1 files changed, 27 insertions, 9 deletions

diff --git a/sys/fs/nfsclient/nfs_clvfsops.c b/sys/fs/nfsclient/nfs_clvfsops.c
index 49047f69a612..5e89f0c18f75 100644
--- a/sys/fs/nfsclient/nfs_clvfsops.c
+++ b/sys/fs/nfsclient/nfs_clvfsops.c
@@ -552,7 +552,7 @@ static void
 nfs_decode_args(struct mount *mp, struct nfsmount *nmp, struct nfs_args *argp,
     const char *hostname, struct ucred *cred, struct thread *td)
 {
-	int s;
+	int i, s;
 	int adjsock;
 	char *p;
 
@@ -621,18 +621,36 @@ nfs_decode_args(struct mount *mp, struct nfsmount *nmp, struct nfs_args *argp,
 
 	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
 		nmp->nm_wsize = argp->wsize;
-		/* Round down to multiple of blocksize */
-		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
-		if (nmp->nm_wsize <= 0)
-			nmp->nm_wsize = NFS_FABLKSIZE;
+		/*
+		 * Clip at the power of 2 below the size. There is an
+		 * issue (not isolated) that causes intermittent page
+		 * faults if this is not done.
+		 */
+		i = NFS_FABLKSIZE;
+		for (;;) {
+			if (i * 2 > nmp->nm_wsize) {
+				nmp->nm_wsize = i;
+				break;
+			}
+			i *= 2;
+		}
 	}
 
 	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
 		nmp->nm_rsize = argp->rsize;
-		/* Round down to multiple of blocksize */
-		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
-		if (nmp->nm_rsize <= 0)
-			nmp->nm_rsize = NFS_FABLKSIZE;
+		/*
+		 * Clip at the power of 2 below the size. There is an
+		 * issue (not isolated) that causes intermittent page
+		 * faults if this is not done.
+		 */
+		i = NFS_FABLKSIZE;
+		for (;;) {
+			if (i * 2 > nmp->nm_rsize) {
+				nmp->nm_rsize = i;
+				break;
+			}
+			i *= 2;
+		}
 	}
 
 	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {