NFS: Added support to turn off the NFSv3 READDIRPLUS RPC.

READDIRPLUS can be a performance hindrance when the client is working with
large directories. In addition, some servers still have bugs in their
implementations (e.g. Tru64 returns wrong values for the fsid).

Add a mount flag to enable users to turn it off at mount time following the
implementation in Apple's NFS client.

Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 2190e6c..5bd03b9 100644 (file)
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -618,7 +618,8 @@ static int nfs_init_server(struct nfs_server *server, const struct nfs_mount_dat
        if (clp->cl_nfsversion == 3) {
                if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
                        server->namelen = NFS3_MAXNAMLEN;
-               server->caps |= NFS_CAP_READDIRPLUS;
+               if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
+                       server->caps |= NFS_CAP_READDIRPLUS;
        } else {
                if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
                        server->namelen = NFS2_MAXNAMLEN;

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 719464a..ca20d3c 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -290,6 +290,7 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
                { NFS_MOUNT_NOAC, ",noac", "" },
                { NFS_MOUNT_NONLM, ",nolock", "" },
                { NFS_MOUNT_NOACL, ",noacl", "" },
+               { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
                { 0, NULL, NULL }
        };
        const struct proc_nfs_info *nfs_infop;

diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h
index 659c754..cc8b9c5 100644 (file)
--- a/include/linux/nfs_mount.h
+++ b/include/linux/nfs_mount.h
@@ -61,6 +61,7 @@ struct nfs_mount_data {
 #define NFS_MOUNT_NOACL                0x0800  /* 4 */
 #define NFS_MOUNT_STRICTLOCK   0x1000  /* reserved for NFSv4 */
 #define NFS_MOUNT_SECFLAVOUR   0x2000  /* 5 */
+#define NFS_MOUNT_NORDIRPLUS   0x4000  /* 5 */
 #define NFS_MOUNT_FLAGMASK     0xFFFF
 
 #endif