2 files changed, 21 insertions, 9 deletions

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index e9cc3f0d58e2..a7b1d86b37c7 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -23,6 +23,9 @@
 #define FAT_ERRORS_PANIC        2      /* panic on error */
 #define FAT_ERRORS_RO           3      /* remount r/o on error */
 
+#define FAT_NFS_STALE_RW        1      /* NFS RW support, can cause ESTALE */
+#define FAT_NFS_NOSTALE_RO      2      /* NFS RO support, no ESTALE issue */
+
 struct fat_mount_options {
         kuid_t fs_uid;
         kgid_t fs_gid;
@@ -34,6 +37,7 @@ struct fat_mount_options {
         unsigned short shortname;  /* flags for shortname display/create rule */
         unsigned char name_check;  /* r = relaxed, n = normal, s = strict */
         unsigned char errors;      /* On error: continue, panic, remount-ro */
+        unsigned char nfs;        /* NFS support: nostale_ro, stale_rw */
         unsigned short allow_utime;/* permission for setting the [am]time */
         unsigned quiet:1,          /* set = fake successful chmods and chowns */
                  showexec:1,       /* set = only set x bit for com/exe/bat */
@@ -48,8 +52,7 @@ struct fat_mount_options {
                  usefree:1,        /* Use free_clusters for FAT32 */
                  tz_set:1,         /* Filesystem timestamps' offset set */
                  rodir:1,          /* allow ATTR_RO for directory */
-                 discard:1,        /* Issue discard requests on deletions */
-                 nfs:1;            /* Do extra work needed for NFS export */
+                 discard:1;        /* Issue discard requests on deletions */
 };
 
 #define FAT_HASH_BITS   8
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index acf6e479b443..93fbc8a7f098 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -814,8 +814,6 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
                 seq_puts(m, ",usefree");
         if (opts->quiet)
                 seq_puts(m, ",quiet");
-        if (opts->nfs)
-                seq_puts(m, ",nfs");
         if (opts->showexec)
                 seq_puts(m, ",showexec");
         if (opts->sys_immutable)
@@ -849,6 +847,10 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
                 seq_puts(m, ",errors=panic");
         else
                 seq_puts(m, ",errors=remount-ro");
+        if (opts->nfs == FAT_NFS_NOSTALE_RO)
+                seq_puts(m, ",nfs=nostale_ro");
+        else if (opts->nfs)
+                seq_puts(m, ",nfs=stale_rw");
         if (opts->discard)
                 seq_puts(m, ",discard");
 
@@ -865,7 +867,7 @@ enum {
         Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
         Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
         Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
-        Opt_err,
+        Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err,
 };
 
 static const match_table_t fat_tokens = {
@@ -895,7 +897,9 @@ static const match_table_t fat_tokens = {
         {Opt_err_panic, "errors=panic"},
         {Opt_err_ro, "errors=remount-ro"},
         {Opt_discard, "discard"},
-        {Opt_nfs, "nfs"},
+        {Opt_nfs_stale_rw, "nfs"},
+        {Opt_nfs_stale_rw, "nfs=stale_rw"},
+        {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
         {Opt_obsolete, "conv=binary"},
         {Opt_obsolete, "conv=text"},
         {Opt_obsolete, "conv=auto"},
@@ -1092,6 +1096,12 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
                 case Opt_err_ro:
                         opts->errors = FAT_ERRORS_RO;
                         break;
+                case Opt_nfs_stale_rw:
+                        opts->nfs = FAT_NFS_STALE_RW;
+                        break;
+                case Opt_nfs_nostale_ro:
+                        opts->nfs = FAT_NFS_NOSTALE_RO;
+                        break;
 
                 /* msdos specific */
                 case Opt_dots:
@@ -1150,9 +1160,6 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
                 case Opt_discard:
                         opts->discard = 1;
                         break;
-                case Opt_nfs:
-                        opts->nfs = 1;
-                        break;
 
                 /* obsolete mount options */
                 case Opt_obsolete:
@@ -1183,6 +1190,8 @@ out:
                 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
         if (opts->unicode_xlate)
                 opts->utf8 = 0;
+        if (opts->nfs == FAT_NFS_NOSTALE_RO)
+                sb->s_flags |= MS_RDONLY;
 
         return 0;
 }