[PATCH 4/4] Reinstate NFS exportability

David Woodhouse
2008-08-09T20:03:46Z

Now that the readdir/lookup deadlock issues have been dealt with, we can
export JFFS2 file systems again.

(For now, you have to specify fsid manually; we should add a method to
the export_ops to handle that too.)

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
fs/jffs2/super.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index efd4012..7f03a28 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -22,6 +22,7 @@
#include <linux/mtd/super.h>
#include <linux/ctype.h>
#include <linux/namei.h>
+#include <linux/exportfs.h>
#include "compr.h"
#include "nodelist.h"

@@ -62,6 +63,63 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
return 0;
}

+static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
+ uint32_t generation)
+{
+ return jffs2_iget(sb, ino);
+}
+
+static struct dentry *jffs2_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,
+ jffs2_nfs_get_inode);
+}
+
+static struct dentry *jffs2_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,
+ jffs2_nfs_get_inode);
+}
+
+static struct dentry *jffs2_get_parent(struct dentry *child)
+{
+ struct jffs2_inode_info *f;
+ struct dentry *parent;
+ struct inode *inode;
+ uint32_t pino;
+
+ BUG_ON(!S_ISDIR(child->d_inode->i_mode));
+
+ f = JFFS2_INODE_INFO(child->d_inode);
+
+ pino = f->inocache->pino_nlink;
+
+ JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
+ f->inocache->ino, pino);
+
+ inode = jffs2_iget(child->d_inode->i_sb, pino);
+ if (IS_ERR(inode)) {
+ JFFS2_ERROR("Failed to get inode #%u: %ld\n", pino,
+ PTR_ERR(inode));
+ return ERR_CAST(inode);
+ }
+
+ parent = d_alloc_anon(inode);
+ if (!parent) {
+ iput(inode);
+ parent = ERR_PTR(-ENOMEM);
+ }
+ return parent;
+}
+
+static struct export_operations jffs2_export_ops = {
+ .get_parent = jffs2_get_parent,
+ .fh_to_dentry = jffs2_fh_to_dentry,
+ .fh_to_parent = jffs2_fh_to_parent,
+};
+
static const struct super_operations jffs2_super_operations =
{
.alloc_inode = jffs2_alloc_inode,
@@ -104,6 +162,7 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
spin_lock_init(&c->inocache_lock);

sb->s_op = &jffs2_super_operations;
+ sb->s_export_op = &jffs2_export_ops;
sb->s_flags = sb->s_flags | MS_NOATIME;
sb->s_xattr = jffs2_xattr_handlers;
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
--
1.5.5.1

--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation