From: Neil Brown <neilb@nbeee.brown>
Date: Wed, 14 Jul 2010 10:30:42 +0000 (+1000)
Subject: Add export operations for NFS export.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=f99f8befed842079f9a11cba6f520b056150f7ce;p=LaFS.git

Add export operations for NFS export.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/super.c b/super.c
index e3104da..6179855 100644
--- a/super.c
+++ b/super.c
@@ -11,8 +11,10 @@
 #include	<linux/crc32.h>
 #include	<linux/statfs.h>
 #include	<linux/mount.h>
+#include	<linux/exportfs.h>
 
 static struct super_operations lafs_sops;
+static const struct export_operations lafs_export_ops;
 
 /*---------------------------------------------------------------------
  * Write out state and super blocks
@@ -620,6 +622,7 @@ lafs_load(struct options *op, int newest)
 			dv->stateaddr[j] = le64_to_cpu(dv->devblk->stateaddr[j]);
 
 		dv->sb->s_op = &lafs_sops;
+		dv->sb->s_export_op = &lafs_export_ops;
 		dv->sb->s_root = NULL;
 	}
 	return fs;
@@ -936,6 +939,57 @@ static void __exit lafs_exit(void)
 	lafs_ihash_free();
 }
 
+static struct inode *lafs_nfs_get_inode(struct super_block *sb,
+					u64 ino, u32 generation)
+{
+	struct inode *inode;
+
+	inode = lafs_iget(sb, ino, SYNC);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (generation && inode->i_generation != generation) {
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+
+	return inode;
+}
+
+static struct dentry *lafs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    lafs_nfs_get_inode);
+}
+
+static struct dentry *lafs_fh_to_parent(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    lafs_nfs_get_inode);
+}
+
+static struct dentry *lafs_get_parent(struct dentry *child)
+{
+	ino_t inum = LAFSI(child->d_inode)->md.file.parent;
+	struct inode *inode = lafs_iget(child->d_inode->i_sb, inum, SYNC);
+	struct dentry *parent;
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	parent = d_alloc_anon(inode);
+	if (!parent) {
+		iput(inode);
+		parent = ERR_PTR(-ENOMEM);
+	}
+	return parent;
+}
+
+static const struct export_operations lafs_export_ops = {
+	.fh_to_dentry = lafs_fh_to_dentry,
+	.fh_to_parent = lafs_fh_to_parent,
+	.get_parent = lafs_get_parent,
+};
+
 static struct inode *lafs_alloc_inode(struct super_block *sb)
 {
 	struct lafs_inode *li;