[PATCH 3/3] NFS: Add mount options supporting eager writes

[trondmy@xxxxxxxxxx]

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
 fs/nfs/fs_context.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 06894bcdea2d..b6be02aa79f0 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -82,6 +82,7 @@ enum nfs_param {
 	Opt_v,
 	Opt_vers,
 	Opt_wsize,
+	Opt_write,
 };
 
 enum {
@@ -113,6 +114,19 @@ static const struct constant_table nfs_param_enums_lookupcache[] = {
 	{}
 };
 
+enum {
+	Opt_write_lazy,
+	Opt_write_eager,
+	Opt_write_wait,
+};
+
+static const struct constant_table nfs_param_enums_write[] = {
+	{ "lazy",		Opt_write_lazy },
+	{ "eager",		Opt_write_eager },
+	{ "wait",		Opt_write_wait },
+	{}
+};
+
 static const struct fs_parameter_spec nfs_fs_parameters[] = {
 	fsparam_flag_no("ac",		Opt_ac),
 	fsparam_u32   ("acdirmax",	Opt_acdirmax),
@@ -171,6 +185,7 @@ static const struct fs_parameter_spec nfs_fs_parameters[] = {
 	fsparam_flag  ("v4.1",		Opt_v),
 	fsparam_flag  ("v4.2",		Opt_v),
 	fsparam_string("vers",		Opt_vers),
+	fsparam_enum  ("write",		Opt_write, nfs_param_enums_write),
 	fsparam_u32   ("wsize",		Opt_wsize),
 	{}
 };
@@ -770,6 +785,24 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
 			goto out_invalid_value;
 		}
 		break;
+	case Opt_write:
+		switch (result.uint_32) {
+		case Opt_write_lazy:
+			ctx->flags &=
+				~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
+			break;
+		case Opt_write_eager:
+			ctx->flags |= NFS_MOUNT_WRITE_EAGER;
+			ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
+			break;
+		case Opt_write_wait:
+			ctx->flags |=
+				NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
+			break;
+		default:
+			goto out_invalid_value;
+		}
+		break;
 
 		/*
 		 * Special options
-- 
2.29.2