#include <linux/ceph/ceph_debug.h>

  
  #include <linux/exportfs.h>

  #include <linux/slab.h>

  #include <asm/unaligned.h>
  
  #include "super.h"

  #include "mds_client.h"

  
  /*

   * Basic fh
   */
  struct ceph_nfs_fh {
  	u64 ino;
  } __attribute__ ((packed));
  
  /*

   * Larger fh that includes parent ino.

   */
  struct ceph_nfs_confh {
  	u64 ino, parent_ino;

  } __attribute__ ((packed));

  static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
  			  struct inode *parent_inode)

  {

  	int type;

  	struct ceph_nfs_fh *fh = (void *)rawfh;
  	struct ceph_nfs_confh *cfh = (void *)rawfh;

  	int connected_handle_length = sizeof(*cfh)/4;
  	int handle_length = sizeof(*fh)/4;

  
  	/* don't re-export snaps */
  	if (ceph_snap(inode) != CEPH_NOSNAP)
  		return -EINVAL;

  	if (parent_inode && (*max_len < connected_handle_length)) {
  		*max_len = connected_handle_length;
  		return FILEID_INVALID;
  	} else if (*max_len < handle_length) {
  		*max_len = handle_length;
  		return FILEID_INVALID;
  	}

  	if (parent_inode) {
  		dout("encode_fh %llx with parent %llx
  ",
  		     ceph_ino(inode), ceph_ino(parent_inode));

  		cfh->ino = ceph_ino(inode);

  		cfh->parent_ino = ceph_ino(parent_inode);

  		*max_len = connected_handle_length;

  		type = FILEID_INO32_GEN_PARENT;

  	} else {

  		dout("encode_fh %llx
  ", ceph_ino(inode));
  		fh->ino = ceph_ino(inode);

  		*max_len = handle_length;

  		type = FILEID_INO32_GEN;

  	}
  	return type;
  }

  static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)

  {

  	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;

  	struct inode *inode;
  	struct dentry *dentry;
  	struct ceph_vino vino;
  	int err;

  	vino.ino = ino;

  	vino.snap = CEPH_NOSNAP;
  	inode = ceph_find_inode(sb, vino);

  	if (!inode) {
  		struct ceph_mds_request *req;
  
  		req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
  					       USE_ANY_MDS);
  		if (IS_ERR(req))
  			return ERR_CAST(req);
  
  		req->r_ino1 = vino;
  		req->r_num_caps = 1;
  		err = ceph_mdsc_do_request(mdsc, NULL, req);

  		inode = req->r_target_inode;
  		if (inode)

  			ihold(inode);

  		ceph_mdsc_put_request(req);

  		if (!inode)
  			return ERR_PTR(-ESTALE);
  	}

  
  	dentry = d_obtain_alias(inode);

  	if (IS_ERR(dentry)) {

  		iput(inode);

  		return dentry;

  	}
  	err = ceph_init_dentry(dentry);

  	if (err < 0) {

  		dput(dentry);

  		return ERR_PTR(err);
  	}

  	dout("__fh_to_dentry %llx %p dentry %p
  ", ino, inode, dentry);

  	return dentry;
  }
  
  /*

   * convert regular fh to dentry

   */

  static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
  					struct fid *fid,
  					int fh_len, int fh_type)

  {

  	struct ceph_nfs_fh *fh = (void *)fid->raw;

  	if (fh_type != FILEID_INO32_GEN  &&
  	    fh_type != FILEID_INO32_GEN_PARENT)
  		return NULL;
  	if (fh_len < sizeof(*fh) / 4)
  		return NULL;

  	dout("fh_to_dentry %llx
  ", fh->ino);
  	return __fh_to_dentry(sb, fh->ino);

  }

  static struct dentry *__get_parent(struct super_block *sb,
  				   struct dentry *child, u64 ino)
  {
  	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
  	struct ceph_mds_request *req;
  	struct inode *inode;
  	struct dentry *dentry;
  	int err;
  
  	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
  				       USE_ANY_MDS);
  	if (IS_ERR(req))
  		return ERR_CAST(req);
  
  	if (child) {

  		req->r_inode = d_inode(child);
  		ihold(d_inode(child));

  	} else {
  		req->r_ino1 = (struct ceph_vino) {
  			.ino = ino,
  			.snap = CEPH_NOSNAP,
  		};
  	}
  	req->r_num_caps = 1;
  	err = ceph_mdsc_do_request(mdsc, NULL, req);
  	inode = req->r_target_inode;
  	if (inode)
  		ihold(inode);
  	ceph_mdsc_put_request(req);
  	if (!inode)
  		return ERR_PTR(-ENOENT);
  
  	dentry = d_obtain_alias(inode);
  	if (IS_ERR(dentry)) {
  		iput(inode);
  		return dentry;
  	}
  	err = ceph_init_dentry(dentry);
  	if (err < 0) {
  		dput(dentry);
  		return ERR_PTR(err);
  	}
  	dout("__get_parent ino %llx parent %p ino %llx.%llx
  ",

  	     child ? ceph_ino(d_inode(child)) : ino,

  	     dentry, ceph_vinop(inode));
  	return dentry;
  }

  static struct dentry *ceph_get_parent(struct dentry *child)

  {
  	/* don't re-export snaps */

  	if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)

  		return ERR_PTR(-EINVAL);
  
  	dout("get_parent %p ino %llx.%llx
  ",

  	     child, ceph_vinop(d_inode(child)));

  	return __get_parent(child->d_sb, child, 0);
  }

  /*

   * convert regular fh to parent

   */
  static struct dentry *ceph_fh_to_parent(struct super_block *sb,

  					struct fid *fid,

  					int fh_len, int fh_type)
  {
  	struct ceph_nfs_confh *cfh = (void *)fid->raw;

  	struct dentry *dentry;

  	if (fh_type != FILEID_INO32_GEN_PARENT)
  		return NULL;

  	if (fh_len < sizeof(*cfh) / 4)

  		return NULL;

  	dout("fh_to_parent %llx
  ", cfh->parent_ino);
  	dentry = __get_parent(sb, NULL, cfh->ino);
  	if (IS_ERR(dentry) && PTR_ERR(dentry) == -ENOENT)
  		dentry = __fh_to_dentry(sb, cfh->parent_ino);

  	return dentry;
  }

  static int ceph_get_name(struct dentry *parent, char *name,
  			 struct dentry *child)
  {
  	struct ceph_mds_client *mdsc;
  	struct ceph_mds_request *req;
  	int err;

  	mdsc = ceph_inode_to_client(d_inode(child))->mdsc;

  	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
  				       USE_ANY_MDS);
  	if (IS_ERR(req))
  		return PTR_ERR(req);

  	inode_lock(d_inode(parent));

  	req->r_inode = d_inode(child);
  	ihold(d_inode(child));
  	req->r_ino2 = ceph_vino(d_inode(parent));
  	req->r_locked_dir = d_inode(parent);

  	req->r_num_caps = 2;
  	err = ceph_mdsc_do_request(mdsc, NULL, req);

  	inode_unlock(d_inode(parent));

  
  	if (!err) {
  		struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
  		memcpy(name, rinfo->dname, rinfo->dname_len);
  		name[rinfo->dname_len] = 0;
  		dout("get_name %p ino %llx.%llx name %s
  ",

  		     child, ceph_vinop(d_inode(child)), name);

  	} else {
  		dout("get_name %p ino %llx.%llx err %d
  ",

  		     child, ceph_vinop(d_inode(child)), err);

  	}
  
  	ceph_mdsc_put_request(req);
  	return err;
  }

  const struct export_operations ceph_export_ops = {
  	.encode_fh = ceph_encode_fh,
  	.fh_to_dentry = ceph_fh_to_dentry,
  	.fh_to_parent = ceph_fh_to_parent,

  	.get_parent = ceph_get_parent,

  	.get_name = ceph_get_name,

  };