// SPDX-License-Identifier: GPL-2.0

  /*
   * (C) 2001 Clemson University and The University of Chicago
   *
   * See COPYING in top-level directory.
   */
  
  /*
   *  Implementation of dentry (directory cache) functions.
   */
  
  #include "protocol.h"

  #include "orangefs-kernel.h"

  
  /* Returns 1 if dentry can still be trusted, else 0. */

  static int orangefs_revalidate_lookup(struct dentry *dentry)

  {
  	struct dentry *parent_dentry = dget_parent(dentry);
  	struct inode *parent_inode = parent_dentry->d_inode;

  	struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode);

  	struct inode *inode = dentry->d_inode;

  	struct orangefs_kernel_op_s *new_op;

  	int ret = 0;
  	int err = 0;
  
  	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.
  ", __func__);

  	new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP);

  	if (!new_op)
  		goto out_put_parent;

  	new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;

  	new_op->upcall.req.lookup.parent_refn = parent->refn;
  	strncpy(new_op->upcall.req.lookup.d_name,
  		dentry->d_name.name,

  		ORANGEFS_NAME_MAX - 1);

  
  	gossip_debug(GOSSIP_DCACHE_DEBUG,
  		     "%s:%s:%d interrupt flag [%d]
  ",
  		     __FILE__,
  		     __func__,
  		     __LINE__,
  		     get_interruptible_flag(parent_inode));

  	err = service_operation(new_op, "orangefs_lookup",

  			get_interruptible_flag(parent_inode));

  
  	/* Positive dentry: reject if error or not the same inode. */
  	if (inode) {
  		if (err) {
  			gossip_debug(GOSSIP_DCACHE_DEBUG,
  			    "%s:%s:%d lookup failure.
  ",
  			    __FILE__, __func__, __LINE__);
  			goto out_drop;
  		}
  		if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
  		    inode)) {
  			gossip_debug(GOSSIP_DCACHE_DEBUG,
  			    "%s:%s:%d no match.
  ",
  			    __FILE__, __func__, __LINE__);
  			goto out_drop;
  		}
  
  	/* Negative dentry: reject if success or error other than ENOENT. */
  	} else {
  		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.
  ",
  		    __func__);
  		if (!err || err != -ENOENT) {
  			if (new_op->downcall.status != 0)
  				gossip_debug(GOSSIP_DCACHE_DEBUG,
  				    "%s:%s:%d lookup failure.
  ",
  				    __FILE__, __func__, __LINE__);
  			goto out_drop;
  		}

  	}

  	orangefs_set_timeout(dentry);

  	ret = 1;
  out_release_op:
  	op_release(new_op);
  out_put_parent:
  	dput(parent_dentry);
  	return ret;
  out_drop:

  	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed
  ",
  	    __FILE__, __func__, __LINE__);

  	goto out_release_op;
  }
  
  /*
   * Verify that dentry is valid.
   *

   * Should return 1 if dentry can still be trusted, else 0.

   */

  static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags)

  {

  	int ret;

  	unsigned long time = (unsigned long) dentry->d_fsdata;

  	if (time_before(jiffies, time))

  		return 1;

  	if (flags & LOOKUP_RCU)
  		return -ECHILD;
  
  	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.
  ",
  		     __func__, dentry);

  	/* skip root handle lookups. */
  	if (dentry->d_inode && is_root_handle(dentry->d_inode))
  		return 1;
  
  	/*
  	 * If this passes, the positive dentry still exists or the negative
  	 * dentry still does not exist.
  	 */

  	if (!orangefs_revalidate_lookup(dentry))

  		return 0;

  	/* We do not need to continue with negative dentries. */

  	if (!dentry->d_inode) {
  		gossip_debug(GOSSIP_DCACHE_DEBUG,
  		    "%s: negative dentry or positive dentry and inode valid.
  ",
  		    __func__);
  		return 1;
  	}

  	/* Now we must perform a getattr to validate the inode contents. */

  	ret = orangefs_inode_check_changed(dentry->d_inode);

  	if (ret < 0) {
  		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.
  ",
  		    __FILE__, __func__, __LINE__);

  		return 0;
  	}

  	return !ret;

  }

  const struct dentry_operations orangefs_dentry_operations = {
  	.d_revalidate = orangefs_d_revalidate,

  };