/* cnode related routines for the coda kernel code
     (C) 1996 Peter Braam
     */
  
  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/time.h>
  
  #include <linux/coda.h>
  #include <linux/coda_psdev.h>
  #include "coda_linux.h"
  
  static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
  {
  	return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
  }
  
  static const struct inode_operations coda_symlink_inode_operations = {
  	.readlink	= generic_readlink,
  	.follow_link	= page_follow_link_light,
  	.put_link	= page_put_link,
  	.setattr	= coda_setattr,
  };
  
  /* cnode.c */
  static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
  {
          coda_vattr_to_iattr(inode, attr);
  
          if (S_ISREG(inode->i_mode)) {
                  inode->i_op = &coda_file_inode_operations;
                  inode->i_fop = &coda_file_operations;
          } else if (S_ISDIR(inode->i_mode)) {
                  inode->i_op = &coda_dir_inode_operations;
                  inode->i_fop = &coda_dir_operations;
          } else if (S_ISLNK(inode->i_mode)) {
  		inode->i_op = &coda_symlink_inode_operations;
  		inode->i_data.a_ops = &coda_symlink_aops;
  		inode->i_mapping = &inode->i_data;
  	} else
                  init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
  }
  
  static int coda_test_inode(struct inode *inode, void *data)
  {
  	struct CodaFid *fid = (struct CodaFid *)data;
  	struct coda_inode_info *cii = ITOC(inode);
  	return coda_fideq(&cii->c_fid, fid);
  }
  
  static int coda_set_inode(struct inode *inode, void *data)
  {
  	struct CodaFid *fid = (struct CodaFid *)data;
  	struct coda_inode_info *cii = ITOC(inode);
  	cii->c_fid = *fid;
  	return 0;
  }
  
  struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
  			 struct coda_vattr * attr)
  {
  	struct inode *inode;
  	struct coda_inode_info *cii;
  	unsigned long hash = coda_f2i(fid);
  
  	inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
  
  	if (!inode)
  		return ERR_PTR(-ENOMEM);
  
  	if (inode->i_state & I_NEW) {
  		cii = ITOC(inode);
  		/* we still need to set i_ino for things like stat(2) */
  		inode->i_ino = hash;
  		/* inode is locked and unique, no need to grab cii->c_lock */
  		cii->c_mapcount = 0;
  		unlock_new_inode(inode);
  	}
  
  	/* always replace the attributes, type might have changed */
  	coda_fill_inode(inode, attr);
  	return inode;
  }
  
  /* this is effectively coda_iget:
     - get attributes (might be cached)
     - get the inode for the fid using vfs iget
     - link the two up if this is needed
     - fill in the attributes
  */
  struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
  {
          struct coda_vattr attr;
  	struct inode *inode;
          int error;
          
  	/* We get inode numbers from Venus -- see venus source */
  	error = venus_getattr(sb, fid, &attr);
  	if (error)
  		return ERR_PTR(error);
  
  	inode = coda_iget(sb, fid, &attr);
  	if (IS_ERR(inode))
  		printk("coda_cnode_make: coda_iget failed
  ");
  	return inode;
  }
  
  
  /* Although we treat Coda file identifiers as immutable, there is one
   * special case for files created during a disconnection where they may
   * not be globally unique. When an identifier collision is detected we
   * first try to flush the cached inode from the kernel and finally
   * resort to renaming/rehashing in-place. Userspace remembers both old
   * and new values of the identifier to handle any in-flight upcalls.
   * The real solution is to use globally unique UUIDs as identifiers, but
   * retrofitting the existing userspace code for this is non-trivial. */
  void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 
  		      struct CodaFid *newfid)
  {
  	struct coda_inode_info *cii = ITOC(inode);
  	unsigned long hash = coda_f2i(newfid);
  	
  	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
  
  	/* replace fid and rehash inode */
  	/* XXX we probably need to hold some lock here! */
  	remove_inode_hash(inode);
  	cii->c_fid = *newfid;
  	inode->i_ino = hash;
  	__insert_inode_hash(inode, hash);
  }
  
  /* convert a fid to an inode. */
  struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 
  {
  	struct inode *inode;
  	unsigned long hash = coda_f2i(fid);
  
  	if ( !sb ) {
  		printk("coda_fid_to_inode: no sb!
  ");
  		return NULL;
  	}
  
  	inode = ilookup5(sb, hash, coda_test_inode, fid);
  	if ( !inode )
  		return NULL;
  
  	/* we should never see newly created inodes because we intentionally
  	 * fail in the initialization callback */
  	BUG_ON(inode->i_state & I_NEW);
  
  	return inode;
  }
  
  /* the CONTROL inode is made without asking attributes from Venus */
  struct inode *coda_cnode_makectl(struct super_block *sb)
  {
  	struct inode *inode = new_inode(sb);
  	if (inode) {
  		inode->i_ino = CTL_INO;
  		inode->i_op = &coda_ioctl_inode_operations;
  		inode->i_fop = &coda_ioctl_operations;
  		inode->i_mode = 0444;
  		return inode;
  	}
  	return ERR_PTR(-ENOMEM);
  }