fat (exportfs): fix dentry reconnection

Maintain an index of directory inodes by starting cluster, so that
fat_get_parent() can return the proper cached inode rather than inventing
one that cannot be traced back to the filesystem root.

Add a new msdos/vfat binary mount option "nfs" so that FAT filesystems
that are _not_ exported via NFS are not saddled with maintenance of an
index they will never use.

Finally, simplify NFS file handle generation and lookups.  An
ext2-congruent implementation is adequate for FAT needs.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index b0e12bf9f4a1..c27c63020292 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -440,7 +440,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
         struct inode *old_inode, *new_inode;
         struct fat_slot_info old_sinfo, sinfo;
         struct timespec ts;
-        loff_t dotdot_i_pos, new_i_pos;
+        loff_t new_i_pos;
         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 
         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
@@ -456,8 +456,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
         is_dir = S_ISDIR(old_inode->i_mode);
         update_dotdot = (is_dir && old_dir != new_dir);
         if (update_dotdot) {
-                if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
-                                         &dotdot_i_pos) < 0) {
+                if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
                         err = -EIO;
                         goto out;
                 }