[PATCH v3 5/5] Documentation: update nfs option in filesystem/vfat.txt

[Namjae Jeon <linkinjeon@gmail.com>]

From: Namjae Jeon <namjae.jeon@samsung.com>

update nfs option in filesystem/vfat.txt

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
---
 Documentation/filesystems/vfat.txt |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index de1e6c4..3371b8e 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -141,13 +141,22 @@ discard       -- If set, issues discard/TRIM commands to the block
 		 device when blocks are freed. This is useful for SSD devices
 		 and sparse/thinly-provisoned LUNs.
 
-nfs           -- This option maintains an index (cache) of directory
-		 inodes by i_logstart which is used by the nfs-related code to
-		 improve look-ups.
-
-		 Enable this only if you want to export the FAT filesystem
+nfs=full_unstable|limited_stable
+	      -- Enable this only if you want to export the FAT filesystem
 		 over NFS
 
+		 full_unstable:This option maintains an index (cache) of
+		 directory inodes by i_logstart which is used by
+		 the nfs-related code to improve look-ups.Full file operations
+		 (read/write) over NFS is supported but with cache eviction
+		 at NFS server, this could result in ESTALE issues.
+
+		 limited_stable:This options makes NFS support for FAT as
+		 read-only and provides stable inode based on the on-disk
+		 location of the MS-DOS directory entry.This helps in
+		 reconstruction of the inodes in case of lookup failure,
+		 making FAT behaviour stable with respect to ESTALE issues.
+
 <bool>: 0,1,yes,no,true,false
 
 TODO
-- 
1.7.9.5