exportfs: add fid type

This patchset is a medium scale rewrite of the export operations interface.
The goal is to make the interface less complex, and easier to understand from
the filesystem side, aswell as preparing generic support for exporting of
64bit inode numbers.

This touches all nfs exporting filesystems, and I've done testing on all of
the filesystems I have here locally (xfs, ext2, ext3, reiserfs, jfs)

This patch:

Add a structured fid type so that we don't have to pass an array of u32 values
around everywhere.  It's a union of possible layouts.

As a start there's only the u32 array and the traditional 32bit inode format,
but there will be more in one of my next patchset when I start to document the
various filehandle formats we have in lowlevel filesystems better.

Also add an enum that gives the various filehandle types human- readable
names.

Note: Some people might think the struct containing an anonymous union is
ugly, but I didn't want to pass around a raw union type.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 18 deletions

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 8adb32a9387a..813011aad700 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -434,29 +434,29 @@ out:
  * can be used to check that it is still valid.  It places them in the
  * filehandle fragment where export_decode_fh expects to find them.
  */
-static int export_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
-		   int connectable)
+static int export_encode_fh(struct dentry *dentry, struct fid *fid,
+		int *max_len, int connectable)
 {
 	struct inode * inode = dentry->d_inode;
 	int len = *max_len;
-	int type = 1;
+	int type = FILEID_INO32_GEN;
 	
 	if (len < 2 || (connectable && len < 4))
 		return 255;
 
 	len = 2;
-	fh[0] = inode->i_ino;
-	fh[1] = inode->i_generation;
+	fid->i32.ino = inode->i_ino;
+	fid->i32.gen = inode->i_generation;
 	if (connectable && !S_ISDIR(inode->i_mode)) {
 		struct inode *parent;
 
 		spin_lock(&dentry->d_lock);
 		parent = dentry->d_parent->d_inode;
-		fh[2] = parent->i_ino;
-		fh[3] = parent->i_generation;
+		fid->i32.parent_ino = parent->i_ino;
+		fid->i32.parent_gen = parent->i_generation;
 		spin_unlock(&dentry->d_lock);
 		len = 4;
-		type = 2;
+		type = FILEID_INO32_GEN_PARENT;
 	}
 	*max_len = len;
 	return type;
@@ -494,34 +494,34 @@ 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 exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
 		int connectable)
 {
  	struct export_operations *nop = dentry->d_sb->s_export_op;
 	int error;
 
 	if (nop->encode_fh)
-		error = nop->encode_fh(dentry, fh, max_len, connectable);
+		error = nop->encode_fh(dentry, fid->raw, max_len, connectable);
 	else
-		error = export_encode_fh(dentry, fh, max_len, connectable);
+		error = export_encode_fh(dentry, fid, max_len, connectable);
 
 	return error;
 }
 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 dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
+		int fh_len, int fileid_type,
+		int (*acceptable)(void *, struct dentry *), void *context)
 {
 	struct export_operations *nop = mnt->mnt_sb->s_export_op;
 	struct dentry *result;
 
 	if (nop->decode_fh) {
-		result = nop->decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
-			acceptable, context);
+		result = nop->decode_fh(mnt->mnt_sb, fid->raw, fh_len,
+					fileid_type, acceptable, context);
 	} else {
-		result = export_decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
-			acceptable, context);
+		result = export_decode_fh(mnt->mnt_sb, fid->raw, fh_len,
+					  fileid_type, acceptable, context);
 	}
 
 	return result;