NFSv4.1: Add helpers for setting/reading the I/O fail bit

...and make them local to the pnfs.c file.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index df45aca..f46f9bc 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -238,6 +238,27 @@
 	}
 }
 
+static int
+pnfs_iomode_to_fail_bit(u32 iomode)
+{
+	return iomode == IOMODE_RW ?
+		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
+}
+
+static void
+pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
+{
+	set_bit(pnfs_iomode_to_fail_bit(iomode), &lo->plh_flags);
+	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
+			iomode == IOMODE_RW ?  "RW" : "READ");
+}
+
+static bool
+pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
+{
+	return test_bit(pnfs_iomode_to_fail_bit(iomode), &lo->plh_flags) != 0;
+}
+
 static void
 init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
 {
@@ -612,7 +633,7 @@
 			break;
 		default:
 			/* remember that LAYOUTGET failed and suspend trying */
-			set_bit(lo_fail_bit(range->iomode), &lo->plh_flags);
+			pnfs_layout_io_set_failed(lo, range->iomode);
 		}
 		return NULL;
 	}
@@ -669,8 +690,8 @@
 	lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
 	if (unlikely(lrp == NULL)) {
 		status = -ENOMEM;
-		set_bit(NFS_LAYOUT_RW_FAILED, &lo->plh_flags);
-		set_bit(NFS_LAYOUT_RO_FAILED, &lo->plh_flags);
+		pnfs_layout_io_set_failed(lo, IOMODE_RW);
+		pnfs_layout_io_set_failed(lo, IOMODE_READ);
 		pnfs_clear_layout_returned(lo);
 		pnfs_put_layout_hdr(lo);
 		goto out;
@@ -1019,7 +1040,6 @@
 		.length = count,
 	};
 	unsigned pg_offset;
-	struct nfs_inode *nfsi = NFS_I(ino);
 	struct nfs_server *server = NFS_SERVER(ino);
 	struct nfs_client *clp = server->nfs_client;
 	struct pnfs_layout_hdr *lo;
@@ -1044,7 +1064,7 @@
 	}
 
 	/* if LAYOUTGET already failed once we don't try again */
-	if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
+	if (pnfs_layout_io_test_failed(lo, iomode))
 		goto out_unlock;
 
 	/* Check to see if the layout for the given range already exists */
@@ -1585,13 +1605,7 @@
 
 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
 {
-	if (lseg->pls_range.iomode == IOMODE_RW) {
-		dprintk("%s Setting layout IOMODE_RW fail bit\n", __func__);
-		set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
-	} else {
-		dprintk("%s Setting layout IOMODE_READ fail bit\n", __func__);
-		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
-	}
+	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
 }
 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
 
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 0495879..e3eb7d1 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -274,12 +274,6 @@
 	return test_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
 }
 
-static inline int lo_fail_bit(u32 iomode)
-{
-	return iomode == IOMODE_RW ?
-			 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
-}
-
 static inline struct pnfs_layout_segment *
 pnfs_get_lseg(struct pnfs_layout_segment *lseg)
 {