFS: If we have to delay the layout callback, mark the layout for return

If the client needs to delay the layout callback, then speed up the recall
process by marking the remaining layout segments to be actively returned
by the client.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/callback_proc.c

@@ -181,9 +181,19 @@ static u32 initiate_file_draining(struct nfs_client *clp,
 	pnfs_layoutcommit_inode(ino, false);
 
 	spin_lock(&ino->i_lock);
-	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
-	    pnfs_mark_matching_lsegs_invalid(lo, &free_me_list,
+	/*
+	 * Enforce RFC5661 Section 12.5.5.2.1.5 (Bulk Recall and Return)
+	 */
+	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		rv = NFS4ERR_DELAY;
+		goto unlock;
+	}
+
+	if (pnfs_mark_matching_lsegs_invalid(lo, &free_me_list,
 					&args->cbl_range)) {
+		pnfs_mark_matching_lsegs_return(lo,
+				&free_me_list,
+				&args->cbl_range);
 		rv = NFS4ERR_DELAY;
 		goto unlock;
 	}

fs/nfs/pnfs.c

@@ -1756,7 +1756,7 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 	goto out;
 }
 
-static void
+void
 pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
 				struct list_head *tmp_list,
 				struct pnfs_layout_range *return_range)
@@ -1768,6 +1768,8 @@ pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
 	if (list_empty(&lo->plh_segs))
 		return;
 
+	assert_spin_locked(&lo->plh_inode->i_lock);
+
 	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 		if (should_free_lseg(&lseg->pls_range, return_range)) {
 			dprintk("%s: marking lseg %p iomode %d "

fs/nfs/pnfs.h

@@ -266,6 +266,9 @@ int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 				struct list_head *tmp_list,
 				struct pnfs_layout_range *recall_range);
+void pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
+				struct list_head *tmp_list,
+				struct pnfs_layout_range *recall_range);
 bool pnfs_roc(struct inode *ino);
 void pnfs_roc_release(struct inode *ino);
 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);