knfsd: exportfs: add procedural interface for NFSD

Currently NFSD calls directly into filesystems through the export_operations
structure.  I plan to change this interface in various ways in later patches,
and want to avoid the export of the default operations to NFSD, so this patch
adds two simple exportfs_encode_fh/exportfs_decode_fh helpers for NFSD to call
instead of poking into exportfs guts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 21 insertions, 1 deletions

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index dd132bb7b8f8..db86006956b0 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -3,6 +3,7 @@
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/module.h>
+#include <linux/mount.h>
 #include <linux/namei.h>
 
 struct export_operations export_op_default;
@@ -468,6 +469,26 @@ static struct dentry *export_decode_fh(struct super_block *sb, __u32 *fh, int fh
                                    acceptable, context);
 }
 
+int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
+                int connectable)
+{
+        struct export_operations *nop = dentry->d_sb->s_export_op;
+
+        return CALL(nop, encode_fh)(dentry, fh, max_len, connectable);
+}
+EXPORT_SYMBOL_GPL(exportfs_encode_fh);
+
+struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh, int fh_len,
+                int fileid_type, int (*acceptable)(void *, struct dentry *),
+                void *context)
+{
+        struct export_operations *nop = mnt->mnt_sb->s_export_op;
+
+        return CALL(nop, decode_fh)(mnt->mnt_sb, fh, fh_len, fileid_type,
+                        acceptable, context);
+}
+EXPORT_SYMBOL_GPL(exportfs_decode_fh);
+
 struct export_operations export_op_default = {
         .decode_fh      = export_decode_fh,
         .encode_fh      = export_encode_fh,
@@ -477,7 +498,6 @@ struct export_operations export_op_default = {
         .get_dentry     = get_dentry,
 };
 
-EXPORT_SYMBOL(export_op_default);
 EXPORT_SYMBOL(find_exported_dentry);
 
 MODULE_LICENSE("GPL");